WorldWideScience

Sample records for reference field model

  1. The International Geomagnetic Reference Field (IGRF) generation 12: BGS candidates and final models

    OpenAIRE

    Beggan, Ciaran D.; Hamilton, Brian; Taylor, Victoria; Macmillan, Susan; Thomson, Alan

    2015-01-01

    The International Geomagnetic Reference Field (IGRF) model is a reference main field magnetic model updated on a quinquennial basis. The latest revision (generation 12) was released in January 2015. The IGRF-12 consists of a definitive model (DGRF2010) of the main field for 2010.0, a model for the field at 2015.0 (IGRF2015) and a prediction of secular variation (IGRF-12 SV) for the forthcoming five years until 2020.0. The remaining coefficients of IGRF-12 are unchanged from IGRF-11. Nin...

  2. International Geomagnetic Reference Field

    DEFF Research Database (Denmark)

    Finlay, Chris; Maus, S.; Beggan, C. D.

    2010-01-01

    The eleventh generation of the International Geomagnetic Reference Field (IGRF) was adopted in December 2009 by the International Association of Geomagnetism and Aeronomy Working Group V‐MOD. It updates the previous IGRF generation with a definitive main field model for epoch 2005.0, a main field...... model for epoch 2010.0, and a linear predictive secular variation model for 2010.0–2015.0. In this note the equations defining the IGRF model are provided along with the spherical harmonic coefficients for the eleventh generation. Maps of the magnetic declination, inclination and total intensity...

  3. Thermal radiation transfer calculations in combustion fields using the SLW model coupled with a modified reference approach

    Science.gov (United States)

    Darbandi, Masoud; Abrar, Bagher

    2018-01-01

    The spectral-line weighted-sum-of-gray-gases (SLW) model is considered as a modern global model, which can be used in predicting the thermal radiation heat transfer within the combustion fields. The past SLW model users have mostly employed the reference approach to calculate the local values of gray gases' absorption coefficient. This classical reference approach assumes that the absorption spectra of gases at different thermodynamic conditions are scalable with the absorption spectrum of gas at a reference thermodynamic state in the domain. However, this assumption cannot be reasonable in combustion fields, where the gas temperature is very different from the reference temperature. Consequently, the results of SLW model incorporated with the classical reference approach, say the classical SLW method, are highly sensitive to the reference temperature magnitude in non-isothermal combustion fields. To lessen this sensitivity, the current work combines the SLW model with a modified reference approach, which is a particular one among the eight possible reference approach forms reported recently by Solovjov, et al. [DOI: 10.1016/j.jqsrt.2017.01.034, 2017]. The combination is called "modified SLW method". This work shows that the modified reference approach can provide more accurate total emissivity calculation than the classical reference approach if it is coupled with the SLW method. This would be particularly helpful for more accurate calculation of radiation transfer in highly non-isothermal combustion fields. To approve this, we use both the classical and modified SLW methods and calculate the radiation transfer in such fields. It is shown that the modified SLW method can almost eliminate the sensitivity of achieved results to the chosen reference temperature in treating highly non-isothermal combustion fields.

  4. Basic Restriction and Reference Level in Anatomically-based Japanese Models for Low-Frequency Electric and Magnetic Field Exposures

    Science.gov (United States)

    Takano, Yukinori; Hirata, Akimasa; Fujiwara, Osamu

    Human exposed to electric and/or magnetic fields at low frequencies may cause direct effect such as nerve stimulation and excitation. Therefore, basic restriction is regulated in terms of induced current density in the ICNIRP guidelines and in-situ electric field in the IEEE standard. External electric or magnetic field which does not produce induced quantities exceeding the basic restriction is used as a reference level. The relationship between the basic restriction and reference level for low-frequency electric and magnetic fields has been investigated using European anatomic models, while limited for Japanese model, especially for electric field exposures. In addition, that relationship has not well been discussed. In the present study, we calculated the induced quantities in anatomic Japanese male and female models exposed to electric and magnetic fields at reference level. A quasi static finite-difference time-domain (FDTD) method was applied to analyze this problem. As a result, spatially averaged induced current density was found to be more sensitive to averaging algorithms than that of in-situ electric field. For electric and magnetic field exposure at the ICNIRP reference level, the maximum values of the induced current density for different averaging algorithm were smaller than the basic restriction for most cases. For exposures at the reference level in the IEEE standard, the maximum electric fields in the brain were larger than the basic restriction in the brain while smaller for the spinal cord and heart.

  5. The International Geomagnetic Reference Field: the twelfth generation

    Science.gov (United States)

    Thebault, Erwan; Finlay, Christopher; The IGRF Working Group

    2015-04-01

    The IGRF is an internationally-agreed reference model of the Earth's magnetic field produced under the auspices of the International Association of Geomagnetism and Aeronomy. The IGRF-12 is the latest update of this well-known model which is used each year by many thousands of users for both industrial and scientific purposes. In October 2014, ten institutions worldwide have made contributions to the IGRF. These models were evaluated and the twelfth generation of the International Geomagnetic Reference Field (IGRF) was adopted in December 2014. In this presentation, we will report on the IGRF activities, briefly describe the candidate models, summarize the evaluation of models performed by different independent teams, show how the IGRF-12 models were calculated and finally discuss some of the main magnetic features of this new model.

  6. International Geomagnetic Reference Field: the 12th generation

    OpenAIRE

    Thébault , Erwan; Finlay , Christopher ,; Beggan , Ciarán ,; Alken , Patrick; Aubert , Julien ,; Barrois , Olivier; Bertrand , François; Bondar , Tatiana; Boness , Axel; Brocco , Laura; Canet , Elisabeth ,; Chambodut , Aude; Chulliat , Arnaud ,; Coïsson , Pierdavide ,; Civet , François

    2015-01-01

    International audience; The 12th generation of the International Geomagnetic Reference Field (IGRF) was adopted in December 2014 by the Working Group V-MOD appointed by the International Association of Geomagnetism and Aeronomy (IAGA). It updates the previous IGRF generation with a definitive main field model for epoch 2010.0, a main field model for epoch 2015.0, and a linear annual predictive secular variation model for 2015.0-2020.0. Here, we present the equations defining the IGRF model, p...

  7. International Geomagnetic Reference Field: the 12th generation

    DEFF Research Database (Denmark)

    Thébault, Erwan; Finlay, Chris; Beggan, Ciarán D.

    2015-01-01

    The 12th generation of the International Geomagnetic Reference Field (IGRF) was adopted in December 2014 by the Working Group V-MOD appointed by the International Association of Geomagnetism and Aeronomy (IAGA). It updates the previous IGRF generation with a definitive main field model for epoch ...

  8. A mapping closure for turbulent scalar mixing using a time-evolving reference field

    Science.gov (United States)

    Girimaji, Sharath S.

    1992-01-01

    A general mapping-closure approach for modeling scalar mixing in homogeneous turbulence is developed. This approach is different from the previous methods in that the reference field also evolves according to the same equations as the physical scalar field. The use of a time-evolving Gaussian reference field results in a model that is similar to the mapping closure model of Pope (1991), which is based on the methodology of Chen et al. (1989). Both models yield identical relationships between the scalar variance and higher-order moments, which are in good agreement with heat conduction simulation data and can be consistent with any type of epsilon(phi) evolution. The present methodology can be extended to any reference field whose behavior is known. The possibility of a beta-pdf reference field is explored. The shortcomings of the mapping closure methods are discussed, and the limit at which the mapping becomes invalid is identified.

  9. Simulation of the spherical experimental assemblies for the mixed neutron-gamma reference fields implementation

    International Nuclear Information System (INIS)

    Kluson, J.; Jansky, B.

    2009-01-01

    Reference mixed neutron-gamma fields are used for test and calibration of dosimetric and spectrometric systems, intercomparison measurements, and benchmark tests and represent experimental base for reactor studies. Set of the spherical experimental assemblies for the mixed neutron-gamma reference fields implementation was build in the NRI Rez. Extended sets of measurements and simulation calculations were done to describe the reference mixed field dosimetry and spectral characteristics with best achievable precision. The Monte Carlo technique was used for different experimental setups models description, comparison and verification and field characteristics simulation. Effects (hardly distinguishable experimentally) were also studied ( contributions from individual parts of experimental setup, field individual components and next effects as shadow shield cones transparency, etc.). Some results and main conclusions of these studies and calculations are presented and discussed. (authors)

  10. Simulation of the spherical experimental assemblies for the mixed neutron-gamma reference fields implementation

    International Nuclear Information System (INIS)

    Kluson, J.; Jansky, B.

    2008-01-01

    Reference mixed neutron-gamma fields are used for test and calibration of dosimetric and spectrometric systems, intercomparison measurements, and benchmark tests and represent experimental base for reactor studies. Set of the spherical experimental assemblies for the mixed neutron-gamma reference fields implementation was build in the NRI Rez. Extended sets of measurements and simulation calculations were done to describe the reference mixed field dosimetry and spectral characteristics with best achievable precision. The Monte Carlo technique was used for different experimental setups models description, comparison and verification and field characteristics simulation. Effects (hardly distinguishable experimentally) were also studied ( contributions from individual parts of experimental setup, field individual components and next effects as shadow shield cones transparency, etc.). Some results and main conclusions of these studies and calculations are presented and discussed. (authors)

  11. Uncertainty Quantification in Geomagnetic Field Modeling

    Science.gov (United States)

    Chulliat, A.; Nair, M. C.; Alken, P.; Meyer, B.; Saltus, R.; Woods, A.

    2017-12-01

    Geomagnetic field models are mathematical descriptions of the various sources of the Earth's magnetic field, and are generally obtained by solving an inverse problem. They are widely used in research to separate and characterize field sources, but also in many practical applications such as aircraft and ship navigation, smartphone orientation, satellite attitude control, and directional drilling. In recent years, more sophisticated models have been developed, thanks to the continuous availability of high quality satellite data and to progress in modeling techniques. Uncertainty quantification has become an integral part of model development, both to assess the progress made and to address specific users' needs. Here we report on recent advances made by our group in quantifying the uncertainty of geomagnetic field models. We first focus on NOAA's World Magnetic Model (WMM) and the International Geomagnetic Reference Field (IGRF), two reference models of the main (core) magnetic field produced every five years. We describe the methods used in quantifying the model commission error as well as the omission error attributed to various un-modeled sources such as magnetized rocks in the crust and electric current systems in the atmosphere and near-Earth environment. A simple error model was derived from this analysis, to facilitate usage in practical applications. We next report on improvements brought by combining a main field model with a high resolution crustal field model and a time-varying, real-time external field model, like in NOAA's High Definition Geomagnetic Model (HDGM). The obtained uncertainties are used by the directional drilling industry to mitigate health, safety and environment risks.

  12. Evaluation of local electric fields generated by transcranial direct current stimulation with an extracephalic reference electrode based on realistic 3D body modeling

    Science.gov (United States)

    Im, Chang-Hwan; Park, Ji-Hye; Shim, Miseon; Chang, Won Hyuk; Kim, Yun-Hee

    2012-04-01

    In this study, local electric field distributions generated by transcranial direct current stimulation (tDCS) with an extracephalic reference electrode were evaluated to address extracephalic tDCS safety issues. To this aim, we generated a numerical model of an adult male human upper body and applied the 3D finite element method to electric current conduction analysis. In our simulations, the active electrode was placed over the left primary motor cortex (M1) and the reference electrode was placed at six different locations: over the right temporal lobe, on the right supraorbital region, on the right deltoid, on the left deltoid, under the chin, and on the right buccinator muscle. The maximum current density and electric field intensity values in the brainstem generated by the extracephalic reference electrodes were comparable to, or even less than, those generated by the cephalic reference electrodes. These results suggest that extracephalic reference electrodes do not lead to unwanted modulation of the brainstem cardio-respiratory and autonomic centers, as indicated by recent experimental studies. The volume energy density was concentrated at the neck area by the use of deltoid reference electrodes, but was still smaller than that around the active electrode locations. In addition, the distributions of elicited cortical electric fields demonstrated that the use of extracephalic reference electrodes might allow for the robust prediction of cortical modulations with little dependence on the reference electrode locations.

  13. Computational Model Prediction and Biological Validation Using Simplified Mixed Field Exposures for the Development of a GCR Reference Field

    Science.gov (United States)

    Hada, M.; Rhone, J.; Beitman, A.; Saganti, P.; Plante, I.; Ponomarev, A.; Slaba, T.; Patel, Z.

    2018-01-01

    The yield of chromosomal aberrations has been shown to increase in the lymphocytes of astronauts after long-duration missions of several months in space. Chromosome exchanges, especially translocations, are positively correlated with many cancers and are therefore a potential biomarker of cancer risk associated with radiation exposure. Although extensive studies have been carried out on the induction of chromosomal aberrations by low- and high-LET radiation in human lymphocytes, fibroblasts, and epithelial cells exposed in vitro, there is a lack of data on chromosome aberrations induced by low dose-rate chronic exposure and mixed field beams such as those expected in space. Chromosome aberration studies at NSRL will provide the biological validation needed to extend the computational models over a broader range of experimental conditions (more complicated mixed fields leading up to the galactic cosmic rays (GCR) simulator), helping to reduce uncertainties in radiation quality effects and dose-rate dependence in cancer risk models. These models can then be used to answer some of the open questions regarding requirements for a full GCR reference field, including particle type and number, energy, dose rate, and delivery order. In this study, we designed a simplified mixed field beam with a combination of proton, helium, oxygen, and iron ions with shielding or proton, helium, oxygen, and titanium without shielding. Human fibroblasts cells were irradiated with these mixed field beam as well as each single beam with acute and chronic dose rate, and chromosome aberrations (CA) were measured with 3-color fluorescent in situ hybridization (FISH) chromosome painting methods. Frequency and type of CA induced with acute dose rate and chronic dose rates with single and mixed field beam will be discussed. A computational chromosome and radiation-induced DNA damage model, BDSTRACKS (Biological Damage by Stochastic Tracks), was updated to simulate various types of CA induced by

  14. The Egyptian geomagnetic reference field to the Epoch, 2010.0

    Directory of Open Access Journals (Sweden)

    H.A. Deebes

    2017-06-01

    The geomagnetic anomaly maps, the normal geomagnetic field maps with their corresponding secular variation maps, the normal geomagnetic field equations of the geomagnetic elements (EGRF and their corresponding secular variations equations, are outlined. The anomalous sites, as discovered from the anomaly maps are, only, mentioned. In addition, a correlation between the International Geomagnetic Reference Field (IGRF 2010.0 and the Egyptian Geomagnetic Reference Field (EGRF 2010 is indicated.

  15. State diagram of spin-torque oscillator with perpendicular reference layer and planar field generation layer

    Directory of Open Access Journals (Sweden)

    Mengwei Zhang

    2015-06-01

    Full Text Available The state diagram of spin-torque oscillator (STO with perpendicular reference layer (REF and planar field generation layer (FGL was studied by a macrospin model and a micro-magnetic model. The state diagrams are calculated versus the current density, external field and external field angle. It was found that the oscillation in FGL could be controlled by current density combined with external field so as to achieve a wide frequency range. An optimized current and applied field region was given for microwave assisted magnetic recording (MAMR, considering both frequency and output field oscillation amplitude. The results of the macro-spin model were compared with those of the micro-magnetic model. The macro-spin model was qualitatively different from micro-magnetics and experimental results when the current density was large and the FGL was non-uniform.

  16. The 3D Reference Earth Model: Status and Preliminary Results

    Science.gov (United States)

    Moulik, P.; Lekic, V.; Romanowicz, B. A.

    2017-12-01

    In the 20th century, seismologists constructed models of how average physical properties (e.g. density, rigidity, compressibility, anisotropy) vary with depth in the Earth's interior. These one-dimensional (1D) reference Earth models (e.g. PREM) have proven indispensable in earthquake location, imaging of interior structure, understanding material properties under extreme conditions, and as a reference in other fields, such as particle physics and astronomy. Over the past three decades, new datasets motivated more sophisticated efforts that yielded models of how properties vary both laterally and with depth in the Earth's interior. Though these three-dimensional (3D) models exhibit compelling similarities at large scales, differences in the methodology, representation of structure, and dataset upon which they are based, have prevented the creation of 3D community reference models. As part of the REM-3D project, we are compiling and reconciling reference seismic datasets of body wave travel-time measurements, fundamental mode and overtone surface wave dispersion measurements, and normal mode frequencies and splitting functions. These reference datasets are being inverted for a long-wavelength, 3D reference Earth model that describes the robust long-wavelength features of mantle heterogeneity. As a community reference model with fully quantified uncertainties and tradeoffs and an associated publically available dataset, REM-3D will facilitate Earth imaging studies, earthquake characterization, inferences on temperature and composition in the deep interior, and be of improved utility to emerging scientific endeavors, such as neutrino geoscience. Here, we summarize progress made in the construction of the reference long period dataset and present a preliminary version of REM-3D in the upper-mantle. In order to determine the level of detail warranted for inclusion in REM-3D, we analyze the spectrum of discrepancies between models inverted with different subsets of the

  17. SU-E-T-471: Small Field Jaw/MLC Reference Data

    International Nuclear Information System (INIS)

    Kerns, J; Alvarez, P; Followill, D; Lowenstein, J; Molineu, A; Summers, P; Kry, S

    2014-01-01

    Purpose: In recent years the need for small field data of MLCs has increased due to the use of intensity-modulated radiation (IMRT), but moreover the use of stereotactic body radiation (SBRT) has increased, which uses not simply small field sizes, but small jaw and field sizes together. Having reference data for these small fields that is reliable would be invaluable to the physics community. Our study has gathered these values and the data distributions from the Radiological Physics Center's (RPC) site visits between 1990 and the present. Methods: For all measurements, the RPC used a 25 × 25 × 25cm water phantom placed at 100cm SSD. All measurements were made with an Exradin A16 cylindrical ion chamber at an effective depth of 10 cm. A total of 42 Varian machine measurements were used to compose the data for a 6 MV beam and 5 TrueBeam 6 MV flattening filter free (FFF) beams were used for FFF data. Results: Jaw/MLC fields were measured for both 6 MV and 6 MF FFF beams with the jaws and MLCs both at the following field sizes: 6×6, 4×4, 3×3, and 2×2cm. Measurements were normalized to the 10×10 field readings (defined by the jaws and MLC). Spread in the data was minimal and demonstrates a high level of accuracy of acquired data. Conclusion: Small field Jaw/MLC reference data for Varian 6MV and 6 MV FFF beams has been analyzed and presented here, composed of the aggregation of numerous RPC site visits. Obtaining reliable small field data remains difficult, however the RPC has collected high fidelity small field Jaw/MLC data. The data are presented as a reference along with their distributions, in such a way that the physicist can act based upon their own desired agreement with the reference data

  18. Numerical simulation of interior flow field of nuclear model pump

    International Nuclear Information System (INIS)

    Wang Chunlin; Peng Na; Kang Can; Zhao Baitong; Zhang Hao

    2009-01-01

    Reynolds time-averaged N-S equations and the standard k-ε turbulent model were adopted, and three-dimensional non-structural of tetrahedral mesh division was used for modeling. Multiple reference frame model of rotating fluid mechanical model was used, under the design condition, the three-dimensional incompressible turbulent flow of nuclear model pump was simulated, and the results preferably post the characteristics of the interior flow field. This paper first analyzes the total pressure and velocity distribution in the flow field, and then describes the interior flow field characteristics of each part such as the impeller, diffuser and spherical shell, and also discusses the reasons that cause these characteristics. The study results can be used to estimate the performance of nuclear model pump, and will provide some useful references for its hydraulic optimized design. (authors)

  19. A reference model for model-based design of critical infrastructure protection systems

    Science.gov (United States)

    Shin, Young Don; Park, Cheol Young; Lee, Jae-Chon

    2015-05-01

    Today's war field environment is getting versatile as the activities of unconventional wars such as terrorist attacks and cyber-attacks have noticeably increased lately. The damage caused by such unconventional wars has also turned out to be serious particularly if targets are critical infrastructures that are constructed in support of banking and finance, transportation, power, information and communication, government, and so on. The critical infrastructures are usually interconnected to each other and thus are very vulnerable to attack. As such, to ensure the security of critical infrastructures is very important and thus the concept of critical infrastructure protection (CIP) has come. The program to realize the CIP at national level becomes the form of statute in each country. On the other hand, it is also needed to protect each individual critical infrastructure. The objective of this paper is to study on an effort to do so, which can be called the CIP system (CIPS). There could be a variety of ways to design CIPS's. Instead of considering the design of each individual CIPS, a reference model-based approach is taken in this paper. The reference model represents the design of all the CIPS's that have many design elements in common. In addition, the development of the reference model is also carried out using a variety of model diagrams. The modeling language used therein is the systems modeling language (SysML), which was developed and is managed by Object Management Group (OMG) and a de facto standard. Using SysML, the structure and operational concept of the reference model are designed to fulfil the goal of CIPS's, resulting in the block definition and activity diagrams. As a case study, the operational scenario of the nuclear power plant while being attacked by terrorists is studied using the reference model. The effectiveness of the results is also analyzed using multiple analysis models. It is thus expected that the approach taken here has some merits

  20. Evaluation of candidate geomagnetic field models for IGRF-11

    DEFF Research Database (Denmark)

    Finlay, Chris; Maus, S.; Beggan, C. D.

    2010-01-01

    variations between candidates originate. A retrospective analysis of IGRF-10 main field candidates for epoch 2005.0 and predictive secular variation candidates for 2005.0–2010.0 using the new IGRF-11 models as a reference is also reported. The high quality and consistency of main field models derived using...

  1. Collaborative networks: Reference modeling

    NARCIS (Netherlands)

    Camarinha-Matos, L.M.; Afsarmanesh, H.

    2008-01-01

    Collaborative Networks: Reference Modeling works to establish a theoretical foundation for Collaborative Networks. Particular emphasis is put on modeling multiple facets of collaborative networks and establishing a comprehensive modeling framework that captures and structures diverse perspectives of

  2. Mathematical Properties Relevant to Geomagnetic Field Modeling

    DEFF Research Database (Denmark)

    Sabaka, Terence J.; Hulot, Gauthier; Olsen, Nils

    2010-01-01

    be directly measured. In this chapter, the mathematical foundation of global (as opposed to regional) geomagnetic field modeling is reviewed, and the spatial modeling of the field in spherical coordinates is focussed. Time can be dealt with as an independent variable and is not explicitly considered......Geomagnetic field modeling consists in converting large numbers of magnetic observations into a linear combination of elementary mathematical functions that best describes those observations.The set of numerical coefficients defining this linear combination is then what one refers.......The relevant elementary mathematical functions are introduced, their properties are reviewed, and how they can be used to describe the magnetic field in a source-free (such as the Earth’s neutral atmosphere) or source-dense (such as the ionosphere) environment is explained. Completeness and uniqueness...

  3. Mathematical Properties Relevant to Geomagnetic Field Modeling

    DEFF Research Database (Denmark)

    Sabaka, Terence J.; Hulot, Gauthier; Olsen, Nils

    2014-01-01

    be directly measured. In this chapter, the mathematical foundation of global (as opposed to regional) geomagnetic field modeling is reviewed, and the spatial modeling of the field in spherical coordinates is focused. Time can be dealt with as an independent variable and is not explicitly considered......Geomagnetic field modeling consists in converting large numbers of magnetic observations into a linear combination of elementary mathematical functions that best describes those observations. The set of numerical coefficients defining this linear combination is then what one refers....... The relevant elementary mathematical functions are introduced, their properties are reviewed, and how they can be used to describe the magnetic field in a source-free (such as the Earth’s neutral atmosphere) or source-dense (such as the ionosphere) environment is explained. Completeness and uniqueness...

  4. Exactly solvable field-theoretical model with tachyons

    International Nuclear Information System (INIS)

    Barashenkov, I.V.; Getmanov, B.S.; Kovtun, V.E.

    1988-01-01

    Explicit soliton solutions describing the inelastic interaction between sub- and superluminal particles are found within the framework of a new integrable model of relativistic classical field theory. The corresponding energies are nonnegative irrespective of the choice of reference frame

  5. Evaluation of room-scattered neutrons at the JNC Tokai neutron reference field

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Tadayoshi; Tsujimura, Norio [Japan Nuclear Cycle Development Inst., Tokai, Ibaraki (Japan). Tokai Works; Oyanagi, Katsumi [Japan Radiation Engineering Co., Ltd., Hitachi, Ibaraki (Japan)

    2002-09-01

    Neutron reference fields for calibrating neutron-measuring devices in JNC Tokai Works are produced by using radionuclide neutron sources, {sup 241}Am-Be and {sup 252}Cf sources. The reference field for calibration includes scattered neutrons from the material surrounding sources, wall, floor and ceiling of the irradiation room. It is, therefore, necessary to evaluate the scattered neutrons contribution and their energy spectra at reference points. Spectral measurements were performed with a set of Bonner multi-sphere spectrometers and the reference fields were characterized in terms of spectral composition and the fractions of room-scattered neutrons. In addition, two techniques stated in ISO 10647, the shadow-cone method and the polynomial fit method, for correcting the contributions from the room-scattered neutrons to the readings of neutron survey instruments were compared. It was found that the two methods gave an equivalent result within a deviation of 3.3% at a source-to-detector distance from 50cm to 500cm. (author)

  6. Evaluation of room-scattered neutrons at the JNC Tokai neutron reference field

    International Nuclear Information System (INIS)

    Yoshida, Tadayoshi; Tsujimura, Norio

    2002-01-01

    Neutron reference fields for calibrating neutron-measuring devices in JNC Tokai Works are produced by using radionuclide neutron sources, 241 Am-Be and 252 Cf sources. The reference field for calibration includes scattered neutrons from the material surrounding sources, wall, floor and ceiling of the irradiation room. It is, therefore, necessary to evaluate the scattered neutrons contribution and their energy spectra at reference points. Spectral measurements were performed with a set of Bonner multi-sphere spectrometers and the reference fields were characterized in terms of spectral composition and the fractions of room-scattered neutrons. In addition, two techniques stated in ISO 10647, the shadow-cone method and the polynomial fit method, for correcting the contributions from the room-scattered neutrons to the readings of neutron survey instruments were compared. It was found that the two methods gave an equivalent result within a deviation of 3.3% at a source-to-detector distance from 50cm to 500cm. (author)

  7. Extremity ring dosimetry intercomparison in reference and workplace fields

    International Nuclear Information System (INIS)

    Ginjaume, M.; Carinou, E.; Donadille, L.; Jankowski, J.; Rimpler, A.; Sans Merce, M.; Vanhavere, F.; Denoziere, M.; Daures, J.; Bordy, J. M.; Itie, C.; Covens, P.

    2008-01-01

    An intercomparison of ring dosemeters has been organised with the aim of assessing the technical capabilities of available extremity dosemeters and focusing on their performance at clinical workplaces with potentially high extremity doses. Twenty-four services from 16 countries participated in the intercomparison. The dosemeters were exposed to reference photon ( 137 Cs) and beta ( 147 Pm, 85 Kr and 90 Sr/ 90 Y) fields together with fields representing realistic exposure situations in interventional radiology (direct and scattered radiation) and nuclear medicine ( 99m Tc and 18 F). It has been found that most dosemeters provided satisfactory measurements of H p (0.07) for photon radiation, both in reference and realistic fields. However, only four dosemeters fulfilled the established requirements for all radiation qualities. The main difficulties were found for the measurement of low-energy beta radiation. Finally, the results also showed a general under-response of detectors to 18 F, which was attributed to the difficulties of the dosimetric systems to measure the positron contribution to the dose. (authors)

  8. Neutron Reference Benchmark Field Specification: ACRR Free-Field Environment (ACRR-FF-CC-32-CL).

    Energy Technology Data Exchange (ETDEWEB)

    Vega, Richard Manuel [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Parma, Edward J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Griffin, Patrick J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Vehar, David W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-07-01

    This report was put together to support the International Atomic Energy Agency (IAEA) REAL- 2016 activity to validate the dosimetry community’s ability to use a consistent set of activation data and to derive consistent spectral characterizations. The report captures details of integral measurements taken in the Annular Core Research Reactor (ACRR) central cavity free-field reference neutron benchmark field. The field is described and an “a priori” calculated neutron spectrum is reported, based on MCNP6 calculations, and a subject matter expert (SME) based covariance matrix is given for this “a priori” spectrum. The results of 31 integral dosimetry measurements in the neutron field are reported.

  9. Network interconnections: an architectural reference model

    NARCIS (Netherlands)

    Butscher, B.; Lenzini, L.; Morling, R.; Vissers, C.A.; Popescu-Zeletin, R.; van Sinderen, Marten J.; Heger, D.; Krueger, G.; Spaniol, O.; Zorn, W.

    1985-01-01

    One of the major problems in understanding the different approaches in interconnecting networks of different technologies is the lack of reference to a general model. The paper develops the rationales for a reference model of network interconnection and focuses on the architectural implications for

  10. A Comparison Between the OSI Reference Model and the B-ISDN Protocol Reference Model

    DEFF Research Database (Denmark)

    Staalhagen, Lars

    1996-01-01

    This article aims at comparing the Open Systems Interconnection (OSI) Reference Model (RM) and the broadband integrated services digital network (B-ISDN) Protocol Reference Model (PRM). According to the International Telecommunications Union - Telecommunications Sector (ITU-T), the exact...... relationship between the lower layers of the OSI RM and the B-ISDN PRM is for further study. It is therefore the intention of this article to present some views on these relationships which hopefully could facilitate an interconnection between B-ISDN and data networks conforming to the OSI standards....

  11. Adaptive Control with Reference Model Modification

    Science.gov (United States)

    Stepanyan, Vahram; Krishnakumar, Kalmanje

    2012-01-01

    This paper presents a modification of the conventional model reference adaptive control (MRAC) architecture in order to improve transient performance of the input and output signals of uncertain systems. A simple modification of the reference model is proposed by feeding back the tracking error signal. It is shown that the proposed approach guarantees tracking of the given reference command and the reference control signal (one that would be designed if the system were known) not only asymptotically but also in transient. Moreover, it prevents generation of high frequency oscillations, which are unavoidable in conventional MRAC systems for large adaptation rates. The provided design guideline makes it possible to track a reference commands of any magnitude from any initial position without re-tuning. The benefits of the method are demonstrated with a simulation example

  12. Reference models supporting enterprise networks and virtual enterprises

    DEFF Research Database (Denmark)

    Tølle, Martin; Bernus, Peter

    2003-01-01

    This article analyses different types of reference models applicable to support the set up and (re)configuration of Virtual Enterprises (VEs). Reference models are models capturing concepts common to VEs aiming to convert the task of setting up of VE into a configuration task, and hence reducing...... the time needed for VE creation. The reference models are analysed through a mapping onto the Virtual Enterprise Reference Architecture (VERA) based upon GERAM and created in the IMS GLOBEMEN project....

  13. Is the PTW 60019 microDiamond a suitable candidate for small field reference dosimetry?

    Science.gov (United States)

    De Coste, Vanessa; Francescon, Paolo; Marinelli, Marco; Masi, Laura; Paganini, Lucia; Pimpinella, Maria; Prestopino, Giuseppe; Russo, Serenella; Stravato, Antonella; Verona, Claudio; Verona-Rinati, Gianluca

    2017-09-01

    A systematic study of the PTW microDiamond (MD) output factors (OF) is reported, aimed at clarifying its response in small fields and investigating its suitability for small field reference dosimetry. Ten MDs were calibrated under 60Co irradiation. OF measurements were performed in 6 MV photon beams by a CyberKnife M6, a Varian DHX and an Elekta Synergy linacs. Two PTW silicon diodes E (Si-D) were used for comparison. The results obtained by the MDs were evaluated in terms of absorbed dose to water determination in reference conditions and OF measurements, and compared to the results reported in the recent literature. To this purpose, the Monte Carlo (MC) beam-quality correction factor, kQMD , was calculated for the MD, and the small field output correction factors, k{{Qclin},{{Q}msr}}{{fclin},{{f}msr}} , were calculated for both the MD and the Si-D by two different research groups. An empirical function was also derived, providing output correction factors within 0.5% from the MC values calculated for all of the three linacs. A high reproducibility of the dosimetric properties was observed among the ten MDs. The experimental kQMD values are in agreement within 1% with the MC calculated ones. Output correction factors within  +0.7% and  -1.4% were obtained down to field sizes as narrow as 5 mm. The resulting MD and Si-D field factors are in agreement within 0.2% in the case of CyberKnife measurements and 1.6% in the other cases. This latter higher spread of the data was demonstrated to be due to a lower reproducibility of small beam sizes defined by jaws or multi leaf collimators. The results of the present study demonstrate the reproducibility of the MD response and provide a validation of the MC modelling of this device. In principle, accurate reference dosimetry is thus feasible by using the microDiamond dosimeter for field sizes down to 5 mm.

  14. Predictor-Based Model Reference Adaptive Control

    Science.gov (United States)

    Lavretsky, Eugene; Gadient, Ross; Gregory, Irene M.

    2010-01-01

    This paper is devoted to the design and analysis of a predictor-based model reference adaptive control. Stable adaptive laws are derived using Lyapunov framework. The proposed architecture is compared with the now classical model reference adaptive control. A simulation example is presented in which numerical evidence indicates that the proposed controller yields improved transient characteristics.

  15. Top-Down Enterprise Application Integration with Reference Models

    Directory of Open Access Journals (Sweden)

    Willem-Jan van den Heuvel

    2000-11-01

    Full Text Available For Enterprise Resource Planning (ERP systems such as SAP R/3 or IBM SanFrancisco, the tailoring of reference models for customizing the ERP systems to specific organizational contexts is an established approach. In this paper, we present a methodology that uses such reference models as a starting point for a top-down integration of enterprise applications. The re-engineered models of legacy systems are individually linked via cross-mapping specifications to the forward-engineered reference model's specification. The actual linking of reference and legacy models is done with a methodology for connecting (new business objects with (old legacy systems.

  16. The Egyptian geomagnetic reference field to the Epoch, 2010.0

    Science.gov (United States)

    Deebes, H. A.; Abd Elaal, E. M.; Arafa, T.; Lethy, A.; El Emam, A.; Ghamry, E.; Odah, H.

    2017-06-01

    The present work is a compilation of two tasks within the frame of the project ;Geomagnetic Survey & Detailed Geomagnetic Measurements within the Egyptian Territory; funded by the ;Science and Technology Development Fund agency (STDF);. The National Research Institute of Astronomy and Geophysics (NRIAG), has conducted a new extensive land geomagnetic survey that covers the whole Egyptian territory. The field measurements have been done at 3212 points along all the asphalted roads, defined tracks, and ill-defined tracks in Egypt; with total length of 11,586 km. In the present work, the measurements cover for the first time new areas as: the southern eastern borders of Egypt including Halayeb and Shlatin, the Quattara depresion in the western desert, and the new roads between Farafra and Baharia oasis. Also marine geomagnetic survey have been applied for the first time in Naser lake. Misallat and Abu-Simble geomagnetic observatories have been used to reduce the field data to the Epoch 2010. During the field measurements, whenever possible, the old stations occupied by the previous observers have been re-occupied to determine the secular variations at these points. The geomagnetic anomaly maps, the normal geomagnetic field maps with their corresponding secular variation maps, the normal geomagnetic field equations of the geomagnetic elements (EGRF) and their corresponding secular variations equations, are outlined. The anomalous sites, as discovered from the anomaly maps are, only, mentioned. In addition, a correlation between the International Geomagnetic Reference Field (IGRF) 2010.0 and the Egyptian Geomagnetic Reference Field (EGRF) 2010 is indicated.

  17. Reference model for apparel product development

    Directory of Open Access Journals (Sweden)

    Isabel Cristina Moretti

    2017-03-01

    Full Text Available The purpose of this paper was to develop a reference model for the implementation of the process of product development (PDP for apparel. The tool was developed through an interactive process of comparison between theoretical. Managers in companies and professionals working in this market can utilize the reference model as a source for the organization and improvement of the PDP for apparel and the universities as a reference source for systematized teaching of this process. This model represents the first comprehensive attempt to develop an instrument at a detailed level (macro phases, phases, activities, inputs and outputs at each stage and at the gates to systematize the PDP process for fashion products and to consider its particularities.

  18. Geomagnetic field models for satellite angular motion studies

    Science.gov (United States)

    Ovchinnikov, M. Yu.; Penkov, V. I.; Roldugin, D. S.; Pichuzhkina, A. V.

    2018-03-01

    Four geomagnetic field models are discussed: IGRF, inclined, direct and simplified dipoles. Geomagnetic induction vector expressions are provided in different reference frames. Induction vector behavior is compared for different models. Models applicability for the analysis of satellite motion is studied from theoretical and engineering perspectives. Relevant satellite dynamics analysis cases using analytical and numerical techniques are provided. These cases demonstrate the benefit of a certain model for a specific dynamics study. Recommendations for models usage are summarized in the end.

  19. Evaluation of candidate geomagnetic field models for IGRF-12

    OpenAIRE

    Erwan Thébault; Christopher C. Finlay; Patrick Alken; Ciaran D. Beggan; Elisabeth Canet; Arnaud Chulliat; Benoit Langlais; V. Lesur; Frank J. Lowes; Chandrasekharan Manoj; Martin Rother; Reyko Schachtschneider

    2015-01-01

    Background: The 12th revision of the International Geomagnetic Reference Field (IGRF) was issued in December 2014 by the International Association of Geomagnetism and Aeronomy (IAGA) Division V Working Group V-MOD (http://www.ngdc.noaa.gov/IAGA/vmod/igrf.html). This revision comprises new spherical harmonic main field models for epochs 2010.0 (DGRF-2010) and 2015.0 (IGRF-2015) and predictive linear secular variation for the interval 2015.0-2020.0 (SV-2010-2015). Findings: The models were deri...

  20. Verification of SAP reference models

    NARCIS (Netherlands)

    Dongen, van B.F.; Jansen-Vullers, M.H.; Aalst, van der W.M.P.; Benatallah, B.; Casati, F.

    2005-01-01

    To configure a process-aware information system (e.g., a workflow system, an ERP system), a business model needs to be transformed into an executable process model. Due to similarities in these transformations for different companies, databases with reference models, such as ARIS for MySAP, have

  1. The Use of Reference Models in Business Process Renovation

    Directory of Open Access Journals (Sweden)

    Dejan Pajk

    2010-01-01

    Full Text Available Enterprise resource planning (ERP systems are often used by companies to automate and enhance their busi- ness processes. The capabilities of ERP systems can be described by best-practice reference models. The purpose of the article is to demonstrate the business process renovation approach with the use of reference models. Although the use of reference models brings many positive effects for business, they are still rarely used in Slovenian small and medium-sized compa- nies. The reasons for this may be found in the reference models themselves as well as in project implementation methodologies. In the article a reference model based on Microsoft Dynamics NAV is suggested. The reference model is designed using upgraded BPMN notation with additional business objects, which help to describe the models in more detail.

  2. The use of the empirical mode decomposition for the identification of mean field aligned reference frames

    Directory of Open Access Journals (Sweden)

    Mauro Regi

    2017-01-01

    Full Text Available The magnetic field satellite data are usually referred to geocentric coordinate reference frame. Conversely, the magnetohydrodynamic waves modes in magnetized plasma depend on the ambient magnetic field, and is then useful to rotate the magnetic field measurements into the mean field aligned (MFA coordinate system. This reference frame is useful to study the ultra low frequency magnetic field variations along the direction of the mean field and perpendicularly to it. In order to identify the mean magnetic field the classical moving average (MAVG approach is usually adopted but, under particular conditions, this procedure induces undesired features, such as spectral alteration in the rotated components. We discuss these aspects promoting an alternative and more efficient method for mean field aligned projection, based on the empirical mode decomposition (EMD.

  3. Topology of magnetic fields in particle physics, implications on the quark model

    Energy Technology Data Exchange (ETDEWEB)

    Jehle, H.

    1977-01-01

    The flux-loop model of quarks is considered covering electomagnetic gauge invariance, flux quantization, topological conditions for the magnetic field, the extended source model, the electric field, linkage of loop forms, topology and motion of flux loop forms, coalial loops of hadrons having weak interactions, magnetic moments of hadrons, strong interactions, some remarks about string models, and the implications of he topological quark model on the ground and excited states of mesons. 80 references. (JFP)

  4. Different resistance patterns of reference and field strains of Brucella abortus

    Directory of Open Access Journals (Sweden)

    Karina L. Miranda

    2015-03-01

    Full Text Available The aim of this study was to evaluate the growth of the B. abortus reference strains and field isolates on media containing different inhibitor agents. Reference strains were seeded on tryptose agar containing: i-erythritol (1.0 mg/mL, fuchsin (20 μg/mL and 80 μg/mL, thionin (2.5 μg/mL and 10 μg/mL, rifampicin (200 μg/mL and safranin O (200 μg/mL. Field isolates were tested only on media containing i-erythritol, rifampicin and thionin. Furthermore, each suspension was also inoculated on tryptose agar incubated in air, to test its ability to grow without CO2. Sensitivity to fuchsin was similar among reference strains evaluated. Growth of S19, 544 and 2308 but not RB51 were inhibited on media containing rifampicin. Medium with safranin O showed no inhibition for RB51, 544 and 2308, but it partially inhibited the S19 growth as well as medium containing i-erythritol. Treatment/control growth ratio for 2308 on tryptose agar containing thionin (2.5 μg/mL was approximatelly 1.0, whereas S19 and RB51 showed 0.85 and 0.89 ratios, respectively. Growth of 544, S19 and RB51 but not 2308 was completely inhibited on medium with thionin (10 μg/mL. All field strains grew on medium containing i-erythritol, but were completelly inhibited by rifampicin. With exception of A1 (B. abortus biovar 3 all field isolates grew on medium with thionin, although some strains showed a treatment/control growth ratio of 0.75–0.80 (10 μg/mL. These results showed that tryptose agar with thionin, i-erythritol or rifampicin could be useful for differentiating vaccine, challenge and field strains of B. abortus.

  5. A New Model of Jupiter's Magnetic Field from Juno's First Nine Orbits

    DEFF Research Database (Denmark)

    Connerney, J. E. P.; Kotsiaros, S.; Oliversen, R. J.

    2018-01-01

    A spherical harmonic model of the magnetic field of Jupiter is obtained from vector magnetic field observations acquired by the Juno spacecraft during its first nine polar orbits about the planet. Observations acquired during eight of these orbits provide the first truly global coverage of Jupiter......'s magnetic field with a coarse longitudinal separation of ~45° between perijoves. The magnetic field is represented with a degree 20 spherical harmonic model for the planetary (“internal”) field, combined with a simple model of the magnetodisc for the field (“external”) due to distributed magnetospheric...... currents. Partial solution of the underdetermined inverse problem using generalized inverse techniques yields a model (“Juno Reference Model through Perijove 9”) of the planetary magnetic field with spherical harmonic coefficients well determined through degree and order 10, providing the first detailed...

  6. A New Model of Jupiter's Magnetic Field From Juno's First Nine Orbits

    Science.gov (United States)

    Connerney, J. E. P.; Kotsiaros, S.; Oliversen, R. J.; Espley, J. R.; Joergensen, J. L.; Joergensen, P. S.; Merayo, J. M. G.; Herceg, M.; Bloxham, J.; Moore, K. M.; Bolton, S. J.; Levin, S. M.

    2018-03-01

    A spherical harmonic model of the magnetic field of Jupiter is obtained from vector magnetic field observations acquired by the Juno spacecraft during its first nine polar orbits about the planet. Observations acquired during eight of these orbits provide the first truly global coverage of Jupiter's magnetic field with a coarse longitudinal separation of 45° between perijoves. The magnetic field is represented with a degree 20 spherical harmonic model for the planetary ("internal") field, combined with a simple model of the magnetodisc for the field ("external") due to distributed magnetospheric currents. Partial solution of the underdetermined inverse problem using generalized inverse techniques yields a model ("Juno Reference Model through Perijove 9") of the planetary magnetic field with spherical harmonic coefficients well determined through degree and order 10, providing the first detailed view of a planetary dynamo beyond Earth.

  7. Errors in the SAP reference model

    NARCIS (Netherlands)

    Mendling, J.; Aalst, van der W.M.P.; Dongen, van B.F.; Verbeek, H.M.W.

    2006-01-01

    The SAP Reference Model is a set of information models that is utilized to guide the configuration of SAP systems. A big part of these models are business process models represented in the Eventdriven Process Chains (EPC) notation. These EPC models provide a easy to comprehend overview of SAP

  8. Efficient implementation of three-dimensional reference interaction site model self-consistent-field method: application to solvatochromic shift calculations.

    Science.gov (United States)

    Minezawa, Noriyuki; Kato, Shigeki

    2007-02-07

    The authors present an implementation of the three-dimensional reference interaction site model self-consistent-field (3D-RISM-SCF) method. First, they introduce a robust and efficient algorithm for solving the 3D-RISM equation. The algorithm is a hybrid of the Newton-Raphson and Picard methods. The Jacobian matrix is analytically expressed in a computationally useful form. Second, they discuss the solute-solvent electrostatic interaction. For the solute to solvent route, the electrostatic potential (ESP) map on a 3D grid is constructed directly from the electron density. The charge fitting procedure is not required to determine the ESP. For the solvent to solute route, the ESP acting on the solute molecule is derived from the solvent charge distribution obtained by solving the 3D-RISM equation. Matrix elements of the solute-solvent interaction are evaluated by the direct numerical integration. A remarkable reduction in the computational time is observed in both routes. Finally, the authors implement the first derivatives of the free energy with respect to the solute nuclear coordinates. They apply the present method to "solute" water and formaldehyde in aqueous solvent using the simple point charge model, and the results are compared with those from other methods: the six-dimensional molecular Ornstein-Zernike SCF, the one-dimensional site-site RISM-SCF, and the polarizable continuum model. The authors also calculate the solvatochromic shifts of acetone, benzonitrile, and nitrobenzene using the present method and compare them with the experimental and other theoretical results.

  9. A New Model of Jupiter's Magnetic Field from Juno's First Nine Orbits

    DEFF Research Database (Denmark)

    Connerney, J. E. P.; Kotsiaros, S.; Oliversen, R. J.

    2018-01-01

    A spherical harmonic model of the magnetic field of Jupiter is obtained from vector magnetic field observations acquired by the Juno spacecraft during its first nine polar orbits about the planet. Observations acquired during eight of these orbits provide the first truly global coverage of Jupiter...... currents. Partial solution of the underdetermined inverse problem using generalized inverse techniques yields a model (“Juno Reference Model through Perijove 9”) of the planetary magnetic field with spherical harmonic coefficients well determined through degree and order 10, providing the first detailed...

  10. A physical data model for fields and agents

    Science.gov (United States)

    de Jong, Kor; de Bakker, Merijn; Karssenberg, Derek

    2016-04-01

    models and the raster data model, among many other data models. Our physical data model is capable of storing a first set of kinds of data, like omnipresent scalars, mobile spatio-temporal points and property values, and spatio-temporal rasters. With our poster we will provide an overview of the physical data model expressed in HDF5 and show examples of how it can be used to capture both object- and field-based information. References De Bakker, M, K. de Jong, D. Karssenberg. 2016. A conceptual data model and language for fields and agents. European Geosciences Union, EGU General Assembly, 2016, Vienna.

  11. Consistent Feature Extraction From Vector Fields: Combinatorial Representations and Analysis Under Local Reference Frames

    Energy Technology Data Exchange (ETDEWEB)

    Bhatia, Harsh [Univ. of Utah, Salt Lake City, UT (United States)

    2015-05-01

    This dissertation presents research on addressing some of the contemporary challenges in the analysis of vector fields—an important type of scientific data useful for representing a multitude of physical phenomena, such as wind flow and ocean currents. In particular, new theories and computational frameworks to enable consistent feature extraction from vector fields are presented. One of the most fundamental challenges in the analysis of vector fields is that their features are defined with respect to reference frames. Unfortunately, there is no single “correct” reference frame for analysis, and an unsuitable frame may cause features of interest to remain undetected, thus creating serious physical consequences. This work develops new reference frames that enable extraction of localized features that other techniques and frames fail to detect. As a result, these reference frames objectify the notion of “correctness” of features for certain goals by revealing the phenomena of importance from the underlying data. An important consequence of using these local frames is that the analysis of unsteady (time-varying) vector fields can be reduced to the analysis of sequences of steady (timeindependent) vector fields, which can be performed using simpler and scalable techniques that allow better data management by accessing the data on a per-time-step basis. Nevertheless, the state-of-the-art analysis of steady vector fields is not robust, as most techniques are numerical in nature. The residing numerical errors can violate consistency with the underlying theory by breaching important fundamental laws, which may lead to serious physical consequences. This dissertation considers consistency as the most fundamental characteristic of computational analysis that must always be preserved, and presents a new discrete theory that uses combinatorial representations and algorithms to provide consistency guarantees during vector field analysis along with the uncertainty

  12. Automated particulate sampler field test model operations guide

    Energy Technology Data Exchange (ETDEWEB)

    Bowyer, S.M.; Miley, H.S.

    1996-10-01

    The Automated Particulate Sampler Field Test Model Operations Guide is a collection of documents which provides a complete picture of the Automated Particulate Sampler (APS) and the Field Test in which it was evaluated. The Pacific Northwest National Laboratory (PNNL) Automated Particulate Sampler was developed for the purpose of radionuclide particulate monitoring for use under the Comprehensive Test Ban Treaty (CTBT). Its design was directed by anticipated requirements of small size, low power consumption, low noise level, fully automatic operation, and most predominantly the sensitivity requirements of the Conference on Disarmament Working Paper 224 (CDWP224). This guide is intended to serve as both a reference document for the APS and to provide detailed instructions on how to operate the sampler. This document provides a complete description of the APS Field Test Model and all the activity related to its evaluation and progression.

  13. Delusions of reference: a new theoretical model.

    Science.gov (United States)

    Startup, Mike; Bucci, Sandra; Langdon, Robyn

    2009-03-01

    Although delusions of reference are one of the most common psychotic symptoms, they have been the focus of little research, possibly because they have been considered to be integral to persecutory delusions. Evidence has now emerged that there are two kinds of delusion of reference. One of these, referential delusions of communication, which involves beliefs that others are communicating in subtle, nonverbal ways, is the focus of this paper. We present a new model designed to account for the four crucial aspects of the phenomenology of these delusions: (1) that neutral stimuli are experienced as having personal significance; (2) that the neutral stimuli are experienced as communicating a message nonverbally; (3) that the content of the message concerns the self; (4) that the experience of a self-referent communication is believed rather than being dismissed as implausible. We used PsycINFO and Scopus, using the term "delusion* of reference", to search for publications with a bearing on our model. The amount of research we found that was designed to test aspects of this model is small but other published research appears to provide some support for its various steps. Much of this research was not explicitly intended to provide an account of delusions of reference but its relevance nevertheless seems clear. There is preliminary support for the plausibility of our model but much additional research is needed. We conclude by summarising what we consider to be the main desiderata.

  14. A Reference Field for GCR Simulation and an LET-Based Implementation at NSRL

    Science.gov (United States)

    Slaba, Tony C.; Blattnig, Steve R.; Walker, Steven A.; Norbury, John W.

    2015-01-01

    Exposure to galactic cosmic rays (GCR) on long duration deep space missions presents a serious health risk to astronauts, with large uncertainties connected to the biological response. In order to reduce the uncertainties and gain understanding about the basic mechanisms through which space radiation initiates cancer and other endpoints, radiobiology experiments are performed. Some of the accelerator facilities supporting such experiments have matured to a point where simulating the broad range of particles and energies characteristic of the GCR environment in a single experiment is feasible from a technology, usage, and cost perspective. In this work, several aspects of simulating the GCR environment in the laboratory are discussed. First, comparisons are made between direct simulation of the external, free space GCR field and simulation of the induced tissue field behind shielding. It is found that upper energy constraints at the NASA Space Radiation Laboratory (NSRL) limit the ability to simulate the external, free space field directly (i.e. shielding placed in the beam line in front of a biological target and exposed to a free space spectrum). Second, variation in the induced tissue field associated with shielding configuration and solar activity is addressed. It is found that the observed variation is within physical uncertainties, allowing a single reference field for deep space missions to be defined. Third, an approach for simulating the reference field at NSRL is presented. The approach allows for the linear energy transfer (LET) spectrum of the reference field to be approximately represented with discrete ion and energy beams and implicitly maintains a reasonably accurate charge spectrum (or, average quality factor). Drawbacks of the proposed methodology are discussed and weighed against alternative simulation strategies. The neutron component and track structure characteristics of the proposed strategy are discussed in this context.

  15. A Reference Model for Virtual Machine Launching Overhead

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Hao; Ren, Shangping; Garzoglio, Gabriele; Timm, Steven; Bernabeu, Gerard; Chadwick, Keith; Noh, Seo-Young

    2016-07-01

    Cloud bursting is one of the key research topics in the cloud computing communities. A well designed cloud bursting module enables private clouds to automatically launch virtual machines (VMs) to public clouds when more resources are needed. One of the main challenges in developing a cloud bursting module is to decide when and where to launch a VM so that all resources are most effectively and efficiently utilized and the system performance is optimized. However, based on system operational data obtained from FermiCloud, a private cloud developed by the Fermi National Accelerator Laboratory for scientific workflows, the VM launching overhead is not a constant. It varies with physical resource utilization, such as CPU and I/O device utilizations, at the time when a VM is launched. Hence, to make judicious decisions as to when and where a VM should be launched, a VM launching overhead reference model is needed. In this paper, we first develop a VM launching overhead reference model based on operational data we have obtained on FermiCloud. Second, we apply the developed reference model on FermiCloud and compare calculated VM launching overhead values based on the model with measured overhead values on FermiCloud. Our empirical results on FermiCloud indicate that the developed reference model is accurate. We believe, with the guidance of the developed reference model, efficient resource allocation algorithms can be developed for cloud bursting process to minimize the operational cost and resource waste.

  16. Establishing a Business Process Reference Model for Universities

    KAUST Repository

    Svensson, Carsten

    2012-09-01

    Modern universities are by any standard complex organizations that, from an IT perspective, present a number of unique challenges. This paper will propose establishing a business process reference framework. The benefit to the users would be a better understanding of the system landscape, business process enablement, collection of performance data and systematic reuse of existing community experience and knowledge. For these reasons reference models such as the SCOR (Supply Chain Operations Reference), DCOR (Design Chain Operations Reference) and ITIL (Information Technology Infrastructure Library) have gained popularity among organizations in both the private and public sectors. We speculate that this success can be replicated in a university setting. Furthermore the paper will outline how the research group suggests moving ahead with the research which will lead to a reference model.

  17. Reference radiation fields - Simulated workplace neutron fields - Part 2: Calibration fundamentals related to the basic quantities

    International Nuclear Information System (INIS)

    2008-01-01

    ISO 8529-1, ISO 8529-2 and ISO 8529-3, deal with the production, characterization and use of neutron fields for the calibration of personal dosimeters and area survey meters. These International Standards describe reference radiations with neutron energy spectra that are well defined and well suited for use in the calibration laboratory. However, the neutron spectra commonly encountered in routine radiation protection situations are, in many cases, quite different from those produced by the sources specified in the International Standards. Since personal neutron dosimeters, and to a lesser extent survey meters, are generally quite energy dependent in their dose equivalent response, it might not be possible to achieve an appropriate calibration for a device that is used in a workplace where the neutron energy spectrum and angular distribution differ significantly from those of the reference radiation used for calibration. ISO 8529-1 describes four radionuclide based neutron reference radiations in detail. This part of ISO 12789 includes the specification of neutron reference radiations that were developed to closely resemble radiation that is encountered in practice

  18. Assessment of a dynamic reference material for calibration of full-field measurement systems

    Science.gov (United States)

    Hack, Erwin; Feligiotti, Mara; Davighi, Andrea; Whelan, Maurice; Wang, Weizhuo V.; Patterson, Eann A.

    2012-10-01

    For holography and speckle interferometry the calibration of the sensitivity is a must, because illumination and observation directions vary across the field of view. A numerical estimate or a static calibration using rigid body motions is standard, and reference materials exist for static strain calibration. Recently, reference materials for the dynamic calibration of optical instruments of displacement and strain measurement were designed and prototypes were manufactured in the European FP7 project ADVISE. We review the properties of the reference material and the concept of traceability for the field of displacement values by using a calibrated single point transducer. The mode shape is assessed using out-of-plane DSPI, Finite Element Analysis as well as analytic solutions of the plate vibration. We present measurements using stroboscopic DSPI on the reference material under acoustic excitation and compare the measured mode shapes to the ones predicted by FE analysis. We apply different comparison methodologies based on point-by-point deviations and on decomposition of the mode shapes into a set of orthogonal basis functions. The latter method is well suited to assess stability and reproducibility of a mode shape. Finally, the deviations are used to estimate the reference material uncertainty which is an essential parameter for determining the calibration uncertainty. Uncertainty contributions of the DSPI set-up are taken into account. To conclude, the application area and limitations of the reference material are discussed.

  19. Virtual Reference, Real Money: Modeling Costs in Virtual Reference Services

    Science.gov (United States)

    Eakin, Lori; Pomerantz, Jeffrey

    2009-01-01

    Libraries nationwide are in yet another phase of belt tightening. Without an understanding of the economic factors that influence library operations, however, controlling costs and performing cost-benefit analyses on services is difficult. This paper describes a project to develop a cost model for collaborative virtual reference services. This…

  20. Domino model for geomagnetic field reversals.

    Science.gov (United States)

    Mori, N; Schmitt, D; Wicht, J; Ferriz-Mas, A; Mouri, H; Nakamichi, A; Morikawa, M

    2013-01-01

    We solve the equations of motion of a one-dimensional planar Heisenberg (or Vaks-Larkin) model consisting of a system of interacting macrospins aligned along a ring. Each spin has unit length and is described by its angle with respect to the rotational axis. The orientation of the spins can vary in time due to spin-spin interaction and random forcing. We statistically describe the behavior of the sum of all spins for different parameters. The term "domino model" in the title refers to the interaction among the spins. We compare the model results with geomagnetic field reversals and dynamo simulations and find strikingly similar behavior. The aggregate of all spins keeps the same direction for a long time and, once in a while, begins flipping to change the orientation by almost 180 degrees (mimicking a geomagnetic reversal) or to move back to the original direction (mimicking an excursion). Most of the time the spins are aligned or antialigned and deviate only slightly with respect to the rotational axis (mimicking the secular variation of the geomagnetic pole with respect to the geographic pole). Reversals are fast compared to the times in between and they occur at random times, both in the model and in the case of the Earth's magnetic field.

  1. Evaluation of candidate geomagnetic field models for IGRF-12

    DEFF Research Database (Denmark)

    Thébault, Erwan; Finlay, Chris; Alken, Patrick

    2015-01-01

    Background: The 12th revision of the International Geomagnetic Reference Field (IGRF) was issued in December 2014 by the International Association of Geomagnetism and Aeronomy (IAGA) Division V Working Group V-MOD (http://www.ngdc.noaa.gov/IAGA/vmod/igrf.html). This revision comprises new spherical...... by the British Geological Survey (UK), DTU Space (Denmark), ISTerre (France), IZMIRAN (Russia), NOAA/NGDC (USA), GFZ Potsdam (Germany), NASA/GSFC (USA), IPGP (France), LPG Nantes (France), and ETH Zurich (Switzerland). Each candidate model was carefully evaluated and compared to all other models and a mean model...

  2. Strategies to evaluate goodness of reference strips for in-season, field scale, irrigated corn nitrogen sufficiency

    Science.gov (United States)

    The nitrogen (N) sufficiency approach to assess plant N status for in-season N management requires a non-N-limiting reference to make N recommendations. Use of reference strips in fields with spatially variable soils and the impact this variability has within N enriched reference strips are not we...

  3. Petroleum Refinery Jobs and Economic Development Impact (JEDI) Model User Reference Guide

    Energy Technology Data Exchange (ETDEWEB)

    Goldberg, Marshall [MRG and Associates, Nevada City, CA (United States)

    2013-12-31

    The Jobs and Economic Development Impact (JEDI) models, developed through the National Renewable Energy Laboratory (NREL), are user-friendly tools utilized to estimate the economic impacts at the local level of constructing and operating fuel and power generation projects for a range of conventional and renewable energy technologies. The JEDI Petroleum Refinery Model User Reference Guide was developed to assist users in employing and understanding the model. This guide provides information on the model's underlying methodology, as well as the parameters and references used to develop the cost data utilized in the model. This guide also provides basic instruction on model add-in features, operation of the model, and a discussion of how the results should be interpreted. Based on project-specific inputs from the user, the model estimates job creation, earning and output (total economic activity) for a given petroleum refinery. This includes the direct, indirect and induced economic impacts to the local economy associated with the refinery's construction and operation phases. Project cost and job data used in the model are derived from the most current cost estimations available. Local direct and indirect economic impacts are estimated using economic multipliers derived from IMPLAN software. By determining the regional economic impacts and job creation for a proposed refinery, the JEDI Petroleum Refinery model can be used to field questions about the added value refineries may bring to the local community.

  4. Time-dependent density functional theory (TD-DFT) coupled with reference interaction site model self-consistent field explicitly including spatial electron density distribution (RISM-SCF-SEDD)

    Energy Technology Data Exchange (ETDEWEB)

    Yokogawa, D., E-mail: d.yokogawa@chem.nagoya-u.ac.jp [Department of Chemistry, Graduate School of Science, Nagoya University, Chikusa, Nagoya 464-8602 (Japan); Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Chikusa, Nagoya 464-8602 (Japan)

    2016-09-07

    Theoretical approach to design bright bio-imaging molecules is one of the most progressing ones. However, because of the system size and computational accuracy, the number of theoretical studies is limited to our knowledge. To overcome the difficulties, we developed a new method based on reference interaction site model self-consistent field explicitly including spatial electron density distribution and time-dependent density functional theory. We applied it to the calculation of indole and 5-cyanoindole at ground and excited states in gas and solution phases. The changes in the optimized geometries were clearly explained with resonance structures and the Stokes shift was correctly reproduced.

  5. Reference Inflow Characterization for River Resource Reference Model (RM2)

    Energy Technology Data Exchange (ETDEWEB)

    Neary, Vincent S [ORNL

    2011-12-01

    Sandia National Laboratory (SNL) is leading an effort to develop reference models for marine and hydrokinetic technologies and wave and current energy resources. This effort will allow the refinement of technology design tools, accurate estimates of a baseline levelized cost of energy (LCoE), and the identification of the main cost drivers that need to be addressed to achieve a competitive LCoE. As part of this effort, Oak Ridge National Laboratory was charged with examining and reporting reference river inflow characteristics for reference model 2 (RM2). Published turbulent flow data from large rivers, a water supply canal and laboratory flumes, are reviewed to determine the range of velocities, turbulence intensities and turbulent stresses acting on hydrokinetic technologies, and also to evaluate the validity of classical models that describe the depth variation of the time-mean velocity and turbulent normal Reynolds stresses. The classical models are found to generally perform well in describing river inflow characteristics. A potential challenge in river inflow characterization, however, is the high variability of depth and flow over the design life of a hydrokinetic device. This variation can have significant effects on the inflow mean velocity and turbulence intensity experienced by stationary and bottom mounted hydrokinetic energy conversion devices, which requires further investigation, but are expected to have minimal effects on surface mounted devices like the vertical axis turbine device designed for RM2. A simple methodology for obtaining an approximate inflow characterization for surface deployed devices is developed using the relation umax=(7/6)V where V is the bulk velocity and umax is assumed to be the near-surface velocity. The application of this expression is recommended for deriving the local inflow velocity acting on the energy extraction planes of the RM2 vertical axis rotors, where V=Q/A can be calculated given a USGS gage flow time

  6. Nuclide release calculation in the near-field of a reference HLW repository

    International Nuclear Information System (INIS)

    Lee, Youn Myoung; Hwang, Yong Soo; Kang, Chul Hyung

    2004-01-01

    The HLW-relevant R and D program for disposal of high-level radioactive waste has been carried out at Korea Atomic Energy Research Institute (KAERI) since early 1997 in order to develop a conceptual Korea Reference Repository System for direct disposal of nuclear spent fuel by the end of 2007. A preliminary reference geologic repository concept considering such established criteria and requirements as waste and generic site characteristics in Korea was roughly envisaged in 2003 focusing on the near-field components of the repository system. According to above basic repository concept, which is similar to that of Swedish KBS-3 repository, the spent fuel is first encapsulated in corrosion resistant canisters, even though the material has not yet been determined, and then emplaced into the deposition holes surrounded by high density bentonite clay in tunnels constructed at a depth of about 500 m in a stable plutonic rock body. Not only to demonstrate how much a reference repository is safe in the generic point of view with several possible scenarios and cases associated with a preliminary repository concept by conducting calculations for nuclide release and transport in the near-field components of the repository, even though enough information has not been available that much yet, but also to show a methodology by which a generic safety assessment could be performed for further development of Korea reference repository concept, nuclide release calculation study strongly seems to be necessary

  7. A conceptual data model and modelling language for fields and agents

    Science.gov (United States)

    de Bakker, Merijn; de Jong, Kor; Schmitz, Oliver; Karssenberg, Derek

    2016-04-01

    extent. Properties sharing the same domain are grouped into a property set. The conceptual data model is translated into a physical data model in de Jong et al. (2016, presented in the same session). We have designed a modelling language that allows domain specialists to build models without the programming efforts required by many programming environments. The language is based on the ideas of map algebra. We have defined data types that are associated with a phenomenon. These data types determine the behavior of the language when used as arguments in operations. The result is a concise language in which fields and agents can be combined in operations. We test the language in a case study modelling exposure to air pollution of commuting children. References De Jong, K, M. de Bakker, D. Karssenberg. 2016. A physical data model for fields and agents. European Geosciences Union, EGU General Assembly, 2016, Vienna.

  8. Improved modeling techniques for turbomachinery flow fields

    Energy Technology Data Exchange (ETDEWEB)

    Lakshminarayana, B. [Pennsylvania State Univ., University Park, PA (United States); Fagan, J.R. Jr. [Allison Engine Company, Indianapolis, IN (United States)

    1995-10-01

    This program has the objective of developing an improved methodology for modeling turbomachinery flow fields, including the prediction of losses and efficiency. Specifically, the program addresses the treatment of the mixing stress tensor terms attributed to deterministic flow field mechanisms required in steady-state Computational Fluid Dynamic (CFD) models for turbo-machinery flow fields. These mixing stress tensors arise due to spatial and temporal fluctuations (in an absolute frame of reference) caused by rotor-stator interaction due to various blade rows and by blade-to-blade variation of flow properties. These tasks include the acquisition of previously unavailable experimental data in a high-speed turbomachinery environment, the use of advanced techniques to analyze the data, and the development of a methodology to treat the deterministic component of the mixing stress tensor. Penn State will lead the effort to make direct measurements of the momentum and thermal mixing stress tensors in high-speed multistage compressor flow field in the turbomachinery laboratory at Penn State. They will also process the data by both conventional and conditional spectrum analysis to derive momentum and thermal mixing stress tensors due to blade-to-blade periodic and aperiodic components, revolution periodic and aperiodic components arising from various blade rows and non-deterministic (which includes random components) correlations. The modeling results from this program will be publicly available and generally applicable to steady-state Navier-Stokes solvers used for turbomachinery component (compressor or turbine) flow field predictions. These models will lead to improved methodology, including loss and efficiency prediction, for the design of high-efficiency turbomachinery and drastically reduce the time required for the design and development cycle of turbomachinery.

  9. Forecasting the Reference Evapotranspiration Using Time Series Model

    Directory of Open Access Journals (Sweden)

    H. Zare Abyaneh

    2016-10-01

    Full Text Available Introduction: Reference evapotranspiration is one of the most important factors in irrigation timing and field management. Moreover, reference evapotranspiration forecasting can play a vital role in future developments. Therefore in this study, the seasonal autoregressive integrated moving average (ARIMA model was used to forecast the reference evapotranspiration time series in the Esfahan, Semnan, Shiraz, Kerman, and Yazd synoptic stations. Materials and Methods: In the present study in all stations (characteristics of the synoptic stations are given in Table 1, the meteorological data, including mean, maximum and minimum air temperature, relative humidity, dry-and wet-bulb temperature, dew-point temperature, wind speed, precipitation, air vapor pressure and sunshine hours were collected from the Islamic Republic of Iran Meteorological Organization (IRIMO for the 41 years from 1965 to 2005. The FAO Penman-Monteith equation was used to calculate the monthly reference evapotranspiration in the five synoptic stations and the evapotranspiration time series were formed. The unit root test was used to identify whether the time series was stationary, then using the Box-Jenkins method, seasonal ARIMA models were applied to the sample data. Table 1. The geographical location and climate conditions of the synoptic stations Station\tGeographical location\tAltitude (m\tMean air temperature (°C\tMean precipitation (mm\tClimate, according to the De Martonne index classification Longitude (E\tLatitude (N Annual\tMin. and Max. Esfahan\t51° 40'\t32° 37'\t1550.4\t16.36\t9.4-23.3\t122\tArid Semnan\t53° 33'\t35° 35'\t1130.8\t18.0\t12.4-23.8\t140\tArid Shiraz\t52° 36'\t29° 32'\t1484\t18.0\t10.2-25.9\t324\tSemi-arid Kerman\t56° 58'\t30° 15'\t1753.8\t15.6\t6.7-24.6\t142\tArid Yazd\t54° 17'\t31° 54'\t1237.2\t19.2\t11.8-26.0\t61\tArid Results and Discussion: The monthly meteorological data were used as input for the Ref-ET software and monthly reference

  10. Charging of mobile services by mobile payment reference model

    OpenAIRE

    Pousttchi, Key; Wiedemann, Dietmar Georg

    2005-01-01

    The purpose of the paper is to analyze mobile payments in the mobile commerce scenario. Therefore, we first classify the mobile payment in the mobile commerce scenario by explaining general offer models, charging concepts, and intermediaries. Second, we describe the mobile payment reference model, especially, the mobile payment reference organization model and different mobile payment standard types. Finally, we conclude our findings.

  11. Reference dosimetry and small-field dosimetry in external beam radiotherapy: Results from a Danish intercomparison study

    DEFF Research Database (Denmark)

    Beierholm, Anders Ravnsborg; Behrens, Claus F.; Sibolt, Patrik

    methods was performed by DTU Nutech at six Danish clinics. The first part of the intercompa-rison regarded the consistency of reference dosimetry. Absorbed dose to water under reference conditions was measured using a Farmer ionization chamber, and was found to agree within 1 % with the daily dose checks......-specific correction factors for non-reference fields....

  12. Requirements for data integration platforms in biomedical research networks: a reference model.

    Science.gov (United States)

    Ganzinger, Matthias; Knaup, Petra

    2015-01-01

    Biomedical research networks need to integrate research data among their members and with external partners. To support such data sharing activities, an adequate information technology infrastructure is necessary. To facilitate the establishment of such an infrastructure, we developed a reference model for the requirements. The reference model consists of five reference goals and 15 reference requirements. Using the Unified Modeling Language, the goals and requirements are set into relation to each other. In addition, all goals and requirements are described textually in tables. This reference model can be used by research networks as a basis for a resource efficient acquisition of their project specific requirements. Furthermore, a concrete instance of the reference model is described for a research network on liver cancer. The reference model is transferred into a requirements model of the specific network. Based on this concrete requirements model, a service-oriented information technology architecture is derived and also described in this paper.

  13. Influence of size of the ionization chamber in determination of the quality of an X-ray field of references

    International Nuclear Information System (INIS)

    Viana, R.N.; Cassiano, D.H.; Peixoto, J.G.P.

    2005-01-01

    The quality of an X-ray field of reference can be evaluated with the determination of the values of the first and second half-value layer - 1 st and 2 nd CSR, from measurements carried out with appropriate ionisation chambers. The acceptance criteria of ISO 4037-1 states that the values of 1 st and 2 nd CSR may not differ by more than -5% of the reference values. Procedures have been developed on X-ray equipment PANTAK, model HF160, adjusted to produce a field of 48 keV X-ray, to investigate the determination of the values of 1 st and 2 nd CSR with the use of different ionization chambers of varying volumes. The initial results indicate that the values of 1 st and 2 nd CSR are influenced by the size of the ionization chamber used, which suggests the determination of algorithm for the determination of a single value of 1 st and 2 nd CSR

  14. Related work on reference modeling for collaborative networks

    NARCIS (Netherlands)

    Afsarmanesh, H.; Camarinha-Matos, L.M.; Camarinha-Matos, L.M.; Afsarmanesh, H.

    2008-01-01

    Several international research and development initiatives have led to development of models for organizations and organization interactions. These models and their approaches constitute a background for development of reference models for collaborative networks. A brief survey of work on modeling

  15. Reference model analysis of suitability for logistics management

    Directory of Open Access Journals (Sweden)

    Cezary Mańkowski

    2011-12-01

    Full Text Available Reference models are one of the many instruments aspiring to find into a set of different concepts, methods and techniques used in managing the logistics. Therefore, the aim of this paper is to present the results of assessing the suitability of reference models for solving logistical problems. This evaluation indicates that they are universal, support the realization of all the logistics management function in various areas, such as logistics of manufacturing glass products.

  16. The cost of model reference adaptive control - Analysis, experiments, and optimization

    Science.gov (United States)

    Messer, R. S.; Haftka, R. T.; Cudney, H. H.

    1993-01-01

    In this paper the performance of Model Reference Adaptive Control (MRAC) is studied in numerical simulations and verified experimentally with the objective of understanding how differences between the plant and the reference model affect the control effort. MRAC is applied analytically and experimentally to a single degree of freedom system and analytically to a MIMO system with controlled differences between the model and the plant. It is shown that the control effort is sensitive to differences between the plant and the reference model. The effects of increased damping in the reference model are considered, and it is shown that requiring the controller to provide increased damping actually decreases the required control effort when differences between the plant and reference model exist. This result is useful because one of the first attempts to counteract the increased control effort due to differences between the plant and reference model might be to require less damping, however, this would actually increase the control effort. Optimization of weighting matrices is shown to help reduce the increase in required control effort. However, it was found that eventually the optimization resulted in a design that required an extremely high sampling rate for successful realization.

  17. Equilibrium modeling of the TFCX poloidal field coil system

    International Nuclear Information System (INIS)

    Strickler, D.J.; Miller, J.B.; Rothe, K.E.; Peng, Y.K.M.

    1984-04-01

    The Toroidal Fusion Core Experiment (TFCX) isproposed to be an ignition device with a low safety factor (q approx. = 2.0), rf or rf-assisted startup, long inductive burn pulse (approx. 300 s), and an elongated plasma cross section (kappa = 1.6) with moderate triangularity (delta = 0.3). System trade studies have been carried out to assist in choosing an appropriate candidate for TFCX conceptual design. This report describes an important element in these system studies - the magnetohydrodynamic (MHD) equilibrium modeling of the TFCX poloidal field (PF) coil system and its impact on the choice of machine size. Reference design points for the all-super-conducting toroidal field (TF) coil (TFCX-S) and hybrid (TFCX-H) options are presented that satisfy given PF system criteria, including volt-second requirements during burn, mechanical configuration constraints, maximum field constraints at the superconducting PF coils, and plasma shape parameters. Poloidal coil current waveforms for the TFCX-S and TFCX-H reference designs consistent with the equilibrium requirements of the plasma startup, heating, and burn phases of a typical discharge scenario are calculated. Finally, a possible option for quasi-steady-state operation is discussed

  18. Instrument intercomparison in the high-energy mixed field at the CERN-EU reference field (CERF) facility

    CERN Document Server

    Caresana, Marco; Manessi, Giacomo; Ott, Klaus; Scherpelz, Robert; Silari, Marco

    2014-01-01

    This paper discusses an intercomparison campaign performed in the mixed radiation field at the CERN-EU (CERF) reference field facility. Various instruments were employed: conventional and extended-range rem counters including a novel instrument called LUPIN, a bubble detector using an active counting system (ABC 1260) and two tissue-equivalent proportional counters (TEPCs). The results show that the extended range instruments agree well within their uncertainties and within 1σ with the H*(10) FLUKA value. The conventional rem counters are in good agreement within their uncertainties and underestimate H*(10) as measured by the extended range instruments and as predicted by FLUKA. The TEPCs slightly overestimate the FLUKA value but they are anyhow consistent with it when taking the comparatively large total uncertainties into account, and indicate that the non-neutron part of the stray field accounts for ∼30 % of the total H*(10).

  19. Mapping the global football field: a sociological model of transnational forces within the world game.

    Science.gov (United States)

    Giulianotti, Richard; Robertson, Roland

    2012-06-01

    This paper provides a sociological model of the key transnational political and economic forces that are shaping the 'global football field'. The model draws upon, and significantly extends, the theory of the 'global field' developed previously by Robertson. The model features four quadrants, each of which contains a dominant operating principle, an 'elemental reference point', and an 'elemental theme'. The quadrants contain, first, neo-liberalism, associated with the individual and elite football clubs; second, neo-mercantilism, associated with nation-states and national football systems; third, international relations, associated with international governing bodies; and fourth, global civil society, associated with diverse institutions that pursue human development and/or social justice. We examine some of the interactions and tensions between the major institutional and ideological forces across the four quadrants. We conclude by examining how the weakest quadrant, featuring global civil society, may gain greater prominence within football. In broad terms, we argue that our four-fold model may be utilized to map and to examine other substantive research fields with reference to globalization. © London School of Economics and Political Science 2012.

  20. The CERN-EU high-energy Reference Field (CERF) facility: applications and latest developments

    Science.gov (United States)

    Silari, Marco; Pozzi, Fabio

    2017-09-01

    The CERF facility at CERN provides an almost unique high-energy workplace reference radiation field for the calibration and test of radiation protection instrumentation employed at high-energy accelerator facilities and for aircraft and space dosimetry. This paper describes the main features of the facility and supplies a non-exhaustive list of recent (as of 2005) applications for which CERF is used. Upgrade work started in 2015 to provide the scientific and industrial communities with a state-of-the-art reference facility is also discussed.

  1. Classical field theory in the space of reference frames. [Space-time manifold, action principle

    Energy Technology Data Exchange (ETDEWEB)

    Toller, M [Dipartimento di Matematica e Fisica, Libera Universita, Trento (Italy)

    1978-03-11

    The formalism of classical field theory is generalized by replacing the space-time manifold M by the ten-dimensional manifold S of all the local reference frames. The geometry of the manifold S is determined by ten vector fields corresponding to ten operationally defined infinitesimal transformations of the reference frames. The action principle is written in terms of a differential 4-form in the space S (the Lagrangian form). Densities and currents are represented by differential 3-forms in S. The field equations and the connection between symmetries and conservation laws (Noether's theorem) are derived from the action principle. Einstein's theory of gravitation and Maxwell's theory of electromagnetism are reformulated in this language. The general formalism can also be used to formulate theories in which charge, energy and momentum cannot be localized in space-time and even theories in which a space-time manifold cannot be defined exactly in any useful way.

  2. Fast tracking ICT infrastructure requirements and design, based on Enterprise Reference Architecture and matching Reference Models

    DEFF Research Database (Denmark)

    Bernus, Peter; Baltrusch, Rob; Vesterager, Johan

    2002-01-01

    The Globemen Consortium has developed the virtual enterprise reference architecture and methodology (VERAM), based on GERAM and developed reference models for virtual enterprise management and joint mission delivery. The planned virtual enterprise capability includes the areas of sales...

  3. Field Model: An Object-Oriented Data Model for Fields

    Science.gov (United States)

    Moran, Patrick J.

    2001-01-01

    We present an extensible, object-oriented data model designed for field data entitled Field Model (FM). FM objects can represent a wide variety of fields, including fields of arbitrary dimension and node type. FM can also handle time-series data. FM achieves generality through carefully selected topological primitives and through an implementation that leverages the potential of templated C++. FM supports fields where the nodes values are paired with any cell type. Thus FM can represent data where the field nodes are paired with the vertices ("vertex-centered" data), fields where the nodes are paired with the D-dimensional cells in R(sup D) (often called "cell-centered" data), as well as fields where nodes are paired with edges or other cell types. FM is designed to effectively handle very large data sets; in particular FM employs a demand-driven evaluation strategy that works especially well with large field data. Finally, the interfaces developed for FM have the potential to effectively abstract field data based on adaptive meshes. We present initial results with a triangular adaptive grid in R(sup 2) and discuss how the same design abstractions would work equally well with other adaptive-grid variations, including meshes in R(sup 3).

  4. OWL references in ORM conceptual modelling

    Science.gov (United States)

    Matula, Jiri; Belunek, Roman; Hunka, Frantisek

    2017-07-01

    Object Role Modelling methodology is the fact-based type of conceptual modelling. The aim of the paper is to emphasize a close connection to OWL documents and its possible mutual cooperation. The definition of entities or domain values is an indispensable part of the conceptual schema design procedure defined by the ORM methodology. Many of these entities are already defined in OWL documents. Therefore, it is not necessary to declare entities again, whereas it is possible to utilize references from OWL documents during modelling of information systems.

  5. Selection of References in Wind Turbine Model Predictive Control Design

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Hovgaard, Tobias

    2015-01-01

    a model predictive controller for a wind turbine. One of the important aspects for a tracking control problem is how to setup the optimal reference tracking problem, as it might be relevant to track, e.g., the three concurrent references: optimal pitch angle, optimal rotational speed, and optimal power......Lowering the cost of energy is one of the major focus areas in the wind turbine industry. Recent research has indicated that wind turbine controllers based on model predictive control methods can be useful in obtaining this objective. A number of design considerations have to be made when designing....... The importance if the individual references differ depending in particular on the wind speed. In this paper we investigate the performance of a reference tracking model predictive controller with two different setups of the used optimal reference signals. The controllers are evaluated using an industrial high...

  6. Instrument intercomparison in the high-energy mixed field at the CERN-EU reference field (CERF) facility.

    Science.gov (United States)

    Caresana, Marco; Helmecke, Manuela; Kubancak, Jan; Manessi, Giacomo Paolo; Ott, Klaus; Scherpelz, Robert; Silari, Marco

    2014-10-01

    This paper discusses an intercomparison campaign performed in the mixed radiation field at the CERN-EU (CERF) reference field facility. Various instruments were employed: conventional and extended-range rem counters including a novel instrument called LUPIN, a bubble detector using an active counting system (ABC 1260) and two tissue-equivalent proportional counters (TEPCs). The results show that the extended range instruments agree well within their uncertainties and within 1σ with the H*(10) FLUKA value. The conventional rem counters are in good agreement within their uncertainties and underestimate H*(10) as measured by the extended range instruments and as predicted by FLUKA. The TEPCs slightly overestimate the FLUKA value but they are anyhow consistent with it when taking the comparatively large total uncertainties into account, and indicate that the non-neutron part of the stray field accounts for ∼30 % of the total H*(10). © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. Temperature-field measurements of a premixed butane/air circular impinging-flame using reference-beam interferometry

    International Nuclear Information System (INIS)

    Qi, J.A.; Leung, C.W.; Wong, W.O.; Probert, S.D.

    2006-01-01

    Reference-beam interferometry (RBI) was applied to study the axisymmetric temperature fields of a small-scale, low Reynolds-number, low-pressure and fuel-rich premixed butane/air circular-flame jet, when it was impinging vertically upwards onto a horizontal copper plate. By maintaining a Reynolds number, Re, of 500 and an equivalence ratio, φ, of 1.8, interferograms of the impinging-flame jet were obtained for various nozzle-to-plate-distances. Temperature fields of the flame were then determined using the inverse Abel transformation from the obtained interferograms. Temperatures at several locations were measured experimentally with a T-type thermocouple: they were used as a reference to help in the determination as well as the validation. In the present study, a non-contact method has been successfully developed to measure the temperature fields of a circular impinging gas-fired flame jet

  8. On the importance of body posture and skin modelling with respect to in situ electric field strengths in magnetic field exposure scenarios

    Science.gov (United States)

    Schmid, Gernot; Hirtl, Rene

    2016-06-01

    The reference levels and maximum permissible exposure values for magnetic fields that are currently used have been derived from basic restrictions under the assumption of upright standing body models in a standard posture, i.e. with arms laterally down and without contact with metallic objects. Moreover, if anatomical modelling of the body was used at all, the skin was represented as a single homogeneous tissue layer. In the present paper we addressed the possible impacts of posture and skin modelling in scenarios of exposure to a 50 Hz uniform magnetic field on the in situ electric field strength in peripheral tissues, which must be limited in order to avoid peripheral nerve stimulation. We considered different body postures including situations where body parts form large induction loops (e.g. clasped hands) with skin-to-skin and skin-to-metal contact spots and compared the results obtained with a homogeneous single-layer skin model to results obtained with a more realistic two-layer skin representation consisting of a low-conductivity stratum corneum layer on top of a combined layer for the cellular epidermis and dermis. Our results clearly indicated that postures with loops formed of body parts may lead to substantially higher maximum values of induced in situ electric field strengths than in the case of standard postures due to a highly concentrated current density and in situ electric field strength in the skin-to-skin and skin-to-metal contact regions. With a homogeneous single-layer skin, as is used for even the most recent anatomical body models in exposure assessment, the in situ electric field strength may exceed the basic restrictions in such situations, even when the reference levels and maximum permissible exposure values are not exceeded. However, when using the more realistic two-layer skin model the obtained in situ electric field strengths were substantially lower and no violations of the basic restrictions occurred, which can be explained by the

  9. Lagrangian derivation of the two coupled field equations in the Janus cosmological model

    Science.gov (United States)

    Petit, Jean-Pierre; D'Agostini, G.

    2015-05-01

    After a review citing the results obtained in previous articles introducing the Janus Cosmological Model, consisting of a set of two coupled field equations, where one metrics refers to the positive masses and the other to the negative masses, which explains the observed cosmic acceleration and the nature of dark energy, we present the Lagrangian derivation of the model.

  10. Towards dynamic reference information models: Readiness for ICT mass customisation

    NARCIS (Netherlands)

    Verdouw, C.N.; Beulens, A.J.M.; Trienekens, J.H.; Verwaart, D.

    2010-01-01

    Current dynamic demand-driven networks make great demands on, in particular, the interoperability and agility of information systems. This paper investigates how reference information models can be used to meet these demands by enhancing ICT mass customisation. It was found that reference models for

  11. Quantum communication, reference frames, and gauge theory

    International Nuclear Information System (INIS)

    Enk, S. J. van

    2006-01-01

    We consider quantum communication in the case that the communicating parties not only do not share a reference frame but use imperfect quantum communication channels, in that each channel applies some fixed but unknown unitary rotation to each qubit. We discuss similarities and differences between reference frames within that quantum communication model and gauge fields in gauge theory. We generalize the concept of refbits and analyze various quantum communication protocols within the communication model

  12. Reference Model 6 (RM6): Oscillating Wave Energy Converter.

    Energy Technology Data Exchange (ETDEWEB)

    Bull, Diana L; Smith, Chris; Jenne, Dale Scott; Jacob, Paul; Copping, Andrea; Willits, Steve; Fontaine, Arnold; Brefort, Dorian; Gordon, Margaret Ellen; Copeland, Robert; Jepsen, Richard Alan

    2014-10-01

    This report is an addendum to SAND2013-9040: Methodology for Design and Economic Analysis of Marine Energy Conversion (MEC) Technologies. This report describes an Oscillating Water Column Wave Energy Converter reference model design in a complementary manner to Reference Models 1-4 contained in the above report. In this report, a conceptual design for an Oscillating Water Column Wave Energy Converter (WEC) device appropriate for the modeled reference resource site was identified, and a detailed backward bent duct buoy (BBDB) device design was developed using a combination of numerical modeling tools and scaled physical models. Our team used the methodology in SAND2013-9040 for the economic analysis that included costs for designing, manufacturing, deploying, and operating commercial-scale MEC arrays, up to 100 devices. The methodology was applied to identify key cost drivers and to estimate levelized cost of energy (LCOE) for this RM6 Oscillating Water Column device in dollars per kilowatt-hour ($/kWh). Although many costs were difficult to estimate at this time due to the lack of operational experience, the main contribution of this work was to disseminate a detailed set of methodologies and models that allow for an initial cost analysis of this emerging technology. This project is sponsored by the U.S. Department of Energy's (DOE) Wind and Water Power Technologies Program Office (WWPTO), within the Office of Energy Efficiency & Renewable Energy (EERE). Sandia National Laboratories, the lead in this effort, collaborated with partners from National Laboratories, industry, and universities to design and test this reference model.

  13. REFREP: a near-field model for a spent fuel repository

    International Nuclear Information System (INIS)

    Hautojaervi, A.; Vieno, T.

    1988-05-01

    A code package for near-field performance analysis of spent fuel disposal has been programmed. The conceptual models used are shortly described in connection with th model presentations. For more comprehensive descriptions the previous safety analysis and references therein are referred. The REFREP package consists of nine individual modules performing the following tasks: viewing and updating of the data files (UPDATE), calculating of the breaching times of canisters (CORRFLUX), calculating of stationary nuclide release rates using solubility values (MASSFLUX), calculating of actinide inventories from chain decay (INVENT), calculating of elemental inventories of actinides (ELEMENT), calculating of nuclide release rates according to congruent release (CONGRUNT), performing of sensitivity analysis for one variable (SENSIT), summing of release rates from individual canisters according to given probability distributions of canister breaching times (PROBREL), and forming a compact data file including all the input values (DATAOUT). The results have been shown to agree very well with the results of the previous safety analysis where near-field analysis was performed by means of separate codes and manual calculation. The REFREP model offers already at this stage some additional features to the old procedures and more versatile capabilities can easyly be added into the modular structure of the package. REFREP has been developed in a VAX-environment. Some changes in file handling might be necessary if the code is transferred to another computer

  14. Perceptual quality estimation of H.264/AVC videos using reduced-reference and no-reference models

    Science.gov (United States)

    Shahid, Muhammad; Pandremmenou, Katerina; Kondi, Lisimachos P.; Rossholm, Andreas; Lövström, Benny

    2016-09-01

    Reduced-reference (RR) and no-reference (NR) models for video quality estimation, using features that account for the impact of coding artifacts, spatio-temporal complexity, and packet losses, are proposed. The purpose of this study is to analyze a number of potentially quality-relevant features in order to select the most suitable set of features for building the desired models. The proposed sets of features have not been used in the literature and some of the features are used for the first time in this study. The features are employed by the least absolute shrinkage and selection operator (LASSO), which selects only the most influential of them toward perceptual quality. For comparison, we apply feature selection in the complete feature sets and ridge regression on the reduced sets. The models are validated using a database of H.264/AVC encoded videos that were subjectively assessed for quality in an ITU-T compliant laboratory. We infer that just two features selected by RR LASSO and two bitstream-based features selected by NR LASSO are able to estimate perceptual quality with high accuracy, higher than that of ridge, which uses more features. The comparisons with competing works and two full-reference metrics also verify the superiority of our models.

  15. A Service-Oriented E-Commerce Reference Architecture

    OpenAIRE

    Aulkemeier, Fabian; Schramm, Milan; Iacob, Maria Eugenia; van Hillegersberg, Jos

    2016-01-01

    Electronic commerce (e-commerce) is getting more and more important in people's every day shopping routines. Vendors who want to establish an online channel besides their traditional retail practice have to integrate the two supply chains. The underlying information technology systems should be able to support the integration of the new and old processes. While reference models are a popular means in designing this type of systems, the existing reference models in the field of e-commerce only...

  16. Religious Studies: The Shaping of a Field and a Guide to Reference Resources.

    Science.gov (United States)

    Lippy, Charles H.

    1992-01-01

    Discusses the development of religious studies as an academic discipline. Examines the work of leading thinkers in the field, including anthropologists Sir James Fraser and Edward Burnett Taylor, sociologist Max Weber, and psychologist Erik Erikson. Identifies some of the many reference works that deal with religious studies. (SG)

  17. Development of a TPC for energy and fluence references in low energies neutronic fields (from 8 keV to 5 MeV)

    International Nuclear Information System (INIS)

    Maire, Donovan

    2015-01-01

    In order to judge the measurement reliability, metrology requires to measure quantities with their uncertainties, in relation to a reference through a documented and unbroken chain of calibrations. In neutron radiation field, instrument response has to be known as a function of the neutron energy. Then detector calibrations are required using reference neutron fields. In France, primary reference neutron fields are held by the LNE-IRSN, at the Laboratory for Neutron Metrology and Dosimetry (LMDN). In order to improve reference neutron field characterization, the LNE-IRSN MIMAC μTPC has been developed. This detector is a Time Projection Chamber (TPC), using a gas at low pressure (30 mbar abs. to 1 bar abs.). Nuclear recoils are generated by neutron elastic scattering onto gas atoms. By measuring the nuclear recoil energy and scattering angle, the μTPC detector is able to measure the energy distribution of the neutron fluence between 8 keV and 5 MeV. The main challenge was to perform accurate spectrometry of neutron fields in the keV range, following a primary procedure. First of all, a metrological approach was followed in order to master every physical process taking part in the neutron detection. This approach led to develop the direct and inverse models, representing the detector response function and its inverse function respectively. Using this detailed characterization, the energy distribution of the neutron fluence has been measured for a continuous neutron field of 27 keV. The reconstructed energy is 28,2 ± 4,5 keV, the difference between μTPC integral fluence measurement and other measurement methods is less than 6%. The LNE-IRSN MIMAC μTPC system becomes the only one system able to measure simultaneously energy and fluence at energies lower than 100 keV, following a primary procedure. The project goal is then reached. These measurements at energies lower than 100 keV shows also a non-linearity between the ionization charge and the ion kinetic energy

  18. Reference Management Methodologies for Large Structural Models at Kennedy Space Center

    Science.gov (United States)

    Jones, Corey; Bingham, Ryan; Schmidt, Rick

    2011-01-01

    There have been many challenges associated with modeling some of NASA KSC's largest structures. Given the size of the welded structures here at KSC, it was critically important to properly organize model struc.ture and carefully manage references. Additionally, because of the amount of hardware to be installed on these structures, it was very important to have a means to coordinate between different design teams and organizations, check for interferences, produce consistent drawings, and allow for simple release processes. Facing these challenges, the modeling team developed a unique reference management methodology and model fidelity methodology. This presentation will describe the techniques and methodologies that were developed for these projects. The attendees will learn about KSC's reference management and model fidelity methodologies for large structures. The attendees will understand the goals of these methodologies. The attendees will appreciate the advantages of developing a reference management methodology.

  19. An implicit adaptation algorithm for a linear model reference control system

    Science.gov (United States)

    Mabius, L.; Kaufman, H.

    1975-01-01

    This paper presents a stable implicit adaptation algorithm for model reference control. The constraints for stability are found using Lyapunov's second method and do not depend on perfect model following between the system and the reference model. Methods are proposed for satisfying these constraints without estimating the parameters on which the constraints depend.

  20. Modeling transducer impulse responses for predicting calibrated pressure pulses with the ultrasound simulation program Field II

    DEFF Research Database (Denmark)

    Bæk, David; Jensen, Jørgen Arendt; Willatzen, Morten

    2010-01-01

    FIELD II is a simulation software capable of predicting the field pressure in front of transducers having any complicated geometry. A calibrated prediction with this program is, however, dependent on an exact voltage-to-surface acceleration impulse response of the transducer. Such impulse response...... is not calculated by FIELD II. This work investigates the usability of combining a one-dimensional multilayer transducer modeling principle with the FIELD II software. Multilayer here refers to a transducer composed of several material layers. Measurements of pressure and current from Pz27 piezoceramic disks...... transducer model and the FIELD II software in combination give good agreement with measurements....

  1. Stochastic quantization of field theories on the lattice and supersymmetrical models

    International Nuclear Information System (INIS)

    Aldazabal, Gerardo.

    1984-01-01

    Several aspects of the stochastic quantization method are considered. Specifically, field theories on the lattice and supersymmetrical models are studied. A non-linear sigma model is studied firstly, and it is shown that it is possible to obtain evolution equations written directly for invariant quantities. These ideas are generalized to obtain Langevin equations for the Wilson loops of non-abelian lattice gauge theories U (N) and SU (N). In order to write these equations, some different ways of introducing the constraints which the fields must satisfy are discussed. It is natural to have a strong coupling expansion in these equations. The correspondence with quantum field theory is established, and it is noticed that at all orders in the perturbation theory, Langevin equations reduce to Schwinger-Dyson equations. From another point of view, stochastic quantization is applied to large N matrix models on the lattice. As a result, a simple and systematic way of building reduced models is found. Referring to stochastic quantization in supersymmetric theories, a simple supersymmetric model is studied. It is shown that it is possible to write an evolution equation for the superfield wich leads to quantum field theory results in equilibrium. As the Langevin equation preserves supersymmetry, the property of dimensional reduction known for the quantum model is shown to be valid at all times. (M.E.L.) [es

  2. Towards a reference model for portfolio management for product development

    DEFF Research Database (Denmark)

    Larsson, Flemming

    2006-01-01

    The aim of this paper is to explore the concept of portfolio management for product development at company level. Departing from a combination of explorative interviews with industry professionals and a literature review a proposal for a reference model for portfolio management is developed....... The model consists of a set of defined and interrelated concepts which forms a coherent and consistent reference model that explicate the totality of the portfolio management concept at company level in terms of structure, processes and elements. The model simultaneously pinpoints, positions and integrates...... several central dimensions of portfolio management....

  3. Stochastic-field cavitation model

    International Nuclear Information System (INIS)

    Dumond, J.; Magagnato, F.; Class, A.

    2013-01-01

    Nonlinear phenomena can often be well described using probability density functions (pdf) and pdf transport models. Traditionally, the simulation of pdf transport requires Monte-Carlo codes based on Lagrangian “particles” or prescribed pdf assumptions including binning techniques. Recently, in the field of combustion, a novel formulation called the stochastic-field method solving pdf transport based on Eulerian fields has been proposed which eliminates the necessity to mix Eulerian and Lagrangian techniques or prescribed pdf assumptions. In the present work, for the first time the stochastic-field method is applied to multi-phase flow and, in particular, to cavitating flow. To validate the proposed stochastic-field cavitation model, two applications are considered. First, sheet cavitation is simulated in a Venturi-type nozzle. The second application is an innovative fluidic diode which exhibits coolant flashing. Agreement with experimental results is obtained for both applications with a fixed set of model constants. The stochastic-field cavitation model captures the wide range of pdf shapes present at different locations

  4. Stochastic-field cavitation model

    Science.gov (United States)

    Dumond, J.; Magagnato, F.; Class, A.

    2013-07-01

    Nonlinear phenomena can often be well described using probability density functions (pdf) and pdf transport models. Traditionally, the simulation of pdf transport requires Monte-Carlo codes based on Lagrangian "particles" or prescribed pdf assumptions including binning techniques. Recently, in the field of combustion, a novel formulation called the stochastic-field method solving pdf transport based on Eulerian fields has been proposed which eliminates the necessity to mix Eulerian and Lagrangian techniques or prescribed pdf assumptions. In the present work, for the first time the stochastic-field method is applied to multi-phase flow and, in particular, to cavitating flow. To validate the proposed stochastic-field cavitation model, two applications are considered. First, sheet cavitation is simulated in a Venturi-type nozzle. The second application is an innovative fluidic diode which exhibits coolant flashing. Agreement with experimental results is obtained for both applications with a fixed set of model constants. The stochastic-field cavitation model captures the wide range of pdf shapes present at different locations.

  5. The importance of the reference populations for coherent mortality forecasting models

    DEFF Research Database (Denmark)

    Kjærgaard, Søren; Canudas-Romo, Vladimir; Vaupel, James W.

    -population mortality models aiming to find the optimal of the set of countries to use as reference population and analyse the importance of the selection of countries. The two multi-population mortality models used are the Li-Lee model and the Double-Gap life expectancy forecasting model. The reference populations......Coherent forecasting models that take into consideration mortality changes observed in different countries are today among the essential tools for demographers, actuaries and other researchers interested in forecasts. Medium and long term life expectancy forecasts are compared for two multi...... is calculated taking into account all the possible combinations of a set of 20 industrialized countries. The different reference populations possibilities are compared by their forecast performance. The results show that the selection of countries for multi-population mortality models has a significant effect...

  6. Modeling of Coastal Effluent Transport: an Approach to Linking of Far-field and Near-field Models

    International Nuclear Information System (INIS)

    Yang, Zhaoqing; Khangaonkar, Tarang P.

    2008-01-01

    One of the challenges in effluent transport modeling in coastal tidal environments is the proper calculation of initial dilution in connection with the far-field transport model. In this study, an approach of external linkage of far-field and near-field effluent transport models is presented, and applied to simulate the effluent transport in the Port Angeles Harbor, Washington in the Strait of Juan de Fuca. A near-field plume model was used to calculate the effluent initial dilution and a three-dimensional (3-D) hydrodynamic model was developed to simulate the tidal circulation and far-field effluent transport in the Port Angeles Harbor. In the present study, the hydrodynamic model was driven by tides and surface winds. Observed water surface elevation and velocity data were used to calibrate the model over a period covering the neap-spring tidal cycle. The model was also validated with observed surface drogue trajectory data. The model successfully reproduced the tidal dynamics in the study area and good agreements between model results and observed data were obtained. This study demonstrated that the linkage between the near-field and far-field models in effluent transport modeling can be achieved through iteratively adjusting the model grid sizes such that the far-field modeled dilution ratio and effluent concentration in the effluent discharge model grid cell match the concentration calculated by the near-field plume model

  7. Methodology to define biological reference values in the environmental and occupational fields: the contribution of the Italian Society for Reference Values (SIVR).

    Science.gov (United States)

    Aprea, Maria Cristina; Scapellato, Maria Luisa; Valsania, Maria Carmen; Perico, Andrea; Perbellini, Luigi; Ricossa, Maria Cristina; Pradella, Marco; Negri, Sara; Iavicoli, Ivo; Lovreglio, Piero; Salamon, Fabiola; Bettinelli, Maurizio; Apostoli, Pietro

    2017-04-21

    Biological reference values (RVs) explore the relationships between humans and their environment and habits. RVs are fundamental in the environmental field for assessing illnesses possibly associated with environmental pollution, and also in the occupational field, especially in the absence of established biological or environmental limits. The Italian Society for Reference Values (SIVR) determined to test criteria and procedures for the definition of RVs to be used in the environmental and occupational fields. The paper describes the SIVR methodology for defining RVs of xenobiotics and their metabolites. Aspects regarding the choice of population sample, the quality of analytical data, statistical analysis and control of variability factors are considered. The simultaneous interlaboratory circuits involved can be expected to increasingly improve the quality of the analytical data. Examples of RVs produced by SIVR are presented. In particular, levels of chromium, mercury, ethylenethiourea, 3,5,6-trichloro-2-pyridinol, 2,5-hexanedione, 1-hydroxypyrene and t,t-muconic acid measured in urine and expressed in micrograms/g creatinine (μg/g creat) or micrograms/L (μg/L) are reported. With the proposed procedure, SIVR intends to make its activities known to the scientific community in order to increase the number of laboratories involved in the definition of RVs for the Italian population. More research is needed to obtain further RVs in different biological matrices, such as hair, nails and exhaled breath. It is also necessary to update and improve the present reference values and broaden the portfolio of chemicals for which RVs are available. In the near future, SIVR intends to expand its scientific activity by using a multivariate approach for xenobiotics that may have a common origin, and to define RVs separately for children who may be exposed more than adults and be more vulnerable.

  8. Referent 3D tumor model at cellular level in radionuclide therapy

    International Nuclear Information System (INIS)

    Spaic, R.; Ilic, R.D.; Petrovic, B.J.

    2002-01-01

    Aim Conventional internal dosimetry has a lot of limitations because of tumor dose nonuniformity. The best approach for absorbed dose at cellular level for different tumors in radionuclide therapy calculation is Monte Carlo method. The purpose of this study is to introduce referent tumor 3D model at cellular level for Monte Carlo simulation study in radionuclide therapy. Material and Methods The moment when tumor is detectable and when same therapy can start is time period in which referent 3D tumor model at cellular level was defined. In accordance with tumor growth rate at that moment he was a sphere with same radius (10 000 μm). In that tumor there are cells or cluster of cells, which are randomly distributed spheres. Distribution of cells/cluster of cells can be calculated from histology data but it was assumed that this distribution is normal with the same mean value and standard deviation (100±50 mm). Second parameter, which was selected to define referent tumor, is volume density of cells (30%). In this referent tumor there are no necroses. Stroma is defined as space between spheres with same concentration of materials as in spheres. Results: Referent tumor defined on this way have about 2,2 10 5 cells or cluster of cells random distributed. Using this referent 3D tumor model and for same concentration of radionuclides (1:100) and energy of beta emitters (1000 keV) which are homogeneously distributed in labeled cells absorbed dose for all cells was calculated. Simulations are done using FOTELP Monte Carlo code, which is modified for this purposes. Results of absorbed dose in cells are given in numerical values (1D distribution) and as the images (2D or 3D distributions). Conclusion Geometrical module for Monte Carlo simulation study can be standardized by introducing referent 3D tumor model at cellular level. This referent 3D tumor model gives most realistic presentation of different tumors at the moment of their detectability. Referent 3D tumor model at

  9. Direct model reference adaptive control with application to flexible robots

    Science.gov (United States)

    Steinvorth, Rodrigo; Kaufman, Howard; Neat, Gregory W.

    1992-01-01

    A modification to a direct command generator tracker-based model reference adaptive control (MRAC) system is suggested in this paper. This modification incorporates a feedforward into the reference model's output as well as the plant's output. Its purpose is to eliminate the bounded model following error present in steady state when previous MRAC systems were used. The algorithm was evaluated using the dynamics for a single-link flexible-joint arm. The results of these simulations show a response with zero steady state model following error. These results encourage further use of MRAC for various types of nonlinear plants.

  10. SITE-94. Modelling of near-field chemistry for SITE-94

    Energy Technology Data Exchange (ETDEWEB)

    Arthur, R.; Apted, M. [QuantiSci, Denver, CO (United States)

    1996-12-01

    This report evaluates methods for the incorporation of site data into models simulating the long-term chemical evolution of the near field. The models are based on limiting conditions at equilibrium, or steady state, in three closed systems representing fully saturated bentonite, Fe{sup o} corrosion products of the canister and spent fuel. A l kg reference mass of site groundwater is assumed to equilibrate first with bentonite and then with the canister`s corrosion products. A third closed system representing spent fuel is modeled in terms of spent-fuel dissolution in 1 kg of water evolved from the canister, coupled with steady-state constraints on the rate of oxidant production by {alpha} radiolysis of H{sub 2}O(l). Precipitation of secondary minerals controlling the solubilities of radioelements dissolved from spent fuel is also simulated in this model. Version 7.2 of the EQ3/6 geochemical software package and its supporting composite thermodynamic database, dataO.com.R22, are used to carry out these calculations. It is concluded that chemical models of near-field evolution combined with thermodynamic models of radionuclide speciation-solubility behavior can assist efforts to assimilate site characterization data into the performance assessment process, and to deal with uncertainties that are inherent in both site properties and in concepts of near field chemistry. It is essential, however, that expert judgement and prudence should be exercised such that model results are conservative with respect to acknowledged and documented uncertainties. Most importantly, it must be recognized that it is probably not possible to model with a high-level of accuracy the complex chemical environments and long timescales involved in disposal technologies for nuclear wastes. For performance assessment, however, only bounding values are needed, and modeling approaches such as described in this report are useful for this purpose. Technical peer review and cross-comparisons of near-field

  11. Discrete Model Reference Adaptive Control System for Automatic Profiling Machine

    Directory of Open Access Journals (Sweden)

    Peng Song

    2012-01-01

    Full Text Available Automatic profiling machine is a movement system that has a high degree of parameter variation and high frequency of transient process, and it requires an accurate control in time. In this paper, the discrete model reference adaptive control system of automatic profiling machine is discussed. Firstly, the model of automatic profiling machine is presented according to the parameters of DC motor. Then the design of the discrete model reference adaptive control is proposed, and the control rules are proven. The results of simulation show that adaptive control system has favorable dynamic performances.

  12. Organizational Learning Supported by Reference Architecture Models

    DEFF Research Database (Denmark)

    Nardello, Marco; Møller, Charles; Gøtze, John

    2017-01-01

    of an emerging technical standard specific for the manufacturing industry. Global manufacturing experts consider the Reference Architecture Model Industry 4.0 (RAMI4.0) as one of the corner stones for the implementation of Industry 4.0. The instantiation contributed to organizational learning in the laboratory...

  13. Model reference adaptive control and adaptive stability augmentation

    DEFF Research Database (Denmark)

    Henningsen, Arne; Ravn, Ole

    1993-01-01

    A comparison of the standard concepts in MRAC design suggests that a combination of the implicit and the explicit design techniques may lead to an improvement of the overall system performance in the presence of unmodelled dynamics. Using the ideas of adaptive stability augmentation a combined...... stability augmented model reference design is proposed. By utilizing the closed-loop control error, a simple auxiliary controller is tuned, using a normalized MIT rule for the parameter adjustment. The MIT adjustment is protected against the effects of unmodelled dynamics by lowpass filtering...... of the gradient. The proposed method is verified through simulation results indicating that the method may lead to an improvement of the model reference controller in the presence of unmodelled dynamics...

  14. Reliability of different mark-recapture methods for population size estimation tested against reference population sizes constructed from field data.

    Directory of Open Access Journals (Sweden)

    Annegret Grimm

    Full Text Available Reliable estimates of population size are fundamental in many ecological studies and biodiversity conservation. Selecting appropriate methods to estimate abundance is often very difficult, especially if data are scarce. Most studies concerning the reliability of different estimators used simulation data based on assumptions about capture variability that do not necessarily reflect conditions in natural populations. Here, we used data from an intensively studied closed population of the arboreal gecko Gehyra variegata to construct reference population sizes for assessing twelve different population size estimators in terms of bias, precision, accuracy, and their 95%-confidence intervals. Two of the reference populations reflect natural biological entities, whereas the other reference populations reflect artificial subsets of the population. Since individual heterogeneity was assumed, we tested modifications of the Lincoln-Petersen estimator, a set of models in programs MARK and CARE-2, and a truncated geometric distribution. Ranking of methods was similar across criteria. Models accounting for individual heterogeneity performed best in all assessment criteria. For populations from heterogeneous habitats without obvious covariates explaining individual heterogeneity, we recommend using the moment estimator or the interpolated jackknife estimator (both implemented in CAPTURE/MARK. If data for capture frequencies are substantial, we recommend the sample coverage or the estimating equation (both models implemented in CARE-2. Depending on the distribution of catchabilities, our proposed multiple Lincoln-Petersen and a truncated geometric distribution obtained comparably good results. The former usually resulted in a minimum population size and the latter can be recommended when there is a long tail of low capture probabilities. Models with covariates and mixture models performed poorly. Our approach identified suitable methods and extended options to

  15. The PTB thermal neutron reference field at GeNF

    International Nuclear Information System (INIS)

    Boettger, R.; Friedrich, H.; Janssen, H.

    2004-01-01

    The experimental setup and procedure for the characterization of the thermal neutron reference field established at the Geesthacht neutron facility (GeNF) of the GKSS is described. The neutron beam, free in air, with a maximum flux of 10 6 s -1 , can easily be reduced to less than 10 4 s -1 by using a diaphragm variable in size and without changing the beam divergence. Also, the spectral distribution with a mean energy of 45 meV, measured by time-of-flight over a 6.6 m long flight path, is independent of the beam current chosen. In the 2002/2003 experiments reported here, a 6 Li glass detector was employed to determine the absolute beam current and to calibrate the 3 He transmission beam monitor. In addition, activation measurements of gold foils were carried out at a reduced beam divergence. The results agree within ±2%. Furthermore, the beam is characterized by a low gamma background intensity and a negligible fraction of epithermal neutrons. Irradiations in combination with a scanner device to achieve a homogeneously illuminated scan field have shown that the thermal beam is well suited for dosemeter development and for the calibration of radiation protection instruments. (orig.)

  16. The PTB thermal neutron reference field at GeNF

    Energy Technology Data Exchange (ETDEWEB)

    Boettger, R.; Friedrich, H.; Janssen, H.

    2004-07-01

    The experimental setup and procedure for the characterization of the thermal neutron reference field established at the Geesthacht neutron facility (GeNF) of the GKSS is described. The neutron beam, free in air, with a maximum flux of 10{sup 6} s{sup -1}, can easily be reduced to less than 10{sup 4} s{sup -1} by using a diaphragm variable in size and without changing the beam divergence. Also, the spectral distribution with a mean energy of 45 meV, measured by time-of-flight over a 6.6 m long flight path, is independent of the beam current chosen. In the 2002/2003 experiments reported here, a {sup 6}Li glass detector was employed to determine the absolute beam current and to calibrate the {sup 3}He transmission beam monitor. In addition, activation measurements of gold foils were carried out at a reduced beam divergence. The results agree within {+-}2%. Furthermore, the beam is characterized by a low gamma background intensity and a negligible fraction of epithermal neutrons. Irradiations in combination with a scanner device to achieve a homogeneously illuminated scan field have shown that the thermal beam is well suited for dosemeter development and for the calibration of radiation protection instruments. (orig.)

  17. A note on perfect scalar fields

    International Nuclear Information System (INIS)

    Unnikrishnan, Sanil; Sriramkumar, L.

    2010-01-01

    We derive a condition on the Lagrangian density describing a generic, single, noncanonical scalar field, by demanding that the intrinsic, nonadiabatic pressure perturbation associated with the scalar field vanishes identically. Based on the analogy with perfect fluids, we refer to such fields as perfect scalar fields. It is common knowledge that models that depend only on the kinetic energy of the scalar field (often referred to as pure kinetic models) possess no nonadiabatic pressure perturbation. While we are able to construct models that seemingly depend on the scalar field and also do not contain any nonadiabatic pressure perturbation, we find that all such models that we construct allow a redefinition of the field under which they reduce to pure kinetic models. We show that, if a perfect scalar field drives inflation, then, in such situations, the first slow roll parameter will always be a monotonically decreasing function of time. We point out that this behavior implies that these scalar fields cannot lead to features in the inflationary, scalar perturbation spectrum.

  18. Model Predictive Control for Offset-Free Reference Tracking

    Czech Academy of Sciences Publication Activity Database

    Belda, Květoslav

    2016-01-01

    Roč. 5, č. 1 (2016), s. 8-13 ISSN 1805-3386 Institutional support: RVO:67985556 Keywords : offset-free reference tracking * predictive control * ARX model * state-space model * multi-input multi-output system * robotic system * mechatronic system Subject RIV: BC - Control Systems Theory http://library.utia.cas.cz/separaty/2016/AS/belda-0458355.pdf

  19. Nuclear energy - Reference beta-particle radiation - Part 2: Calibration fundamentals related to basic quantities characterizing the radiation field

    International Nuclear Information System (INIS)

    2004-01-01

    ISO 6980 consists of the following parts, under the general title Nuclear energy - Reference beta-particle radiation: Part 1: Method of production; Part 2: Calibration fundamentals related to basic quantities characterizing the radiation field; Part 3: Calibration of area and personal dosimeters and determination of their response as a function of energy and angle of incidence. This part 2 of ISO 6980 specifies methods for the measurement of the directional absorbed-dose rate in a tissue-equivalent slab phantom in the ISO 6980 reference beta-particle radiation fields. The energy range of the beta-particle-emitting isotopes covered by these reference radiations is 0.066 to 3.54 MeV (maximum energy). Radiation energies outside this range are beyond the scope of this standard. While measurements in a reference geometry (depth of 0.07 mm at perpendicular incidence in a tissue-equivalent slab phantom) with a reference class extrapolation chamber are dealt with in detail, the use of other measurement systems and measurements in other geometries are also described, although in less detail. The ambient dose equivalent, H*(10) as used for area monitoring of strongly penetrating radiation, is not an appropriate quantity for any beta radiation, even for that penetrating a 10 mm thick layer of ICRU tissue (i.e. E max > 2 MeV). If adequate protection is provided at 0.07 mm, only rarely will one be concerned with other depths, for example 3 mm. This document is geared towards organizations wishing to establish reference-class dosimetry capabilities for beta particles, and serves as a guide to the performance of dosimetry with the reference class extrapolation chamber for beta-particle dosimetry in other fields. Guidance is also provided on the statement of measurement uncertainties

  20. Standardization of reference radiation field of beta for 85Kr using extrapolation chamber

    International Nuclear Information System (INIS)

    Nazaroh; Fendinugroho

    2013-01-01

    Standardization of reference radiation field of beta for 85 Kr in PTKMR-BATAN Laboratory has been performed at the SDD's 30 cm by using extrapolation chamber detector, coupled with Uni dose electrometer. The result was : (8.98±3 %) mGy/h, at 95 % confidence level. The aim of standardization of reference radiation field is to support radiation protection and safety program, provided by the International Atomic Energy Agency to its Member States, included BATAN-Indonesia, especially, PTKMR. The aim of radiation protection program and safety program is to promote an internationally harmonized approach for radiation measurement in protection level, besides for calibration of radiation measuring instrument, which users spread across Indonesia, with the number of about 795 firms in the year of 2012. These benefits can be felt by workers, communities and the environment, because by calibration, measurement survey meter, pocket dosimeter and TLD to be more accurate so that the radiation dose received by radiation workers is accurate and can be ascertained in a specified period, not to exceed a predetermined NBD by BAPETEN. The aim of this calibration is appropriate with the primary objective of calibration on IAEA/TRS16:2000. (author)

  1. Frontal eye fields involved in shifting frame of reference within working memory for scenes

    DEFF Research Database (Denmark)

    Wallentin, Mikkel; Roepstorff, Andreas; Burgess, Neil

    2008-01-01

    Working memory (WM) evoked by linguistic cues for allocentric spatial and egocentric spatial aspects of a visual scene was investigated by correlating fMRI BOLD signal (or "activation") with performance on a spatial-relations task. Subjects indicated the relative positions of a person or object...... (referenced by the personal pronouns "he/she/it") in a previously-shown image relative to either themselves (egocentric reference frame) or shifted to a reference frame anchored in another person or object in the image (allocentric reference frame), e.g. "Was he in front of you/her?" Good performers had both...... shorter response time and more correct responses than poor performers in both tasks. These behavioural variables were entered into a principal component analysis. The first component reflected generalised performance level. We found that the frontal eye fields (FEF), bilaterally, had a higher BOLD...

  2. Assessment of induced radio-frequency electromagnetic fields in various anatomical human body models

    International Nuclear Information System (INIS)

    Kuehn, Sven; Jennings, Wayne; Christ, Andreas; Kuster, Niels

    2009-01-01

    The reference levels for testing compliance of human exposure with radio-frequency (RF) safety limits have been derived from very simplified models of the human. In order to validate these findings for anatomical models, we investigated the absorption characteristics for various anatomies ranging from 6 year old child to large adult male by numerical modeling. We address the exposure to plane-waves incident from all major six sides of the humans with two orthogonal polarizations each. Worst-case scattered field exposure scenarios have been constructed in order to test the implemented procedures of current in situ compliance measurement standards (spatial averaging versus peak search). Our findings suggest that the reference levels of current electromagnetic (EM) safety guidelines for demonstrating compliance as well as some of the current measurement standards are not consistent with the basic restrictions and need to be revised.

  3. Assessment of induced radio-frequency electromagnetic fields in various anatomical human body models

    Energy Technology Data Exchange (ETDEWEB)

    Kuehn, Sven; Jennings, Wayne; Christ, Andreas; Kuster, Niels [Foundation for Research on Information Technologies in Society (IT' IS), Zuerich (Switzerland)], E-mail: kuehn@itis.ethz.ch

    2009-02-21

    The reference levels for testing compliance of human exposure with radio-frequency (RF) safety limits have been derived from very simplified models of the human. In order to validate these findings for anatomical models, we investigated the absorption characteristics for various anatomies ranging from 6 year old child to large adult male by numerical modeling. We address the exposure to plane-waves incident from all major six sides of the humans with two orthogonal polarizations each. Worst-case scattered field exposure scenarios have been constructed in order to test the implemented procedures of current in situ compliance measurement standards (spatial averaging versus peak search). Our findings suggest that the reference levels of current electromagnetic (EM) safety guidelines for demonstrating compliance as well as some of the current measurement standards are not consistent with the basic restrictions and need to be revised.

  4. Efficient Adoption and Assessment of Multiple Process Improvement Reference Models

    Directory of Open Access Journals (Sweden)

    Simona Jeners

    2013-06-01

    Full Text Available A variety of reference models such as CMMI, COBIT or ITIL support IT organizations to improve their processes. These process improvement reference models (IRMs cover different domains such as IT development, IT Services or IT Governance but also share some similarities. As there are organizations that address multiple domains and need to coordinate their processes in their improvement we present MoSaIC, an approach to support organizations to efficiently adopt and conform to multiple IRMs. Our solution realizes a semantic integration of IRMs based on common meta-models. The resulting IRM integration model enables organizations to efficiently implement and asses multiple IRMs and to benefit from synergy effects.

  5. Modal-space reference-model-tracking fuzzy control of earthquake excited structures

    Science.gov (United States)

    Park, Kwan-Soon; Ok, Seung-Yong

    2015-01-01

    This paper describes an adaptive modal-space reference-model-tracking fuzzy control technique for the vibration control of earthquake-excited structures. In the proposed approach, the fuzzy logic is introduced to update optimal control force so that the controlled structural response can track the desired response of a reference model. For easy and practical implementation, the reference model is constructed by assigning the target damping ratios to the first few dominant modes in modal space. The numerical simulation results demonstrate that the proposed approach successfully achieves not only the adaptive fault-tolerant control system against partial actuator failures but also the robust performance against the variations of the uncertain system properties by redistributing the feedback control forces to the available actuators.

  6. Establishing a business process reference model for Universities

    DEFF Research Database (Denmark)

    Svensson, Carsten; Hvolby, Hans-Henrik

    2012-01-01

    Modern universities are by any standard complex organizations that, from an IT perspective, present a number of unique challenges. This paper will propose establishing a business process reference framework. The benefit to the users would be a better understanding of the system landscape, business......) have gained popularity among organizations in both the private and public sectors. We speculate that this success can be replicated in a university setting. Furthermore the paper will outline how the research group suggests moving ahead with the research which will lead to a reference model....

  7. Reference-data modelling for tracking and tracing

    NARCIS (Netherlands)

    Dorp, van C.A.

    2004-01-01

    Subject headings: supply chain, tracking and tracing, reference-data modelling

  8. Modeling uptake kinetics of cadmium by field-grown lettuce

    Energy Technology Data Exchange (ETDEWEB)

    Chen Weiping [Department of Environmental Sciences, University of California, 900 University Avenue, Riverside, CA 92521 (United States)], E-mail: chenweip@yahoo.com.cn; Li Lianqing [Institute of Resources, Ecosystem and Environment of Agriculture, Nanjing Agricultural University, Nanjing 210095 (China); Chang, Andrew C.; Wu Laosheng [Department of Environmental Sciences, University of California, 900 University Avenue, Riverside, CA 92521 (United States); Kwon, Soon-Ik [Agricultural Environmental and Ecology Division, National Institute of Agricultural Science and Technology, Suwon 441-707 (Korea, Republic of); Bottoms, Rick [Desert Research and Extension Center, 1004 East Holton Road, El Centro, CA 92243 (United States)

    2008-03-15

    Cadmium uptake by field grown Romaine lettuce treated with P-fertilizers of different Cd levels was investigated over an entire growing season. Results indicated that the rate of Cd uptake at a given time of the season can be satisfactorily described by the Michaelis-Menten kinetics, that is, plant uptake increases as the Cd concentration in soil solution increases, and it gradually approaches a saturation level. However, the rate constant of the Michaelis-Menten kinetics changes over the growing season. Under a given soil Cd level, the cadmium content in plant tissue decreases exponentially with time. To account for the dynamic nature of Cd uptake, a kinetic model integrating the time factor was developed to simulate Cd plant uptake over the growing season: C{sub Plant} = C{sub Solution} . PUF{sub max} . exp[-b . t], where C{sub Plant} and C{sub Solution} refer to the Cd content in plant tissue and soil solution, respectively, PUF{sub max} and b are kinetic constants. - A kinetic model was developed to evaluate the uptake of Cd under field conditions.

  9. Modeling uptake kinetics of cadmium by field-grown lettuce

    International Nuclear Information System (INIS)

    Chen Weiping; Li Lianqing; Chang, Andrew C.; Wu Laosheng; Kwon, Soon-Ik; Bottoms, Rick

    2008-01-01

    Cadmium uptake by field grown Romaine lettuce treated with P-fertilizers of different Cd levels was investigated over an entire growing season. Results indicated that the rate of Cd uptake at a given time of the season can be satisfactorily described by the Michaelis-Menten kinetics, that is, plant uptake increases as the Cd concentration in soil solution increases, and it gradually approaches a saturation level. However, the rate constant of the Michaelis-Menten kinetics changes over the growing season. Under a given soil Cd level, the cadmium content in plant tissue decreases exponentially with time. To account for the dynamic nature of Cd uptake, a kinetic model integrating the time factor was developed to simulate Cd plant uptake over the growing season: C Plant = C Solution . PUF max . exp[-b . t], where C Plant and C Solution refer to the Cd content in plant tissue and soil solution, respectively, PUF max and b are kinetic constants. - A kinetic model was developed to evaluate the uptake of Cd under field conditions

  10. Jobs and Economic Development Impact (JEDI) User Reference Guide: Fast Pyrolysis Biorefinery Model

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yimin [National Renewable Energy Lab. (NREL), Golden, CO (United States); Goldberg, Marshall [MRG and Associates, Nevada City, CA (United States)

    2015-02-01

    This guide -- the JEDI Fast Pyrolysis Biorefinery Model User Reference Guide -- was developed to assist users in operating and understanding the JEDI Fast Pyrolysis Biorefinery Model. The guide provides information on the model's underlying methodology, as well as the parameters and data sources used to develop the cost data utilized in the model. This guide also provides basic instruction on model add-in features and a discussion of how the results should be interpreted. Based on project-specific inputs from the user, the JEDI Fast Pyrolysis Biorefinery Model estimates local (e.g., county- or state-level) job creation, earnings, and output from total economic activity for a given fast pyrolysis biorefinery. These estimates include the direct, indirect and induced economic impacts to the local economy associated with the construction and operation phases of biorefinery projects.Local revenue and supply chain impacts as well as induced impacts are estimated using economic multipliers derived from the IMPLAN software program. By determining the local economic impacts and job creation for a proposed biorefinery, the JEDI Fast Pyrolysis Biorefinery Model can be used to field questions about the added value biorefineries might bring to a local community.

  11. Computers in field ion microscopy

    International Nuclear Information System (INIS)

    Suvorov, A.L.; Razinkova, T.L.; Sokolov, A.G.

    1980-01-01

    A review is presented of computer applications in field ion microscopy (FIM). The following topics are discussed in detail: (1) modeling field ion images in perfect crystals, (2) a general scheme of modeling, (3) modeling of the process of field evaporation, (4) crystal structure defects, (5) alloys, and (6) automation of FIM experiments and computer-assisted processing of real images. 146 references are given

  12. Children and adults exposed to electromagnetic fields at the ICNIRP reference levels: theoretical assessment of the induced peak temperature increase.

    Science.gov (United States)

    Bakker, J F; Paulides, M M; Neufeld, E; Christ, A; Kuster, N; van Rhoon, G C

    2011-08-07

    To avoid potentially adverse health effects of electromagnetic fields (EMF), the International Commission on Non-Ionizing Radiation Protection (ICNIRP) has defined EMF reference levels. Restrictions on induced whole-body-averaged specific absorption rate (SAR(wb)) are provided to keep the whole-body temperature increase (T(body, incr)) under 1 °C during 30 min. Additional restrictions on the peak 10 g spatial-averaged SAR (SAR(10g)) are provided to prevent excessive localized tissue heating. The objective of this study is to assess the localized peak temperature increase (T(incr, max)) in children upon exposure at the reference levels. Finite-difference time-domain modeling was used to calculate T(incr, max) in six children and two adults exposed to orthogonal plane-wave configurations. We performed a sensitivity study and Monte Carlo analysis to assess the uncertainty of the results. Considering the uncertainties in the model parameters, we found that a peak temperature increase as high as 1 °C can occur for worst-case scenarios at the ICNIRP reference levels. Since the guidelines are deduced from temperature increase, we used T(incr, max) as being a better metric to prevent excessive localized tissue heating instead of localized peak SAR. However, we note that the exposure time should also be considered in future guidelines. Hence, we advise defining limits on T(incr, max) for specified durations of exposure.

  13. Vortex ring state by full-field actuator disc model

    Energy Technology Data Exchange (ETDEWEB)

    Soerensen, J.N.; Shen, W.Z.; Munduate, X. [DTU, Dept. of Energy Engineering, Lyngby (Denmark)

    1997-08-01

    One-dimensional momentum theory provides a simple analytical tool for analysing the gross flow behavior of lifting propellers and rotors. Combined with a blade-element strip-theory approach, it has for many years been the most popular model for load and performance predictions of wind turbines. The model works well at moderate and high wind velocities, but is not reliable at small wind velocities, where the expansion of the wake is large and the flow field behind the rotor dominated by turbulent mixing. This is normally referred to as the turbulent wake state or the vortex ring state. In the vortex ring state, momentum theory predicts a decrease of thrust whereas the opposite is found from experiments. The reason for the disagreement is that recirculation takes place behind the rotor with the consequence that the stream tubes past the rotor becomes effectively chocked. This represents a condition at which streamlines no longer carry fluid elements from far upstream to far downstream, hence one-dimensional momentum theory is invalid and empirical corrections have to be introduced. More sophisticated analytical or semi-analytical rotor models have been used to describe stationary flow fields for heavily loaded propellers. In recent years generalized actuator disc models have been developed, but up to now no detailed computations of the turbulent wake state or the vortex ring state have been performed. In the present work the phenomenon is simulated by direct simulation of the Navier-Stokes equations, where the influence of the rotor on the flow field is modelled simply by replacing the blades by an actuator disc with a constant normal load. (EG) 13 refs.

  14. High Field Linear Magnetoresistance Sensors with Perpendicular Anisotropy L10-FePt Reference Layer

    Directory of Open Access Journals (Sweden)

    X. Liu

    2016-01-01

    Full Text Available High field linear magnetoresistance is an important feature for magnetic sensors applied in magnetic levitating train and high field positioning measurements. Here, we investigate linear magnetoresistance in Pt/FePt/ZnO/Fe/Pt multilayer magnetic sensor, where FePt and Fe ferromagnetic layers exhibit out-of-plane and in-plane magnetic anisotropy, respectively. Perpendicular anisotropy L10-FePt reference layer with large coercivity and high squareness ratio was obtained by in situ substrate heating. Linear magnetoresistance is observed in this sensor in a large range between +5 kOe and −5 kOe with the current parallel to the film plane. This L10-FePt based sensor is significant for the expansion of linear range and the simplification of preparation for future high field magnetic sensors.

  15. Technical note: A simple approach for efficient collection of field reference data for calibrating remote sensing mapping of northern wetlands

    Directory of Open Access Journals (Sweden)

    M. Gålfalk

    2018-03-01

    Full Text Available The calibration and validation of remote sensing land cover products are highly dependent on accurate field reference data, which are costly and practically challenging to collect. We describe an optical method for collection of field reference data that is a fast, cost-efficient, and robust alternative to field surveys and UAV imaging. A lightweight, waterproof, remote-controlled RGB camera (GoPro HERO4 Silver, GoPro Inc. was used to take wide-angle images from 3.1 to 4.5 m in altitude using an extendable monopod, as well as representative near-ground (< 1 m images to identify spectral and structural features that correspond to various land covers in present lighting conditions. A semi-automatic classification was made based on six surface types (graminoids, water, shrubs, dry moss, wet moss, and rock. The method enables collection of detailed field reference data, which is critical in many remote sensing applications, such as satellite-based wetland mapping. The method uses common non-expensive equipment, does not require special skills or training, and is facilitated by a step-by-step manual that is included in the Supplement. Over time a global ground cover database can be built that can be used as reference data for studies of non-forested wetlands from satellites such as Sentinel 1 and 2 (10 m pixel size.

  16. Researching Refugee and Forced Migration Studies: An Introduction to the Field and the Reference Literature.

    Science.gov (United States)

    Mason, Elisa

    1999-01-01

    Describes the evolution of refugee and forced migration studies, identifies factors that render it a challenging field to research, and highlights a variety of Internet-based and other electronic resources that can be used to locate monographs, periodicals, grey literature, and current information. Provides a bibliography of reference materials in…

  17. Health-related biological effects of electric, magnetic, and electro-magnetic fields with special reference to nonthermal effects

    International Nuclear Information System (INIS)

    Stevenson, A.F.G.

    1993-02-01

    This expert report is a supplement to the report by L. von Klitzing (The actions and effects of electric, magnetic, and electro-magnetic fields in man with special reference to athermal effects) and concerns in particular the biological effects on cationic homeostasis and cell regulation with special reference to calcium and the effects on the pineal gland. The report concludes with statements on teratogenicity, concerogenicity, mutagenicity and a bibliography of literature. (VHE) [de

  18. Development of references of anomalies detection on P91 material using Self-Magnetic Leakage Field (SMLF) technique

    Science.gov (United States)

    Husin, Shuib; Afiq Pauzi, Ahmad; Yunus, Salmi Mohd; Ghafar, Mohd Hafiz Abdul; Adilin Sekari, Saiful

    2017-10-01

    This technical paper demonstrates the successful of the application of self-magnetic leakage field (SMLF) technique in detecting anomalies in weldment of a thick P91 materials joint (1 inch thickness). Boiler components such as boiler tubes, stub boiler at penthouse and energy piping such as hot reheat pipe (HRP) and H-balance energy piping to turbine are made of P91 material. P91 is ferromagnetic material, therefore the technique of self-magnetic leakage field (SMLF) is applicable for P91 in detecting anomalies within material (internal defects). The technique is categorized under non-destructive technique (NDT). It is the second passive method after acoustic emission (AE), at which the information on structures radiation (magnetic field and energy waves) is used. The measured magnetic leakage field of a product or component is a magnetic leakage field occurring on the component’s surface in the zone of dislocation stable slipbands under the influence of operational (in-service) or residual stresses or in zones of maximum inhomogeneity of metal structure in new products or components. Inter-granular and trans-granular cracks, inclusion, void, cavity and corrosion are considered types of inhomogeneity and discontinuity in material where obviously the output of magnetic leakage field will be shown when using this technique. The technique does not required surface preparation for the component to be inspected. This technique is contact-type inspection, which means the sensor has to touch or in-contact to the component’s surface during inspection. The results of application of SMLF technique on the developed P91 reference blocks have demonstrated that the technique is practical to be used for anomaly inspection and detection as well as identification of anomalies’ location. The evaluation of this passive self-magnetic leakage field (SMLF) technique has been verified by other conventional non-destructive tests (NDTs) on the reference blocks where simulated

  19. An aggregate method to calibrate the reference point of cumulative prospect theory-based route choice model for urban transit network

    Science.gov (United States)

    Zhang, Yufeng; Long, Man; Luo, Sida; Bao, Yu; Shen, Hanxia

    2015-12-01

    Transit route choice model is the key technology of public transit systems planning and management. Traditional route choice models are mostly based on expected utility theory which has an evident shortcoming that it cannot accurately portray travelers' subjective route choice behavior for their risk preferences are not taken into consideration. Cumulative prospect theory (CPT), a brand new theory, can be used to describe travelers' decision-making process under the condition of uncertainty of transit supply and risk preferences of multi-type travelers. The method to calibrate the reference point, a key parameter to CPT-based transit route choice model, determines the precision of the model to a great extent. In this paper, a new method is put forward to obtain the value of reference point which combines theoretical calculation and field investigation results. Comparing the proposed method with traditional method, it shows that the new method can promote the quality of CPT-based model by improving the accuracy in simulating travelers' route choice behaviors based on transit trip investigation from Nanjing City, China. The proposed method is of great significance to logical transit planning and management, and to some extent makes up the defect that obtaining the reference point is solely based on qualitative analysis.

  20. Modeling of Electric Field Around 100 MVA 150/20 KV Power Transformator Using Charge Simulation Method

    OpenAIRE

    Rachman, Noviadi Arief; Risdiyanto, Agus; Ramdan, Ade

    2013-01-01

    Charge Simulation Method is one of the field theory that can be used as an approach to calculate the electromagnetic distribution on the electrical conductor. This paper discussed electric field modeling around power transformator by using Matlab to find the safety distance. The safe distance threshold of the electric field to human health refers to WHO and SNI was 5 kV/m. The specification of the power transformator was three phases, 150/20 kV, and 100 MVA. The basic concept is to change the...

  1. Reference Model 5 (RM5): Oscillating Surge Wave Energy Converter

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Y. H. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Jenne, D. S. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Thresher, R. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Copping, A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Geerlofs, S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hanna, L. A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-01-01

    This report is an addendum to SAND2013-9040: Methodology for Design and Economic Analysis of Marine Energy Conversion (MEC) Technologies. This report describes an Oscillating Water Column Wave Energy Converter (OSWEC) reference model design in a complementary manner to Reference Models 1-4 contained in the above report. A conceptual design for a taut moored oscillating surge wave energy converter was developed. The design had an annual electrical power of 108 kilowatts (kW), rated power of 360 kW, and intended deployment at water depths between 50 m and 100 m. The study includes structural analysis, power output estimation, a hydraulic power conversion chain system, and mooring designs. The results were used to estimate device capital cost and annual operation and maintenance costs. The device performance and costs were used for the economic analysis, following the methodology presented in SAND2013-9040 that included costs for designing, manufacturing, deploying, and operating commercial-scale MEC arrays up to 100 devices. The levelized cost of energy estimated for the Reference Model 5 OSWEC, presented in this report, was for a single device and arrays of 10, 50, and 100 units, and it enabled the economic analysis to account for cost reductions associated with economies of scale. The baseline commercial levelized cost of energy estimate for the Reference Model 5 device in an array comprised of 10 units is $1.44/kilowatt-hour (kWh), and the value drops to approximately $0.69/kWh for an array of 100 units.

  2. Model for assessing alpha doses for a Reference Japanese Man

    International Nuclear Information System (INIS)

    Kawamura, Hisao

    1993-01-01

    In view of the development of the nuclear fuel cycle in this country, it is urgently important to establish dose assessment models and related human and environmental parameters for long-lived radionuclides. In the current program, intake and body content of actinides (Pu, Th, U) and related alpha-emitting nuclides (Ra and daughters) have been studied as well as physiological aspects of Reference Japanese Man as the basic model of man for dosimetry. The ultimate object is to examine applicability of the existing models particularly recommended by the ICRP for workers to members of the public. The result of an interlaboratory intercomparison of 239 Pu + 240 Pu determination including our result was published. Alpha-spectrometric determinations of 226 Ra in bone yielded repesentative bone concentration level in Tokyo and Ra-Ca O.R. (bone-diet) which appear consistent with the literature value for Sapporo and Kyoto by Ohno using a Rn emanation method. Specific effective energies for alpha radiation from 226 Ra and daughters were calculated using the ICRP dosimetric model for bone incorporating masses of source and target organs of Reference Japanese Man. Reference Japanese data including the adult, adolescent, child and infant of both sexes was extensively and intensively studied by Tanaka as part of the activities of the ICRP Task Group on Reference Man Revision. Normal data for the physical measurements, mass and dimension of internal organs and body surfaces and some of the body composition were analysed viewing the nutritional data in the Japanese population. Some of the above works are to be continued. (author)

  3. Technical note: A simple approach for efficient collection of field reference data for calibrating remote sensing mapping of northern wetlands

    Science.gov (United States)

    Gålfalk, Magnus; Karlson, Martin; Crill, Patrick; Bousquet, Philippe; Bastviken, David

    2018-03-01

    The calibration and validation of remote sensing land cover products are highly dependent on accurate field reference data, which are costly and practically challenging to collect. We describe an optical method for collection of field reference data that is a fast, cost-efficient, and robust alternative to field surveys and UAV imaging. A lightweight, waterproof, remote-controlled RGB camera (GoPro HERO4 Silver, GoPro Inc.) was used to take wide-angle images from 3.1 to 4.5 m in altitude using an extendable monopod, as well as representative near-ground (wetland mapping. The method uses common non-expensive equipment, does not require special skills or training, and is facilitated by a step-by-step manual that is included in the Supplement. Over time a global ground cover database can be built that can be used as reference data for studies of non-forested wetlands from satellites such as Sentinel 1 and 2 (10 m pixel size).

  4. Reference analysis of the signal + background model in counting experiments

    Science.gov (United States)

    Casadei, D.

    2012-01-01

    The model representing two independent Poisson processes, labelled as ``signal'' and ``background'' and both contributing additively to the total number of counted events, is considered from a Bayesian point of view. This is a widely used model for the searches of rare or exotic events in presence of a background source, as for example in the searches performed by high-energy physics experiments. In the assumption of prior knowledge about the background yield, a reference prior is obtained for the signal alone and its properties are studied. Finally, the properties of the full solution, the marginal reference posterior, are illustrated with few examples.

  5. Z3 model of Saturns magnetic field and the Pioneer 11 vector helium magnetometer observations

    International Nuclear Information System (INIS)

    Connerney, J.E.P.; Acuna, M.H.; Ness, N.F.

    1984-05-01

    Magnetic field observations obtained by the Pioneer 11 vector helium magnetometer are compared with the Z(sub 3) model magnetic field. These Pioneer 11 observations, obtained at close-in radial distances, constitute an important and independent test of the Z(sub 3) zonal harmonic model, which was derived from Voyager 1 and Voyager 2 fluxgate magnetometer observations. Differences between the Pioneer 11 magnetometer and the Z(sub 3) model field are found to be small (approximately 1%) and quantitatively consistent with the expected instrumental accuracy. A detailed examination of these differences in spacecraft payload coordinates shows that they are uniquely associated with the instrument frame of reference and operation. A much improved fit to the Pioneer 11 observations is obtained by rotation of the instrument coordinate system about the spacecraft spin axis by 1.4 degree. With this adjustment, possibly associated with an instrumental phase lag or roll attitude error, the Pioneer 11 vector helium magnetometer observations are fully consistent with the Voyager Z(sub 3) model

  6. Reference Priors for the General Location-Scale Model

    NARCIS (Netherlands)

    Fernández, C.; Steel, M.F.J.

    1997-01-01

    The reference prior algorithm (Berger and Bernardo 1992) is applied to multivariate location-scale models with any regular sampling density, where we establish the irrelevance of the usual assumption of Normal sampling if our interest is in either the location or the scale. This result immediately

  7. A COUPLED 2 × 2D BABCOCK–LEIGHTON SOLAR DYNAMO MODEL. II. REFERENCE DYNAMO SOLUTIONS

    International Nuclear Information System (INIS)

    Lemerle, Alexandre; Charbonneau, Paul

    2017-01-01

    In this paper we complete the presentation of a new hybrid 2 × 2D flux transport dynamo (FTD) model of the solar cycle based on the Babcock–Leighton mechanism of poloidal magnetic field regeneration via the surface decay of bipolar magnetic regions (BMRs). This hybrid model is constructed by allowing the surface flux transport (SFT) simulation described in Lemerle et al. to provide the poloidal source term to an axisymmetric FTD simulation defined in a meridional plane, which in turn generates the BMRs required by the SFT. A key aspect of this coupling is the definition of an emergence function describing the probability of BMR emergence as a function of the spatial distribution of the internal axisymmetric magnetic field. We use a genetic algorithm to calibrate this function, together with other model parameters, against observed cycle 21 emergence data. We present a reference dynamo solution reproducing many solar cycle characteristics, including good hemispheric coupling, phase relationship between the surface dipole and the BMR-generating internal field, and correlation between dipole strength at cycle maximum and peak amplitude of the next cycle. The saturation of the cycle amplitude takes place through the quenching of the BMR tilt as a function of the internal field. The observed statistical scatter about the mean BMR tilt, built into the model, acts as a source of stochasticity which dominates amplitude fluctuations. The model thus can produce Dalton-like epochs of strongly suppressed cycle amplitude lasting a few cycles and can even shut off entirely following an unfavorable sequence of emergence events.

  8. A COUPLED 2 × 2D BABCOCK–LEIGHTON SOLAR DYNAMO MODEL. II. REFERENCE DYNAMO SOLUTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Lemerle, Alexandre; Charbonneau, Paul, E-mail: lemerle@astro.umontreal.ca, E-mail: paulchar@astro.umontreal.ca [Département de physique, Université de Montréal, 2900 Boulevard Édouard-Montpetit, Montréal, QC, H3T 1J4 (Canada)

    2017-01-10

    In this paper we complete the presentation of a new hybrid 2 × 2D flux transport dynamo (FTD) model of the solar cycle based on the Babcock–Leighton mechanism of poloidal magnetic field regeneration via the surface decay of bipolar magnetic regions (BMRs). This hybrid model is constructed by allowing the surface flux transport (SFT) simulation described in Lemerle et al. to provide the poloidal source term to an axisymmetric FTD simulation defined in a meridional plane, which in turn generates the BMRs required by the SFT. A key aspect of this coupling is the definition of an emergence function describing the probability of BMR emergence as a function of the spatial distribution of the internal axisymmetric magnetic field. We use a genetic algorithm to calibrate this function, together with other model parameters, against observed cycle 21 emergence data. We present a reference dynamo solution reproducing many solar cycle characteristics, including good hemispheric coupling, phase relationship between the surface dipole and the BMR-generating internal field, and correlation between dipole strength at cycle maximum and peak amplitude of the next cycle. The saturation of the cycle amplitude takes place through the quenching of the BMR tilt as a function of the internal field. The observed statistical scatter about the mean BMR tilt, built into the model, acts as a source of stochasticity which dominates amplitude fluctuations. The model thus can produce Dalton-like epochs of strongly suppressed cycle amplitude lasting a few cycles and can even shut off entirely following an unfavorable sequence of emergence events.

  9. Development of a long term macro econometric model for strategic analysis and cost assessments in nuclear R and D fields

    International Nuclear Information System (INIS)

    Mankin, Shuichi; Yamazaki, Shigeki.

    1985-11-01

    A Long Term Macro Econometric Model (LTMEMO) has been developed for the purpose of generating economic scenarios for strategic analysis and for cost assessments of technologies in the field of nuclear research and development. The program system of the model is composed of such sub-programs as related social and economic statistic data base and its treatment program, identification and estimation programs of various econometric functions, simulation programs for future projections, and a reference econometric model program. The reference econometric model in the program system would be improved and modified easily by using data base and other sub-programs as the purpose of data retrieval, application of economic hypothesis, and scenario generation. The reference model belongs to a category of such standard types as macro-econometric, deterministic, and descriptive one, however, it was deviated based on the combination of Keynesian theories and Neo-classical theories and was modified by system engineering aspects. The model obtained good performances in such various econometric tests as statistical examinations in parameter estimation of each functions and so called partial tests, total tests, and final tests. Macro economic scenarios α and β, long term projections through 2030 of macro economy in our country were evaluated appropriately by this model. This report describes the process in the development of the model from needs of econometric model in nuclear fields to examples of economic scenarios generated by this model. Some consideration are taken into descriptions on the deviation of each functions and on the application of economic theories for practical use of this program system at the time of modification and improvements of the reference model. (author)

  10. The CHAOS-4 geomagnetic field model

    DEFF Research Database (Denmark)

    Olsen, Nils; Lühr, H.; Finlay, Chris

    2014-01-01

    We present CHAOS-4, a new version in the CHAOS model series, which aims to describe the Earth's magnetic field with high spatial and temporal resolution. Terms up to spherical degree of at least n = 85 for the lithospheric field, and up to n = 16 for the time-varying core field are robustly...... to the core field, but the high-degree lithospheric field is regularized for n > 85. CHAOS-4 model is derived by merging two submodels: its low-degree part has been derived using similar model parametrization and data sets as used for previous CHAOS models (but of course including more recent data), while its...

  11. PI controller based model reference adaptive control for nonlinear

    African Journals Online (AJOL)

    user

    Keywords: Model Reference Adaptive Controller (MRAC), Artificial Neural ... attention, and many new approaches have been applied to practical process .... effectiveness of proposed method, it is compared with the simulation results of the ...

  12. Speed Sensorless Control of PMSM using Model Reference Adaptive System and RBFN

    OpenAIRE

    Wei Gao; Zhirong Guo

    2013-01-01

    In the speed sensorless vector control system, the amended method of estimating the rotor speed about model reference adaptive system (MRAS) based on radial basis function neural network (RBFN) for PMSM sensorless vector control system was presented. Based on the PI regulator, the radial basis function neural network which is more prominent learning efficiency and performance is combined with MRAS. The reference model and the adjust model are the PMSM itself and the PMSM current, respectively...

  13. Model of unified gauge fields

    International Nuclear Information System (INIS)

    Leite Lopes, J.

    1998-04-01

    In this work, we discuss the physical ideas which represents the basis for the unified gauge field model. Despite of the difficulties that we presently have for embodying in a natural manner muons and hadrons in that model, we have the feeling that we are on the way which seems to lead to the construction of a theory in which the Maxwell electromagnetic field and the Fermi weak interaction field are manifestations of a unique subjacent physical entity - the unified gauge fields. (author)

  14. Children and adults exposed to electromagnetic fields at the ICNIRP reference levels: theoretical assessment of the induced peak temperature increase

    Energy Technology Data Exchange (ETDEWEB)

    Bakker, J F; Paulides, M M; Van Rhoon, G C [Erasmus MC-Daniel den Hoed Cancer Center, Department of Radiation Oncology, Section Hyperthermia, PO Box 5201, NL-3008 AE, Rotterdam (Netherlands); Neufeld, E; Christ, A; Kuster, N, E-mail: j.bakker@erasmusmc.nl [Foundation for Research on Information Technologies in Society (IT' IS) (Switzerland)

    2011-08-07

    To avoid potentially adverse health effects of electromagnetic fields (EMF), the International Commission on Non-Ionizing Radiation Protection (ICNIRP) has defined EMF reference levels. Restrictions on induced whole-body-averaged specific absorption rate (SAR{sub wb}) are provided to keep the whole-body temperature increase (T{sub body,incr}) under 1 deg. C during 30 min. Additional restrictions on the peak 10 g spatial-averaged SAR (SAR{sub 10g}) are provided to prevent excessive localized tissue heating. The objective of this study is to assess the localized peak temperature increase (T{sub incr,max}) in children upon exposure at the reference levels. Finite-difference time-domain modeling was used to calculate T{sub incr,max} in six children and two adults exposed to orthogonal plane-wave configurations. We performed a sensitivity study and Monte Carlo analysis to assess the uncertainty of the results. Considering the uncertainties in the model parameters, we found that a peak temperature increase as high as 1 deg. C can occur for worst-case scenarios at the ICNIRP reference levels. Since the guidelines are deduced from temperature increase, we used T{sub incr,max} as being a better metric to prevent excessive localized tissue heating instead of localized peak SAR. However, we note that the exposure time should also be considered in future guidelines. Hence, we advise defining limits on T{sub incr,max} for specified durations of exposure.

  15. Improved model of the Earth's gravitational field: GEM-T1

    International Nuclear Information System (INIS)

    Marsh, J.G.; Lerch, F.J.; Christodoulidis, D.C.

    1987-07-01

    Goddard Earth Model T1 (GEM-T1), which was developed from an analysis of direct satellite tracking observations, is the first in a new series of such models. GEM-T1 is complete to degree and order 36. It was developed using consistent reference parameters and extensive earth and ocean tidal models. It was simultaneously solved for gravitational and tidal terms, earth orientation parameters, and the orbital parameters of 580 individual satellite arcs. The solution used only satellite tracking data acquired on 17 different satellites and is predominantly based upon the precise laser data taken by third generation systems. In all, 800,000 observations were used. A major improvement in field accuracy was obtained. For marine geodetic applications, long wavelength geoidal modeling is twice as good as in earlier satellite-only GEM models. Orbit determination accuracy has also been substantially advanced over a wide range of satellites that have been tested

  16. Validation of IRDFF in 252Cf Standard and IRDF-2002 Reference Neutron Fields

    Directory of Open Access Journals (Sweden)

    Simakov Stanislav

    2016-01-01

    Full Text Available The results of validation of the latest release of International Reactor Dosimetry and Fusion File, IRDFF-1.03, in the standard 252Cf(s.f. and reference 235U(nth,f neutron benchmark fields are presented. The spectrum-averaged cross sections were shown to confirm IRDFF-1.03 in the 252Cf standard spontaneous fission spectrum; that was not the case for the current recommended spectra for 235U(nth,f. IRDFF was also validated in the spectra of the research reactor facilities ISNF, Sigma-Sigma and YAYOI, which are available in the IRDF-2002 collection. The ISNF facility was re-simulated to remove unphysical oscillations in the spectrum. IRDFF-1.03 was shown to reproduce reasonably well the spectrum-averaged data measured in these fields except for the case of YAYOI.

  17. Teaching methodology for modeling reference evapotranspiration with artificial neural networks

    OpenAIRE

    Martí, Pau; Pulido Calvo, Inmaculada; Gutiérrez Estrada, Juan Carlos

    2015-01-01

    [EN] Artificial neural networks are a robust alternative to conventional models for estimating different targets in irrigation engineering, among others, reference evapotranspiration, a key variable for estimating crop water requirements. This paper presents a didactic methodology for introducing students in the application of artificial neural networks for reference evapotranspiration estimation using MatLab c . Apart from learning a specific application of this software wi...

  18. A reference model for space data system interconnection services

    Science.gov (United States)

    Pietras, John; Theis, Gerhard

    1993-01-01

    The widespread adoption of standard packet-based data communication protocols and services for spaceflight missions provides the foundation for other standard space data handling services. These space data handling services can be defined as increasingly sophisticated processing of data or information received from lower-level services, using a layering approach made famous in the International Organization for Standardization (ISO) Open System Interconnection Reference Model (OSI-RM). The Space Data System Interconnection Reference Model (SDSI-RM) incorporates the conventions of the OSIRM to provide a framework within which a complete set of space data handling services can be defined. The use of the SDSI-RM is illustrated through its application to data handling services and protocols that have been defined by, or are under consideration by, the Consultative Committee for Space Data Systems (CCSDS).

  19. From Landau's hydrodynamical model to field theory model to field theory models of multiparticle production: a tribute to Peter

    International Nuclear Information System (INIS)

    Cooper, F.

    1996-01-01

    We review the assumptions and domain of applicability of Landau's Hydrodynamical Model. By considering two models of particle production, pair production from strong electric fields and particle production in the linear σ model, we demonstrate that many of Landau's ideas are verified in explicit field theory calculations

  20. Development of the neutron reference calibration field using a 252Cf standard source surrounded with PMMA moderators

    International Nuclear Information System (INIS)

    Yoshida, T.; Kanai, K.; Tsujimura, N.

    2002-01-01

    The authors developed the neutron reference calibration fields using a 252 Cf standard source surrounded with PMMA moderators at the Japan Nuclear Cycle Development (JNC), Tokai Works. The moderators are co-axial, hollow cylinders made of lead-contained PMMA with a thickness of 13.5, 35.0, 59.5 and 77.0mm, and the 252 Cf source is guided to the geometric center of moderators by the pneumatic system. These fields can provide the moderated neutron spectra very similar to those encountered around the globe-boxes of the fabrication process of MOX (PuO 2 -UO 2 mixed oxide) fuel. The neutron energy spectrum at the reference calibration point was evaluated from the calculations by MCNP4B and the measurements by the INS-type Bonner multi-sphere spectrometer and the hydrogen-filled proportional counters. The calculated neutron spectra were in good agreements with the measured ones. These fields were characterized in terms of the neutron fluence rate, spectral composition and ambient dose equivalent rate, and have served for the response-characterization of various neutron survey instruments

  1. Building analytical three-field cosmological models

    Energy Technology Data Exchange (ETDEWEB)

    Santos, J.R.L. [Universidade de Federal de Campina Grande, Unidade Academica de Fisica, Campina Grande, PB (Brazil); Moraes, P.H.R.S. [ITA-Instituto Tecnologico de Aeronautica, Sao Jose dos Campos, SP (Brazil); Ferreira, D.A. [Universidade de Federal de Campina Grande, Unidade Academica de Fisica, Campina Grande, PB (Brazil); Universidade Federal da Paraiba, Departamento de Fisica, Joao Pessoa, PB (Brazil); Neta, D.C.V. [Universidade de Federal de Campina Grande, Unidade Academica de Fisica, Campina Grande, PB (Brazil); Universidade Estadual da Paraiba, Departamento de Fisica, Campina Grande, PB (Brazil)

    2018-02-15

    A difficult task to deal with is the analytical treatment of models composed of three real scalar fields, as their equations of motion are in general coupled and hard to integrate. In order to overcome this problem we introduce a methodology to construct three-field models based on the so-called ''extension method''. The fundamental idea of the procedure is to combine three one-field systems in a non-trivial way, to construct an effective three scalar field model. An interesting scenario where the method can be implemented is with inflationary models, where the Einstein-Hilbert Lagrangian is coupled with the scalar field Lagrangian. We exemplify how a new model constructed from our method can lead to non-trivial behaviors for cosmological parameters. (orig.)

  2. Adaptive control for a PWR using a self-tuning reference model concept

    International Nuclear Information System (INIS)

    Miley, G.H.; Park, G.T.; Kim, B.S.

    1992-01-01

    Possible applications of an adaptive control method to a pressurized-water reactor nuclear power plant are investigated. The self-tuning technique with a reference model concept is employed. This control algorithm is developed by combining the self-tuning controller with the model reference adaptive control. This approach overcomes the difficulties in choosing the appropriate weighting polynomials in the cost function of the self-tuning control

  3. An internal reference model-based PRF temperature mapping method with Cramer-Rao lower bound noise performance analysis.

    Science.gov (United States)

    Li, Cheng; Pan, Xinyi; Ying, Kui; Zhang, Qiang; An, Jing; Weng, Dehe; Qin, Wen; Li, Kuncheng

    2009-11-01

    The conventional phase difference method for MR thermometry suffers from disturbances caused by the presence of lipid protons, motion-induced error, and field drift. A signal model is presented with multi-echo gradient echo (GRE) sequence using a fat signal as an internal reference to overcome these problems. The internal reference signal model is fit to the water and fat signals by the extended Prony algorithm and the Levenberg-Marquardt algorithm to estimate the chemical shifts between water and fat which contain temperature information. A noise analysis of the signal model was conducted using the Cramer-Rao lower bound to evaluate the noise performance of various algorithms, the effects of imaging parameters, and the influence of the water:fat signal ratio in a sample on the temperature estimate. Comparison of the calculated temperature map and thermocouple temperature measurements shows that the maximum temperature estimation error is 0.614 degrees C, with a standard deviation of 0.06 degrees C, confirming the feasibility of this model-based temperature mapping method. The influence of sample water:fat signal ratio on the accuracy of the temperature estimate is evaluated in a water-fat mixed phantom experiment with an optimal ratio of approximately 0.66:1. (c) 2009 Wiley-Liss, Inc.

  4. The Swarm Initial Field Model for the 2014 Geomagnetic Field

    Science.gov (United States)

    Olsen, Nils; Hulot, Gauthier; Lesur, Vincent; Finlay, Christopher C.; Beggan, Ciaran; Chulliat, Arnaud; Sabaka, Terence J.; Floberghagen, Rune; Friis-Christensen, Eigil; Haagmans, Roger

    2015-01-01

    Data from the first year of ESA's Swarm constellation mission are used to derive the Swarm Initial Field Model (SIFM), a new model of the Earth's magnetic field and its time variation. In addition to the conventional magnetic field observations provided by each of the three Swarm satellites, explicit advantage is taken of the constellation aspect by including east-west magnetic intensity gradient information from the lower satellite pair. Along-track differences in magnetic intensity provide further information concerning the north-south gradient. The SIFM static field shows excellent agreement (up to at least degree 60) with recent field models derived from CHAMP data, providing an initial validation of the quality of the Swarm magnetic measurements. Use of gradient data improves the determination of both the static field and its secular variation, with the mean misfit for east-west intensity differences between the lower satellite pair being only 0.12 nT.

  5. Modeling of Electric Field Around 100 MVA 150/20 kV Power Transformator using Charge Simulation Method

    Directory of Open Access Journals (Sweden)

    Noviadi Arief Rachman

    2013-07-01

    Full Text Available Charge Simulation Method is one of the field theory that can be used as an approach to calculate the electromagnetic distribution on the electrical conductor. This paper discussed electric field modeling around power transformator by using Matlab to find the safety distance. The safe distance threshold of the electric field to human health refers to WHO and SNI was 5 kV/m. The specification of the power transformator was three phases, 150/20 kV, and 100 MVA. The basic concept is to change the distribution charge on the conductor or dielectric polarization charge with a set of discrete fictitious charge. The value of discrete fictitious charge was equivalent to the potential value of the conductor, and became a reference to calculate the electric field around the surface contour of the selected power transformator. The measurement distance was 5 meter on each side of the transformator surface. The results showed that the magnitude of the electric field at the front side was 5541 V/m, exceeding the safety limits.

  6. Modelo de referência para estruturar o Seis Sigma nas organizações Reference model to structure the Six Sigma in organizations

    Directory of Open Access Journals (Sweden)

    Adriana Barbosa Santos

    2008-04-01

    Full Text Available Este artigo apresenta o modelo de referência para estruturar o Seis Sigma, o qual é resultante da incorporação de teorias que contribuem para aumentar o potencial estratégico do Seis Sigma no sentido de incrementar o desempenho organizacional. Em sua proposta, o modelo de referência engloba um direcionamento sobre certos requisitos primordiais para o sucesso do programa Seis Sigma. A base teórica de sustentação do modelo de referência foi construída a partir de estudos sobre a influência dos seguintes fatores: orientação estratégica e alinhamento estratégico; medição e gerenciamento do desempenho organizacional; uso de estatística (pensamento estatístico; capacitação/especialização de pessoas; implementação e gerenciamento de projetos; e uso de tecnologia de informação. Complementando a proposição do modelo, o artigo traz evidências empíricas acerca da contribuição dos fatores identificados na formulação do modelo de referência, expondo resultados decorrentes de estudos de caso realizados em quatro subsidiárias brasileiras de multinacionais de grande porte. A análise dos dados forneceu evidências positivas de que os fatores mencionados influenciam de forma efetiva o sucesso e a consolidação do Seis Sigma nas empresas estudadas.This paper introduces the reference model to structure Six Sigma. This model is a result of theory incorporation that contributes to increase the strategic power of Six Sigma for improving businesses performance. Reference model proposal points out certain primordial requirements for de Six Sigma program success. The theoretical basis to sustain the reference model was supported in studies about the influence of critical factors such as: strategic orientation and strategic alignment; business performance measurement; statistical approach (statistical thinking; people training; project implementation; and information technology use. Complementing the model proposition, this paper

  7. Data requirements for integrated near field models

    International Nuclear Information System (INIS)

    Wilems, R.E.; Pearson, F.J. Jr.; Faust, C.R.; Brecher, A.

    1981-01-01

    The coupled nature of the various processes in the near field require that integrated models be employed to assess long term performance of the waste package and repository. The nature of the integrated near field models being compiled under the SCEPTER program are discussed. The interfaces between these near field models and far field models are described. Finally, near field data requirements are outlined in sufficient detail to indicate overall programmatic guidance for data gathering activities

  8. Fit Gap Analysis – The Role of Business Process Reference Models

    Directory of Open Access Journals (Sweden)

    Dejan Pajk

    2013-12-01

    Full Text Available Enterprise resource planning (ERP systems support solutions for standard business processes such as financial, sales, procurement and warehouse. In order to improve the understandability and efficiency of their implementation, ERP vendors have introduced reference models that describe the processes and underlying structure of an ERP system. To select and successfully implement an ERP system, the capabilities of that system have to be compared with a company’s business needs. Based on a comparison, all of the fits and gaps must be identified and further analysed. This step usually forms part of ERP implementation methodologies and is called fit gap analysis. The paper theoretically overviews methods for applying reference models and describes fit gap analysis processes in detail. The paper’s first contribution is its presentation of a fit gap analysis using standard business process modelling notation. The second contribution is the demonstration of a process-based comparison approach between a supply chain process and an ERP system process reference model. In addition to its theoretical contributions, the results can also be practically applied to projects involving the selection and implementation of ERP systems.

  9. A quantitative analysis of faulty EPCs in the SAP reference model

    NARCIS (Netherlands)

    Mendling, J.; Moser, M.; Neumann, G.; Verbeek, H.M.W.; Dongen, van B.F.; Aalst, van der W.M.P.

    2006-01-01

    The SAP reference model contains more than 600 non-trivial process models expressed in terms of Event-driven Process Chains (EPCs). We have automatically translated these EPCs into YAWL models and analyzed these models usingWofYAWL, a veri¯cation tool based on Petri nets. We discovered that at least

  10. DTU candidate field models for IGRF-12 and the CHAOS-5 geomagnetic field model

    DEFF Research Database (Denmark)

    Finlay, Chris; Olsen, Nils; Tøffner-Clausen, Lars

    2015-01-01

    We present DTU’s candidate field models for IGRF-12 and the parent field model from which they were derived,CHAOS-5. Ten months of magnetic field observations from ESA’s Swarm mission, together with up-to-date ground observatory monthly means, were used to supplement the data sources previously u...... been documented, but the 2013 pulse has only recently been identified. The spatial signature of the 2013pulse at the core surface, under the Atlantic sector where it is strongest, is well correlated with the 2006 pulse, but anti-correlated with the 2009 pulse....

  11. A Java Reference Model of Transacted Memory for Smart Cards

    NARCIS (Netherlands)

    Poll, Erik; Hartel, Pieter H.; de Jong, Eduard

    Transacted Memory offers persistence, undoability and auditing. We present a Java/JML Reference Model of the Transacted Memory system on the basis of our earlier separate Z model and C implementation. We conclude that Java/JML combines the advantages of a high level specification in the JML part

  12. A Java Reference Model of Transacted Memory for Smart Cards

    NARCIS (Netherlands)

    Poll, Erik; Hartel, Pieter H.; de Jong, Eduard

    2002-01-01

    Transacted Memory offers persistence, undoability and auditing. We present a Java/JML Reference Model of the Transacted Memory system on the basis of our earlier separate Z model and C implementation. We conclude that Java/JML combines the advantages of a high level specification in the JML part

  13. Assessment of inhomogeneous ELF magnetic field exposures

    International Nuclear Information System (INIS)

    Leitgeb, N.; Cech, R.; Schroettner, J.

    2008-01-01

    In daily life as well as at workplaces, exposures to inhomogeneous magnetic fields become very frequent. This makes easily applicable compliance assessment methods increasingly important. Reference levels have been defined linking basic restrictions to levels of homogeneous fields at worst-case exposure conditions. If reference levels are met, compliance with basic restrictions can be assumed. If not, further investigations could still prove compliance. Because of the lower induction efficiency, inhomogeneous magnetic fields such as from electric appliances could be allowed exceeding reference levels. To easily assess inhomogeneous magnetic fields, a quick and flexible multi-step assessment procedure is proposed. On the basis of simulations with numerical, anatomical human models reference factors were calculated elevating reference levels to link hot-spot values measured at source surfaces to basic limits and allowing accounting for different source distance, size, orientation and position. Compliance rules are proposed minimising assessment efforts. (authors)

  14. Implementing an inclusive staffing model for today's reference services a practical guide for librarians

    CERN Document Server

    Nims, Julia K; Stevens, Robert

    2013-01-01

    Reference service remains a core function of modern libraries. However, how and where we provide assistance has evolved with changing technologies and the shifting habits and preferences of our users. One way libraries can provide the on-demand, in-person assistance while managing and developing new services and resources that will benefit current and future users is to reconsider how their reference points and services are staffed and adopt a staff-based reference model. In Implementing an Inclusive Staffing Model for Today's Reference Services, Nims, Storm, and Stevens describe step-by-step

  15. The CHAOS-4 Geomagnetic Field Model

    DEFF Research Database (Denmark)

    Olsen, Nils; Finlay, Chris; Lühr, H.

    We present CHAOS-4, a new version in the CHAOS model series, which aims at describing the Earth's magnetic field with high spatial resolution (terms up to spherical degree n=90 for the crustal field, and up to n=16 for the time-varying core field are robustly determined) and high temporal...... between the coordinate systems of the vector magnetometer and of the star sensor providing attitude information). The final CHAOS-4 model is derived by merging two sub-models: its low-degree part has been obtained using similar model parameterization and data sets as used for previous CHAOS models (but...

  16. RESICALC: Magnetic field modeling program

    International Nuclear Information System (INIS)

    Silva, J.M.

    1992-12-01

    RESICALC, Version 1.0, is a Microsoft Windows application that describes the magnetic field environment produced by user-defined arrays of transmission lines, distribution lines, and custom conductors. These arrays simulate specific situations that may be encountered in real-world community settings. RESICALC allows the user to define an area or ''world'' that contains the transmission and/or distribution lines, user-defined conductors, and locations of residences. The world contains a ''reference grid'' within which RESICALC analyzes the magnetic field environment due to all conductors within the world. Unique physical parameters (e.g., conductor height and spacing) and operating characteristics can be assigned to all electrical conductors. RESICALC's output is available for the x, y, z axis separately, the resultant (the three axes added in quadrature), and the major axis, each in three possible formats: a three-dimensional map of the magnetic field, two dimensional-contours, and as a table with statistical values. All formats may be printed, accompanied by a three-dimensional view of the world the user has drawn. The view of the world and the corresponding three-dimensional field map may be adjusted to the elevation and rotation angle of the user's preference

  17. Ørsted Initial Field Model

    DEFF Research Database (Denmark)

    Olsen, Nils; Holme, R.; Hulot, G.

    2000-01-01

    Magnetic measurements taken by the Orsted satellite during geomagnetic quiet conditions around January 1, 2000 have been used to derive a spherical harmonic model of the Earth's magnetic field for epoch 2000.0. The maximum degree and order of the model is 19 for internal, and 2 for external, source...... fields; however, coefficients above degree 14 may not be robust. Such a detailed model exists for only one previous epoch, 1980. Achieved rms misfit is ... to the Orsted mission, this model supercedes IGRF 2000....

  18. MOX fuel effective behaviour modeling by a micro-mechanical nonuniform transformation field analysis

    International Nuclear Information System (INIS)

    Largenton, R.

    2012-01-01

    The objective of this research thesis is to develop a modelling by scale change, based on the NTFA approach (Non uniform Transformation Field Analysis). These developments have been achieved on three-dimensional structures which are representative of the MOX fuel, and for local visco-elastic ageing behaviour with free deformations. First, the MOX fuel is represented by using existing methods to process and segment 2D experimental images. 2D information has been upgraded in 3D by a stereo-logic Saltykov method. Tools have been developed to represent and discretize (periodic 3D grid generator) a particulate multiphase composite representative of MOX. Developments made on the NTFA model and on the three-phase particulate composite have been theoretically and numerically studied. The model has then been validated by comparison with reference calculations performed in full field for the effective behaviour as well as for local fields for different test types (imposed strain rate, creep, relaxation, rotating). The approach is then compared with a recently developed homogenisation method: the semi-analytical 'incremental Mori-Tanka' model. Theoretical similarities are outlined. These methods are very fast in terms of CPU time, but the NTFA method remains the one giving the most information, and the most precise, but requires a more important preliminary work (mode identification) [fr

  19. Field studies and modeling of chemical processes in the unsaturated zone

    International Nuclear Information System (INIS)

    Polzer, W.L.; Fuentes, H.R.

    1985-01-01

    Technical assistance is being provided to Nuclear Materials Safety and Safeguards of the Nuclear Regulatory Commission to evaluate the validity of several guidelines listed in 10 CFR Part 61 for the future burial of low-level radioactive waste. Those guidelines include the requirement that the burial site shall be capable of being modeled. Both laboratory- and field-scale studies are being conducted under unsaturated moisture conditions and under steady-state and unsteady-state flow conditions. This paper reviews the kinds of present experiments in low-level radioactive waste disposal in development at the Los Alamos National Laboratory. Major emphasis is on some of the initial analyses of data for laboratory sorption experiments and for field transport tests. Brief reference is made to leaching and transport studies. Laboratory batch equilibrium sorption studies suggest that adsorption of nonconservative tracers can be described in terms of two empirical constants; one gives an indication of the average K/sub d/ for all adsorption sites and the other gives an indication of the spread of individual K/sub d/'s about the average K/sub d/. This information can be translated into a ''chemical dispersion'' under dynamic flow and equilibrium sorption conditions that is in addition to the traditionally accepted physical dispersion. Laboratory nonequilibrium sorption studies suggest that nonequilibrium models may be needed to model the transport of the nonconservative tracers cobalt and cesium; equilibrium models should be suitable to model strontium transport. Analyses from field-scale studies indicate that conservative tracers can reasonably be modeled with a one-dimensional advective-dispersive equation for steady flow. 12 figs., 1 tab

  20. An image-based skeletal tissue model for the ICRP reference newborn

    Energy Technology Data Exchange (ETDEWEB)

    Pafundi, Deanna; Lee, Choonsik; Bolch, Wesley [Department of Nuclear and Radiological Engineering, University of Florida, Gainesville, FL (United States); Watchman, Christopher; Bourke, Vincent [Department of Radiation Oncology, University of Arizona, Tucson, AZ (United States); Aris, John [Department of Anatomy and Cell Biology, University of Florida, Gainesville, FL (United States); Shagina, Natalia [Urals Research Center for Radiation Medicine, Chelyabinsk (Russian Federation); Harrison, John; Fell, Tim [Radiation Protection Division, Health Protection Agency, Chilton (United Kingdom)], E-mail: wbolch@ufl.edu

    2009-07-21

    Hybrid phantoms represent a third generation of computational models of human anatomy needed for dose assessment in both external and internal radiation exposures. Recently, we presented the first whole-body hybrid phantom of the ICRP reference newborn with a skeleton constructed from both non-uniform rational B-spline and polygon-mesh surfaces (Lee et al 2007 Phys. Med. Biol. 52 3309-33). The skeleton in that model included regions of cartilage and fibrous connective tissue, with the remainder given as a homogenous mixture of cortical and trabecular bone, active marrow and miscellaneous skeletal tissues. In the present study, we present a comprehensive skeletal tissue model of the ICRP reference newborn to permit a heterogeneous representation of the skeleton in that hybrid phantom set-both male and female-that explicitly includes a delineation of cortical bone so that marrow shielding effects are correctly modeled for low-energy photons incident upon the newborn skeleton. Data sources for the tissue model were threefold. First, skeletal site-dependent volumes of homogeneous bone were obtained from whole-cadaver CT image analyses. Second, selected newborn bone specimens were acquired at autopsy and subjected to micro-CT image analysis to derive model parameters of the marrow cavity and bone trabecular 3D microarchitecture. Third, data given in ICRP Publications 70 and 89 were selected to match reference values on total skeletal tissue mass. Active marrow distributions were found to be in reasonable agreement with those given previously by the ICRP. However, significant differences were seen in total skeletal and site-specific masses of trabecular and cortical bone between the current and ICRP newborn skeletal tissue models. The latter utilizes an age-independent ratio of 80%/20% cortical and trabecular bone for the reference newborn. In the current study, a ratio closer to 40%/60% is used based upon newborn CT and micro-CT skeletal image analyses. These changes in

  1. Mean-field models and exotic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Bender, M; Buervenich, T; Maruhn, J A; Greiner, W [Inst. fuer Theoretische Physik, Univ. Frankfurt (Germany); Rutz, K [Inst. fuer Theoretische Physik, Univ. Frankfurt (Germany); [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Reinhard, P G [Inst. fuer Theoretische Physik, Univ. Erlangen (Germany)

    1998-06-01

    We discuss two widely used nuclear mean-field models, the relativistic mean-field model and the (nonrelativistic) Skyrme-Hartree-Fock model, and their capability to describe exotic nuclei. Test cases are superheavy nuclei and neutron-rich Sn isotopes. New information in this regime helps to fix hitherto loosely determined aspects of the models. (orig.)

  2. Mean-field models and exotic nuclei

    International Nuclear Information System (INIS)

    Bender, M.; Buervenich, T.; Maruhn, J.A.; Greiner, W.; Rutz, K.; Reinhard, P.G.

    1998-01-01

    We discuss two widely used nuclear mean-field models, the relativistic mean-field model and the (nonrelativistic) Skyrme-Hartree-Fock model, and their capability to describe exotic nuclei. Test cases are superheavy nuclei and neutron-rich Sn isotopes. New information in this regime helps to fix hitherto loosely determined aspects of the models. (orig.)

  3. Phase Field Modeling Using PetIGA

    KAUST Repository

    Vignal, Philippe

    2013-06-01

    Phase field modeling has become a widely used framework in the computational material science community. Its ability to model different problems by defining appropriate phase field parameters and relating it to a free energy functional makes it highly versatile. Thermodynamically consistent partial differential equations can then be generated by assuming dissipative dynamics, and setting up the problem as one of minimizing this free energy. The equations are nonetheless challenging to solve, and having a highly efficient and parallel framework to solve them is necessary. In this work, a brief review on phase field models is given, followed by a short analysis of the Phase Field Crystal Model solved with Isogeometric Analysis us- ing PetIGA. We end with an introduction to a new modeling concept, where free energy functions are built with a periodic equilibrium structure in mind.

  4. Development of the neutron reference calibration field using a {sup 252}Cf standard source surrounded with PMMA moderators

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, T.; Kanai, K.; Tsujimura, N. [Japan Nuclear Cycle Development Institute, Ibaraki-ken (Japan)

    2002-07-01

    The authors developed the neutron reference calibration fields using a {sup 252} Cf standard source surrounded with PMMA moderators at the Japan Nuclear Cycle Development (JNC), Tokai Works. The moderators are co-axial, hollow cylinders made of lead-contained PMMA with a thickness of 13.5, 35.0, 59.5 and 77.0mm, and the {sup 252} Cf source is guided to the geometric center of moderators by the pneumatic system. These fields can provide the moderated neutron spectra very similar to those encountered around the globe-boxes of the fabrication process of MOX (PuO{sub 2}-UO{sub 2} mixed oxide) fuel. The neutron energy spectrum at the reference calibration point was evaluated from the calculations by MCNP4B and the measurements by the INS-type Bonner multi-sphere spectrometer and the hydrogen-filled proportional counters. The calculated neutron spectra were in good agreements with the measured ones. These fields were characterized in terms of the neutron fluence rate, spectral composition and ambient dose equivalent rate, and have served for the response-characterization of various neutron survey instruments.

  5. Evaluation of recent quantitative magnetospheric magnetic field models

    International Nuclear Information System (INIS)

    Walker, R.J.

    1976-01-01

    Recent quantitative magnetospheric field models contain many features not found in earlier models. Magnetopause models which include the effects of the dipole tilt were presented. More realistic models of the tail field include tail currents which close on the magnetopause, cross-tail currents of finite thickness, and cross-tail current models which model the position of the neutral sheet as a function of tilt. Finally, models have attempted to calculate the field of currents distributed in the inner magnetosphere. As the purpose of a magnetospheric model is to provide a mathematical description of the field that reasonably reproduces the observed magnetospheric field, several recent models were compared with the observed ΔB(B/sub observed/--B/sub main field/) contours. Models containing only contributions from magnetopause and tail current systems are able to reproduce the observed quiet time field only in an extremely qualitative way. The best quantitative agreement between models and observations occurs when currents distributed in the inner magnetosphere are added to the magnetopause and tail current systems. However, the distributed current models are valid only for zero tilt. Even the models which reproduce the average observed field reasonably well may not give physically reasonable field gradients. Three of the models evaluated contain regions in the near tail in which the field gradient reverses direction. One region in which all the models fall short is that around the polar cusp, though most can be used to calculate the position of the last closed field line reasonably well

  6. Face it a visual reference for multi-ethnic facial modeling

    CERN Document Server

    Beckmann Wells, Patricia

    2013-01-01

    Face It  presents practical hands-on techniques, 3D modeling and sculpting tools with Maya and ZBrush production pipelines, uniquely focused on the facial modeling of 7 ethnicity models, featuring over 100 different models ranging in age from newborn to elderly characters. Face It is a resource for academic and professionals alike. Explore the modeling possibilities beyond the digital reference galleries online. No more having to adapt medical anatomy texts to your own models! Explore the finite details of facial anatomy with focus on skull development, muscle structure, e

  7. MATHEMATICAL MODEL OF TRIAXIAL MULTIMODE ATTITUDE AND HEADING REFERENCE SYSTEM

    Directory of Open Access Journals (Sweden)

    Olha Sushchenko

    2017-07-01

    Full Text Available Purpose: The paper deals with the mathematical description of the gimballed attitude and heading reference systems, which can be applied in design of strategic precision navigation systems. The main goal is to created mathematical description taking into consideration the necessity to use different navigations operating modes of this class of navigation systems. To provide the high accuracy the indirect control is used when the position of the gimballed platform is controlled by signals of gyroscopic devices, which are corrected using accelerometer’s signals. Methods: To solve the given problem the methods of the classical theoretical mechanics, gyro theory, and inertial navigation are used. Results: The full mathematical model of the gimballed attitude and heading reference system is derived including descriptions of different operating modes. The mathematical models of the system Expressions for control and correction moments in the different modes are represented. The simulation results are given. Conclusions: The represented results prove efficiency of the proposed models. Developed mathematical models can be useful for design of navigation systems of the wide class of moving vehicles.

  8. Current densities in a pregnant woman model induced by simultaneous ELF electric and magnetic field exposure

    International Nuclear Information System (INIS)

    Cech, R; Leitgeb, N; Pediaditis, M

    2008-01-01

    The pregnant woman model SILVY was studied to ascertain to what extent the electric current densities induced by 50 Hz homogeneous electric and magnetic fields increase in the case of simultaneous exposure. By vectorial addition of the electric current densities, it could be shown that under worst case conditions the basic restrictions recommended by ICNIRP (International Commission on Non-Ionizing Radiation Protection) guidelines are exceeded within the central nervous system (CNS) of the mother, whereas in sole field exposure they are not. However, within the foetus the induced current densities do not comply with basic restrictions, either from single reference-level electric fields or from simultaneous exposure to electric and magnetic fields. Basic limits were considerably exceeded

  9. An evaluation of Tsyganenko magnetic field model

    International Nuclear Information System (INIS)

    Fairfield, D.H.

    1991-01-01

    A long-standing goal of magnetospheric physics has been to produce a model of the Earth's magnetic field that can accurately predict the field vector at all locations within the magnetosphere for all dipole tilt angles and for various solar wind or magnetic activity conditions. A number of models make such predictions, but some only for limited spatial regions, some only for zero tilt angle, and some only for arbitrary conditions. No models depend explicitly on solar wind conditions. A data set of more than 22,000 vector averages of the magnetosphere magnetic field over 0.5 R E regions is used to evaluate Tsyganenko's 1982 and 1987 magnetospheric magnetic field models. The magnetic field predicted by the model in various regions is compared to observations to find systematic discrepancies which future models might address. While agreement is generally good, discrepancies are noted which include: (1) a lack of adequate field line stretching in the tail and ring current regions; (2) an inability to predict weak enough fields in the polar cusps; and (3) a deficiency of Kp as a predictor of the field configuration

  10. Reviews and syntheses: Field data to benchmark the carbon cycle models for tropical forests

    Science.gov (United States)

    Clark, Deborah A.; Asao, Shinichi; Fisher, Rosie; Reed, Sasha; Reich, Peter B.; Ryan, Michael G.; Wood, Tana E.; Yang, Xiaojuan

    2017-10-01

    For more accurate projections of both the global carbon (C) cycle and the changing climate, a critical current need is to improve the representation of tropical forests in Earth system models. Tropical forests exchange more C, energy, and water with the atmosphere than any other class of land ecosystems. Further, tropical-forest C cycling is likely responding to the rapid global warming, intensifying water stress, and increasing atmospheric CO2 levels. Projections of the future C balance of the tropics vary widely among global models. A current effort of the modeling community, the ILAMB (International Land Model Benchmarking) project, is to compile robust observations that can be used to improve the accuracy and realism of the land models for all major biomes. Our goal with this paper is to identify field observations of tropical-forest ecosystem C stocks and fluxes, and of their long-term trends and climatic and CO2 sensitivities, that can serve this effort. We propose criteria for reference-level field data from this biome and present a set of documented examples from old-growth lowland tropical forests. We offer these as a starting point towards the goal of a regularly updated consensus set of benchmark field observations of C cycling in tropical forests.

  11. Developing the Next Generation NATO Reference Mobility Model

    Science.gov (United States)

    2016-06-27

    data through cooperative development with test organizations standards committees. 27 June 2016 UNCLASSIFIED: Distribution Statement A. Approved for...Approved for public release; distribution is unlimited.(#27992) Vehicle Performance Modeling in Soft Soil 27 June 2016 Field test calibrated height field...road, urban rubble, soil, snow/ice Urban (all) Powertrain Performance Grading, turning, fuel economy Cooling Amphibious Operations Fording, swimming

  12. Systematic approach for the identification of process reference models

    CSIR Research Space (South Africa)

    Van Der Merwe, A

    2009-02-01

    Full Text Available and make it economically viable. In the identification of core elements within the process reference model, the focus is often on the end-product and not on the procedure used to identify the elements. As often proved in development of projects, there is a...

  13. Characterization of CERN-EU high energy reference radiation fields with recombination chamber

    International Nuclear Information System (INIS)

    Golnik, N.

    1998-01-01

    The CERN-EU reference radiation field facility (called CERFF) is available behind a shielding of high-energy particles beam at CERN since 1993. At present the parameters of the radiation from beam target are well investigated, however, there are still some serious doubts concerning contribution of low-LET concurrent radiation. This paper presents an experimental procedure for determination of the contribution from the concurrent radiation by measuring the absorbed dose and recombination index of radiation quality at different beam intensities. Additionally, the values of H * (10) were measured in several measuring locations. Measurements were performed with a REM-2 recombination chamber and compared with those obtained by using a HANDI-TEPC instrument. (author)

  14. Electric Field Encephalography as a tool for functional brain research: a modeling study.

    Directory of Open Access Journals (Sweden)

    Yury Petrov

    Full Text Available We introduce the notion of Electric Field Encephalography (EFEG based on measuring electric fields of the brain and demonstrate, using computer modeling, that given the appropriate electric field sensors this technique may have significant advantages over the current EEG technique. Unlike EEG, EFEG can be used to measure brain activity in a contactless and reference-free manner at significant distances from the head surface. Principal component analysis using simulated cortical sources demonstrated that electric field sensors positioned 3 cm away from the scalp and characterized by the same signal-to-noise ratio as EEG sensors provided the same number of uncorrelated signals as scalp EEG. When positioned on the scalp, EFEG sensors provided 2-3 times more uncorrelated signals. This significant increase in the number of uncorrelated signals can be used for more accurate assessment of brain states for non-invasive brain-computer interfaces and neurofeedback applications. It also may lead to major improvements in source localization precision. Source localization simulations for the spherical and Boundary Element Method (BEM head models demonstrated that the localization errors are reduced two-fold when using electric fields instead of electric potentials. We have identified several techniques that could be adapted for the measurement of the electric field vector required for EFEG and anticipate that this study will stimulate new experimental approaches to utilize this new tool for functional brain research.

  15. An innovative service process development based on a reference model

    Directory of Open Access Journals (Sweden)

    Lorenzo Sanfelice Frazzon

    2015-06-01

    Full Text Available This article examines the new service development (NSD process, focusing specifically in a case of a financial service, guided by the following research questions: what are the processes and practices used in the development and design of new financial services? How the results of the financial NSD proposal reflects on the NSD are as a whole? Therefore, the study aims to show and describe a financial service development, conducted at Helpinveste. The paper focuses on the Conceptual Design service (activities: definition of specifications and development of alternative solutions for the service and Service Process Design (Service Representation phases. The methodological procedures are based on the process approach, using a reference model for developing new services. In order to operationalize the model, several techniques for the various stages of the project were used, e.g. QFD and Service Blueprint. Lastly, conclusions report contributions from the reference model application, both theoretical and practical contributions, as well the limitations and further research recommendations.

  16. Updated Reference Model for Heat Generation in the Lithosphere

    Science.gov (United States)

    Wipperfurth, S. A.; Sramek, O.; Roskovec, B.; Mantovani, F.; McDonough, W. F.

    2017-12-01

    Models integrating geophysics and geochemistry allow for characterization of the Earth's heat budget and geochemical evolution. Global lithospheric geophysical models are now constrained by surface and body wave data and are classified into several unique tectonic types. Global lithospheric geochemical models have evolved from petrological characterization of layers to a combination of petrologic and seismic constraints. Because of these advances regarding our knowledge of the lithosphere, it is necessary to create an updated chemical and physical reference model. We are developing a global lithospheric reference model based on LITHO1.0 (segmented into 1°lon x 1°lat x 9-layers) and seismological-geochemical relationships. Uncertainty assignments and correlations are assessed for its physical attributes, including layer thickness, Vp and Vs, and density. This approach yields uncertainties for the masses of the crust and lithospheric mantle. Heat producing element abundances (HPE: U, Th, and K) are ascribed to each volume element. These chemical attributes are based upon the composition of subducting sediment (sediment layers), composition of surface rocks (upper crust), a combination of petrologic and seismic correlations (middle and lower crust), and a compilation of xenolith data (lithospheric mantle). The HPE abundances are correlated within each voxel, but not vertically between layers. Efforts to provide correlation of abundances horizontally between each voxel are discussed. These models are used further to critically evaluate the bulk lithosphere heat production in the continents and the oceans. Cross-checks between our model and results from: 1) heat flux (Artemieva, 2006; Davies, 2013; Cammarano and Guerri, 2017), 2) gravity (Reguzzoni and Sampietro, 2015), and 3) geochemical and petrological models (Rudnick and Gao, 2014; Hacker et al. 2015) are performed.

  17. Conformal FDTD modeling wake fields

    Energy Technology Data Exchange (ETDEWEB)

    Jurgens, T.; Harfoush, F.

    1991-05-01

    Many computer codes have been written to model wake fields. Here we describe the use of the Conformal Finite Difference Time Domain (CFDTD) method to model the wake fields generated by a rigid beam traveling through various accelerating structures. The non- cylindrical symmetry of some of the problems considered here requires the use of a three dimensional code. In traditional FDTD codes, curved surfaces are approximated by rectangular steps. The errors introduced in wake field calculations by such an approximation can be reduced by increasing the mesh size, therefore increasing the cost of computing. Another approach, validated here, deforms Ampere and Faraday contours near a media interface so as to conform to the interface. These improvements of the FDTD method result in better accuracy of the fields at asymptotically no computational cost. This method is also capable of modeling thin wires as found in beam profile monitors, and slots and cracks as found in resistive wall motions. 4 refs., 5 figs.

  18. Preliminary Phase Field Computational Model Development

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yulan [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hu, Shenyang Y. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Xu, Ke [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Suter, Jonathan D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); McCloy, John S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Johnson, Bradley R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Ramuhalli, Pradeep [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-12-15

    This interim report presents progress towards the development of meso-scale models of magnetic behavior that incorporate microstructural information. Modeling magnetic signatures in irradiated materials with complex microstructures (such as structural steels) is a significant challenge. The complexity is addressed incrementally, using the monocrystalline Fe (i.e., ferrite) film as model systems to develop and validate initial models, followed by polycrystalline Fe films, and by more complicated and representative alloys. In addition, the modeling incrementally addresses inclusion of other major phases (e.g., martensite, austenite), minor magnetic phases (e.g., carbides, FeCr precipitates), and minor nonmagnetic phases (e.g., Cu precipitates, voids). The focus of the magnetic modeling is on phase-field models. The models are based on the numerical solution to the Landau-Lifshitz-Gilbert equation. From the computational standpoint, phase-field modeling allows the simulation of large enough systems that relevant defect structures and their effects on functional properties like magnetism can be simulated. To date, two phase-field models have been generated in support of this work. First, a bulk iron model with periodic boundary conditions was generated as a proof-of-concept to investigate major loop effects of single versus polycrystalline bulk iron and effects of single non-magnetic defects. More recently, to support the experimental program herein using iron thin films, a new model was generated that uses finite boundary conditions representing surfaces and edges. This model has provided key insights into the domain structures observed in magnetic force microscopy (MFM) measurements. Simulation results for single crystal thin-film iron indicate the feasibility of the model for determining magnetic domain wall thickness and mobility in an externally applied field. Because the phase-field model dimensions are limited relative to the size of most specimens used in

  19. A reference-dependent model of the price-quality heuristic

    NARCIS (Netherlands)

    Gneezy, A.; Gneezy, U.; Lauga, D.O.

    2014-01-01

    People often use price as a proxy for quality, resulting in a positive correlation between prices and product liking, known as the "price- quality" (P-Q) heuristic. Using data from three experiments conducted at a winery, this article offers a more complex and complete reference-dependent model of

  20. DQ reference frame modeling and control of single-phase active power decoupling circuits

    DEFF Research Database (Denmark)

    Tang, Yi; Qin, Zian; Blaabjerg, Frede

    2015-01-01

    . This paper presents the dq synchronous reference frame modeling of single-phase power decoupling circuits and a complete model describing the dynamics of dc-link ripple voltage is presented. The proposed model is universal and valid for both inductive and capacitive decoupling circuits, and the input...... of decoupling circuits can be either dependent or independent of its front-end converters. Based on this model, a dq synchronous reference frame controller is designed which allows the decoupling circuit to operate in two different modes because of the circuit symmetry. Simulation and experimental results...... are presented to verify the effectiveness of the proposed modeling and control method....

  1. Geant4 simulation of the CERN-EU high-energy reference field (CERF) facility.

    Science.gov (United States)

    Prokopovich, D A; Reinhard, M I; Cornelius, I M; Rosenfeld, A B

    2010-09-01

    The CERN-EU high-energy reference field facility is used for testing and calibrating both active and passive radiation dosemeters for radiation protection applications in space and aviation. Through a combination of a primary particle beam, target and a suitable designed shielding configuration, the facility is able to reproduce the neutron component of the high altitude radiation field relevant to the jet aviation industry. Simulations of the facility using the GEANT4 (GEometry ANd Tracking) toolkit provide an improved understanding of the neutron particle fluence as well as the particle fluence of other radiation components present. The secondary particle fluence as a function of the primary particle fluence incident on the target and the associated dose equivalent rates were determined at the 20 designated irradiation positions available at the facility. Comparisons of the simulated results with previously published simulations obtained using the FLUKA Monte Carlo code, as well as with experimental results of the neutron fluence obtained with a Bonner sphere spectrometer, are made.

  2. Rapid core field variations during the satellite era: Investigations using stochastic process based field models

    DEFF Research Database (Denmark)

    Finlay, Chris; Olsen, Nils; Gillet, Nicolas

    We present a new ensemble of time-dependent magnetic field models constructed from satellite and observatory data spanning 1997-2013 that are compatible with prior information concerning the temporal spectrum of core field variations. These models allow sharper field changes compared to tradition...... physical hypotheses can be tested by asking questions of the entire ensemble of core field models, rather than by interpreting any single model.......We present a new ensemble of time-dependent magnetic field models constructed from satellite and observatory data spanning 1997-2013 that are compatible with prior information concerning the temporal spectrum of core field variations. These models allow sharper field changes compared to traditional...... regularization methods based on minimizing the square of second or third time derivative. We invert satellite and observatory data directly by adopting the external field and crustal field modelling framework of the CHAOS model, but apply the stochastic process method of Gillet et al. (2013) to the core field...

  3. Model reference adaptive control of flexible robots in the presence of sudden load changes

    Science.gov (United States)

    Steinvorth, Rodrigo; Kaufman, Howard; Neat, Gregory

    1991-01-01

    Direct command generator tracker based model reference adaptive control (MRAC) algorithms are applied to the dynamics for a flexible-joint arm in the presence of sudden load changes. Because of the need to satisfy a positive real condition, such MRAC procedures are designed so that a feedforward augmented output follows the reference model output, thus, resulting in an ultimately bounded rather than zero output error. Thus, modifications are suggested and tested that: (1) incorporate feedforward into the reference model's output as well as the plant's output, and (2) incorporate a derivative term into only the process feedforward loop. The results of these simulations give a response with zero steady state model following error, and thus encourage further use of MRAC for more complex flexibile robotic systems.

  4. Reference models for forming organisational or collaborative pedagogical best practices

    NARCIS (Netherlands)

    Lee, Chien-Sing; Koper, Rob; Kommers, Piet; Hedberg, John

    2008-01-01

    Lee, Chien-Sing, Koper, R., Kommers, P., & Hedberg, John (Eds.) (2008). Reference models for forming organisational or collaborative pedagogical best practices [special issue]. International Journal of Continuing Engineering Education and Life-Long Learning, 18(1).

  5. Model-reference robust tuning of PID controllers

    CERN Document Server

    Alfaro, Victor M

    2016-01-01

    This book presents a unified methodology for the design of PID controllers that encompasses the wide range of different dynamics to be found in industrial processes. This is extended to provide a coherent way of dealing with the tuning of PID controllers. The particular method at the core of the book is the so-called model-reference robust tuning (MoReRT), developed by the authors. MoReRT constitutes a novel and powerful way of thinking of a robust design and taking into account the usual design trade-offs encountered in any control design problem. The book starts by presenting the different two-degree-of-freedom PID control algorithm variations and their conversion relations as well as the indexes used for performance, robustness and fragility evaluation:the bases of the proposed model. Secondly, the MoReRT design methodology and normalized controlled process models and controllers used in the design are described in order to facilitate the formulation of the different design problems and subsequent derivati...

  6. Reference Model 2: "Rev 0" Rotor Design

    Energy Technology Data Exchange (ETDEWEB)

    Barone, Matthew F. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Berg, Jonathan Charles [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Griffith, Daniel [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2011-12-01

    The preliminary design for a three-bladed cross-flow rotor for a reference marine hydrokinetic turbine is presented. A rotor performance design code is described, along with modifications to the code to allow prediction of blade support strut drag as well as interference between two counter-rotating rotors. The rotor is designed to operate in a reference site corresponding to a riverine environment. Basic rotor performance and rigid-body loads calculations are performed to size the rotor elements and select the operating speed range. The preliminary design is verified with a simple finite element model that provides estimates of bending stresses during operation. A concept for joining the blades and support struts is developed and analyzed with a separate finite element analysis. Rotor mass, production costs, and annual energy capture are estimated in order to allow calculations of system cost-of-energy. Evaluation Only. Created with Aspose.Pdf.Kit. Copyright 2002-2011 Aspose Pty Ltd Evaluation Only. Created with Aspose.Pdf.Kit. Copyright 2002-2011 Aspose Pty Ltd

  7. Tunneling field effect transistor technology

    CERN Document Server

    Chan, Mansun

    2016-01-01

    This book provides a single-source reference to the state-of-the art in tunneling field effect transistors (TFETs). Readers will learn the TFETs physics from advanced atomistic simulations, the TFETs fabrication process and the important roles that TFETs will play in enabling integrated circuit designs for power efficiency. · Provides comprehensive reference to tunneling field effect transistors (TFETs); · Covers all aspects of TFETs, from device process to modeling and applications; · Enables design of power-efficient integrated circuits, with low power consumption TFETs.

  8. Neutron Reference Benchmark Field Specifications: ACRR Polyethylene-Lead-Graphite (PLG) Bucket Environment (ACRR-PLG-CC-32-CL).

    Energy Technology Data Exchange (ETDEWEB)

    Vega, Richard Manuel [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Parm, Edward J. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Griffin, Patrick J. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Vehar, David W. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    2015-07-01

    This report was put together to support the International Atomic Energy Agency (IAEA) REAL- 2016 activity to validate the dosimetry community’s ability to use a consistent set of activation data and to derive consistent spectral characterizations. The report captures details of integral measurements taken in the Annular Core Research Reactor (ACRR) central cavity with the Polyethylene-Lead-Graphite (PLG) bucket, reference neutron benchmark field. The field is described and an “a priori” calculated neutron spectrum is reported, based on MCNP6 calculations, and a subject matter expert (SME) based covariance matrix is given for this “a priori” spectrum. The results of 37 integral dosimetry measurements in the neutron field are reported.

  9. Biomass Scenario Model Documentation: Data and References

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Y.; Newes, E.; Bush, B.; Peterson, S.; Stright, D.

    2013-05-01

    The Biomass Scenario Model (BSM) is a system dynamics model that represents the entire biomass-to-biofuels supply chain, from feedstock to fuel use. The BSM is a complex model that has been used for extensive analyses; the model and its results can be better understood if input data used for initialization and calibration are well-characterized. It has been carefully validated and calibrated against the available data, with data gaps filled in using expert opinion and internally consistent assumed values. Most of the main data sources that feed into the model are recognized as baseline values by the industry. This report documents data sources and references in Version 2 of the BSM (BSM2), which only contains the ethanol pathway, although subsequent versions of the BSM contain multiple conversion pathways. The BSM2 contains over 12,000 total input values, with 506 distinct variables. Many of the variables are opportunities for the user to define scenarios, while others are simply used to initialize a stock, such as the initial number of biorefineries. However, around 35% of the distinct variables are defined by external sources, such as models or reports. The focus of this report is to provide insight into which sources are most influential in each area of the supply chain.

  10. Reference models and incentive regulation of electricity distribution networks: An evaluation of Sweden's Network Performance Assessment Model (NPAM)

    International Nuclear Information System (INIS)

    Jamasb, Tooraj; Pollitt, Michael

    2008-01-01

    Electricity sector reforms across the world have led to a search for innovative approaches to regulation that promote efficiency in the natural monopoly distribution networks and reduce their service charges. To this aim, a number of countries have adopted incentive regulation models based on efficiency benchmarking. While most regulators have used parametric and non-parametric frontier-based methods of benchmarking some have adopted engineering-designed 'reference firm' or 'norm' models. This paper examines the incentive properties and related aspects of the reference firm model-NPAM-as used in Sweden and compares this with frontier-based benchmarking methods. We identify a number of important differences between the two approaches that are not readily apparent and discuss their ramifications for the regulatory objectives and process. We conclude that, on balance, the reference models are less appropriate as benchmarks than real firms. Also, the implementation framework based on annual ex-post reviews exacerbates the regulatory problems mainly by increasing uncertainty and reducing the incentive for innovation

  11. Gravity field recovery in the framework of a Geodesy and Time Reference in Space (GETRIS)

    Science.gov (United States)

    Hauk, Markus; Schlicht, Anja; Pail, Roland; Murböck, Michael

    2017-04-01

    The study ;Geodesy and Time Reference in Space; (GETRIS), funded by European Space Agency (ESA), evaluates the potential and opportunities coming along with a global space-borne infrastructure for data transfer, clock synchronization and ranging. Gravity field recovery could be one of the first beneficiary applications of such an infrastructure. This paper analyzes and evaluates the two-way high-low satellite-to-satellite-tracking as a novel method and as a long-term perspective for the determination of the Earth's gravitational field, using it as a synergy of one-way high-low combined with low-low satellite-to-satellite-tracking, in order to generate adequate de-aliasing products. First planned as a constellation of geostationary satellites, it turned out, that an integration of European Union Global Navigation Satellite System (Galileo) satellites (equipped with inter-Galileo links) into a Geostationary Earth Orbit (GEO) constellation would extend the capability of such a mission constellation remarkably. We report about simulations of different Galileo and Low Earth Orbiter (LEO) satellite constellations, computed using time variable geophysical background models, to determine temporal changes in the Earth's gravitational field. Our work aims at an error analysis of this new satellite/instrument scenario by investigating the impact of different error sources. Compared to a low-low satellite-to-satellite-tracking mission, results show reduced temporal aliasing errors due to a more isotropic error behavior caused by an improved observation geometry, predominantly in near-radial direction within the inter-satellite-links, as well as the potential of an improved gravity recovery with higher spatial and temporal resolution. The major error contributors of temporal gravity retrieval are aliasing errors due to undersampling of high frequency signals (mainly atmosphere, ocean and ocean tides). In this context, we investigate adequate methods to reduce these errors. We

  12. Numerical approach of multi-field two-phase flow models in the OVAP code

    International Nuclear Information System (INIS)

    Anela Kumbaro

    2005-01-01

    use full Eigen-structure information. Basic comparisons in terms of numerical results and physical modeling will be provided and interpreted. The intent is to provide guidelines for future development of such methods and models. References: [1] Lahey, R.T. Jr., Drew D.A. An Analysis of Two-Phase Flow and Heat Transfer using a Multidimensional, Multi-Field, Two-Fluid Computational Fluid Dynamics (CFD) Model, Japan/US Seminar on Two-Phase Flow Dynamics, California, June 5-8, 2000. [2] Lo S., Some recent developments and applications of CFD to multiphase flows in stirred reactors, AMIF-ESF Workshop, Computing two-phase flows, Aussois, 2000. [3] Roe P.L., Approximate Riemann solvers, parameter vectors, and difference schemes, J. Comp. Phys., 43(2), 1981. [4] Toumi and A. Kumbaro, An Approximate Linearized Riemann Solver for a Two-Fluid Model, J. Comput. Phys., 124, 286-300, 1996. [5] A. Kumbaro, I. Toumi and V. Seignole, Numerical Modeling of Two-Phase Flows Using Advanced Two Fluid Systems, Tenth International Conference on Nuclear Engineering, April 14-18 2002, Arlington, Virginia, USA. (author)

  13. Mean Field Games Models-A Brief Survey

    KAUST Repository

    Gomes, Diogo A.

    2013-11-20

    The mean-field framework was developed to study systems with an infinite number of rational agents in competition, which arise naturally in many applications. The systematic study of these problems was started, in the mathematical community by Lasry and Lions, and independently around the same time in the engineering community by P. Caines, Minyi Huang, and Roland Malhamé. Since these seminal contributions, the research in mean-field games has grown exponentially, and in this paper we present a brief survey of mean-field models as well as recent results and techniques. In the first part of this paper, we study reduced mean-field games, that is, mean-field games, which are written as a system of a Hamilton-Jacobi equation and a transport or Fokker-Planck equation. We start by the derivation of the models and by describing some of the existence results available in the literature. Then we discuss the uniqueness of a solution and propose a definition of relaxed solution for mean-field games that allows to establish uniqueness under minimal regularity hypothesis. A special class of mean-field games that we discuss in some detail is equivalent to the Euler-Lagrange equation of suitable functionals. We present in detail various additional examples, including extensions to population dynamics models. This section ends with a brief overview of the random variables point of view as well as some applications to extended mean-field games models. These extended models arise in problems where the costs incurred by the agents depend not only on the distribution of the other agents, but also on their actions. The second part of the paper concerns mean-field games in master form. These mean-field games can be modeled as a partial differential equation in an infinite dimensional space. We discuss both deterministic models as well as problems where the agents are correlated. We end the paper with a mean-field model for price impact. © 2013 Springer Science+Business Media New York.

  14. Mean Field Games Models-A Brief Survey

    KAUST Repository

    Gomes, Diogo A.; Saú de, Joã o

    2013-01-01

    The mean-field framework was developed to study systems with an infinite number of rational agents in competition, which arise naturally in many applications. The systematic study of these problems was started, in the mathematical community by Lasry and Lions, and independently around the same time in the engineering community by P. Caines, Minyi Huang, and Roland Malhamé. Since these seminal contributions, the research in mean-field games has grown exponentially, and in this paper we present a brief survey of mean-field models as well as recent results and techniques. In the first part of this paper, we study reduced mean-field games, that is, mean-field games, which are written as a system of a Hamilton-Jacobi equation and a transport or Fokker-Planck equation. We start by the derivation of the models and by describing some of the existence results available in the literature. Then we discuss the uniqueness of a solution and propose a definition of relaxed solution for mean-field games that allows to establish uniqueness under minimal regularity hypothesis. A special class of mean-field games that we discuss in some detail is equivalent to the Euler-Lagrange equation of suitable functionals. We present in detail various additional examples, including extensions to population dynamics models. This section ends with a brief overview of the random variables point of view as well as some applications to extended mean-field games models. These extended models arise in problems where the costs incurred by the agents depend not only on the distribution of the other agents, but also on their actions. The second part of the paper concerns mean-field games in master form. These mean-field games can be modeled as a partial differential equation in an infinite dimensional space. We discuss both deterministic models as well as problems where the agents are correlated. We end the paper with a mean-field model for price impact. © 2013 Springer Science+Business Media New York.

  15. Order-Constrained Reference Priors with Implications for Bayesian Isotonic Regression, Analysis of Covariance and Spatial Models

    Science.gov (United States)

    Gong, Maozhen

    Selecting an appropriate prior distribution is a fundamental issue in Bayesian Statistics. In this dissertation, under the framework provided by Berger and Bernardo, I derive the reference priors for several models which include: Analysis of Variance (ANOVA)/Analysis of Covariance (ANCOVA) models with a categorical variable under common ordering constraints, the conditionally autoregressive (CAR) models and the simultaneous autoregressive (SAR) models with a spatial autoregression parameter rho considered. The performances of reference priors for ANOVA/ANCOVA models are evaluated by simulation studies with comparisons to Jeffreys' prior and Least Squares Estimation (LSE). The priors are then illustrated in a Bayesian model of the "Risk of Type 2 Diabetes in New Mexico" data, where the relationship between the type 2 diabetes risk (through Hemoglobin A1c) and different smoking levels is investigated. In both simulation studies and real data set modeling, the reference priors that incorporate internal order information show good performances and can be used as default priors. The reference priors for the CAR and SAR models are also illustrated in the "1999 SAT State Average Verbal Scores" data with a comparison to a Uniform prior distribution. Due to the complexity of the reference priors for both CAR and SAR models, only a portion (12 states in the Midwest) of the original data set is considered. The reference priors can give a different marginal posterior distribution compared to a Uniform prior, which provides an alternative for prior specifications for areal data in Spatial statistics.

  16. Anisotropy in wavelet-based phase field models

    KAUST Repository

    Korzec, Maciek; Mü nch, Andreas; Sü li, Endre; Wagner, Barbara

    2016-01-01

    When describing the anisotropic evolution of microstructures in solids using phase-field models, the anisotropy of the crystalline phases is usually introduced into the interfacial energy by directional dependencies of the gradient energy coefficients. We consider an alternative approach based on a wavelet analogue of the Laplace operator that is intrinsically anisotropic and linear. The paper focuses on the classical coupled temperature/Ginzburg--Landau type phase-field model for dendritic growth. For the model based on the wavelet analogue, existence, uniqueness and continuous dependence on initial data are proved for weak solutions. Numerical studies of the wavelet based phase-field model show dendritic growth similar to the results obtained for classical phase-field models.

  17. Anisotropy in wavelet-based phase field models

    KAUST Repository

    Korzec, Maciek

    2016-04-01

    When describing the anisotropic evolution of microstructures in solids using phase-field models, the anisotropy of the crystalline phases is usually introduced into the interfacial energy by directional dependencies of the gradient energy coefficients. We consider an alternative approach based on a wavelet analogue of the Laplace operator that is intrinsically anisotropic and linear. The paper focuses on the classical coupled temperature/Ginzburg--Landau type phase-field model for dendritic growth. For the model based on the wavelet analogue, existence, uniqueness and continuous dependence on initial data are proved for weak solutions. Numerical studies of the wavelet based phase-field model show dendritic growth similar to the results obtained for classical phase-field models.

  18. Stress field modelling from digital geological map data

    Science.gov (United States)

    Albert, Gáspár; Barancsuk, Ádám; Szentpéteri, Krisztián

    2016-04-01

    calculated from the fracture criterion. The calculation includes the gravitational acceleration, the average density of rocks and the experimental 60 degree of the fracture angle from the normal of the fault plane. This way, the stress tensors are calculated as absolute pressure values per square meters on both sides of the faults. If the stress from the overburden is greater than 1 bar (i.e. the faults are buried), a confined compression would be present. Modelling this state of stress may result a confusing pattern of vectors, because in a confined position the horizontal stress vectors may point towards structures primarily associated with extension. To step over this, and to highlight the variability in the stress-field, the model calculates the vectors directly from the differential stress (practically subtracting the minimum principal stress from the critical stress). The result of the modelling is a vector map, which theoretically represents the minimum tectonic pressure in the moment, when the rock body breaks from an initial state. This map - together with the original fault-map - is suitable for determining those areas where unrevealed tectonic, sedimentary and lithological structures are possibly present (e.g. faults, sub-basins and intrusions). With modelling different deformational phases on the same area, change of the stress vectors can be detected which reveals not only the varying directions of the principal stresses, but the tectonic-driven sedimentation patterns too. The decrease of necessary critical stress in the case of a possible reactivation of a fault in subsequent deformation phase can be managed with the down-ranking of the concerning structural elements. Reference: Albert G., Ungvári ZS., Szentpéteri K. 2014: Modeling the present day stress field of the Pannonian Basin from neotectonic maps - In: Beqiraj A, Ionescu C, Christofides G, Uta A, Beqiraj Goga E, Marku S (eds.) Proceedings XX Congress of the Carpathian-Balkan Geological Association

  19. Use of along-track magnetic field differences in lithospheric field modelling

    DEFF Research Database (Denmark)

    Kotsiaros, Stavros; Finlay, Chris; Olsen, Nils

    2015-01-01

    . Experiments in modelling the Earth's lithospheric magnetic field with along-track differences are presented here as a proof of concept. We anticipate that use of such along-track differences in combination with east–west field differences, as are now provided by the Swarm satellite constellation......We demonstrate that first differences of polar orbiting satellite magnetic data in the along-track direction can be used to obtain high resolution models of the lithospheric field. Along-track differences approximate the north–south magnetic field gradients for non-polar latitudes. In a test case......, using 2 yr of low altitude data from the CHAMP satellite, we show that use of along-track differences of vector field data results in an enhanced recovery of the small scale lithospheric field, compared to the use of the vector field data themselves. We show that the along-track technique performs...

  20. Modeling aeolian dune and dune field evolution

    Science.gov (United States)

    Diniega, Serina

    Aeolian sand dune morphologies and sizes are strongly connected to the environmental context and physical processes active since dune formation. As such, the patterns and measurable features found within dunes and dune fields can be interpreted as records of environmental conditions. Using mathematical models of dune and dune field evolution, it should be possible to quantitatively predict dune field dynamics from current conditions or to determine past field conditions based on present-day observations. In this dissertation, we focus on the construction and quantitative analysis of a continuum dune evolution model. We then apply this model towards interpretation of the formative history of terrestrial and martian dunes and dune fields. Our first aim is to identify the controls for the characteristic lengthscales seen in patterned dune fields. Variations in sand flux, binary dune interactions, and topography are evaluated with respect to evolution of individual dunes. Through the use of both quantitative and qualitative multiscale models, these results are then extended to determine the role such processes may play in (de)stabilization of the dune field. We find that sand flux variations and topography generally destabilize dune fields, while dune collisions can yield more similarly-sized dunes. We construct and apply a phenomenological macroscale dune evolution model to then quantitatively demonstrate how dune collisions cause a dune field to evolve into a set of uniformly-sized dunes. Our second goal is to investigate the influence of reversing winds and polar processes in relation to dune slope and morphology. Using numerical experiments, we investigate possible causes of distinctive morphologies seen in Antarctic and martian polar dunes. Finally, we discuss possible model extensions and needed observations that will enable the inclusion of more realistic physical environments in the dune and dune field evolution models. By elucidating the qualitative and

  1. Model Reference Adaptive Control of the Air Flow Rate of Centrifugal Compressor Using State Space Method

    International Nuclear Information System (INIS)

    Han, Jaeyoung; Jung, Mooncheong; Yu, Sangseok; Yi, Sun

    2016-01-01

    In this study, a model reference adaptive controller is developed to regulate the outlet air flow rate of centrifugal compressor for automotive supercharger. The centrifugal compressor is developed using the analytical based method to predict the transient behavior of operating and the designed model is validated with experimental data to confirm the system accuracy. The model reference adaptive control structure consists of a compressor model and a MRAC(model reference adaptive control) mechanism. The feedback control do not robust with variation of system parameter but the applied adaptive control is robust even if the system parameter is changed. As a result, the MRAC was regulated to reference air flow rate. Also MRAC was found to be more robust control compared with the feedback control even if the system parameter is changed.

  2. Model Reference Adaptive Control of the Air Flow Rate of Centrifugal Compressor Using State Space Method

    Energy Technology Data Exchange (ETDEWEB)

    Han, Jaeyoung; Jung, Mooncheong; Yu, Sangseok [Chungnam Nat’l Univ., Daejeon (Korea, Republic of); Yi, Sun [North Carolina A and T State Univ., Raleigh (United States)

    2016-08-15

    In this study, a model reference adaptive controller is developed to regulate the outlet air flow rate of centrifugal compressor for automotive supercharger. The centrifugal compressor is developed using the analytical based method to predict the transient behavior of operating and the designed model is validated with experimental data to confirm the system accuracy. The model reference adaptive control structure consists of a compressor model and a MRAC(model reference adaptive control) mechanism. The feedback control do not robust with variation of system parameter but the applied adaptive control is robust even if the system parameter is changed. As a result, the MRAC was regulated to reference air flow rate. Also MRAC was found to be more robust control compared with the feedback control even if the system parameter is changed.

  3. A Hamiltonian five-field gyrofluid model

    Energy Technology Data Exchange (ETDEWEB)

    Keramidas Charidakos, I.; Waelbroeck, F. L.; Morrison, P. J. [Institute for Fusion Studies and Department of Physics, The University of Texas at Austin, Austin, TX 78712 (United States)

    2015-11-15

    A Lie-Poisson bracket is presented for a five-field gyrofluid model, thereby showing the model to be Hamiltonian. The model includes the effects of magnetic field curvature and describes the evolution of the electron and ion gyro-center densities, the parallel component of the ion and electron velocities, and the ion temperature. The quasineutrality property and Ampère's law determine, respectively, the electrostatic potential and magnetic flux. The Casimir invariants are presented, and shown to be associated with five Lagrangian invariants advected by distinct velocity fields. A linear, local study of the model is conducted both with and without Landau and diamagnetic resonant damping terms. Stability criteria and dispersion relations for the electrostatic and the electromagnetic cases are derived and compared with their analogs for fluid and kinetic models.

  4. Phase Field Modeling Using PetIGA

    KAUST Repository

    Vignal, Philippe; Collier, Nathan; Calo, Victor M.

    2013-01-01

    , and having a highly efficient and parallel framework to solve them is necessary. In this work, a brief review on phase field models is given, followed by a short analysis of the Phase Field Crystal Model solved with Isogeometric Analysis us- ing PetIGA. We

  5. An Optimal Control Modification to Model-Reference Adaptive Control for Fast Adaptation

    Science.gov (United States)

    Nguyen, Nhan T.; Krishnakumar, Kalmanje; Boskovic, Jovan

    2008-01-01

    This paper presents a method that can achieve fast adaptation for a class of model-reference adaptive control. It is well-known that standard model-reference adaptive control exhibits high-gain control behaviors when a large adaptive gain is used to achieve fast adaptation in order to reduce tracking error rapidly. High gain control creates high-frequency oscillations that can excite unmodeled dynamics and can lead to instability. The fast adaptation approach is based on the minimization of the squares of the tracking error, which is formulated as an optimal control problem. The necessary condition of optimality is used to derive an adaptive law using the gradient method. This adaptive law is shown to result in uniform boundedness of the tracking error by means of the Lyapunov s direct method. Furthermore, this adaptive law allows a large adaptive gain to be used without causing undesired high-gain control effects. The method is shown to be more robust than standard model-reference adaptive control. Simulations demonstrate the effectiveness of the proposed method.

  6. Reference man models based on normal data from human populations

    International Nuclear Information System (INIS)

    Tanaka, Gi-ichiro; Kawamura, Hisao

    2000-01-01

    Quantitative description of the physical, and metabolic parameters of the human body is the very basic for internal dosimetry. Compilation of anatomical and other types of data Asian populations for internal (and external) dosimetry is of grate significance because of the potential spread of nuclear energy use in the Asian region and the major contribution of the region to the world population (about 58%). It has been observed that some differences exist for habitat, race, body sizes and pattern of food consumption. In the early stage of revision of ICRP Reference man by the Task Group, Characteristics of the human body of non-European populations received considerable attention as well as those of the European populations of different sexes and ages. In this context, an IAEA-RCA Co-ordinated Research Program on Compilation of Anatomical, Physiological and Metabolic Characteristics for a Reference Asian Man endorsed. In later stages of reference Man revision, anatomical data for Asians was discusses together with those of European populations, presumably due to ICRP's decision of unanimous use of the Reference Man for radiation protection. Reference man models for adults and 15, 10, 5, 1, 0 year-old males and females of Asian populations were developed for use in internal and external dosimetry. Based on the concept of ICRP Reference Man (Publication 23), the reference values were derived from the normal organ mass data for Japanese and statistical data on the physique and nutrition of Japanese and Chinese. Also incorporated were variations in physical measurements, as observed in the above mentioned IAEA-RCA Co-ordinated Research Program. The work was partly carried out within the activities of the ICRP Task Group on Reference Man. The weight of the skeleton was adjusted following the revised values in Publication 70. This paper will report basic shared and non-shared characteristics of Reference Man' for Asians and ICRP Reference Man. (author)

  7. Image-optimized Coronal Magnetic Field Models

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Shaela I.; Uritsky, Vadim; Davila, Joseph M., E-mail: shaela.i.jones-mecholsky@nasa.gov, E-mail: shaela.i.jonesmecholsky@nasa.gov [NASA Goddard Space Flight Center, Code 670, Greenbelt, MD 20771 (United States)

    2017-08-01

    We have reported previously on a new method we are developing for using image-based information to improve global coronal magnetic field models. In that work, we presented early tests of the method, which proved its capability to improve global models based on flawed synoptic magnetograms, given excellent constraints on the field in the model volume. In this follow-up paper, we present the results of similar tests given field constraints of a nature that could realistically be obtained from quality white-light coronagraph images of the lower corona. We pay particular attention to difficulties associated with the line-of-sight projection of features outside of the assumed coronagraph image plane and the effect on the outcome of the optimization of errors in the localization of constraints. We find that substantial improvement in the model field can be achieved with these types of constraints, even when magnetic features in the images are located outside of the image plane.

  8. Image-Optimized Coronal Magnetic Field Models

    Science.gov (United States)

    Jones, Shaela I.; Uritsky, Vadim; Davila, Joseph M.

    2017-01-01

    We have reported previously on a new method we are developing for using image-based information to improve global coronal magnetic field models. In that work we presented early tests of the method which proved its capability to improve global models based on flawed synoptic magnetograms, given excellent constraints on the field in the model volume. In this follow-up paper we present the results of similar tests given field constraints of a nature that could realistically be obtained from quality white-light coronagraph images of the lower corona. We pay particular attention to difficulties associated with the line-of-sight projection of features outside of the assumed coronagraph image plane, and the effect on the outcome of the optimization of errors in localization of constraints. We find that substantial improvement in the model field can be achieved with this type of constraints, even when magnetic features in the images are located outside of the image plane.

  9. Direct Model Reference Adaptive Control for a Magnetic Bearing

    Energy Technology Data Exchange (ETDEWEB)

    Durling, Mike [Rensselaer Polytechnic Inst., Troy, NY (United States)

    1999-11-01

    A Direct Model Reference Adaptive Controller (DMRAC) is applied to a magnetic bearing test stand. The bearing of interest is the MBC 500 Magnetic Bearing System manufactured by Magnetic Moments, LLC. The bearing model is presented in state space form and the system transfer function is measured directly using a closed-loop swept sine technique. Next, the bearing models are used to design a phase-lead controller, notch filter and then a DMRAC. The controllers are tuned in simulations and finally are implemented using a combination of MATLAB, SIMULINK and dSPACE. The results show a successful implementation of a DMRAC on the magnetic bearing hardware.

  10. Parabolic Trough Reference Plant for Cost Modeling with the Solar Advisor Model (SAM)

    Energy Technology Data Exchange (ETDEWEB)

    Turchi, C.

    2010-07-01

    This report describes a component-based cost model developed for parabolic trough solar power plants. The cost model was developed by the National Renewable Energy Laboratory (NREL), assisted by WorleyParsons Group Inc., for use with NREL's Solar Advisor Model (SAM). This report includes an overview and explanation of the model, two summary contract reports from WorleyParsons, and an Excel spreadsheet for use with SAM. The cost study uses a reference plant with a 100-MWe capacity and six hours of thermal energy storage. Wet-cooling and dry-cooling configurations are considered. The spreadsheet includes capital and operating cost by component to allow users to estimate the impact of changes in component costs.

  11. Millimeter radiation from a 3D model of the solar atmosphere. II. Chromospheric magnetic field

    Science.gov (United States)

    Loukitcheva, M.; White, S. M.; Solanki, S. K.; Fleishman, G. D.; Carlsson, M.

    2017-05-01

    Aims: We use state-of-the-art, three-dimensional non-local thermodynamic equilibrium (non-LTE) radiative magnetohydrodynamic simulations of the quiet solar atmosphere to carry out detailed tests of chromospheric magnetic field diagnostics from free-free radiation at millimeter and submillimeter wavelengths (mm/submm). Methods: The vertical component of the magnetic field was deduced from the mm/submm brightness spectra and the degree of circular polarization synthesized at millimeter frequencies. We used the frequency bands observed by the Atacama Large Millimeter/Submillimeter Array (ALMA) as a convenient reference. The magnetic field maps obtained describe the longitudinal magnetic field at the effective formation heights of the relevant wavelengths in the solar chromosphere. Results: The comparison of the deduced and model chromospheric magnetic fields at the spatial resolution of both the model and current observations demonstrates a good correlation, but has a tendency to underestimate the model field. The systematic discrepancy of about 10% is probably due to averaging of the restored field over the heights contributing to the radiation, weighted by the strength of the contribution. On the whole, the method of probing the longitudinal component of the magnetic field with free-free emission at mm/submm wavelengths is found to be applicable to measurements of the weak quiet-Sun magnetic fields. However, successful exploitation of this technique requires very accurate measurements of the polarization properties (primary beam and receiver polarization response) of the antennas, which will be the principal factor that determines the level to which chromospheric magnetic fields can be measured. Conclusions: Consequently, high-resolution and high-precision observations of circularly polarized radiation at millimeter wavelengths can be a powerful tool for producing chromospheric longitudinal magnetograms.

  12. Validation of community models: 3. Tracing field lines in heliospheric models

    Science.gov (United States)

    MacNeice, Peter; Elliott, Brian; Acebal, Ariel

    2011-10-01

    Forecasting hazardous gradual solar energetic particle (SEP) bursts at Earth requires accurately modeling field line connections between Earth and the locations of coronal or interplanetary shocks that accelerate the particles. We test the accuracy of field lines reconstructed using four different models of the ambient coronal and inner heliospheric magnetic field, through which these shocks must propagate, including the coupled Wang-Sheeley-Arge (WSA)/ENLIL model. Evaluating the WSA/ENLIL model performance is important since it is the most sophisticated model currently available to space weather forecasters which can model interplanetary coronal mass ejections and, when coupled with particle acceleration and transport models, will provide a complete model for gradual SEP bursts. Previous studies using a simpler Archimedean spiral approach above 2.5 solar radii have reported poor performance. We test the accuracy of the model field lines connecting Earth to the Sun at the onset times of 15 impulsive SEP bursts, comparing the foot points of these field lines with the locations of surface events believed to be responsible for the SEP bursts. We find the WSA/ENLIL model performance is no better than the simplest spiral model, and the principal source of error is the model's inability to reproduce sufficient low-latitude open flux. This may be due to the model's use of static synoptic magnetograms, which fail to account for transient activity in the low corona, during which reconnection events believed to initiate the SEP acceleration may contribute short-lived open flux at low latitudes. Time-dependent coronal models incorporating these transient events may be needed to significantly improve Earth/Sun field line forecasting.

  13. Review of Media Sync Reference Models: Advances and Open Issues

    NARCIS (Netherlands)

    M.A. Montagud Climent (Mario); A.J. Jansen (Jack); P.S. Cesar Garcia (Pablo Santiago); F. Boronat (Fernando); M.A. Montagud Climent (Mario); P.S. Cesar Garcia (Pablo Santiago); F. Boronat (Fernando); H.M. Stokking (Hans)

    2015-01-01

    htmlabstractThe advances on multimedia systems have brought new challenges and requirements for media sync. Over the years, many media sync solutions have been devised. Due to this variety, several studies have surveyed the existing solutions and proposed classification schemes or reference models

  14. The MADE reference information model for interoperable pervasive telemedicine systems

    NARCIS (Netherlands)

    Fung, L.S.N.; Jones, Valerie M.; Hermens, Hermanus J.

    2017-01-01

    Objectives: The main objective is to develop and validate a reference information model (RIM) to support semantic interoperability of pervasive telemedicine systems. The RIM is one component within a larger, computer-interpretable "MADE language" developed by the authors in the context of the

  15. Origin of variation of shift field via annealing at 400°C in a perpendicular-anisotropy magnetic tunnel junction with [Co/Pt]-multilayers based synthetic ferrimagnetic reference layer

    Directory of Open Access Journals (Sweden)

    H. Honjo

    2017-05-01

    Full Text Available We investigated properties of perpendicular-anisotropy magnetic tunnel junctions (p-MTJs with [Co/Pt]-multilayer based synthetic ferrimagnetic reference (SyF layer at elevated annealing temperature Ta from 350°C to 400°C. Shift field HS defined as center field of minor resistance versus magnetic field curve of the MTJs increased with increase of Ta from 350°C to 400°C. The variation of HS is attributed to the variation of saturation magnetic moment in the SyF reference layer. Cross sectional energy dispersive X-ray spectroscopy analysis revealed that Fe element of CoFeB in the reference layer diffuses to Co/Pt multilayers in the SyF reference layer.

  16. Sink efficiency calculation of dislocations in irradiated materials by phase-field modelling

    International Nuclear Information System (INIS)

    Rouchette, Adrien

    2015-01-01

    The aim of this work is to develop a modelling technique for diffusion of crystallographic migrating defects in irradiated metals and absorption by sinks to better predict the microstructural evolution in those materials.The phase field technique is well suited for this problem, since it naturally takes into account the elastic effects of dislocations on point defect diffusion in the most complex cases. The phase field model presented in this work has been adapted to simulate the generation of defects by irradiation and their absorption by the dislocation cores by means of a new order parameter associated to the sink morphology. The method has first been validated in different reference cases by comparing the sink strengths obtained numerically with analytical solutions available in the literature. Then, the method has been applied to dislocations with different orientations in zirconium, taking into account the anisotropic properties of the crystal and point defects, obtained by state-of-the-art atomic calculations.The results show that the shape anisotropy of the point defects promotes the vacancy absorption by basal loops, which is consistent with the experimentally observed zirconium growth under irradiation. Finally, the rigorous investigation of the dislocation loop case proves that phase field simulations give more accurate results than analytical solutions in realistic loop density ranges. (author)

  17. Formulation of probabilistic models of protein structure in atomic detail using the reference ratio method.

    Science.gov (United States)

    Valentin, Jan B; Andreetta, Christian; Boomsma, Wouter; Bottaro, Sandro; Ferkinghoff-Borg, Jesper; Frellsen, Jes; Mardia, Kanti V; Tian, Pengfei; Hamelryck, Thomas

    2014-02-01

    We propose a method to formulate probabilistic models of protein structure in atomic detail, for a given amino acid sequence, based on Bayesian principles, while retaining a close link to physics. We start from two previously developed probabilistic models of protein structure on a local length scale, which concern the dihedral angles in main chain and side chains, respectively. Conceptually, this constitutes a probabilistic and continuous alternative to the use of discrete fragment and rotamer libraries. The local model is combined with a nonlocal model that involves a small number of energy terms according to a physical force field, and some information on the overall secondary structure content. In this initial study we focus on the formulation of the joint model and the evaluation of the use of an energy vector as a descriptor of a protein's nonlocal structure; hence, we derive the parameters of the nonlocal model from the native structure without loss of generality. The local and nonlocal models are combined using the reference ratio method, which is a well-justified probabilistic construction. For evaluation, we use the resulting joint models to predict the structure of four proteins. The results indicate that the proposed method and the probabilistic models show considerable promise for probabilistic protein structure prediction and related applications. Copyright © 2013 Wiley Periodicals, Inc.

  18. A global reference for caesarean section rates (C-Model): a multicountry cross-sectional study.

    Science.gov (United States)

    Souza, J P; Betran, A P; Dumont, A; de Mucio, B; Gibbs Pickens, C M; Deneux-Tharaux, C; Ortiz-Panozo, E; Sullivan, E; Ota, E; Togoobaatar, G; Carroli, G; Knight, H; Zhang, J; Cecatti, J G; Vogel, J P; Jayaratne, K; Leal, M C; Gissler, M; Morisaki, N; Lack, N; Oladapo, O T; Tunçalp, Ö; Lumbiganon, P; Mori, R; Quintana, S; Costa Passos, A D; Marcolin, A C; Zongo, A; Blondel, B; Hernández, B; Hogue, C J; Prunet, C; Landman, C; Ochir, C; Cuesta, C; Pileggi-Castro, C; Walker, D; Alves, D; Abalos, E; Moises, Ecd; Vieira, E M; Duarte, G; Perdona, G; Gurol-Urganci, I; Takahiko, K; Moscovici, L; Campodonico, L; Oliveira-Ciabati, L; Laopaiboon, M; Danansuriya, M; Nakamura-Pereira, M; Costa, M L; Torloni, M R; Kramer, M R; Borges, P; Olkhanud, P B; Pérez-Cuevas, R; Agampodi, S B; Mittal, S; Serruya, S; Bataglia, V; Li, Z; Temmerman, M; Gülmezoglu, A M

    2016-02-01

    To generate a global reference for caesarean section (CS) rates at health facilities. Cross-sectional study. Health facilities from 43 countries. Thirty eight thousand three hundred and twenty-four women giving birth from 22 countries for model building and 10,045,875 women giving birth from 43 countries for model testing. We hypothesised that mathematical models could determine the relationship between clinical-obstetric characteristics and CS. These models generated probabilities of CS that could be compared with the observed CS rates. We devised a three-step approach to generate the global benchmark of CS rates at health facilities: creation of a multi-country reference population, building mathematical models, and testing these models. Area under the ROC curves, diagnostic odds ratio, expected CS rate, observed CS rate. According to the different versions of the model, areas under the ROC curves suggested a good discriminatory capacity of C-Model, with summary estimates ranging from 0.832 to 0.844. The C-Model was able to generate expected CS rates adjusted for the case-mix of the obstetric population. We have also prepared an e-calculator to facilitate use of C-Model (www.who.int/reproductivehealth/publications/maternal_perinatal_health/c-model/en/). This article describes the development of a global reference for CS rates. Based on maternal characteristics, this tool was able to generate an individualised expected CS rate for health facilities or groups of health facilities. With C-Model, obstetric teams, health system managers, health facilities, health insurance companies, and governments can produce a customised reference CS rate for assessing use (and overuse) of CS. The C-Model provides a customized benchmark for caesarean section rates in health facilities and systems. © 2015 World Health Organization; licensed by John Wiley & Sons Ltd on behalf of Royal College of Obstetricians and Gynaecologists.

  19. Performance Guaranteed Inertia Emulation forDiesel-Wind System Feed Microgrid via ModelReference Control

    Energy Technology Data Exchange (ETDEWEB)

    Melin, Alexander M. [ORNL; Zhang, Yichen [University of Tennessee, Knoxville (UTK), Department of Electrical Engineering and Computer Science; Djouadi, Seddik [University of Tennessee, Knoxville (UTK), Department of Electrical Engineering and Computer Science; Olama, Mohammed M. [ORNL

    2017-04-01

    In this paper, a model reference control based inertia emulation strategy is proposed. Desired inertia can be precisely emulated through this control strategy so that guaranteed performance is ensured. A typical frequency response model with parametrical inertia is set to be the reference model. A measurement at a specific location delivers the information of disturbance acting on the diesel-wind system to the referencemodel. The objective is for the speed of the diesel-wind system to track the reference model. Since active power variation is dominantly governed by mechanical dynamics and modes, only mechanical dynamics and states, i.e., a swing-engine-governor system plus a reduced-order wind turbine generator, are involved in the feedback control design. The controller is implemented in a three-phase diesel-wind system feed microgrid. The results show exact synthetic inertia is emulated, leading to guaranteed performance and safety bounds.

  20. Global cross-station assessment of neuro-fuzzy models for estimating daily reference evapotranspiration

    Science.gov (United States)

    Shiri, Jalal; Nazemi, Amir Hossein; Sadraddini, Ali Ashraf; Landeras, Gorka; Kisi, Ozgur; Fard, Ahmad Fakheri; Marti, Pau

    2013-02-01

    SummaryAccurate estimation of reference evapotranspiration is important for irrigation scheduling, water resources management and planning and other agricultural water management issues. In the present paper, the capabilities of generalized neuro-fuzzy models were evaluated for estimating reference evapotranspiration using two separate sets of weather data from humid and non-humid regions of Spain and Iran. In this way, the data from some weather stations in the Basque Country and Valencia region (Spain) were used for training the neuro-fuzzy models [in humid and non-humid regions, respectively] and subsequently, the data from these regions were pooled to evaluate the generalization capability of a general neuro-fuzzy model in humid and non-humid regions. The developed models were tested in stations of Iran, located in humid and non-humid regions. The obtained results showed the capabilities of generalized neuro-fuzzy model in estimating reference evapotranspiration in different climatic zones. Global GNF models calibrated using both non-humid and humid data were found to successfully estimate ET0 in both non-humid and humid regions of Iran (the lowest MAE values are about 0.23 mm for non-humid Iranian regions and 0.12 mm for humid regions). non-humid GNF models calibrated using non-humid data performed much better than the humid GNF models calibrated using humid data in non-humid region while the humid GNF model gave better estimates in humid region.

  1. Field theory and the Standard Model

    Energy Technology Data Exchange (ETDEWEB)

    Dudas, E [Orsay, LPT (France)

    2014-07-01

    This brief introduction to Quantum Field Theory and the Standard Model contains the basic building blocks of perturbation theory in quantum field theory, an elementary introduction to gauge theories and the basic classical and quantum features of the electroweak sector of the Standard Model. Some details are given for the theoretical bias concerning the Higgs mass limits, as well as on obscure features of the Standard Model which motivate new physics constructions.

  2. Field space entanglement entropy, zero modes and Lifshitz models

    Science.gov (United States)

    Huffel, Helmuth; Kelnhofer, Gerald

    2017-12-01

    The field space entanglement entropy of a quantum field theory is obtained by integrating out a subset of its fields. We study an interacting quantum field theory consisting of massless scalar fields on a closed compact manifold M. To this model we associate its Lifshitz dual model. The ground states of both models are invariant under constant shifts. We interpret this invariance as gauge symmetry and subject the models to proper gauge fixing. By applying the heat kernel regularization one can show that the field space entanglement entropies of the massless scalar field model and of its Lifshitz dual are agreeing.

  3. Comparison of the near field/far field model and the advanced reach tool (ART) model V1.5: exposure estimates to benzene during parts washing with mineral spirits.

    Science.gov (United States)

    LeBlanc, Mallory; Allen, Joseph G; Herrick, Robert F; Stewart, James H

    2018-03-01

    The Advanced Reach Tool V1.5 (ART) is a mathematical model for occupational exposures conceptually based on, but implemented differently than, the "classic" Near Field/Far Field (NF/FF) exposure model. The NF/FF model conceptualizes two distinct exposure "zones"; the near field, within approximately 1m of the breathing zone, and the far field, consisting of the rest of the room in which the exposure occurs. ART has been reported to provide "realistic and reasonable worst case" estimates of the exposure distribution. In this study, benzene exposure during the use of a metal parts washer was modeled using ART V1.5, and compared to actual measured workers samples and to NF/FF model results from three previous studies. Next, the exposure concentrations expected to be exceeded 25%, 10% and 5% of the time for the exposure scenario were calculated using ART. Lastly, ART exposure estimates were compared with and without Bayesian adjustment. The modeled parts washing benzene exposure scenario included distinct tasks, e.g. spraying, brushing, rinsing and soaking/drying. Because ART can directly incorporate specific types of tasks that are part of the exposure scenario, the present analysis identified each task's determinants of exposure and performance time, thus extending the work of the previous three studies where the process of parts washing was modeled as one event. The ART 50th percentile exposure estimate for benzene (0.425ppm) more closely approximated the reported measured mean value of 0.50ppm than the NF/FF model estimates of 0.33ppm, 0.070ppm or 0.2ppm obtained from other modeling studies of this exposure scenario. The ART model with the Bayesian analysis provided the closest estimate to the measured value (0.50ppm). ART (with Bayesian adjustment) was then used to assess the 75th, the 90th and 95th percentile exposures, predicting that on randomly selected days during this parts washing exposure scenario, 25% of the benzene exposures would be above 0.70ppm; 10

  4. Factors influencing superimposition error of 3D cephalometric landmarks by plane orientation method using 4 reference points: 4 point superimposition error regression model.

    Science.gov (United States)

    Hwang, Jae Joon; Kim, Kee-Deog; Park, Hyok; Park, Chang Seo; Jeong, Ho-Gul

    2014-01-01

    Superimposition has been used as a method to evaluate the changes of orthodontic or orthopedic treatment in the dental field. With the introduction of cone beam CT (CBCT), evaluating 3 dimensional changes after treatment became possible by superimposition. 4 point plane orientation is one of the simplest ways to achieve superimposition of 3 dimensional images. To find factors influencing superimposition error of cephalometric landmarks by 4 point plane orientation method and to evaluate the reproducibility of cephalometric landmarks for analyzing superimposition error, 20 patients were analyzed who had normal skeletal and occlusal relationship and took CBCT for diagnosis of temporomandibular disorder. The nasion, sella turcica, basion and midpoint between the left and the right most posterior point of the lesser wing of sphenoidal bone were used to define a three-dimensional (3D) anatomical reference co-ordinate system. Another 15 reference cephalometric points were also determined three times in the same image. Reorientation error of each landmark could be explained substantially (23%) by linear regression model, which consists of 3 factors describing position of each landmark towards reference axes and locating error. 4 point plane orientation system may produce an amount of reorientation error that may vary according to the perpendicular distance between the landmark and the x-axis; the reorientation error also increases as the locating error and shift of reference axes viewed from each landmark increases. Therefore, in order to reduce the reorientation error, accuracy of all landmarks including the reference points is important. Construction of the regression model using reference points of greater precision is required for the clinical application of this model.

  5. Specification of a STEP Based Reference Model for Exchange of Robotics Models

    DEFF Research Database (Denmark)

    Haenisch, Jochen; Kroszynski, Uri; Ludwig, Arnold

    robot programming, the descriptions of geometry, kinematics, robotics, dynamics, and controller data using STEP are addressed as major goals of the project.The Project Consortium has now released the "Specificatin of a STEP Based Reference Model for Exchange of Robotics Models" on which a series......ESPRIT Project 6457: "Interoperability of Standards for Robotics in CIME" (InterRob) belongs to the Subprogram "Computer Integrated Manufacturing and Engineering" of ESPRIT, the European Specific Programme for Research and Development in Information Technology supported by the European Commision....... InterRob aims to develop an integrated solution to precision manufacturing by combining product data and database technologies with robotic off-line programming and simulation. Benefits arise from the use of high level simulation tools and developing standards for the exchange of product model data...

  6. A Reference Model for Distribution Grid Control in the 21st Century

    Energy Technology Data Exchange (ETDEWEB)

    Taft, Jeffrey D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); De Martini, Paul [California Inst. of Technology (CalTech), Pasadena, CA (United States); Kristov, Lorenzo [California Independent System Operator, Folsom, CA (United States)

    2015-07-01

    Intensive changes in the structure of the grid due to the penetration of new technologies, coupled with changing societal needs are outpacing the capabilities of traditional grid control systems. The gap is widening at an accelerating rate with the biggest impacts occurring at the distribution level due to the widespread adoption of diverse distribution-connected energy resources (DER) . This paper outlines the emerging distribution grid control environment, defines the new distribution control problem, and provides a distribution control reference model. The reference model offers a schematic representation of the problem domain to inform development of system architecture and control solutions for the high-DER electric system.

  7. Ground Motion Prediction Equations for Western Saudi Arabia from a Reference Model

    Science.gov (United States)

    Kiuchi, R.; Mooney, W. D.; Mori, J. J.; Zahran, H. M.; Al-Raddadi, W.; Youssef, S.

    2017-12-01

    Western Saudi Arabia is surrounded by several active seismic zones such as the Red Sea and the Gulf of Aqaba where a destructive magnitude 7.3 event occurred in 1995. Over the last decade, the Saudi Geological Survey (SGS) has deployed a dense seismic network that has made it possible to monitor seismic activity more accurately. For example, the network has detected multiple seismic swarms beneath the volcanic fields in western Saudi Arabia. The most recent damaging event was a M5.7 earthquake that occurred in 2009 at Harrat Lunayyir. In terms of seismic hazard assessment, Zahran et al. (2015; 2016) presented a Probabilistic Seismic Hazard Assessment (PSHA) for western Saudi Arabia that was developed using published Ground Motion Prediction Equations (GMPEs) from areas outside of Saudi Arabia. In this study, we consider 41 earthquakes of M 3.0 - 5.4, recorded on 124 stations of the SGS network, to create a set of 442 peak ground acceleration (PGA) and peak ground velocity (PGV) records with a range of epicentral distances from 3 km to 400 km. We use the GMPE model BSSA14 (Boore et al., 2014) as a reference model to estimate our own best-fitting coefficients from a regression analysis using the events occurred in western Saudi Arabia. For epicentral distances less than 100 km, our best fitting model has different source scaling in comparison with the GMPE of BSSA14 adjusted for the California region. In addition, our model indicates that the peak amplitudes have less attenuation in western Saudi Arabia than in California.

  8. VBE reference framework

    NARCIS (Netherlands)

    Afsarmanesh, H.; Camarinha-Matos, L.M.; Ermilova, E.; Camarinha-Matos, L.M.; Afsarmanesh, H.; Ollus, M.

    2008-01-01

    Defining a comprehensive and generic "reference framework" for Virtual organizations Breeding Environments (VBEs), addressing all their features and characteristics, is challenging. While the definition and modeling of VBEs has become more formalized during the last five years, "reference models"

  9. Incorporation of detailed eye model into polygon-mesh versions of ICRP-110 reference phantoms.

    Science.gov (United States)

    Nguyen, Thang Tat; Yeom, Yeon Soo; Kim, Han Sung; Wang, Zhao Jun; Han, Min Cheol; Kim, Chan Hyeong; Lee, Jai Ki; Zankl, Maria; Petoussi-Henss, Nina; Bolch, Wesley E; Lee, Choonsik; Chung, Beom Sun

    2015-11-21

    The dose coefficients for the eye lens reported in ICRP 2010 Publication 116 were calculated using both a stylized model and the ICRP-110 reference phantoms, according to the type of radiation, energy, and irradiation geometry. To maintain consistency of lens dose assessment, in the present study we incorporated the ICRP-116 detailed eye model into the converted polygon-mesh (PM) version of the ICRP-110 reference phantoms. After the incorporation, the dose coefficients for the eye lens were calculated and compared with those of the ICRP-116 data. The results showed generally a good agreement between the newly calculated lens dose coefficients and the values of ICRP 2010 Publication 116. Significant differences were found for some irradiation cases due mainly to the use of different types of phantoms. Considering that the PM version of the ICRP-110 reference phantoms preserve the original topology of the ICRP-110 reference phantoms, it is believed that the PM version phantoms, along with the detailed eye model, provide more reliable and consistent dose coefficients for the eye lens.

  10. Field space entanglement entropy, zero modes and Lifshitz models

    Directory of Open Access Journals (Sweden)

    Helmuth Huffel

    2017-12-01

    Full Text Available The field space entanglement entropy of a quantum field theory is obtained by integrating out a subset of its fields. We study an interacting quantum field theory consisting of massless scalar fields on a closed compact manifold M. To this model we associate its Lifshitz dual model. The ground states of both models are invariant under constant shifts. We interpret this invariance as gauge symmetry and subject the models to proper gauge fixing. By applying the heat kernel regularization one can show that the field space entanglement entropies of the massless scalar field model and of its Lifshitz dual are agreeing.

  11. Parameterized source term in the diffusion approximation for enhanced near-field modeling of collimated light

    Science.gov (United States)

    Jia, Mengyu; Wang, Shuang; Chen, Xueying; Gao, Feng; Zhao, Huijuan

    2016-03-01

    Most analytical methods for describing light propagation in turbid medium exhibit low effectiveness in the near-field of a collimated source. Motivated by the Charge Simulation Method in electromagnetic theory as well as the established discrete source based modeling, we have reported on an improved explicit model, referred to as "Virtual Source" (VS) diffuse approximation (DA), to inherit the mathematical simplicity of the DA while considerably extend its validity in modeling the near-field photon migration in low-albedo medium. In this model, the collimated light in the standard DA is analogously approximated as multiple isotropic point sources (VS) distributed along the incident direction. For performance enhancement, a fitting procedure between the calculated and realistic reflectances is adopted in the nearfield to optimize the VS parameters (intensities and locations). To be practically applicable, an explicit 2VS-DA model is established based on close-form derivations of the VS parameters for the typical ranges of the optical parameters. The proposed VS-DA model is validated by comparing with the Monte Carlo simulations, and further introduced in the image reconstruction of the Laminar Optical Tomography system.

  12. Probing the Importance of Charge Flux in Force Field Modeling.

    Science.gov (United States)

    Sedghamiz, Elaheh; Nagy, Balazs; Jensen, Frank

    2017-08-08

    We analyze the conformational dependence of atomic charges and molecular dipole moments for a selection of ∼900 conformations of peptide models of the 20 neutral amino acids. Based on a set of reference density functional theory calculations, we partition the changes into effects due to changes in bond distances, bond angles, and torsional angles and into geometry and charge flux contributions. This allows an assessment of the limitations of fixed charge force fields and indications for how to design improved force fields. The torsional degrees of freedom are the main contribution to conformational changes of atomic charges and molecular dipole moments, but indirect effects due to change in bond distances and angles account for ∼25% of the variation. Charge flux effects dominate for changes in bond distances and are also the main component of the variation in bond angles, while they are ∼25% compared to the geometry variations for torsional degrees of freedom. The geometry and charge flux contributions to some extent produce compensating effects.

  13. Propulsion Physics Under the Changing Density Field Model

    Science.gov (United States)

    Robertson, Glen A.

    2011-01-01

    To grow as a space faring race, future spaceflight systems will requires new propulsion physics. Specifically a propulsion physics model that does not require mass ejection without limiting the high thrust necessary to accelerate within or beyond our solar system and return within a normal work period or lifetime. In 2004 Khoury and Weltman produced a density dependent cosmology theory they called Chameleon Cosmology, as at its nature, it is hidden within known physics. This theory represents a scalar field within and about an object, even in the vacuum. Whereby, these scalar fields can be viewed as vacuum energy fields with definable densities that permeate all matter; having implications to dark matter/energy with universe acceleration properties; implying a new force mechanism for propulsion physics. Using Chameleon Cosmology, the author has developed a new propulsion physics model, called the Changing Density Field (CDF) Model. This model relates to density changes in these density fields, where the density field density changes are related to the acceleration of matter within an object. These density changes in turn change how an object couples to the surrounding density fields. Whereby, thrust is achieved by causing a differential in the coupling to these density fields about an object. Since the model indicates that the density of the density field in an object can be changed by internal mass acceleration, even without exhausting mass, the CDF model implies a new propellant-less propulsion physics model

  14. Mars Global Reference Atmospheric Model 2010 Version: Users Guide

    Science.gov (United States)

    Justh, H. L.

    2014-01-01

    This Technical Memorandum (TM) presents the Mars Global Reference Atmospheric Model 2010 (Mars-GRAM 2010) and its new features. Mars-GRAM is an engineering-level atmospheric model widely used for diverse mission applications. Applications include systems design, performance analysis, and operations planning for aerobraking, entry, descent and landing, and aerocapture. Additionally, this TM includes instructions on obtaining the Mars-GRAM source code and data files as well as running Mars-GRAM. It also contains sample Mars-GRAM input and output files and an example of how to incorporate Mars-GRAM as an atmospheric subroutine in a trajectory code.

  15. The random field Blume-Capel model revisited

    Science.gov (United States)

    Santos, P. V.; da Costa, F. A.; de Araújo, J. M.

    2018-04-01

    We have revisited the mean-field treatment for the Blume-Capel model under the presence of a discrete random magnetic field as introduced by Kaufman and Kanner (1990). The magnetic field (H) versus temperature (T) phase diagrams for given values of the crystal field D were recovered in accordance to Kaufman and Kanner original work. However, our main goal in the present work was to investigate the distinct structures of the crystal field versus temperature phase diagrams as the random magnetic field is varied because similar models have presented reentrant phenomenon due to randomness. Following previous works we have classified the distinct phase diagrams according to five different topologies. The topological structure of the phase diagrams is maintained for both H - T and D - T cases. Although the phase diagrams exhibit a richness of multicritical phenomena we did not found any reentrant effect as have been seen in similar models.

  16. Interaction quench dynamics in the Kondo model in the presence of a local magnetic field.

    Science.gov (United States)

    Heyl, M; Kehrein, S

    2010-09-01

    In this work we investigate the quench dynamics in the Kondo model on the Toulouse line in the presence of a local magnetic field. It is shown that this setup can be realized by either applying the local magnetic field directly or by preparing the system in a macroscopically spin-polarized initial state. In the latter case, the magnetic field results from a subtlety in applying the bosonization technique where terms that are usually referred to as finite-size corrections become important in the present non-equilibrium setting. The transient dynamics are studied by analyzing exact analytical results for the local spin dynamics. The timescale for the relaxation of the local dynamical quantities turns out to be exclusively determined by the Kondo scale. In the transient regime, one observes damped oscillations in the local correlation functions with a frequency set by the magnetic field.

  17. Astrophysical constraints on scalar field models

    International Nuclear Information System (INIS)

    Bertolami, O.; Paramos, J.

    2005-01-01

    We use stellar structure dynamics arguments to extract bounds on the relevant parameters of two scalar field models: the putative scalar field mediator of a fifth force with a Yukawa potential and the new variable mass particle models. We also analyze the impact of a constant solar inbound acceleration, such as the one reported by the Pioneer anomaly, on stellar astrophysics. We consider the polytropic gas model to estimate the effect of these models on the hydrostatic equilibrium equation and fundamental quantities such as the central temperature. The current bound on the solar luminosity is used to constrain the relevant parameters of each model

  18. Virtual-source diffusion approximation for enhanced near-field modeling of photon-migration in low-albedo medium.

    Science.gov (United States)

    Jia, Mengyu; Chen, Xueying; Zhao, Huijuan; Cui, Shanshan; Liu, Ming; Liu, Lingling; Gao, Feng

    2015-01-26

    Most analytical methods for describing light propagation in turbid medium exhibit low effectiveness in the near-field of a collimated source. Motivated by the Charge Simulation Method in electromagnetic theory as well as the established discrete source based modeling, we herein report on an improved explicit model for a semi-infinite geometry, referred to as "Virtual Source" (VS) diffuse approximation (DA), to fit for low-albedo medium and short source-detector separation. In this model, the collimated light in the standard DA is analogously approximated as multiple isotropic point sources (VS) distributed along the incident direction. For performance enhancement, a fitting procedure between the calculated and realistic reflectances is adopted in the near-field to optimize the VS parameters (intensities and locations). To be practically applicable, an explicit 2VS-DA model is established based on close-form derivations of the VS parameters for the typical ranges of the optical parameters. This parameterized scheme is proved to inherit the mathematical simplicity of the DA approximation while considerably extending its validity in modeling the near-field photon migration in low-albedo medium. The superiority of the proposed VS-DA method to the established ones is demonstrated in comparison with Monte-Carlo simulations over wide ranges of the source-detector separation and the medium optical properties.

  19. An associative model of adaptive inference for learning word-referent mappings.

    Science.gov (United States)

    Kachergis, George; Yu, Chen; Shiffrin, Richard M

    2012-04-01

    People can learn word-referent pairs over a short series of individually ambiguous situations containing multiple words and referents (Yu & Smith, 2007, Cognition 106: 1558-1568). Cross-situational statistical learning relies on the repeated co-occurrence of words with their intended referents, but simple co-occurrence counts cannot explain the findings. Mutual exclusivity (ME: an assumption of one-to-one mappings) can reduce ambiguity by leveraging prior experience to restrict the number of word-referent pairings considered but can also block learning of non-one-to-one mappings. The present study first trained learners on one-to-one mappings with varying numbers of repetitions. In late training, a new set of word-referent pairs were introduced alongside pretrained pairs; each pretrained pair consistently appeared with a new pair. Results indicate that (1) learners quickly infer new pairs in late training on the basis of their knowledge of pretrained pairs, exhibiting ME; and (2) learners also adaptively relax the ME bias and learn two-to-two mappings involving both pretrained and new words and objects. We present an associative model that accounts for both results using competing familiarity and uncertainty biases.

  20. DRAPING OF THE INTERSTELLAR MAGNETIC FIELD OVER THE HELIOPAUSE: A PASSIVE FIELD MODEL

    International Nuclear Information System (INIS)

    Isenberg, Philip A.; Forbes, Terry G.; Möbius, Eberhard

    2015-01-01

    As the local interstellar plasma flows past our heliosphere, it is slowed and deflected around the magnetic obstacle of the heliopause. The interstellar magnetic field, frozen into this plasma, then becomes draped around the heliopause in a characteristic manner. We derive the analytical solution for this draped magnetic field in the limit of weak field intensity, assuming an ideal potential flow around the heliopause, which we model as a Rankine half-body. We compare the structure of the model magnetic field with observed properties of the Interstellar Boundary Explorer (IBEX) ribbon and with in situ observations at the Voyager 1 spacecraft. We find reasonable qualitative agreement, given the idealizations of the model. This agreement lends support to the secondary ENA model of the IBEX ribbon and to the interpretation that Voyager 1 has crossed the heliopause. We also predict that the magnetic field measured by Voyager 2 after it crosses the heliopause will not be significantly rotated away from the direction of the undisturbed interstellar field

  1. Post-processing scheme for modelling the lithospheric magnetic field

    Directory of Open Access Journals (Sweden)

    V. Lesur

    2013-03-01

    Full Text Available We investigated how the noise in satellite magnetic data affects magnetic lithospheric field models derived from these data in the special case where this noise is correlated along satellite orbit tracks. For this we describe the satellite data noise as a perturbation magnetic field scaled independently for each orbit, where the scaling factor is a random variable, normally distributed with zero mean. Under this assumption, we have been able to derive a model for errors in lithospheric models generated by the correlated satellite data noise. Unless the perturbation field is known, estimating the noise in the lithospheric field model is a non-linear inverse problem. We therefore proposed an iterative post-processing technique to estimate both the lithospheric field model and its associated noise model. The technique has been successfully applied to derive a lithospheric field model from CHAMP satellite data up to spherical harmonic degree 120. The model is in agreement with other existing models. The technique can, in principle, be extended to all sorts of potential field data with "along-track" correlated errors.

  2. Business process modelling in demand-driven agri-food supply chains : a reference framework

    NARCIS (Netherlands)

    Verdouw, C.N.

    2010-01-01

    Keywords: Business process models; Supply chain management; Information systems; Reference information models; Market orientation; Mass customisation; Configuration; Coordination; Control; SCOR; Pot plants; Fruit industry

    Abstract

    The increasing volatility and diversity of

  3. On unified field theories, dynamical torsion and geometrical models: II

    International Nuclear Information System (INIS)

    Cirilo-Lombardo, D.J.

    2011-01-01

    We analyze in this letter the same space-time structure as that presented in our previous reference (Part. Nucl, Lett. 2010. V.7, No.5. P.299-307), but relaxing now the condition a priori of the existence of a potential for the torsion. We show through exact cosmological solutions from this model, where the geometry is Euclidean RxO 3 ∼ RxSU(2), the relation between the space-time geometry and the structure of the gauge group. Precisely this relation is directly connected with the relation of the spin and torsion fields. The solution of this model is explicitly compared with our previous ones and we find that: i) the torsion is not identified directly with the Yang-Mills type strength field, ii) there exists a compatibility condition connected with the identification of the gauge group with the geometric structure of the space-time: this fact leads to the identification between derivatives of the scale factor a with the components of the torsion in order to allow the Hosoya-Ogura ansatz (namely, the alignment of the isospin with the frame geometry of the space-time), and iii) of two possible structures of the torsion the 'tratorial' form (the only one studied here) forbid wormhole configurations, leading only to cosmological instanton space-time in eternal expansion

  4. Three-dimensional temperature field model of thermally decomposing resin composite irradiated by laser

    International Nuclear Information System (INIS)

    Chen Minsun; Jiang Houman; Liu Zejin

    2011-01-01

    Fundamental equations governing the temperature field of thermally decomposing resin composite irradiated by laser are derived from mass and energy conservation laws with the control Janume method. The thermal decomposition of resin is described by a multi-step model. An assumption is proposed that the flow of pyrolysis gas is one-dimensional, which makes it possible to consider the influence of pyrolysis gas convective transport and realize the closure of the three-dimensional model without introducing mechanical quantities. In view of the anisotropy of resin composite, expressions of the thermal conductivities of partially pyrolyzed material are deduced, as well as the computing formula for the laser absorption coefficient of partially pyrolyzed material. The energy conservation equation is consistent with reference under some simplifications. (authors)

  5. The Swarm Initial Field Model for the 2014 geomagnetic field

    DEFF Research Database (Denmark)

    Olsen, Nils; Hulot, Gauthier; Lesur, Vincent

    2015-01-01

    agreement (up to at least degree 60) with recent field models derived from CHAMP data, providing an initial validation of the quality of the Swarm magnetic measurements. Use of gradient data improves the determination of both the static field and its secular variation, with the mean misfit for East...

  6. Initial geomagnetic field model from Magsat vector data

    Science.gov (United States)

    Langel, R. A.; Mead, G. D.; Lancaster, E. R.; Estes, R. H.; Fabiano, E. B.

    1980-01-01

    Magsat data from the magnetically quiet days of November 5-6, 1979, were used to derive a thirteenth degree and order spherical harmonic geomagnetic field model, MGST(6/80). The model utilized both scalar and high-accuracy vector data and fit that data with root-mean-square deviations of 8.2, 6.9, 7.6 and 7.4 nT for the scalar magnitude, B(r), B(theta), and B(phi), respectively. The model includes the three first-order coefficients of the external field. Comparison with averaged Dst indicates that zero Dst corresponds with 25 nT of horizontal field from external sources. When compared with earlier models, the earth's dipole moment continues to decrease at a rate of about 26 nT/yr. Evaluation of earlier models with Magsat data shows that the scalar field at the Magsat epoch is best predicted by the POGO(2/72) model but that the WC80, AWC/75 and IGS/75 are better for predicting vector fields.

  7. Flow field mapping in data rack model

    Directory of Open Access Journals (Sweden)

    Matěcha J.

    2013-04-01

    Full Text Available The main objective of this study was to map the flow field inside the data rack model, fitted with three 1U server models. The server model is based on the common four-processor 1U server. The main dimensions of the data rack model geometry are taken fully from the real geometry. Only the model was simplified with respect to the greatest possibility in the experimental measurements. The flow field mapping was carried out both experimentally and numerically. PIV (Particle Image Velocimetry method was used for the experimental flow field mapping, when the flow field has been mapped for defined regions within the 2D/3D data rack model. Ansys CFX and OpenFOAM software were used for the numerical solution. Boundary conditions for numerical model were based on data obtained from experimental measurement of velocity profile at the output of the server mockup. This velocity profile was used as the input boundary condition in the calculation. In order to achieve greater consistency of the numerical model with experimental data, the numerical model was modified with regard to the results of experimental measurements. Results from the experimental and numerical measurements were compared and the areas of disparateness were identified. In further steps the obtained proven numerical model will be utilized for the real geometry of data racks and data.

  8. Empirical high-latitude electric field models

    International Nuclear Information System (INIS)

    Heppner, J.P.; Maynard, N.C.

    1987-01-01

    Electric field measurements from the Dynamics Explorer 2 satellite have been analyzed to extend the empirical models previously developed from dawn-dusk OGO 6 measurements (J.P. Heppner, 1977). The analysis embraces large quantities of data from polar crossings entering and exiting the high latitudes in all magnetic local time zones. Paralleling the previous analysis, the modeling is based on the distinctly different polar cap and dayside convective patterns that occur as a function of the sign of the Y component of the interplanetary magnetic field. The objective, which is to represent the typical distributions of convective electric fields with a minimum number of characteristic patterns, is met by deriving one pattern (model BC) for the northern hemisphere with a +Y interplanetary magnetic field (IMF) and southern hemisphere with a -Y IMF and two patterns (models A and DE) for the northern hemisphere with a -Y IMF and southern hemisphere with a +Y IMF. The most significant large-scale revisions of the OGO 6 models are (1) on the dayside where the latitudinal overlap of morning and evening convection cells reverses with the sign of the IMF Y component, (2) on the nightside where a westward flow region poleward from the Harang discontinuity appears under model BC conditions, and (3) magnetic local time shifts in the positions of the convection cell foci. The modeling above was followed by a detailed examination of cases where the IMF Z component was clearly positive (northward). Neglecting the seasonally dependent cases where irregularities obscure pattern recognition, the observations range from reasonable agreement with the new BC and DE models, to cases where different characteristics appeared primarily at dayside high latitudes

  9. Renormalization of gauge fields models

    International Nuclear Information System (INIS)

    Becchi, C.; Rouet, A.; Stora, R.

    1974-01-01

    A new approach to gauge field models is described. It is based on the Bogoliubov-Parasiuk-Hepp-Zimmermann (BPHZ) renormalization scheme making extensive use of the quantum action principle, and the Slavnov invariance. The quantum action principle being first summarized in the framework of the BPHZ is then applied to a global symmetry problem. The symmetry property of the gauge field Lagrangians in the tree approximation is exhibited, and the preservation of this property at the quantum level is discussed. The main results relative to the Abelian and SU(2) Higgs-Kibble models are briefly reviewed [fr

  10. Dipole-magnet field models based on a conformal map

    Directory of Open Access Journals (Sweden)

    P. L. Walstrom

    2012-10-01

    Full Text Available In general, generation of charged-particle transfer maps for conventional iron-pole-piece dipole magnets to third and higher order requires a model for the midplane field profile and its transverse derivatives (soft-edge model to high order and numerical integration of map coefficients. An exact treatment of the problem for a particular magnet requires use of measured magnetic data. However, in initial design of beam transport systems, users of charged-particle optics codes generally rely on magnet models built into the codes. Indeed, if maps to third order are adequate for the problem, an approximate analytic field model together with numerical map coefficient integration can capture the important features of the transfer map. The model described in this paper is based on the fact that, except at very large distances from the magnet, the magnetic field for parallel pole-face magnets with constant pole gap height and wide pole faces is basically two dimensional (2D. The field for all space outside of the pole pieces is given by a single (complex analytic expression and includes a parameter that controls the rate of falloff of the fringe field. Since the field function is analytic in the complex plane outside of the pole pieces, it satisfies two basic requirements of a field model for higher-order map codes: it is infinitely differentiable at the midplane and also a solution of the Laplace equation. It is apparently the only simple model available that combines an exponential approach to the central field with an inverse cubic falloff of field at large distances from the magnet in a single expression. The model is not intended for detailed fitting of magnetic field data, but for use in numerical map-generating codes for studying the effect of extended fringe fields on higher-order transfer maps. It is based on conformally mapping the area between the pole pieces to the upper half plane, and placing current filaments on the pole faces. An

  11. Student's vacation travel: a reference dependent model of airline fares preferences

    NARCIS (Netherlands)

    Grigolon, A.B.; Kemperman, A.D.A.M.; Timmermans, H.J.P.

    2012-01-01

    This article reports the results of student vacation travel choice analysis using a reference dependent model of airline fare preferences. Findings suggests, as expected, that the preferences/utility decreases with increasing levels of cost. The evaluation of the airfare, however, becomes

  12. Children and adults exposed to electromagnetic fields at the ICNIRP reference levels: Theoretical assessment of the induced peak temperature increase

    NARCIS (Netherlands)

    J. Bakker (Jan); M.M. Paulides (Maarten); E. Neufeld; A. Christ (A.); N. Kuster (Niels); G.C. van Rhoon (Gerard)

    2011-01-01

    textabstractTo avoid potentially adverse health effects of electromagnetic fields (EMF), the International Commission on Non-Ionizing Radiation Protection (ICNIRP) has defined EMF reference levels. Restrictions on induced whole-body-averaged specific absorption rate (SAR wb) are provided to keep the

  13. EIA model documentation: World oil refining logistics demand model,''WORLD'' reference manual

    International Nuclear Information System (INIS)

    1994-01-01

    This manual is intended primarily for use as a reference by analysts applying the WORLD model to regional studies. It also provides overview information on WORLD features of potential interest to managers and analysts. Broadly, the manual covers WORLD model features in progressively increasing detail. Section 2 provides an overview of the WORLD model, how it has evolved, what its design goals are, what it produces, and where it can be taken with further enhancements. Section 3 reviews model management covering data sources, managing over-optimization, calibration and seasonality, check-points for case construction and common errors. Section 4 describes in detail the WORLD system, including: data and program systems in overview; details of mainframe and PC program control and files;model generation, size management, debugging and error analysis; use with different optimizers; and reporting and results analysis. Section 5 provides a detailed description of every WORLD model data table, covering model controls, case and technology data. Section 6 goes into the details of WORLD matrix structure. It provides an overview, describes how regional definitions are controlled and defines the naming conventions for-all model rows, columns, right-hand sides, and bounds. It also includes a discussion of the formulation of product blending and specifications in WORLD. Several Appendices supplement the main sections

  14. MHD turbulence models for the reversed field pinch

    International Nuclear Information System (INIS)

    Gimblett, C.G.; Watkins, M.L.

    1976-01-01

    A kinematic model which describes the effect of isotropic, non-mirror symmetric turbulence on a mean magnetic field is used to examine the temporal behaviour of magnetic field in high beta pinch experiments. Solutions to the model can indicate the formation of a steady-state, force-free configuration that corresponds to the state of lowest magnetic energy and the reversal of the toroidal magnetic field at the plasma boundary in accordance with experimental observations on toroidal pinches such as ZETA and HBTX. This model neglects both the dynamic interaction between fluid and field and the associated anisotropy. These effects are examined in a further model. (author)

  15. Land-Use History and Contemporary Management Inform an Ecological Reference Model for Longleaf Pine Woodland Understory Plant Communities.

    Energy Technology Data Exchange (ETDEWEB)

    Brudvig, Lars A. [Department of Plant Biology, Michigan State University; Orrock, John L. [Department of Zoology, University of Wisconsin; Damschen, Ellen I. [Department of Zoology, University of Wisconsin; et al, et al

    2014-01-23

    Ecological restoration is frequently guided by reference conditions describing a successfully restored ecosystem; however, the causes and magnitude of ecosystem degradation vary, making simple knowledge of reference conditions insufficient for prioritizing and guiding restoration. Ecological reference models provide further guidance by quantifying reference conditions, as well as conditions at degraded states that deviate from reference conditions. Many reference models remain qualitative, however, limiting their utility. We quantified and evaluated a reference model for southeastern U.S. longleaf pine woodland understory plant communities. We used regression trees to classify 232 longleaf pine woodland sites at three locations along the Atlantic coastal plain based on relationships between understory plant community composition, soils lol(which broadly structure these communities), and factors associated with understory degradation, including fire frequency, agricultural history, and tree basal area. To understand the spatial generality of this model, we classified all sites together. and for each of three study locations separately. Both the regional and location-specific models produced quantifiable degradation gradients–i.e., progressive deviation from conditions at 38 reference sites, based on understory species composition, diversity and total cover, litter depth, and other attributes. Regionally, fire suppression was the most important degrading factor, followed by agricultural history, but at individual locations, agricultural history or tree basal area was most important. At one location, the influence of a degrading factor depended on soil attributes. We suggest that our regional model can help prioritize longleaf pine woodland restoration across our study region; however, due to substantial landscape-to-landscape variation, local management decisions should take into account additional factors (e.g., soil attributes). Our study demonstrates the utility

  16. Land-Use History and Contemporary Management Inform an Ecological Reference Model for Longleaf Pine Woodland Understory Plant Communities

    Science.gov (United States)

    Brudvig, Lars A.; Orrock, John L.; Damschen, Ellen I.; Collins, Cathy D.; Hahn, Philip G.; Mattingly, W. Brett; Veldman, Joseph W.; Walker, Joan L.

    2014-01-01

    Ecological restoration is frequently guided by reference conditions describing a successfully restored ecosystem; however, the causes and magnitude of ecosystem degradation vary, making simple knowledge of reference conditions insufficient for prioritizing and guiding restoration. Ecological reference models provide further guidance by quantifying reference conditions, as well as conditions at degraded states that deviate from reference conditions. Many reference models remain qualitative, however, limiting their utility. We quantified and evaluated a reference model for southeastern U.S. longleaf pine woodland understory plant communities. We used regression trees to classify 232 longleaf pine woodland sites at three locations along the Atlantic coastal plain based on relationships between understory plant community composition, soils (which broadly structure these communities), and factors associated with understory degradation, including fire frequency, agricultural history, and tree basal area. To understand the spatial generality of this model, we classified all sites together and for each of three study locations separately. Both the regional and location-specific models produced quantifiable degradation gradients–i.e., progressive deviation from conditions at 38 reference sites, based on understory species composition, diversity and total cover, litter depth, and other attributes. Regionally, fire suppression was the most important degrading factor, followed by agricultural history, but at individual locations, agricultural history or tree basal area was most important. At one location, the influence of a degrading factor depended on soil attributes. We suggest that our regional model can help prioritize longleaf pine woodland restoration across our study region; however, due to substantial landscape-to-landscape variation, local management decisions should take into account additional factors (e.g., soil attributes). Our study demonstrates the utility of

  17. Land-use history and contemporary management inform an ecological reference model for longleaf pine woodland understory plant communities.

    Directory of Open Access Journals (Sweden)

    Lars A Brudvig

    Full Text Available Ecological restoration is frequently guided by reference conditions describing a successfully restored ecosystem; however, the causes and magnitude of ecosystem degradation vary, making simple knowledge of reference conditions insufficient for prioritizing and guiding restoration. Ecological reference models provide further guidance by quantifying reference conditions, as well as conditions at degraded states that deviate from reference conditions. Many reference models remain qualitative, however, limiting their utility. We quantified and evaluated a reference model for southeastern U.S. longleaf pine woodland understory plant communities. We used regression trees to classify 232 longleaf pine woodland sites at three locations along the Atlantic coastal plain based on relationships between understory plant community composition, soils (which broadly structure these communities, and factors associated with understory degradation, including fire frequency, agricultural history, and tree basal area. To understand the spatial generality of this model, we classified all sites together and for each of three study locations separately. Both the regional and location-specific models produced quantifiable degradation gradients-i.e., progressive deviation from conditions at 38 reference sites, based on understory species composition, diversity and total cover, litter depth, and other attributes. Regionally, fire suppression was the most important degrading factor, followed by agricultural history, but at individual locations, agricultural history or tree basal area was most important. At one location, the influence of a degrading factor depended on soil attributes. We suggest that our regional model can help prioritize longleaf pine woodland restoration across our study region; however, due to substantial landscape-to-landscape variation, local management decisions should take into account additional factors (e.g., soil attributes. Our study demonstrates

  18. Auralization of vibroacoustic models in engineering using Wave Field Synthesis: Application to plates and transmission loss

    Science.gov (United States)

    Bolduc, A.; Gauthier, P.-A.; Berry, A.

    2017-12-01

    While perceptual evaluation and sound quality testing with jury are now recognized as essential parts of acoustical product development, they are rarely implemented with spatial sound field reproduction. Instead, monophonic, stereophonic or binaural presentations are used. This paper investigates the workability and interest of a method to use complete vibroacoustic engineering models for auralization based on 2.5D Wave Field Synthesis (WFS). This method is proposed in order that spatial characteristics such as directivity patterns and direction-of-arrival are part of the reproduced sound field while preserving the model complete formulation that coherently combines frequency and spatial responses. Modifications to the standard 2.5D WFS operators are proposed for extended primary sources, affecting the reference line definition and compensating for out-of-plane elementary primary sources. Reported simulations and experiments of reproductions of two physically-accurate vibroacoustic models of thin plates show that the proposed method allows for an effective reproduction in the horizontal plane: Spatial and frequency domains features are recreated. Application of the method to the sound rendering of a virtual transmission loss measurement setup shows the potential of the method for use in virtual acoustical prototyping for jury testing.

  19. Arbitrary scalar-field and quintessence cosmological models

    International Nuclear Information System (INIS)

    Harko, Tiberiu; Lobo, Francisco S.N.; Mak, M.K.

    2014-01-01

    The mechanism of the initial inflationary scenario of the Universe and of its late-time acceleration can be described by assuming the existence of some gravitationally coupled scalar fields φ, with the inflaton field generating inflation and the quintessence field being responsible for the late accelerated expansion. Various inflationary and late-time accelerated scenarios are distinguished by the choice of an effective self-interaction potential V(φ), which simulates a temporarily non-vanishing cosmological term. In this work, we present a new formalism for the analysis of scalar fields in flat isotropic and homogeneous cosmological models. The basic evolution equation of the models can be reduced to a first-order non-linear differential equation. Approximate solutions of this equation can be constructed in the limiting cases of the scalar-field kinetic energy and potential energy dominance, respectively, as well as in the intermediate regime. Moreover, we present several new accelerating and decelerating exact cosmological solutions, based on the exact integration of the basic evolution equation for scalar-field cosmologies. More specifically, exact solutions are obtained for exponential, generalized cosine hyperbolic, and power-law potentials, respectively. Cosmological models with power-law scalar field potentials are also analyzed in detail. (orig.)

  20. Circular Conditional Autoregressive Modeling of Vector Fields.

    Science.gov (United States)

    Modlin, Danny; Fuentes, Montse; Reich, Brian

    2012-02-01

    As hurricanes approach landfall, there are several hazards for which coastal populations must be prepared. Damaging winds, torrential rains, and tornadoes play havoc with both the coast and inland areas; but, the biggest seaside menace to life and property is the storm surge. Wind fields are used as the primary forcing for the numerical forecasts of the coastal ocean response to hurricane force winds, such as the height of the storm surge and the degree of coastal flooding. Unfortunately, developments in deterministic modeling of these forcings have been hindered by computational expenses. In this paper, we present a multivariate spatial model for vector fields, that we apply to hurricane winds. We parameterize the wind vector at each site in polar coordinates and specify a circular conditional autoregressive (CCAR) model for the vector direction, and a spatial CAR model for speed. We apply our framework for vector fields to hurricane surface wind fields for Hurricane Floyd of 1999 and compare our CCAR model to prior methods that decompose wind speed and direction into its N-S and W-E cardinal components.

  1. Large-scale modeling of rain fields from a rain cell deterministic model

    Science.gov (United States)

    FéRal, Laurent; Sauvageot, Henri; Castanet, Laurent; Lemorton, JoëL.; Cornet, FréDéRic; Leconte, Katia

    2006-04-01

    A methodology to simulate two-dimensional rain rate fields at large scale (1000 × 1000 km2, the scale of a satellite telecommunication beam or a terrestrial fixed broadband wireless access network) is proposed. It relies on a rain rate field cellular decomposition. At small scale (˜20 × 20 km2), the rain field is split up into its macroscopic components, the rain cells, described by the Hybrid Cell (HYCELL) cellular model. At midscale (˜150 × 150 km2), the rain field results from the conglomeration of rain cells modeled by HYCELL. To account for the rain cell spatial distribution at midscale, the latter is modeled by a doubly aggregative isotropic random walk, the optimal parameterization of which is derived from radar observations at midscale. The extension of the simulation area from the midscale to the large scale (1000 × 1000 km2) requires the modeling of the weather frontal area. The latter is first modeled by a Gaussian field with anisotropic covariance function. The Gaussian field is then turned into a binary field, giving the large-scale locations over which it is raining. This transformation requires the definition of the rain occupation rate over large-scale areas. Its probability distribution is determined from observations by the French operational radar network ARAMIS. The coupling with the rain field modeling at midscale is immediate whenever the large-scale field is split up into midscale subareas. The rain field thus generated accounts for the local CDF at each point, defining a structure spatially correlated at small scale, midscale, and large scale. It is then suggested that this approach be used by system designers to evaluate diversity gain, terrestrial path attenuation, or slant path attenuation for different azimuth and elevation angle directions.

  2. Phase transitions in the random field Ising model in the presence of a transverse field

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, A.; Chakrabarti, B.K. [Saha Institute of Nuclear Physics, Bidhannagar, Calcutta (India); Stinchcombe, R.B. [Saha Institute of Nuclear Physics, Bidhannagar, Calcutta (India); Department of Physics, Oxford (United Kingdom)

    1996-09-07

    We have studied the phase transition behaviour of the random field Ising model in the presence of a transverse (or tunnelling) field. The mean field phase diagram has been studied in detail, and in particular the nature of the transition induced by the tunnelling (transverse) field at zero temperature. Modified hyper-scaling relation for the zero-temperature transition has been derived using the Suzuki-Trotter formalism and a modified 'Harris criterion'. Mapping of the model to a randomly diluted antiferromagnetic Ising model in uniform longitudinal and transverse field is also given. (author)

  3. Geostatistical methods applied to field model residuals

    DEFF Research Database (Denmark)

    Maule, Fox; Mosegaard, K.; Olsen, Nils

    consists of measurement errors and unmodelled signal), and is typically assumed to be uncorrelated and Gaussian distributed. We have applied geostatistical methods to analyse the residuals of the Oersted(09d/04) field model [http://www.dsri.dk/Oersted/Field_models/IGRF_2005_candidates/], which is based...

  4. A cavitation model based on Eulerian stochastic fields

    Science.gov (United States)

    Magagnato, F.; Dumond, J.

    2013-12-01

    Non-linear phenomena can often be described using probability density functions (pdf) and pdf transport models. Traditionally the simulation of pdf transport requires Monte-Carlo codes based on Lagrangian "particles" or prescribed pdf assumptions including binning techniques. Recently, in the field of combustion, a novel formulation called the stochastic-field method solving pdf transport based on Eulerian fields has been proposed which eliminates the necessity to mix Eulerian and Lagrangian techniques or prescribed pdf assumptions. In the present work, for the first time the stochastic-field method is applied to multi-phase flow and in particular to cavitating flow. To validate the proposed stochastic-field cavitation model, two applications are considered. Firstly, sheet cavitation is simulated in a Venturi-type nozzle. The second application is an innovative fluidic diode which exhibits coolant flashing. Agreement with experimental results is obtained for both applications with a fixed set of model constants. The stochastic-field cavitation model captures the wide range of pdf shapes present at different locations.

  5. High-performance phase-field modeling

    KAUST Repository

    Vignal, Philippe

    2015-04-27

    Many processes in engineering and sciences involve the evolution of interfaces. Among the mathematical frameworks developed to model these types of problems, the phase-field method has emerged as a possible solution. Phase-fields nonetheless lead to complex nonlinear, high-order partial differential equations, whose solution poses mathematical and computational challenges. Guaranteeing some of the physical properties of the equations has lead to the development of efficient algorithms and discretizations capable of recovering said properties by construction [2, 5]. This work builds-up on these ideas, and proposes novel discretization strategies that guarantee numerical energy dissipation for both conserved and non-conserved phase-field models. The temporal discretization is based on a novel method which relies on Taylor series and ensures strong energy stability. It is second-order accurate, and can also be rendered linear to speed-up the solution process [4]. The spatial discretization relies on Isogeometric Analysis, a finite element method that possesses the k-refinement technology and enables the generation of high-order, high-continuity basis functions. These basis functions are well suited to handle the high-order operators present in phase-field models. Two-dimensional and three dimensional results of the Allen-Cahn, Cahn-Hilliard, Swift-Hohenberg and phase-field crystal equation will be presented, which corroborate the theoretical findings, and illustrate the robustness of the method. Results related to more challenging examples, namely the Navier-Stokes Cahn-Hilliard and a diusion-reaction Cahn-Hilliard system, will also be presented. The implementation was done in PetIGA and PetIGA-MF, high-performance Isogeometric Analysis frameworks [1, 3], designed to handle non-linear, time-dependent problems.

  6. U.S. Department of Energy Reference Model Program RM1: Experimental Results

    Energy Technology Data Exchange (ETDEWEB)

    Hill, Craig [Univ. of Minnesota, Minneapolis, MN (United States); Neary, Vincent Sinclair [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Gunawan, Budi [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Guala, Michele [Univ. of Minnesota, Minneapolis, MN (United States); Sotiropoulos, Fotis [Univ. of Minnesota, Minneapolis, MN (United States)

    2014-10-01

    The Reference Model Project (RMP), sponsored by the U.S. Department of Energy’s (DOE) Wind and Water Power Technologies Program within the Office of Energy Efficiency & Renewable Energy (EERE), aims at expediting industry growth and efficiency by providing non-proprietary Reference Models (RM) of MHK technology designs as study objects for open-source research and development (Neary et al. 2014a,b). As part of this program, MHK turbine models were tested in a large open channel facility at the University of Minnesota’s St. Anthony Falls Laboratory (UMN-SAFL). Reference Model 1 (RM2) is a 1:40 geometric scale dual-rotor axial flow horizontal axis device with counter-rotating rotors, each with a rotor diameter dT = 0.5m. Precise blade angular position and torque measurements were synchronized with three acoustic Doppler velocimeters (ADVs) aligned with each rotor and the midpoint for RM1. Flow conditions for each case were controlled such that depth, h = 1m, and volumetric flow rate, Qw = 2.425m3s-1, resulting in a hub height velocity of approximately Uhub = 1.05ms-1 and blade chord length Reynolds numbers of Rec ≈ 3.0x105. Vertical velocity profiles collected in the wake of each device from 1 to 10 rotor diameters are used to estimate the velocity recovery and turbulent characteristics in the wake, as well as the interaction of the counter-rotating rotor wakes. The development of this high resolution laboratory investigation provides a robust dataset that enables assessing turbulence performance models and their ability to accurately predict device performance metrics, including computational fluid dynamics (CFD) models that can be used to predict turbulent inflow environments, reproduce wake velocity deficit, recovery and higher order turbulent statistics, as well as device performance metrics.

  7. U.S. Department of Energy Reference Model Program RM1: Experimental Results.

    Energy Technology Data Exchange (ETDEWEB)

    Hill, Craig [Univ. of Minnesota, Minneapolis, MN (United States); Neary, Vincent Sinclair [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Gunawan, Budi [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Guala, Michele [Univ. of Minnesota, Minneapolis, MN (United States); Sotiropoulos, Fotis [Univ. of Minnesota, Minneapolis, MN (United States)

    2017-08-01

    The Reference Model Project (RMP), sponsored by the U.S. Department of Energy’s (DOE) Wind and Water Power Technologies Program within the Office of Energy Efficiency & Renewable Energy (EERE), aims at expediting industry growth and efficiency by providing nonproprietary Reference Models (RM) of MHK technology designs as study objects for opensource research and development (Neary et al. 2014a,b). As part of this program, MHK turbine models were tested in a large open channel facility at the University of Minnesota’s St. Anthony Falls Laboratory (UMN-SAFL). Reference Model 1 (RM1) is a 1:40 geometric scale dual-rotor axial flow horizontal axis device with counter-rotating rotors, each with a rotor diameter dT = 0.5m. Precise blade angular position and torque measurements were synchronized with three acoustic Doppler velocimeters (ADVs) aligned with each rotor and the midpoint for RM1. Flow conditions for each case were controlled such that depth, h = 1m, and volumetric flow rate, Qw = 2.425m3s-1, resulting in a hub height velocity of approximately Uhub = 1.05ms-1 and blade chord length Reynolds numbers of Rec ≈ 3.0x105. Vertical velocity profiles collected in the wake of each device from 1 to 10 rotor diameters are used to estimate the velocity recovery and turbulent characteristics in the wake, as well as the interaction of the counter-rotating rotor wakes. The development of this high resolution laboratory investigation provides a robust dataset that enables assessing turbulence performance models and their ability to accurately predict device performance metrics, including computational fluid dynamics (CFD) models that can be used to predict turbulent inflow environments, reproduce wake velocity deficit, recovery and higher order turbulent statistics, as well as device performance metrics.

  8. Detection of a Bacteriophage Gene Encoding a Mu-like Portal Protein in Haemophilus parasuis Reference Strains and Field Isolates by Nested Polymerase Chain Reaction

    Science.gov (United States)

    A nested PCR assay was developed to determine the presence of a gene encoding a bacteriophage Mu-like portal protein, gp29, in 15 reference strains and 31 field isolates of Haemophilus parasuis. Specific primers, based on the gene’s sequence, were utilized. A majority of the virulent reference strai...

  9. Enabling full field physics based OPC via dynamic model generation

    Science.gov (United States)

    Lam, Michael; Clifford, Chris; Raghunathan, Ananthan; Fenger, Germain; Adam, Kostas

    2017-03-01

    As EUV lithography marches closer to reality for high volume production, its peculiar modeling challenges related to both inter- and intra- field effects has necessitated building OPC infrastructure that operates with field position dependency. Previous state of the art approaches to modeling field dependency used piecewise constant models where static input models are assigned to specific x/y-positions within the field. OPC and simulation could assign the proper static model based on simulation-level placement. However, in the realm of 7nm and 5nm feature sizes, small discontinuities in OPC from piecewise constant model changes can cause unacceptable levels of EPE errors. The introduction of Dynamic Model Generation (DMG) can be shown to effectively avoid these dislocations by providing unique mask and optical models per simulation region, allowing a near continuum of models through field. DMG allows unique models for EMF, apodization, aberrations, etc to vary through the entire field and provides a capability to precisely and accurately model systematic field signatures.

  10. Standard Reference Development of nuclear material for Tensile and Hardness Test Properties

    International Nuclear Information System (INIS)

    Choo, Y. S.; Kim, D. S.; Yoo, B. O.; Ahn, S. B.; Baik, S. J.; Chun, Y. B.; Kim, K. H.; Hong, K. P.; Ryu, W. S.

    2007-12-01

    Standard reference is a official approved data such a coefficient of physics, approved material properties, and etc., which should be analyzed and evaluated by scientific method to acquire official approval for accuracy and credibility of measured data and information. So it could be used broadly and continuously by various fields of nation and society. It is classified to effective standard reference, verified standard reference, and certified standard reference. There are sixteen fields in designated standard references such a physical chemistry field, material field, metal field, and the others. The standard reference of neutron irradiated nuclear structural material is classified to metal field. This report summarized the whole processes about data collection, data production, data evaluation and the suggestion of details evaluation technical standard for tensile and hardness properties, which were achieved by carry out the project 'nuclear material standard reference development' as a result

  11. Standard Reference Development of nuclear material for Tensile and Hardness Test Properties

    Energy Technology Data Exchange (ETDEWEB)

    Choo, Y. S.; Kim, D. S.; Yoo, B. O.; Ahn, S. B.; Baik, S. J.; Chun, Y. B.; Kim, K. H.; Hong, K. P.; Ryu, W. S

    2007-12-15

    Standard reference is a official approved data such a coefficient of physics, approved material properties, and etc., which should be analyzed and evaluated by scientific method to acquire official approval for accuracy and credibility of measured data and information. So it could be used broadly and continuously by various fields of nation and society. It is classified to effective standard reference, verified standard reference, and certified standard reference. There are sixteen fields in designated standard references such a physical chemistry field, material field, metal field, and the others. The standard reference of neutron irradiated nuclear structural material is classified to metal field. This report summarized the whole processes about data collection, data production, data evaluation and the suggestion of details evaluation technical standard for tensile and hardness properties, which were achieved by carry out the project 'nuclear material standard reference development' as a result.

  12. An Adaptive Critic Approach to Reference Model Adaptation

    Science.gov (United States)

    Krishnakumar, K.; Limes, G.; Gundy-Burlet, K.; Bryant, D.

    2003-01-01

    Neural networks have been successfully used for implementing control architectures for different applications. In this work, we examine a neural network augmented adaptive critic as a Level 2 intelligent controller for a C- 17 aircraft. This intelligent control architecture utilizes an adaptive critic to tune the parameters of a reference model, which is then used to define the angular rate command for a Level 1 intelligent controller. The present architecture is implemented on a high-fidelity non-linear model of a C-17 aircraft. The goal of this research is to improve the performance of the C-17 under degraded conditions such as control failures and battle damage. Pilot ratings using a motion based simulation facility are included in this paper. The benefits of using an adaptive critic are documented using time response comparisons for severe damage situations.

  13. Reference Models of Information Systems Constructed with the use of Technologies of Cloud Calculations

    Directory of Open Access Journals (Sweden)

    Darya Sergeevna Simonenkova

    2013-09-01

    Full Text Available The subject of the research is analysis of various models of the information system constructed with the use of technologies of cloud calculations. Analysis of models is required for constructing a new reference model which will be used for develop a security threats model.

  14. Modeling emotional dynamics : currency versus field.

    Energy Technology Data Exchange (ETDEWEB)

    Sallach, D .L.; Decision and Information Sciences; Univ. of Chicago

    2008-08-01

    Randall Collins has introduced a simplified model of emotional dynamics in which emotional energy, heightened and focused by interaction rituals, serves as a common denominator for social exchange: a generic form of currency, except that it is active in a far broader range of social transactions. While the scope of this theory is attractive, the specifics of the model remain unconvincing. After a critical assessment of the currency theory of emotion, a field model of emotion is introduced that adds expressiveness by locating emotional valence within its cognitive context, thereby creating an integrated orientation field. The result is a model which claims less in the way of motivational specificity, but is more satisfactory in modeling the dynamic interaction between cognitive and emotional orientations at both individual and social levels.

  15. Alien wavelength modeling tool and field trial

    DEFF Research Database (Denmark)

    Sambo, N.; Sgambelluri, A.; Secondini, M.

    2015-01-01

    A modeling tool is presented for pre-FEC BER estimation of PM-QPSK alien wavelength signals. A field trial is demonstrated and used as validation of the tool's correctness. A very close correspondence between the performance of the field trial and the one predicted by the modeling tool has been...

  16. Exotic nuclei in self-consistent mean-field models

    International Nuclear Information System (INIS)

    Bender, M.; Rutz, K.; Buervenich, T.; Reinhard, P.-G.; Maruhn, J. A.; Greiner, W.

    1999-01-01

    We discuss two widely used nuclear mean-field models, the relativistic mean-field model and the (nonrelativistic) Skyrme-Hartree-Fock model, and their capability to describe exotic nuclei with emphasis on neutron-rich tin isotopes and superheavy nuclei. (c) 1999 American Institute of Physics

  17. Roaming Reference: Reinvigorating Reference through Point of Need Service

    Directory of Open Access Journals (Sweden)

    Kealin M. McCabe

    2011-11-01

    Full Text Available Roaming reference service was pursued as a way to address declining reference statistics. The service was staffed by librarians armed with iPads over a period of six months during the 2010-2011 academic year. Transactional statistics were collected in relation to query type (Research, Facilitative or Technology, location and approach (librarian to patron, patron to librarian or via chat widget. Overall, roaming reference resulted in an additional 228 reference questions, 67% (n=153 of which were research related. Two iterations of the service were implemented, roaming reference as a standalone service (Fall 2010 and roaming reference integrated with traditional reference desk duties (Winter 2011. The results demonstrate that although the Weller Library’s reference transactions are declining annually, they are not disappearing. For a roaming reference service to succeed, it must be a standalone service provided in addition to traditional reference services. The integration of the two reference models (roaming reference and reference desk resulted in a 56% decline in the total number of roaming reference questions from the previous term. The simple act of roaming has the potential to reinvigorate reference services as a whole, forcing librarians outside their comfort zones, allowing them to reach patrons at their point of need.

  18. New parameterization of external and induced fields in geomagnetic field modeling, and a candidate model for IGRF 2005

    DEFF Research Database (Denmark)

    Olsen, Nils; Sabaka, T.J.; Lowes, F.

    2005-01-01

    When deriving spherical harmonic models of the Earth's magnetic field, low-degree external field contributions are traditionally considered by assuming that their expansion coefficient q(1)(0) varies linearly with the D-st-index, while induced contributions are considered assuming a constant ratio...... Q(1) of induced to external coefficients. A value of Q(1) = 0.27 was found from Magsat data and has been used by several authors when deriving recent field models from Orsted and CHAMP data. We describe a new approach that considers external and induced field based on a separation of D-st = E-st + I......-st into external (E-st) and induced (I-st) parts using a 1D model of mantle conductivity. The temporal behavior of q(1)(0) and of the corresponding induced coefficient are parameterized by E-st and I-st, respectively. In addition, we account for baseline-instabilities of D-st by estimating a value of q(1...

  19. Inertial reference frames and gravitational forces

    International Nuclear Information System (INIS)

    Santavy, I.

    1981-01-01

    The connection between different definitions of inertial, i.e. fundamental, reference frames and the corresponding characterisation of gravitational fields by gravitational forces are considered from the point of view of their possible interpretation in university introductory courses. The introduction of a special class of reference frames, denoted 'mixed reference frames' is proposed and discussed. (author)

  20. Special issue “International Geomagnetic Reference Field—the twelfth generation”

    OpenAIRE

    Thébault, E.; Finlay, C. C.; Toh, H.

    2015-01-01

    This special issue of Earth, Planets and Space, synthesizes the efforts made during the construction of the twelfth generation of the International Geomagnetic Reference Field (IGRF-12) that was released online in December 2014 (http://www.ngdc.noaa.gov/IAGA/vmod/ igrf.html). The IGRF-12 is a series of standard mathematical models describing the large scale internal part of the Earth’s magnetic field between epochs 1900.0 and 2015.0 with a forecast to epoch 2020.0. This activity has been main...

  1. Magnetic field decay in model SSC dipoles

    International Nuclear Information System (INIS)

    Gilbert, W.S.; Althaus, R.F.; Barale, P.J.; Benjegerdes, R.W.; Green, M.A.; Green, M.I.; Scanlan, R.M.

    1988-08-01

    We have observed that some of our model SSC dipoles have long time constant decays of the magnetic field harmonics with amplitudes large enough to result in significant beam loss, if they are not corrected. The magnets were run at constant current at the SSC injection field level of 0.3 tesla for one to three hours and changes in the magnetic field were observed. One explanation for the observed field decay is time dependent superconductor magnetization. Another explanation involves flux creep or flux flow. Data are presented on how the decay changes with previous flux history. Similar magnets with different Nb-Ti filament spacings and matrix materials have different long time field decay. A theoretical model using proximity coupling and flux creep for the observed field decay is discussed. 10 refs., 5 figs., 2 tabs

  2. Multi-media communication system: Upper layers in the OSI reference model

    NARCIS (Netherlands)

    Zafirovic-Vukotic, M.; Niemegeers, I.G.M.M.

    1992-01-01

    The structuring, services, and major protocol functions that are required in the upper layers of the OSI reference model in order to support end-to-end multimedia communication, assuming a simple transport service, are examined. It is assumed that variable-bit-rate (VBR) coding techniques will be

  3. Biomedical Engineering Desk Reference

    CERN Document Server

    Ratner, Buddy D; Schoen, Frederick J; Lemons, Jack E; Dyro, Joseph; Martinsen, Orjan G; Kyle, Richard; Preim, Bernhard; Bartz, Dirk; Grimnes, Sverre; Vallero, Daniel; Semmlow, John; Murray, W Bosseau; Perez, Reinaldo; Bankman, Isaac; Dunn, Stanley; Ikada, Yoshito; Moghe, Prabhas V; Constantinides, Alkis

    2009-01-01

    A one-stop Desk Reference, for Biomedical Engineers involved in the ever expanding and very fast moving area; this is a book that will not gather dust on the shelf. It brings together the essential professional reference content from leading international contributors in the biomedical engineering field. Material covers a broad range of topics including: Biomechanics and Biomaterials; Tissue Engineering; and Biosignal Processing* A hard-working desk reference providing all the essential material needed by biomedical and clinical engineers on a day-to-day basis * Fundamentals, key techniques,

  4. Multicomponent quantitative spectroscopic analysis without reference substances based on ICA modelling.

    Science.gov (United States)

    Monakhova, Yulia B; Mushtakova, Svetlana P

    2017-05-01

    A fast and reliable spectroscopic method for multicomponent quantitative analysis of targeted compounds with overlapping signals in complex mixtures has been established. The innovative analytical approach is based on the preliminary chemometric extraction of qualitative and quantitative information from UV-vis and IR spectral profiles of a calibration system using independent component analysis (ICA). Using this quantitative model and ICA resolution results of spectral profiling of "unknown" model mixtures, the absolute analyte concentrations in multicomponent mixtures and authentic samples were then calculated without reference solutions. Good recoveries generally between 95% and 105% were obtained. The method can be applied to any spectroscopic data that obey the Beer-Lambert-Bouguer law. The proposed method was tested on analysis of vitamins and caffeine in energy drinks and aromatic hydrocarbons in motor fuel with 10% error. The results demonstrated that the proposed method is a promising tool for rapid simultaneous multicomponent analysis in the case of spectral overlap and the absence/inaccessibility of reference materials.

  5. A corotation electric field model of the Earth derived from Swarm satellite magnetic field measurements

    Science.gov (United States)

    Maus, Stefan

    2017-08-01

    Rotation of the Earth in its own geomagnetic field sets up a primary corotation electric field, compensated by a secondary electric field of induced electrical charges. For the geomagnetic field measured by the Swarm constellation of satellites, a derivation of the global corotation electric field inside and outside of the corotation region is provided here, in both inertial and corotating reference frames. The Earth is assumed an electrical conductor, the lower atmosphere an insulator, followed by the corotating ionospheric E region again as a conductor. Outside of the Earth's core, the induced charge is immediately accessible from the spherical harmonic Gauss coefficients of the geomagnetic field. The charge density is positive at high northern and southern latitudes, negative at midlatitudes, and increases strongly toward the Earth's center. Small vertical electric fields of about 0.3 mV/m in the insulating atmospheric gap are caused by the corotation charges located in the ionosphere above and the Earth below. The corotation charges also flow outward into the region of closed magnetic field lines, forcing the plasmasphere to corotate. The electric field of the corotation charges further extends outside of the corotating regions, contributing radial outward electric fields of about 10 mV/m in the northern and southern polar caps. Depending on how the magnetosphere responds to these fields, the Earth may carry a net electric charge.

  6. Polyacetylene and relativistic field-theory models

    International Nuclear Information System (INIS)

    Bishop, A.R.; Campbell, D.K.; Fesser, K.

    1981-01-01

    Connections between continuum, mean-field, adiabatic Peierls-Froehlich theory in the half-filled band limit and known field theory results are discussed. Particular attention is given to the phi 4 model and to the solvable N = 2 Gross-Neveu model. The latter is equivalent to the Peierls system at a static, semi-classical level. Based on this equivalence we note the prediction of both kink and polaron solitons in models of trans-(CH)/sub x/. Polarons in cis-(CH)/sub x/ are compared with those in the trans isomer. Optical absorption from polarons is described, and general experimental consequences of polarons in (CH)/sub x/ and other conjugated polymers is discussed

  7. Self-consistent mean-field models for nuclear structure

    International Nuclear Information System (INIS)

    Bender, Michael; Heenen, Paul-Henri; Reinhard, Paul-Gerhard

    2003-01-01

    The authors review the present status of self-consistent mean-field (SCMF) models for describing nuclear structure and low-energy dynamics. These models are presented as effective energy-density functionals. The three most widely used variants of SCMF's based on a Skyrme energy functional, a Gogny force, and a relativistic mean-field Lagrangian are considered side by side. The crucial role of the treatment of pairing correlations is pointed out in each case. The authors discuss other related nuclear structure models and present several extensions beyond the mean-field model which are currently used. Phenomenological adjustment of the model parameters is discussed in detail. The performance quality of the SCMF model is demonstrated for a broad range of typical applications

  8. Model reference adaptive control (MRAC)-based parameter identification applied to surface-mounted permanent magnet synchronous motor

    Science.gov (United States)

    Zhong, Chongquan; Lin, Yaoyao

    2017-11-01

    In this work, a model reference adaptive control-based estimated algorithm is proposed for online multi-parameter identification of surface-mounted permanent magnet synchronous machines. By taking the dq-axis equations of a practical motor as the reference model and the dq-axis estimation equations as the adjustable model, a standard model-reference-adaptive-system-based estimator was established. Additionally, the Popov hyperstability principle was used in the design of the adaptive law to guarantee accurate convergence. In order to reduce the oscillation of identification result, this work introduces a first-order low-pass digital filter to improve precision regarding the parameter estimation. The proposed scheme was then applied to an SPM synchronous motor control system without any additional circuits and implemented using a DSP TMS320LF2812. For analysis, the experimental results reveal the effectiveness of the proposed method.

  9. On the electric field model for an open magnetosphere

    Science.gov (United States)

    Wang, Zhi; Ashour-Abdalla, Maha; Walker, Raymond J.

    1993-01-01

    We have developed a new canonical separator line type magnetospheric magnetic field and electric field model for use in magnetospheric calculations, we determine the magnetic and electric field by controlling the reconnection rate at the subsolar magnetopause. The model is applicable only for purely southward interplanetary magnetic field (IMF). We have obtained a more realistic magnetotail configuration by applying a stretch transformation to an axially symmetric field solution. We also discuss the Stern singularity in which there is an electric field singlarity in the canonical separate line models for B(sub y) not = to 0 by using a new technique that solves for the electric field along a field line directly instead of determining it by a potential mapping. The singularity not only causes an infinite electric field on the polar cap, but also causes the boundary conditions at plus infinity and minus infinity in the solar wind to contradict each other. This means that the canonical separator line models do not represent the open magnetosphere well, except for the case of purely southward IMF.

  10. Development of discrete choice model considering internal reference points and their effects in travel mode choice context

    Science.gov (United States)

    Sarif; Kurauchi, Shinya; Yoshii, Toshio

    2017-06-01

    In the conventional travel behavior models such as logit and probit, decision makers are assumed to conduct the absolute evaluations on the attributes of the choice alternatives. On the other hand, many researchers in cognitive psychology and marketing science have been suggesting that the perceptions of attributes are characterized by the benchmark called “reference points” and the relative evaluations based on them are often employed in various choice situations. Therefore, this study developed a travel behavior model based on the mental accounting theory in which the internal reference points are explicitly considered. A questionnaire survey about the shopping trip to the CBD in Matsuyama city was conducted, and then the roles of reference points in travel mode choice contexts were investigated. The result showed that the goodness-of-fit of the developed model was higher than that of the conventional model, indicating that the internal reference points might play the major roles in the choice of travel mode. Also shown was that the respondents seem to utilize various reference points: some tend to adopt the lowest fuel price they have experienced, others employ fare price they feel in perceptions of the travel cost.

  11. An Overview of the Most Important Reference Architectures for Cloud Computing

    Directory of Open Access Journals (Sweden)

    Razvan Daniel ZOTA

    2014-01-01

    Full Text Available In this paper we have presented the main characteristics of the most important reference archi-tectures designed for the cloud computing environment. Specifically, we have introduced the proposed architectures of the worldwide cloud computing companies like Cisco, IBM and VMware and we also had a look at the National Institute of Standards and Technology (NIST reference architecture which is the starting point for all proposed architectures in the field. As one would expect, the provider dependent reference architectures are written is such a way to suit the services and products of the company, while NIST’s architecture is a more general model with more comprehensive architectural details that we highlighted in this article. In the end of the article we draw out some conclusions regarding the existing reference architectures for cloud computing.

  12. A system for environmental protection. Reference dose models for fauna and flora

    International Nuclear Information System (INIS)

    Pentreath, R.J.; Woodhead, D.S.

    2000-01-01

    Ideas have already been published on how the current problems relating to environmental protection could be explicitly addressed. One of the basic cornerstones of the proposed system is that of the use of reference dose models for fauna and flora, in a manner analogous to those used for the human species. The concept is that, for a number of both aquatic and terrestrial fauna and flora types, 'reference' dose models, and dose per unit (internal and external) exposure tables, could be compiled. These would then be used to draw broad conclusions on the likely effects for such organisms in relation to three broad environment end points of concern: life shortening; impairment of reproductive capacity; and scorable, cytogenetic damage. The level of complexity of the dose models needs to be commensurate with the morphological complexity of the modelled organism, its size, and the data bases which are either available or could be reasonably obtained. The most basic models considered are either solid ellipsoids or spheres, with fixed dimensions. Secondary models contain internal, but relatively simple geometric features representative of those key organs or tissues for which more precise estimates of dose are required. Their level of complexity is also a function of different internal and external sources of radiation, and expected differences in radiosensitivities. Tertiary models -of greater complexity- are only considered to be of value for higher vertebrates. The potential derivation and use of all three sets of models is briefly discussed. (author)

  13. Common lines modeling for reference free Ab-initio reconstruction in cryo-EM.

    Science.gov (United States)

    Greenberg, Ido; Shkolnisky, Yoel

    2017-11-01

    We consider the problem of estimating an unbiased and reference-free ab initio model for non-symmetric molecules from images generated by single-particle cryo-electron microscopy. The proposed algorithm finds the globally optimal assignment of orientations that simultaneously respects all common lines between all images. The contribution of each common line to the estimated orientations is weighted according to a statistical model for common lines' detection errors. The key property of the proposed algorithm is that it finds the global optimum for the orientations given the common lines. In particular, any local optima in the common lines energy landscape do not affect the proposed algorithm. As a result, it is applicable to thousands of images at once, very robust to noise, completely reference free, and not biased towards any initial model. A byproduct of the algorithm is a set of measures that allow to asses the reliability of the obtained ab initio model. We demonstrate the algorithm using class averages from two experimental data sets, resulting in ab initio models with resolutions of 20Å or better, even from class averages consisting of as few as three raw images per class. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Impact of Relationships between Test and Reference Animals and between Reference Animals on Reliability of Genomic Prediction

    DEFF Research Database (Denmark)

    Wu, Xiaoping; Lund, Mogens Sandø; Sun, Dongxiao

    This study investigated reliability of genomic prediction in various scenarios with regard to relationship between test and reference animals and between animals within the reference population. Different reference populations were generated from EuroGenomics data and 1288 Nordic Holstein bulls...... as a common test population. A GBLUP model and a Bayesian mixture model were applied to predict Genomic breeding values for bulls in the test data. Result showed that a closer relationship between test and reference animals led to a higher reliability, while a closer relationship between reference animal...... resulted in a lower reliability. Therefore, the design of reference population is important for improving the reliability of genomic prediction. With regard to model, the Bayesian mixture model in general led to slightly a higher reliability of genomic prediction than the GBLUP model...

  15. Phase-field model of eutectic growth

    International Nuclear Information System (INIS)

    Karma, A.

    1994-01-01

    A phase-field model which describes the solidification of a binary eutectic alloy with a simple symmetric phase diagram is introduced and the sharp-interface limit of this model is explored both analytically and numerically

  16. Electromagnetic field for an open magnetosphere

    International Nuclear Information System (INIS)

    Heikkila, W.J.

    1984-01-01

    The boundary-layer-dominated models of the earth EM field developed by Heikkila (1975, 1978, 1982, and 1983) and Heikkila et al. (1979) to account for deficiencies in the electric-field descriptions of quasi-steady-state magnetic-field-reconnection models (such as that of Cowley, 1980) are characterized, reviewing the arguments and indicating the most important implications. The mechanisms of boundary-layer formation and field direction reversal are explained and illustrated with diagrams, and it is inferred that boundary-layer phenomena rather than magnetic reconnection may be the cause of large-scale magnetospheric circulation, convection, plasma-sheet formation and sunward convection, and auroras, the boundary layer acting basically as a viscous process mediating solar-wind/magnetosphere interactions. 23 references

  17. Gauge field models

    International Nuclear Information System (INIS)

    Becchi, C.; Rouet, A.; Stora, R.

    1975-10-01

    Stora's analysis is continued in discussing the nonabelian (Yang-Mills) gauge field models (G.F.M.). The gauge independence of the physical scattering operator is discussed in some details and the connection between its unitary and the Slavnov symmetry outlined. Only the models involving semisimple gauge groups are considered. This greatly simplifies the analysis of the possible quantum corrections to the Quantum Action Principle which is reduced to the study of the cohomology group of the Lie algebra characterizing the gauge theory. The discussion is at the classical level for the algebraic properties of the SU(2) Higgs-Kibble-Englert-Brout-Faddeev-Popov lagrangian and its invariance under Slavnov identity transformations is exhibited. The renormalization of the Slavnov identity in the G.M.F. involving semisimple gauge groups is studied. The unitary and gauge independence of the physical S operator in the SU(2) H.K. model is dealt with [fr

  18. A Nonlinear Dynamic Inversion Predictor-Based Model Reference Adaptive Controller for a Generic Transport Model

    Science.gov (United States)

    Campbell, Stefan F.; Kaneshige, John T.

    2010-01-01

    Presented here is a Predictor-Based Model Reference Adaptive Control (PMRAC) architecture for a generic transport aircraft. At its core, this architecture features a three-axis, non-linear, dynamic-inversion controller. Command inputs for this baseline controller are provided by pilot roll-rate, pitch-rate, and sideslip commands. This paper will first thoroughly present the baseline controller followed by a description of the PMRAC adaptive augmentation to this control system. Results are presented via a full-scale, nonlinear simulation of NASA s Generic Transport Model (GTM).

  19. Model of unified gauge fields; Le modele des champs de jauge unifies

    Energy Technology Data Exchange (ETDEWEB)

    Leite Lopes, J. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)

    1998-04-01

    In this work, we discuss the physical ideas which represents the basis for the unified gauge field model. Despite of the difficulties that we presently have for embodying in a natural manner muons and hadrons in that model, we have the feeling that we are on the way which seems to lead to the construction of a theory in which the Maxwell electromagnetic field and the Fermi weak interaction field are manifestations of a unique subjacent physical entity - the unified gauge fields. (author) 22 refs., 6 figs.

  20. A comparison between the example reference biosphere model ERB 2B and a process-based model: simulation of a natural release scenario.

    Science.gov (United States)

    Almahayni, T

    2014-12-01

    The BIOMASS methodology was developed with the objective of constructing defensible assessment biospheres for assessing potential radiological impacts of radioactive waste repositories. To this end, a set of Example Reference Biospheres were developed to demonstrate the use of the methodology and to provide an international point of reference. In this paper, the performance of the Example Reference Biosphere model ERB 2B associated with the natural release scenario, discharge of contaminated groundwater to the surface environment, was evaluated by comparing its long-term projections of radionuclide dynamics and distribution in a soil-plant system to those of a process-based, transient advection-dispersion model (AD). The models were parametrised with data characteristic of a typical rainfed winter wheat crop grown on a sandy loam soil under temperate climate conditions. Three safety-relevant radionuclides, (99)Tc, (129)I and (237)Np with different degree of sorption were selected for the study. Although the models were driven by the same hydraulic (soil moisture content and water fluxes) and radiological (Kds) input data, their projections were remarkably different. On one hand, both models were able to capture short and long-term variation in activity concentration in the subsoil compartment. On the other hand, the Reference Biosphere model did not project any radionuclide accumulation in the topsoil and crop compartments. This behaviour would underestimate the radiological exposure under natural release scenarios. The results highlight the potential role deep roots play in soil-to-plant transfer under a natural release scenario where radionuclides are released into the subsoil. When considering the relative activity and root depth profiles within the soil column, much of the radioactivity was taken up into the crop from the subsoil compartment. Further improvements were suggested to address the limitations of the Reference Biosphere model presented in this paper

  1. The iTREN-2030 reference scenario until 2030. Deliverable D4

    Energy Technology Data Exchange (ETDEWEB)

    Fiorello, Davide; De Stasio, Claudia; Koehler, Jonathan; Kraft, Markus; Netwon, Sean; Purwanto, Joko; Schade, Burkhard; Schade, Wolfgang; Szimba, Eckhard

    2009-07-01

    The basic objective of iTREN-2030 is to extend the forecasting and assessment capabilities of the TRANS-TOOLS transport model to the new policy issues arising from the technology, environment and energy fields. This is achieved by couplin the TRANS-TOOLS model with three other models, ASTRA, POLES and TREMOVE covering these new policy issues. The TRANS-TOOLS transport network model has been developed to constitute the reference tool for supporting transport policy in the EU and currently is being developed in several European projects. The scenario set-up to be developed in iTREN-2030 has been modified, so that the projects develops a reference scenario and an integrated scenario. For the reference scenario, the three other modelling tools are harmonised with TRANS-TOOLS and made consistent with each other. This results in a coherent scenario for Europe until 2030 for technology, transport, energy, environment and economic development. The integrated scenario will consider the changing framework conditions until 2030, inparticular the policy pressure coming from climate policy and the increasing scarcity of fossil fuels as well as the impact of the financial and economic crisis. Within the iTREN-2030 project, the overall objective of Work Package 4 (WP4) producing tis deliverable is to develop the reference scenario for the quantitative projections using the four modelling tools involved in the project. The main aims of WP4 are to (a) define a consistent framework for using the different tools in an integrated way; (b) calibrate models with exchanged input to a coherent joint reference; (c) implement external input from WP3 and running models for projections; (d) produce output procedures and templates to facilitate assessment in WP5.

  2. The Spallation Neutron Source RF Reference System

    CERN Document Server

    Piller, Maurice; Crofford, Mark; Doolittle, Lawrence; Ma, Hengjie

    2005-01-01

    The Spallation Neutron Source (SNS) RF Reference System includes the master oscillator (MO), local oscillator(LO) distribution, and Reference RF distribution systems. Coherent low noise Reference RF signals provide the ability to control the phase relationships between the fields in the front-end and linear accelerator (linac) RF cavity structures. The SNS RF Reference System requirements, implementation details, and performance are discussed.

  3. Wide-field schematic eye models with gradient-index lens.

    Science.gov (United States)

    Goncharov, Alexander V; Dainty, Chris

    2007-08-01

    We propose a wide-field schematic eye model, which provides a more realistic description of the optical system of the eye in relation to its anatomical structure. The wide-field model incorporates a gradient-index (GRIN) lens, which enables it to fulfill properties of two well-known schematic eye models, namely, Navarro's model for off-axis aberrations and Thibos's chromatic on-axis model (the Indiana eye). These two models are based on extensive experimental data, which makes the derived wide-field eye model also consistent with that data. A mathematical method to construct a GRIN lens with its iso-indicial contours following the optical surfaces of given asphericity is presented. The efficiency of the method is demonstrated with three variants related to different age groups. The role of the GRIN structure in relation to the lens paradox is analyzed. The wide-field model with a GRIN lens can be used as a starting design for the eye inverse problem, i.e., reconstructing the optical structure of the eye from off-axis wavefront measurements. Anatomically more accurate age-dependent optical models of the eye could ultimately help an optical designer to improve wide-field retinal imaging.

  4. Land-use history and contemporary management inform an ecological reference model for longleaf pine woodland understory plant communities

    Science.gov (United States)

    Lars A. Brudvig; John L. Orrock; Ellen I. Damschen; Cathy D. Collins; Philip G. Hahn; W. Brett Mattingly; Joseph W. Veldman; Joan L. Walker

    2014-01-01

    Ecological restoration is frequently guided by reference conditions describing a successfully restored ecosystem; however, the causes and magnitude of ecosystem degradation vary, making simple knowledge of reference conditions insufficient for prioritizing and guiding restoration. Ecological reference models provide further guidance by quantifying reference conditions...

  5. Reversed-Field Pinch plasma model

    International Nuclear Information System (INIS)

    Miley, G.H.; Nebel, R.A.; Moses, R.W.

    1979-01-01

    The stability of a Reversed-Field Pinch (RFP) is strongly dependent on the plasma profile and the confining sheared magnetic field. Magnetic diffusion and thermal transport produce changing conditions of stability. Despite the limited understanding of RFP transport, modelling is important to predict general trends and to study possible field programming options. To study the ZT-40 experiment and to predict the performance of future RFP reactors, a one-dimensional transport code has been developed. This code includes a linear, ideal MHD stability check based on an energy principle. The transport section integrates plasma profiles forward in time while the stability section periodically checks the stability of the evolving plasma profile

  6. Development of the Japanese reference man model for age-specific phantoms

    International Nuclear Information System (INIS)

    Kawamura, H.

    2012-01-01

    Recent interest in improving methods for calculating radiation doses to atomic bomb survivors necessitates reinforcing the data on masses of organs of the Japanese population in 1945, including those that are not calculated by DS02, as well as increasing the number of phantoms for different ages. Reference is made to published data on the masses of organs in normal Japanese subjects of 0-90 y of age with more than 5000 samples during 1970-80, as well as the weight and size of the total body. The first Japanese Reference Man model, primarily based on these data and following the ICRP Reference Man concept, is briefly explained. It provides a set of reference values for males and females of six age groups, i.e. 3 months, 1, 5, 10, 15 and 20-50 y. To consider the organ masses of the Japanese population in 1945, the data during the period 1970-80 are compared with the literature data of normal Japanese reported in 1952. Differences between the two sets of organ data in adults are discussed in relation to changes in the national status of nutrition. Additional organ masses of current interest for the Japanese population in 1945 are preliminarily considered. (author)

  7. Neutron Reference Benchmark Field Specification: ACRR 44 Inch Lead-Boron (LB44) Bucket Environment (ACRR-LB44-CC-32-CL).

    Energy Technology Data Exchange (ETDEWEB)

    Vega, Richard Manuel [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Parma, Edward J. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Griffin, Patrick J. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Vehar, David W. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    2015-07-01

    This report was put together to support the International Atomic Energy Agency (IAEA) REAL- 2016 activity to validate the dosimetry community’s ability to use a consistent set of activation data and to derive consistent spectral characterizations. The report captures details of integral measurements taken in the Annular Core Research Reactor (ACRR) central cavity with the 44 inch Lead-Boron (LB44) bucket, reference neutron benchmark field. The field is described and an “a priori” calculated neutron spectrum is reported, based on MCNP6 calculations, and a subject matter expert (SME) based covariance matrix is given for this “a priori” spectrum. The results of 31 integral dosimetry measurements in the neutron field are reported.

  8. The Research of the Driver Attention Field Modeling

    Directory of Open Access Journals (Sweden)

    Pengfei Tao

    2014-01-01

    Full Text Available For expanding the application scope of car-following, based on the basic idea of the noncontact interaction of the objects in physics, establish an attention field model to describe the driving behavior. Firstly, propose the time distance concept to describe the degree of driver perception to the front one-dimensional space and extend its application range to the two-dimensional space. Secondly, connect the point which has the same time distance to constitute the equipotential line of drivers’ attention field equipotent, and establish a model to describe it. Thirdly, define the effective range of the driver’s psychological field with the feature of the driver’s visual distance range increasing and the angle decreasing. Finally, design the calculation method to collect projection of the object in the psychological field scope and calculate the curve points to determine the object’s intensity of psychological field. Preliminarily build the driving behavior model and use the numerical simulation method to simulate the simple transport scenarios; initially verify the validity of the model.

  9. Correlation Models for Temperature Fields

    KAUST Repository

    North, Gerald R.

    2011-05-16

    This paper presents derivations of some analytical forms for spatial correlations of evolving random fields governed by a white-noise-driven damped diffusion equation that is the analog of autoregressive order 1 in time and autoregressive order 2 in space. The study considers the two-dimensional plane and the surface of a sphere, both of which have been studied before, but here time is introduced to the problem. Such models have a finite characteristic length (roughly the separation at which the autocorrelation falls to 1/e) and a relaxation time scale. In particular, the characteristic length of a particular temporal Fourier component of the field increases to a finite value as the frequency of the particular component decreases. Some near-analytical formulas are provided for the results. A potential application is to the correlation structure of surface temperature fields and to the estimation of large area averages, depending on how the original datastream is filtered into a distribution of Fourier frequencies (e.g., moving average, low pass, or narrow band). The form of the governing equation is just that of the simple energy balance climate models, which have a long history in climate studies. The physical motivation provided by the derivation from a climate model provides some heuristic appeal to the approach and suggests extensions of the work to nonuniform cases.

  10. Correlation Models for Temperature Fields

    KAUST Repository

    North, Gerald R.; Wang, Jue; Genton, Marc G.

    2011-01-01

    This paper presents derivations of some analytical forms for spatial correlations of evolving random fields governed by a white-noise-driven damped diffusion equation that is the analog of autoregressive order 1 in time and autoregressive order 2 in space. The study considers the two-dimensional plane and the surface of a sphere, both of which have been studied before, but here time is introduced to the problem. Such models have a finite characteristic length (roughly the separation at which the autocorrelation falls to 1/e) and a relaxation time scale. In particular, the characteristic length of a particular temporal Fourier component of the field increases to a finite value as the frequency of the particular component decreases. Some near-analytical formulas are provided for the results. A potential application is to the correlation structure of surface temperature fields and to the estimation of large area averages, depending on how the original datastream is filtered into a distribution of Fourier frequencies (e.g., moving average, low pass, or narrow band). The form of the governing equation is just that of the simple energy balance climate models, which have a long history in climate studies. The physical motivation provided by the derivation from a climate model provides some heuristic appeal to the approach and suggests extensions of the work to nonuniform cases.

  11. SU-E-T-242: Monte Carlo Simulations Used to Test the Perturbation of a Reference Ion Chamber Prototype Used for Small Fields

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez Quino, L; Calvo, O; Huerta, C; DeWeese, M [Midsouth Radation Physics, Little Rock, AR (United States)

    2014-06-01

    Purpose: To study the perturbation due to the use of a novel Reference Ion Chamber designed to measure small field dosimetry (KermaX Plus C by IBA). Methods: Using the Phase-space files for TrueBeam photon beams available by Varian in IAEA-compliant format for 6 and 15 MV. Monte Carlo simulations were performed using BEAMnrc and DOSXYZnrc to investigate the perturbation introduced by a reference chamber into the PDDs and profiles measured in water tank. Field sizes ranging from 1×1, 2×2,3×3, 5×5 cm2 were simulated for both energies with and without a 0.5 mm foil of Aluminum which is equivalent to the attenuation equivalent of the reference chamber specifications in a water phantom of 30×30×30 cm3 and a pixel resolution of 2 mm. The PDDs, profiles, and gamma analysis of the simulations were performed as well as a energy spectrum analysis of the phase-space files generated during the simulation. Results: Examination of the energy spectrum analysis performed shown a very small increment of the energy spectrum at the build-up region but no difference is appreciated after dmax. The PDD, profiles and gamma analysis had shown a very good agreement among the simulations with and without the Al foil, with a gamma analysis with a criterion of 2% and 2mm resulting in 99.9% of the points passing this criterion. Conclusion: This work indicates the potential benefits of using the KermaX Plus C as reference chamber in the measurement of PDD and Profiles for small fields since the perturbation due to in the presence of the chamber the perturbation is minimal and the chamber can be considered transparent to the photon beam.

  12. Modeling the Global Coronal Field with Simulated Synoptic Magnetograms from Earth and the Lagrange Points L3, L4, and L5

    Science.gov (United States)

    Petrie, Gordon; Pevtsov, Alexei; Schwarz, Andrew; DeRosa, Marc

    2018-06-01

    The solar photospheric magnetic flux distribution is key to structuring the global solar corona and heliosphere. Regular full-disk photospheric magnetogram data are therefore essential to our ability to model and forecast heliospheric phenomena such as space weather. However, our spatio-temporal coverage of the photospheric field is currently limited by our single vantage point at/near Earth. In particular, the polar fields play a leading role in structuring the large-scale corona and heliosphere, but each pole is unobservable for {>} 6 months per year. Here we model the possible effect of full-disk magnetogram data from the Lagrange points L4 and L5, each extending longitude coverage by 60°. Adding data also from the more distant point L3 extends the longitudinal coverage much further. The additional vantage points also improve the visibility of the globally influential polar fields. Using a flux-transport model for the solar photospheric field, we model full-disk observations from Earth/L1, L3, L4, and L5 over a solar cycle, construct synoptic maps using a novel weighting scheme adapted for merging magnetogram data from multiple viewpoints, and compute potential-field models for the global coronal field. Each additional viewpoint brings the maps and models into closer agreement with the reference field from the flux-transport simulation, with particular improvement at polar latitudes, the main source of the fast solar wind.

  13. Probabilistic calculations and sensitivity analysis of parameters for a reference biosphere model assessing the potential exposure of a population to radionuclides from a deep geological repository

    Energy Technology Data Exchange (ETDEWEB)

    Staudt, Christian; Kaiser, Jan Christian [Helmholtz Zentrum Muenchen, Institute of Radiation Protection, Munich (Germany); Proehl, Gerhard [International Atomic Energy Agency, Division of Radiation, Transport and Waste Safety, Wagramerstrasse 5, 1400 Vienna (Austria)

    2014-07-01

    Radioecological models are used to assess the exposure of hypothetical populations to radionuclides. Potential radionuclide sources are deep geological repositories for high level radioactive waste. Assessment time frames are long since releases from those repositories are only expected in the far future, and radionuclide migration to the geosphere biosphere interface will take additional time. Due to the long time frames, climate conditions at the repository site will change, leading to changing exposure pathways and model parameters. To identify climate dependent changes in exposure in the far field of a deep geological repository a range of reference biosphere models representing climate analogues for potential future climate states at a German site were developed. In this approach, model scenarios are developed for different contemporary climate states. It is assumed that the exposure pathways and parameters of the contemporary biosphere in the far field of the repository will change to be similar to those at the analogue sites. Since current climate models cannot predict climate developments over the assessment time frame of 1 million years, analogues for a range of realistically possible future climate conditions were selected. These climate states range from steppe to permafrost climate. As model endpoint Biosphere Dose conversion factors (BDCF) are calculated. The radionuclide specific BDCF describe the exposure of a population to radionuclides entering the biosphere in near surface ground water. The BDCF are subject to uncertainties in the exposure pathways and model parameters. In the presented work, probabilistic and sensitivity analysis was used to assess the influence of model parameter uncertainties on the BDCF and the relevance of individual parameters for the model result. This was done for the long half-live radionuclides Cs-135, I-129 and U-238. In addition to this, BDCF distributions for nine climate reference regions and several scenarios were

  14. Microarray-based comparative genomic profiling of reference strains and selected Canadian field isolates of Actinobacillus pleuropneumoniae

    Directory of Open Access Journals (Sweden)

    MacInnes Janet I

    2009-02-01

    Full Text Available Abstract Background Actinobacillus pleuropneumoniae, the causative agent of porcine pleuropneumonia, is a highly contagious respiratory pathogen that causes severe losses to the swine industry worldwide. Current commercially-available vaccines are of limited value because they do not induce cross-serovar immunity and do not prevent development of the carrier state. Microarray-based comparative genomic hybridizations (M-CGH were used to estimate whole genomic diversity of representative Actinobacillus pleuropneumoniae strains. Our goal was to identify conserved genes, especially those predicted to encode outer membrane proteins and lipoproteins because of their potential for the development of more effective vaccines. Results Using hierarchical clustering, our M-CGH results showed that the majority of the genes in the genome of the serovar 5 A. pleuropneumoniae L20 strain were conserved in the reference strains of all 15 serovars and in representative field isolates. Fifty-eight conserved genes predicted to encode for outer membrane proteins or lipoproteins were identified. As well, there were several clusters of diverged or absent genes including those associated with capsule biosynthesis, toxin production as well as genes typically associated with mobile elements. Conclusion Although A. pleuropneumoniae strains are essentially clonal, M-CGH analysis of the reference strains of the fifteen serovars and representative field isolates revealed several classes of genes that were divergent or absent. Not surprisingly, these included genes associated with capsule biosynthesis as the capsule is associated with sero-specificity. Several of the conserved genes were identified as candidates for vaccine development, and we conclude that M-CGH is a valuable tool for reverse vaccinology.

  15. CD-SEM real time bias correction using reference metrology based modeling

    Science.gov (United States)

    Ukraintsev, V.; Banke, W.; Zagorodnev, G.; Archie, C.; Rana, N.; Pavlovsky, V.; Smirnov, V.; Briginas, I.; Katnani, A.; Vaid, A.

    2018-03-01

    Accuracy of patterning impacts yield, IC performance and technology time to market. Accuracy of patterning relies on optical proximity correction (OPC) models built using CD-SEM inputs and intra die critical dimension (CD) control based on CD-SEM. Sub-nanometer measurement uncertainty (MU) of CD-SEM is required for current technologies. Reported design and process related bias variation of CD-SEM is in the range of several nanometers. Reference metrology and numerical modeling are used to correct SEM. Both methods are slow to be used for real time bias correction. We report on real time CD-SEM bias correction using empirical models based on reference metrology (RM) data. Significant amount of currently untapped information (sidewall angle, corner rounding, etc.) is obtainable from SEM waveforms. Using additional RM information provided for specific technology (design rules, materials, processes) CD extraction algorithms can be pre-built and then used in real time for accurate CD extraction from regular CD-SEM images. The art and challenge of SEM modeling is in finding robust correlation between SEM waveform features and bias of CD-SEM as well as in minimizing RM inputs needed to create accurate (within the design and process space) model. The new approach was applied to improve CD-SEM accuracy of 45 nm GATE and 32 nm MET1 OPC 1D models. In both cases MU of the state of the art CD-SEM has been improved by 3x and reduced to a nanometer level. Similar approach can be applied to 2D (end of line, contours, etc.) and 3D (sidewall angle, corner rounding, etc.) cases.

  16. Organizational Learning Supported by Reference Architecture Models

    DEFF Research Database (Denmark)

    Nardello, Marco; Møller, Charles; Gøtze, John

    2017-01-01

    The wave of the fourth industrial revolution (Industry 4.0) is bringing a new vision of the manufacturing industry. In manufacturing, one of the buzzwords of the moment is “Smart production”. Smart production involves manufacturing equipment with many sensors that can generate and transmit large...... amounts of data. These data and information from manufacturing operations are however not shared in the organization. Therefore the organization is not using them to learn and improve their operations. To address this problem, the authors implemented in an Industry 4.0 laboratory an instance...... of an emerging technical standard specific for the manufacturing industry. Global manufacturing experts consider the Reference Architecture Model Industry 4.0 (RAMI4.0) as one of the corner stones for the implementation of Industry 4.0. The instantiation contributed to organizational learning in the laboratory...

  17. Multi-relaxation-time lattice Boltzmann modeling of the acoustic field generated by focused transducer

    Science.gov (United States)

    Shan, Feng; Guo, Xiasheng; Tu, Juan; Cheng, Jianchun; Zhang, Dong

    The high-intensity focused ultrasound (HIFU) has become an attractive therapeutic tool for the noninvasive tumor treatment. The ultrasonic transducer is the key component in HIFU treatment to generate the HIFU energy. The dimension of focal region generated by the transducer is closely relevant to the safety of HIFU treatment. Therefore, it is essential to numerically investigate the focal region of the transducer. Although the conventional acoustic wave equations have been used successfully to describe the acoustic field, there still exist some inherent drawbacks. In this work, we presented an axisymmetric isothermal multi-relaxation-time lattice Boltzmann method (MRT-LBM) model with the Bouzidi-Firdaouss-Lallemand (BFL) boundary condition in cylindrical coordinate system. With this model, some preliminary simulations were firstly conducted to determine a reasonable value of the relaxation parameter. Then, the validity of the model was examined by comparing the results obtained with the LBM results with the Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation and the Spheroidal beam equation (SBE) for the focused transducers with different aperture angles, respectively. In addition, the influences of the aperture angle on the focal region were investigated. The proposed model in this work will provide significant references for the parameter optimization of the focused transducer for applications in the HIFU treatment or other fields, and provide new insights into the conventional acoustic numerical simulations.

  18. Grimsel Test Site: modelling radionuclide migration field experiments

    International Nuclear Information System (INIS)

    Heer, W.; Hadermann, J.

    1994-09-01

    In the migration field experiments at Nagra's Grimsel Test Site, the processes of nuclide transport through a well defined fractured shear-zone in crystalline rock are being investigated. For these experiments, model calculations have been performed to obtain indications on validity and limitation of the model applied and the data deduced under field conditions. The model consists of a hydrological part, where the dipole flow fields of the experiments are determined, and a nuclide transport part, where the flow field driven nuclide propagation through the shear-zone is calculated. In addition to the description of the model, analytical expressions are given to guide the interpretation of experimental results. From the analysis of experimental breakthrough curves for conservative uranine, weakly sorbing sodium and more stronger sorbing strontium tracers, the following main results can be derived: i) The model is able to represent the breakthrough curves of the migration field experiments to a high degree of accuracy, ii) The process of matrix diffusion is manifest through the tails of the breakthrough curves decreasing with time as t -3/2 and through the special shape of the tail ends, both confirmed by the experiments, iii) For nuclide sorbing rapidly, not too strongly, linearly, and exhibiting a reversible cation exchange process on fault gouge, the laboratory sorption coefficient can reasonably well be extrapolated to field conditions. Adequate care in selecting and preparing the rock samples is, of course, a necessary requirement. Using the parameters determined in the previous analysis, predictions are made for experiments in a smaller an faster flow field. For conservative uranine and weakly sorbing sodium, the agreement of predicted and measured breakthrough curves is good, for the more stronger sorbing strontium reasonable, confirming that the model describes the main nuclide transport processes adequately. (author) figs., tabs., 29 refs

  19. Second-order sliding mode controller with model reference adaptation for automatic train operation

    Science.gov (United States)

    Ganesan, M.; Ezhilarasi, D.; Benni, Jijo

    2017-11-01

    In this paper, a new approach to model reference based adaptive second-order sliding mode control together with adaptive state feedback is presented to control the longitudinal dynamic motion of a high speed train for automatic train operation with the objective of minimal jerk travel by the passengers. The nonlinear dynamic model for the longitudinal motion of the train comprises of a locomotive and coach subsystems is constructed using multiple point-mass model by considering the forces acting on the vehicle. An adaptation scheme using Lyapunov criterion is derived to tune the controller gains by considering a linear, stable reference model that ensures the stability of the system in closed loop. The effectiveness of the controller tracking performance is tested under uncertain passenger load, coupler-draft gear parameters, propulsion resistance coefficients variations and environmental disturbances due to side wind and wet rail conditions. The results demonstrate improved tracking performance of the proposed control scheme with a least jerk under maximum parameter uncertainties when compared to constant gain second-order sliding mode control.

  20. Mean-field models and superheavy elements

    International Nuclear Information System (INIS)

    Reinhard, P.G.; Bender, M.; Maruhn, J.A.; Frankfurt Univ.

    2001-03-01

    We discuss the performance of two widely used nuclear mean-field models, the relativistic mean-field theory (RMF) and the non-relativistic Skyrme-Hartree-Fock approach (SHF), with particular emphasis on the description of superheavy elements (SHE). We provide a short introduction to the SHF and RMF, the relations between these two approaches and the relations to other nuclear structure models, briefly review the basic properties with respect to normal nuclear observables, and finally present and discuss recent results on the binding properties of SHE computed with a broad selection of SHF and RMF parametrisations. (orig.)

  1. Covariant field equations, gauge fields and conservation laws from Yang-Mills matrix models

    International Nuclear Information System (INIS)

    Steinacker, Harold

    2009-01-01

    The effective geometry and the gravitational coupling of nonabelian gauge and scalar fields on generic NC branes in Yang-Mills matrix models is determined. Covariant field equations are derived from the basic matrix equations of motions, known as Yang-Mills algebra. Remarkably, the equations of motion for the Poisson structure and for the nonabelian gauge fields follow from a matrix Noether theorem, and are therefore protected from quantum corrections. This provides a transparent derivation and generalization of the effective action governing the SU(n) gauge fields obtained in [1], including the would-be topological term. In particular, the IKKT matrix model is capable of describing 4-dimensional NC space-times with a general effective metric. Metric deformations of flat Moyal-Weyl space are briefly discussed.

  2. The Uhlenbeck-Ford model: Exact virial coefficients and application as a reference system in fluid-phase free-energy calculations

    Science.gov (United States)

    Paula Leite, Rodolfo; Freitas, Rodrigo; Azevedo, Rodolfo; de Koning, Maurice

    2016-11-01

    The Uhlenbeck-Ford (UF) model was originally proposed for the theoretical study of imperfect gases, given that all its virial coefficients can be evaluated exactly, in principle. Here, in addition to computing the previously unknown coefficients B11 through B13, we assess its applicability as a reference system in fluid-phase free-energy calculations using molecular simulation techniques. Our results demonstrate that, although the UF model itself is too soft, appropriately scaled Uhlenbeck-Ford (sUF) models provide robust reference systems that allow accurate fluid-phase free-energy calculations without the need for an intermediate reference model. Indeed, in addition to the accuracy with which their free energies are known and their convenient scaling properties, the fluid is the only thermodynamically stable phase for a wide range of sUF models. This set of favorable properties may potentially put the sUF fluid-phase reference systems on par with the standard role that harmonic and Einstein solids play as reference systems for solid-phase free-energy calculations.

  3. Full field reservoir modeling of shale assets using advanced data-driven analytics

    Directory of Open Access Journals (Sweden)

    Soodabeh Esmaili

    2016-01-01

    Full Text Available Hydrocarbon production from shale has attracted much attention in the recent years. When applied to this prolific and hydrocarbon rich resource plays, our understanding of the complexities of the flow mechanism (sorption process and flow behavior in complex fracture systems - induced or natural leaves much to be desired. In this paper, we present and discuss a novel approach to modeling, history matching of hydrocarbon production from a Marcellus shale asset in southwestern Pennsylvania using advanced data mining, pattern recognition and machine learning technologies. In this new approach instead of imposing our understanding of the flow mechanism, the impact of multi-stage hydraulic fractures, and the production process on the reservoir model, we allow the production history, well log, completion and hydraulic fracturing data to guide our model and determine its behavior. The uniqueness of this technology is that it incorporates the so-called “hard data” directly into the reservoir model, so that the model can be used to optimize the hydraulic fracture process. The “hard data” refers to field measurements during the hydraulic fracturing process such as fluid and proppant type and amount, injection pressure and rate as well as proppant concentration. This novel approach contrasts with the current industry focus on the use of “soft data” (non-measured, interpretive data such as frac length, width, height and conductivity in the reservoir models. The study focuses on a Marcellus shale asset that includes 135 wells with multiple pads, different landing targets, well length and reservoir properties. The full field history matching process was successfully completed using this data driven approach thus capturing the production behavior with acceptable accuracy for individual wells and for the entire asset.

  4. Technical Work Plan for: Near Field Environment: Engineered System: Radionuclide Transport Abstraction Model Report

    Energy Technology Data Exchange (ETDEWEB)

    J.D. Schreiber

    2006-12-08

    This technical work plan (TWP) describes work activities to be performed by the Near-Field Environment Team. The objective of the work scope covered by this TWP is to generate Revision 03 of EBS Radionuclide Transport Abstraction, referred to herein as the radionuclide transport abstraction (RTA) report. The RTA report is being revised primarily to address condition reports (CRs), to address issues identified by the Independent Validation Review Team (IVRT), to address the potential impact of transport, aging, and disposal (TAD) canister design on transport models, and to ensure integration with other models that are closely associated with the RTA report and being developed or revised in other analysis/model reports in response to IVRT comments. The RTA report will be developed in accordance with the most current version of LP-SIII.10Q-BSC and will reflect current administrative procedures (LP-3.15Q-BSC, ''Managing Technical Product Inputs''; LP-SIII.2Q-BSC, ''Qualification of Unqualified Data''; etc.), and will develop related Document Input Reference System (DIRS) reports and data qualifications as applicable in accordance with prevailing procedures. The RTA report consists of three models: the engineered barrier system (EBS) flow model, the EBS transport model, and the EBS-unsaturated zone (UZ) interface model. The flux-splitting submodel in the EBS flow model will change, so the EBS flow model will be validated again. The EBS transport model and validation of the model will be substantially revised in Revision 03 of the RTA report, which is the main subject of this TWP. The EBS-UZ interface model may be changed in Revision 03 of the RTA report due to changes in the conceptualization of the UZ transport abstraction model (a particle tracker transport model based on the discrete fracture transfer function will be used instead of the dual-continuum transport model previously used). Validation of the EBS-UZ interface model

  5. Effective field theory and the quark model

    International Nuclear Information System (INIS)

    Durand, Loyal; Ha, Phuoc; Jaczko, Gregory

    2001-01-01

    We analyze the connections between the quark model (QM) and the description of hadrons in the low-momentum limit of heavy-baryon effective field theory in QCD. By using a three-flavor-index representation for the effective baryon fields, we show that the 'nonrelativistic' constituent QM for baryon masses and moments is completely equivalent through O(m s ) to a parametrization of the relativistic field theory in a general spin-flavor basis. The flavor and spin variables can be identified with those of effective valence quarks. Conversely, the spin-flavor description clarifies the structure and dynamical interpretation of the chiral expansion in effective field theory, and provides a direct connection between the field theory and the semirelativistic models for hadrons used in successful dynamical calculations. This allows dynamical information to be incorporated directly into the chiral expansion. We find, for example, that the striking success of the additive QM for baryon magnetic moments is a consequence of the relative smallness of the non-additive spin-dependent corrections

  6. Computation of a Reference Model for Robust Fault Detection and Isolation Residual Generation

    Directory of Open Access Journals (Sweden)

    Emmanuel Mazars

    2008-01-01

    Full Text Available This paper considers matrix inequality procedures to address the robust fault detection and isolation (FDI problem for linear time-invariant systems subject to disturbances, faults, and polytopic or norm-bounded uncertainties. We propose a design procedure for an FDI filter that aims to minimize a weighted combination of the sensitivity of the residual signal to disturbances and modeling errors, and the deviation of the faults to residual dynamics from a fault to residual reference model, using the ℋ∞-norm as a measure. A key step in our procedure is the design of an optimal fault reference model. We show that the optimal design requires the solution of a quadratic matrix inequality (QMI optimization problem. Since the solution of the optimal problem is intractable, we propose a linearization technique to derive a numerically tractable suboptimal design procedure that requires the solution of a linear matrix inequality (LMI optimization. A jet engine example is employed to demonstrate the effectiveness of the proposed approach.

  7. Quantum field model of strong-coupling binucleon

    International Nuclear Information System (INIS)

    Amirkhanov, I.V.; Puzynin, I.V.; Puzynina, T.P.; Strizh, T.A.; Zemlyanaya, E.V.; Lakhno, V.D.

    1996-01-01

    The quantum field binucleon model for the case of the nucleon spot interaction with the scalar and pseudoscalar meson fields is considered. It is shown that the nonrelativistic problem of the two nucleon interaction reduces to the one-particle problem. For the strong coupling limit the nonlinear equations describing two nucleons in the meson field are developed [ru

  8. Measurements of H*(10) in reference neutron fields using Bonner sphere spectrometry and LET spectrometry

    CERN Document Server

    Golnik, N; Králik, M

    2002-01-01

    A Bonner sphere spectrometer and the REM-2 recombination chamber were used for inter-comparison measurements of the neutron component of ambient dose equivalent, H sub n *(10) in reference neutron fields. The sup 2 sup 4 sup 1 Am-Be and sup 2 sup 5 sup 2 Cf neutron sources were exposed either free-in-air or placed in iron or paraffin filters. The REM-2 recombination chamber was used as a LET spectrometer. The agreement of H sub n *(10) values measured with both the methods was within experimental uncertainties of few percent. The determined neutron spectra were used for calculations of the REM-2 chamber response to H*(10).

  9. Matrix models as non-commutative field theories on R3

    International Nuclear Information System (INIS)

    Livine, Etera R

    2009-01-01

    In the context of spin foam models for quantum gravity, group field theories are a useful tool allowing on the one hand a non-perturbative formulation of the partition function and on the other hand admitting an interpretation as generalized matrix models. Focusing on 2d group field theories, we review their explicit relation to matrix models and show their link to a class of non-commutative field theories invariant under a quantum-deformed 3d Poincare symmetry. This provides a simple relation between matrix models and non-commutative geometry. Moreover, we review the derivation of effective 2d group field theories with non-trivial propagators from Boulatov's group field theory for 3d quantum gravity. Besides the fact that this gives a simple and direct derivation of non-commutative field theories for the matter dynamics coupled to (3d) quantum gravity, these effective field theories can be expressed as multi-matrix models with a non-trivial coupling between matrices of different sizes. It should be interesting to analyze this new class of theories, both from the point of view of matrix models as integrable systems and for the study of non-commutative field theories.

  10. Defining Leadership as Process Reference Model: Translating Organizational Goals into Practice Using a Structured Leadership Approach

    OpenAIRE

    Tuffley , David

    2010-01-01

    International audience; Effective leadership in organisations is important to the achievement of organizational objectives. Yet leadership is widely seen as a quality that individuals innately possess, and which cannot be learned. This paper makes two assertions; (a) that leadership is a skill that not only can be learned, but which can be formalized into a Process Reference Model that is intelligible from an Enterprise Architecture perspective, and (b) that Process Reference Models in the st...

  11. Effect of external fields in Axelrod's model of social dynamics

    Science.gov (United States)

    Peres, Lucas R.; Fontanari, José F.

    2012-09-01

    The study of the effects of spatially uniform fields on the steady-state properties of Axelrod's model has yielded plenty of counterintuitive results. Here, we reexamine the impact of this type of field for a selection of parameters such that the field-free steady state of the model is heterogeneous or multicultural. Analyses of both one- and two-dimensional versions of Axelrod's model indicate that the steady state remains heterogeneous regardless of the value of the field strength. Turning on the field leads to a discontinuous decrease on the number of cultural domains, which we argue is due to the instability of zero-field heterogeneous absorbing configurations. We find, however, that spatially nonuniform fields that implement a consensus rule among the neighborhood of the agents enforce homogenization. Although the overall effects of the fields are essentially the same irrespective of the dimensionality of the model, we argue that the dimensionality has a significant impact on the stability of the field-free homogeneous steady state.

  12. A Comprehensive Model of the Near-Earth Magnetic Field. Phase 3

    Science.gov (United States)

    Sabaka, Terence J.; Olsen, Nils; Langel, Robert A.

    2000-01-01

    The near-Earth magnetic field is due to sources in Earth's core, ionosphere, magnetosphere, lithosphere, and from coupling currents between ionosphere and magnetosphere and between hemispheres. Traditionally, the main field (low degree internal field) and magnetospheric field have been modeled simultaneously, and fields from other sources modeled separately. Such a scheme, however, can introduce spurious features. A new model, designated CMP3 (Comprehensive Model: Phase 3), has been derived from quiet-time Magsat and POGO satellite measurements and observatory hourly and annual means measurements as part of an effort to coestimate fields from all of these sources. This model represents a significant advancement in the treatment of the aforementioned field sources over previous attempts, and includes an accounting for main field influences on the magnetosphere, main field and solar activity influences on the ionosphere, seasonal influences on the coupling currents, a priori characterization of ionospheric and magnetospheric influence on Earth-induced fields, and an explicit parameterization and estimation of the lithospheric field. The result of this effort is a model whose fits to the data are generally superior to previous models and whose parameter states for the various constituent sources are very reasonable.

  13. Improved Eddy-current Field Loss Model and Scaling Index for Magnets of Permanent Magnet Synchronous Motors

    Directory of Open Access Journals (Sweden)

    Zhang Lei

    2015-01-01

    Full Text Available The paper gives detailed systematic researches on the mechanism and key factors of eddy-current losses in rotor magnets of high power-density permanent magnet synchronous motors(PMSMs. Firstly, this paper establishes quantitative mathematic model of eddy-current losses for surface-mounted PMSM based on eddy current field model and Maxwell equations. Then, a scaling index is put forward to weigh the key factors relevant to the eddy-current losses in magnets. At the same time, the principles of eddy-current losses in prototype PMSM are analyzed by the finite element analysis (FEA software. The contents researched in the paper have practical reference values for design and reliability analysis of PMSMs.

  14. Field Guide to Plant Model Systems.

    Science.gov (United States)

    Chang, Caren; Bowman, John L; Meyerowitz, Elliot M

    2016-10-06

    For the past several decades, advances in plant development, physiology, cell biology, and genetics have relied heavily on the model (or reference) plant Arabidopsis thaliana. Arabidopsis resembles other plants, including crop plants, in many but by no means all respects. Study of Arabidopsis alone provides little information on the evolutionary history of plants, evolutionary differences between species, plants that survive in different environments, or plants that access nutrients and photosynthesize differently. Empowered by the availability of large-scale sequencing and new technologies for investigating gene function, many new plant models are being proposed and studied. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. The International Reference Ionosphere: Model Update 2016

    Science.gov (United States)

    Bilitza, Dieter; Altadill, David; Reinisch, Bodo; Galkin, Ivan; Shubin, Valentin; Truhlik, Vladimir

    2016-04-01

    The International Reference Ionosphere (IRI) is recognized as the official standard for the ionosphere (COSPAR, URSI, ISO) and is widely used for a multitude of different applications as evidenced by the many papers in science and engineering journals that acknowledge the use of IRI (e.g., about 11% of all Radio Science papers each year). One of the shortcomings of the model has been the dependence of the F2 peak height modeling on the propagation factor M(3000)F2. With the 2016 version of IRI, two new models will be introduced for hmF2 that were developed directly based on hmF2 measurements by ionosondes [Altadill et al., 2013] and by COSMIC radio occultation [Shubin, 2015], respectively. In addition IRI-2016 will include an improved representation of the ionosphere during the very low solar activities that were reached during the last solar minimum in 2008/2009. This presentation will review these and other improvements that are being implemented with the 2016 version of the IRI model. We will also discuss recent IRI workshops and their findings and results. One of the most exciting new projects is the development of the Real-Time IRI [Galkin et al., 2012]. We will discuss the current status and plans for the future. Altadill, D., S. Magdaleno, J.M. Torta, E. Blanch (2013), Global empirical models of the density peak height and of the equivalent scale height for quiet conditions, Advances in Space Research 52, 1756-1769, doi:10.1016/j.asr.2012.11.018. Galkin, I.A., B.W. Reinisch, X. Huang, and D. Bilitza (2012), Assimilation of GIRO Data into a Real-Time IRI, Radio Science, 47, RS0L07, doi:10.1029/2011RS004952. Shubin V.N. (2015), Global median model of the F2-layer peak height based on ionospheric radio-occultation and ground-based Digisonde observations, Advances in Space Research 56, 916-928, doi:10.1016/j.asr.2015.05.029.

  16. Near-field and far-field modeling of scattered surface waves. Application to the apertureless scanning near-field optical microscopy

    International Nuclear Information System (INIS)

    Muller, J.; Parent, G.; Fumeron, S.; Jeandel, G.; Lacroix, D.

    2011-01-01

    The detection of surface waves through scanning near-field optical microscopy (SNOM) is a promising technique for thermal measurements at very small scales. Recent studies have shown that electromagnetic waves, in the vicinity of a scattering structure such as an atomic force microscopy (AFM) tip, can be scattered from near to far-field and thus detected. In the present work, a model based on the finite difference time domain (FDTD) method and the near-field to far-field (NFTFF) transformation for electromagnetic waves propagation is presented. This model has been validated by studying the electromagnetic field of a dipole in vacuum and close to a dielectric substrate. Then simulations for a tetrahedral tip close to an interface are presented and discussed.

  17. A reference model and technical framework for mobile social software for learning

    NARCIS (Netherlands)

    De Jong, Tim; Specht, Marcus; Koper, Rob

    2008-01-01

    De Jong,T., Specht, M., & Koper, R. (2008). A reference model and technical framework for mobile social software for learning. In I. A. Sánchez & P. Isaías (Eds.), Proceedings of the IADIS Mobile Learning Conference 2008 (pp. 206-210). April, 11-13, 2008, Carvoeiro, Portugal.

  18. Reconstructing bidimensional scalar field theory models

    International Nuclear Information System (INIS)

    Flores, Gabriel H.; Svaiter, N.F.

    2001-07-01

    In this paper we review how to reconstruct scalar field theories in two dimensional spacetime starting from solvable Scrodinger equations. Theree different Schrodinger potentials are analyzed. We obtained two new models starting from the Morse and Scarf II hyperbolic potencials, the U (θ) θ 2 In 2 (θ 2 ) model and U (θ) = θ 2 cos 2 (In(θ 2 )) model respectively. (author)

  19. Recent developments in the field of environmental reference materials at the JRC Ispra.

    Science.gov (United States)

    Muntau, H

    2001-06-01

    The production of reference materials for environmental analysis started in the Joint Research Centre at Ispra/Italy in 1972 with the objective of later certification by the BCR, but for obvious budget reasons only a fraction of the total production achieved at Ispra ever reached certification level, although all materials were produced according to the severe quality requirements requested for certified reference materials. Therefore, the materials not destinated to certification are in growing demand as inter-laboratory test materials and as laboratory reference materials, for internal quality control, e.g., by control charts. The history of reference material production within the Joint Research Centre is briefly reviewed and the latest additions described. New developments such as micro-scale reference materials intended for analytical methods requiring sample intakes at milligram or sub-milligram level and therefor not finding supply on the reference material market, and "wet" environmental reference materials, which meet more precisely the "real-world" environmental analysis conditions, are presented and the state-of-the-art discussed.

  20. Development of model reference adaptive control theory for electric power plant control applications

    Energy Technology Data Exchange (ETDEWEB)

    Mabius, L.E.

    1982-09-15

    The scope of this effort includes the theoretical development of a multi-input, multi-output (MIMO) Model Reference Control (MRC) algorithm, (i.e., model following control law), Model Reference Adaptive Control (MRAC) algorithm and the formulation of a nonlinear model of a typical electric power plant. Previous single-input, single-output MRAC algorithm designs have been generalized to MIMO MRAC designs using the MIMO MRC algorithm. This MRC algorithm, which has been developed using Command Generator Tracker methodologies, represents the steady state behavior (in the adaptive sense) of the MRAC algorithm. The MRC algorithm is a fundamental component in the MRAC design and stability analysis. An enhanced MRC algorithm, which has been developed for systems with more controls than regulated outputs, alleviates the MRC stability constraint of stable plant transmission zeroes. The nonlinear power plant model is based on the Cromby model with the addition of a governor valve management algorithm, turbine dynamics and turbine interactions with extraction flows. An application of the MRC algorithm to a linearization of this model demonstrates its applicability to power plant systems. In particular, the generated power changes at 7% per minute while throttle pressure and temperature, reheat temperature and drum level are held constant with a reasonable level of control. The enhanced algorithm reduces significantly control fluctuations without modifying the output response.

  1. Classical field theory

    CERN Document Server

    Franklin, Joel

    2017-01-01

    Classical field theory, which concerns the generation and interaction of fields, is a logical precursor to quantum field theory, and can be used to describe phenomena such as gravity and electromagnetism. Written for advanced undergraduates, and appropriate for graduate level classes, this book provides a comprehensive introduction to field theories, with a focus on their relativistic structural elements. Such structural notions enable a deeper understanding of Maxwell's equations, which lie at the heart of electromagnetism, and can also be applied to modern variants such as Chern–Simons and Born–Infeld. The structure of field theories and their physical predictions are illustrated with compelling examples, making this book perfect as a text in a dedicated field theory course, for self-study, or as a reference for those interested in classical field theory, advanced electromagnetism, or general relativity. Demonstrating a modern approach to model building, this text is also ideal for students of theoretic...

  2. A toy model for single field open inflation

    International Nuclear Information System (INIS)

    Vaudrevange, Pascal M.; Westphal, Alexander

    2012-05-01

    Inflation in an open universe produced by Coleman-De Luccia (CDL) tunneling induces a friction term that is strong enough to allow for successful small-field inflation in models that would otherwise suffer from a severe overshoot problem. In this paper, we present a polynomial scalar potential which allows for a full analysis. This provides a simple model of single-field open inflation on a small-field inflection point after tunneling. We present numerical results and compare them with analytic approximations.

  3. Tensor Fields for Use in Fractional-Order Viscoelasticity

    Science.gov (United States)

    Freed, Alan D.; Diethelm, Kai

    2003-01-01

    To be able to construct viscoelastic material models from fractional0order differentegral equations that are applicable for 3D finite-strain analysis requires definitions for fractional derivatives and integrals for symmetric tensor fields, like stress and strain. We define these fields in the body manifold. We then map them ito spatial fields expressed in terms of an Eulerian or Lagrangian reference frame where most analysts prefer to solve boundary problems.

  4. Field testing of bioenergetic models

    International Nuclear Information System (INIS)

    Nagy, K.A.

    1985-01-01

    Doubly labeled water provides a direct measure of the rate of carbon dioxide production by free-living animals. With appropriate conversion factors, based on chemical composition of the diet and assimilation efficiency, field metabolic rate (FMR), in units of energy expenditure, and field feeding rate can be estimated. Validation studies indicate that doubly labeled water measurements of energy metabolism are accurate to within 7% in reptiles, birds, and mammals. This paper discusses the use of doubly labeled water to generate empirical models for FMR and food requirements for a variety of animals

  5. An improved oxygen diffusion model to explain the effect of low-temperature baking on high field losses in niobium superconducting cavities

    Energy Technology Data Exchange (ETDEWEB)

    Ciovati, Gianluigi

    2006-07-01

    Radio-frequency (RF) superconducting cavities made of high purity niobium are widely used to accelerate charged particle beams in particle accelerators. The major limitation to achieve RF field values approaching the theoretical limit for niobium is represented by ''anomalous'' losses which degrade the quality factor of the cavities starting at peak surface magnetic fields of about 100 mT, in absence of field emission. These high field losses are often referred to as ''Q-drop''. It has been observed that the Q-drop is drastically reduced by baking the cavities at 120 C for about 48 h under ultrahigh vacuum. An improved oxygen diffusion model for the niobium-oxide system is proposed to explain the benefit of the low-temperature baking on the Q-drop in niobium superconducting rf cavities. The model shows that baking at 120 C for 48 h allows oxygen to diffuse away from the surface, and therefore increasing the lower critical field towards the value for pure niobium.

  6. Probabilistic sensitivity analysis for the 'initial defect in the canister' reference model

    International Nuclear Information System (INIS)

    Cormenzana, J. L.

    2013-08-01

    In Posiva Oy's Safety Case 'TURVA-2012' the repository system scenarios leading to radionuclide releases have been identified in Formulation of Radionuclide Release Scenarios. Three potential causes of canister failure and radionuclide release are considered: (i) the presence of an initial defect in the copper shell of one canister that penetrates the shell completely, (ii) corrosion of the copper overpack, that occurs more rapidly if buffer density is reduced, e.g. by erosion, (iii) shear movement on fractures intersecting the deposition hole. All three failure modes are analysed deterministically in Assessment of Radionuclide Release Scenarios, and for the 'initial defect in the canister' reference model a probabilistic sensitivity analysis (PSA) has been carried out. The main steps of the PSA have been: quantification of the uncertainties in the model input parameters through the creation of probability density distributions (PDFs), Monte Carlo simulations of the evolution of the system up to 106 years using parameters values sampled from the previous PDFs. Monte Carlo simulations with 10,000 individual calculations (realisations) have been used in the PSA, quantification of the uncertainty in the model outputs due to uncertainty in the input parameters (uncertainty analysis), and identification of the parameters whose uncertainty have the greatest effect on the uncertainty in the model outputs (sensitivity analysis) Since the biosphere is not included in the Monte Carlo simulations of the system, the model outputs studied are not doses, but total and radionuclide-specific normalised release rates from the near-field and to the biosphere. These outputs are calculated dividing the activity release rates by the constraints on the activity fluxes to the environment set out by the Finnish regulator. Two different cases are analysed in the PSA: (i) the 'hole forever' case, in which the small hole through the copper overpack remains unchanged during the assessment

  7. An improved model for the Earth's gravity field

    Science.gov (United States)

    Tapley, B. D.; Shum, C. K.; Yuan, D. N.; Ries, J. C.; Schutz, B. E.

    1989-01-01

    An improved model for the Earth's gravity field, TEG-1, was determined using data sets from fourteen satellites, spanning the inclination ranges from 15 to 115 deg, and global surface gravity anomaly data. The satellite measurements include laser ranging data, Doppler range-rate data, and satellite-to-ocean radar altimeter data measurements, which include the direct height measurement and the differenced measurements at ground track crossings (crossover measurements). Also determined was another gravity field model, TEG-1S, which included all the data sets in TEG-1 with the exception of direct altimeter data. The effort has included an intense scrutiny of the gravity field solution methodology. The estimated parameters included geopotential coefficients complete to degree and order 50 with selected higher order coefficients, ocean and solid Earth tide parameters, Doppler tracking station coordinates and the quasi-stationary sea surface topography. Extensive error analysis and calibration of the formal covariance matrix indicate that the gravity field model is a significant improvement over previous models and can be used for general applications in geodesy.

  8. Testing of a one dimensional model for Field II calibration

    DEFF Research Database (Denmark)

    Bæk, David; Jensen, Jørgen Arendt; Willatzen, Morten

    2008-01-01

    Field II is a program for simulating ultrasound transducer fields. It is capable of calculating the emitted and pulse-echoed fields for both pulsed and continuous wave transducers. To make it fully calibrated a model of the transducer’s electro-mechanical impulse response must be included. We...... examine an adapted one dimensional transducer model originally proposed by Willatzen [9] to calibrate Field II. This model is modified to calculate the required impulse responses needed by Field II for a calibrated field pressure and external circuit current calculation. The testing has been performed...... to the calibrated Field II program for 1, 4, and 10 cycle excitations. Two parameter sets were applied for modeling, one real valued Pz27 parameter set, manufacturer supplied, and one complex valued parameter set found in literature, Alguer´o et al. [11]. The latter implicitly accounts for attenuation. Results show...

  9. Field Guide to Plant Model Systems

    OpenAIRE

    Chang, Caren; Bowman, John L.; Meyerowitz, Elliot M.

    2016-01-01

    For the past several decades, advances in plant development, physiology, cell biology, and genetics have relied heavily on the model (or reference) plant Arabidopsis thaliana. Arabidopsis resembles other plants, including crop plants, in many but by no means all respects. Study of Arabidopsis alone provides little information on the evolutionary history of plants, evolutionary differences between species, plants that survive in different environments, or plants that access nutrients and photo...

  10. The phase field technique for modeling multiphase materials

    Science.gov (United States)

    Singer-Loginova, I.; Singer, H. M.

    2008-10-01

    This paper reviews methods and applications of the phase field technique, one of the fastest growing areas in computational materials science. The phase field method is used as a theory and computational tool for predictions of the evolution of arbitrarily shaped morphologies and complex microstructures in materials. In this method, the interface between two phases (e.g. solid and liquid) is treated as a region of finite width having a gradual variation of different physical quantities, i.e. it is a diffuse interface model. An auxiliary variable, the phase field or order parameter \\phi(\\vec{x}) , is introduced, which distinguishes one phase from the other. Interfaces are identified by the variation of the phase field. We begin with presenting the physical background of the phase field method and give a detailed thermodynamical derivation of the phase field equations. We demonstrate how equilibrium and non-equilibrium physical phenomena at the phase interface are incorporated into the phase field methods. Then we address in detail dendritic and directional solidification of pure and multicomponent alloys, effects of natural convection and forced flow, grain growth, nucleation, solid-solid phase transformation and highlight other applications of the phase field methods. In particular, we review the novel phase field crystal model, which combines atomistic length scales with diffusive time scales. We also discuss aspects of quantitative phase field modeling such as thin interface asymptotic analysis and coupling to thermodynamic databases. The phase field methods result in a set of partial differential equations, whose solutions require time-consuming large-scale computations and often limit the applicability of the method. Subsequently, we review numerical approaches to solve the phase field equations and present a finite difference discretization of the anisotropic Laplacian operator.

  11. One biquaternion model of electro-gravimagnetic field. Field analogues of Newton laws

    OpenAIRE

    Alexeyeva, Lyudmila A.

    2007-01-01

    Using the biquaternions algebra with involution and mutual quaternional gradients the equations of one model of electro-gravimagnetic (EGM) field are constructed on the base of Hamilton form of Maxwell equations. For this field the hypothesis of equivalence of magnetic charge to gravitational mass is implied. The equations of interaction of generated by different charges and currents EGM-fields are built. On its base the analogies of three Newton's laws are obtained. The laws of transformatio...

  12. Endogenizing Prospect Theory's Reference Point

    OpenAIRE

    Ulrich Schmidt; Horst Zank

    2010-01-01

    In previous models of (cumulative) prospect theory reference-dependence of preferences is imposed beforehand and the location of the reference point is exogenously determined. This note provides a foundation of prospect theory, where reference-dependence is derived from preference conditions and a unique reference point arises endogenously.

  13. German activities towards a thermodynamic reference data base

    Energy Technology Data Exchange (ETDEWEB)

    Herbert, H.J.; Hagemann, S. [Gesellschaft fuer Anlagen- und Reaktorsicherheit mbH (GRS), Braunschweig (Germany); Brendler, V. [Forschungszentrum Rossendorf, Institut fur Radiochemie, Dresden (Germany); Marquardt, Ch. [Forschungszentrum Karlsruhe, Institut fur Nukleare Entsorgung, Karlsruhe (Germany); Voigt, W. [Technische Univ. Bergakademie Freiberg, Freiberg (Germany); Wilhelm, S. [Colenco Power Engineering, Baden (Switzerland)

    2006-07-01

    Leading research centres in the field of radioactive waste disposal in Germany have decided to combine their efforts in order to achieve a common goal, the development of a comprehensive and consistent thermodynamic reference database. All the thermodynamic data needed for the modelling of geochemical near- and far field processes in the geological media for high level waste repositories presently under discussion in Germany (salt, clay, granite) shall be collected and qualified in a single database. The partners participating in the project are a group of experts, who are generating, collecting and evaluating thermodynamic data of all relevant radionuclides and matrix elements according to uniform previously established and internationally accepted criteria. Special attention will be given to complete documentation and traceability of all data entries in the database. Existing data from international databases such as those of NEA, NAGRA, YMP will be integrated. Ion interaction coefficients (SIT, Pitzer) needed for modelling in a high saline environment will be included also. (authors)

  14. German activities towards a thermodynamic reference data base

    International Nuclear Information System (INIS)

    Herbert, H.J.; Hagemann, S.; Brendler, V.; Marquardt, Ch.; Voigt, W.; Wilhelm, S.

    2006-01-01

    Leading research centres in the field of radioactive waste disposal in Germany have decided to combine their efforts in order to achieve a common goal, the development of a comprehensive and consistent thermodynamic reference database. All the thermodynamic data needed for the modelling of geochemical near- and far field processes in the geological media for high level waste repositories presently under discussion in Germany (salt, clay, granite) shall be collected and qualified in a single database. The partners participating in the project are a group of experts, who are generating, collecting and evaluating thermodynamic data of all relevant radionuclides and matrix elements according to uniform previously established and internationally accepted criteria. Special attention will be given to complete documentation and traceability of all data entries in the database. Existing data from international databases such as those of NEA, NAGRA, YMP will be integrated. Ion interaction coefficients (SIT, Pitzer) needed for modelling in a high saline environment will be included also. (authors)

  15. A lithospheric magnetic field model derived from the Swarm satellite magnetic field measurements

    Science.gov (United States)

    Hulot, G.; Thebault, E.; Vigneron, P.

    2015-12-01

    The Swarm constellation of satellites was launched in November 2013 and has since then delivered high quality scalar and vector magnetic field measurements. A consortium of several research institutions was selected by the European Space Agency (ESA) to provide a number of scientific products which will be made available to the scientific community. Within this framework, specific tools were tailor-made to better extract the magnetic signal emanating from Earth's the lithospheric. These tools rely on the scalar gradient measured by the lower pair of Swarm satellites and rely on a regional modeling scheme that is more sensitive to small spatial scales and weak signals than the standard spherical harmonic modeling. In this presentation, we report on various activities related to data analysis and processing. We assess the efficiency of this dedicated chain for modeling the lithospheric magnetic field using more than one year of measurements, and finally discuss refinements that are continuously implemented in order to further improve the robustness and the spatial resolution of the lithospheric field model.

  16. Regularity of solutions of a phase field model

    KAUST Repository

    Amler, Thomas

    2013-01-01

    Phase field models are widely-used for modelling phase transition processes such as solidification, freezing or CO2 sequestration. In this paper, a phase field model proposed by G. Caginalp is considered. The existence and uniqueness of solutions are proved in the case of nonsmooth initial data. Continuity of solutions with respect to time is established. In particular, it is shown that the governing initial boundary value problem can be considered as a dynamical system. © 2013 International Press.

  17. On the invariance of world time reference system

    International Nuclear Information System (INIS)

    Asanov, G.S.

    1978-01-01

    A universal reference system is studied. It is shown that time differentiation acquires an invariant meaning in the covariant theory of a curved space-time. All the principal covariant equations of the Einstein gravitational field theory can be interpreted successively relative to a universal reference system, whose base congruence is the S-congruence. The Lorentz calibration conditions determine the base tetrades of the universal reference system with an accuracy to rigid spatial rotations with constant coefficients. The use of rigid tetrades eliminates the ambiguity in the interpretation of the value of the energy momentum of a gravitational field

  18. Evaluation of using digital gravity field models for zoning map creation

    Science.gov (United States)

    Loginov, Dmitry

    2018-05-01

    At the present time the digital cartographic models of geophysical fields are taking a special significance into geo-physical mapping. One of the important directions to their application is the creation of zoning maps, which allow taking into account the morphology of geophysical field in the implementation automated choice of contour intervals. The purpose of this work is the comparative evaluation of various digital models in the creation of integrated gravity field zoning map. For comparison were chosen the digital model of gravity field of Russia, created by the analog map with scale of 1 : 2 500 000, and the open global model of gravity field of the Earth - WGM2012. As a result of experimental works the four integrated gravity field zoning maps were obtained with using raw and processed data on each gravity field model. The study demonstrates the possibility of open data use to create integrated zoning maps with the condition to eliminate noise component of model by processing in specialized software systems. In this case, for solving problem of contour intervals automated choice the open digital models aren't inferior to regional models of gravity field, created for individual countries. This fact allows asserting about universality and independence of integrated zoning maps creation regardless of detail of a digital cartographic model of geo-physical fields.

  19. The International Reference Ionosphere 2012 – a model of international collaboration

    Czech Academy of Sciences Publication Activity Database

    Bilitza, D.; Altadill, D.; Zhang, Y.; Mertens, Ch.; Truhlík, Vladimír; Richards, P.; McKinnell, L.- A.; Reinisch, B.

    2014-01-01

    Roč. 4, 20 February (2014), A07/1-A07/12 ISSN 2115-7251 R&D Projects: GA MŠk(CZ) LH11123 Institutional support: RVO:68378289 Keywords : International Reference Ionosphere * empirical models * plasma parameters * real - time IRI Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 2.558, year: 2014 http://www.swsc-journal.org/articles/swsc/abs/2014/01/swsc130043/swsc130043.html

  20. Relativistic mean-field mass models

    Energy Technology Data Exchange (ETDEWEB)

    Pena-Arteaga, D.; Goriely, S.; Chamel, N. [Universite Libre de Bruxelles, Institut d' Astronomie et d' Astrophysique, CP-226, Brussels (Belgium)

    2016-10-15

    We present a new effort to develop viable mass models within the relativistic mean-field approach with density-dependent meson couplings, separable pairing and microscopic estimations for the translational and rotational correction energies. Two interactions, DD-MEB1 and DD-MEB2, are fitted to essentially all experimental masses, and also to charge radii and infinite nuclear matter properties as determined by microscopic models using realistic interactions. While DD-MEB1 includes the σ, ω and ρ meson fields, DD-MEB2 also considers the δ meson. Both mass models describe the 2353 experimental masses with a root mean square deviation of about 1.1 MeV and the 882 measured charge radii with a root mean square deviation of 0.029 fm. In addition, we show that the Pb isotopic shifts and moments of inertia are rather well reproduced, and the equation of state in pure neutron matter as well as symmetric nuclear matter are in relatively good agreement with existing realistic calculations. Both models predict a maximum neutron-star mass of more than 2.6 solar masses, and thus are able to accommodate the heaviest neutron stars observed so far. However, the new Lagrangians, like all previously determined RMF models, present the drawback of being characterized by a low effective mass, which leads to strong shell effects due to the strong coupling between the spin-orbit splitting and the effective mass. Complete mass tables have been generated and a comparison with other mass models is presented. (orig.)

  1. Optimization of Saturn paraboloid magnetospheric field model parameters using Cassini equatorial magnetic field data

    Directory of Open Access Journals (Sweden)

    E. S. Belenkaya

    2016-07-01

    Full Text Available The paraboloid model of Saturn's magnetosphere describes the magnetic field as being due to the sum of contributions from the internal field of the planet, the ring current, and the tail current, all contained by surface currents inside a magnetopause boundary which is taken to be a paraboloid of revolution about the planet-Sun line. The parameters of the model have previously been determined by comparison with data from a few passes through Saturn's magnetosphere in compressed and expanded states, depending on the prevailing dynamic pressure of the solar wind. Here we significantly expand such comparisons through examination of Cassini magnetic field data from 18 near-equatorial passes that span wide ranges of local time, focusing on modelling the co-latitudinal field component that defines the magnetic flux passing through the equatorial plane. For 12 of these passes, spanning pre-dawn, via noon, to post-midnight, the spacecraft crossed the magnetopause during the pass, thus allowing an estimate of the concurrent subsolar radial distance of the magnetopause R1 to be made, considered to be the primary parameter defining the scale size of the system. The best-fit model parameters from these passes are then employed to determine how the parameters vary with R1, using least-squares linear fits, thus providing predictive model parameters for any value of R1 within the range. We show that the fits obtained using the linear approximation parameters are of the same order as those for the individually selected parameters. We also show that the magnetic flux mapping to the tail lobes in these models is generally in good accord with observations of the location of the open-closed field line boundary in Saturn's ionosphere, and the related position of the auroral oval. We then investigate the field data on six passes through the nightside magnetosphere, for which the spacecraft did not cross the magnetopause, such that in this case we compare the

  2. Wave Disturbance Reduction of a Floating Wind Turbine Using a Reference Model-based Predictive Control

    DEFF Research Database (Denmark)

    Christiansen, Søren; Tabatabaeipour, Seyed Mojtaba; Bak, Thomas

    2013-01-01

    pitch such that the state trajectories of the controlled system tracks the reference trajectories. The framework is demonstrated with a reference model of the desired closed-loop system undisturbed by the incident waves. This allows the wave-induced motion of the platform to be damped significantly...... compared to a baseline floating wind turbine controller at the cost of more pitch action....

  3. Antineutrinos from Earth: A reference model and its uncertainties

    International Nuclear Information System (INIS)

    Mantovani, Fabio; Carmignani, Luigi; Fiorentini, Gianni; Lissia, Marcello

    2004-01-01

    We predict geoneutrino fluxes in a reference model based on a detailed description of Earth's crust and mantle and using the best available information on the abundances of uranium, thorium, and potassium inside Earth's layers. We estimate the uncertainties of fluxes corresponding to the uncertainties of the element abundances. In addition to distance integrated fluxes, we also provide the differential fluxes as a function of distance from several sites of experimental interest. Event yields at several locations are estimated and their dependence on the neutrino oscillation parameters is discussed. At Kamioka we predict N(U+Th)=35±6 events for 10 32 proton yr and 100% efficiency assuming sin 2 (2θ)=0.863 and δm 2 =7.3x10 -5 eV 2 . The maximal prediction is 55 events, obtained in a model with fully radiogenic production of the terrestrial heat flow

  4. Establishing a Business Process Reference Model for Universities

    KAUST Repository

    Svensson, Carsten; Hvolby, Hans-Henrik

    2012-01-01

    Reference), DCOR (Design Chain Operations Reference) and ITIL (Information Technology Infrastructure Library) have gained popularity among organizations in both the private and public sectors. We speculate that this success can be replicated in a university

  5. Some variations of the Kristallin-I near-field model

    International Nuclear Information System (INIS)

    Smith, P.A.; Curti, E.

    1995-11-01

    The Kristallin-I project is an integrated analysis of the final disposal of vitrified high-level radioactive waste (HLW) in the crystalline basement of Northern Switzerland. It includes an analysis of the radiological consequences of radionuclide release from a repository. This analysis employs a chain of independent models for the near-field, geosphere and biosphere. In constructing these models, processes are incorporated that are believed to be relevant to repository safety, while other processes are neglected. In the present report, a set of simplified, steady-state models of the near-field is developed to investigate the possible effects of specific processes which are neglected in the time-dependent Kristallin-I near-field model. These processes are neglected, either because they are thought unlikely to occur to a significant degree, or because they are likely to make a positive contribution to the performance of the near-field barrier to radionuclide migration, but are insufficiently understood to justify incorporating them in a safety assessment. The aim of this report is to investigate whether the arguments for neglecting these processes in the Kristallin-I near-field model can be justified. (author) figs., tabs., refs

  6. Certified reference materials for food packaging specific migration tests: development, validation and modelling

    NARCIS (Netherlands)

    Stoffers, N.H.

    2005-01-01

    Keywords:certified reference materials; diffusion; food contact materials; food packaging; laurolactam; migration modelling; nylon; specific migration This thesis compiles several research topics

  7. Field validation of the contaminant transport model, FEMA

    International Nuclear Information System (INIS)

    Wong, K.-F.V.

    1986-01-01

    The work describes the validation with field data of a finite element model of material transport through aquifers (FEMA). Field data from the Idaho Chemical Processing Plant, Idaho, USA and from the 58th Street landfill in Miami, Florida, USA are used. In both cases the model was first calibrated and then integrated over a span of eight years to check on the predictive capability of the model. Both predictive runs gave results that matched well with available data. (author)

  8. Fetal exposure to low frequency electric and magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Cech, R; Leitgeb, N; Pediaditis, M [Institute of Clinical Engineering, Graz University of Technology, Inffeldgasse 18, 8010 Graz (Austria)

    2007-02-21

    To investigate the interaction of low frequency electric and magnetic fields with pregnant women and in particular with the fetus, an anatomical voxel model of an 89 kg woman at week 30 of pregnancy was developed. Intracorporal electric current density distributions due to exposure to homogeneous 50 Hz electric and magnetic fields were calculated and results were compared with basic restrictions recommended by ICNIRP guidelines. It could be shown that the basic restriction is met within the central nervous system (CNS) of the mother at exposure to reference level of either electric or magnetic fields. However, within the fetus the basic restriction is considerably exceeded. Revision of reference levels might be necessary.

  9. Fetal exposure to low frequency electric and magnetic fields

    International Nuclear Information System (INIS)

    Cech, R; Leitgeb, N; Pediaditis, M

    2007-01-01

    To investigate the interaction of low frequency electric and magnetic fields with pregnant women and in particular with the fetus, an anatomical voxel model of an 89 kg woman at week 30 of pregnancy was developed. Intracorporal electric current density distributions due to exposure to homogeneous 50 Hz electric and magnetic fields were calculated and results were compared with basic restrictions recommended by ICNIRP guidelines. It could be shown that the basic restriction is met within the central nervous system (CNS) of the mother at exposure to reference level of either electric or magnetic fields. However, within the fetus the basic restriction is considerably exceeded. Revision of reference levels might be necessary

  10. Conformal FDTD modeling of 3-D wake fields

    International Nuclear Information System (INIS)

    Jurgens, T.G.; Harfoush, F.A.

    1991-01-01

    Many computer codes have been written to model wake fields. Here the authors describe the use of the Conformal Finite Difference Time Domain (CFDTD) method to model the wake fields generated by a rigid beam traveling through various accelerating structures. The non-cylindrical symmetry of some of the problems considered here requires the use of a three dimensional code. In traditional FDTD codes, curved surfaces are approximated by rectangular steps. The errors introduced in wake field calculations by such an approximation can be reduced by increasing the mesh size, therefore increasing the cost of computing. Another approach, validated here, deforms Ampere and Faraday contours near a media interface so as to conform to the interface. These improvements so as to conform to the interface. These improvements to the FDTD method result in better accuracy of the fields at asymptotically no computational cost. This method is also capable of modeling thin wires as found in beam profile monitors, and slots and cracks as found in resistive wall monitors

  11. Plasma pressure and anisotropy inferred from the Tsyganenkomagnetic field model

    Directory of Open Access Journals (Sweden)

    F. Cao

    Full Text Available A numerical procedure has been developed to deduce the plasma pressure and anisotropy from the Tsyganenko magnetic field model. The Tsyganenko empirical field model, which is based on vast satellite field data, provides a realistic description of magnetic field configuration in the magnetosphere. When the force balance under the static condition is assumed, the electromagnetic J×B force from the Tsyganenko field model can be used to infer the plasma pressure and anisotropy distributions consistent with the field model. It is found that the J×B force obtained from the Tsyganenko field model is not curl-free. The curl-free part of the J×B force in an empirical field model can be balanced by the gradient of the isotropic pressure, while the nonzero curl of the J×B force can only be associated with the pressure anisotropy. The plasma pressure and anisotropy in the near-Earth plasma sheet are numerically calculated to obtain a static equilibrium consistent with the Tsyganenko field model both in the noon-midnight meridian and in the equatorial plane. The plasma pressure distribution deduced from the Tsyganenko 1989 field model is highly anisotropic and shows this feature early in the substorm growth phase. The pressure anisotropy parameter αP, defined as αP=1-PVertP, is typically ~0.3 at x ≈ -4.5RE and gradually decreases to a small negative value with an increasing tailward distance. The pressure anisotropy from the Tsyganenko 1989 model accounts for 50% of the cross-tail current at maximum and only in a highly localized region near xsim-10RE. In comparison, the plasma pressure anisotropy inferred from the Tsyganenko 1987 model is much smaller. We also find that the boundary

  12. Particles and scaling for lattice fields and Ising models

    International Nuclear Information System (INIS)

    Glimm, J.; Jaffe, A.

    1976-01-01

    The conjectured inequality GAMMA 6 4 -fields and the scaling limit for d-dimensional Ising models. Assuming GAMMA 6 = 6 these phi 4 fields are free fields unless the field strength renormalization Z -1 diverges. (orig./BJ) [de

  13. Technical Work Plan for: Near Field Environment: Engineered Barrier System: Radionuclide Transport Abstraction Model Report

    International Nuclear Information System (INIS)

    J.D. Schreiber

    2006-01-01

    This technical work plan (TWP) describes work activities to be performed by the Near-Field Environment Team. The objective of the work scope covered by this TWP is to generate Revision 03 of EBS Radionuclide Transport Abstraction, referred to herein as the radionuclide transport abstraction (RTA) report. The RTA report is being revised primarily to address condition reports (CRs), to address issues identified by the Independent Validation Review Team (IVRT), to address the potential impact of transport, aging, and disposal (TAD) canister design on transport models, and to ensure integration with other models that are closely associated with the RTA report and being developed or revised in other analysis/model reports in response to IVRT comments. The RTA report will be developed in accordance with the most current version of LP-SIII.10Q-BSC and will reflect current administrative procedures (LP-3.15Q-BSC, ''Managing Technical Product Inputs''; LP-SIII.2Q-BSC, ''Qualification of Unqualified Data''; etc.), and will develop related Document Input Reference System (DIRS) reports and data qualifications as applicable in accordance with prevailing procedures. The RTA report consists of three models: the engineered barrier system (EBS) flow model, the EBS transport model, and the EBS-unsaturated zone (UZ) interface model. The flux-splitting submodel in the EBS flow model will change, so the EBS flow model will be validated again. The EBS transport model and validation of the model will be substantially revised in Revision 03 of the RTA report, which is the main subject of this TWP. The EBS-UZ interface model may be changed in Revision 03 of the RTA report due to changes in the conceptualization of the UZ transport abstraction model (a particle tracker transport model based on the discrete fracture transfer function will be used instead of the dual-continuum transport model previously used). Validation of the EBS-UZ interface model will be revised to be consistent with

  14. Conducting field studies for testing pesticide leaching models

    Science.gov (United States)

    Smith, Charles N.; Parrish, Rudolph S.; Brown, David S.

    1990-01-01

    A variety of predictive models are being applied to evaluate the transport and transformation of pesticides in the environment. These include well known models such as the Pesticide Root Zone Model (PRZM), the Risk of Unsaturated-Saturated Transport and Transformation Interactions for Chemical Concentrations Model (RUSTIC) and the Groundwater Loading Effects of Agricultural Management Systems Model (GLEAMS). The potentially large impacts of using these models as tools for developing pesticide management strategies and regulatory decisions necessitates development of sound model validation protocols. This paper offers guidance on many of the theoretical and practical problems encountered in the design and implementation of field-scale model validation studies. Recommendations are provided for site selection and characterization, test compound selection, data needs, measurement techniques, statistical design considerations and sampling techniques. A strategy is provided for quantitatively testing models using field measurements.

  15. Testing and reference model analysis of FTTH system

    Science.gov (United States)

    Feng, Xiancheng; Cui, Wanlong; Chen, Ying

    2009-08-01

    With rapid development of Internet and broadband access network, the technologies of xDSL, FTTx+LAN , WLAN have more applications, new network service emerges in endless stream, especially the increase of network game, meeting TV, video on demand, etc. FTTH supports all present and future service with enormous bandwidth, including traditional telecommunication service, traditional data service and traditional TV service, and the future digital TV and VOD. With huge bandwidth of FTTH, it wins the final solution of broadband network, becomes the final goal of development of optical access network.. Fiber to the Home (FTTH) will be the goal of telecommunications cable broadband access. In accordance with the development trend of telecommunication services, to enhance the capacity of integrated access network, to achieve triple-play (voice, data, image), based on the existing optical Fiber to the curb (FTTC), Fiber To The Zone (FTTZ), Fiber to the Building (FTTB) user optical cable network, the optical fiber can extend to the FTTH system of end-user by using EPON technology. The article first introduced the basic components of FTTH system; and then explain the reference model and reference point for testing of the FTTH system; Finally, by testing connection diagram, the testing process, expected results, primarily analyze SNI Interface Testing, PON interface testing, Ethernet performance testing, UNI interface testing, Ethernet functional testing, PON functional testing, equipment functional testing, telephone functional testing, operational support capability testing and so on testing of FTTH system. ...

  16. Quantification of source-term profiles from near-field geochemical models

    International Nuclear Information System (INIS)

    McKinley, I.G.

    1985-01-01

    A geochemical model of the near-field is described which quantitatively treats the processes of engineered barrier degradation, buffering of aqueous chemistry by solid phases, nuclide solubilization and transport through the near-field and release to the far-field. The radionuclide source-terms derived from this model are compared with those from a simpler model used for repository safety analysis. 10 refs., 2 figs., 2 tabs

  17. Cortico-Cortical Receptive Field Estimates in Human Visual Cortex

    Directory of Open Access Journals (Sweden)

    Koen V Haak

    2012-05-01

    Full Text Available Human visual cortex comprises many visual areas that contain a map of the visual field (Wandell et al 2007, Neuron 56, 366–383. These visual field maps can be identified readily in individual subjects with functional magnetic resonance imaging (fMRI during experimental sessions that last less than an hour (Wandell and Winawer 2011, Vis Res 718–737. Hence, visual field mapping with fMRI has been, and still is, a heavily used technique to examine the organisation of both normal and abnormal human visual cortex (Haak et al 2011, ACNR, 11(3, 20–21. However, visual field mapping cannot reveal every aspect of human visual cortex organisation. For example, the information processed within a visual field map arrives from somewhere and is sent to somewhere, and visual field mapping does not derive these input/output relationships. Here, we describe a new, model-based analysis for estimating the dependence between signals in distinct cortical regions using functional magnetic resonance imaging (fMRI data. Just as a stimulus-referred receptive field predicts the neural response as a function of the stimulus contrast, the neural-referred receptive field predicts the neural response as a function of responses elsewhere in the nervous system. When applied to two cortical regions, this function can be called the cortico-cortical receptive field (CCRF. We model the CCRF as a Gaussian-weighted region on the cortical surface and apply the model to data from both stimulus-driven and resting-state experimental conditions in visual cortex.

  18. An empirical model describing the postnatal growth of organs in ICRP reference humans: Pt. 1

    International Nuclear Information System (INIS)

    Walker, J.T.

    1991-01-01

    An empirical model is presented for describing the postnatal mass growth of lungs in ICRP reference humans. A combined exponential and logistic function containing six parameters is fitted to ICRP 23 lung data using a weighted non-linear least squares technique. The results indicate that the model delineates the data well. Further analysis shows that reference male lungs attain a higher pubertal peak velocity (PPV) and adult mass size than female lungs, although the latter reach their PPV and adult mass size first. Furthermore, the model shows that lung growth rates in infants are two to three orders of magnitude higher than those in mature adults. This finding is important because of the possible association between higher radiation risks in infants' organs that have faster cell turnover rates compared to mature adult organs. The significance of the model for ICRP dosimetric purposes will be discussed. (author)

  19. Correlation of spacecraft thermal mathematical models to reference data

    Science.gov (United States)

    Torralbo, Ignacio; Perez-Grande, Isabel; Sanz-Andres, Angel; Piqueras, Javier

    2018-03-01

    Model-to-test correlation is a frequent problem in spacecraft-thermal control design. The idea is to determine the values of the parameters of the thermal mathematical model (TMM) that allows reaching a good fit between the TMM results and test data, in order to reduce the uncertainty of the mathematical model. Quite often, this task is performed manually, mainly because a good engineering knowledge and experience is needed to reach a successful compromise, but the use of a mathematical tool could facilitate this work. The correlation process can be considered as the minimization of the error of the model results with regard to the reference data. In this paper, a simple method is presented suitable to solve the TMM-to-test correlation problem, using Jacobian matrix formulation and Moore-Penrose pseudo-inverse, generalized to include several load cases. Aside, in simple cases, this method also allows for analytical solutions to be obtained, which helps to analyze some problems that appear when the Jacobian matrix is singular. To show the implementation of the method, two problems have been considered, one more academic, and the other one the TMM of an electronic box of PHI instrument of ESA Solar Orbiter mission, to be flown in 2019. The use of singular value decomposition of the Jacobian matrix to analyze and reduce these models is also shown. The error in parameter space is used to assess the quality of the correlation results in both models.

  20. Ionospheric Tomography from a Reference GPS/MET Experiment Through the IRI Model

    Directory of Open Access Journals (Sweden)

    Lung-Chih Tsai

    2006-01-01

    Full Text Available In earlier studies, we implemented the Multiplicative Algebraic Reconstruction Technique (MART to reconstruct two-dimensional ionospheric structures from measured TECs through the receptions of the GPS-to-LEO signals and/or the NNSS-to-ground beacon signals. To examine the accuracy of the reconstructed image we need ground-based validation systems which are difficult to obtain. However, such comparative investigation is needed if one aims to improve tomography inverse techniques and algorithms. In this study, we propose a simulation scheme to carry out this task. We first simulate the GPS-to-LEO TEC measurements through the IRI model by integrating electron densities along the ¡§straight¡¨ ray occultation paths between the GPS and LEO satellite obtained from the real GPS/MET experiment. Contiguous tomographic images are then derived by the MART algorithm within the ¡§reference¡¨ GPS/MET experiment. They are verified by comparison with the ¡§true¡¨ IRI-modelled ionosphere. We show that simulation/reference results can be used to find the optimal reconstruction strategy in space-based ionospheric tomography.

  1. Heavy-ion interactions in relativistic mean-field models

    International Nuclear Information System (INIS)

    Rashdan, M.

    1996-01-01

    The interaction potential between spherical nuclei and the elastic scattering cross section are calculated within relativistic mean-field (linear and non-linear) models, using a generalized relativistic local density approximation. The nuclear densities are calculated self-consistently from the solution of the relativistic mean-field equations. It is found that both the linear and non-linear models predict the characteristic switching-over phenomenon of the heavy-ion nuclear potential, where the potential gets attraction with increasing energy up to some value where it reverses this behaviour. The non-linear NLC model predicts a deeper potential than the linear LW model. The elastic scattering cross section calculated within the non-linear NLC model is in better agreement with experiments than that calculated within the linear LW model. (orig.)

  2. A quasi-hemispheric model of the Hermean's magnetic field

    Science.gov (United States)

    Thebault, E.; Oliveira, J.; Langlais, B.; Amit, H.

    2015-10-01

    We analyse and process magnetic field measurements provided by the MErcury Surface, Space ENvironment, Geochemistry, and Ranging (MESSENGER) mission. The vect or magnetic field measurements are modelled with a dedicated regional scheme expanded in space and in time. Compared to the widely used global Spherical Harmonics (SH), the regional approach is particularly well suited because the partial and quasi hemispheric distribution of the MESSENGER data represents no major numerical difficulty. We confirm that the internal magnetic field of Mercury is mostly axisymmetric with a magnetic equator shifted northward. However, we also observe a time dependency in the model that is at present hardly explained only by time variations of the external magnetic fields. We present the major spatial and temporal structures shown by the regional model.

  3. Reference Sources in Chemistry

    OpenAIRE

    Sthapit, Dilip Man

    1995-01-01

    Information plays an important role in the development of every field. Therefore a brief knowledge regarding information sources is necessary to function in any field. There are many information sources about scientific and technical subjects. In this context there are many reference sources in Chemistry too. Chemistry is one important part of the science which deals with the study of the composition of substances and the chemical changes that they undergo. The purpose of this report is...

  4. Two-field axion-monodromy hybrid inflation model: Dante's Waterfall

    Science.gov (United States)

    Carone, Christopher D.; Erlich, Joshua; Sensharma, Anuraag; Wang, Zhen

    2015-02-01

    We describe a hybrid axion-monodromy inflation model motivated by the Dante's Inferno scenario. In Dante's Inferno, a two-field potential features a stable trench along which a linear combination of the two fields slowly rolls, rendering the dynamics essentially identical to that of single-field chaotic inflation. A shift symmetry allows for the Lyth bound to be effectively evaded as in other axion-monodromy models. In our proposal, the potential is concave downward near the origin and the inflaton trajectory is a gradual downward spiral, ending at a point where the trench becomes unstable. There, the fields begin falling rapidly towards the minimum of the potential and inflation terminates as in a hybrid model. We find parameter choices that reproduce observed features of the cosmic microwave background, and discuss our model in light of recent results from the BICEP2 and Planck experiments.

  5. H+3 WZNW model from Liouville field theory

    International Nuclear Information System (INIS)

    Hikida, Yasuaki; Schomerus, Volker

    2007-01-01

    There exists an intriguing relation between genus zero correlation functions in the H + 3 WZNW model and in Liouville field theory. We provide a path integral derivation of the correspondence and then use our new approach to generalize the relation to surfaces of arbitrary genus g. In particular we determine the correlation functions of N primary fields in the WZNW model explicitly through Liouville correlators with N+2g-2 additional insertions of certain degenerate fields. The paper concludes with a list of interesting further extensions and a few comments on the relation to the geometric Langlands program

  6. Thermodynamically Consistent Algorithms for the Solution of Phase-Field Models

    KAUST Repository

    Vignal, Philippe

    2016-01-01

    of thermodynamically consistent algorithms for time integration of phase-field models. The first part of this thesis focuses on an energy-stable numerical strategy developed for the phase-field crystal equation. This model was put forward to model microstructure

  7. Linear velocity fields in non-Gaussian models for large-scale structure

    Science.gov (United States)

    Scherrer, Robert J.

    1992-01-01

    Linear velocity fields in two types of physically motivated non-Gaussian models are examined for large-scale structure: seed models, in which the density field is a convolution of a density profile with a distribution of points, and local non-Gaussian fields, derived from a local nonlinear transformation on a Gaussian field. The distribution of a single component of the velocity is derived for seed models with randomly distributed seeds, and these results are applied to the seeded hot dark matter model and the global texture model with cold dark matter. An expression for the distribution of a single component of the velocity in arbitrary local non-Gaussian models is given, and these results are applied to such fields with chi-squared and lognormal distributions. It is shown that all seed models with randomly distributed seeds and all local non-Guassian models have single-component velocity distributions with positive kurtosis.

  8. Mathematical Practice in Textbooks Analysis: Praxeological Reference Models, the Case of Proportion

    Science.gov (United States)

    Wijayanti, Dyana; Winsløw, Carl

    2017-01-01

    We present a new method in textbook analysis, based on so-called praxeological reference models focused on specific content at task level. This method implies that the mathematical contents of a textbook (or textbook part) is analyzed in terms of the tasks and techniques which are exposed to or demanded from readers; this can then be interpreted…

  9. Impact of the choice of the precipitation reference data set on climate model selection and the resulting climate change signal

    Science.gov (United States)

    Gampe, D.; Ludwig, R.

    2017-12-01

    Regional Climate Models (RCMs) that downscale General Circulation Models (GCMs) are the primary tool to project future climate and serve as input to many impact models to assess the related changes and impacts under such climate conditions. Such RCMs are made available through the Coordinated Regional climate Downscaling Experiment (CORDEX). The ensemble of models provides a range of possible future climate changes around the ensemble mean climate change signal. The model outputs however are prone to biases compared to regional observations. A bias correction of these deviations is a crucial step in the impact modelling chain to allow the reproduction of historic conditions of i.e. river discharge. However, the detection and quantification of model biases are highly dependent on the selected regional reference data set. Additionally, in practice due to computational constraints it is usually not feasible to consider the entire ensembles of climate simulations with all members as input for impact models which provide information to support decision-making. Although more and more studies focus on model selection based on the preservation of the climate model spread, a selection based on validity, i.e. the representation of the historic conditions is still a widely applied approach. In this study, several available reference data sets for precipitation are selected to detect the model bias for the reference period 1989 - 2008 over the alpine catchment of the Adige River located in Northern Italy. The reference data sets originate from various sources, such as station data or reanalysis. These data sets are remapped to the common RCM grid at 0.11° resolution and several indicators, such as dry and wet spells, extreme precipitation and general climatology, are calculate to evaluate the capability of the RCMs to produce the historical conditions. The resulting RCM spread is compared against the spread of the reference data set to determine the related uncertainties and

  10. Postural adaptation of the spatial reference frames to microgravity: back to the egocentric reference frame.

    Directory of Open Access Journals (Sweden)

    Sébastien Viel

    Full Text Available BACKGROUND: In order to test how gravitational information would affect the choice of stable reference frame used to control posture and voluntary movement, we have analysed the forearm stabilisation during sit to stand movement under microgravity condition obtained during parabolic flights. In this study, we hypothesised that in response to the transient loss of graviceptive information, the postural adaptation might involve the use of several strategies of segmental stabilisation, depending on the subject's perceptual typology (dependence--independence with respect to the visual field. More precisely, we expected a continuum of postural strategies across subjects with 1 at one extreme the maintaining of an egocentric reference frame and 2 at the other the re-activation of childhood strategies consisting in adopting an egocentric reference frame. METHODOLOGY/PRINCIPAL FINDINGS: To check this point, a forearm stabilisation task combined with a sit to stand movement was performed with eyes closed by 11 subjects during parabolic flight campaigns. Kinematic data were collected during 1-g and 0-g periods. The postural adaptation to microgravity's constraint may be described as a continuum of strategies ranging from the use of an exo- to an egocentric reference frame for segmental stabilisation. At one extremity, the subjects used systematically an exocentric frame to control each of their body segments independently, as under normogravity conditions. At the other, the segmental stabilisation strategies consist in systematically adopting an egocentric reference frame to control their forearm's stabilisation. A strong correlation between the mode of segmental stabilisation used and the perceptual typology (dependence--independence with respect to the visual field of the subjects was reported. CONCLUSION: The results of this study show different subjects' typologies from those that use the forearm orientation in a mainly exocentric reference frame to

  11. Effects of Uncertainties in Electric Field Boundary Conditions for Ring Current Simulations

    Science.gov (United States)

    Chen, Margaret W.; O'Brien, T. Paul; Lemon, Colby L.; Guild, Timothy B.

    2018-01-01

    Physics-based simulation results can vary widely depending on the applied boundary conditions. As a first step toward assessing the effect of boundary conditions on ring current simulations, we analyze the uncertainty of cross-polar cap potentials (CPCP) on electric field boundary conditions applied to the Rice Convection Model-Equilibrium (RCM-E). The empirical Weimer model of CPCP is chosen as the reference model and Defense Meteorological Satellite Program CPCP measurements as the reference data. Using temporal correlations from a statistical analysis of the "errors" between the reference model and data, we construct a Monte Carlo CPCP discrete time series model that can be generalized to other model boundary conditions. RCM-E simulations using electric field boundary conditions from the reference model and from 20 randomly generated Monte Carlo discrete time series of CPCP are performed for two large storms. During the 10 August 2000 storm main phase, the proton density at 10 RE at midnight was observed to be low (Dst index is bounded by the simulated Dst values. In contrast, the simulated Dst values during the recovery phases of the 10 August 2000 and 31 August 2005 storms tend to underestimate systematically the observed late Dst recovery. This suggests a need to improve the accuracy of particle loss calculations in the RCM-E model. Application of this technique can aid modelers to make efficient choices on either investing more effort on improving specification of boundary conditions or on improving descriptions of physical processes.

  12. Enabling full-field physics-based optical proximity correction via dynamic model generation

    Science.gov (United States)

    Lam, Michael; Clifford, Chris; Raghunathan, Ananthan; Fenger, Germain; Adam, Kostas

    2017-07-01

    As extreme ultraviolet lithography becomes closer to reality for high volume production, its peculiar modeling challenges related to both inter and intrafield effects have necessitated building an optical proximity correction (OPC) infrastructure that operates with field position dependency. Previous state-of-the-art approaches to modeling field dependency used piecewise constant models where static input models are assigned to specific x/y-positions within the field. OPC and simulation could assign the proper static model based on simulation-level placement. However, in the realm of 7 and 5 nm feature sizes, small discontinuities in OPC from piecewise constant model changes can cause unacceptable levels of edge placement errors. The introduction of dynamic model generation (DMG) can be shown to effectively avoid these dislocations by providing unique mask and optical models per simulation region, allowing a near continuum of models through the field. DMG allows unique models for electromagnetic field, apodization, aberrations, etc. to vary through the entire field and provides a capability to precisely and accurately model systematic field signatures.

  13. Environmental Change in Post-closure Safety Assessment of Solid Radioactive Waste Repositories. Report of Working Group 3 Reference Models for Waste Disposal of EMRAS II Topical Heading Reference Approaches for Human Dose Assessment. Environmental Modelling for Radiation Safety (EMRAS II) Programme

    International Nuclear Information System (INIS)

    2016-08-01

    Environmental assessment models are used for evaluating the radiological impact of actual and potential releases of radionuclides to the environment. They are essential tools for use in the regulatory control of routine discharges to the environment and also in planning measures to be taken in the event of accidental releases. They are also used for predicting the impact of releases which may occur far into the future, for example, from underground radioactive waste repositories. It is important to verify, to the extent possible, the reliability of the predictions of such models by a comparison with measured values in the environment or with predictions of other models. The IAEA has been organizing programmes of international model testing since the 1980s. These programmes have contributed to a general improvement in models, in the transfer of data and in the capabilities of modellers in Member States. IAEA publications on this subject over the past three decades demonstrate the comprehensive nature of the programmes and record the associated advances which have been made. From 2009 to 2011, the IAEA organized a programme entitled Environmental Modelling for Radiation Safety (EMRAS II), which concentrated on the improvement of environmental transfer models and the development of reference approaches to estimate the radiological impacts on humans, as well as on flora and fauna, arising from radionuclides in the environment. Different aspects were addressed by nine working groups covering three themes: reference approaches for human dose assessment, reference approaches for biota dose assessment and approaches for assessing emergency situations. This publication describes the work of the Reference Models for Waste Disposal Working Group

  14. Integrated field modelling[Oil and gas fields

    Energy Technology Data Exchange (ETDEWEB)

    Nazarian, Bamshad

    2002-07-01

    This research project studies the feasibility of developing and applying an integrated field simulator to simulate the production performance of an entire oil or gas field. It integrates the performance of the reservoir, the wells, the chokes, the gathering system, the surface processing facilities and whenever applicable, gas and water injection systems. The approach adopted for developing the integrated simulator is to couple existing commercial reservoir and process simulators using available linking technologies. The simulators are dynamically linked and customised into a single hybrid application that benefits from the concept of open software architecture. The integrated field simulator is linked to an optimisation routine developed based on the genetic algorithm search strategies. This enables optimisation of the system at field level, from the reservoir to the process. Modelling the wells and the gathering network is achieved by customising the process simulator. This study demonstrated that the integrated simulation improves current capabilities to simulate the performance of the entire field and optimise its design. This is achieved by evaluating design options including spread and layout of the wells and gathering system, processing alternatives, reservoir development schemes and production strategies. Effectiveness of the integrated simulator is demonstrated and tested through several field-level case studies that discuss and investigate technical problems relevant to offshore field development. The case studies cover topics such as process optimisation, optimum tie-in of satellite wells into existing process facilities, optimal well location and field layout assessment of a high pressure high temperature deepwater oil field. Case study results confirm the viability of the total field simulator by demonstrating that the field performance simulation and optimal design were obtained in an automated process with treasonable computation time. No significant

  15. Full-reference quality assessment of stereoscopic images by learning binocular receptive field properties.

    Science.gov (United States)

    Shao, Feng; Li, Kemeng; Lin, Weisi; Jiang, Gangyi; Yu, Mei; Dai, Qionghai

    2015-10-01

    Quality assessment of 3D images encounters more challenges than its 2D counterparts. Directly applying 2D image quality metrics is not the solution. In this paper, we propose a new full-reference quality assessment for stereoscopic images by learning binocular receptive field properties to be more in line with human visual perception. To be more specific, in the training phase, we learn a multiscale dictionary from the training database, so that the latent structure of images can be represented as a set of basis vectors. In the quality estimation phase, we compute sparse feature similarity index based on the estimated sparse coefficient vectors by considering their phase difference and amplitude difference, and compute global luminance similarity index by considering luminance changes. The final quality score is obtained by incorporating binocular combination based on sparse energy and sparse complexity. Experimental results on five public 3D image quality assessment databases demonstrate that in comparison with the most related existing methods, the devised algorithm achieves high consistency with subjective assessment.

  16. Lectures on matrix field theory

    CERN Document Server

    Ydri, Badis

    2017-01-01

    These lecture notes provide a systematic introduction to matrix models of quantum field theories with non-commutative and fuzzy geometries. The book initially focuses on the matrix formulation of non-commutative and fuzzy spaces, followed by a description of the non-perturbative treatment of the corresponding field theories. As an example, the phase structure of non-commutative phi-four theory is treated in great detail, with a separate chapter on the multitrace approach. The last chapter offers a general introduction to non-commutative gauge theories, while two appendices round out the text. Primarily written as a self-study guide for postgraduate students – with the aim of pedagogically introducing them to key analytical and numerical tools, as well as useful physical models in applications – these lecture notes will also benefit experienced researchers by providing a reference guide to the fundamentals of non-commutative field theory with an emphasis on matrix models and fuzzy geometries.

  17. TESTING MAGNETIC FIELD MODELS FOR THE CLASS 0 PROTOSTAR L1527

    International Nuclear Information System (INIS)

    Davidson, J. A.; Li, Z.-Y.; Hull, C. L. H.; Plambeck, R. L.; Kwon, W.; Crutcher, R. M.; Looney, L. W.; Novak, G.; Chapman, N. L.; Matthews, B. C.; Stephens, I. W.; Tobin, J. J.; Jones, T. J.

    2014-01-01

    For the Class 0 protostar L1527 we compare 131 polarization vectors from SCUPOL/JCMT, SHARP/CSO, and TADPOL/CARMA observations with the corresponding model polarization vectors of four ideal-MHD, nonturbulent, cloud core collapse models. These four models differ by their initial magnetic fields before collapse; two initially have aligned fields (strong and weak) and two initially have orthogonal fields (strong and weak) with respect to the rotation axis of the L1527 core. Only the initial weak orthogonal field model produces the observed circumstellar disk within L1527. This is a characteristic of nearly all ideal-MHD, nonturbulent, core collapse models. In this paper we test whether this weak orthogonal model also has the best agreement between its magnetic field structure and that inferred from the polarimetry observations of L1527. We found that this is not the case; based on the polarimetry observations, the most favored model of the four is the weak aligned model. However, this model does not produce a circumstellar disk, so our result implies that a nonturbulent, ideal-MHD global collapse model probably does not represent the core collapse that has occurred in L1527. Our study also illustrates the importance of using polarization vectors covering a large area of a cloud core to determine the initial magnetic field orientation before collapse; the inner core magnetic field structure can be highly altered by a collapse, and so measurements from this region alone can give unreliable estimates of the initial field configuration before collapse

  18. TESTING MAGNETIC FIELD MODELS FOR THE CLASS 0 PROTOSTAR L1527

    Energy Technology Data Exchange (ETDEWEB)

    Davidson, J. A. [University of Western Australia, School of Physics, 35 Stirling Highway, Crawley, WA 6009 (Australia); Li, Z.-Y. [Astronomy Department, University of Virginia, Charlottesville, VA 22904 (United States); Hull, C. L. H.; Plambeck, R. L. [Astronomy Department and Radio Astronomy Laboratory, University of California, Berkeley, CA 94720-3411 (United States); Kwon, W. [SRON Netherlands Institute for Space Research, Landleven 12, 9747 AD, Groningen (Netherlands); Crutcher, R. M.; Looney, L. W. [Department of Astronomy, University of Illinois, 1002 West Green Street, Urbana, IL 61801 (United States); Novak, G.; Chapman, N. L. [Northwestern University, Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and the Department of Physics and Astronomy, 2145 Sheridan Road, Evanston, IL 60208 (United States); Matthews, B. C. [Herzberg Astronomy and Astrophysics, National Research Council of Canada, 5071 West Saanich Road, Victoria, BC, V9E 2E7 (Canada); Stephens, I. W. [Boston University, Institute for Astrophysical Research, Boston, MA 02215 (United States); Tobin, J. J. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Jones, T. J., E-mail: jackie.davidson@uwa.edu.au [University of Minnesota, 116 Church Street SE, Minneapolis, MN 55455 (United States)

    2014-12-20

    For the Class 0 protostar L1527 we compare 131 polarization vectors from SCUPOL/JCMT, SHARP/CSO, and TADPOL/CARMA observations with the corresponding model polarization vectors of four ideal-MHD, nonturbulent, cloud core collapse models. These four models differ by their initial magnetic fields before collapse; two initially have aligned fields (strong and weak) and two initially have orthogonal fields (strong and weak) with respect to the rotation axis of the L1527 core. Only the initial weak orthogonal field model produces the observed circumstellar disk within L1527. This is a characteristic of nearly all ideal-MHD, nonturbulent, core collapse models. In this paper we test whether this weak orthogonal model also has the best agreement between its magnetic field structure and that inferred from the polarimetry observations of L1527. We found that this is not the case; based on the polarimetry observations, the most favored model of the four is the weak aligned model. However, this model does not produce a circumstellar disk, so our result implies that a nonturbulent, ideal-MHD global collapse model probably does not represent the core collapse that has occurred in L1527. Our study also illustrates the importance of using polarization vectors covering a large area of a cloud core to determine the initial magnetic field orientation before collapse; the inner core magnetic field structure can be highly altered by a collapse, and so measurements from this region alone can give unreliable estimates of the initial field configuration before collapse.

  19. Conformal field theories, Coulomb gas picture and integrable models

    International Nuclear Information System (INIS)

    Zuber, J.B.

    1988-01-01

    The aim of the study is to present the links between some results of conformal field theory, the conventional Coulomb gas picture in statistical mechanics and the approach of integrable models. It is shown that families of conformal theories, related by the coset construction to the SU(2) Kac-Moody algebra, may be regarded as obtained from some free field, and modified by the coupling of its winding numbers to floating charges. This representation reflects the procedure of restriction of the corresponding integrable lattice models. The work may be generalized to models based on the coset construction with higher rank algebras. The corresponding integrable models are identified. In the conformal field description, generalized parafermions appear, and are coupled to free fields living on a higher-dimensional torus. The analysis is not as exhaustive as in the SU(2) case: all the various restrictions have not been identified, nor the modular invariants completely classified

  20. Hybrid pregnant reference phantom series based on adult female ICRP reference phantom

    Science.gov (United States)

    Rafat-Motavalli, Laleh; Miri-Hakimabad, Hashem; Hoseinian-Azghadi, Elie

    2018-03-01

    This paper presents boundary representation (BREP) models of pregnant female and her fetus at the end of each trimester. The International Commission on Radiological Protection (ICRP) female reference voxel phantom was used as a base template in development process of the pregnant hybrid phantom series. The differences in shape and location of the displaced maternal organs caused by enlarging uterus were also taken into account. The CT and MR images of fetus specimens and pregnant patients of various ages were used to replace the maternal abdominal pelvic organs of template phantom and insert the fetus inside the gravid uterus. Each fetal model contains 21 different organs and tissues. The skeletal model of the fetus also includes age-dependent cartilaginous and ossified skeletal components. The replaced maternal organ models were converted to NURBS surfaces and then modified to conform to reference values of ICRP Publication 89. The particular feature of current series compared to the previously developed pregnant phantoms is being constructed upon the basis of ICRP reference phantom. The maternal replaced organ models are NURBS surfaces. With this great potential, they might have the feasibility of being converted to high quality polygon mesh phantoms.

  1. Shannon information of the geomagnetic field for the past 7000 years

    OpenAIRE

    De Santis, A.; Qamili, E.

    2010-01-01

    The present behaviour of the geomagnetic field as expressed by the International Geomagnetic Reference Field (IGRF) deserves special attention when compared with that shown over the past few thousands of years by two paleomagnetic/archeomagnetic models, CALS3K and CALS7K. The application of the Information theory in terms of Shannon Information and K-entropy to these models shows characteristics of an instable geomagnetic field. Although the result is mitigated when we correct the CALS7K mode...

  2. Application of the weighted total field-scattering field technique to 3D-PSTD light scattering model

    Science.gov (United States)

    Hu, Shuai; Gao, Taichang; Liu, Lei; Li, Hao; Chen, Ming; Yang, Bo

    2018-04-01

    PSTD (Pseudo Spectral Time Domain) is an excellent model for the light scattering simulation of nonspherical aerosol particles. However, due to the particularity of its discretization form of the Maxwell's equations, the traditional Total Field/Scattering Field (TF/SF) technique for FDTD (Finite Differential Time Domain) is not applicable to PSTD, and the time-consuming pure scattering field technique is mainly applied to introduce the incident wave. To this end, the weighted TF/SF technique proposed by X. Gao is generalized and applied to the 3D-PSTD scattering model. Using this technique, the incident light can be effectively introduced by modifying the electromagnetic components in an inserted connecting region between the total field and the scattering field region with incident terms, where the incident terms are obtained by weighting the incident field by a window function. To optimally determine the thickness of connection region and the window function type for PSTD calculations, their influence on the modeling accuracy is firstly analyzed. To further verify the effectiveness and advantages of the weighted TF/SF technique, the improved PSTD model is validated against the PSTD model equipped with pure scattering field technique in both calculation accuracy and efficiency. The results show that, the performance of PSTD seems to be not sensitive to variation of window functions. The number of the connection layer required decreases with the increasing of spatial resolution, where for spatial resolution of 24 grids per wavelength, a 6-layer region is thick enough. The scattering phase matrices and integral scattering parameters obtained by the improved PSTD show an excellent consistency with those well-tested models for spherical and nonspherical particles, illustrating that the weighted TF/SF technique can introduce the incident precisely. The weighted TF/SF technique shows higher computational efficiency than pure scattering technique.

  3. Simplified realistic human head model for simulating Tumor Treating Fields (TTFields).

    Science.gov (United States)

    Wenger, Cornelia; Bomzon, Ze'ev; Salvador, Ricardo; Basser, Peter J; Miranda, Pedro C

    2016-08-01

    Tumor Treating Fields (TTFields) are alternating electric fields in the intermediate frequency range (100-300 kHz) of low-intensity (1-3 V/cm). TTFields are an anti-mitotic treatment against solid tumors, which are approved for Glioblastoma Multiforme (GBM) patients. These electric fields are induced non-invasively by transducer arrays placed directly on the patient's scalp. Cell culture experiments showed that treatment efficacy is dependent on the induced field intensity. In clinical practice, a software called NovoTalTM uses head measurements to estimate the optimal array placement to maximize the electric field delivery to the tumor. Computational studies predict an increase in the tumor's electric field strength when adapting transducer arrays to its location. Ideally, a personalized head model could be created for each patient, to calculate the electric field distribution for the specific situation. Thus, the optimal transducer layout could be inferred from field calculation rather than distance measurements. Nonetheless, creating realistic head models of patients is time-consuming and often needs user interaction, because automated image segmentation is prone to failure. This study presents a first approach to creating simplified head models consisting of convex hulls of the tissue layers. The model is able to account for anisotropic conductivity in the cortical tissues by using a tensor representation estimated from Diffusion Tensor Imaging. The induced electric field distribution is compared in the simplified and realistic head models. The average field intensities in the brain and tumor are generally slightly higher in the realistic head model, with a maximal ratio of 114% for a simplified model with reasonable layer thicknesses. Thus, the present pipeline is a fast and efficient means towards personalized head models with less complexity involved in characterizing tissue interfaces, while enabling accurate predictions of electric field distribution.

  4. Large field of view quantitative phase imaging of induced pluripotent stem cells and optical pathlength reference materials

    Science.gov (United States)

    Kwee, Edward; Peterson, Alexander; Stinson, Jeffrey; Halter, Michael; Yu, Liya; Majurski, Michael; Chalfoun, Joe; Bajcsy, Peter; Elliott, John

    2018-02-01

    Induced pluripotent stem cells (iPSCs) are reprogrammed cells that can have heterogeneous biological potential. Quality assurance metrics of reprogrammed iPSCs will be critical to ensure reliable use in cell therapies and personalized diagnostic tests. We present a quantitative phase imaging (QPI) workflow which includes acquisition, processing, and stitching multiple adjacent image tiles across a large field of view (LFOV) of a culture vessel. Low magnification image tiles (10x) were acquired with a Phasics SID4BIO camera on a Zeiss microscope. iPSC cultures were maintained using a custom stage incubator on an automated stage. We implement an image acquisition strategy that compensates for non-flat illumination wavefronts to enable imaging of an entire well plate, including the meniscus region normally obscured in Zernike phase contrast imaging. Polynomial fitting and background mode correction was implemented to enable comparability and stitching between multiple tiles. LFOV imaging of reference materials indicated that image acquisition and processing strategies did not affect quantitative phase measurements across the LFOV. Analysis of iPSC colony images demonstrated mass doubling time was significantly different than area doubling time. These measurements were benchmarked with prototype microsphere beads and etched-glass gratings with specified spatial dimensions designed to be QPI reference materials with optical pathlength shifts suitable for cell microscopy. This QPI workflow and the use of reference materials can provide non-destructive traceable imaging method for novel iPSC heterogeneity characterization.

  5. Locating and parsing bibliographic references in HTML medical articles.

    Science.gov (United States)

    Zou, Jie; Le, Daniel; Thoma, George R

    2010-06-01

    The set of references that typically appear toward the end of journal articles is sometimes, though not always, a field in bibliographic (citation) databases. But even if references do not constitute such a field, they can be useful as a preprocessing step in the automated extraction of other bibliographic data from articles, as well as in computer-assisted indexing of articles. Automation in data extraction and indexing to minimize human labor is key to the affordable creation and maintenance of large bibliographic databases. Extracting the components of references, such as author names, article title, journal name, publication date and other entities, is therefore a valuable and sometimes necessary task. This paper describes a two-step process using statistical machine learning algorithms, to first locate the references in HTML medical articles and then to parse them. Reference locating identifies the reference section in an article and then decomposes it into individual references. We formulate this step as a two-class classification problem based on text and geometric features. An evaluation conducted on 500 articles drawn from 100 medical journals achieves near-perfect precision and recall rates for locating references. Reference parsing identifies the components of each reference. For this second step, we implement and compare two algorithms. One relies on sequence statistics and trains a Conditional Random Field. The other focuses on local feature statistics and trains a Support Vector Machine to classify each individual word, followed by a search algorithm that systematically corrects low confidence labels if the label sequence violates a set of predefined rules. The overall performance of these two reference-parsing algorithms is about the same: above 99% accuracy at the word level, and over 97% accuracy at the chunk level.

  6. Normal gravity field in relativistic geodesy

    Science.gov (United States)

    Kopeikin, Sergei; Vlasov, Igor; Han, Wen-Biao

    2018-02-01

    Modern geodesy is subject to a dramatic change from the Newtonian paradigm to Einstein's theory of general relativity. This is motivated by the ongoing advance in development of quantum sensors for applications in geodesy including quantum gravimeters and gradientometers, atomic clocks and fiber optics for making ultra-precise measurements of the geoid and multipolar structure of the Earth's gravitational field. At the same time, very long baseline interferometry, satellite laser ranging, and global navigation satellite systems have achieved an unprecedented level of accuracy in measuring 3-d coordinates of the reference points of the International Terrestrial Reference Frame and the world height system. The main geodetic reference standard to which gravimetric measurements of the of Earth's gravitational field are referred is a normal gravity field represented in the Newtonian gravity by the field of a uniformly rotating, homogeneous Maclaurin ellipsoid of which mass and quadrupole momentum are equal to the total mass and (tide-free) quadrupole moment of Earth's gravitational field. The present paper extends the concept of the normal gravity field from the Newtonian theory to the realm of general relativity. We focus our attention on the calculation of the post-Newtonian approximation of the normal field that is sufficient for current and near-future practical applications. We show that in general relativity the level surface of homogeneous and uniformly rotating fluid is no longer described by the Maclaurin ellipsoid in the most general case but represents an axisymmetric spheroid of the fourth order with respect to the geodetic Cartesian coordinates. At the same time, admitting a post-Newtonian inhomogeneity of the mass density in the form of concentric elliptical shells allows one to preserve the level surface of the fluid as an exact ellipsoid of rotation. We parametrize the mass density distribution and the level surface with two parameters which are

  7. Pharmacological evaluation of NSAID-induced gastropathy as a "Translatable" model of referred visceral hypersensitivity.

    Science.gov (United States)

    Hummel, Michele; Knappenberger, Terri; Reilly, Meghan; Whiteside, Garth T

    2017-09-07

    To evaluate whether non-steroidal anti-inflammatory drugs (NSAIDs)-induced gastropathy is a clinically predictive model of referred visceral hypersensitivity. Gastric ulcer pain was induced by the oral administration of indomethacin to male, CD1 mice ( n = 10/group) and then assessed by measuring referred abdominal hypersensitivity to tactile application. A diverse range of pharmacological mechanisms contributing to the pain were subsequently investigated. These mechanisms included: transient receptor potential (TRP), sodium and acid-sensing ion channels (ASICs) as well as opioid receptors and guanylate cyclase C (GC-C). Results showed that two opioids and a GC-C agonist, morphine, asimadoline and linaclotide, respectively, the TRP antagonists, AMG9810 and HC-030031 and the sodium channel blocker, carbamazepine, elicited a dose- and/or time-dependent attenuation of referred visceral hypersensitivity, while the ASIC blocker, amiloride, was ineffective at all doses tested. Together, these findings implicate opioid receptors, GC-C, and sodium and TRP channel activation as possible mechanisms associated with visceral hypersensitivity. More importantly, these findings also validate NSAID-induced gastropathy as a sensitive and clinically predictive mouse model suitable for assessing novel molecules with potential pain-attenuating properties.

  8. Preliminary validation of a Monte Carlo model for IMRT fields

    International Nuclear Information System (INIS)

    Wright, Tracy; Lye, Jessica; Mohammadi, Mohammad

    2011-01-01

    Full text: A Monte Carlo model of an Elekta linac, validated for medium to large (10-30 cm) symmetric fields, has been investigated for small, irregular and asymmetric fields suitable for IMRT treatments. The model has been validated with field segments using radiochromic film in solid water. The modelled positions of the multileaf collimator (MLC) leaves have been validated using EBT film, In the model, electrons with a narrow energy spectrum are incident on the target and all components of the linac head are included. The MLC is modelled using the EGSnrc MLCE component module. For the validation, a number of single complex IMRT segments with dimensions approximately 1-8 cm were delivered to film in solid water (see Fig, I), The same segments were modelled using EGSnrc by adjusting the MLC leaf positions in the model validated for 10 cm symmetric fields. Dose distributions along the centre of each MLC leaf as determined by both methods were compared. A picket fence test was also performed to confirm the MLC leaf positions. 95% of the points in the modelled dose distribution along the leaf axis agree with the film measurement to within 1%/1 mm for dose difference and distance to agreement. Areas of most deviation occur in the penumbra region. A system has been developed to calculate the MLC leaf positions in the model for any planned field size.

  9. A model reference and sensitivity model-based self-learning fuzzy logic controller as a solution for control of nonlinear servo systems

    NARCIS (Netherlands)

    Kovacic, Z.; Bogdan, S.; Balenovic, M.

    1999-01-01

    In this paper, the design, simulation and experimental verification of a self-learning fuzzy logic controller (SLFLC) suitable for the control of nonlinear servo systems are described. The SLFLC contains a learning algorithm that utilizes a second-order reference model and a sensitivity model

  10. Two Populations Mean-Field Monomer-Dimer Model

    Science.gov (United States)

    Alberici, Diego; Mingione, Emanuele

    2018-04-01

    A two populations mean-field monomer-dimer model including both hard-core and attractive interactions between dimers is considered. The pressure density in the thermodynamic limit is proved to satisfy a variational principle. A detailed analysis is made in the limit of one population is much smaller than the other and a ferromagnetic mean-field phase transition is found.

  11. Application of an electronic bulletin board, as a mechanism of coordination of actions in complex systems - reference model

    Directory of Open Access Journals (Sweden)

    Katarzyna Grzybowska

    2015-06-01

    Full Text Available Background: In her previous research, the author of this publication indicates that coordination is a dependent variable which has a great driving force and is a very unstable factor. This results in the fact that all of the actions connected with coordination have an impact on other factors of cooperation as well as the integration of the enterprises in the structures of a supply chain type structure. Material and methods:  The article has been divided into two basic parts. The first part regards the reference models in complex systems (supply chain systems. They can constitute a starting point for the modelling of target processes in the built supply chain structure. The second part presents template process models (Reference Models for selected action coordination mechanisms during enterprise cooperation. The aim of the article is the presentation the model an Electronic Bulletin Board (EBB, as a mechanism of coordination of actions in complex systems. Results: The article was prepared on the basis of literature from the researched area. The material was also prepared on the basis of interviews with practitioners. They have allowed for the preparation of template process models (Reference Models for selected action coordination methods in the supply chain. Conclusions: The result of the work is a prepared model as well as its description in the use of IDEF0. The presented model is a demonstrative model. The proposed reference model makes it possible to define the parameters of a selected mechanism of coordination of actions, and forms a basis for affecting the progression of the process through an analysis of values of identified parameters. The parameterization of elements constitutes the foundation for the monitoring of the process via 1 unambiguous identification of the object of monitoring and 2 analysis of different variants of the progression of the process.

  12. Some variations of the Kristallin-I near-field model

    Energy Technology Data Exchange (ETDEWEB)

    Smith, P A; Curti, E [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1995-11-01

    The Kristallin-I project is an integrated analysis of the final disposal of vitrified high-level radioactive waste (HLW) in the crystalline basement of Northern Switzerland. It includes an analysis of the radiological consequences of radionuclide release from a repository. This analysis employs a chain of independent models for the near-field, geosphere and biosphere. In constructing these models, processes are incorporated that are believed to be relevant to repository safety, while other processes are neglected. In the present report, a set of simplified, steady-state models of the near-field is developed to investigate the possible effects of specific processes which are neglected in the time-dependent Kristallin-I near-field model. These processes are neglected, either because (i) they are thought unlikely to occur to a significant degree, or because (ii) they are likely to make a positive contribution to the performance of the near-field barrier to radionuclide migration, but are insufficiently understood to justify incorporating them in a safety assessment. The aim of this report is to investigate whether the arguments for neglecting these processes in the Kristallin-I near-field model can be justified. This work addresses the following topics: - radionuclide transport at the bentonite-host rock interface, - canister settlement, -chemical conditions and radionuclide transport at the glass-bentonite interface. (author) figs., tabs., refs.

  13. Some variations of the Kristallin-I near-field model

    International Nuclear Information System (INIS)

    Smith, P.A.; Curti, E.

    1995-11-01

    The Kristallin-I project is an integrated analysis of the final disposal of vitrified high-level radioactive waste (HLW) in the crystalline basement of Northern Switzerland. It includes an analysis of the radiological consequences of radionuclide release from a repository. This analysis employs a chain of independent models for the near-field, geosphere and biosphere. In constructing these models, processes are incorporated that are believed to be relevant to repository safety, while other processes are neglected. In the present report, a set of simplified, steady-state models of the near-field is developed to investigate the possible effects of specific processes which are neglected in the time-dependent Kristallin-I near-field model. These processes are neglected, either because (i) they are thought unlikely to occur to a significant degree, or because (ii) they are likely to make a positive contribution to the performance of the near-field barrier to radionuclide migration, but are insufficiently understood to justify incorporating them in a safety assessment. The aim of this report is to investigate whether the arguments for neglecting these processes in the Kristallin-I near-field model can be justified. This work addresses the following topics: - radionuclide transport at the bentonite-host rock interface, - canister settlement, -chemical conditions and radionuclide transport at the glass-bentonite interface. (author) figs., tabs., refs

  14. A stochastic phase-field model determined from molecular dynamics

    KAUST Repository

    von Schwerin, Erik

    2010-03-17

    The dynamics of dendritic growth of a crystal in an undercooled melt is determined by macroscopic diffusion-convection of heat and by capillary forces acting on the nanometer scale of the solid-liquid interface width. Its modelling is useful for instance in processing techniques based on casting. The phase-field method is widely used to study evolution of such microstructural phase transformations on a continuum level; it couples the energy equation to a phenomenological Allen-Cahn/Ginzburg-Landau equation modelling the dynamics of an order parameter determining the solid and liquid phases, including also stochastic fluctuations to obtain the qualitatively correct result of dendritic side branching. This work presents a method to determine stochastic phase-field models from atomistic formulations by coarse-graining molecular dynamics. It has three steps: (1) a precise quantitative atomistic definition of the phase-field variable, based on the local potential energy; (2) derivation of its coarse-grained dynamics model, from microscopic Smoluchowski molecular dynamics (that is Brownian or over damped Langevin dynamics); and (3) numerical computation of the coarse-grained model functions. The coarse-grained model approximates Gibbs ensemble averages of the atomistic phase-field, by choosing coarse-grained drift and diffusion functions that minimize the approximation error of observables in this ensemble average. © EDP Sciences, SMAI, 2010.

  15. A stochastic phase-field model determined from molecular dynamics

    KAUST Repository

    von Schwerin, Erik; Szepessy, Anders

    2010-01-01

    The dynamics of dendritic growth of a crystal in an undercooled melt is determined by macroscopic diffusion-convection of heat and by capillary forces acting on the nanometer scale of the solid-liquid interface width. Its modelling is useful for instance in processing techniques based on casting. The phase-field method is widely used to study evolution of such microstructural phase transformations on a continuum level; it couples the energy equation to a phenomenological Allen-Cahn/Ginzburg-Landau equation modelling the dynamics of an order parameter determining the solid and liquid phases, including also stochastic fluctuations to obtain the qualitatively correct result of dendritic side branching. This work presents a method to determine stochastic phase-field models from atomistic formulations by coarse-graining molecular dynamics. It has three steps: (1) a precise quantitative atomistic definition of the phase-field variable, based on the local potential energy; (2) derivation of its coarse-grained dynamics model, from microscopic Smoluchowski molecular dynamics (that is Brownian or over damped Langevin dynamics); and (3) numerical computation of the coarse-grained model functions. The coarse-grained model approximates Gibbs ensemble averages of the atomistic phase-field, by choosing coarse-grained drift and diffusion functions that minimize the approximation error of observables in this ensemble average. © EDP Sciences, SMAI, 2010.

  16. Models of Reference Services in Australian Academic Libraries

    Science.gov (United States)

    Burke, Liz

    2008-01-01

    This article reports on a project which was undertaken in 2006 to investigate the current modes and methods for delivering reference services in Australian academic libraries. The project included a literature review to assist in providing a definition of reference services as well as a snapshot of statistics showing staff and patron numbers from…

  17. Historical sketches of Sandia National Laboratories nuclear field testing. Volume 1: Full discussion except for sensitive references

    International Nuclear Information System (INIS)

    Banister, J.R.

    1994-10-01

    This report contains historical sketches that cover the major activities of Sandia nuclear field testing, from early atmospheric shots until 1990. It includes a chronological overview followed by more complete discussions of atmospheric, high-altitude, underwater, cratering, and underground nuclear testing. Other activities related to nuclear testing and high-explosive tests are also described. A large number of references are cited for readers who wish to learn more about technical details. Appendices, written by several authors, provide more insight for a variety of special aspects of nuclear testing and related work. Two versions of this history were published: volume 1 has an unlimited distribution, and volume 2 has a limited distribution

  18. EIA model documentation: World oil refining logistics demand model,``WORLD`` reference manual. Version 1.1

    Energy Technology Data Exchange (ETDEWEB)

    1994-04-11

    This manual is intended primarily for use as a reference by analysts applying the WORLD model to regional studies. It also provides overview information on WORLD features of potential interest to managers and analysts. Broadly, the manual covers WORLD model features in progressively increasing detail. Section 2 provides an overview of the WORLD model, how it has evolved, what its design goals are, what it produces, and where it can be taken with further enhancements. Section 3 reviews model management covering data sources, managing over-optimization, calibration and seasonality, check-points for case construction and common errors. Section 4 describes in detail the WORLD system, including: data and program systems in overview; details of mainframe and PC program control and files;model generation, size management, debugging and error analysis; use with different optimizers; and reporting and results analysis. Section 5 provides a detailed description of every WORLD model data table, covering model controls, case and technology data. Section 6 goes into the details of WORLD matrix structure. It provides an overview, describes how regional definitions are controlled and defines the naming conventions for-all model rows, columns, right-hand sides, and bounds. It also includes a discussion of the formulation of product blending and specifications in WORLD. Several Appendices supplement the main sections.

  19. A model unified field equation

    International Nuclear Information System (INIS)

    Perring, J.K.; Skyrme, T.H.R.

    1994-01-01

    The classical solutions of a unified field theory in a two-dimensional space-time are considered. This system, a model of a interacting mesons and baryons, illustrates how the particle can be built from a wave-packet of mesons and how reciprocally the meson appears as a tightly bound combination of particle and antiparticle. (author). 6 refs

  20. Perl/Tk Pocket Reference

    CERN Document Server

    Lidie, Stephen

    1998-01-01

    The Perl/Tk Pocket Reference is a companion volume to Learning Perl/Tk, an O'Reilly Animal Guide. Learning Perl/Tk is a tutorial for Perl/Tk, the extension to Perl for creating graphical user interfaces. With Tk, Perl programs can be window-based rather than command-line based, with buttons, entry fields, listboxes, menus, scrollbars, balloons, tables, dialogs, and more. And Perl/Tk programs run on UNIX and Windows-based computers. This small book is a handy reference guide geared toward the advanced Perl/Tk programmer. Novice Perl/Tk programmers will find that its compact size gives th

  1. Measurement and modeling of polarized specular neutron reflectivity in large magnetic fields.

    Science.gov (United States)

    Maranville, Brian B; Kirby, Brian J; Grutter, Alexander J; Kienzle, Paul A; Majkrzak, Charles F; Liu, Yaohua; Dennis, Cindi L

    2016-08-01

    The presence of a large applied magnetic field removes the degeneracy of the vacuum energy states for spin-up and spin-down neutrons. For polarized neutron reflectometry, this must be included in the reference potential energy of the Schrödinger equation that is used to calculate the expected scattering from a magnetic layered structure. For samples with magnetization that is purely parallel or antiparallel to the applied field which defines the quantization axis, there is no mixing of the spin states (no spin-flip scattering) and so this additional potential is constant throughout the scattering region. When there is non-collinear magnetization in the sample, however, there will be significant scattering from one spin state into the other, and the reference potentials will differ between the incoming and outgoing wavefunctions, changing the angle and intensities of the scattering. The theory of the scattering and recommended experimental practices for this type of measurement are presented, as well as an example measurement.

  2. Three-field modeling with droplet entrainment and de-entrainment models for TRAC-M

    International Nuclear Information System (INIS)

    Lee, Sang Ik

    2005-02-01

    A three-field modeling has been developed and implemented to the basic one-dimensional components of TRAC-M/F90 (Modernized Transient Reactor Analysis Code, Fortran90) to improve the estimation of the behavior of droplet entrainment. the divide and conquer algorithmic technique is adjusted for the implementation after considering the verifications. The governing equations are composed of the conservation equations of each field with thermal-equilibrium assumption between the two liquid fields. As a result, three momentum equations, four mass equations including noncondensable gas mass equation and two energy equations are used. In the development of the momentum equation for an entrained droplet, two different kinds of approaches are tested: the simple force balance on a single droplet and the field-type equation based on the continuum assumption. The first showed unstable nature and the latter was chosen. All of the necessary empirical correlations were obtained from literatures, in particular, the physical models of COBRA-TF. The sensitivities of each empirical correlation were investigated where the effect of droplet diameter and droplet drag was found to be negligible. The advantages of the SETS numerical scheme in comparison with the semi-implicit nimerical scheme were addressed in the simulation time and the maximum allowed time-step size. Finally, the simulations of Collier and Hewitt's experiment were performed and it is concluded that the three-field model developed in the present study is reasonable. The predictions by the present code agree with the measured values within the RMS errors of 16.5% and 9.6% in the entrained liquid mass flow rates and the pressure gradients, respectively. Assessment on the physical models is performed. The wall and interfacial drag models were determined at first. After that, the assessments of entrainment model were performed. Wurtz's entrainment model, which was used in COBRA-TF and Kataoka and Ishii's model, were mainly

  3. Measurement of the Constructs of Health Belief Model related to Self-care during Pregnancy in Women Referred to South Tehran Health Network

    Directory of Open Access Journals (Sweden)

    Yalda Soleiman Ekhtiari

    2016-03-01

    Full Text Available Background and Objective: Self-care activities during pregnancy can be effective in reducing adverse pregnancy outcomes. Health Belief Model (HBM is one of the most applicable models in educational need assessment for planning and implementation of educational interventions. The purpose of this study was to measurement of the constructs of HBM related to self-care during pregnancy in women referred to South Tehran health network.Materials and Methods: In this cross-sectional study 270 pregnant women who referred to health centers of South Tehran Health Networks participated. Demographic, knowledge and attitude questionnaires based on constructs of HBM was used to measure the status of knowledge and attitude of women. Data were analyzed using statistical software SPSS18.Results: Results showed that 92.2% of women had the knowledge scores in good level. The scores of perceived severity, perceived self-efficacy and cues to action were in good level in almost of women but almost of women obtained weak point in perceived susceptibility, perceived benefits and barriersConclusion: HBM can be used as an appropriate tool for assessment the status of pregnant women in the field of self-care behaviors during pregnancy and planning and implementation of educational interventions.

  4. Three-dimensional model of reference thermal/mechanical and hydrological stratigraphy at Yucca Mountain, southern Nevada

    International Nuclear Information System (INIS)

    Ortiz, T.S.; Williams, R.L.; Nimick, F.B.; Whittet, B.C.; South, D.L.

    1985-10-01

    The Nevada Nuclear Waste Storage Investigations (NNWSI) project is currently examining the feasibility of constructing a nuclear waste repository in the tuffs beneath Yucca Mountain. A three-dimensional model of the thermal/mechanical and hydrological reference stratigraphy at Yucca Mountain has been developed for use in performance assessment and repository design studies involving material properties data. The reference stratigraphy defines units with distinct thermal, physical, mechanical, and hydrological properties. The model is a collection of surface representations, each surface representing the base of a particular unit. The reliability of the model was evaluated by comparing the generated surfaces, existing geologic maps and cross sections, drill hole data, and geologic interpolation. Interpolation of surfaces between drill holes by the model closely matches the existing information. The top of a zone containing prevalent zeolite is defined and superimposed on the reference stratigraphy. Interpretation of the geometric relations between the zeolitic and thermal/mechanical and hydrological surfaces indicates that the zeolitic zone was established before the major portion of local fault displacement took place; however, faulting and zeolitization may have been partly concurrent. The thickness of the proposed repository host rock, the devitrified, relatively lithophysal-poor, moderately to densely welded portion of the Topopah Spring Member of the Paintbrush Tuff, was evaluated and varies from 400 to 800 ft in the repository area. The distance from the repository to groundwater level was estimated to vary from 700 to 1400 ft. 13 figs., 1 tab

  5. Reference crop evapotranspiration estimate using high-resolution meteorological network's data

    Directory of Open Access Journals (Sweden)

    C. Lussana

    2009-10-01

    Full Text Available Water management authorities need detailed information about each component of the hydrological balance. This document presents a method to estimate the evapotranspiration rate, initialized in order to obtain the reference crop evapotranspiration rate (ET0. By using an Optimal Interpolation (OI scheme, the hourly observations of several meteorological variables, measured by a high-resolution local meteorological network, are interpolated over a regular grid. The analysed meteorological fields, containing detailed meteorological information, enter a model for turbulent heat fluxes estimation based on Monin-Obukhov surface layer similarity theory. The obtained ET0 fields are then post-processed and disseminated to the users.

  6. Safety Assessment for LILW Near-Surface Disposal Facility Using the IAEA Reference Model and MASCOT Program

    International Nuclear Information System (INIS)

    Kim, Hyun Joo; Park, Joo Wan; Kim, Chang Lak

    2002-01-01

    A reference scenario of vault safety case prepared by the IAEA for the near-surface disposal facility of low-and intermediate-level radioactive wastes is assessed with the MASCOT program. The appropriate conceptual models for the MASCOT implementation is developed. An assessment of groundwater pathway through a drinking well as a geosphere-biosphere interface is performed first, then biosphere pathway is analysed to estimate the radiological consequences of the disposed radionuclides based on compartment modeling approach. The validity of conceptual modeling for the reference scenario is investigated where possible comparing to the results generated by the other assessment. The result of this study shows that the typical conceptual model for groundwater pathway represented by the compartment model can be satisfactorily used for safety assessment of the entire disposal system in a consistent way. It is also shown that safety assessment of a disposal facility considering complex and various pathways would be possible by the MASCOT program

  7. H+3 WZNW model from Liouville field theory

    International Nuclear Information System (INIS)

    Hikida, Y.; Schomerus, V.

    2007-06-01

    There exists an intriguing relation between genus zero correlation functions in the H + 3 WZNW model and in Liouville field theory. This was found by Ribault and Teschner based in part on earlier ideas by Stoyanovsky. We provide a path integral derivation of the correspondence and then use our new approach to generalize the relation to surfaces of arbitrary genus g. In particular we determine the correlation functions of N primary fields in the WZNW model explicitly through Liouville correlators with N+2g-2 additional insertions of certain degenerate fields. The paper concludes with a list of interesting further extensions and a few comments on the relation to the geometric Langlands program. (orig.)

  8. Antiferromagnetic Ising model with transverse and longitudinal field

    International Nuclear Information System (INIS)

    Kischinhevsky, M.

    1985-01-01

    We study the quantum hamiltonian version of the Ising Model in one spacial dimension under an external longitudinal (uniform) field at zero temperature. A phenomenological renormalization group procedure is used to obtain the phase diagram; the transverse and longitudinal zero field limits are studied and we verify the validity of universality at non zero transverse fields, where two-dimensional critical behaviour is obtained. To perform the numerical calculations we use the Lanczos scheme, which gives highly precise results with rather short processing times. We also analyse the possibility of using these techniques to extend the present work to the quantum hamiltonian version of the q-state Potts Model (q>2) in larger system. (author) [pt

  9. Genesis of unified models from Majorana-Weyl fields

    International Nuclear Information System (INIS)

    Budini, P.; Furlan, P.

    1977-07-01

    It is proposed that all forms of interaction arise from elementary interactions between Weyl-Majorana fields. Weak interactions due to the high masses of the intermediate bosons are practically identical to the elementary interactions. Strong and electromagnetic interactions arise at larger distance, where dynamic determines both masses and symmetry. In the frame of these ideas, Pati-Salam and Fritzsch-Minkowski type of unified models are constructed starting from eight Weyl-Majorana fields. Fractional charges for quarks, integer charges for lepton and regularization of q.e.d. arise naturally from the model. Unobserved transitions (μ→e + γ, p→ leptons) may be ascribed to properties of the elementary fields (handedness) rather than very high W masses

  10. A methodology and supply chain management inspired reference ontology for modeling healthcare teams.

    Science.gov (United States)

    Kuziemsky, Craig E; Yazdi, Sara

    2011-01-01

    Numerous studies and strategic plans are advocating more team based healthcare delivery that is facilitated by information and communication technologies (ICTs). However before we can design ICTs to support teams we need a solid conceptual model of team processes and a methodology for using such a model in healthcare settings. This paper draws upon success in the supply chain management domain to develop a reference ontology of healthcare teams and a methodology for modeling teams to instantiate the ontology in specific settings. This research can help us understand how teams function and how we can design ICTs to support teams.

  11. Model parameter uncertainty analysis for annual field-scale P loss model

    Science.gov (United States)

    Phosphorous (P) loss models are important tools for developing and evaluating conservation practices aimed at reducing P losses from agricultural fields. All P loss models, however, have an inherent amount of uncertainty associated with them. In this study, we conducted an uncertainty analysis with ...

  12. Health-related physical fitness measures: reference values and reference equations for use in clinical practice.

    Science.gov (United States)

    Tveter, Anne Therese; Dagfinrud, Hanne; Moseng, Tuva; Holm, Inger

    2014-07-01

    To provide reference values and reference equations for frequently used clinical field tests of health-related physical fitness for use in clinical practice. Cross-sectional design. General community. Convenience sample of volunteers (N=370) between 18 and 90 years of age were recruited from a wide range of settings (ie, work sites, schools, community centers for older adults) and different geographic locations (ie, urban, suburban, rural) in southeastern Norway. Not applicable. The participants conducted 5 clinical field tests (6-minute walk test, stair test, 30-second sit-to-stand test, handgrip test, fingertip-to-floor test). The results of the field tests showed that performance remained unchanged until approximately 50 years of age; after that, performance deteriorated with increasing age. Grip strength (79%), meters walked in 6 minutes (60%), and seconds used on the stair test (59%) could be well predicted by age, sex, height, and weight in participants ≥50 years of age, whereas the performance on all tests was less well predicted in participants clinical practice. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  13. Mean-field theory and self-consistent dynamo modeling

    International Nuclear Information System (INIS)

    Yoshizawa, Akira; Yokoi, Nobumitsu

    2001-12-01

    Mean-field theory of dynamo is discussed with emphasis on the statistical formulation of turbulence effects on the magnetohydrodynamic equations and the construction of a self-consistent dynamo model. The dynamo mechanism is sought in the combination of the turbulent residual-helicity and cross-helicity effects. On the basis of this mechanism, discussions are made on the generation of planetary magnetic fields such as geomagnetic field and sunspots and on the occurrence of flow by magnetic fields in planetary and fusion phenomena. (author)

  14. In-Situ Systematic Error Correction for Digital Volume Correlation Using a Reference Sample

    KAUST Repository

    Wang, B.

    2017-11-27

    The self-heating effect of a laboratory X-ray computed tomography (CT) scanner causes slight change in its imaging geometry, which induces translation and dilatation (i.e., artificial displacement and strain) in reconstructed volume images recorded at different times. To realize high-accuracy internal full-field deformation measurements using digital volume correlation (DVC), these artificial displacements and strains associated with unstable CT imaging must be eliminated. In this work, an effective and easily implemented reference sample compensation (RSC) method is proposed for in-situ systematic error correction in DVC. The proposed method utilizes a stationary reference sample, which is placed beside the test sample to record the artificial displacement fields caused by the self-heating effect of CT scanners. The detected displacement fields are then fitted by a parametric polynomial model, which is used to remove the unwanted artificial deformations in the test sample. Rescan tests of a stationary sample and real uniaxial compression tests performed on copper foam specimens demonstrate the accuracy, efficacy, and practicality of the presented RSC method.

  15. In-Situ Systematic Error Correction for Digital Volume Correlation Using a Reference Sample

    KAUST Repository

    Wang, B.; Pan, B.; Lubineau, Gilles

    2017-01-01

    The self-heating effect of a laboratory X-ray computed tomography (CT) scanner causes slight change in its imaging geometry, which induces translation and dilatation (i.e., artificial displacement and strain) in reconstructed volume images recorded at different times. To realize high-accuracy internal full-field deformation measurements using digital volume correlation (DVC), these artificial displacements and strains associated with unstable CT imaging must be eliminated. In this work, an effective and easily implemented reference sample compensation (RSC) method is proposed for in-situ systematic error correction in DVC. The proposed method utilizes a stationary reference sample, which is placed beside the test sample to record the artificial displacement fields caused by the self-heating effect of CT scanners. The detected displacement fields are then fitted by a parametric polynomial model, which is used to remove the unwanted artificial deformations in the test sample. Rescan tests of a stationary sample and real uniaxial compression tests performed on copper foam specimens demonstrate the accuracy, efficacy, and practicality of the presented RSC method.

  16. Reference respiratory waveforms by minimum jerk model analysis

    Energy Technology Data Exchange (ETDEWEB)

    Anetai, Yusuke, E-mail: anetai@radonc.med.osaka-u.ac.jp; Sumida, Iori; Takahashi, Yutaka; Yagi, Masashi; Mizuno, Hirokazu; Ogawa, Kazuhiko [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Yamadaoka 2-2, Suita-shi, Osaka 565-0871 (Japan); Ota, Seiichi [Department of Medical Technology, Osaka University Hospital, Yamadaoka 2-15, Suita-shi, Osaka 565-0871 (Japan)

    2015-09-15

    Purpose: CyberKnife{sup ®} robotic surgery system has the ability to deliver radiation to a tumor subject to respiratory movements using Synchrony{sup ®} mode with less than 2 mm tracking accuracy. However, rapid and rough motion tracking causes mechanical tracking errors and puts mechanical stress on the robotic joint, leading to unexpected radiation delivery errors. During clinical treatment, patient respiratory motions are much more complicated, suggesting the need for patient-specific modeling of respiratory motion. The purpose of this study was to propose a novel method that provides a reference respiratory wave to enable smooth tracking for each patient. Methods: The minimum jerk model, which mathematically derives smoothness by means of jerk, or the third derivative of position and the derivative of acceleration with respect to time that is proportional to the time rate of force changed was introduced to model a patient-specific respiratory motion wave to provide smooth motion tracking using CyberKnife{sup ®}. To verify that patient-specific minimum jerk respiratory waves were being tracked smoothly by Synchrony{sup ®} mode, a tracking laser projection from CyberKnife{sup ®} was optically analyzed every 0.1 s using a webcam and a calibrated grid on a motion phantom whose motion was in accordance with three pattern waves (cosine, typical free-breathing, and minimum jerk theoretical wave models) for the clinically relevant superior–inferior directions from six volunteers assessed on the same node of the same isocentric plan. Results: Tracking discrepancy from the center of the grid to the beam projection was evaluated. The minimum jerk theoretical wave reduced the maximum-peak amplitude of radial tracking discrepancy compared with that of the waveforms modeled by cosine and typical free-breathing model by 22% and 35%, respectively, and provided smooth tracking for radial direction. Motion tracking constancy as indicated by radial tracking discrepancy

  17. Reference respiratory waveforms by minimum jerk model analysis

    International Nuclear Information System (INIS)

    Anetai, Yusuke; Sumida, Iori; Takahashi, Yutaka; Yagi, Masashi; Mizuno, Hirokazu; Ogawa, Kazuhiko; Ota, Seiichi

    2015-01-01

    Purpose: CyberKnife"® robotic surgery system has the ability to deliver radiation to a tumor subject to respiratory movements using Synchrony"® mode with less than 2 mm tracking accuracy. However, rapid and rough motion tracking causes mechanical tracking errors and puts mechanical stress on the robotic joint, leading to unexpected radiation delivery errors. During clinical treatment, patient respiratory motions are much more complicated, suggesting the need for patient-specific modeling of respiratory motion. The purpose of this study was to propose a novel method that provides a reference respiratory wave to enable smooth tracking for each patient. Methods: The minimum jerk model, which mathematically derives smoothness by means of jerk, or the third derivative of position and the derivative of acceleration with respect to time that is proportional to the time rate of force changed was introduced to model a patient-specific respiratory motion wave to provide smooth motion tracking using CyberKnife"®. To verify that patient-specific minimum jerk respiratory waves were being tracked smoothly by Synchrony"® mode, a tracking laser projection from CyberKnife"® was optically analyzed every 0.1 s using a webcam and a calibrated grid on a motion phantom whose motion was in accordance with three pattern waves (cosine, typical free-breathing, and minimum jerk theoretical wave models) for the clinically relevant superior–inferior directions from six volunteers assessed on the same node of the same isocentric plan. Results: Tracking discrepancy from the center of the grid to the beam projection was evaluated. The minimum jerk theoretical wave reduced the maximum-peak amplitude of radial tracking discrepancy compared with that of the waveforms modeled by cosine and typical free-breathing model by 22% and 35%, respectively, and provided smooth tracking for radial direction. Motion tracking constancy as indicated by radial tracking discrepancy affected by respiratory

  18. Benchmark problems for numerical implementations of phase field models

    International Nuclear Information System (INIS)

    Jokisaari, A. M.; Voorhees, P. W.; Guyer, J. E.; Warren, J.; Heinonen, O. G.

    2016-01-01

    Here, we present the first set of benchmark problems for phase field models that are being developed by the Center for Hierarchical Materials Design (CHiMaD) and the National Institute of Standards and Technology (NIST). While many scientific research areas use a limited set of well-established software, the growing phase field community continues to develop a wide variety of codes and lacks benchmark problems to consistently evaluate the numerical performance of new implementations. Phase field modeling has become significantly more popular as computational power has increased and is now becoming mainstream, driving the need for benchmark problems to validate and verify new implementations. We follow the example set by the micromagnetics community to develop an evolving set of benchmark problems that test the usability, computational resources, numerical capabilities and physical scope of phase field simulation codes. In this paper, we propose two benchmark problems that cover the physics of solute diffusion and growth and coarsening of a second phase via a simple spinodal decomposition model and a more complex Ostwald ripening model. We demonstrate the utility of benchmark problems by comparing the results of simulations performed with two different adaptive time stepping techniques, and we discuss the needs of future benchmark problems. The development of benchmark problems will enable the results of quantitative phase field models to be confidently incorporated into integrated computational materials science and engineering (ICME), an important goal of the Materials Genome Initiative.

  19. Thermodynamically Consistent Algorithms for the Solution of Phase-Field Models

    KAUST Repository

    Vignal, Philippe

    2016-02-11

    Phase-field models are emerging as a promising strategy to simulate interfacial phenomena. Rather than tracking interfaces explicitly as done in sharp interface descriptions, these models use a diffuse order parameter to monitor interfaces implicitly. This implicit description, as well as solid physical and mathematical footings, allow phase-field models to overcome problems found by predecessors. Nonetheless, the method has significant drawbacks. The phase-field framework relies on the solution of high-order, nonlinear partial differential equations. Solving these equations entails a considerable computational cost, so finding efficient strategies to handle them is important. Also, standard discretization strategies can many times lead to incorrect solutions. This happens because, for numerical solutions to phase-field equations to be valid, physical conditions such as mass conservation and free energy monotonicity need to be guaranteed. In this work, we focus on the development of thermodynamically consistent algorithms for time integration of phase-field models. The first part of this thesis focuses on an energy-stable numerical strategy developed for the phase-field crystal equation. This model was put forward to model microstructure evolution. The algorithm developed conserves, guarantees energy stability and is second order accurate in time. The second part of the thesis presents two numerical schemes that generalize literature regarding energy-stable methods for conserved and non-conserved phase-field models. The time discretization strategies can conserve mass if needed, are energy-stable, and second order accurate in time. We also develop an adaptive time-stepping strategy, which can be applied to any second-order accurate scheme. This time-adaptive strategy relies on a backward approximation to give an accurate error estimator. The spatial discretization, in both parts, relies on a mixed finite element formulation and isogeometric analysis. The codes are

  20. Unsteady wall pressure field of a model A-pillar conical vortex

    International Nuclear Information System (INIS)

    Hoarau, C.; Boree, J.; Laumonier, J.; Gervais, Y.

    2008-01-01

    The spatio-temporal properties of the unsteady wall pressure field of a model A-pillar conical vortex are studied in this paper by combining 2 component LDV measurements and multi-point pressure measurements using off-set microphones. The model body has sharp edges. Detailed LDV measurements are presented and discussed in the vortex region. The fluctuating velocities are the signature of both an unsteady behaviour of the organised vortical structure interacting with the wall and of finer scale turbulence carried by the unsteady flow. A spectral analysis of the fluctuating pressure under the vortex core is used to analyse the link between the temporal and spatial scales of the unsteady aerodynamics and the wall pressure field. We show that the conical vortex is a guide for the velocity perturbations and that their hydrodynamic pressure footprint is transported at the measured mean axial velocity in a local reference frame aligned with the vortex core. Two distinct peaks of coherence can then be associated with perturbations having (i) a length scale of the order of the full length of the conical structure; (ii) a length scale of the order of the width of the structure. These perturbations may correspond to a global meandering of the structure (low frequency contribution) and to large scale perturbations generated during the rolling-up of the unsteady vortex sheet. Notably, the energy containing higher frequency parts of the PSD are only weakly correlated when distant sensors are considered. The three distinct contributions extracted here have a significant impact as far as Cp' is concerned and should be transmitted in very different ways by the car structure because the frequency and length scale range is very distinct

  1. Reference in human and non-human primate communication: What does it take to refer?

    Science.gov (United States)

    Sievers, Christine; Gruber, Thibaud

    2016-07-01

    The concept of functional reference has been used to isolate potentially referential vocal signals in animal communication. However, its relatedness to the phenomenon of reference in human language has recently been brought into question. While some researchers have suggested abandoning the concept of functional reference altogether, others advocate a revision of its definition to include contextual cues that play a role in signal production and perception. Empirical and theoretical work on functional reference has also put much emphasis on how the receiver understands the referential signal. However, reference, as defined in the linguistic literature, is an action of the producer, and therefore, any definition describing reference in non-human animals must also focus on the producer. To successfully determine whether a signal is used to refer, we suggest an approach from the field of pragmatics, taking a closer look at specific situations of signal production, specifically at the factors that influence the production of a signal by an individual. We define the concept of signaller's reference to identify intentional acts of reference produced by a signaller independently of the communicative modality, and illustrate it with a case study of the hoo vocalizations produced by wild chimpanzees during travel. This novel framework introduces an intentional approach to referentiality. It may therefore permit a closer comparison of human and non-human animal referential behaviour and underlying cognitive processes, allowing us to identify what may have emerged solely in the human lineage.

  2. Temperature-based modeling of reference evapotranspiration using several artificial intelligence models: application of different modeling scenarios

    Science.gov (United States)

    Sanikhani, Hadi; Kisi, Ozgur; Maroufpoor, Eisa; Yaseen, Zaher Mundher

    2018-02-01

    The establishment of an accurate computational model for predicting reference evapotranspiration (ET0) process is highly essential for several agricultural and hydrological applications, especially for the rural water resource systems, water use allocations, utilization and demand assessments, and the management of irrigation systems. In this research, six artificial intelligence (AI) models were investigated for modeling ET0 using a small number of climatic data generated from the minimum and maximum temperatures of the air and extraterrestrial radiation. The investigated models were multilayer perceptron (MLP), generalized regression neural networks (GRNN), radial basis neural networks (RBNN), integrated adaptive neuro-fuzzy inference systems with grid partitioning and subtractive clustering (ANFIS-GP and ANFIS-SC), and gene expression programming (GEP). The implemented monthly time scale data set was collected at the Antalya and Isparta stations which are located in the Mediterranean Region of Turkey. The Hargreaves-Samani (HS) equation and its calibrated version (CHS) were used to perform a verification analysis of the established AI models. The accuracy of validation was focused on multiple quantitative metrics, including root mean squared error (RMSE), mean absolute error (MAE), correlation coefficient (R 2), coefficient of residual mass (CRM), and Nash-Sutcliffe efficiency coefficient (NS). The results of the conducted models were highly practical and reliable for the investigated case studies. At the Antalya station, the performance of the GEP and GRNN models was better than the other investigated models, while the performance of the RBNN and ANFIS-SC models was best compared to the other models at the Isparta station. Except for the MLP model, all the other investigated models presented a better performance accuracy compared to the HS and CHS empirical models when applied in a cross-station scenario. A cross-station scenario examination implies the

  3. Physical Limitations of Empirical Field Models: Force Balance and Plasma Pressure

    International Nuclear Information System (INIS)

    Sorin Zaharia; Cheng, C.Z.

    2002-01-01

    In this paper, we study whether the magnetic field of the T96 empirical model can be in force balance with an isotropic plasma pressure distribution. Using the field of T96, we obtain values for the pressure P by solving a Poisson-type equation (gradient) 2 P = (gradient) · (J x B) in the equatorial plane, and 1-D profiles on the Sun-Earth axis by integrating (gradient)P = J x B. We work in a flux coordinate system in which the magnetic field is expressed in terms of Euler potentials. Our results lead to the conclusion that the T96 model field cannot be in equilibrium with an isotropic pressure. We also analyze in detail the computation of Birkeland currents using the Vasyliunas relation and the T96 field, which yields unphysical results, again indicating the lack of force balance in the empirical model. The underlying reason for the force imbalance is likely the fact that the derivatives of the least-square fitted model B are not accurate predictions of the actual magnetospheric field derivatives. Finally, we discuss a possible solution to the problem of lack of force balance in empirical field models

  4. Field theoretic extensions of TDHF techniques

    International Nuclear Information System (INIS)

    Campbell, D.K.

    1979-01-01

    A possible extension of time-dependent Hartree-Fock (TDHF) techniques to relativistic quantum field theories is discussed. A set of extended TDHF equations which incorporates naturally relativistic kinematics and treats the mesons, the effects of which are in ordinary TDHF represented by a nonindependent mean field, as independent dynamical degrees of freedom. In a simple model field theory in one space and one time dimension the extended TDHF equations are solved analytically for certain static field configurations and numerically for the time-dependent scattering configuration. Qualitative features of the scattering solutions as observed in preliminary numerical studies are discussed, and the conclusion is reached by mentioning a number of problems for further research. 22 references

  5. Crisis management: an extended reference framework for decision makers.

    Science.gov (United States)

    Carone, Alessandro; Iorio, Luigi Di

    2013-01-01

    The paper discusses a reference framework for capabilities supporting effective crisis management. This framework has been developed by joining experiences in the field and knowledge of organisational models for crisis management, and executives' empowerment, coaching and behavioural analysis. The paper is aimed at offering further insight to executives on critical success factors and means for managing crisis situations by extending the scope of analysis to human behaviour, to emotions and fears and their correlation with decision making. It is further intended to help familiarise them and to facilitate approaching a path towards emotional awareness.

  6. The state equation of Yang-Mills field dark energy models

    International Nuclear Information System (INIS)

    Zhao Wen; Zhang Yang

    2006-01-01

    In this paper, we study the possibility of building Yang-Mills (YM) field dark energy models with equation of state (EoS) crossing -1, and find that it cannot be realized by the single YM field models, no matter what kind of Lagrangian or initial condition. But the states of -1 -1 to <-1, and it will go to the critical state of ω = -1 with the expansion of the universe, which character is the same as the single YM field models, and the big rip is naturally avoided

  7. Feynman rules for the Standard Model Effective Field Theory in R ξ -gauges

    Science.gov (United States)

    Dedes, A.; Materkowska, W.; Paraskevas, M.; Rosiek, J.; Suxho, K.

    2017-06-01

    We assume that New Physics effects are parametrized within the Standard Model Effective Field Theory (SMEFT) written in a complete basis of gauge invariant operators up to dimension 6, commonly referred to as "Warsaw basis". We discuss all steps necessary to obtain a consistent transition to the spontaneously broken theory and several other important aspects, including the BRST-invariance of the SMEFT action for linear R ξ -gauges. The final theory is expressed in a basis characterized by SM-like propagators for all physical and unphysical fields. The effect of the non-renormalizable operators appears explicitly in triple or higher multiplicity vertices. In this mass basis we derive the complete set of Feynman rules, without resorting to any simplifying assumptions such as baryon-, lepton-number or CP conservation. As it turns out, for most SMEFT vertices the expressions are reasonably short, with a noticeable exception of those involving 4, 5 and 6 gluons. We have also supplemented our set of Feynman rules, given in an appendix here, with a publicly available Mathematica code working with the FeynRules package and producing output which can be integrated with other symbolic algebra or numerical codes for automatic SMEFT amplitude calculations.

  8. Vehicle Reference Generator for Collision-Free Trajectories in Hazardous Maneuvers

    Directory of Open Access Journals (Sweden)

    Cuauhtémoc Acosta Lúa

    2018-01-01

    Full Text Available This paper presents a reference generator for ground vehicles, based on potential fields adapted to the case of vehicular dynamics. The reference generator generates signals to be tracked by the vehicle, corresponding to a trajectory avoiding collisions with obstacles. This generator integrates artificial forces of potential fields of the object surrounding the vehicle. The reference generator is used with a controller to ensure the tracking of the accident-free reference. This approach can be used for vehicle autonomous driving or for active control of manned vehicles. Simulation results, presented for the autonomous driving, consider a scenario inspired by the so-called moose (or elk test, with the presence of other collaborative vehicles.

  9. A thermomechanical far-field model of Yucca Mountain

    International Nuclear Information System (INIS)

    Brandshaug, T.

    1991-04-01

    Thermal and mechanical finite element far-field models have been constructed for a potential repository site in the Topopah Spring Thermal/mechanical Unit at Yucca Mountain on the Nevada Test Site. The models reflect site-specific information that was available at the time of the study on the material properties and structural character of Yucca Mountain. The thermal model simulates transient heat transfer resulting from the emplacement of heat-generating nuclear waste in the repository. Simulation of boiling of the pore water is included in the model. The mechanical model simulates the tuff at Yucca Mountain as being an elastic/plastic, isotropic, heterogeneous continuum with one ubiquitous vertical joint set. The initial conditions of the mechanical model are based on a gravitational stress field. The model uses the temperatures predicted by the thermal finite element model as input to predict thermal stresses and displacements induced by the presence of the repository. Plasticity is incorporated in shear (fracture slip) and tension (fracture opening) by using a Mohr-Coulomb failure criterion. 6 refs., 15 figs., 2 tabs

  10. Geomagnetic core field models in the satellite era

    DEFF Research Database (Denmark)

    Lesur, Vincent; Olsen, Nils; Thomson, Alan W. P.

    2011-01-01

    After a brief review of the theoretical basis and difficulties that modelers are facing, we present three recent models of the geomagnetic field originating in the Earth’s core. All three modeling approaches are using recent observatory and near-Earth orbiting survey satellite data. In each case...

  11. Comparison between two scalar field models using rotation curves of spiral galaxies

    Science.gov (United States)

    Fernández-Hernández, Lizbeth M.; Rodríguez-Meza, Mario A.; Matos, Tonatiuh

    2018-04-01

    Scalar fields have been used as candidates for dark matter in the universe, from axions with masses ∼ 10-5eV until ultra-light scalar fields with masses ∼ Axions behave as cold dark matter while the ultra-light scalar fields galaxies are Bose-Einstein condensate drops. The ultra-light scalar fields are also called scalar field dark matter model. In this work we study rotation curves for low surface brightness spiral galaxies using two scalar field models: the Gross-Pitaevskii Bose-Einstein condensate in the Thomas-Fermi approximation and a scalar field solution of the Klein-Gordon equation. We also used the zero disk approximation galaxy model where photometric data is not considered, only the scalar field dark matter model contribution to rotation curve is taken into account. From the best-fitting analysis of the galaxy catalog we use, we found the range of values of the fitting parameters: the length scale and the central density. The worst fitting results (values of χ red2 much greater than 1, on the average) were for the Thomas-Fermi models, i.e., the scalar field dark matter is better than the Thomas- Fermi approximation model to fit the rotation curves of the analysed galaxies. To complete our analysis we compute from the fitting parameters the mass of the scalar field models and two astrophysical quantities of interest, the dynamical dark matter mass within 300 pc and the characteristic central surface density of the dark matter models. We found that the value of the central mass within 300 pc is in agreement with previous reported results, that this mass is ≈ 107 M ⊙/pc2, independent of the dark matter model. And, on the contrary, the value of the characteristic central surface density do depend on the dark matter model.

  12. Biological and environmental reference materials in CENAM.

    Science.gov (United States)

    Arvizu-Torres, R; Perez-Castorena, A; Salas-Tellez, J A; Mitani-Nakanishi, Y

    2001-06-01

    Since 1994, when the NIST/NOAA Quality Assurance Program in Chemical Measurements was discussed in Queretaro, CENAM, the National Measurement Institute (NMI) of Mexico, has become involved in the development of reference materials. In the field of biological and environmental reference materials, in particular, the NORAMET collaboration program with NIST and NRC, and the North-American Environmental Cooperation signed among three free-trade treaty organizations, have greatly helped the development of the materials metrology program in the newly established CENAM. This paper describes some particularly significant efforts of CENAM in the development of biological and environmental reference materials, on the basis of inter-comparison studies organized with local and governmental environmental agencies of Mexico. In the field of water pollution CENAM has developed a practical proficiency testing (PT) scheme for field laboratories, as a part of registration by local government in the metropolitan area, according to the Mexican Ecological Regulation. The results from these eight PTs in the last 5 years have demonstrated that this scheme has helped ensure the reliability of analytical capability of more than 50 field laboratories in three states, Mexico, D.F., and the States of Mexico and Queretaro. Similar experience has been obtained for more than 70 service units of stack emission measurements in the three states in 1998 and 1999, as a result of the design of a PT scheme for reference gas mixtures. This PT scheme has been accomplished successfully by 30 analytical laboratories who provide monitoring services and perform research on toxic substances (Hg, methylmercury, PCB, etc.) in Mexico. To support these activities, reference samples have been produced through the NIST SRMs, and efforts have been made to increase CENAM's capability in the preparation of primary reference materials in spectrometric solutions and gas mixtures. Collaboration among NMIs has also

  13. Stage line diagram: an age-conditional reference diagram for tracking development.

    Science.gov (United States)

    van Buuren, Stef; Ooms, Jeroen C L

    2009-05-15

    This paper presents a method for calculating stage line diagrams, a novel type of reference diagram useful for tracking developmental processes over time. Potential fields of applications include: dentistry (tooth eruption), oncology (tumor grading, cancer staging), virology (HIV infection and disease staging), psychology (stages of cognitive development), human development (pubertal stages) and chronic diseases (stages of dementia). Transition probabilities between successive stages are modeled as smoothly varying functions of age. Age-conditional references are calculated from the modeled probabilities by the mid-P value. It is possible to eliminate the influence of age by calculating standard deviation scores (SDS). The method is applied to the empirical data to produce reference charts on secondary sexual maturation. The mean of the empirical SDS in the reference population is close to zero, whereas the variance depends on age. The stage line diagram provides quick insight into both status (in SDS) and tempo (in SDS/year) of development of an individual child. Other measures (e.g. height SDS, body mass index SDS) from the same child can be added to the chart. Diagrams for sexual maturation are available as a web application at http://vps.stefvanbuuren.nl/puberty. The stage line diagram expresses status and tempo of discrete changes on a continuous scale. Wider application of these measures scores opens up new analytic possibilities. (c) 2009 John Wiley & Sons, Ltd.

  14. Review of international near-field modeling for high-level waste disposal

    International Nuclear Information System (INIS)

    Apted, M.J.; Andersson, K.; Pescatore, C.

    1993-01-01

    The primary components of nuclear waste repositories that mitigate radionuclide release are the near-field and the far-field subsystems. The near-field encompasses the waste package, which is composed of engineered barriers; the far-field includes the natural barriers. An international survey and review is being conducted on the latest developments in modeling of near-field performance, with particular emphasis on the conceptual and mathematical models for source-term calculations. The objectives of this review will be to establish the status and commonality among models and methods for assessing near-field performance, as well as to identify possible future needs for continued comparison and collaboration. In parallel with the technical evaluation, an international technical Workshop on near-field performance assessment will be held, in association with the Nuclear Energy Agency, on May 11-13, 1993 in Cadarache, France

  15. Modelling the core magnetic field of the earth

    Science.gov (United States)

    Harrison, C. G. A.; Carle, H. M.

    1982-01-01

    It is suggested that radial off-center dipoles located within the core of the earth be used instead of spherical harmonics of the magnetic potential in modeling the core magnetic field. The off-center dipoles, in addition to more realistically modeling the physical current systems within the core, are if located deep within the core more effective at removing long wavelength signals of either potential or field. Their disadvantage is that their positions and strengths are more difficult to compute, and such effects as upward and downward continuation are more difficult to manipulate. It is nevertheless agreed with Cox (1975) and Alldredge and Hurwitz (1964) that physical realism in models is more important than mathematical convenience. A radial dipole model is presented which agrees with observations of secular variation and excursions.

  16. Magnetic field measurements of JT-60SA CS model coil

    Energy Technology Data Exchange (ETDEWEB)

    Obana, Tetsuhiro, E-mail: obana.tetsuhiro@LHD.nifs.ac.jp [National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); Takahata, Kazuya; Hamaguchi, Shinji; Chikaraishi, Hirotaka; Mito, Toshiyuki; Imagawa, Shinsaku [National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); Kizu, Kaname; Murakami, Haruyuki; Natsume, Kyohei; Yoshida, Kiyoshi [Japan Atomic Energy Agency, 801-1 Mukoyama, Naka, Ibaraki 311-0193 (Japan)

    2015-01-15

    Highlights: • Magnetic fields of the JT-60SA CS model coil were measured. • While the coil current was held constant at 20 kA, magnetic fields varied slightly with several different long time constants. • We investigated coils consisting of CIC conductors and having long time constants. - Abstract: In a cold test of the JT-60SA CS model coil, which has a quad-pancake configuration consisting of a Nb{sub 3}Sn cable-in-conduit (CIC) conductor, magnetic fields were measured using Hall sensors. For a holding coil current of 20 kA, measured magnetic fields varied slightly with long time constants in the range 17–571 s, which was much longer than the time constant derived from a measurement using a short straight sample. To validate the measurements, the magnetic fields of the model coil were calculated using a computational model representing the positions of Nb{sub 3}Sn strands inside the CIC conductor. The calculated results were in good agreement with the measurements. Consequently, the validity of the magnetic field measurements was confirmed. Next, we investigated other coils consisting of CIC conductors and having long time constants. The only commonality among the coils was the use of CIC conductors. At present, there is no obvious way to prevent generation of such magnetic-field variations with long time constants.

  17. Cosmological models in globally geodesic coordinates. II. Near-field approximation

    International Nuclear Information System (INIS)

    Liu Hongya

    1987-01-01

    A near-field approximation dealing with the cosmological field near a typical freely falling observer is developed within the framework established in the preceding paper [J. Math. Phys. 28, xxxx(1987)]. It is found that for the matter-dominated era the standard cosmological model of general relativity contains the Newtonian cosmological model, proposed by Zel'dovich, as its near-field approximation in the observer's globally geodesic coordinate system

  18. Multipass Steering: A Reference Implementation

    Science.gov (United States)

    Hennessey, Michael; Tiefenback, Michael

    2015-10-01

    We introduce a reference implementation of a protocol to compute corrections that bring all beams in one of the CEBAF linear accelerators (linac) to axis, including, with a larger tolerance, the lowest energy pass using measured beam trajectory data. This method relies on linear optics as representation of the system; we treat beamline perturbations as magnetic field errors localized to regions between cryomodules, providing the same transverse momentum kick to each beam. We produce a vector of measured beam position data with which we left-multiply the pseudo-inverse of a coefficient array, A, that describes the transport of the beam through the linac using parameters that include the magnetic offsets of the quadrupole magnets, the instrumental offsets of the BPMs, and the beam initial conditions. This process is repeated using a reduced array to produce values that can be applied to the available correcting magnets and beam initial conditions. We show that this method is effective in steering the beam to a straight axis along the linac by using our values in elegant, the accelerator simulation program, on a model of the linac in question. The algorithms in this reference implementation provide a tool for systematic diagnosis and cataloging of perturbations in the beam line. Supported by Jefferson Lab, Old Dominion University, NSF, DOE.

  19. Modelling electricity forward markets by ambit fields

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole; Fred Espen Benth, Fred Espen; Veraart, Almut

    This paper proposes a new modelling framework for electricity forward markets, which is based on ambit fields. The new model can capture many of the stylised facts observed in energy markets. One of the main differences to the traditional models lies in the fact that we do not model the dynamics......, but the forward price directly, where we focus on models which are stationary in time. We give a detailed account on the probabilistic properties of the new model and we discuss martingale conditions and change of measure within the new model class. Also, we derive a model for the spot price which is obtained...

  20. Comparison of plasma input and reference tissue models for analysing [(11)C]flumazenil studies

    NARCIS (Netherlands)

    Klumpers, Ursula M. H.; Veltman, Dick J.; Boellaard, Ronald; Comans, Emile F.; Zuketto, Cassandra; Yaqub, Maqsood; Mourik, Jurgen E. M.; Lubberink, Mark; Hoogendijk, Witte J. G.; Lammertsma, Adriaan A.

    2008-01-01

    A single-tissue compartment model with plasma input is the established method for analysing [(11)C]flumazenil ([(11)C]FMZ) studies. However, arterial cannulation and measurement of metabolites are time-consuming. Therefore, a reference tissue approach is appealing, but this approach has not been

  1. Gravity field modeling at the sea areas using satellite altimetry observations Case study: Gravity field modeling at the Coastal Fars

    International Nuclear Information System (INIS)

    Jomegi, A.

    2007-01-01

    Nowadays, satellite altimetry observations had made it possible to determine sea surface variations, in the global scale, to high degree of precision. Using satellite altimetry observations, Mean Sea Level (MSL) can be determined, which by Kowing Sea Surface Topography (SST), can be converted into high-resolution marine geoid. In this paper we are proposing a method for computation of the Earth's gravity field at the sea areas, which is different from usual methods. Indeed, our method is based on conversion of geoidal heights into gravity potential values at the reference ellipsoid 2 Ea,b , by using ellipsoidal Brun's formula, and forward application of solution of Fixed-Free Two Boundary Value Problem (FFTBVP), previously proposed by the authors for the geoid computations without application of Stokes formula. Numerical results of application of the proposed method at the test area of CoastalFars (at southern part of Iran) show the success of the method. Considering the low cost and high precision of satellite altimetry observations, the proposed method suggests an efficient substitution to shipborne gravity observations for gravity field molding at the sea areas

  2. Neural network-based model reference adaptive control system.

    Science.gov (United States)

    Patino, H D; Liu, D

    2000-01-01

    In this paper, an approach to model reference adaptive control based on neural networks is proposed and analyzed for a class of first-order continuous-time nonlinear dynamical systems. The controller structure can employ either a radial basis function network or a feedforward neural network to compensate adaptively the nonlinearities in the plant. A stable controller-parameter adjustment mechanism, which is determined using the Lyapunov theory, is constructed using a sigma-modification-type updating law. The evaluation of control error in terms of the neural network learning error is performed. That is, the control error converges asymptotically to a neighborhood of zero, whose size is evaluated and depends on the approximation error of the neural network. In the design and analysis of neural network-based control systems, it is important to take into account the neural network learning error and its influence on the control error of the plant. Simulation results showing the feasibility and performance of the proposed approach are given.

  3. 3D modeling of electric fields in the LUX detector

    Science.gov (United States)

    Akerib, D. S.; Alsum, S.; Araújo, H. M.; Bai, X.; Bailey, A. J.; Balajthy, J.; Beltrame, P.; Bernard, E. P.; Bernstein, A.; Biesiadzinski, T. P.; Boulton, E. M.; Brás, P.; Byram, D.; Cahn, S. B.; Carmona-Benitez, M. C.; Chan, C.; Currie, A.; Cutter, J. E.; Davison, T. J. R.; Dobi, A.; Druszkiewicz, E.; Edwards, B. N.; Fallon, S. R.; Fan, A.; Fiorucci, S.; Gaitskell, R. J.; Genovesi, J.; Ghag, C.; Gilchriese, M. G. D.; Hall, C. R.; Hanhardt, M.; Haselschwardt, S. J.; Hertel, S. A.; Hogan, D. P.; Horn, M.; Huang, D. Q.; Ignarra, C. M.; Jacobsen, R. G.; Ji, W.; Kamdin, K.; Kazkaz, K.; Khaitan, D.; Knoche, R.; Larsen, N. A.; Lenardo, B. G.; Lesko, K. T.; Lindote, A.; Lopes, M. I.; Manalaysay, A.; Mannino, R. L.; Marzioni, M. F.; McKinsey, D. N.; Mei, D.-M.; Mock, J.; Moongweluwan, M.; Morad, J. A.; Murphy, A. St. J.; Nehrkorn, C.; Nelson, H. N.; Neves, F.; O'Sullivan, K.; Oliver-Mallory, K. C.; Palladino, K. J.; Pease, E. K.; Rhyne, C.; Shaw, S.; Shutt, T. A.; Silva, C.; Solmaz, M.; Solovov, V. N.; Sorensen, P.; Sumner, T. J.; Szydagis, M.; Taylor, D. J.; Taylor, W. C.; Tennyson, B. P.; Terman, P. A.; Tiedt, D. R.; To, W. H.; Tripathi, M.; Tvrznikova, L.; Uvarov, S.; Velan, V.; Verbus, J. R.; Webb, R. C.; White, J. T.; Whitis, T. J.; Witherell, M. S.; Wolfs, F. L. H.; Xu, J.; Yazdani, K.; Young, S. K.; Zhang, C.

    2017-11-01

    This work details the development of a three-dimensional (3D) electric field model for the LUX detector. The detector took data to search for weakly interacting massive particles (WIMPs) during two periods. After the first period completed, a time-varying non-uniform negative charge developed in the polytetrafluoroethylene (PTFE) panels that define the radial boundary of the detector's active volume. This caused electric field variations in the detector in time, depth and azimuth, generating an electrostatic radially-inward force on electrons on their way upward to the liquid surface. To map this behavior, 3D electric field maps of the detector's active volume were generated on a monthly basis. This was done by fitting a model built in COMSOL Multiphysics to the uniformly distributed calibration data that were collected on a regular basis. The modeled average PTFE charge density increased over the course of the exposure from -3.6 to -5.5 μC/m2. From our studies, we deduce that the electric field magnitude varied locally while the mean value of the field of ~200 V/cm remained constant throughout the exposure. As a result of this work the varying electric fields and their impact on event reconstruction and discrimination were successfully modeled.

  4. Integrable models in 1+1 dimensional quantum field theory

    International Nuclear Information System (INIS)

    Faddeev, Ludvig.

    1982-09-01

    The goal of this lecture is to present a unifying view on the exactly soluble models. There exist several reasons arguing in favor of the 1+1 dimensional models: every exact solution of a field-theoretical model can teach about the ability of quantum field theory to describe spectrum and scattering; some 1+1 d models have physical applications in the solid state theory. There are several ways to become acquainted with the methods of exactly soluble models: via classical statistical mechanics, via Bethe Ansatz, via inverse scattering method. Fundamental Poisson bracket relation FPR and/or fundamental commutation relations FCR play fundamental role. General classification of FPR is given with promizing generalizations to FCR

  5. Statistical mechanics of lattice boson field theory

    International Nuclear Information System (INIS)

    Baker, G.A. Jr.

    1977-01-01

    A lattice approximation to Euclidean, boson quantum field theory is expressed in terms of the thermodynamic properties of a classical statistical mechanical system near its critical point in a sufficiently general way to permit the inclusion of an anomalous dimension of the vacuum. Using the thermodynamic properties of the Ising model, one can begin to construct nontrivial (containing scattering) field theories in 2, 3, and 4 dimensions. It is argued that, depending on the choice of the bare coupling constant, there are three types of behavior to be expected: the perturbation theory region, the renormalization group fixed point region, and the Ising model region. 24 references

  6. Electrical engineering a pocket reference

    CERN Document Server

    Schmidt-Walter, Heinz

    2007-01-01

    This essential reference offers you a well-organized resource for accessing the basic electrical engineering knowledge you need for your work. Whether you're an experienced engineer who appreciates an occasional refresher in key areas, or a student preparing to enter the field, Electrical Engineering: A Pocket Reference provides quick and easy access to fundamental principles and their applications. You also find an extensive collection of time-saving equations that help simplify your daily projects.Supported with more than 500 diagrams and figures, 60 tables, and an extensive index, this uniq

  7. Mapping of radio frequency electromagnetic field exposure levels in outdoor environment and comparing with reference levels for general public health.

    Science.gov (United States)

    Cansiz, Mustafa; Abbasov, Teymuraz; Kurt, M Bahattin; Celik, A Recai

    2018-03-01

    In this study, radio frequency electromagnetic field exposure levels were measured on the main streets in the city center of Diyarbakır, Turkey. Measured electric field levels were plotted on satellite imagery of Diyarbakır and were compared with exposure guidelines published by the International Commission on Non-Ionizing Radiation Protection (ICNIRP). Exposure measurements were performed in dense urban, urban and suburban areas each day for 7 consecutive days. The measurement system consisted of high precision and portable spectrum analyzer, three-axis electric field antenna, connection cable and a laptop which was used to record the measurement samples as a data logger. The highest exposure levels were detected for two places, which are called Diclekent and Batıkent. It was observed that the highest instantaneous electric field strength value for Batıkent was 7.18 V/m and for Diclekent was 5.81 V/m. It was statistically determined that the main contributor band to the total exposure levels was Universal Mobile Telecommunications System band. Finally, it was concluded that all measured exposure levels were lower than the reference levels recommended by ICNIRP for general public health.

  8. Soliton excitations in polyacetylene and relativistic field theory models

    International Nuclear Information System (INIS)

    Campbell, D.K.; Bishop, A.R.; Los Alamos Scientific Lab., NM

    1982-01-01

    A continuum model of a Peierls-dimerized chain, as described generally by Brazovskii and discussed for the case of polyacetylene by Takayama, Lin-Liu and Maki (TLM), is considered. The continuum (Bogliubov-de Gennes) equations arising in this model of interacting electrons and phonons are shown to be equivalent to the static, semiclassical equations for a solvable model field theory of self-coupled fermions - the N = 2 Gross-Neveu model. Based on this equivalence we note the existence of soliton defect states in polyacetylene that are additional to, and qualitatively different from, the amplitude kinks commonly discussed. The new solutions do not have the topological stability of kinks but are essentially conventional strong-coupling polarons in the dimerized chain. They carry spin (1/2) and charge (+- e). In addition, we discuss further areas in which known field theory results may apply to a Peierls-dimerized chain, including relations between phenomenological PHI 4 and continuuum electron-phonon models, and the structure of the fully quantum versus mean field theories. (orig.)

  9. Reference model of future ubiquitous convergent network and context-aware telecommunication service platform

    Institute of Scientific and Technical Information of China (English)

    QIAO Xiu-quan; LI Xiao-feng; LIANG Shou-qing

    2006-01-01

    A reference model for future ubiquitous convergent network is analyzed. To provide user-centric, intelligent,personalized service, this article presents a context-aware telecommunication service platform (CaTSP) to adapt to dynamically changing context. This article focuses on the new design method of context-aware telecommunication service platform and its architecture. Through the use of model-driven architecture (MDA) and semantic web technologies, CaTSP can enable context reasoning and service personalization adaption.This article explores a new approach for service intelligence,personalization, and adaptability in the semantic web service computing era.

  10. Atomistic modeling of metal surfaces under electric fields: direct coupling of electric fields to a molecular dynamics algorithm

    CERN Document Server

    Djurabekova, Flyura; Pohjonen, Aarne; Nordlund, Kai

    2011-01-01

    The effect of electric fields on metal surfaces is fairly well studied, resulting in numerous analytical models developed to understand the mechanisms of ionization of surface atoms observed at very high electric fields, as well as the general behavior of a metal surface in this condition. However, the derivation of analytical models does not include explicitly the structural properties of metals, missing the link between the instantaneous effects owing to the applied field and the consequent response observed in the metal surface as a result of an extended application of an electric field. In the present work, we have developed a concurrent electrodynamic–molecular dynamic model for the dynamical simulation of an electric-field effect and subsequent modification of a metal surface in the framework of an atomistic molecular dynamics (MD) approach. The partial charge induced on the surface atoms by the electric field is assessed by applying the classical Gauss law. The electric forces acting on the partially...

  11. Shape Modelling Using Markov Random Field Restoration of Point Correspondences

    DEFF Research Database (Denmark)

    Paulsen, Rasmus Reinhold; Hilger, Klaus Baggesen

    2003-01-01

    A method for building statistical point distribution models is proposed. The novelty in this paper is the adaption of Markov random field regularization of the correspondence field over the set of shapes. The new approach leads to a generative model that produces highly homogeneous polygonized sh...

  12. Isospin-dependent properties of asymmetric nuclear matter in relativistic mean-field models

    OpenAIRE

    Chen, Lie-Wen; Ko, Che Ming; Li, Bao-An

    2007-01-01

    Using various relativistic mean-field models, including the nonlinear ones with meson field self-interactions, those with density-dependent meson-nucleon couplings, and the point-coupling models without meson fields, we have studied the isospin-dependent bulk and single-particle properties of asymmetric nuclear matter. In particular, we have determined the density dependence of nuclear symmetry energy from these different relativistic mean-field models and compare the results with the constra...

  13. Dosimetric verification for radiotherapy quality audit under reference and non-reference conditions in Jiangsu province

    International Nuclear Information System (INIS)

    Wang Jin; Yu Ningle; Yang Chunyong; Du Xiang; Chen Wei; Luo Suming

    2014-01-01

    Objective: To verify the methodology for auditing dosimetric parameters in reference and non-reference conditions with thermoluminescent dosimeters (TLDs). Methods: Under reference and non-reference conditions, the established TLD methods were used to observe the absorbed dose variations with depth, SSD, field size and 45 wedges for 10 photon beams at 5 hospitals. Dosimetric parameters, including doses at D_m_a_x points in axis, on 5 electron beams of 9 MeV were measured. The measurement results were compared between the TLDs and plane parallel ionization chambers. Results: For 6 MV photon beams, the relative deviation of between finger ionization chamber method and TLD chips was in the range of -1.7% to 5.4% under on-axis non-reference conditions, and -6.3% to -0.6% under off-axis non-reference conditions, respectively, all within the range of ≤ ±7% as required by the IAEA. The relative deviation between plane parallel chamber and TLD method was -2.3% to 3.7%, within ±5% as required by the IAEA. Conclusions: It is convenient and feasible to use TLD method for quality audits of dosimetric parameters in radiotherapy. (authors)

  14. A comprehensive model of the quiet-time, near-Earth magnetic field: phase 3

    DEFF Research Database (Denmark)

    Sabaka, T.J.; Olsen, Nils; Langel, R.A.

    2002-01-01

    been modelled simultaneously, with fields from other sources being modelled separately. Such a scheme, however, can introduce spurious features, especially when the spatial and temporal scales of the fields overlap. A new model, designated CM3 (Comprehensive Model: phase 3), is the third in a series...... of efforts to coestimate fields from all of these sources. This model has been derived from quiet-time Magsat and POGO satellite and observatory hourly means measurements for the period 1960-1985. It represents a significant advance in the treatment of the aforementioned field sources over previous attempts...... parametrization and estimation of the lithospheric field. The result is a model that describes well the 591 432 data with 16 594 parameters, implying a data-to-parameter ratio of 36, which is larger than several popular field models....

  15. A new birthweight reference in Guangzhou, southern China, and its comparison with the global reference.

    Science.gov (United States)

    He, Jian-Rong; Xia, Hui-Min; Liu, Yu; Xia, Xiao-Yan; Mo, Wei-Jian; Wang, Ping; Cheng, Kar Keung; Leung, Gabriel M; Feng, Qiong; Schooling, C Mary; Qiu, Xiu

    2014-12-01

    To formulate a new birthweight reference for different gestational ages in Guangzhou, southern China, and compare it with the currently used reference in China and the global reference. All singleton live births of more than 26 weeks' gestational age recorded in the Guangzhou Perinatal Health Care and Delivery Surveillance System for the years 2009, 2010 and 2011 (n=510 837) were retrospectively included in the study. In addition, the study sample was supplemented by all singleton live births (n=3538) at gestational ages 26-33 weeks from 2007 and 2008. We used Gaussian mixture models and robust regression to exclude outliers of birth weight and then applied Generalized Additive Models for Location, Scale, and Shape (GAMLSS) to generate smoothed percentile curves separately for gender and parity. Of infants defined as small for gestational age (SGA) in the new reference, 15.3-47.7% (depending on gestational age) were considered appropriate for gestational age (AGA) by the currently used reference of China. Of the infants defined as SGA by the new reference, 9.2% with gestational ages 34-36 weeks and 14.3% with 37-41 weeks were considered AGA by the global reference. At the 50th centile line, the new reference curve was similar to that of the global reference for gestational ages 26-33 weeks and above the global reference for 34-40 weeks. The new birthweight reference based on birthweight data for neonates in Guangzhou, China, differs from the reference currently used in China and the global reference, and appears to be more relevant to the local population. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  16. Benchmark Modeling of the Near-Field and Far-Field Wave Effects of Wave Energy Arrays

    Energy Technology Data Exchange (ETDEWEB)

    Rhinefrank, Kenneth E; Haller, Merrick C; Ozkan-Haller, H Tuba

    2013-01-26

    This project is an industry-led partnership between Columbia Power Technologies and Oregon State University that will perform benchmark laboratory experiments and numerical modeling of the near-field and far-field impacts of wave scattering from an array of wave energy devices. These benchmark experimental observations will help to fill a gaping hole in our present knowledge of the near-field effects of multiple, floating wave energy converters and are a critical requirement for estimating the potential far-field environmental effects of wave energy arrays. The experiments will be performed at the Hinsdale Wave Research Laboratory (Oregon State University) and will utilize an array of newly developed Buoys' that are realistic, lab-scale floating power converters. The array of Buoys will be subjected to realistic, directional wave forcing (1:33 scale) that will approximate the expected conditions (waves and water depths) to be found off the Central Oregon Coast. Experimental observations will include comprehensive in-situ wave and current measurements as well as a suite of novel optical measurements. These new optical capabilities will include imaging of the 3D wave scattering using a binocular stereo camera system, as well as 3D device motion tracking using a newly acquired LED system. These observing systems will capture the 3D motion history of individual Buoys as well as resolve the 3D scattered wave field; thus resolving the constructive and destructive wave interference patterns produced by the array at high resolution. These data combined with the device motion tracking will provide necessary information for array design in order to balance array performance with the mitigation of far-field impacts. As a benchmark data set, these data will be an important resource for testing of models for wave/buoy interactions, buoy performance, and far-field effects on wave and current patterns due to the presence of arrays. Under the proposed project we will initiate

  17. Temperature Field-Wind Velocity Field Optimum Control of Greenhouse Environment Based on CFD Model

    Directory of Open Access Journals (Sweden)

    Yongbo Li

    2014-01-01

    Full Text Available The computational fluid dynamics technology is applied as the environmental control model, which can include the greenhouse space. Basic environmental factors are set to be the control objects, the field information is achieved via the division of layers by height, and numerical characteristics of each layer are used to describe the field information. Under the natural ventilation condition, real-time requirements, energy consumption, and distribution difference are selected as index functions. The optimization algorithm of adaptive simulated annealing is used to obtain optimal control outputs. A comparison with full-open ventilation shows that the whole index can be reduced at 44.21% and found that a certain mutual exclusiveness exists between the temperature and velocity field in the optimal course. All the results indicate that the application of CFD model has great advantages to improve the control accuracy of greenhouse.

  18. A Modified Model Reference Adaptive Control for a Single Motor of Latch Type Control Element Drive Mechanism

    International Nuclear Information System (INIS)

    Park, Bae Jeong

    2016-01-01

    A modified Model Reference Adaptive Control (MRAC) for a single motor of latch type Control Element Drive Mechanism (CEDM) is described herein. The CEDM has complicated dynamic characteristics including electrical, mechanical, and magnetic effects. The previous control system has utilized a Proportional-Integral (PI) controller, and the control performance is limited according to nonlinear dynamic characteristics and environmental conditions. The modified MRAC using system identification (ID) technique improves the control performance in the operating condition such as model parameter variation and environmental condition change. The modified MRAC using the identified reference model with feed-forward gain and 180Hz noise reduction filter presents better performance under normal and/or abnormal condition. The simplified reference model can make H/W implementation more practical on the viewpoint of less computation and good performance. Actually, the CEDM controller shall be capable of controlling 101 control element assemblies (CEAs) individually in the nuclear power plant. Because the load conditions and the environmental condition around the 101 CEAs are all different minutely, the proposed modified MRAC can be a good practice. The modified MRAC controller will be applied in the real nuclear power plant later and this will overcome some weak point of PI controller

  19. Reference dosimetry for helical tomotherapy: Practical implementation and a multicenter validation

    International Nuclear Information System (INIS)

    De Ost, B.; Schaeken, B.; Vynckier, S.; Sterpin, E.; Van den Weyngaert, D.

    2011-01-01

    Purpose: The aim of this study was to implement a protocol for reference dosimetry in tomotherapy and to validate the beam output measurements with an independent dosimetry system. Methods: Beam output was measured at the reference depth of 10 cm in water for the following three cases: (1) a 5 x 10 cm 2 static machine specific reference field (MSR), (2) a rotational 5 x 10 cm 2 field without modulation and no tabletop in the beam, (3) a plan class specific reference (PCSR) field defined as a rotational homogeneous dose delivery to a cylindrical shaped target volume: plan with modulation and table-top movement. The formalism for reference dosimetry of small and nonstandard fields [Med.Phys.35: 5179-5186, 2008] and QA recommendations [Med.Phys.37: 4817-4853, 2010] were adopted in the dose measurement protocol. All ionization chamber measurements were verified independently using alanine/EPR dosimetry. As a pilot study, the beam output was measured on tomotherapy Hi-art systems at three other centers and directly compared to the centers specifications and to alanine dosimetry. Results: For the four centers, the mean static output at a depth of 10 cm in water and SAD = 85 cm, measured with an A1SL chamber following the TG-148 report was 6.238 Gy/min ± 0.058 (1 SD); the rotational output was 6.255 Gy/min ± 0.069 (1 SD). The dose stated by the center was found in good agreement with the measurements of the visiting team: D center /D visit = 1.000 ± 0.003 (1 SD). The A1SL chamber measurements were all in good agreement with Alanine/EPR dosimetry. Going from the static reference field to the rotational/non modulated field the dose rate remains constant within 0.2% except for one center where a deviation of 1.3% was detected. Conclusions: Following the TG-148 report, beam output measurements in water at the reference depth using a local protocol, as developed at different centers, was verified. The measurements were found in good agreement with alanine/EPR dosimetry. The

  20. A simplified model of polar cap electric fields

    International Nuclear Information System (INIS)

    D'Angelo, N.

    1977-01-01

    A simple-minded 'model' is used in order to visualize the gross features of polar cap electric fields, in particular the 'diode' effect which had emerged already from earlier observations and the asymmetry between the electric fields observed on the dawn and dusk sides of the polar cap, which depends on Bsub(y)