WorldWideScience

Sample records for models involving large

  1. The Undergraduate ALFALFA Team: A Model for Involving Undergraduates in Large Astronomy Collaborations

    Science.gov (United States)

    Craig, David W.; Koopmann, Rebecca A.; Haynes, Martha P.; Undergraduate ALFALFA Team, ALFALFA Team

    2016-01-01

    The NSF-sponsored Undergraduate ALFALFA (Arecibo Legacy Fast ALFA) Team (UAT) has allowed faculty and students from a wide range of public and private colleges and especially those with small astronomy programs to learn how science is accomplished in a large collaboration while contributing to the scientific goals of a legacy radio astronomy survey. This effort has been made possible through the collaboration of the ALFALFA PIs and graduate students, Arecibo Observatory staff, and the faculty at 19 undergraduate-focussed institutions. In this talk, we will discuss how the UAT model works for the ALFALFA project and lessons learned from our efforts over the 8 years of grant funding. We will provide suggestions on how the model could be applied to other legacy projects, particularly in such areas as online collaboration and software usage by undergraduates. This work has been supported by NSF grants AST-0724918/0902211, AST-075267/0903394, AST-0725380, and AST-1211005.

  2. Multiscale method for modeling binding phenomena involving large objects: application to kinesin motor domains motion along microtubules.

    Science.gov (United States)

    Li, Lin; Alper, Joshua; Alexov, Emil

    2016-03-18

    Many biological phenomena involve the binding of proteins to a large object. Because the electrostatic forces that guide binding act over large distances, truncating the size of the system to facilitate computational modeling frequently yields inaccurate results. Our multiscale approach implements a computational focusing method that permits computation of large systems without truncating the electrostatic potential and achieves the high resolution required for modeling macromolecular interactions, all while keeping the computational time reasonable. We tested our approach on the motility of various kinesin motor domains. We found that electrostatics help guide kinesins as they walk: N-kinesins towards the plus-end, and C-kinesins towards the minus-end of microtubules. Our methodology enables computation in similar, large systems including protein binding to DNA, viruses, and membranes.

  3. An MCDA and GIS coupling conceptual model to be used in a circular decision process by stakeholders involved in large wind farm projects

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez, M. [Quebec Univ., Rimouski, PQ (Canada). Laboratoire de Recherche en Energie Eolienne; Quebec Univ., Montreal, PQ (Canada). GEIGER; Waaub, J.P. [Quebec Univ., Montreal, PQ (Canada). GEIGER; Ilinca, A. [Quebec Univ., Rimouski, PQ (Canada). Laboratoire de Recherche en Energie Eolienne

    2010-07-01

    This poster presentation described an MCDA and geographic information system (GIS) coupling conceptual model designed for use in stakeholder decision-making processes for large wind farm projects. The model was comprised of 4 modules and 4 stakeholder categories that considered the environment and communities involved in the project. The integrated modelling approach was designed to ensure a transparent decision-making process. The modules included: (1) an MCDA module, (2) a local expertise and scientific knowledge module, (3) a stakeholder involvement module, and (4) a participatory GIS module. The model can be used to structure issues during consultation procedures, as well as to conduct preference analyses and to identify indicators. Examples of stakeholder weighting were included. tabs., figs.

  4. A novel orally available inhibitor of focal adhesion signaling increases survival in a xenograft model of diffuse large B-cell lymphoma with central nervous system involvement.

    Science.gov (United States)

    Bosch, Rosa; Moreno, María José; Dieguez-Gonzalez, Rebeca; Céspedes, María Virtudes; Gallardo, Alberto; Trias, Manuel; Grañena, Albert; Sierra, Jorge; Casanova, Isolda; Mangues, Ramon

    2013-08-01

    Central nervous system dissemination is a relatively uncommon but almost always fatal complication in diffuse large B-cell lymphoma patients. Optimal therapy for central nervous involvement in this malignancy has not been established. In this paper, we aimed to evaluate the therapeutic effect of E7123, a celecoxib derivative that inhibits focal adhesion signaling, in a novel xenograft model of diffuse large B-cell lymphoma with central nervous system involvement. Cells obtained after disaggregation of HT subcutaneous tumors (HT-SC cells) were intravenously injected in NOD/SCID mice. These mice received oral vehicle or 75 mg/kg of E7123 daily until they were euthanized for weight loss or signs of sickness. The antitumor effect of E7123 was validated in an independent experiment using a bioluminescent mouse model. Intravenously injected HT-SC cells showed higher take rate and higher central nervous system tropism (associated with increased expression of β1-integrin and p130Cas proteins) than HT cells. The oral administration of E7123 significantly increased survival time in 2 independent experiments using mice injected with unmodified or bioluminescent HT-SC cells. We have developed a new xenograft model of diffuse large B-cell lymphoma with central nervous system involvement that can be used in the pre-clinical evaluation of new drugs for this malignancy. E7123 is a new, well-tolerated and orally available therapeutic agent that merits further investigation since it may improve current management of diffuse large B-cell lymphoma patients with central nervous system involvement.

  5. Severities of transportation accidents involving large packages

    Energy Technology Data Exchange (ETDEWEB)

    Dennis, A.W.; Foley, J.T. Jr.; Hartman, W.F.; Larson, D.W.

    1978-05-01

    The study was undertaken to define in a quantitative nonjudgmental technical manner the abnormal environments to which a large package (total weight over 2 tons) would be subjected as the result of a transportation accident. Because of this package weight, air shipment was not considered as a normal transportation mode and was not included in the study. The abnormal transportation environments for shipment by motor carrier and train were determined and quantified. In all cases the package was assumed to be transported on an open flat-bed truck or an open flat-bed railcar. In an earlier study, SLA-74-0001, the small-package environments were investigated. A third transportation study, related to the abnormal environment involving waterways transportation, is now under way at Sandia Laboratories and should complete the description of abnormal transportation environments. Five abnormal environments were defined and investigated, i.e., fire, impact, crush, immersion, and puncture. The primary interest of the study was directed toward the type of large package used to transport radioactive materials; however, the findings are not limited to this type of package but can be applied to a much larger class of material shipping containers.

  6. Modeling interdisciplinary activities involving Mathematics

    DEFF Research Database (Denmark)

    Iversen, Steffen Møllegaard

    2006-01-01

    In this paper a didactical model is presented. The goal of the model is to work as a didactical tool, or conceptual frame, for developing, carrying through and evaluating interdisciplinary activities involving the subject of mathematics and philosophy in the high schools. Through the terms...... domains (Michelsen, 2001, 2005a, 2005b). Furthermore the theoretical description rest on a series of qualitative interviews with teachers from the Danish high school (grades 9-11) conducted recently. The special case of concrete interdisciplinary activities between mathematics and philosophy is also...

  7. Modeling interdisciplinary activities involving Mathematics

    DEFF Research Database (Denmark)

    Iversen, Steffen Møllegaard

    2006-01-01

    In this paper a didactical model is presented. The goal of the model is to work as a didactical tool, or conceptual frame, for developing, carrying through and evaluating interdisciplinary activities involving the subject of mathematics and philosophy in the high schools. Through the terms...... of Horizontal Intertwining, Vertical Structuring and Horizontal Propagation the model consists of three phases, each considering different aspects of the nature of interdisciplinary activities. The theoretical modelling is inspired by work which focuses on the students abilities to concept formation in expanded...... domains (Michelsen, 2001, 2005a, 2005b). Furthermore the theoretical description rest on a series of qualitative interviews with teachers from the Danish high school (grades 9-11) conducted recently. The special case of concrete interdisciplinary activities between mathematics and philosophy is also...

  8. Observations involving broadband impedance modelling

    Energy Technology Data Exchange (ETDEWEB)

    Berg, J.S. [Stanford Linear Accelerator Center, Menlo Park, CA (United States)

    1996-08-01

    Results for single- and multi-bunch instabilities can be significantly affected by the precise model that is used for the broadband impedance. This paper discusses three aspects of broadband impedance modelling. The first is an observation of the effect that a seemingly minor change in an impedance model has on the single-bunch mode coupling threshold. The second is a successful attempt to construct a model for the high-frequency tails of an r.f. cavity. The last is a discussion of requirements for the mathematical form of an impedance which follow from the general properties of impedances. (author)

  9. Observations involving broadband impedance modelling

    Energy Technology Data Exchange (ETDEWEB)

    Berg, J.S.

    1995-08-01

    Results for single- and multi-bunch instabilities can be significantly affected by the precise model that is used for the broadband impendance. This paper discusses three aspects of broadband impendance modeling. The first is an observation of the effect that a seemingly minor change in an impedance model has on the single-bunch mode coupling threshold. The second is a successful attempt to construct a model for the high-frequency tails of an r.f cavity. The last is a discussion of requirements for the mathematical form of an impendance which follow from the general properties of impendances.

  10. Multifocal Extranodal Involvement of Diffuse Large B-Cell Lymphoma

    Directory of Open Access Journals (Sweden)

    Devrim Cabuk

    2013-01-01

    Full Text Available Endobronchial involvement of extrapulmonary malignant tumors is uncommon and mostly associated with breast, kidney, colon, and rectum carcinomas. A 68-year-old male with a prior diagnosis of colon non-Hodgkin lymphoma (NHL was admitted to the hospital with a complaint of cough, sputum, and dyspnea. The chest radiograph showed right hilar enlargement and opacity at the right middle zone suggestive of a mass lesion. Computed tomography of thorax revealed a right-sided mass lesion extending to thoracic wall with the destruction of the third and the fourth ribs and a right hilar mass lesion. Fiberoptic bronchoscopy was performed in order to evaluate endobronchial involvement and showed stenosis with mucosal tumor infiltration in right upper lobe bronchus. The pathological examination of bronchoscopic biopsy specimen reported diffuse large B-cell lymphoma and the patient was accepted as the endobronchial recurrence of sigmoid colon NHL. The patient is still under treatment of R-ICE (rituximab-ifosfamide-carboplatin-etoposide chemotherapy and partial regression of pulmonary lesions was noted after 3 courses of treatment.

  11. Metal-Oxide Film Conversions Involving Large Anions

    Energy Technology Data Exchange (ETDEWEB)

    Pretty, S.; Zhang, X.; Shoesmith, D.W.; Wren, J.C. [The University of Western Ontario, Chemistry Department, 1151 Richmond St., N6A 5B7, London, Ontario (Canada)

    2008-07-01

    The main objective of my research is to establish the mechanism and kinetics of metal-oxide film conversions involving large anions (I{sup -}, Br{sup -}, S{sup 2-}). Within a given group, the anions will provide insight on the effect of anion size on the film conversion, while comparison of Group 6 and Group 7 anions will provide insight on the effect of anion charge. This research has a range of industrial applications, for example, hazardous radioiodine can be immobilized by reaction with Ag to yield AgI. From the perspective of public safety, radioiodine is one of the most important fission products from the uranium fuel because of its large fuel inventory, high volatility, and radiological hazard. Additionally, because of its mobility, the gaseous iodine concentration is a critical parameter for safety assessment and post-accident management. A full kinetic analysis using electrochemical techniques has been performed on the conversion of Ag{sub 2}O to (1) AgI and (2) AgBr. (authors)

  12. Large Unifying Hybrid Supernetwork Model

    Institute of Scientific and Technical Information of China (English)

    LIU; Qiang; FANG; Jin-qing; LI; Yong

    2015-01-01

    For depicting multi-hybrid process,large unifying hybrid network model(so called LUHNM)has two sub-hybrid ratios except dr.They are deterministic hybrid ratio(so called fd)and random hybrid ratio(so called gr),respectively.

  13. Large N Expansion. Vector Models

    CERN Document Server

    Nissimov, E; Nissimov, Emil; Pacheva, Svetlana

    2006-01-01

    Preliminary version of a contribution to the "Quantum Field Theory. Non-Perturbative QFT" topical area of "Modern Encyclopedia of Mathematical Physics" (SELECTA), eds. Aref'eva I, and Sternheimer D, Springer (2007). Consists of two parts - "main article" (Large N Expansion. Vector Models) and a "brief article" (BPHZL Renormalization).

  14. Bullying Prevention and the Parent Involvement Model

    Science.gov (United States)

    Kolbert, Jered B.; Schultz, Danielle; Crothers, Laura M.

    2014-01-01

    A recent meta-analysis of bullying prevention programs provides support for social-ecological theory, in which parent involvement addressing child bullying behaviors is seen as important in preventing school-based bullying. The purpose of this manuscript is to suggest how Epstein and colleagues' parent involvement model can be used as a…

  15. Learning models of activities involving interacting objects

    DEFF Research Database (Denmark)

    Manfredotti, Cristina; Pedersen, Kim Steenstrup; Hamilton, Howard J.;

    2013-01-01

    We propose the LEMAIO multi-layer framework, which makes use of hierarchical abstraction to learn models for activities involving multiple interacting objects from time sequences of data concerning the individual objects. Experiments in the sea navigation domain yielded learned models that were...

  16. Learning models of activities involving interacting objects

    DEFF Research Database (Denmark)

    Manfredotti, Cristina; Pedersen, Kim Steenstrup; Hamilton, Howard J.

    2013-01-01

    We propose the LEMAIO multi-layer framework, which makes use of hierarchical abstraction to learn models for activities involving multiple interacting objects from time sequences of data concerning the individual objects. Experiments in the sea navigation domain yielded learned models that were t...

  17. Models of large scale structure

    Energy Technology Data Exchange (ETDEWEB)

    Frenk, C.S. (Physics Dept., Univ. of Durham (UK))

    1991-01-01

    The ingredients required to construct models of the cosmic large scale structure are discussed. Input from particle physics leads to a considerable simplification by offering concrete proposals for the geometry of the universe, the nature of the dark matter and the primordial fluctuations that seed the growth of structure. The remaining ingredient is the physical interaction that governs dynamical evolution. Empirical evidence provided by an analysis of a redshift survey of IRAS galaxies suggests that gravity is the main agent shaping the large-scale structure. In addition, this survey implies large values of the mean cosmic density, {Omega}> or approx.0.5, and is consistent with a flat geometry if IRAS galaxies are somewhat more clustered than the underlying mass. Together with current limits on the density of baryons from Big Bang nucleosynthesis, this lends support to the idea of a universe dominated by non-baryonic dark matter. Results from cosmological N-body simulations evolved from a variety of initial conditions are reviewed. In particular, neutrino dominated and cold dark matter dominated universes are discussed in detail. Finally, it is shown that apparent periodicities in the redshift distributions in pencil-beam surveys arise frequently from distributions which have no intrinsic periodicity but are clustered on small scales. (orig.).

  18. Learning models of activities involving interacting objects

    DEFF Research Database (Denmark)

    Manfredotti, Cristina; Pedersen, Kim Steenstrup; Hamilton, Howard J.;

    2013-01-01

    We propose the LEMAIO multi-layer framework, which makes use of hierarchical abstraction to learn models for activities involving multiple interacting objects from time sequences of data concerning the individual objects. Experiments in the sea navigation domain yielded learned models that were...... then successfully applied to activity recognition, activity simulation and multi-target tracking. Our method compares favourably with respect to previously reported results using Hidden Markov Models and Relational Particle Filtering....

  19. Spatial occupancy models for large data sets

    Science.gov (United States)

    Johnson, Devin S.; Conn, Paul B.; Hooten, Mevin B.; Ray, Justina C.; Pond, Bruce A.

    2013-01-01

    Since its development, occupancy modeling has become a popular and useful tool for ecologists wishing to learn about the dynamics of species occurrence over time and space. Such models require presence–absence data to be collected at spatially indexed survey units. However, only recently have researchers recognized the need to correct for spatially induced overdisperison by explicitly accounting for spatial autocorrelation in occupancy probability. Previous efforts to incorporate such autocorrelation have largely focused on logit-normal formulations for occupancy, with spatial autocorrelation induced by a random effect within a hierarchical modeling framework. Although useful, computational time generally limits such an approach to relatively small data sets, and there are often problems with algorithm instability, yielding unsatisfactory results. Further, recent research has revealed a hidden form of multicollinearity in such applications, which may lead to parameter bias if not explicitly addressed. Combining several techniques, we present a unifying hierarchical spatial occupancy model specification that is particularly effective over large spatial extents. This approach employs a probit mixture framework for occupancy and can easily accommodate a reduced-dimensional spatial process to resolve issues with multicollinearity and spatial confounding while improving algorithm convergence. Using open-source software, we demonstrate this new model specification using a case study involving occupancy of caribou (Rangifer tarandus) over a set of 1080 survey units spanning a large contiguous region (108 000 km2) in northern Ontario, Canada. Overall, the combination of a more efficient specification and open-source software allows for a facile and stable implementation of spatial occupancy models for large data sets.

  20. Large Representation Recurrences in Large N Random Unitary Matrix Models

    CERN Document Server

    Karczmarek, Joanna L

    2011-01-01

    In a random unitary matrix model at large N, we study the properties of the expectation value of the character of the unitary matrix in the rank k symmetric tensor representation. We address the problem of whether the standard semiclassical technique for solving the model in the large N limit can be applied when the representation is very large, with k of order N. We find that the eigenvalues do indeed localize on an extremum of the effective potential; however, for finite but sufficiently large k/N, it is not possible to replace the discrete eigenvalue density with a continuous one. Nonetheless, the expectation value of the character has a well-defined large N limit, and when the discreteness of the eigenvalues is properly accounted for, it shows an intriguing approximate periodicity as a function of k/N.

  1. Modeling fault among motorcyclists involved in crashes.

    Science.gov (United States)

    Haque, Md Mazharul; Chin, Hoong Chor; Huang, Helai

    2009-03-01

    Singapore crash statistics from 2001 to 2006 show that the motorcyclist fatality and injury rates per registered vehicle are higher than those of other motor vehicles by 13 and 7 times, respectively. The crash involvement rate of motorcyclists as victims of other road users is also about 43%. The objective of this study is to identify the factors that contribute to the fault of motorcyclists involved in crashes. This is done by using the binary logit model to differentiate between at-fault and not-at-fault cases and the analysis is further categorized by the location of the crashes, i.e., at intersections, on expressways and at non-intersections. A number of explanatory variables representing roadway characteristics, environmental factors, motorcycle descriptions, and rider demographics have been evaluated. Time trend effect shows that not-at-fault crash involvement of motorcyclists has increased with time. The likelihood of night time crashes has also increased for not-at-fault crashes at intersections and expressways. The presence of surveillance cameras is effective in reducing not-at-fault crashes at intersections. Wet-road surfaces increase at-fault crash involvement at non-intersections. At intersections, not-at-fault crash involvement is more likely on single-lane roads or on median lane of multi-lane roads, while on expressways at-fault crash involvement is more likely on the median lane. Roads with higher speed limit have higher at-fault crash involvement and this is also true on expressways. Motorcycles with pillion passengers or with higher engine capacity have higher likelihood of being at-fault in crashes on expressways. Motorcyclists are more likely to be at-fault in collisions involving pedestrians and this effect is higher at night. In multi-vehicle crashes, motorcyclists are more likely to be victims than at-fault. Young and older riders are more likely to be at-fault in crashes than middle-aged group of riders. The findings of this study will help

  2. 大规模风电接入下含大用户直购电的电力系统调度模型研究%An Analysis Model of Power System With Large-scale Wind Power and Transaction Mode of Direct Power Purchase by Large Consumers Involved in System Scheduling

    Institute of Scientific and Technical Information of China (English)

    张文韬; 王秀丽; 吴雄; 姚力

    2015-01-01

    ABSTRACT:Large-scale integration of wind power makes the peak regulation become more and more complex. At the same time, the influence on power system by carrying out the transaction mode of direct power purchase by large consumers is still urgently needed to research because this transaction mode is a key link of innovation in electric power market to introduce competition in the retail side. Therefore, depending on the attention degree of wind power the decision makers pay, two system scheduling models with this transaction mode involved in were set up. Those were comprehensive benefits priority scheduling model and wind power priority scheduling model. These two models both aimed to maximum the expected profit of power generation system considering the randomness of the wind power output. Then auto-regressive and moving average (ARMA) model and Monte Carlo technique were taken to simulate a large number of wind power scenarios, and scenario reduction algorithm is developed to get a finite number of representative scenarios. Also, peak and valley time price was considered and mixed integer programming technique were used to obtain the operational aspects of every unit and the arrangement of the power directly purchased by the large consumers in all scenarios. What’s more, the economic and running benefits of this transaction mode could also be calculated using above methods. Test system is used to verify the rationality and feasibility of the proposed models and algorithm.%大规模风电的接入使得电力系统的调峰问题愈发复杂。与此同时,作为电力市场改革进程中开放售电侧竞争的重要环节,开展大用户直购电对系统调度与运行的影响仍亟待研究。对此,依据决策者对于风电重视程度的不同建立两种包含大用户直购电的调度模型,分别为风电效益权衡模型和风电优先调度模型。模型均以最大化发电系统运行期望效益为目标,

  3. Structuring very large domain models

    DEFF Research Database (Denmark)

    Störrle, Harald

    2010-01-01

    View/Viewpoint approaches like IEEE 1471-2000, or Kruchten's 4+1-view model are used to structure software architectures at a high level of granularity. While research has focused on architectural languages and with consistency between multiple views, practical questions such as the structuring a...

  4. Very Large System Dynamics Models - Lessons Learned

    Energy Technology Data Exchange (ETDEWEB)

    Jacob J. Jacobson; Leonard Malczynski

    2008-10-01

    This paper provides lessons learned from developing several large system dynamics (SD) models. System dynamics modeling practice emphasize the need to keep models small so that they are manageable and understandable. This practice is generally reasonable and prudent; however, there are times that large SD models are necessary. This paper outlines two large SD projects that were done at two Department of Energy National Laboratories, the Idaho National Laboratory and Sandia National Laboratories. This paper summarizes the models and then discusses some of the valuable lessons learned during these two modeling efforts.

  5. DYNAMIC SIMULATION OF FLUID-STRUCTURE INTERACTION PROBLEMS INVOLVING LARGE-AMPLITUDE SLOSHING

    Institute of Scientific and Technical Information of China (English)

    Chen Jianping; Zhou Rurong; Wu Wenlong

    2004-01-01

    An effective computational method is developed for dynamic analysis of fluid-structure interaction problems involving large-amplitude sloshing of the fluid and large-displacement motion of the structure.The structure is modeled as a rigid container supported by a system consisting of springs and dashpots.The motion of the fluid is decomposed into two parts: the large-displacement motion with the container and the large-amplitude sloshing relative to the container.The former is conveniently dealt with by defining a container-fixed noninertial local frame, while the latter is easily handled by adopting an ALE kinematical description.This leads to an easy and accurate treatment of both the fluid-structure interface and the fluid free surface without producing excessive distortion of the computational mesh.The coupling between the fluid and the structure is accomplished through the coupling matrices that can be easily established.Two numerical examples, including a TLD-structure system and a simplified liquid-loaded vehicle system, are presented to demonstrate the effectiveness and reliability of the proposed method.The present work can also be applied to simulate fluid-structure problems incorporating multibody systems and several fluid domains.

  6. Large Scale Computations in Air Pollution Modelling

    DEFF Research Database (Denmark)

    Zlatev, Z.; Brandt, J.; Builtjes, P. J. H.

    Proceedings of the NATO Advanced Research Workshop on Large Scale Computations in Air Pollution Modelling, Sofia, Bulgaria, 6-10 July 1998......Proceedings of the NATO Advanced Research Workshop on Large Scale Computations in Air Pollution Modelling, Sofia, Bulgaria, 6-10 July 1998...

  7. Large Scale Computations in Air Pollution Modelling

    DEFF Research Database (Denmark)

    Zlatev, Z.; Brandt, J.; Builtjes, P. J. H.

    Proceedings of the NATO Advanced Research Workshop on Large Scale Computations in Air Pollution Modelling, Sofia, Bulgaria, 6-10 July 1998......Proceedings of the NATO Advanced Research Workshop on Large Scale Computations in Air Pollution Modelling, Sofia, Bulgaria, 6-10 July 1998...

  8. Composite model with large mixing of neutrinos

    CERN Document Server

    Haba, N

    1999-01-01

    We suggest a simple composite model that induces the large flavor mixing of neutrino in the supersymmetric theory. This model has only one hyper-color in addition to the standard gauge group, which makes composite states of preons. In this model, {\\bf 10} and {\\bf 1} representations in SU(5) grand unified theory are composite states and produce the mass hierarchy. This explains why the large mixing is realized in the lepton sector, while the small mixing is realized in the quark sector. This model can naturally solve the atmospheric neutrino problem. We can also solve the solar neutrino problem by improving the model.

  9. Refactoring Process Models in Large Process Repositories.

    NARCIS (Netherlands)

    Weber, B.; Reichert, M.U.

    2008-01-01

    With the increasing adoption of process-aware information systems (PAIS), large process model repositories have emerged. Over time respective models have to be re-aligned to the real-world business processes through customization or adaptation. This bears the risk that model redundancies are introdu

  10. Refactoring Process Models in Large Process Repositories.

    NARCIS (Netherlands)

    Weber, B.; Reichert, M.U.

    With the increasing adoption of process-aware information systems (PAIS), large process model repositories have emerged. Over time respective models have to be re-aligned to the real-world business processes through customization or adaptation. This bears the risk that model redundancies are

  11. Modeling human operator involvement in robotic systems

    NARCIS (Netherlands)

    Wewerinke, P.H.

    1991-01-01

    A modeling approach is presented to describe complex manned robotic systems. The robotic system is modeled as a (highly) nonlinear, possibly time-varying dynamic system including any time delays in terms of optimal estimation, control and decision theory. The role of the human operator(s) is modeled

  12. Large field excursions from a few site relaxion model

    Science.gov (United States)

    Fonseca, N.; de Lima, L.; Machado, C. S.; Matheus, R. D.

    2016-07-01

    Relaxion models are an interesting new avenue to explain the radiative stability of the Standard Model scalar sector. They require very large field excursions, which are difficult to generate in a consistent UV completion and to reconcile with the compact field space of the relaxion. We propose an N -site model which naturally generates the large decay constant needed to address these issues. Our model offers distinct advantages with respect to previous proposals: the construction involves non-Abelian fields, allowing for controlled high-energy behavior and more model building possibilities, both in particle physics and inflationary models, and also admits a continuum limit when the number of sites is large, which may be interpreted as a warped extra dimension.

  13. Buried Waste Integrated Demonstration stakeholder involvement model

    Energy Technology Data Exchange (ETDEWEB)

    Kaupanger, R.M.; Kostelnik, K.M.; Milam, L.M.

    1994-04-01

    The Buried Waste Integrated Demonstration (BWID) is a program funded by the US Department of Energy (DOE) Office of Technology Development. BWID supports the applied research, development, demonstration, and evaluation of a suite of advanced technologies that together form a comprehensive remediation system for the effective and efficient remediation of buried waste. Stakeholder participation in the DOE Environmental Management decision-making process is critical to remediation efforts. Appropriate mechanisms for communication with the public, private sector, regulators, elected officials, and others are being aggressively pursued by BWID to permit informed participation. This document summarizes public outreach efforts during FY-93 and presents a strategy for expanded stakeholder involvement during FY-94.

  14. LARGE SIGNAL DISCRETE-TIME MODEL FOR PARALLELED BUCK CONVERTERS

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    As a number of switch-combinations are involved in operation of multi-converter-system, conventional methods for obtaining discrete-time large signal model of these converter systems result in a very complex solution. A simple sampled-data technique for modeling distributed dc-dc PWM converters system (DCS) was proposed. The resulting model is nonlinear and can be linearized for analysis and design of DCS. These models are also suitable for fast simulation of these networks. As the input and output of dc-dc converters are slow varying, suitable model for DCS was obtained in terms of the finite order input/output approximation.

  15. Laboratory Modeling of Aspects of Large Fires,

    Science.gov (United States)

    1984-04-30

    7 -7 g~L AD-A153 152 DNA-TR- 84-18 LABORATORY MODELING OF ASPECTS OF LARGE FIRES G.F. Carrier "URARY F.E. Fendell b DVSO R.D. Fleeter N. Got L.M...I1I TITLE (include Socurty Olassihicarion) LABORATORY MODELING OF ASPECTS OF LARGE FIRES 12. PERSONAL AUrHoR(S G.F. Carrier F.E. Fendell R.D. Fleeter N...Motorbuch Verlag.___ Caidin, M. (1960). A Torch to the Enemy: the Fire Raid on Tokyo. New York, NY: Ballantine. Carrier, G. F., Fendell , F. E., and

  16. Large scale topic modeling made practical

    DEFF Research Database (Denmark)

    Wahlgreen, Bjarne Ørum; Hansen, Lars Kai

    2011-01-01

    Topic models are of broad interest. They can be used for query expansion and result structuring in information retrieval and as an important component in services such as recommender systems and user adaptive advertising. In large scale applications both the size of the database (number of docume......Topic models are of broad interest. They can be used for query expansion and result structuring in information retrieval and as an important component in services such as recommender systems and user adaptive advertising. In large scale applications both the size of the database (number...... topics at par with a much larger case specific vocabulary....

  17. Modeling capillary forces for large displacements

    NARCIS (Netherlands)

    Mastrangeli, M.; Arutinov, G.; Smits, E.C.P.; Lambert, P.

    2014-01-01

    Originally applied to the accurate, passive positioning of submillimetric devices, recent works proved capillary self-alignment as effective also for larger components and relatively large initial offsets. In this paper, we describe an analytic quasi-static model of 1D capillary restoring forces tha

  18. Pronunciation Modeling for Large Vocabulary Speech Recognition

    Science.gov (United States)

    Kantor, Arthur

    2010-01-01

    The large pronunciation variability of words in conversational speech is one of the major causes of low accuracy in automatic speech recognition (ASR). Many pronunciation modeling approaches have been developed to address this problem. Some explicitly manipulate the pronunciation dictionary as well as the set of the units used to define the…

  19. Inverse modeling for Large-Eddy simulation

    NARCIS (Netherlands)

    Geurts, Bernardus J.

    1998-01-01

    Approximate higher order polynomial inversion of the top-hat filter is developed with which the turbulent stress tensor in Large-Eddy Simulation can be consistently represented using the filtered field. Generalized (mixed) similarity models are proposed which improved the agreement with the kinetic

  20. Computational Modeling of Large Wildfires: A Roadmap

    KAUST Repository

    Coen, Janice L.

    2010-08-01

    Wildland fire behavior, particularly that of large, uncontrolled wildfires, has not been well understood or predicted. Our methodology to simulate this phenomenon uses high-resolution dynamic models made of numerical weather prediction (NWP) models coupled to fire behavior models to simulate fire behavior. NWP models are capable of modeling very high resolution (< 100 m) atmospheric flows. The wildland fire component is based upon semi-empirical formulas for fireline rate of spread, post-frontal heat release, and a canopy fire. The fire behavior is coupled to the atmospheric model such that low level winds drive the spread of the surface fire, which in turn releases sensible heat, latent heat, and smoke fluxes into the lower atmosphere, feeding back to affect the winds directing the fire. These coupled dynamic models capture the rapid spread downwind, flank runs up canyons, bifurcations of the fire into two heads, and rough agreement in area, shape, and direction of spread at periods for which fire location data is available. Yet, intriguing computational science questions arise in applying such models in a predictive manner, including physical processes that span a vast range of scales, processes such as spotting that cannot be modeled deterministically, estimating the consequences of uncertainty, the efforts to steer simulations with field data ("data assimilation"), lingering issues with short term forecasting of weather that may show skill only on the order of a few hours, and the difficulty of gathering pertinent data for verification and initialization in a dangerous environment. © 2010 IEEE.

  1. An economic model of large Medicaid practices.

    Science.gov (United States)

    Cromwell, J; Mitchell, J B

    1984-06-01

    Public attention given to Medicaid "mills" prompted this more general investigation of the origins of large Medicaid practices. A dual market demand model is proposed showing how Medicaid competes with private insurers for scarce physician time. Various program parameters--fee schedules, coverage, collection costs--are analyzed along with physician preferences, specialties, and other supply-side characteristics. Maximum likelihood techniques are used to test the model. The principal finding is that in raising Medicaid fees, as many physicians opt into the program as expand their Medicaid caseloads to exceptional levels, leaving the maldistribution of patients unaffected while notably improving access. Still, the fact that Medicaid fees are lower than those of private insurers does lead to reduced access to more qualified practitioners. Where anti-Medicaid sentiment is stronger, access is also reduced and large Medicaid practices more likely to flourish.

  2. Engineering large animal models of human disease.

    Science.gov (United States)

    Whitelaw, C Bruce A; Sheets, Timothy P; Lillico, Simon G; Telugu, Bhanu P

    2016-01-01

    The recent development of gene editing tools and methodology for use in livestock enables the production of new animal disease models. These tools facilitate site-specific mutation of the genome, allowing animals carrying known human disease mutations to be produced. In this review, we describe the various gene editing tools and how they can be used for a range of large animal models of diseases. This genomic technology is in its infancy but the expectation is that through the use of gene editing tools we will see a dramatic increase in animal model resources available for both the study of human disease and the translation of this knowledge into the clinic. Comparative pathology will be central to the productive use of these animal models and the successful translation of new therapeutic strategies.

  3. Iron Malabsorption in a Patient With Large Cell Lymphoma Involving the Duodenum

    Science.gov (United States)

    1992-01-01

    111-37. coeliac disease . Lancet 1960:1:192-4. 7. Shreeve DR. Horrocks P. Mainwaring AR. Steatorrhea and intra- 20. Green PA. Wollaeger EE. The clinical...compounded the anemia in a pa- tion in celiac disease were reversible by the institution tient with diffuse large cell lymphoma involving the of a gluten...hemoglobin. The lymphomas (5-7). The presenting symptoms mimic chest radiograph in May demonstrated an anterior me- those of celiac disease and include

  4. Endoscopic submucosal dissection for large laterally spreading tumors involving the ileocecal valve and terminal ileum

    Institute of Scientific and Technical Information of China (English)

    Gustavo Kishimoto; Yutaka Saito; Hajime Takisawa; Haruhisa Suzuki; Taku Sakamoto; Takeshi Nakajima; Takahisa Matsuda

    2012-01-01

    Endoscopic submucosal dissection is a challenging technique that enables en-bloc resection for large colorectal tumors, as laterally spreading tumors, particularly difficult, if the ileocecal valve and terminal ileum is involved. Herein, we report on one of 4 cases. The procedures, using a bipolar needle knife (B-Knife) to reduce the perforation risk and carbon dioxide instead of conventional air insufflation for patient comfort, achieved curative resections without any complications.

  5. Large-scale multimedia modeling applications

    Energy Technology Data Exchange (ETDEWEB)

    Droppo, J.G. Jr.; Buck, J.W.; Whelan, G.; Strenge, D.L.; Castleton, K.J.; Gelston, G.M.

    1995-08-01

    Over the past decade, the US Department of Energy (DOE) and other agencies have faced increasing scrutiny for a wide range of environmental issues related to past and current practices. A number of large-scale applications have been undertaken that required analysis of large numbers of potential environmental issues over a wide range of environmental conditions and contaminants. Several of these applications, referred to here as large-scale applications, have addressed long-term public health risks using a holistic approach for assessing impacts from potential waterborne and airborne transport pathways. Multimedia models such as the Multimedia Environmental Pollutant Assessment System (MEPAS) were designed for use in such applications. MEPAS integrates radioactive and hazardous contaminants impact computations for major exposure routes via air, surface water, ground water, and overland flow transport. A number of large-scale applications of MEPAS have been conducted to assess various endpoints for environmental and human health impacts. These applications are described in terms of lessons learned in the development of an effective approach for large-scale applications.

  6. Isolated cutaneous involvement in a child with nodal anaplastic large cell lymphoma

    Directory of Open Access Journals (Sweden)

    Vibhu Mendiratta

    2016-01-01

    Full Text Available Non-Hodgkin lymphoma is a common childhood T-cell and B-cell neoplasm that originates primarily from lymphoid tissue. Cutaneous involvement can be in the form of a primary extranodal lymphoma, or secondary to metastasis from a non-cutaneous location. The latter is uncommon, and isolated cutaneous involvement is rarely reported. We report a case of isolated secondary cutaneous involvement from nodal anaplastic large cell lymphoma (CD30 + and ALK + in a 7-year-old boy who was on chemotherapy. This case is reported for its unusual clinical presentation as an acute febrile, generalized papulonodular eruption that mimicked deep fungal infection, with the absence of other foci of systemic metastasis.

  7. ALK-positive anaplastic large cell lymphoma with soft tissue involvement in a young woman

    Directory of Open Access Journals (Sweden)

    Gao KH

    2016-07-01

    Full Text Available Kehai Gao, Hongtao Li, Caihong Huang, Huazhuang Li, Jun Fang, Chen Tian Department of Orthopaedics, Yidu Central Hospital, Shandong, People’s Republic of China Introduction: Anaplastic large cell lymphoma (ALCL is a type of non-Hodgkin lymphoma that has strong expression of CD30. ALCL can sometimes involve the bone marrow, and in advanced stages, it can produce destructive extranodal lesions. But anaplastic large cell lymphoma kinase (ALK+ ALCL with soft tissue involvement is very rare.Case report: A 35-year-old woman presented with waist pain for over 1 month. The biopsy of soft tissue lesions showed that these cells were positive for ALK-1, CD30, TIA-1, GranzymeB, CD4, CD8, and Ki67 (90%+ and negative for CD3, CD5, CD20, CD10, cytokeratin (CK, TdT, HMB-45, epithelial membrane antigen (EMA, and pan-CK, which identified ALCL. After six cycles of Hyper-CVAD/MA regimen, she achieved partial remission. Three months later, she died due to disease progression.Conclusion: This case illustrates the unusual presentation of ALCL in soft tissue with a bad response to chemotherapy. Because of the tendency for rapid progression, ALCL in young adults with extranodal lesions are often treated with high-grade chemotherapy, such as Hyper-CVAD/MA. Keywords: anaplastic large cell lymphoma, ALK+, soft tissue involvement, Hyper-CVAD/MA

  8. Large genetic animal models of Huntington's Disease.

    Science.gov (United States)

    Morton, A Jennifer; Howland, David S

    2013-01-01

    The dominant nature of the Huntington's disease gene mutation has allowed genetic models to be developed in multiple species, with the mutation causing an abnormal neurological phenotype in all animals in which it is expressed. Many different rodent models have been generated. The most widely used of these, the transgenic R6/2 mouse, carries the mutation in a fragment of the human huntingtin gene and has a rapidly progressive and fatal neurological phenotype with many relevant pathological changes. Nevertheless, their rapid decline has been frequently questioned in the context of a disease that takes years to manifest in humans, and strenuous efforts have been made to make rodent models that are genetically more 'relevant' to the human condition, including full length huntingtin gene transgenic and knock-in mice. While there is no doubt that we have learned, and continue to learn much from rodent models, their usefulness is limited by two species constraints. First, the brains of rodents differ significantly from humans in both their small size and their neuroanatomical organization. Second, rodents have much shorter lifespans than humans. Here, we review new approaches taken to these challenges in the development of models of Huntington's disease in large brained, long-lived animals. We discuss the need for such models, and how they might be used to fill specific niches in preclinical Huntington's disease research, particularly in testing gene-based therapeutics. We discuss the advantages and disadvantages of animals in which the prodromal period of disease extends over a long time span. We suggest that there is considerable 'value added' for large animal models in preclinical Huntington's disease research.

  9. Identifiability of large phylogenetic mixture models.

    Science.gov (United States)

    Rhodes, John A; Sullivant, Seth

    2012-01-01

    Phylogenetic mixture models are statistical models of character evolution allowing for heterogeneity. Each of the classes in some unknown partition of the characters may evolve by different processes, or even along different trees. Such models are of increasing interest for data analysis, as they can capture the variety of evolutionary processes that may be occurring across long sequences of DNA or proteins. The fundamental question of whether parameters of such a model are identifiable is difficult to address, due to the complexity of the parameterization. Identifiability is, however, essential to their use for statistical inference.We analyze mixture models on large trees, with many mixture components, showing that both numerical and tree parameters are indeed identifiable in these models when all trees are the same. This provides a theoretical justification for some current empirical studies, and indicates that extensions to even more mixture components should be theoretically well behaved. We also extend our results to certain mixtures on different trees, using the same algebraic techniques.

  10. Large animal models for stem cell therapy.

    Science.gov (United States)

    Harding, John; Roberts, R Michael; Mirochnitchenko, Oleg

    2013-03-28

    The field of regenerative medicine is approaching translation to clinical practice, and significant safety concerns and knowledge gaps have become clear as clinical practitioners are considering the potential risks and benefits of cell-based therapy. It is necessary to understand the full spectrum of stem cell actions and preclinical evidence for safety and therapeutic efficacy. The role of animal models for gaining this information has increased substantially. There is an urgent need for novel animal models to expand the range of current studies, most of which have been conducted in rodents. Extant models are providing important information but have limitations for a variety of disease categories and can have different size and physiology relative to humans. These differences can preclude the ability to reproduce the results of animal-based preclinical studies in human trials. Larger animal species, such as rabbits, dogs, pigs, sheep, goats, and non-human primates, are better predictors of responses in humans than are rodents, but in each case it will be necessary to choose the best model for a specific application. There is a wide spectrum of potential stem cell-based products that can be used for regenerative medicine, including embryonic and induced pluripotent stem cells, somatic stem cells, and differentiated cellular progeny. The state of knowledge and availability of these cells from large animals vary among species. In most cases, significant effort is required for establishing and characterizing cell lines, comparing behavior to human analogs, and testing potential applications. Stem cell-based therapies present significant safety challenges, which cannot be addressed by traditional procedures and require the development of new protocols and test systems, for which the rigorous use of larger animal species more closely resembling human behavior will be required. In this article, we discuss the current status and challenges of and several major directions

  11. Development of large Area Covering Height Model

    Science.gov (United States)

    Jacobsen, K.

    2014-04-01

    Height information is a basic part of topographic mapping. Only in special areas frequent update of height models is required, usually the update cycle is quite lower as for horizontal map information. Some height models are available free of charge in the internet; for commercial height models a fee has to be paid. Mostly digital surface models (DSM) with the height of the visible surface are given and not the bare ground height, as required for standard mapping. Nevertheless by filtering of DSM, digital terrain models (DTM) with the height of the bare ground can be generated with the exception of dense forest areas where no height of the bare ground is available. These height models may be better as the DTM of some survey administrations. In addition several DTM from national survey administrations are classified, so as alternative the commercial or free of charge available information from internet can be used. The widely used SRTM DSM is available also as ACE-2 GDEM corrected by altimeter data for systematic height errors caused by vegetation and orientation errors. But the ACE-2 GDEM did not respect neighbourhood information. With the worldwide covering TanDEM-X height model, distributed starting 2014 by Airbus Defence and Space (former ASTRIUM) as WorldDEM, higher level of details and accuracy is reached as with other large area covering height models. At first the raw-version of WorldDEM will be available, followed by an edited version and finally as WorldDEM-DTM a height model of the bare ground. With 12 m spacing and a relative standard deviation of 1.2 m within an area of 1° x 1° an accuracy and resolution level is reached, satisfying also for larger map scales. For limited areas with the HDEM also a height model with 6 m spacing and a relative vertical accuracy of 0.5 m can be generated on demand. By bathymetric LiDAR and stereo images also the height of the sea floor can be determined if the water has satisfying transparency. Another method of getting

  12. Combinatorial Model Involving Stochastic Choices of Destination, Mode and Route

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Traffic assignment models are one of the basic tools for the analysis and design of transportation systems. However, the existing models have some defects. Considering the characteristics of Chinese urban mixed traffic and the randomness of transportation information, the author develops a combinatorial model involving stochastic choices of destination, mode and route. Its uniqueness and equivalance are also proved by the optimization theory.

  13. Clearance of bacteria and differential involvement of mussel hyalinocytes, small and large granulocytes in antibacterial immunity

    DEFF Research Database (Denmark)

    Jouvet, Lionel

    2008-01-01

    and more than 48 h for Vibrio anguillarum. The total hemocyte count (THC) was dramatically lowered by the bacterial injections, as quantified by flow cytometry. V. splendidus induced the strongest decreases with -66% 9h post-injection of living bacteria and -56% 3h post-injection of heat-killed bacteria....... Flow cytometry was used to identify three main sub-populations of hemocytes, namely hyalinocytes, small granulocytes and large granulocytes. When THC was minimal, i.e. within the first 9h post-injection, proportions of the three cell categories varied dramatically, suggesting differential involvement...

  14. Five challenges for stochastic epidemic models involving global transmission

    Directory of Open Access Journals (Sweden)

    Tom Britton

    2015-03-01

    Full Text Available The most basic stochastic epidemic models are those involving global transmission, meaning that infection rates depend only on the type and state of the individuals involved, and not on their location in the population. Simple as they are, there are still several open problems for such models. For example, when will such an epidemic go extinct and with what probability (questions depending on the population being fixed, changing or growing? How can a model be defined explaining the sometimes observed scenario of frequent mid-sized epidemic outbreaks? How can evolution of the infectious agent transmission rates be modelled and fitted to data in a robust way?

  15. High Frequency of Bone Marrow Involvement in Intravascular Large B-Cell Lymphoma.

    Science.gov (United States)

    Wang, Jianchao; Ding, Wenshuang; Gao, Limin; Yao, Wenqing; Chen, Min; Zhao, Sha; Liu, Weiping; Zhang, Wenyan

    2017-04-01

    Intravascular large B-cell lymphoma (IVLBCL) is a rare subtype of diffuse large B-cell lymphoma. Thirteen cases of IVLBCL with a median age of 56 years were analyzed retrospectively. Nonspecific symptoms such as fever and hepatosplenomegaly were the most common manifestations, and the bone marrow was usually involved in 8/13 (61.5%) cases. All tumors expressed CD20, and 12/13 (92.3%) of the tumors exhibited a nongerminal center phenotype by Hans algorithm. CD5 was expressed in 3/12 (25%) of the tumors. MYC was negative in all cases, and BCL2 was positive in 10/12 (83.3%) cases. Cytogenetic analysis revealed 5 cases that did not have rearrangements in either the MYC or the BCL2 gene. No association with Epstein-Barr virus was found. Seven of 11 patients received chemotherapy. The median survival time was 6 months. Patients with hemophagocytic syndrome had poor prognoses. Our study demonstrates that IVLBCL has a poor clinical outcome with a high frequency of bone marrow involvement and that the MYC gene may not play an important role in the poor prognosis of IVLBCL.

  16. Diffuse large B-cell lymphoma involving the central nervous system.

    Science.gov (United States)

    Gualco, Gabriela; Weiss, Lawrence M; Barber, Glen N; Bacchi, Carlos E

    2011-02-01

    Lymphomas involving the central nervous system are recognized increasingly in immunocompetent as well as immunosuppressed individuals, and the majority of the cases are diffuse large B-cell lymphoma (DLBCL). The aim of this study was to compare the immunophenotype, clinicopathological features, and association with Epstein-Barr virus (EBV) of DLBCL of the central nervous system (CNS) in 3 different clinical situations: primary, in immunocompetent patients; "primary," in immunosuppressed patients; and in patients with secondary involvement by systemic lymphoma. The authors reviewed the clinicopathological features, morphology, immunophenotype (according to germinal-center B-cell-like and nongerminal B-cell-like subtypes), and association with EBV in 36 cases of DLBCL of the CNS, including 25 primary cases, 5 associated with immunosuppression, and 6 cases with secondary involvement. Survival was evaluated in 15 cases of primary CNS lymphomas. Of the 36 patients, 19 were male and 18 female. Only 2 cases of lymphomas were EBV-positive; both occurred in immunosuppressed patients. Separation into germinal-center and non-germinal center subtypes by an immunohistochemistry panel showed that 68% of primary, 80% of secondary, and 83% of the cases associated with immunosuppression were of non-germinal-center subtype, respectively. Patients with non-germinal-center immunophenotype showed significantly worse survival than those with CNS lymphomas of the germinal-center subtype.

  17. Comparing the performance of SIMD computers by running large air pollution models

    DEFF Research Database (Denmark)

    Brown, J.; Hansen, Per Christian; Wasniewski, J.

    1996-01-01

    To compare the performance and use of three massively parallel SIMD computers, we implemented a large air pollution model on these computers. Using a realistic large-scale model, we gained detailed insight about the performance of the computers involved when used to solve large-scale scientific...... problems that involve several types of numerical computations. The computers used in our study are the Connection Machines CM-200 and CM-5, and the MasPar MP-2216...

  18. A consumer involvement model for health technology assessment in Canada.

    Science.gov (United States)

    Pivik, Jayne; Rode, Elisabeth; Ward, Christopher

    2004-08-01

    Similar to other health policy initiatives, there is a growing movement to involve consumers in decisions affecting their treatment options. Access to treatments can be impacted by decisions made during a health technology assessment (HTA), i.e., the rigorous assessment of medical interventions such as drugs, vaccines, devices, materials, medical and surgical procedures and systems. The purpose of this paper was to empirically assess the interest and potential mechanisms for consumer involvement in HTA by identifying what health consumer organizations consider meaningful involvement, examining current practices internationally and developing a model for involvement based on identified priorities and needs. Canadian health consumer groups representing the largest disease or illness conditions reported a desire for involvement in HTA and provided feedback on mechanisms for facilitating their involvement.

  19. Modeling of large area hot embossing

    CERN Document Server

    Worgull, M; Marcotte, J -P; Hétu, J -F; Heckele, M

    2008-01-01

    Today, hot embossing and injection molding belong to the established plastic molding processes in microengineering. Based on experimental findings, a variety of microstructures have been replicated so far using the processes. However, with increasing requirements regarding the embossing surface and the simultaneous decrease of the structure size down into the nanorange, increasing know-how is needed to adapt hot embossing to industrial standards. To reach this objective, a German-Canadian cooperation project has been launched to study hot embossing theoretically by a process simulation and experimentally. The present publication shall report about the first results of the simulation - the modeling and simulation of large area replication based on an eight inch microstructured mold.

  20. Large Scale, High Resolution, Mantle Dynamics Modeling

    Science.gov (United States)

    Geenen, T.; Berg, A. V.; Spakman, W.

    2007-12-01

    To model the geodynamic evolution of plate convergence, subduction and collision and to allow for a connection to various types of observational data, geophysical, geodetical and geological, we developed a 4D (space-time) numerical mantle convection code. The model is based on a spherical 3D Eulerian fem model, with quadratic elements, on top of which we constructed a 3D Lagrangian particle in cell(PIC) method. We use the PIC method to transport material properties and to incorporate a viscoelastic rheology. Since capturing small scale processes associated with localization phenomena require a high resolution, we spend a considerable effort on implementing solvers suitable to solve for models with over 100 million degrees of freedom. We implemented Additive Schwartz type ILU based methods in combination with a Krylov solver, GMRES. However we found that for problems with over 500 thousend degrees of freedom the convergence of the solver degraded severely. This observation is known from the literature [Saad, 2003] and results from the local character of the ILU preconditioner resulting in a poor approximation of the inverse of A for large A. The size of A for which ILU is no longer usable depends on the condition of A and on the amount of fill in allowed for the ILU preconditioner. We found that for our problems with over 5×105 degrees of freedom convergence became to slow to solve the system within an acceptable amount of walltime, one minute, even when allowing for considerable amount of fill in. We also implemented MUMPS and found good scaling results for problems up to 107 degrees of freedom for up to 32 CPU¡¯s. For problems with over 100 million degrees of freedom we implemented Algebraic Multigrid type methods (AMG) from the ML library [Sala, 2006]. Since multigrid methods are most effective for single parameter problems, we rebuild our model to use the SIMPLE method in the Stokes solver [Patankar, 1980]. We present scaling results from these solvers for 3D

  1. Transactional Models Between Personality and Alcohol Involvement: A Further Examination

    OpenAIRE

    2012-01-01

    Although correlated changes between personality and alcohol involvement have been shown, the functional relation between these constructs is also of theoretical and clinical interest. Using bivariate latent difference score models, we examined transactional relations (i.e., personality predicting changes in alcohol involvement, which in turn predicts changes in personality) across two distinct but overlapping developmental time frames (i.e., across college and during young adulthood) using tw...

  2. Involvement of intracellular calcium stores during oxygen/glucose deprivation in striatal large aspiny interneurons.

    Science.gov (United States)

    Pisani, A; Bonsi, P; Centonze, D; Giacomini, P; Calabresi, P

    2000-05-01

    Striatal large aspiny interneurons were recorded from a slice preparation using a combined electrophysiologic and microfluorometric approach. The role of intracellular Ca2+ stores was analyzed during combined oxygen/glucose deprivation (OGD). Before addressing the role of the stores during energy deprivation, the authors investigated their function under physiologic conditions. Trains of depolarizing current pulses caused bursts of action potentials coupled to transient increases in intracellular calcium concentration ([Ca2+]i). In the presence of cyclopiazonic acid (30 micromol/L), a selective inhibitor of the sarcoendoplasmic reticulum Ca2+ pumps, or when ryanodine receptors were directly blocked with ryanodine (20 [micromol/L), the [Ca2+]i transients were progressively smaller in amplitude, suggesting that [Ca2+]i released from intracellular stores helps to maintain a critical level of [Ca2+]i during physiologic firing activity. As the authors have recently reported, brief exposure to combined OGD induced a membrane hyperpolarization coupled to an increase in [Ca2+]i. In the presence of cyclopiazonic acid or ryanodine, the hyperpolarization and the rise in [Ca2+]i induced by OGD were consistently reduced. These data support the hypothesis that Ca2+ release from ryanodine-sensitive Ca2+ pools is involved not only in the potentiation of the Ca2+ signals resulting from cell depolarization, but also in the amplification of the [Ca2+]i rise and of the concurrent membrane hyperpolarization observed in course of OGD in striatal large aspiny interneurons.

  3. Positive Solutions for a Competition Model with an Inhibitor Involved

    Institute of Scientific and Technical Information of China (English)

    Bin Chen

    2008-01-01

    In the paper, we study the positive solutions of a diffusive competition model with an inhibitor involved subject to the homogeneous Dirichlet boundary condition. The existence, uniqueness, stability and multiplicity of positive solutions are discussed. This is mainly done by using the local and global bifurcation theory.

  4. The contribution of advisory committees and public involvement to large studies: case study

    Directory of Open Access Journals (Sweden)

    Tew Jerry

    2010-12-01

    Full Text Available Abstract Background Many large studies have complex advisory committee structures, yet there is no empirical evidence regarding their optimal composition, scope and contribution. The aim of this study was to inform the committee and advice infrastructure for future research studies. Methods In the context of a five-year study funded by the UK National Institute for Health Research, three advisory committees were formed. In addition, advice was obtained from individual experts. All recommendations received in the start-up phase (first seven months of the study were recorded, along with the decision about implementation of the recommendation. A particular focus was on the impact of public involvement. Results A total of 172 recommendations were made, including 70 from 20 individual experts. The recommendations were grouped into five emergent themes: Scientific, Pragmatic, Resources, Committee and Collaboration. Most recommendations related to strengthening existing components or adding new components to the study protocol. Very few recommendations either proposed removing study components or contradicted other recommendations. Three 'implementation criteria' were identified: scientific value, pragmatic feasibility, and paradigmatic consistency. 103 (60% of recommendations were implemented and 25 (15% were not implemented. The benefits identified by the research team were improved quality and confidence, and the costs were increased cognitive demands, protocol revision time, and slower progress. Conclusions The findings are discussed in the context of the wider literature on public involvement in research. Six recommendations are identified. First, have a clear rationale for each advisory committee expressed as terms of reference, and consider the best balance between committees and individual consultation with experts. Second, an early concern of committees is inter-committee communication, so consider cross-representation and copying minutes

  5. Modelling large-scale evacuation of music festivals

    Directory of Open Access Journals (Sweden)

    E. Ronchi

    2016-05-01

    Full Text Available This paper explores the use of multi-agent continuous evacuation modelling for representing large-scale evacuation scenarios at music festivals. A 65,000 people capacity music festival area was simulated using the model Pathfinder. Three evacuation scenarios were developed in order to explore the capabilities of evacuation modelling during such incidents, namely (1 a preventive evacuation of a section of the festival area containing approximately 15,000 people due to a fire breaking out on a ship, (2 an escalating scenario involving the total evacuation of the entire festival area (65,000 people due to a bomb threat, and (3 a cascading scenario involving the total evacuation of the entire festival area (65,000 people due to the threat of an explosion caused by a ship engine overheating. This study suggests that the analysis of the people-evacuation time curves produced by evacuation models, coupled with a visual analysis of the simulated evacuation scenarios, allows for the identification of the main factors affecting the evacuation process (e.g., delay times, overcrowding at exits in relation to exit widths, etc. and potential measures that could improve safety.

  6. A Process Model of Organizational Commitment and Job Involvement.

    Science.gov (United States)

    1982-09-01

    AD-A123 043 A PROCESS MODEL OF ORGANIZATIONAL COMMITMENT AND JOB I INVOLVEMENT(U) AIR FORCE INST OF TECH WR IGHT PATTERSON AFB OH SCHOL OF SYSTEMS...Appo @1 inu pubo 01004 Aocesston For NTIS CRA&I DTIC TAB Unannounced 0I Justfication - gI, Distr" ’ut ioi / Af t A PROCESS MODEL OF ORGANIZATIONAL...GOVT ACCESSION NO. 3. RECIPIENT’S CATALOG NUMBER LSSR 76-82 1,3b - 4. TITLE (and Subtitle) S. TYPE OF REPORT & PERIOD COVERED A PROCESS MODEL OF

  7. Duct thermal performance models for large commercial buildings

    Energy Technology Data Exchange (ETDEWEB)

    Wray, Craig P.

    2003-10-01

    Despite the potential for significant energy savings by reducing duct leakage or other thermal losses from duct systems in large commercial buildings, California Title 24 has no provisions to credit energy-efficient duct systems in these buildings. A substantial reason is the lack of readily available simulation tools to demonstrate the energy-saving benefits associated with efficient duct systems in large commercial buildings. The overall goal of the Efficient Distribution Systems (EDS) project within the PIER High Performance Commercial Building Systems Program is to bridge the gaps in current duct thermal performance modeling capabilities, and to expand our understanding of duct thermal performance in California large commercial buildings. As steps toward this goal, our strategy in the EDS project involves two parts: (1) developing a whole-building energy simulation approach for analyzing duct thermal performance in large commercial buildings, and (2) using the tool to identify the energy impacts of duct leakage in California large commercial buildings, in support of future recommendations to address duct performance in the Title 24 Energy Efficiency Standards for Nonresidential Buildings. The specific technical objectives for the EDS project were to: (1) Identify a near-term whole-building energy simulation approach that can be used in the impacts analysis task of this project (see Objective 3), with little or no modification. A secondary objective is to recommend how to proceed with long-term development of an improved compliance tool for Title 24 that addresses duct thermal performance. (2) Develop an Alternative Calculation Method (ACM) change proposal to include a new metric for thermal distribution system efficiency in the reporting requirements for the 2005 Title 24 Standards. The metric will facilitate future comparisons of different system types using a common ''yardstick''. (3) Using the selected near-term simulation approach

  8. Environmental Management Model for Road Maintenance Operation Involving Community Participation

    Science.gov (United States)

    Triyono, A. R. H.; Setyawan, A.; Sobriyah; Setiono, P.

    2017-07-01

    Public expectations of Central Java, which is very high on demand fulfillment, especially road infrastructure as outlined in the number of complaints and community expectations tweeter, Short Mail Massage (SMS), e-mail and public reports from various media, Highways Department of Central Java province requires development model of environmental management in the implementation of a routine way by involving the community in order to fulfill the conditions of a representative, may serve road users safely and comfortably. This study used survey method with SEM analysis and SWOT with Latent Independent Variable (X), namely; Public Participation in the regulation, development, construction and supervision of road (PSM); Public behavior in the utilization of the road (PMJ) Provincial Road Service (PJP); Safety in the Provincial Road (KJP); Integrated Management System (SMT) and latent dependent variable (Y) routine maintenance of the provincial road that is integrated with the environmental management system and involve the participation of the community (MML). The result showed the implementation of routine maintenance of road conditions in Central Java province has yet to implement an environmental management by involving the community; Therefore developed environmental management model with the results of H1: Community Participation (PSM) has positive influence on the Model of Environmental Management (MML); H2: Behavior Society in Jalan Utilization (PMJ) positive effect on Model Environmental Management (MML); H3: Provincial Road Service (PJP) positive effect on Model Environmental Management (MML); H4: Safety in the Provincial Road (KJP) positive effect on Model Environmental Management (MML); H5: Integrated Management System (SMT) has positive influence on the Model of Environmental Management (MML). From the analysis obtained formulation model describing the relationship / influence of the independent variables PSM, PMJ, PJP, KJP, and SMT on the dependent variable

  9. Acquisition Integration Models: How Large Companies Successfully Integrate Startups

    Directory of Open Access Journals (Sweden)

    Peter Carbone

    2011-10-01

    Full Text Available Mergers and acquisitions (M&A have been popular means for many companies to address the increasing pace and level of competition that they face. Large companies have pursued acquisitions to more quickly access technology, markets, and customers, and this approach has always been a viable exit strategy for startups. However, not all deals deliver the anticipated benefits, in large part due to poor integration of the acquired assets into the acquiring company. Integration can greatly impact the success of the acquisition and, indeed, the combined company’s overall market success. In this article, I explore the implementation of several integration models that have been put into place by a large company and extract principles that may assist negotiating parties with maximizing success. This perspective may also be of interest to smaller companies as they explore exit options while trying to ensure continued market success after acquisition. I assert that business success with acquisitions is dependent on an appropriate integration model, but that asset integration is not formulaic. Any integration effort must consider the specific market context and personnel involved.

  10. Public involvement in breast cancer research: an analysis and model for future research.

    Science.gov (United States)

    McCormick, Sabrina; Brody, Julia; Brown, Phil; Polk, Ruth

    2004-01-01

    Public involvement in health program planning has been taking place for many years, and has provided a precedent for the emergence of public involvement in research conducted since the early 1990s. Such involvement is now widely seen in breast cancer research, due to the large public concern and major social movement activity. This article reviews current practices and general models of public involvement in research and constructs a prototype. The authors interviewed researchers, program officers, and laypeople in order to understand the obstacles, processes, and benefits. They conclude that public involvement has major ramifications for the democratization of science and the construction of knowledge by teaching lay people about science and sensitizing researchers to concerns of the public. There is growing support on the part of scientists and government agents for public involvement.

  11. Simulation of large-scale rule-based models

    Energy Technology Data Exchange (ETDEWEB)

    Hlavacek, William S [Los Alamos National Laboratory; Monnie, Michael I [Los Alamos National Laboratory; Colvin, Joshua [NON LANL; Faseder, James [NON LANL

    2008-01-01

    Interactions of molecules, such as signaling proteins, with multiple binding sites and/or multiple sites of post-translational covalent modification can be modeled using reaction rules. Rules comprehensively, but implicitly, define the individual chemical species and reactions that molecular interactions can potentially generate. Although rules can be automatically processed to define a biochemical reaction network, the network implied by a set of rules is often too large to generate completely or to simulate using conventional procedures. To address this problem, we present DYNSTOC, a general-purpose tool for simulating rule-based models. DYNSTOC implements a null-event algorithm for simulating chemical reactions in a homogenous reaction compartment. The simulation method does not require that a reaction network be specified explicitly in advance, but rather takes advantage of the availability of the reaction rules in a rule-based specification of a network to determine if a randomly selected set of molecular components participates in a reaction during a time step. DYNSTOC reads reaction rules written in the BioNetGen language which is useful for modeling protein-protein interactions involved in signal transduction. The method of DYNSTOC is closely related to that of STOCHSIM. DYNSTOC differs from STOCHSIM by allowing for model specification in terms of BNGL, which extends the range of protein complexes that can be considered in a model. DYNSTOC enables the simulation of rule-based models that cannot be simulated by conventional methods. We demonstrate the ability of DYNSTOC to simulate models accounting for multisite phosphorylation and multivalent binding processes that are characterized by large numbers of reactions. DYNSTOC is free for non-commercial use. The C source code, supporting documentation and example input files are available at .

  12. Involving stakeholders in building integrated fisheries models using Bayesian methods.

    Science.gov (United States)

    Haapasaari, Päivi; Mäntyniemi, Samu; Kuikka, Sakari

    2013-06-01

    A participatory Bayesian approach was used to investigate how the views of stakeholders could be utilized to develop models to help understand the Central Baltic herring fishery. In task one, we applied the Bayesian belief network methodology to elicit the causal assumptions of six stakeholders on factors that influence natural mortality, growth, and egg survival of the herring stock in probabilistic terms. We also integrated the expressed views into a meta-model using the Bayesian model averaging (BMA) method. In task two, we used influence diagrams to study qualitatively how the stakeholders frame the management problem of the herring fishery and elucidate what kind of causalities the different views involve. The paper combines these two tasks to assess the suitability of the methodological choices to participatory modeling in terms of both a modeling tool and participation mode. The paper also assesses the potential of the study to contribute to the development of participatory modeling practices. It is concluded that the subjective perspective to knowledge, that is fundamental in Bayesian theory, suits participatory modeling better than a positivist paradigm that seeks the objective truth. The methodology provides a flexible tool that can be adapted to different kinds of needs and challenges of participatory modeling. The ability of the approach to deal with small data sets makes it cost-effective in participatory contexts. However, the BMA methodology used in modeling the biological uncertainties is so complex that it needs further development before it can be introduced to wider use in participatory contexts.

  13. Involving Stakeholders in Building Integrated Fisheries Models Using Bayesian Methods

    Science.gov (United States)

    Haapasaari, Päivi; Mäntyniemi, Samu; Kuikka, Sakari

    2013-06-01

    A participatory Bayesian approach was used to investigate how the views of stakeholders could be utilized to develop models to help understand the Central Baltic herring fishery. In task one, we applied the Bayesian belief network methodology to elicit the causal assumptions of six stakeholders on factors that influence natural mortality, growth, and egg survival of the herring stock in probabilistic terms. We also integrated the expressed views into a meta-model using the Bayesian model averaging (BMA) method. In task two, we used influence diagrams to study qualitatively how the stakeholders frame the management problem of the herring fishery and elucidate what kind of causalities the different views involve. The paper combines these two tasks to assess the suitability of the methodological choices to participatory modeling in terms of both a modeling tool and participation mode. The paper also assesses the potential of the study to contribute to the development of participatory modeling practices. It is concluded that the subjective perspective to knowledge, that is fundamental in Bayesian theory, suits participatory modeling better than a positivist paradigm that seeks the objective truth. The methodology provides a flexible tool that can be adapted to different kinds of needs and challenges of participatory modeling. The ability of the approach to deal with small data sets makes it cost-effective in participatory contexts. However, the BMA methodology used in modeling the biological uncertainties is so complex that it needs further development before it can be introduced to wider use in participatory contexts.

  14. Modeling supercritical fluid extraction process involving solute-solid interaction

    Energy Technology Data Exchange (ETDEWEB)

    Goto, M.; Roy, B. Kodama, A.; Hirose, T. [Kumamoto Univ., Kumamoto (Japan)

    1998-04-01

    Extraction or leaching of solute from natural solid material is a mass transfer process involving dissolution or release of solutes from a solid matrix. Interaction between the solute and solid matrix often influences the supercritical fluid extraction process. A model accounting for the solute-solid interaction as well as mass transfer is developed. The BET equation is used to incorporate the interaction and the solubility of solutes into the local equilibrium in the model. Experimental data for the supercritical extraction of essential oil and cuticular wax from peppermint leaves are successfully analyzed by the model. The effects of parameters on the extraction behavior are demonstrated to illustrate the concept of the model. 18 refs., 5 figs., 1 tab.

  15. Advances in large-scale crop modeling

    Science.gov (United States)

    Scholze, Marko; Bondeau, Alberte; Ewert, Frank; Kucharik, Chris; Priess, Jörg; Smith, Pascalle

    Intensified human activity and a growing population have changed the climate and the land biosphere. One of the most widely recognized human perturbations is the emission of carbon dioxide (C02) by fossil fuel burning and land-use change. As the terrestrial biosphere is an active player in the global carbon cycle, changes in land use feed back to the climate of the Earth through regulation of the content of atmospheric CO2, the most important greenhouse gas,and changing albedo (e.g., energy partitioning).Recently, the climate modeling community has started to develop more complex Earthsystem models that include marine and terrestrial biogeochemical processes in addition to the representation of atmospheric and oceanic circulation. However, most terrestrial biosphere models simulate only natural, or so-called potential, vegetation and do not account for managed ecosystems such as croplands and pastures, which make up nearly one-third of the Earth's land surface.

  16. Constraining models with a large scalar multiplet

    CERN Document Server

    Earl, Kevin; Logan, Heather E; Pilkington, Terry

    2013-01-01

    Models in which the Higgs sector is extended by a single electroweak scalar multiplet X can possess an accidental global U(1) symmetry at the renormalizable level if X has isospin T greater or equal to 2. We show that all such U(1)-symmetric models are excluded by the interplay of the cosmological relic density of the lightest (neutral) component of X and its direct detection cross section via Z exchange. The sole exception is the T=2 multiplet, whose lightest member decays on a few-day to few-year timescale via a Planck-suppressed dimension-5 operator.

  17. Proposed best practice for projects that involve modelling and simulation.

    Science.gov (United States)

    O'Kelly, Michael; Anisimov, Vladimir; Campbell, Chris; Hamilton, Sinéad

    2017-03-01

    Modelling and simulation has been used in many ways when developing new treatments. To be useful and credible, it is generally agreed that modelling and simulation should be undertaken according to some kind of best practice. A number of authors have suggested elements required for best practice in modelling and simulation. Elements that have been suggested include the pre-specification of goals, assumptions, methods, and outputs. However, a project that involves modelling and simulation could be simple or complex and could be of relatively low or high importance to the project. It has been argued that the level of detail and the strictness of pre-specification should be allowed to vary, depending on the complexity and importance of the project. This best practice document does not prescribe how to develop a statistical model. Rather, it describes the elements required for the specification of a project and requires that the practitioner justify in the specification the omission of any of the elements and, in addition, justify the level of detail provided about each element. This document is an initiative of the Special Interest Group for modelling and simulation. The Special Interest Group for modelling and simulation is a body open to members of Statisticians in the Pharmaceutical Industry and the European Federation of Statisticians in the Pharmaceutical Industry. Examples of a very detailed specification and a less detailed specification are included as appendices. Copyright © 2016 John Wiley & Sons, Ltd.

  18. COST MODEL FOR LARGE URBAN SCHOOLS.

    Science.gov (United States)

    O'BRIEN, RICHARD J.

    THIS DOCUMENT CONTAINS A COST SUBMODEL OF AN URBAN EDUCATIONAL SYSTEM. THIS MODEL REQUIRES THAT PUPIL POPULATION AND PROPOSED SCHOOL BUILDING ARE KNOWN. THE COST ELEMENTS ARE--(1) CONSTRUCTION COSTS OF NEW PLANTS, (2) ACQUISITION AND DEVELOPMENT COSTS OF BUILDING SITES, (3) CURRENT OPERATING EXPENSES OF THE PROPOSED SCHOOL, (4) PUPIL…

  19. Multiobjective adaptive surrogate modeling-based optimization for parameter estimation of large, complex geophysical models

    Science.gov (United States)

    Gong, Wei; Duan, Qingyun; Li, Jianduo; Wang, Chen; Di, Zhenhua; Ye, Aizhong; Miao, Chiyuan; Dai, Yongjiu

    2016-03-01

    Parameter specification is an important source of uncertainty in large, complex geophysical models. These models generally have multiple model outputs that require multiobjective optimization algorithms. Although such algorithms have long been available, they usually require a large number of model runs and are therefore computationally expensive for large, complex dynamic models. In this paper, a multiobjective adaptive surrogate modeling-based optimization (MO-ASMO) algorithm is introduced that aims to reduce computational cost while maintaining optimization effectiveness. Geophysical dynamic models usually have a prior parameterization scheme derived from the physical processes involved, and our goal is to improve all of the objectives by parameter calibration. In this study, we developed a method for directing the search processes toward the region that can improve all of the objectives simultaneously. We tested the MO-ASMO algorithm against NSGA-II and SUMO with 13 test functions and a land surface model - the Common Land Model (CoLM). The results demonstrated the effectiveness and efficiency of MO-ASMO.

  20. Modeling and Control of Large Flexible Structures.

    Science.gov (United States)

    1984-07-31

    systems with hybrid (lumped and distributed) structure. * -3.Development of stabilizing control strategies for nonlinear distributed models, including...process, but much more needs to be done. el .It ;,, "..- ,. ,-,,o’,, .4. : ") Part I: :i: ’i" ’" Wierner-Hopf Methods for Design of Stabilizing ... Control Systems :: Z’" ..-- -~ . . . . .. . . . . . . ... . . . . .......- ~ .. . . S 5 * * .5 .. ** .*% - * 5*55 * . . . . % % ’ * . ’ % , . :.:. -A

  1. Modeling Social Influence in Large Populations

    Science.gov (United States)

    2010-07-13

    feature selection,” The Journal of Machine Learning Research, vol. 3, 2003, pp. 1157– 1182. I. Ajzen , “The theory of planned behavior ,” Organizational...ANSI Std Z39-18 Theory and Introduction 2 Theory : human collectivities are composed of individuals with different meaningful identities, and these...Intrinsically represent a window of time (e.g., before, after, or during a simulation event) Constructed via a theory to model translation of a

  2. Diagnostic imaging of recurred mandibular ameloblastoma with large soft tissue involvement

    Energy Technology Data Exchange (ETDEWEB)

    Park, Kwan Soo; Lee, Sam Sun; Choi, Hang Moon [Dept. of Oral and Maxillofacial Radiology and Dental research Institute, College of Dentistry, Seoul National University, Seoul (Korea, Republic of); Jeon, In Seong [Dept. of Oral and Maxillofacial Surgery, Sanggyepaik Hospital, Seoul (Korea, Republic of)

    2000-12-15

    An uncommon case of a patient with recurrent mandibular ameloblastoma involving various adjacent soft tissues is presented with plain film radiography, computed tomography and magnetic resonance imaging(MRI) and bone scan. The tumor involved mandible and eroded several bones including foramen ovale. This case shows that although an ameloblastoma primarily affect mandible, exact radiographic evaluation of tumor extent will assist the surgeon in the progress of rational approaches to the management of ameloblastoma.

  3. Mathematical modeling of variables involved in dissolution testing.

    Science.gov (United States)

    Gao, Zongming

    2011-11-01

    Dissolution testing is an important technique used for development and quality control of solid oral dosage forms of pharmaceutical products. However, the variability associated with this technique, especially with USP apparatuses 1 and 2, is a concern for both the US Food and Drug Administration and pharmaceutical companies. Dissolution testing involves a number of variables, which can be divided into four main categories: (1) analyst, (2) dissolution apparatus, (3) testing environment, and (4) sample. Both linear and nonlinear models have been used to study dissolution profiles, and various mathematical functions have been used to model the observed data. In this study, several variables, including dissolved gases in the dissolution medium, off-center placement of the test tablet, environmental vibration, and various agitation speeds, were modeled. Mathematical models including Higuchi, Korsmeyer-Peppas, Weibull, and the Noyes-Whitney equation were employed to study the dissolution profile of 10 mg prednisone tablets (NCDA #2) using the USP paddle method. The results showed that the nonlinear models (Korsmeyer-Peppas and Weibull) accurately described the entire dissolution profile. The results also showed that dissolution variables affected dissolution rate constants differently, depending on whether the tablets disintegrated or dissolved.

  4. Cerebrovascular effects of angiotensin converting enzyme inhibition involve large artery dilatation in rats

    DEFF Research Database (Denmark)

    Postiglione, A; Bobkiewicz, T; Vinholdt-Pedersen, E

    1991-01-01

    The aim of the study was to selectively examine the effects of converting enzyme inhibition on the large brain arteries by using concomitant inhibition of carbonic anhydrase to cause severe dilatation of mainly parenchymal resistance vessels....

  5. Flexible modeling frameworks to replace small ensembles of hydrological models and move toward large ensembles?

    Science.gov (United States)

    Addor, Nans; Clark, Martyn P.; Mizukami, Naoki

    2017-04-01

    Climate change impacts on hydrological processes are typically assessed using small ensembles of hydrological models. That is, a handful of hydrological models are typically driven by a larger number of climate models. Such a setup has several limitations. Because the number of hydrological models is small, only a small proportion of the model space is sampled, likely leading to an underestimation of the uncertainties in the projections. Further, sampling is arbitrary: although hydrological models should be selected to provide a representative sample of existing models (in terms of complexity and governing hypotheses), they are instead usually selected based on legacy reasons. Furthermore, running several hydrological models currently constitutes a practical challenge because each model must be setup and calibrated individually. Finally, and probably most importantly, the differences between the projected impacts cannot be directly related to differences between hydrological models, because the models are different in almost every possible aspect. We are hence in a situation in which different hydrological models deliver different projections, but for reasons that are mostly unclear, and in which the uncertainty in the projections is probably underestimated. To overcome these limitations, we are experimenting with the flexible modeling framework FUSE (Framework for Understanding Model Errors). FUSE enables to construct conceptual models piece by piece (in a "pick and mix" approach), so it can be used to generate a large number of models that mimic existing models and/or models that differ from other models in single targeted respect (e.g. how baseflow is generated). FUSE hence allows for controlled modeling experiments, and for a more systematic and exhaustive sampling of the model space. Here we explore climate change impacts over the contiguous USA on a 12km grid using two groups of three models: the first group involves the commonly used models VIC, PRMS and HEC

  6. Does Business Model Affect CSR Involvement? A Survey of Polish Manufacturing and Service Companies

    Directory of Open Access Journals (Sweden)

    Marzanna Katarzyna Witek-Hajduk

    2016-02-01

    Full Text Available The study explores links between types of business models used by companies and their involvement in CSR. As the main part of our conceptual framework we used a business model taxonomy developed by Dudzik and Witek-Hajduk, which identifies five types of models: traditionalists, market players, contractors, distributors, and integrators. From shared characteristics of the business model profiles, we proposed that market players and integrators will show significantly higher levels of involvement in CSR than the three other classes of companies. Among other things, both market players and integrators relied strongly on building own brand value and fostering harmonious supply channel relations, which served as a rationale for our hypothesis. The data for the study were obtained through a combined CATI and CAWI survey on a group of 385 managers of medium and large enterprises. The sample was representative for the three Polish industries of chemical manufacturing, food production, and retailing. Statistical methods included confirmatory factor analysis and one-way ANOVA with contrasts and post hoc tests. The findings supported our hypothesis, showing that market players and integrators were indeed more engaged in CSR than other groups of firms. This may suggest that managers in control of these companies could bolster the integrity of their business models by increasing CSR involvement. Another important contribution of the study was to propose and validate a versatile scale for assessing CSR involvement, which showed measurement invariance for all involved industries.

  7. Influence of Deterministic Attachments for Large Unifying Hybrid Network Model

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Large unifying hybrid network model (LUHPM) introduced the deterministic mixing ratio fd on the basis of the harmonious unification hybrid preferential model, to describe the influence of deterministic attachment to the network topology characteristics,

  8. Long-Term Calculations with Large Air Pollution Models

    DEFF Research Database (Denmark)

    1999-01-01

    Proceedings of the NATO Advanced Research Workshop on Large Scale Computations in Air Pollution Modelling, Sofia, Bulgaria, 6-10 July 1998......Proceedings of the NATO Advanced Research Workshop on Large Scale Computations in Air Pollution Modelling, Sofia, Bulgaria, 6-10 July 1998...

  9. Long-Term Calculations with Large Air Pollution Models

    DEFF Research Database (Denmark)

    1999-01-01

    Proceedings of the NATO Advanced Research Workshop on Large Scale Computations in Air Pollution Modelling, Sofia, Bulgaria, 6-10 July 1998......Proceedings of the NATO Advanced Research Workshop on Large Scale Computations in Air Pollution Modelling, Sofia, Bulgaria, 6-10 July 1998...

  10. Using Quality Circles to Enhance Student Involvement and Course Quality in a Large Undergraduate Food Science and Human Nutrition Course

    Science.gov (United States)

    Schmidt, S. J.; Parmer, M. S.; Bohn, D. M.

    2005-01-01

    Large undergraduate classes are a challenge to manage, to engage, and to assess, yet such formidable classes can flourish when student participation is facilitated. One method of generating authentic student involvement is implementation of quality circles by means of a Student Feedback Committee (SFC), which is a volunteer problem-solving and…

  11. Using Quality Circles to Enhance Student Involvement and Course Quality in a Large Undergraduate Food Science and Human Nutrition Course

    Science.gov (United States)

    Schmidt, S. J.; Parmer, M. S.; Bohn, D. M.

    2005-01-01

    Large undergraduate classes are a challenge to manage, to engage, and to assess, yet such formidable classes can flourish when student participation is facilitated. One method of generating authentic student involvement is implementation of quality circles by means of a Student Feedback Committee (SFC), which is a volunteer problem-solving and…

  12. Using Agent Base Models to Optimize Large Scale Network for Large System Inventories

    Science.gov (United States)

    Shameldin, Ramez Ahmed; Bowling, Shannon R.

    2010-01-01

    The aim of this paper is to use Agent Base Models (ABM) to optimize large scale network handling capabilities for large system inventories and to implement strategies for the purpose of reducing capital expenses. The models used in this paper either use computational algorithms or procedure implementations developed by Matlab to simulate agent based models in a principal programming language and mathematical theory using clusters, these clusters work as a high performance computational performance to run the program in parallel computational. In both cases, a model is defined as compilation of a set of structures and processes assumed to underlie the behavior of a network system.

  13. Modeling Large sound sources in a room acoustical calculation program

    DEFF Research Database (Denmark)

    Christensen, Claus Lynge

    1999-01-01

    A room acoustical model capable of modelling point, line and surface sources is presented. Line and surface sources are modelled using a special ray-tracing algorithm detecting the radiation pattern of the surfaces in the room. Point sources are modelled using a hybrid calculation method combining...... this ray-tracing method with Image source modelling. With these three source types, it is possible to model large and complex sound sources in workrooms....

  14. Modeling Large sound sources in a room acoustical calculation program

    DEFF Research Database (Denmark)

    Christensen, Claus Lynge

    1999-01-01

    A room acoustical model capable of modelling point, line and surface sources is presented. Line and surface sources are modelled using a special ray-tracing algorithm detecting the radiation pattern of the surfaces in the room. Point sources are modelled using a hybrid calculation method combining...... this ray-tracing method with Image source modelling. With these three source types, it is possible to model large and complex sound sources in workrooms....

  15. Spectroscopic evidence of large aspherical β-NAT particles involved in denitrification in the December 2011 Arctic stratosphere

    Science.gov (United States)

    Woiwode, Wolfgang; Höpfner, Michael; Bi, Lei; Pitts, Michael C.; Poole, Lamont R.; Oelhaf, Hermann; Molleker, Sergej; Borrmann, Stephan; Klingebiel, Marcus; Belyaev, Gennady; Ebersoldt, Andreas; Griessbach, Sabine; Grooß, Jens-Uwe; Gulde, Thomas; Krämer, Martina; Maucher, Guido; Piesch, Christof; Rolf, Christian; Sartorius, Christian; Spang, Reinhold; Orphal, Johannes

    2016-07-01

    We analyze polar stratospheric cloud (PSC) signatures in airborne MIPAS-STR (Michelson Interferometer for Passive Atmospheric Sounding - STRatospheric aircraft) observations in the spectral regions from 725 to 990 and 1150 to 1350 cm-1 under conditions suitable for the existence of nitric acid trihydrate (NAT) above northern Scandinavia on 11 December 2011. The high-resolution infrared limb emission spectra of MIPAS-STR show a characteristic "shoulder-like" signature in the spectral region around 820 cm-1, which is attributed to the ν2 symmetric deformation mode of NO3- in β-NAT. Using radiative transfer calculations involving Mie and T-Matrix methods, the spectral signatures of spherical and aspherical particles are simulated. The simulations are constrained using collocated in situ particle measurements. Simulations assuming highly aspherical spheroids with aspect ratios (AR) of 0.1 or 10.0 and a lognormal particle mode with a mode radius of 4.8 µm reproduce the observed spectra to a high degree. A smaller lognormal mode with a mode radius of 2.0 µm, which is also taken into account, plays only a minor role. Within the scenarios analyzed, the best overall agreement is found for elongated spheroids with AR = 0.1. Simulations of spherical particles and spheroids with AR = 0.5 and 2.0 return results very similar to each other and do not allow us to reproduce the signature around 820 cm-1. The observed "shoulder-like" signature is explained by the combination of the absorption/emission and scattering characteristics of large highly aspherical β-NAT particles. The size distribution supported by our results corresponds to ˜ 9 ppbv of gas-phase equivalent HNO3 at the flight altitude of ˜ 18.5 km. The results are compared with the size distributions derived from the in situ observations, a corresponding Chemical Lagrangian Model of the Stratosphere (CLaMS) simulation, and excess gas-phase HNO3 observed in a nitrification layer directly below the observed PSC. The

  16. Multistability in Large Scale Models of Brain Activity.

    Directory of Open Access Journals (Sweden)

    Mathieu Golos

    2015-12-01

    Full Text Available Noise driven exploration of a brain network's dynamic repertoire has been hypothesized to be causally involved in cognitive function, aging and neurodegeneration. The dynamic repertoire crucially depends on the network's capacity to store patterns, as well as their stability. Here we systematically explore the capacity of networks derived from human connectomes to store attractor states, as well as various network mechanisms to control the brain's dynamic repertoire. Using a deterministic graded response Hopfield model with connectome-based interactions, we reconstruct the system's attractor space through a uniform sampling of the initial conditions. Large fixed-point attractor sets are obtained in the low temperature condition, with a bigger number of attractors than ever reported so far. Different variants of the initial model, including (i a uniform activation threshold or (ii a global negative feedback, produce a similarly robust multistability in a limited parameter range. A numerical analysis of the distribution of the attractors identifies spatially-segregated components, with a centro-medial core and several well-delineated regional patches. Those different modes share similarity with the fMRI independent components observed in the "resting state" condition. We demonstrate non-stationary behavior in noise-driven generalizations of the models, with different meta-stable attractors visited along the same time course. Only the model with a global dynamic density control is found to display robust and long-lasting non-stationarity with no tendency toward either overactivity or extinction. The best fit with empirical signals is observed at the edge of multistability, a parameter region that also corresponds to the highest entropy of the attractors.

  17. Comparison Between Overtopping Discharge in Small and Large Scale Models

    DEFF Research Database (Denmark)

    Helgason, Einar; Burcharth, Hans F.

    2006-01-01

    small and large scale model tests show no clear evidence of scale effects for overtopping above a threshold value. In the large scale model no overtopping was measured for waveheights below Hs = 0.5m as the water sunk into the voids between the stones on the crest. For low overtopping scale effects...... are presented as the small-scale model underpredicts the overtopping discharge....

  18. The large GTPase Mx1 is involved in apical transport in MDCK cells.

    Science.gov (United States)

    Hoff, Florian; Greb, Christoph; Hollmann, Christina; Hönig, Ellena; Jacob, Ralf

    2014-09-01

    In epithelial cells apical proteins are transported by specific transport carriers to the correct membrane domain. The composition of these carriers is heterogeneous and comprises components such as motor proteins, annexins, lectins, Rab GTPases and cargo molecules. Here, we provide biochemical and fluorescence microscopic data to show that the dynamin-related large GTPase Mx1 is a component of post-Golgi vesicles carrying the neurotrophin receptor p75(NTR) . Moreover, siRNA-mediated depletion of Mx1 significantly decreased the transport efficiency of apical proteins in MDCK cells. In conclusion, Mx1 plays a crucial role in the delivery of cargo molecules to the apical membrane of epithelial cells.

  19. Heart of Lymphoma: Primary Mediastinal Large B-Cell Lymphoma with Endomyocardial Involvement

    Directory of Open Access Journals (Sweden)

    Elisa Rogowitz

    2013-01-01

    Full Text Available Primary mediastinal B-cell lymphoma (PMBCL is an uncommon aggressive subset of diffuse large B-cell lymphomas. Although PMBCL frequently spreads locally from the thymus into the pleura or pericardium, it rarely invades directly through the heart. Herein, we report a case of a young Mexican female diagnosed with PMBCL with clear infiltration of lymphoma through the cardiac wall and into the right atrium and tricuspid valve leading to tricuspid regurgitation. This was demonstrated by cardiac MRI and transthoracic echocardiogram. In addition, cardiac MRI and CT scan of the chest revealed the large mediastinal mass completely surrounding and eroding into the superior vena cava (SVC wall causing a collar of stokes. The cardiac and SVC infiltration created a significant therapeutic challenge as lymphomas are very responsive to chemotherapy, and treatment could potentially lead to vascular wall rupture and hemorrhage. Despite the lack of conclusive data on chemotherapy-induced hemodynamic compromise in such scenarios, her progressive severe SVC syndrome and respiratory distress necessitated urgent intervention. In addition to the unique presentation of this rare lymphoma, our case report highlights the safety of R-CHOP treatment.

  20. Modelling Large sound sources in a room acoustical calculation program

    DEFF Research Database (Denmark)

    Christensen, Claus Lynge

    1999-01-01

    A room acoustical model capable of modelling point, line and surface sources is presented. Line and surfacesources are modelled using a special ray-tracing algorithm detecting the radiation pattern of the surfaces in the room.Point sources are modelled using a hybrid calculation method combining...... this ray-tracing method with Image sourcemodelling. With these three source types, it is possible to model large and complex sound sources in workrooms....

  1. Modelling Large sound sources in a room acoustical calculation program

    DEFF Research Database (Denmark)

    Christensen, Claus Lynge

    1999-01-01

    A room acoustical model capable of modelling point, line and surface sources is presented. Line and surfacesources are modelled using a special ray-tracing algorithm detecting the radiation pattern of the surfaces in the room.Point sources are modelled using a hybrid calculation method combining...... this ray-tracing method with Image sourcemodelling. With these three source types, it is possible to model large and complex sound sources in workrooms....

  2. Definition Study for Space Shuttle Experiments Involving Large, Steerable Millimeter-Wave Antenna Arrays

    Science.gov (United States)

    Levis, C. A.

    1976-01-01

    The potential uses and techniques for the shuttle spacelab Millimeter Wave Large Aperture Antenna Experiment (MWLAE) are documented. Potential uses are identified: applications to radio astronomy, the sensing of atmospheric turbulence by its effect on water vapor line emissions, and the monitoring of oil spills by multifrequency radiometry. IF combining is preferable to RF combining with respect to signal to noise ratio for communications receiving antennas of the size proposed for MWLAE. A design approach using arrays of subapertures is proposed to reduce the number of phase shifters and mixers for uses which require a filled aperture. Correlation radiometry and a scheme utilizing synchronous Dicke switches and IF combining are proposed as potential solutions.

  3. A deployable in vivo EPR tooth dosimeter for triage after a radiation event involving large populations

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Benjamin B., E-mail: Benjamin.B.Williams@dartmouth.edu [Dartmouth Physically Based Biodosimetry Center for Medical Countermeasures Against Radiation (Dart-Dose CMCR), Dartmouth Medical School, Hanover, NH 03768 (United States); Section of Radiation Oncology, Department of Medicine, Dartmouth Hitchcock Medical Center, Lebanon, NH (United States); Dong, Ruhong [Dartmouth Physically Based Biodosimetry Center for Medical Countermeasures Against Radiation (Dart-Dose CMCR), Dartmouth Medical School, Hanover, NH 03768 (United States); Flood, Ann Barry [Dartmouth Physically Based Biodosimetry Center for Medical Countermeasures Against Radiation (Dart-Dose CMCR), Dartmouth Medical School, Hanover, NH 03768 (United States); Clin-EPR, LLC, Lyme, NH (United States); Grinberg, Oleg [Clin-EPR, LLC, Lyme, NH (United States); Kmiec, Maciej; Lesniewski, Piotr N.; Matthews, Thomas P.; Nicolalde, Roberto J.; Raynolds, Tim [Dartmouth Physically Based Biodosimetry Center for Medical Countermeasures Against Radiation (Dart-Dose CMCR), Dartmouth Medical School, Hanover, NH 03768 (United States); Salikhov, Ildar K. [Clin-EPR, LLC, Lyme, NH (United States); Swartz, Harold M. [Dartmouth Physically Based Biodosimetry Center for Medical Countermeasures Against Radiation (Dart-Dose CMCR), Dartmouth Medical School, Hanover, NH 03768 (United States); Clin-EPR, LLC, Lyme, NH (United States)

    2011-09-15

    In order to meet the potential need for emergency large-scale retrospective radiation biodosimetry following an accident or attack, we have developed instrumentation and methodology for in vivo electron paramagnetic resonance spectroscopy to quantify concentrations of radiation-induced radicals within intact teeth. This technique has several very desirable characteristics for triage, including independence from confounding biologic factors, a non-invasive measurement procedure, the capability to make measurements at any time after the event, suitability for use by non-expert operators at the site of an event, and the ability to provide immediate estimates of individual doses. Throughout development there has been a particular focus on the need for a deployable system, including instrumental requirements for transport and field use, the need for high throughput, and use by minimally trained operators. Numerous measurements have been performed using this system in clinical and other non-laboratory settings, including in vivo measurements with unexposed populations as well as patients undergoing radiation therapies. The collection and analyses of sets of three serially-acquired spectra with independent placements of the resonator, in a data collection process lasting approximately 5 min, provides dose estimates with standard errors of prediction of approximately 1 Gy. As an example, measurements were performed on incisor teeth of subjects who had either received no irradiation or 2 Gy total body irradiation for prior bone marrow transplantation; this exercise provided a direct and challenging test of our capability to identify subjects who would be in need of acute medical care. -- Highlights: > Advances in radiation biodosimetry are needed for large-scale emergency response. > Radiation-induced radicals in tooth enamel can be measured using in vivo EPR. > A novel transportable spectrometer was applied in the laboratory and at remote sites. > The current instrument

  4. Large scale stochastic spatio-temporal modelling with PCRaster

    Science.gov (United States)

    Karssenberg, Derek; Drost, Niels; Schmitz, Oliver; de Jong, Kor; Bierkens, Marc F. P.

    2013-04-01

    PCRaster is a software framework for building spatio-temporal models of land surface processes (http://www.pcraster.eu). Building blocks of models are spatial operations on raster maps, including a large suite of operations for water and sediment routing. These operations are available to model builders as Python functions. The software comes with Python framework classes providing control flow for spatio-temporal modelling, Monte Carlo simulation, and data assimilation (Ensemble Kalman Filter and Particle Filter). Models are built by combining the spatial operations in these framework classes. This approach enables modellers without specialist programming experience to construct large, rather complicated models, as many technical details of modelling (e.g., data storage, solving spatial operations, data assimilation algorithms) are taken care of by the PCRaster toolbox. Exploratory modelling is supported by routines for prompt, interactive visualisation of stochastic spatio-temporal data generated by the models. The high computational requirements for stochastic spatio-temporal modelling, and an increasing demand to run models over large areas at high resolution, e.g. in global hydrological modelling, require an optimal use of available, heterogeneous computing resources by the modelling framework. Current work in the context of the eWaterCycle project is on a parallel implementation of the modelling engine, capable of running on a high-performance computing infrastructure such as clusters and supercomputers. Model runs will be distributed over multiple compute nodes and multiple processors (GPUs and CPUs). Parallelization will be done by parallel execution of Monte Carlo realizations and sub regions of the modelling domain. In our approach we use multiple levels of parallelism, improving scalability considerably. On the node level we will use OpenCL, the industry standard for low-level high performance computing kernels. To combine multiple nodes we will use

  5. Large scale stochastic spatio-temporal modelling with PCRaster

    NARCIS (Netherlands)

    Karssenberg, D.J.; Drost, N.; Schmitz, O.; Jong, K. de; Bierkens, M.F.P.

    2013-01-01

    PCRaster is a software framework for building spatio-temporal models of land surface processes (http://www.pcraster.eu). Building blocks of models are spatial operations on raster maps, including a large suite of operations for water and sediment routing. These operations are available to model

  6. Large scale stochastic spatio-temporal modelling with PCRaster

    NARCIS (Netherlands)

    Karssenberg, D.J.; Drost, N.; Schmitz, O.; Jong, K. de; Bierkens, M.F.P.

    2013-01-01

    PCRaster is a software framework for building spatio-temporal models of land surface processes (http://www.pcraster.eu). Building blocks of models are spatial operations on raster maps, including a large suite of operations for water and sediment routing. These operations are available to model buil

  7. An accurate and simple large signal model of HEMT

    DEFF Research Database (Denmark)

    Liu, Qing

    1989-01-01

    A large-signal model of discrete HEMTs (high-electron-mobility transistors) has been developed. It is simple and suitable for SPICE simulation of hybrid digital ICs. The model parameters are extracted by using computer programs and data provided by the manufacturer. Based on this model, a hybrid...

  8. Aero-acoustic modeling using large eddy simulation

    DEFF Research Database (Denmark)

    Shen, Wen Zhong; Sørensen, Jens Nørkær

    2007-01-01

    The splitting technique for aero-acoustic computations is extended to simulate three-dimensional flow and acoustic waves from airfoils. The aero-acoustic model is coupled to a sub-grid-scale turbulence model for Large-Eddy Simulations. In the first test case, the model is applied to compute laminar...

  9. Multivariate Statistical Analysis Software Technologies for Astrophysical Research Involving Large Data Bases

    Science.gov (United States)

    Djorgovski, S. G.

    1994-01-01

    We developed a package to process and analyze the data from the digital version of the Second Palomar Sky Survey. This system, called SKICAT, incorporates the latest in machine learning and expert systems software technology, in order to classify the detected objects objectively and uniformly, and facilitate handling of the enormous data sets from digital sky surveys and other sources. The system provides a powerful, integrated environment for the manipulation and scientific investigation of catalogs from virtually any source. It serves three principal functions: image catalog construction, catalog management, and catalog analysis. Through use of the GID3* Decision Tree artificial induction software, SKICAT automates the process of classifying objects within CCD and digitized plate images. To exploit these catalogs, the system also provides tools to merge them into a large, complex database which may be easily queried and modified when new data or better methods of calibrating or classifying become available. The most innovative feature of SKICAT is the facility it provides to experiment with and apply the latest in machine learning technology to the tasks of catalog construction and analysis. SKICAT provides a unique environment for implementing these tools for any number of future scientific purposes. Initial scientific verification and performance tests have been made using galaxy counts and measurements of galaxy clustering from small subsets of the survey data, and a search for very high redshift quasars. All of the tests were successful and produced new and interesting scientific results. Attachments to this report give detailed accounts of the technical aspects of the SKICAT system, and of some of the scientific results achieved to date. We also developed a user-friendly package for multivariate statistical analysis of small and moderate-size data sets, called STATPROG. The package was tested extensively on a number of real scientific applications and has

  10. Multivariate statistical analysis software technologies for astrophysical research involving large data bases

    Science.gov (United States)

    Djorgovski, S. George

    1994-01-01

    We developed a package to process and analyze the data from the digital version of the Second Palomar Sky Survey. This system, called SKICAT, incorporates the latest in machine learning and expert systems software technology, in order to classify the detected objects objectively and uniformly, and facilitate handling of the enormous data sets from digital sky surveys and other sources. The system provides a powerful, integrated environment for the manipulation and scientific investigation of catalogs from virtually any source. It serves three principal functions: image catalog construction, catalog management, and catalog analysis. Through use of the GID3* Decision Tree artificial induction software, SKICAT automates the process of classifying objects within CCD and digitized plate images. To exploit these catalogs, the system also provides tools to merge them into a large, complete database which may be easily queried and modified when new data or better methods of calibrating or classifying become available. The most innovative feature of SKICAT is the facility it provides to experiment with and apply the latest in machine learning technology to the tasks of catalog construction and analysis. SKICAT provides a unique environment for implementing these tools for any number of future scientific purposes. Initial scientific verification and performance tests have been made using galaxy counts and measurements of galaxy clustering from small subsets of the survey data, and a search for very high redshift quasars. All of the tests were successful, and produced new and interesting scientific results. Attachments to this report give detailed accounts of the technical aspects for multivariate statistical analysis of small and moderate-size data sets, called STATPROG. The package was tested extensively on a number of real scientific applications, and has produced real, published results.

  11. Risk factors and patterns of lymph node involvement in primary gastric large B-cell lymphoma: implications for target definition

    Directory of Open Access Journals (Sweden)

    Zhang X

    2016-07-01

    Full Text Available Ximei Zhang, Peiguo Wang, Lujun Zhao, Zhiyong Yuan, Ping Wang Department of Radiation Oncology, Tianjin’s Clinical Research Center for Cancer and Key Laboratory of Cancer Prevention and Therapy, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, People’s Republic of China Background: The aim of this study was to identify the appropriate radiation volume for primary gastric diffuse large B-cell lymphoma (PG-DLBCL.Methods: We retrospectively analyzed the clinical and pathological findings of 68 patients treated with total gastrectomy and D2 lymphadenectomy.Results: There were 23, 14, and 29 patients with stage I, stage II, and stage IIE disease, respectively, and 30 patients had lymph node involvement. Primary tumor location, as well as the depth of invasion, was significantly associated with lymph node involvement. When the tumor was limited to the muscularis, the involved lymph nodes were found to be perigastric nodes. For tumors invading beyond the muscularis, regional lymph nodes were involved.Conclusion: The optimal radiation volume for patients with PG-DLBCL is largely dependent on the primary location and depth of invasion. Larger series and longer follow-up are needed to further delineate the radiation volumes for PG-DLBCL. Keywords: primary gastric lymphoma, failure patterns, radiotherapy, chemotherapy, prognosis

  12. Large field inflation models from higher-dimensional gauge theories

    Science.gov (United States)

    Furuuchi, Kazuyuki; Koyama, Yoji

    2015-02-01

    Motivated by the recent detection of B-mode polarization of CMB by BICEP2 which is possibly of primordial origin, we study large field inflation models which can be obtained from higher-dimensional gauge theories. The constraints from CMB observations on the gauge theory parameters are given, and their naturalness are discussed. Among the models analyzed, Dante's Inferno model turns out to be the most preferred model in this framework.

  13. Large field inflation models from higher-dimensional gauge theories

    Energy Technology Data Exchange (ETDEWEB)

    Furuuchi, Kazuyuki [Manipal Centre for Natural Sciences, Manipal University, Manipal, Karnataka 576104 (India); Koyama, Yoji [Department of Physics, National Tsing-Hua University, Hsinchu 30013, Taiwan R.O.C. (China)

    2015-02-23

    Motivated by the recent detection of B-mode polarization of CMB by BICEP2 which is possibly of primordial origin, we study large field inflation models which can be obtained from higher-dimensional gauge theories. The constraints from CMB observations on the gauge theory parameters are given, and their naturalness are discussed. Among the models analyzed, Dante’s Inferno model turns out to be the most preferred model in this framework.

  14. A model of the supplier involvement in the product innovation

    Directory of Open Access Journals (Sweden)

    Kumar Manoj

    2017-01-01

    Full Text Available In this paper we examine the product innovation in a supply chain by a supplier and derive a model for a supplier’s product innovation policy. The product innovation of a supplier can contribute to the long-term competitiveness for the supply chain, and as it is for many supply chains a major factor, it should be considered in the development of strategies for a supplier. Here, we evaluate the effectiveness of supplier product innovation as a strategic tool to enhance the competitiveness and viability of supply chain. This paper explores the dynamic research performance of a supplier with endogenous time preference under a given arrangement of product innovation. We find that the optimal effort level and the achieved product innovation obey a saddle point path, or show tremendous fluctuations even without introducing the stochastic nature of product innovative activity. We also find that the fluctuation frequency is largely dependent both on the supplier’s characteristics such as supplier’s product innovative ability and on the nature of product innovation process per se. Short-run analyses are also made on the effect of supply chain cooperation in the product innovation process.

  15. Large N Scalars: From Glueballs to Dynamical Higgs Models

    CERN Document Server

    Sannino, Francesco

    2015-01-01

    We construct effective Lagrangians, and corresponding counting schemes, valid to describe the dynamics of the lowest lying large N stable massive composite state emerging in strongly coupled theories. The large N counting rules can now be employed when computing quantum corrections via an effective Lagrangian description. The framework allows for systematic investigations of composite dynamics of non-Goldstone nature. Relevant examples are the lightest glueball states emerging in any Yang-Mills theory. We further apply the effective approach and associated counting scheme to composite models at the electroweak scale. To illustrate the formalism we consider the possibility that the Higgs emerges as: the lightest glueball of a new composite theory; the large N scalar meson in models of dynamical electroweak symmetry breaking; the large N pseudodilaton useful also for models of near-conformal dynamics. For each of these realisations we determine the leading N corrections to the electroweak precision parameters. ...

  16. Modelling and measurements of wakes in large wind farms

    DEFF Research Database (Denmark)

    Barthelmie, Rebecca Jane; Rathmann, Ole; Frandsen, Sten Tronæs;

    2007-01-01

    The paper presents research conducted in the Flow workpackage of the EU funded UPWIND project which focuses on improving models of flow within and downwind of large wind farms in complex terrain and offshore. The main activity is modelling the behaviour of wind turbine wakes in order to improve...

  17. Modelling and measurements of wakes in large wind farms

    DEFF Research Database (Denmark)

    Barthelmie, Rebecca Jane; Rathmann, Ole; Frandsen, Sten Tronæs

    2007-01-01

    The paper presents research conducted in the Flow workpackage of the EU funded UPWIND project which focuses on improving models of flow within and downwind of large wind farms in complex terrain and offshore. The main activity is modelling the behaviour of wind turbine wakes in order to improve p...

  18. Effectiveness of Peer Education Involving the use of Theoretical Models

    OpenAIRE

    2008-01-01

    The effectiveness of health education among university students who received peer-support training was investigated using four theoretical models : the health belief model, the self-efficacy model, social support and the transtheoretical model of health behavior change. Results suggested that the four theoretical models were useful in evaluating the effect of peer education as an alternative assessment tool. In light of this, it is suggested that the use of the theoretical models may facilita...

  19. Large scale experiments as a tool for numerical model development

    DEFF Research Database (Denmark)

    Kirkegaard, Jens; Hansen, Erik Asp; Fuchs, Jesper;

    2003-01-01

    for improvement of the reliability of physical model results. This paper demonstrates by examples that numerical modelling benefits in various ways from experimental studies (in large and small laboratory facilities). The examples range from very general hydrodynamic descriptions of wave phenomena to specific......Experimental modelling is an important tool for study of hydrodynamic phenomena. The applicability of experiments can be expanded by the use of numerical models and experiments are important for documentation of the validity of numerical tools. In other cases numerical tools can be applied...... hydrodynamic interaction with structures. The examples also show that numerical model development benefits from international co-operation and sharing of high quality results....

  20. Toy Model for Large Non-Symmetric Random Matrices

    CERN Document Server

    Snarska, Małgorzata

    2010-01-01

    Non-symmetric rectangular correlation matrices occur in many problems in economics. We test the method of extracting statistically meaningful correlations between input and output variables of large dimensionality and build a toy model for artificially included correlations in large random time series.The results are then applied to analysis of polish macroeconomic data and can be used as an alternative to classical cointegration approach.

  1. Synchronous, primary, diffuse, large B-cell lymphomas involving the ethmoid sinus and epiglottis: a rare clinical entity.

    Science.gov (United States)

    Yoon, Young-Ho; Park, Won-Young; Choi, Young-Jin; Cho, Kyu-Sup

    2013-03-01

    Non-Hodgkin's lymphoma (NHL) affecting the ethmoid sinus and epiglottis is uncommon. Furthermore, synchronous NHLs involving the ethmoid sinus and epiglottis are extremely rare and have not been reported previously. This article reports synchronous, primary, diffuse, large B-cell lymphoma (DLBCL) arising in the ethmoid sinus and epiglottis, which was successfully treated by immunochemotherapy. A careful examination of the head and neck is necessary to determine the existence of multiple synchronous primary tumors, because primary synchronous occurrence of DLBCL in the head and neck is unusual and can impact the prognosis adversely.

  2. Statistical Modeling of Large-Scale Scientific Simulation Data

    Energy Technology Data Exchange (ETDEWEB)

    Eliassi-Rad, T; Baldwin, C; Abdulla, G; Critchlow, T

    2003-11-15

    With the advent of massively parallel computer systems, scientists are now able to simulate complex phenomena (e.g., explosions of a stars). Such scientific simulations typically generate large-scale data sets over the spatio-temporal space. Unfortunately, the sheer sizes of the generated data sets make efficient exploration of them impossible. Constructing queriable statistical models is an essential step in helping scientists glean new insight from their computer simulations. We define queriable statistical models to be descriptive statistics that (1) summarize and describe the data within a user-defined modeling error, and (2) are able to answer complex range-based queries over the spatiotemporal dimensions. In this chapter, we describe systems that build queriable statistical models for large-scale scientific simulation data sets. In particular, we present our Ad-hoc Queries for Simulation (AQSim) infrastructure, which reduces the data storage requirements and query access times by (1) creating and storing queriable statistical models of the data at multiple resolutions, and (2) evaluating queries on these models of the data instead of the entire data set. Within AQSim, we focus on three simple but effective statistical modeling techniques. AQSim's first modeling technique (called univariate mean modeler) computes the ''true'' (unbiased) mean of systematic partitions of the data. AQSim's second statistical modeling technique (called univariate goodness-of-fit modeler) uses the Andersen-Darling goodness-of-fit method on systematic partitions of the data. Finally, AQSim's third statistical modeling technique (called multivariate clusterer) utilizes the cosine similarity measure to cluster the data into similar groups. Our experimental evaluations on several scientific simulation data sets illustrate the value of using these statistical models on large-scale simulation data sets.

  3. Satellite image collection modeling for large area hazard emergency response

    Science.gov (United States)

    Liu, Shufan; Hodgson, Michael E.

    2016-08-01

    Timely collection of critical hazard information is the key to intelligent and effective hazard emergency response decisions. Satellite remote sensing imagery provides an effective way to collect critical information. Natural hazards, however, often have large impact areas - larger than a single satellite scene. Additionally, the hazard impact area may be discontinuous, particularly in flooding or tornado hazard events. In this paper, a spatial optimization model is proposed to solve the large area satellite image acquisition planning problem in the context of hazard emergency response. In the model, a large hazard impact area is represented as multiple polygons and image collection priorities for different portion of impact area are addressed. The optimization problem is solved with an exact algorithm. Application results demonstrate that the proposed method can address the satellite image acquisition planning problem. A spatial decision support system supporting the optimization model was developed. Several examples of image acquisition problems are used to demonstrate the complexity of the problem and derive optimized solutions.

  4. Modelling and transient stability of large wind farms

    DEFF Research Database (Denmark)

    Akhmatov, Vladislav; Knudsen, Hans; Nielsen, Arne Hejde

    2003-01-01

    The paper is dealing-with modelling and short-term Voltage stability considerations of large wind farms. A physical model of a large offshore wind farm consisting of a large number of windmills is implemented in the dynamic simulation tool PSS/E. Each windmill in the wind farm is represented...... by a physical model of grid-connected windmills. The windmill generators ate conventional induction generators and the wind farm is ac-connected to the power system. Improvements-of short-term voltage stability in case of failure events in the external power system are treated with use of conventional generator...... of dynamic reactive compensation demands. In case of blade angle control applied at failure events, dynamic reactive compensation is not necessary for maintaining the voltage stability....

  5. Dualities in 3D large N vector models

    Science.gov (United States)

    Muteeb, Nouman; Zayas, Leopoldo A. Pando; Quevedo, Fernando

    2016-05-01

    Using an explicit path integral approach we derive non-abelian bosonization and duality of 3D systems in the large N limit. We first consider a fermionic U( N) vector model coupled to level k Chern-Simons theory, following standard techniques we gauge the original global symmetry and impose the corresponding field strength F μν to vanish introducing a Lagrange multiplier Λ. Exchanging the order of integrations we obtain the bosonized theory with Λ as the propagating field using the large N rather than the previously used large mass limit. Next we follow the same procedure to dualize the scalar U ( N) vector model coupled to Chern-Simons and find its corresponding dual theory. Finally, we compare the partition functions of the two resulting theories and find that they agree in the large N limit including a level/rank duality. This provides a constructive evidence for previous proposals on level/rank duality of 3D vector models in the large N limit. We also present a partial analysis at subleading order in large N and find that the duality does not generically hold at this level.

  6. Dualities in 3D large N vector models

    Energy Technology Data Exchange (ETDEWEB)

    Muteeb, Nouman [The Abdus Salam International Centre for Theoretical Physics, ICTP,Strada Costiera 11, 34014 Trieste (Italy); SISSA,Via Bonomea 265, 34136 Trieste (Italy); Zayas, Leopoldo A. Pando [The Abdus Salam International Centre for Theoretical Physics, ICTP,Strada Costiera 11, 34014 Trieste (Italy); Michigan Center for Theoretical Physics, Department of Physics,University of Michigan, Ann Arbor, MI 48109 (United States); Quevedo, Fernando [The Abdus Salam International Centre for Theoretical Physics, ICTP,Strada Costiera 11, 34014 Trieste (Italy); DAMTP, CMS, University of Cambridge,Wilberforce Road, Cambridge, CB3 0WA (United Kingdom)

    2016-05-09

    Using an explicit path integral approach we derive non-abelian bosonization and duality of 3D systems in the large N limit. We first consider a fermionic U(N) vector model coupled to level k Chern-Simons theory, following standard techniques we gauge the original global symmetry and impose the corresponding field strength F{sub μν} to vanish introducing a Lagrange multiplier Λ. Exchanging the order of integrations we obtain the bosonized theory with Λ as the propagating field using the large N rather than the previously used large mass limit. Next we follow the same procedure to dualize the scalar U(N) vector model coupled to Chern-Simons and find its corresponding dual theory. Finally, we compare the partition functions of the two resulting theories and find that they agree in the large N limit including a level/rank duality. This provides a constructive evidence for previous proposals on level/rank duality of 3D vector models in the large N limit. We also present a partial analysis at subleading order in large N and find that the duality does not generically hold at this level.

  7. Lithium-ion batteries modeling involving fractional differentiation

    Science.gov (United States)

    Sabatier, Jocelyn; Merveillaut, Mathieu; Francisco, Junior Mbala; Guillemard, Franck; Porcelatto, Denis

    2014-09-01

    With hybrid and electric vehicles development, automobile battery monitoring systems (BMS) have to meet the new requirements. These systems have to give information on state of health, state of charge, available power. To get this information, BMS often implement battery models. Accuracy of the information manipulated by the BMS thus depends on the model accuracy. This paper is within this framework and addresses lithium-ion battery modeling. The proposed fractional model is based on simplifications of an electrochemical model and on resolution of some partial differential equations used in its description. Such an approach permits to get a simple model in which electrochemical variables and parameters still appear.

  8. Exposing earth surface process model simulations to a large audience

    Science.gov (United States)

    Overeem, I.; Kettner, A. J.; Borkowski, L.; Russell, E. L.; Peddicord, H.

    2015-12-01

    The Community Surface Dynamics Modeling System (CSDMS) represents a diverse group of >1300 scientists who develop and apply numerical models to better understand the Earth's surface. CSDMS has a mandate to make the public more aware of model capabilities and therefore started sharing state-of-the-art surface process modeling results with large audiences. One platform to reach audiences outside the science community is through museum displays on 'Science on a Sphere' (SOS). Developed by NOAA, SOS is a giant globe, linked with computers and multiple projectors and can display data and animations on a sphere. CSDMS has developed and contributed model simulation datasets for the SOS system since 2014, including hydrological processes, coastal processes, and human interactions with the environment. Model simulations of a hydrological and sediment transport model (WBM-SED) illustrate global river discharge patterns. WAVEWATCH III simulations have been specifically processed to show the impacts of hurricanes on ocean waves, with focus on hurricane Katrina and super storm Sandy. A large world dataset of dams built over the last two centuries gives an impression of the profound influence of humans on water management. Given the exposure of SOS, CSDMS aims to contribute at least 2 model datasets a year, and will soon provide displays of global river sediment fluxes and changes of the sea ice free season along the Arctic coast. Over 100 facilities worldwide show these numerical model displays to an estimated 33 million people every year. Datasets storyboards, and teacher follow-up materials associated with the simulations, are developed to address common core science K-12 standards. CSDMS dataset documentation aims to make people aware of the fact that they look at numerical model results, that underlying models have inherent assumptions and simplifications, and that limitations are known. CSDMS contributions aim to familiarize large audiences with the use of numerical

  9. Modeling Study of Planar Flexible Manipulator Undergoing Large Deformation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The planar flexible manipulator undergoing large deformation is investigated by using finite element method (FEM). Three kinds of reference frames are employed to describe the deformation of arbitrary point in the flexible manipulator, which are global frame, body-fixed frame and co-rotational frame. The rigid-flexible coupling dynamic equation of the planar flexible manipulator is derived using the Hamilton's principle. Numerical simulations are carried out in the end of this paper to demonstrate the effectiveness of the proposed model. The simulation results indicate that the proposed model is efficient not only for small deformation but also for large deformation.

  10. Cinlar Subgrid Scale Model for Large Eddy Simulation

    CERN Document Server

    Kara, Rukiye

    2016-01-01

    We construct a new subgrid scale (SGS) stress model for representing the small scale effects in large eddy simulation (LES) of incompressible flows. We use the covariance tensor for representing the Reynolds stress and include Clark's model for the cross stress. The Reynolds stress is obtained analytically from Cinlar random velocity field, which is based on vortex structures observed in the ocean at the subgrid scale. The validity of the model is tested with turbulent channel flow computed in OpenFOAM. It is compared with the most frequently used Smagorinsky and one-equation eddy SGS models through DNS data.

  11. Including investment risk in large-scale power market models

    DEFF Research Database (Denmark)

    Lemming, Jørgen Kjærgaard; Meibom, P.

    2003-01-01

    can be included in large-scale partial equilibrium models of the power market. The analyses are divided into a part about risk measures appropriate for power market investors and a more technical part about the combination of a risk-adjustment model and a partial-equilibrium model. To illustrate......Long-term energy market models can be used to examine investments in production technologies, however, with market liberalisation it is crucial that such models include investment risks and investor behaviour. This paper analyses how the effect of investment risk on production technology selection...... the analyses quantitatively, a framework based on an iterative interaction between the equilibrium model and a separate risk-adjustment module was constructed. To illustrate the features of the proposed modelling approach we examined how uncertainty in demand and variable costs affects the optimal choice...

  12. The pig as a large animal model for characterization of host-pathogen interactions

    DEFF Research Database (Denmark)

    Skovgaard, Kerstin; Brogaard, Louise; Heegaard, Peter M. H.

    Large animal models are essential in understanding the mechanisms involved in human infectious disease. To study the expression of host and bacterial genes involved in defense and survival mechanisms, we analyzed lung tissue from pigs experimentally infected with the Gram-negative bacterium A...... experimental H1N2 virus infection of pigs, and found the regulation of several swine encoded miRNAs and cytokines to mimic key findings from influenza studies in human patients. By employing the pig as a model we were able to perform highly controlled experimental infections and to study changes of symptoms...

  13. Model Experiments for the Determination of Airflow in Large Spaces

    DEFF Research Database (Denmark)

    Nielsen, Peter V.

    Model experiments are one of the methods used for the determination of airflow in large spaces. This paper will discuss the formation of the governing dimensionless numbers. It is shown that experiments with a reduced scale often will necessitate a fully developed turbulence level of the flow....... Details of the flow from supply openings are very important for the determination of room air distribution. It is in some cases possible to make a simplified supply opening for the model experiment....

  14. Long-term complete remission in a patient with intravascular large B-cell lymphoma with central nervous system involvement

    Directory of Open Access Journals (Sweden)

    Sawada T

    2014-11-01

    Full Text Available Takeshi Sawada,1 Yasushi Omuro,1 Takeshi Kobayashi,2 Tunekazu Hishima,3 Fumiaki Koizumi,4 Yusuke Kanemasa,1 Tatsu Shimoyama,1 Eisaku Sasaki,1 Yoshiharu Maeda1 1Department of Chemotherapy, 2Department of Hematology, 3Department of Pathology, 4Department of Laboratory Medicine, Tokyo Metropolitan Cancer and Infectious Diseases Center, Komagome Hospital, Bunkyo-ku, Tokyo, Japan Abstract: This report describes a patient with intravascular large B-cell lymphoma (IVLBCL with central nervous system involvement at the time of diagnosis who achieved complete remission for over 5 years in response to therapy. The patient, a 71 year-old woman, was previously healthy with the exception of taking verapamil for paroxysmal supraventricular tachycardia. She had presented with pyrexia and gradually progressive anemia. Brain magnetic resonance imaging revealed an infarct-like lesion in the pons, although no paralysis was observed. She was diagnosed with IVLBCL on the basis of random skin biopsy. After eight cycles of rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone therapy, abnormal laboratory data had normalized, and no pontine lesion was evident on magnetic resonance imaging without receiving any intrathecal chemotherapy. IVLBCL is associated with poor prognosis, particularly in patients with central nervous system involvement. Early initiation of rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone therapy and drug interactions between anticancer agents and verapamil as a p-glycoprotein inhibitor were considered the possible reasons for favorable outcome in the present case. Keywords: intravascular large B-cell lymphoma, random skin biopsy, CNS involvement, rituximab, verapamil, blood–brain barrier

  15. A first large-scale flood inundation forecasting model

    Energy Technology Data Exchange (ETDEWEB)

    Schumann, Guy J-P; Neal, Jeffrey C.; Voisin, Nathalie; Andreadis, Konstantinos M.; Pappenberger, Florian; Phanthuwongpakdee, Kay; Hall, Amanda C.; Bates, Paul D.

    2013-11-04

    At present continental to global scale flood forecasting focusses on predicting at a point discharge, with little attention to the detail and accuracy of local scale inundation predictions. Yet, inundation is actually the variable of interest and all flood impacts are inherently local in nature. This paper proposes a first large scale flood inundation ensemble forecasting model that uses best available data and modeling approaches in data scarce areas and at continental scales. The model was built for the Lower Zambezi River in southeast Africa to demonstrate current flood inundation forecasting capabilities in large data-scarce regions. The inundation model domain has a surface area of approximately 170k km2. ECMWF meteorological data were used to force the VIC (Variable Infiltration Capacity) macro-scale hydrological model which simulated and routed daily flows to the input boundary locations of the 2-D hydrodynamic model. Efficient hydrodynamic modeling over large areas still requires model grid resolutions that are typically larger than the width of many river channels that play a key a role in flood wave propagation. We therefore employed a novel sub-grid channel scheme to describe the river network in detail whilst at the same time representing the floodplain at an appropriate and efficient scale. The modeling system was first calibrated using water levels on the main channel from the ICESat (Ice, Cloud, and land Elevation Satellite) laser altimeter and then applied to predict the February 2007 Mozambique floods. Model evaluation showed that simulated flood edge cells were within a distance of about 1 km (one model resolution) compared to an observed flood edge of the event. Our study highlights that physically plausible parameter values and satisfactory performance can be achieved at spatial scales ranging from tens to several hundreds of thousands of km2 and at model grid resolutions up to several km2. However, initial model test runs in forecast mode

  16. Application of Logic Models in a Large Scientific Research Program

    Science.gov (United States)

    O'Keefe, Christine M.; Head, Richard J.

    2011-01-01

    It is the purpose of this article to discuss the development and application of a logic model in the context of a large scientific research program within the Commonwealth Scientific and Industrial Research Organisation (CSIRO). CSIRO is Australia's national science agency and is a publicly funded part of Australia's innovation system. It conducts…

  17. Application of Logic Models in a Large Scientific Research Program

    Science.gov (United States)

    O'Keefe, Christine M.; Head, Richard J.

    2011-01-01

    It is the purpose of this article to discuss the development and application of a logic model in the context of a large scientific research program within the Commonwealth Scientific and Industrial Research Organisation (CSIRO). CSIRO is Australia's national science agency and is a publicly funded part of Australia's innovation system. It conducts…

  18. Large scale semantic 3D modeling of the urban landscape

    NARCIS (Netherlands)

    I. Esteban Lopez

    2012-01-01

    Modeling and understanding large urban areas is becoming an important topic in a world were everything is being digitized. A semantic and accurate 3D representation of a city can be used in many applications such as event and security planning and management, assisted navigation, autonomous operatio

  19. Large scale solar district heating. Evaluation, modelling and designing - Appendices

    Energy Technology Data Exchange (ETDEWEB)

    Heller, A.

    2000-07-01

    The appendices present the following: A) Cad-drawing of the Marstal CSHP design. B) Key values - large-scale solar heating in Denmark. C) Monitoring - a system description. D) WMO-classification of pyranometers (solarimeters). E) The computer simulation model in TRNSYS. F) Selected papers from the author. (EHS)

  20. Order reduction of large-scale linear oscillatory system models

    Energy Technology Data Exchange (ETDEWEB)

    Trudnowksi, D.J. (Pacific Northwest Lab., Richland, WA (United States))

    1994-02-01

    Eigen analysis and signal analysis techniques of deriving representations of power system oscillatory dynamics result in very high-order linear models. In order to apply many modern control design methods, the models must be reduced to a more manageable order while preserving essential characteristics. Presented in this paper is a model reduction method well suited for large-scale power systems. The method searches for the optimal subset of the high-order model that best represents the system. An Akaike information criterion is used to define the optimal reduced model. The method is first presented, and then examples of applying it to Prony analysis and eigenanalysis models of power systems are given.

  1. A numerical shoreline model for shorelines with large curvature

    DEFF Research Database (Denmark)

    Kærgaard, Kasper Hauberg; Fredsøe, Jørgen

    2013-01-01

    This paper presents a new numerical model for shoreline change which can be used to model the evolution of shorelines with large curvature. The model is based on a one-line formulation in terms of coordinates which follow the shape of the shoreline, instead of the more common approach where the two...... orthogonal horizontal directions are used. The volume error in the sediment continuity equation which is thereby introduced is removed through an iterative procedure. The model treats the shoreline changes by computing the sediment transport in a 2D coastal area model, and then integrating the sediment...... transport field across the coastal profile to obtain the longshore sediment transport variation along the shoreline. The model is used to compute the evolution of a shoreline with a 90° change in shoreline orientation; due to this drastic change in orientation a migrating shoreline spit develops...

  2. Dispersion modelling approaches for near road applications involving noise barriers

    Science.gov (United States)

    The talk will present comparisons with two datasets of the barrier algorithms implemented in two different dispersion models: US EPA’s R-LINE (a research dispersion modelling tool under development by the US EPA’s Office of Research and Development) and CERC’s A...

  3. Large scale dynamics of the Persistent Turning Walker model of fish behavior

    CERN Document Server

    Degond, Pierre

    2007-01-01

    This paper considers a new model of individual displacement, based on fish motion, the so-called Persistent Turning Walker (PTW) model, which involves an Ornstein-Uhlenbeck process on the curvature of the particle trajectory. The goal is to show that its large time and space scale dynamics is of diffusive type, and to provide an analytic expression of the diffusion coefficient. Two methods are investigated. In the first one, we compute the large time asymptotics of the variance of the individual stochastic trajectories. The second method is based on a diffusion approximation of the kinetic formulation of these stochastic trajectories. The kinetic model is a Fokker-Planck type equation posed in an extended phase-space involving the curvature among the kinetic variables. We show that both methods lead to the same value of the diffusion constant. We present some numerical simulations to illustrate the theoretical results.

  4. Mouse models for genes involved in impaired spermatogenesis.

    Science.gov (United States)

    O'Bryan, M K; de Kretser, D

    2006-02-01

    Since the introduction of molecular biology and gene ablation technologies there have been substantial advances in our understanding of how sperm are made and fertilization occurs. There have been at least 150 different models of specifically altered gene function produced that have resulted in male infertility spanning virtually all aspects of the spermatogenic, sperm maturation and fertilization processes. While each has, or potentially will reveal, novel aspects of these processes, there is still much of which we have little knowledge. The current review is by no means a comprehensive list of these mouse models, rather it gives an overview of the potential for such models which up to this point have generally been 'knockouts'; it presents alternative strategies for the production of new models and emphasizes the importance of thorough phenotypic analysis in order to extract a maximum amount of information from each model.

  5. The pig as a large animal model for influenza a virus infection

    DEFF Research Database (Denmark)

    Skovgaard, Kerstin; Brogaard, Louise; Larsen, Lars Erik

    infiltration of the respiratory system. This study aimed at providing a better understanding of the involvement of innate immune factors and non-coding RNA in blood leukocytes during influenza A virus infection. By using the pig as a model we were able to perform highly controlled experimental infections...... consolidate the pig as a valuable model for influenza A virus infection.......It is increasingly realized that large animal models like the pig are exceptionally human like and serve as an excellent model for disease and inflammation. Pigs are fully susceptible to human influenza, share many similarities with humans regarding lung physiology and innate immune cell...

  6. Pedigree models for complex human traits involving the mitochrondrial genome

    Energy Technology Data Exchange (ETDEWEB)

    Schork, N.J.; Guo, S.W. (Univ. of Michigan, Ann Arbor, MI (United States))

    1993-12-01

    Recent biochemical and molecular-genetic discoveries concerning variations in human mtDNA have suggested a role for mtDNA mutations in a number of human traits and disorders. Although the importance of these discoveries cannot be emphasized enough, the complex natures of mitochondrial biogenesis, mutant mtDNA phenotype expression, and the maternal inheritance pattern exhibited by mtDNA transmission make it difficult to develop models that can be used routinely in pedigree analyses to quantify and test hypotheses about the role of mtDNA in the expression of a trait. In the present paper, the authors describe complexities inherent in mitochondrial biogenesis and genetic transmission and show how these complexities can be incorporated into appropriate mathematical models. The authors offer a variety of likelihood-based models which account for the complexities discussed. The derivation of the models is meant to stimulate the construction of statistical tests for putative mtDNA contribution to a trait. Results of simulation studies which make use of the proposed models are described. The results of the simulation studies suggest that, although pedigree models of mtDNA effects can be reliable, success in mapping chromosomal determinants of a trait does not preclude the possibility that mtDNA determinants exist for the trait as well. Shortcomings inherent in the proposed models are described in an effort to expose areas in need of additional research. 58 refs., 5 figs., 2 tabs.

  7. Surrogate-based Multi-Objective Optimization and Uncertainty Quantification Methods for Large, Complex Geophysical Models

    Science.gov (United States)

    Gong, Wei; Duan, Qingyun

    2016-04-01

    Parameterization scheme has significant influence to the simulation ability of large, complex dynamic geophysical models, such as distributed hydrological models, land surface models, weather and climate models, etc. with the growing knowledge of physical processes, the dynamic geophysical models include more and more processes and producing more output variables. Consequently the parameter optimization / uncertainty quantification algorithms should also be multi-objective compatible. Although such algorithms have long been available, they usually require a large number of model runs and are therefore computationally expensive for large, complex dynamic models. In this research, we have developed surrogate-based multi-objective optimization method (MO-ASMO) and Markov Chain Monte Carlo method (MC-ASMO) for uncertainty quantification for these expensive dynamic models. The aim of MO-ASMO and MC-ASMO is to reduce the total number of model runs with appropriate adaptive sampling strategy assisted by surrogate modeling. Moreover, we also developed a method that can steer the search process with the help of prior parameterization scheme derived from the physical processes involved, so that all of the objectives can be improved simultaneously. The proposed algorithms have been evaluated with test problems and a land surface model - the Common Land Model (CoLM). The results demonstrated their effectiveness and efficiency.

  8. A COUPLED MORPHODYNAMIC MODEL FOR APPLICATIONS INVOLVING WETTING AND DRYING*

    Institute of Scientific and Technical Information of China (English)

    LIANG Qiuhua

    2011-01-01

    This work presents a new finite volume Godunov-type model for predicting morphological changes under the rapidly varying flood conditions with wetting and drying. The model solves the coupled shallow water and Exner equations, with the interface fluxes evaluated by an Harten-Lax-van Leer-Contact (HLLC) approximate Riemann solver. Well-balanced solution is achieved using the surface gradient method and wetting and drying are handled by a non-negative reconstruction approach. The new model is validated against several theoretical benchmark tests and promising results are obtained.

  9. Modeling and Compensatory Processes Underlying Involvement in Child Care among Kibbutz-Reared Fathers

    Science.gov (United States)

    Gaunt, Ruth; Bassi, Liat

    2012-01-01

    This study examined modeling and compensatory processes underlying the effects of an early paternal model on father involvement in child care. Drawing on social learning theory, it was hypothesized that father-son relationships would moderate the association between a father's involvement and his own father's involvement. A sample of 136 kibbutz…

  10. Large Scale Simulations of the Kinetic Ising Model

    Science.gov (United States)

    Münkel, Christian

    We present Monte Carlo simulation results for the dynamical critical exponent z of the two- and three-dimensional kinetic Ising model. The z-values were calculated from the magnetization relaxation from an ordered state into the equilibrium state at Tc for very large systems with up to (169984)2 and (3072)3 spins. To our knowledge, these are the largest Ising-systems simulated todate. We also report the successful simulation of very large lattices on a massively parallel MIMD computer with high speedups of approximately 1000 and an efficiency of about 0.93.

  11. Mathematical analysis and simulations involving chemotherapy and surgery on large human tumours under a suitable cell-kill functional response.

    Science.gov (United States)

    Rodrigues, Diego Samuel; de Arruda Mancera, Paulo Fernando

    2013-02-01

    Dosage and frequency of treatment schedules are important for successful chemotherapy. However, in this work we argue that cell-kill response and tumoral growth should not be seen as separate and therefore are essential in a mathematical cancer model. This paper presents a mathematical model for sequencing of cancer chemotherapy and surgery. Our purpose is to investigate treatments for large human tumours considering a suitable cell-kill dynamics. We use some biological and pharmacological data in a numerical approach, where drug administration occurs in cycles (periodic infusion) and surgery is performed instantaneously. Moreover, we also present an analysis of stability for a chemotherapeutic model with continuous drug administration. According to Norton and Simon [22], our results indicate that chemotherapy is less efficient in treating tumours that have reached a plateau level of growing and that a combination with surgical treatment can provide better outcomes.

  12. Modelling large floating bodies in urban area flash-floods via a Smoothed Particle Hydrodynamics model

    Science.gov (United States)

    Albano, Raffaele; Sole, Aurelia; Mirauda, Domenica; Adamowski, Jan

    2016-10-01

    Large debris, including vehicles parked along floodplains, can cause severe damage and significant loss of life during urban area flash-floods. In this study, the authors validated and applied the Smoothed Particle Hydrodynamics (SPH) model, developed in Amicarelli et al. (2015), which reproduces in 3D the dynamics of rigid bodies driven by free surface flows, to the design of flood mitigation measures. To validate the model, the authors compared the model's predictions to the results of an experimental setup, involving a dam breach that strikes two fixed obstacles and three transportable floating bodies. Given the accuracy of the results, in terms of water depth over time and the time history of the bodies' movements, the SPH model explored in this study was used to analyse the mitigation efficiency of a proposed structural intervention - the use of small barriers (groynes) to prevent the transport of floating bodies. Different groynes configurations were examined to identify the most appropriate design and layout for urban area flash-flood damage mitigation. The authors found that groynes positioned upstream and downstream of each floating body can be effective as a risk mitigation measure for damage resulting from their movement.

  13. Models for blisks with large blends and small mistuning

    Science.gov (United States)

    Tang, Weihan; Epureanu, Bogdan I.; Filippi, Sergio

    2017-03-01

    Small deviations of the structural properties of individual sectors of blisks, referred to as mistuning, can lead to localization of vibration energy and drastically increased forced responses. Similar phenomena are observed in blisks with large damages or repair blends. Such deviations are best studied statistically because they are random. In the absence of cyclic symmetry, the computational cost to predict the vibration behavior of blisks becomes prohibitively high. That has lead to the development of various reduced-order models (ROMs). Existing approaches are either for small mistuning, or are computationally expensive and thus not effective for statistical analysis. This paper discusses a reduced-order modeling method for blisks with both large and small mistuning, which requires low computational effort. This method utilizes the pristine, rogue and interface modal expansion (PRIME) method to model large blends. PRIME uses only sector-level cyclic modes strategically combined together to create a reduction basis which yields ROMs that efficiently and accurately model large mistuning. To model small mistuning, nodal energy weighted transformation (NEWT) is integrated with PRIME, resulting in N-PRIME, which requires only sector-level calculations to create a ROM which captures both small and large mistuning with minimized computational effort. The combined effects of large blends and small mistuning are studied using N-PRIME for a dual flow path system and for a conventional blisk. The accuracy of the N-PRIME method is validated against full-order finite element analyses for both natural and forced response computations, including displacement amplitudes and surface stresses. Results reveal that N-PRIME is capable of accurately predicting the dynamics of a blisk with severely large mistuning, along with small random mistuning throughout each sector. Also, N-PRIME can accurately capture modes with highly localized motions. A statistical analysis is performed to

  14. Application of simplified models to CO2 migration and immobilization in large-scale geological systems

    KAUST Repository

    Gasda, Sarah E.

    2012-07-01

    Long-term stabilization of injected carbon dioxide (CO 2) is an essential component of risk management for geological carbon sequestration operations. However, migration and trapping phenomena are inherently complex, involving processes that act over multiple spatial and temporal scales. One example involves centimeter-scale density instabilities in the dissolved CO 2 region leading to large-scale convective mixing that can be a significant driver for CO 2 dissolution. Another example is the potentially important effect of capillary forces, in addition to buoyancy and viscous forces, on the evolution of mobile CO 2. Local capillary effects lead to a capillary transition zone, or capillary fringe, where both fluids are present in the mobile state. This small-scale effect may have a significant impact on large-scale plume migration as well as long-term residual and dissolution trapping. Computational models that can capture both large and small-scale effects are essential to predict the role of these processes on the long-term storage security of CO 2 sequestration operations. Conventional modeling tools are unable to resolve sufficiently all of these relevant processes when modeling CO 2 migration in large-scale geological systems. Herein, we present a vertically-integrated approach to CO 2 modeling that employs upscaled representations of these subgrid processes. We apply the model to the Johansen formation, a prospective site for sequestration of Norwegian CO 2 emissions, and explore the sensitivity of CO 2 migration and trapping to subscale physics. Model results show the relative importance of different physical processes in large-scale simulations. The ability of models such as this to capture the relevant physical processes at large spatial and temporal scales is important for prediction and analysis of CO 2 storage sites. © 2012 Elsevier Ltd.

  15. Modeling of nonlinear responses for reciprocal transducers involving polarization switching

    DEFF Research Database (Denmark)

    Willatzen, Morten; Wang, Linxiang

    2007-01-01

    Nonlinearities and hysteresis effects in a reciprocal PZT transducer are examined by use of a dynamical mathematical model on the basis of phase-transition theory. In particular, we consider the perovskite piezoelectric ceramic in which the polarization process in the material can be modeled....... We present numerical results for the reciprocal-transducer system and identify the influence of nonlinearities on the system dynamics at high and low frequency as well as electrical impedance effects due to tuning by a series inductance. It is found that nonlinear effects are not important at high...... by Landau theory for the first-order phase transformation, in which each polarization state is associated with a minimum of the Landau free-energy function. Nonlinear constitutive laws are obtained by using thermodynamical equilibrium conditions, and hysteretic behavior of the material can be modeled...

  16. A large deformation viscoelastic model for double-network hydrogels

    Science.gov (United States)

    Mao, Yunwei; Lin, Shaoting; Zhao, Xuanhe; Anand, Lallit

    2017-03-01

    We present a large deformation viscoelasticity model for recently synthesized double network hydrogels which consist of a covalently-crosslinked polyacrylamide network with long chains, and an ionically-crosslinked alginate network with short chains. Such double-network gels are highly stretchable and at the same time tough, because when stretched the crosslinks in the ionically-crosslinked alginate network rupture which results in distributed internal microdamage which dissipates a substantial amount of energy, while the configurational entropy of the covalently-crosslinked polyacrylamide network allows the gel to return to its original configuration after deformation. In addition to the large hysteresis during loading and unloading, these double network hydrogels also exhibit a substantial rate-sensitive response during loading, but exhibit almost no rate-sensitivity during unloading. These features of large hysteresis and asymmetric rate-sensitivity are quite different from the response of conventional hydrogels. We limit our attention to modeling the complex viscoelastic response of such hydrogels under isothermal conditions. Our model is restricted in the sense that we have limited our attention to conditions under which one might neglect any diffusion of the water in the hydrogel - as might occur when the gel has a uniform initial value of the concentration of water, and the mobility of the water molecules in the gel is low relative to the time scale of the mechanical deformation. We also do not attempt to model the final fracture of such double-network hydrogels.

  17. Large Animal Models for Foamy Virus Vector Gene Therapy

    Directory of Open Access Journals (Sweden)

    Peter A. Horn

    2012-12-01

    Full Text Available Foamy virus (FV vectors have shown great promise for hematopoietic stem cell (HSC gene therapy. Their ability to efficiently deliver transgenes to multi-lineage long-term repopulating cells in large animal models suggests they will be effective for several human hematopoietic diseases. Here, we review FV vector studies in large animal models, including the use of FV vectors with the mutant O6-methylguanine-DNA methyltransferase, MGMTP140K to increase the number of genetically modified cells after transplantation. In these studies, FV vectors have mediated efficient gene transfer to polyclonal repopulating cells using short ex vivo transduction protocols designed to minimize the negative effects of ex vivo culture on stem cell engraftment. In this regard, FV vectors appear superior to gammaretroviral vectors, which require longer ex vivo culture to effect efficient transduction. FV vectors have also compared favorably with lentiviral vectors when directly compared in the dog model. FV vectors have corrected leukocyte adhesion deficiency and pyruvate kinase deficiency in the dog large animal model. FV vectors also appear safer than gammaretroviral vectors based on a reduced frequency of integrants near promoters and also near proto-oncogenes in canine repopulating cells. Together, these studies suggest that FV vectors should be highly effective for several human hematopoietic diseases, including those that will require relatively high percentages of gene-modified cells to achieve clinical benefit.

  18. Large eddy simulation modelling of combustion for propulsion applications.

    Science.gov (United States)

    Fureby, C

    2009-07-28

    Predictive modelling of turbulent combustion is important for the development of air-breathing engines, internal combustion engines, furnaces and for power generation. Significant advances in modelling non-reactive turbulent flows are now possible with the development of large eddy simulation (LES), in which the large energetic scales of the flow are resolved on the grid while modelling the effects of the small scales. Here, we discuss the use of combustion LES in predictive modelling of propulsion applications such as gas turbine, ramjet and scramjet engines. The LES models used are described in some detail and are validated against laboratory data-of which results from two cases are presented. These validated LES models are then applied to an annular multi-burner gas turbine combustor and a simplified scramjet combustor, for which some additional experimental data are available. For these cases, good agreement with the available reference data is obtained, and the LES predictions are used to elucidate the flow physics in such devices to further enhance our knowledge of these propulsion systems. Particular attention is focused on the influence of the combustion chemistry, turbulence-chemistry interaction, self-ignition, flame holding burner-to-burner interactions and combustion oscillations.

  19. Sustainability of an energy conversion system in Canada involving large-scale integrated hydrogen production using solid fuels

    Directory of Open Access Journals (Sweden)

    Nirmal V. Gnanapragasam, Bale V. Reddy, Marc A. Rosen

    2011-01-01

    Full Text Available The sustainability of a large-scale hydrogen production system is assessed qualitatively. The system uses solid fuels and aims to increase the sustainability of the energy system in Canada through the use of alternative energy forms. The system involves significant technology integration, with various energy conversion processes (e.g., gasification, chemical looping combustion, anaerobic digestion, combustion power cycles-electrolysis and solar-thermal convertors interconnected to increase the utilization of solid fuels as much as feasible in a sustainable manner within cost, environmental and other constraints. The qualitative analysis involves ten different indicators for each of the three dimensions of sustainability: ecology, sociology and technology, applied to each process in the system and assessed based on a ten-point quality scale. The results indicate that biomasses have better sustainability than coals while newer secondary processes are essential for primary conversion to be sustainable, especially when using coals. Also, new developments in CO2 use (for algae-to-oil and commercial applications and storage will in time help improve sustainability.

  20. The Coriolis Effect: A Model for Student Involvement

    Science.gov (United States)

    Exline, Joseph D.

    1977-01-01

    Lists materials and procedures for constructing a model that demonstrates certain aspects of the Coriolis effect. Materials include an electric drill motor, voltage control, toy dart gun and darts, wood blocks of varying dimensions. Includes description of an experiment illustrating relationship between speed of rotation and amount of apparent…

  1. Acute strength exercise and the involvement of small or large muscle mass on plasma brain-derived neurotrophic factor levels

    Directory of Open Access Journals (Sweden)

    Paulo Roberto Correia

    2010-01-01

    Full Text Available OBJECTIVE: Blood neurotrophins, such as the brain-derived neurotrophic factor, are considered to be of great importance in mediating the benefits of physical exercise. In this study, the effect of acute strength exercise and the involvement of small versus large muscle mass on the levels of plasma brain-derived neurotrophic factor were evaluated in healthy individuals. METHODS: The concentric strengths of knee (large and elbow (small flexor and extensor muscles were measured on two separate days. Venous blood samples were obtained from 16 healthy subjects before and after exercise. RESULTS: The levels of brain-derived neurotrophic factor in the plasma did not significantly increase after both arm and leg exercise. There was no significant difference in the plasma levels of the brain-derived neurotrophic factor in the arms and legs. CONCLUSION: The present results demonstrate that acute strength exercise does not induce significant alterations in the levels of brain-derived neurotrophic factor plasma concentrations in healthy individuals. Considering that its levels may be affected by various factors, such as exercise, these findings suggest that the type of exercise program may be a decisive factor in altering peripheral brain-derived neurotrophic factor.

  2. Mechanism involved in the UCB neurotoxicity on cellular models

    OpenAIRE

    Giraudi, Pablo Jose'

    2009-01-01

    Summary This doctoral thesis covers three years period (2006-2008) during which I have investigated the bilirubin neurotoxicity in the neuroblastoma SH-SY5Y cell line, a neuronal cell model widely used in the study of the pathogenesis and in the development of new therapeutic compounds for neurodegenerative diseases. In the first chapter is summarized the current knowledge about bilirubin chemistry and metabolism including disorders of bilirubin metabolism and the neuronal disturbanc...

  3. Soil carbon management in large-scale Earth system modelling

    DEFF Research Database (Denmark)

    Olin, S.; Lindeskog, M.; Pugh, T. A. M.;

    2015-01-01

    Croplands are vital ecosystems for human well-being and provide important ecosystem services such as crop yields, retention of nitrogen and carbon storage. On large (regional to global)-scale levels, assessment of how these different services will vary in space and time, especially in response to...... modelling C–N interactions in agricultural ecosystems under future environmental change and the effects these have on terrestrial biogeochemical cycles....

  4. Considerations in Scale-Modeling of Large Urban Fires

    Science.gov (United States)

    1984-11-15

    is inconsequential and that all molecular transport processes are unimportant). The nondimensional parameters to be preserved between the model and...fuel bed. Parker, Corlett and B. T. Lee [!3] also come to a similar conclusion based * on the following two points. First, in large fires, molecular ...to USDA Forest Service, Prepared by Instituto Nacional "de Tecnica Aeroespacial, Madrid, Spain, (May, 1967). "" 57. S.L. Lee and G.M. Hellman

  5. One-dimensional adhesion model for large scale structures

    Directory of Open Access Journals (Sweden)

    Kayyunnapara Thomas Joseph

    2010-05-01

    Full Text Available We discuss initial value problems and initial boundary value problems for some systems of partial differential equations appearing in the modelling for the large scale structure formation in the universe. We restrict the initial data to be bounded measurable and locally bounded variation function and use Volpert product to justify the product which appear in the equation. For more general initial data in the class of generalized functions of Colombeau, we construct the solution in the sense of association.

  6. From Large to Small Scales: Global Models of the ISM

    CERN Document Server

    D'Avillez, M A

    2004-01-01

    We review large scale modelling of the ISM with emphasis on the importance to include the disk-halo-disk duty cycle and to use a dynamical refinement of the grid (in regions where steep variations of density and pressure occur) for a realistic modelling of the ISM. We also discuss the necessity of convergence of the simulation results by comparing 0.625, 1.25 and 2.5 pc resolution simulations and show that a minimum grid resolution of 1.25 pc is required for quantitatively reliable results, as there is a rapid convergence for $\\Delta x \\leq 1.1$ pc.

  7. Supervision in Factor Models Using a Large Number of Predictors

    DEFF Research Database (Denmark)

    Boldrini, Lorenzo; Hillebrand, Eric Tobias

    In this paper we investigate the forecasting performance of a particular factor model (FM) in which the factors are extracted from a large number of predictors. We use a semi-parametric state-space representation of the FM in which the forecast objective, as well as the factors, is included.......g. a standard dynamic factor model with separate forecast and state equations....... in the state vector. The factors are informed of the forecast target (supervised) through the state equation dynamics. We propose a way to assess the contribution of the forecast objective on the extracted factors that exploits the Kalman filter recursions. We forecast one target at a time based...

  8. Non-Standard Models, Solar Neutrinos, and Large \\theta_{13}

    CERN Document Server

    Bonventre, R; Klein, J R; Gann, G D Orebi; Seibert, S; Wasalski, O

    2013-01-01

    Solar neutrino experiments have yet to see directly the transition region between matter-enhanced and vacuum oscillations. The transition region is particularly sensitive to models of non-standard neutrino interactions and propagation. We examine several such non-standard models, which predict a lower-energy transition region and a flatter survival probability for the ^{8}B solar neutrinos than the standard large-mixing angle (LMA) model. We find that while some of the non-standard models provide a better fit to the solar neutrino data set, the large measured value of \\theta_{13} and the size of the experimental uncertainties lead to a low statistical significance for these fits. We have also examined whether simple changes to the solar density profile can lead to a flatter ^{8}B survival probability than the LMA prediction, but find that this is not the case for reasonable changes. We conclude that the data in this critical region is still too poor to determine whether any of these models, or LMA, is the bes...

  9. Large-N Analysis of Three Dimensional Nonlinear Sigma Models

    CERN Document Server

    Higashijima, K; Tsuzuki, M; Higashijima, Kiyoshi; Itou, Etsuko; Tsuzuki, Makoto

    2005-01-01

    Non-perturbative renormalization group approach suggests that a large class of nonlinear sigma models are renormalizable in three dimensional space-time, while they are non-renormalizable in perturbation theory. ${\\cal N}=2$ supersymmetric nonlinear sigma models whose target spaces are Einstein-K\\"{a}hler manifolds with positive scalar curvature belongs to this class. hermitian symmetric spaces, being homogeneous, are specially simple examples of these manifolds. To find an independent evidence of the nonperturbative renormalizability of these models, the large N method, another nonperturbative method, is applied to 3-dimensional ${\\cal N}=2$ supersymmetric nonlinear sigma models on the target spaces $CP^{N-1}=SU(N)/[SU(N-1)\\times U(1)]$ and $Q^{N-2}=SO(N)/[SO(N-2)\\times SO(2)]$, two typical examples of hermitian symmetric spaces. We find that $\\beta$ functions in these models agree with the results of the nonperturbative renormalization group approach in the next-to-leading order of 1/N expansion, and have n...

  10. A family of dynamic models for large-eddy simulation

    Science.gov (United States)

    Carati, D.; Jansen, K.; Lund, T.

    1995-01-01

    Since its first application, the dynamic procedure has been recognized as an effective means to compute rather than prescribe the unknown coefficients that appear in a subgrid-scale model for Large-Eddy Simulation (LES). The dynamic procedure is usually used to determine the nondimensional coefficient in the Smagorinsky (1963) model. In reality the procedure is quite general and it is not limited to the Smagorinsky model by any theoretical or practical constraints. The purpose of this note is to consider a generalized family of dynamic eddy viscosity models that do not necessarily rely on the local equilibrium assumption built into the Smagorinsky model. By invoking an inertial range assumption, it will be shown that the coefficients in the new models need not be nondimensional. This additional degree of freedom allows the use of models that are scaled on traditionally unknown quantities such as the dissipation rate. In certain cases, the dynamic models with dimensional coefficients are simpler to implement, and allow for a 30% reduction in the number of required filtering operations.

  11. Multiresolution comparison of precipitation datasets for large-scale models

    Science.gov (United States)

    Chun, K. P.; Sapriza Azuri, G.; Davison, B.; DeBeer, C. M.; Wheater, H. S.

    2014-12-01

    Gridded precipitation datasets are crucial for driving large-scale models which are related to weather forecast and climate research. However, the quality of precipitation products is usually validated individually. Comparisons between gridded precipitation products along with ground observations provide another avenue for investigating how the precipitation uncertainty would affect the performance of large-scale models. In this study, using data from a set of precipitation gauges over British Columbia and Alberta, we evaluate several widely used North America gridded products including the Canadian Gridded Precipitation Anomalies (CANGRD), the National Center for Environmental Prediction (NCEP) reanalysis, the Water and Global Change (WATCH) project, the thin plate spline smoothing algorithms (ANUSPLIN) and Canadian Precipitation Analysis (CaPA). Based on verification criteria for various temporal and spatial scales, results provide an assessment of possible applications for various precipitation datasets. For long-term climate variation studies (~100 years), CANGRD, NCEP, WATCH and ANUSPLIN have different comparative advantages in terms of their resolution and accuracy. For synoptic and mesoscale precipitation patterns, CaPA provides appealing performance of spatial coherence. In addition to the products comparison, various downscaling methods are also surveyed to explore new verification and bias-reduction methods for improving gridded precipitation outputs for large-scale models.

  12. Binary choices in small and large groups: A unified model

    Science.gov (United States)

    Bischi, Gian-Italo; Merlone, Ugo

    2010-02-01

    Two different ways to model the diffusion of alternative choices within a population of individuals in the presence of social externalities are known in the literature. While Galam’s model of rumors spreading considers a majority rule for interactions in several groups, Schelling considers individuals interacting in one large group, with payoff functions that describe how collective choices influence individual preferences. We incorporate these two approaches into a unified general discrete-time dynamic model for studying individual interactions in variously sized groups. We first illustrate how the two original models can be obtained as particular cases of the more general model we propose, then we show how several other situations can be analyzed. The model we propose goes beyond a theoretical exercise as it allows modeling situations which are relevant in economic and social systems. We consider also other aspects such as the propensity to switch choices and the behavioral momentum, and show how they may affect the dynamics of the whole population.

  13. Sleeping Beauty mouse models identify candidate genes involved in gliomagenesis.

    Science.gov (United States)

    Vyazunova, Irina; Maklakova, Vilena I; Berman, Samuel; De, Ishani; Steffen, Megan D; Hong, Won; Lincoln, Hayley; Morrissy, A Sorana; Taylor, Michael D; Akagi, Keiko; Brennan, Cameron W; Rodriguez, Fausto J; Collier, Lara S

    2014-01-01

    Genomic studies of human high-grade gliomas have discovered known and candidate tumor drivers. Studies in both cell culture and mouse models have complemented these approaches and have identified additional genes and processes important for gliomagenesis. Previously, we found that mobilization of Sleeping Beauty transposons in mice ubiquitously throughout the body from the Rosa26 locus led to gliomagenesis with low penetrance. Here we report the characterization of mice in which transposons are mobilized in the Glial Fibrillary Acidic Protein (GFAP) compartment. Glioma formation in these mice did not occur on an otherwise wild-type genetic background, but rare gliomas were observed when mobilization occurred in a p19Arf heterozygous background. Through cloning insertions from additional gliomas generated by transposon mobilization in the Rosa26 compartment, several candidate glioma genes were identified. Comparisons to genetic, epigenetic and mRNA expression data from human gliomas implicates several of these genes as tumor suppressor genes and oncogenes in human glioblastoma.

  14. ARCHITECTURAL LARGE CONSTRUCTED ENVIRONMENT. MODELING AND INTERACTION USING DYNAMIC SIMULATIONS

    Directory of Open Access Journals (Sweden)

    P. Fiamma

    2012-09-01

    Full Text Available How to use for the architectural design, the simulation coming from a large size data model? The topic is related to the phase coming usually after the acquisition of the data, during the construction of the model and especially after, when designers must have an interaction with the simulation, in order to develop and verify their idea. In the case of study, the concept of interaction includes the concept of real time "flows". The work develops contents and results that can be part of the large debate about the current connection between "architecture" and "movement". The focus of the work, is to realize a collaborative and participative virtual environment on which different specialist actors, client and final users can share knowledge, targets and constraints to better gain the aimed result. The goal is to have used a dynamic micro simulation digital resource that allows all the actors to explore the model in powerful and realistic way and to have a new type of interaction in a complex architectural scenario. On the one hand, the work represents a base of knowledge that can be implemented more and more; on the other hand the work represents a dealt to understand the large constructed architecture simulation as a way of life, a way of being in time and space. The architectural design before, and the architectural fact after, both happen in a sort of "Spatial Analysis System". The way is open to offer to this "system", knowledge and theories, that can support architectural design work for every application and scale. We think that the presented work represents a dealt to understand the large constructed architecture simulation as a way of life, a way of being in time and space. Architecture like a spatial configuration, that can be reconfigurable too through designing.

  15. Challenges of Modeling Flood Risk at Large Scales

    Science.gov (United States)

    Guin, J.; Simic, M.; Rowe, J.

    2009-04-01

    Flood risk management is a major concern for many nations and for the insurance sector in places where this peril is insured. A prerequisite for risk management, whether in the public sector or in the private sector is an accurate estimation of the risk. Mitigation measures and traditional flood management techniques are most successful when the problem is viewed at a large regional scale such that all inter-dependencies in a river network are well understood. From an insurance perspective the jury is still out there on whether flood is an insurable peril. However, with advances in modeling techniques and computer power it is possible to develop models that allow proper risk quantification at the scale suitable for a viable insurance market for flood peril. In order to serve the insurance market a model has to be event-simulation based and has to provide financial risk estimation that forms the basis for risk pricing, risk transfer and risk management at all levels of insurance industry at large. In short, for a collection of properties, henceforth referred to as a portfolio, the critical output of the model is an annual probability distribution of economic losses from a single flood occurrence (flood event) or from an aggregation of all events in any given year. In this paper, the challenges of developing such a model are discussed in the context of Great Britain for which a model has been developed. The model comprises of several, physically motivated components so that the primary attributes of the phenomenon are accounted for. The first component, the rainfall generator simulates a continuous series of rainfall events in space and time over thousands of years, which are physically realistic while maintaining the statistical properties of rainfall at all locations over the model domain. A physically based runoff generation module feeds all the rivers in Great Britain, whose total length of stream links amounts to about 60,000 km. A dynamical flow routing

  16. Large-scale Modeling of Inundation in the Amazon Basin

    Science.gov (United States)

    Luo, X.; Li, H. Y.; Getirana, A.; Leung, L. R.; Tesfa, T. K.

    2015-12-01

    Flood events have impacts on the exchange of energy, water and trace gases between land and atmosphere, hence potentially affecting the climate. The Amazon River basin is the world's largest river basin. Seasonal floods occur in the Amazon Basin each year. The basin being characterized by flat gradients, backwater effects are evident in the river dynamics. This factor, together with large uncertainties in river hydraulic geometry, surface topography and other datasets, contribute to difficulties in simulating flooding processes over this basin. We have developed a large-scale inundation scheme in the framework of the Model for Scale Adaptive River Transport (MOSART) river routing model. Both the kinematic wave and the diffusion wave routing methods are implemented in the model. A new process-based algorithm is designed to represent river channel - floodplain interactions. Uncertainties in the input datasets are partly addressed through model calibration. We will present the comparison of simulated results against satellite and in situ observations and analysis to understand factors that influence inundation processes in the Amazon Basin.

  17. Analytical modeling of large-angle CMBR anisotropies from textures

    CERN Document Server

    Magueijo, J

    1995-01-01

    We propose an analytic method for predicting the large angle CMBR temperature fluctuations induced by model textures. The model makes use of only a small number of phenomenological parameters which ought to be measured from simple simulations. We derive semi-analytically the C^l-spectrum for 2\\leq l\\leq 30 together with its associated non-Gaussian cosmic variance error bars. A slightly tilted spectrum with an extra suppression at low l is found, and we investigate the dependence of the tilt on the parameters of the model. We also produce a prediction for the two point correlation function. We find a high level of cosmic confusion between texture scenarios and standard inflationary theories in any of these quantities. However, we discover that a distinctive non-Gaussian signal ought to be expected at low l, reflecting the prominent effect of the last texture in these multipoles.

  18. Modeling The Large Scale Bias of Neutral Hydrogen

    CERN Document Server

    Marin, Felipe; Seo, Hee-Jong; Vallinotto, Alberto

    2009-01-01

    We present analytical estimates of the large scale bias of neutral Hydrogen (HI) based on the Halo Occupation Distribution formalism. We use a simple, non-parametric model which monotonically relates the total mass of a halo with its HI mass at zero redshift; for earlier times we assume limiting models for the HI density parameter evolution, consistent with the data presently available, as well as two main scenarios for the evolution of our HI mass - Halo mass relation. We find that both the linear and the first non-linear bias terms exhibit a remarkable evolution with redshift, regardless of the specific limiting model assumed for the HI evolution. These analytical predictions are then shown to be consistent with measurements performed on the Millennium Simulation. Additionally, we show that this strong bias evolution does not sensibly affect the measurement of the HI Power Spectrum.

  19. Sleeping Beauty mouse models identify candidate genes involved in gliomagenesis.

    Directory of Open Access Journals (Sweden)

    Irina Vyazunova

    Full Text Available Genomic studies of human high-grade gliomas have discovered known and candidate tumor drivers. Studies in both cell culture and mouse models have complemented these approaches and have identified additional genes and processes important for gliomagenesis. Previously, we found that mobilization of Sleeping Beauty transposons in mice ubiquitously throughout the body from the Rosa26 locus led to gliomagenesis with low penetrance. Here we report the characterization of mice in which transposons are mobilized in the Glial Fibrillary Acidic Protein (GFAP compartment. Glioma formation in these mice did not occur on an otherwise wild-type genetic background, but rare gliomas were observed when mobilization occurred in a p19Arf heterozygous background. Through cloning insertions from additional gliomas generated by transposon mobilization in the Rosa26 compartment, several candidate glioma genes were identified. Comparisons to genetic, epigenetic and mRNA expression data from human gliomas implicates several of these genes as tumor suppressor genes and oncogenes in human glioblastoma.

  20. Sleeping Beauty Mouse Models Identify Candidate Genes Involved in Gliomagenesis

    Science.gov (United States)

    Vyazunova, Irina; Maklakova, Vilena I.; Berman, Samuel; De, Ishani; Steffen, Megan D.; Hong, Won; Lincoln, Hayley; Morrissy, A. Sorana; Taylor, Michael D.; Akagi, Keiko; Brennan, Cameron W.; Rodriguez, Fausto J.; Collier, Lara S.

    2014-01-01

    Genomic studies of human high-grade gliomas have discovered known and candidate tumor drivers. Studies in both cell culture and mouse models have complemented these approaches and have identified additional genes and processes important for gliomagenesis. Previously, we found that mobilization of Sleeping Beauty transposons in mice ubiquitously throughout the body from the Rosa26 locus led to gliomagenesis with low penetrance. Here we report the characterization of mice in which transposons are mobilized in the Glial Fibrillary Acidic Protein (GFAP) compartment. Glioma formation in these mice did not occur on an otherwise wild-type genetic background, but rare gliomas were observed when mobilization occurred in a p19Arf heterozygous background. Through cloning insertions from additional gliomas generated by transposon mobilization in the Rosa26 compartment, several candidate glioma genes were identified. Comparisons to genetic, epigenetic and mRNA expression data from human gliomas implicates several of these genes as tumor suppressor genes and oncogenes in human glioblastoma. PMID:25423036

  1. Equilibrium models of coronal loops that involve curvature and buoyancy

    CERN Document Server

    Hindman, Bradley W

    2013-01-01

    We construct magnetostatic models of coronal loops in which the thermodynamics of the loop is fully consistent with the shape and geometry of the loop. This is achieved by treating the loop as a thin, compact, magnetic fibril that is a small departure from a force-free state. The density along the loop is related to the loop's curvature by requiring that the Lorentz force arising from this deviation is balanced by buoyancy. This equilibrium, coupled with hydrostatic balance and the ideal gas law, then connects the temperature of the loop with the curvature of the loop without resorting to a detailed treatment of heating and cooling. We present two example solutions: one with a spatially invariant magnetic Bond number (the dimensionless ratio of buoyancy to Lorentz forces) and the other with a constant radius of curvature of the loop's axis. We find that the density and temperature profiles are quite sensitive to curvature variations along the loop, even for loops with similar aspect ratios.

  2. Equilibrium Models of Coronal Loops That Involve Curvature and Buoyancy

    Science.gov (United States)

    Hindman, Bradley W.; Jain, Rekha

    2013-12-01

    We construct magnetostatic models of coronal loops in which the thermodynamics of the loop is fully consistent with the shape and geometry of the loop. This is achieved by treating the loop as a thin, compact, magnetic fibril that is a small departure from a force-free state. The density along the loop is related to the loop's curvature by requiring that the Lorentz force arising from this deviation is balanced by buoyancy. This equilibrium, coupled with hydrostatic balance and the ideal gas law, then connects the temperature of the loop with the curvature of the loop without resorting to a detailed treatment of heating and cooling. We present two example solutions: one with a spatially invariant magnetic Bond number (the dimensionless ratio of buoyancy to Lorentz forces) and the other with a constant radius of the curvature of the loop's axis. We find that the density and temperature profiles are quite sensitive to curvature variations along the loop, even for loops with similar aspect ratios.

  3. The independent spreaders involved SIR Rumor model in complex networks

    Science.gov (United States)

    Qian, Zhen; Tang, Shaoting; Zhang, Xiao; Zheng, Zhiming

    2015-07-01

    Recent studies of rumor or information diffusion process in complex networks show that in contrast to traditional comprehension, individuals who participate in rumor spreading within one network do not always get the rumor from their neighbors. They can obtain the rumor from different sources like online social networks and then publish it on their personal sites. In our paper, we discuss this phenomenon in complex networks by adopting the concept of independent spreaders. Rather than getting the rumor from neighbors, independent spreaders learn it from other channels. We further develop the classic "ignorant-spreaders-stiflers" or SIR model of rumor diffusion process in complex networks. A steady-state analysis is conducted to investigate the final spectrum of the rumor spreading under various spreading rate, stifling rate, density of independent spreaders and average degree of the network. Results show that independent spreaders effectively enhance the rumor diffusion process, by delivering the rumor to regions far away from the current rumor infected regions. And though the rumor spreading process in SF networks is faster than that in ER networks, the final size of rumor spreading in ER networks is larger than that in SF networks.

  4. Efficiently parallelized modeling of tightly focused, large bandwidth laser pulses

    CERN Document Server

    Dumont, Joey; Lefebvre, Catherine; Gagnon, Denis; MacLean, Steve

    2016-01-01

    The Stratton-Chu integral representation of electromagnetic fields is used to study the spatio-temporal properties of large bandwidth laser pulses focused by high numerical aperture mirrors. We review the formal aspects of the derivation of diffraction integrals from the Stratton-Chu representation and discuss the use of the Hadamard finite part in the derivation of the physical optics approximation. By analyzing the formulation we show that, for the specific case of a parabolic mirror, the integrands involved in the description of the reflected field near the focal spot do not possess the strong oscillations characteristic of diffraction integrals. Consequently, the integrals can be evaluated with simple and efficient quadrature methods rather than with specialized, more costly approaches. We report on the development of an efficiently parallelized algorithm that evaluates the Stratton-Chu diffraction integrals for incident fields of arbitrary temporal and spatial dependence. We use our method to show that t...

  5. Dynamical modeling and analysis of large cellular regulatory networks

    Science.gov (United States)

    Bérenguier, D.; Chaouiya, C.; Monteiro, P. T.; Naldi, A.; Remy, E.; Thieffry, D.; Tichit, L.

    2013-06-01

    The dynamical analysis of large biological regulatory networks requires the development of scalable methods for mathematical modeling. Following the approach initially introduced by Thomas, we formalize the interactions between the components of a network in terms of discrete variables, functions, and parameters. Model simulations result in directed graphs, called state transition graphs. We are particularly interested in reachability properties and asymptotic behaviors, which correspond to terminal strongly connected components (or "attractors") in the state transition graph. A well-known problem is the exponential increase of the size of state transition graphs with the number of network components, in particular when using the biologically realistic asynchronous updating assumption. To address this problem, we have developed several complementary methods enabling the analysis of the behavior of large and complex logical models: (i) the definition of transition priority classes to simplify the dynamics; (ii) a model reduction method preserving essential dynamical properties, (iii) a novel algorithm to compact state transition graphs and directly generate compressed representations, emphasizing relevant transient and asymptotic dynamical properties. The power of an approach combining these different methods is demonstrated by applying them to a recent multilevel logical model for the network controlling CD4+ T helper cell response to antigen presentation and to a dozen cytokines. This model accounts for the differentiation of canonical Th1 and Th2 lymphocytes, as well as of inflammatory Th17 and regulatory T cells, along with many hybrid subtypes. All these methods have been implemented into the software GINsim, which enables the definition, the analysis, and the simulation of logical regulatory graphs.

  6. Crime scene investigation involving a large turbidite - a 1h-teaching unit in Limnogeology/Sedimentology

    Science.gov (United States)

    Gilli, Adrian; Kremer, Katrina

    2017-04-01

    In 1996, a dead corpse (named „Brienzi") was found at the banks of the picturesque Lake Brienz in the Bernese Alps/Switzerland. What is the origin of this corpse and which chain of events lead to this crime scene? This is the starting position for a 1h exercise/game for undergraduate students in Earth Sciences/Geosciences.The students are provided with a wealth of evidences like statements from people potentially involved in the case, age data on the human corpse and monitoring data from the lake and its surroundings. The students are guided through the game step by step. After solving a task, the students get a feedback and can check if they were correct with their interpretation. Interestingly for earth science students, a lacustrine mass moment plays an important role in these investigations, but more should not be given at this point. In this exercise, we can also check if the teached content of the previous lessons have been acquired correctly by the students, as it deals with diverse limnogeological and sedimentological aspects. The game is strongly based on a study of Girardclos et al. (2007) and uses their argumentation for the occurrence of a large mass movement in Lake Brienz in 1996. A copy of the game is available by the author upon request. Reference: Girardclos, S., Schmidt, O.T., Sturm, M., Ariztegui, D., Pugin, A. and Anselmetti, F.S., 2007, The 1996 AD delta collapse and large turbidite in Lake Brienz. Marine Geology, 241, pp.137-154. doi:10.1016/j.margeo.2007.03.011

  7. Large-Scale Tests of the DGP Model

    CERN Document Server

    Song, Y S; Hu, W; Song, Yong-Seon; Sawicki, Ignacy; Hu, Wayne

    2006-01-01

    The self-accelerating braneworld model (DGP) can be tested from measurements of the expansion history of the universe and the formation of structure. Current constraints on the expansion history from supernova luminosity distances, the CMB, and the Hubble constant exclude the simplest flat DGP model at about 3sigma. The best-fit open DGP model is, however, only a marginally poorer fit to the data than flat LCDM. Its substantially different expansion history raises structure formation challenges for the model. A dark-energy model with the same expansion history would predict a highly significant discrepancy with the baryon oscillation measurement due the high Hubble constant required and a large enhancement of CMB anisotropies at the lowest multipoles due to the ISW effect. For the DGP model to satisfy these constraints new gravitational phenomena would have to appear at the non-linear and cross-over scales respectively. A prediction of the DGP expansion history in a region where the phenomenology is well unde...

  8. Improved engine wall models for Large Eddy Simulation (LES)

    Science.gov (United States)

    Plengsaard, Chalearmpol

    Improved wall models for Large Eddy Simulation (LES) are presented in this research. The classical Werner-Wengle (WW) wall shear stress model is used along with near-wall sub-grid scale viscosity. A sub-grid scale turbulent kinetic energy is employed in a model for the eddy viscosity. To gain better heat flux results, a modified classical variable-density wall heat transfer model is also used. Because no experimental wall shear stress results are available in engines, the fully turbulent developed flow in a square duct is chosen to validate the new wall models. The model constants in the new wall models are set to 0.01 and 0.8, respectively and are kept constant throughout the investigation. The resulting time- and spatially-averaged velocity and temperature wall functions from the new wall models match well with the law-of-the-wall experimental data at Re = 50,000. In order to study the effect of hot air impinging walls, jet impingement on a flat plate is also tested with the new wall models. The jet Reynolds number is equal to 21,000 and a fixed jet-to-plate spacing of H/D = 2.0. As predicted by the new wall models, the time-averaged skin friction coefficient agrees well with experimental data, while the computed Nusselt number agrees fairly well when r/D > 2.0. Additionally, the model is validated using experimental data from a Caterpillar engine operated with conventional diesel combustion. Sixteen different operating engine conditions are simulated. The majority of the predicted heat flux results from each thermocouple location follow similar trends when compared with experimental data. The magnitude of peak heat fluxes as predicted by the new wall models is in the range of typical measured values in diesel combustion, while most heat flux results from previous LES wall models are over-predicted. The new wall models generate more accurate predictions and agree better with experimental data.

  9. Parents as Role Models: Parental Behavior Affects Adolescents' Plans for Work Involvement

    Science.gov (United States)

    Wiese, Bettina S.; Freund, Alexandra M.

    2011-01-01

    This study (N = 520 high-school students) investigates the influence of parental work involvement on adolescents' own plans regarding their future work involvement. As expected, adolescents' perceptions of parental work behavior affected their plans for own work involvement. Same-sex parents served as main role models for the adolescents' own…

  10. Improving CASINO performance for models with large number of electrons

    Energy Technology Data Exchange (ETDEWEB)

    Anton, L; Alfe, D; Hood, R Q; Tanqueray, D

    2009-05-13

    Quantum Monte Carlo calculations have at their core algorithms based on statistical ensembles of multidimensional random walkers which are straightforward to use on parallel computers. Nevertheless some computations have reached the limit of the memory resources for models with more than 1000 electrons because of the need to store a large amount of electronic orbitals related data. Besides that, for systems with large number of electrons, it is interesting to study if the evolution of one configuration of random walkers can be done faster in parallel. We present a comparative study of two ways to solve these problems: (1) distributed orbital data done with MPI or Unix inter-process communication tools, (2) second level parallelism for configuration computation.

  11. Leukocyte deformability: finite element modeling of large viscoelastic deformation.

    Science.gov (United States)

    Dong, C; Skalak, R

    1992-09-21

    An axisymmetric deformation of a viscoelastic sphere bounded by a prestressed elastic thin shell in response to external pressure is studied by a finite element method. The research is motivated by the need for understanding the passive behavior of human leukocytes (white blood cells) and interpreting extensive experimental data in terms of the mechanical properties. The cell at rest is modeled as a sphere consisting of a cortical prestressed shell with incompressible Maxwell fluid interior. A large-strain deformation theory is developed based on the proposed model. General non-linear, large strain constitutive relations for the cortical shell are derived by neglecting the bending stiffness. A representation of the constitutive equations in the form of an integral of strain history for the incompressible Maxwell interior is used in the formulation of numerical scheme. A finite element program is developed, in which a sliding boundary condition is imposed on all contact surfaces. The mathematical model developed is applied to evaluate experimental data of pipette tests and observations of blood flow.

  12. Large animal models for vaccine development and testing.

    Science.gov (United States)

    Gerdts, Volker; Wilson, Heather L; Meurens, Francois; van Drunen Littel-van den Hurk, Sylvia; Wilson, Don; Walker, Stewart; Wheler, Colette; Townsend, Hugh; Potter, Andrew A

    2015-01-01

    The development of human vaccines continues to rely on the use of animals for research. Regulatory authorities require novel vaccine candidates to undergo preclinical assessment in animal models before being permitted to enter the clinical phase in human subjects. Substantial progress has been made in recent years in reducing and replacing the number of animals used for preclinical vaccine research through the use of bioinformatics and computational biology to design new vaccine candidates. However, the ultimate goal of a new vaccine is to instruct the immune system to elicit an effective immune response against the pathogen of interest, and no alternatives to live animal use currently exist for evaluation of this response. Studies identifying the mechanisms of immune protection; determining the optimal route and formulation of vaccines; establishing the duration and onset of immunity, as well as the safety and efficacy of new vaccines, must be performed in a living system. Importantly, no single animal model provides all the information required for advancing a new vaccine through the preclinical stage, and research over the last two decades has highlighted that large animals more accurately predict vaccine outcome in humans than do other models. Here we review the advantages and disadvantages of large animal models for human vaccine development and demonstrate that much of the success in bringing a new vaccine to market depends on choosing the most appropriate animal model for preclinical testing. © The Author 2015. Published by Oxford University Press on behalf of the Institute for Laboratory Animal Research. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  13. Large eddy simulation subgrid model for soot prediction

    Science.gov (United States)

    El-Asrag, Hossam Abd El-Raouf Mostafa

    Soot prediction in realistic systems is one of the most challenging problems in theoretical and applied combustion. Soot formation as a chemical process is very complicated and not fully understood. The major difficulty stems from the chemical complexity of the soot formation process as well as its strong coupling with the other thermochemical and fluid processes that occur simultaneously. Soot is a major byproduct of incomplete combustion, having a strong impact on the environment as well as the combustion efficiency. Therefore, innovative methods is needed to predict soot in realistic configurations in an accurate and yet computationally efficient way. In the current study, a new soot formation subgrid model is developed and reported here. The new model is designed to be used within the context of the Large Eddy Simulation (LES) framework, combined with Linear Eddy Mixing (LEM) as a subgrid combustion model. The final model can be applied equally to premixed and non-premixed flames over any required geometry and flow conditions in the free, the transition, and the continuum regimes. The soot dynamics is predicted using a Method of Moments approach with Lagrangian Interpolative Closure (MOMIC) for the fractional moments. Since no prior knowledge of the particles distribution is required, the model is generally applicable. The current model accounts for the basic soot transport phenomena as transport by molecular diffusion and Thermophoretic forces. The model is first validated against experimental results for non-sooting swirling non-premixed and partially premixed flames. Next, a set of canonical premixed sooting flames are simulated, where the effect of turbulence, binary diffusivity and C/O ratio on soot formation are studied. Finally, the model is validated against a non-premixed jet sooting flame. The effect of the flame structure on the different soot formation stages as well as the particle size distribution is described. Good results are predicted with

  14. Scale invariant behavior in a large N matrix model

    CERN Document Server

    Narayanan, Rajamani

    2016-01-01

    Eigenvalue distributions of properly regularized Wilson loop operators are used to study the transition from ultra-violet (UV) behavior to infra-red (IR) behavior in gauge theories coupled to matter that potentially have an IR fixed point (FP). We numerically demonstrate emergence of scale invariance in a matrix model that describes $SU(N)$ gauge theory coupled to two flavors of massless adjoint fermions in the large $N$ limit. The eigenvalue distribution of Wilson loops of varying sizes cannot be described by a universal lattice beta-function connecting the UV to the IR.

  15. Modeling skin effect in large magnetized iron detectors

    CERN Document Server

    Incurvati, M

    2003-01-01

    The experimental problem of the calibration of magnetic field in large iron detectors is discussed. Emphasis is laid on techniques based on ballistic measurements as the ones employed by MINOS or OPERA.In particular, we provide analytical formulas to model the behavior of the apparatus in the transient regime, keeping into account eddy current effects and the finite penetration velocity of the driving fields. These formulas ease substantially the design of the calibration apparatus.Results are compared with experimental data coming from a prototype of the OPERA spectrometer.

  16. Design and modelling of innovative machinery systems for large ships

    DEFF Research Database (Denmark)

    Larsen, Ulrik

    Eighty percent of the growing global merchandise trade is transported by sea. The shipping industry is required to reduce the pollution and increase the energy efficiency of ships in the near future. There is a relatively large potential for approaching these requirements by implementing waste heat...... parameters for marine WHR. Using this mentioned methodology, regression models are derived for the prediction of the maximum obtainable thermal efficiency of ORCs. A unique configuration of the Kalina cycle, the Split-cycle, is analysed to evaluate the fullest potential of the Kalina cycle for the purpose...

  17. Modeling of large-scale oxy-fuel combustion processes

    DEFF Research Database (Denmark)

    Yin, Chungen

    2012-01-01

    , among which radiative heat transfer under oxy-fuel conditions is one of the fundamental issues. This paper demonstrates the nongray-gas effects in modeling of large-scale oxy-fuel combustion processes. Oxy-fuel combustion of natural gas in a 609MW utility boiler is numerically studied, in which....... The simulation results show that the gray and non-gray calculations of the same oxy-fuel WSGGM make distinctly different predictions in the wall radiative heat transfer, incident radiative flux, radiative source, gas temperature and species profiles. In relative to the non-gray implementation, the gray...

  18. A Model for Predicting Thermomechanical Response of Large Space Structures.

    Science.gov (United States)

    1984-06-01

    Dr. Tony Amos (202)767-4937 u.DD FORM 1473, 83 APR EDITION OF I JAN 73 IS OBSOLETE. SECURITY CLASSIFICATION CF THIS PAGE .. ’o 1 v A MODEL FOR...SYMBOL Dr. Tony Amos (202)767-4937 SDD FORM 1473, 83 APR E c , TION OF 1 JAN 73 ,S OBSOLETE. SECLUHITY (CLASSI. ICATION Oi) THI PAGE -i LARGE SPACE...94] for predicting the buckling loads associated with general instability of beam-like lattice trusses. Bazant and Christensen [95] present a

  19. Resin infusion of large composite structures modeling and manufacturing process

    Energy Technology Data Exchange (ETDEWEB)

    Loos, A.C. [Michigan State Univ., Dept. of Mechanical Engineering, East Lansing, MI (United States)

    2006-07-01

    The resin infusion processes resin transfer molding (RTM), resin film infusion (RFI) and vacuum assisted resin transfer molding (VARTM) are cost effective techniques for the fabrication of complex shaped composite structures. The dry fibrous preform is placed in the mold, consolidated, resin impregnated and cured in a single step process. The fibrous performs are often constructed near net shape using highly automated textile processes such as knitting, weaving and braiding. In this paper, the infusion processes RTM, RFI and VARTM are discussed along with the advantages of each technique compared with traditional composite fabrication methods such as prepreg tape lay up and autoclave cure. The large number of processing variables and the complex material behavior during infiltration and cure make experimental optimization of the infusion processes costly and inefficient. Numerical models have been developed which can be used to simulate the resin infusion processes. The model formulation and solution procedures for the VARTM process are presented. A VARTM process simulation of a carbon fiber preform was presented to demonstrate the type of information that can be generated by the model and to compare the model predictions with experimental measurements. Overall, the predicted flow front positions, resin pressures and preform thicknesses agree well with the measured values. The results of the simulation show the potential cost and performance benefits that can be realized by using a simulation model as part of the development process. (au)

  20. Do land parameters matter in large-scale hydrological modelling?

    Science.gov (United States)

    Gudmundsson, Lukas; Seneviratne, Sonia I.

    2013-04-01

    Many of the most pending issues in large-scale hydrology are concerned with predicting hydrological variability at ungauged locations. However, current-generation hydrological and land surface models that are used for their estimation suffer from large uncertainties. These models rely on mathematical approximations of the physical system as well as on mapped values of land parameters (e.g. topography, soil types, land cover) to predict hydrological variables (e.g. evapotranspiration, soil moisture, stream flow) as a function of atmospheric forcing (e.g. precipitation, temperature, humidity). Despite considerable progress in recent years, it remains unclear whether better estimates of land parameters can improve predictions - or - if a refinement of model physics is necessary. To approach this question we suggest scrutinizing our perception of hydrological systems by confronting it with the radical assumption that hydrological variability at any location in space depends on past and present atmospheric forcing only, and not on location-specific land parameters. This so called "Constant Land Parameter Hypothesis (CLPH)" assumes that variables like runoff can be predicted without taking location specific factors such as topography or soil types into account. We demonstrate, using a modern statistical tool, that monthly runoff in Europe can be skilfully estimated using atmospheric forcing alone, without accounting for locally varying land parameters. The resulting runoff estimates are used to benchmark state-of-the-art process models. These are found to have inferior performance, despite their explicit process representation, which accounts for locally varying land parameters. This suggests that progress in the theory of hydrological systems is likely to yield larger improvements in model performance than more precise land parameter estimates. The results also question the current modelling paradigm that is dominated by the attempt to account for locally varying land

  1. Introducing an Intervention Model for Fostering Affective Involvement with Persons Who Are Congenitally Deafblind

    Science.gov (United States)

    Martens, Marga A. W.; Janssen, Marleen J.; Ruijssenaars, Wied A. J. J. M.; Riksen-Walraven, J. Marianne

    2014-01-01

    The article presented here introduces the Intervention Model for Affective Involvement (IMAI), which was designed to train staff members (for example, teachers, caregivers, support workers) to foster affective involvement during interaction and communication with persons who have congenital deaf-blindness. The model is theoretically underpinned,…

  2. Large-Signal DG-MOSFET Modelling for RFID Rectification

    Directory of Open Access Journals (Sweden)

    R. Rodríguez

    2016-01-01

    Full Text Available This paper analyses the undoped DG-MOSFETs capability for the operation of rectifiers for RFIDs and Wireless Power Transmission (WPT at microwave frequencies. For this purpose, a large-signal compact model has been developed and implemented in Verilog-A. The model has been numerically validated with a device simulator (Sentaurus. It is found that the number of stages to achieve the optimal rectifier performance is inferior to that required with conventional MOSFETs. In addition, the DC output voltage could be incremented with the use of appropriate mid-gap metals for the gate, as TiN. Minor impact of short channel effects (SCEs on rectification is also pointed out.

  3. Lattice Boltzmann Large Eddy Simulation Model of MHD

    CERN Document Server

    Flint, Christopher

    2016-01-01

    The work of Ansumali \\textit{et al.}\\cite{Ansumali} is extended to Two Dimensional Magnetohydrodynamic (MHD) turbulence in which energy is cascaded to small spatial scales and thus requires subgrid modeling. Applying large eddy simulation (LES) modeling of the macroscopic fluid equations results in the need to apply ad-hoc closure schemes. LES is applied to a suitable mesoscopic lattice Boltzmann representation from which one can recover the MHD equations in the long wavelength, long time scale Chapman-Enskog limit (i.e., the Knudsen limit). Thus on first performing filter width expansions on the lattice Boltzmann equations followed by the standard small Knudsen expansion on the filtered lattice Boltzmann system results in a closed set of MHD turbulence equations provided we enforce the physical constraint that the subgrid effects first enter the dynamics at the transport time scales. In particular, a multi-time relaxation collision operator is considered for the density distribution function and a single rel...

  4. Large N classical dynamics of holographic matrix models

    CERN Document Server

    Asplund, Curtis T; Dzienkowski, Eric

    2014-01-01

    Using a numerical simulation of the classical dynamics of the plane-wave and flat space matrix models of M-theory, we study the thermalization, equilibrium thermodynamics and fluctuations of these models as we vary the temperature and the size of the matrices, N. We present our numerical implementation in detail and several checks of its precision and consistency. We show evidence for thermalization by matching the time-averaged distributions of the matrix eigenvalues to the distributions of the appropriate Traceless Gaussian Unitary Ensemble of random matrices. We study the autocorrelations and power spectra for various fluctuating observables and observe evidence of the expected chaotic dynamics as well as a hydrodynamic type limit at large N, including near-equilibrium dissipation processes. These configurations are holographically dual to black holes in the dual string theory or M-theory and we discuss how our results could be related to the corresponding supergravity black hole solutions.

  5. Using Flume Experiments to Model Large Woody Debris Transport Dynamics

    Science.gov (United States)

    Braudrick, C. A.; Grant, G. E.

    2001-05-01

    In the last decade there has been increasing interest in quantifying the transport dynamics of large woody debris in a variety of stream types. We used flume experiments to test theoretical models of wood entrainment, transport, and deposition in streams. Because wood moves infrequently during high flows where direct measurement and observation can be difficult and dangerous. Flume experiments provide an excellent setting to study wood dynamics because channel types, flow, log size, and other parameters can be varied relatively easily and extensive data can be collected over a short time period. Our flume experiments verified theoretical model predictions that piece movement is dependent on the diameter of the log and its orientation in large rivers (where piece length is less than channel width). Piece length, often reported as the most important factor in determining piece movement in field studies, was not a factor in these simulated large channels. This is likely due to the importance of banks and vegetation on inhibiting log movement in the field, particularly for pieces longer than channel width. Logs are often at least partially lodged on the banks sometimes upstream of vegetation or other logs which anchors the piece, and increases the force required for entrainment. Rootwads also increased the flow depth required to move individual logs. By raising logs off the channel bed, rootwads decrease the buoyant and drag forces acting on the log. We also developed a theoretical model of wood transport and deposition based upon the ratios of the piece length to channel width, piece length to the radius of curvature of the channel, and piece diameter to water depth. In these experiments we noted that individual logs tend to move down the channel parallel to the channel margin, and deposited on the outside of bends, heads of shallow and exposed bars, and bar crossovers. Our theoretical model was not borne out by the experiments, likely because there were few potential

  6. The Importance of Computational Modeling of Large Pumping Stations

    Directory of Open Access Journals (Sweden)

    S. M. Bozh'eva

    2015-01-01

    Full Text Available The article presents main design and structure principles of pumping stations. It specifies basic requirements for the favorable hydraulic operation conditions of the pumping units. The article also describes the designing cases, when computational modeling is necessary to analyse activity of pumping station and provide its reliable operation. A specific example of the large pumping station with submersible pumps describes the process of computational modeling of its operation. As the object of simulation was selected the underground pumping station with a diameter of 26 m and a depth of 13 m, divided into two independent branches, equipped with 8 submersible pumps. The objective of this work was to evaluate the effectiveness of the design solution by CFD methods, to analyze the design of the inlet chamber, to identify possible difficulties with the operation of the facility. In details are described the structure of the considered pumping station and applied computational models of physical processes. The article gives the detailed formulation of the task of simulation and the methods of its solving and presents the initial and boundary conditions. It describes the basic operation modes of the pumping station. The obtained results were presented as the flow patterns for each operation mode with detailed explanations. Data obtained as a result of CFD, prove the correctness of the general design solutions of the project. The submersible pump operation at the minimum water level was verified, was confirmed a lack of vortex formation as well as were proposed measures to improve the operating conditions of the facility. In the inlet chamber there are shown the stagnant zones, requiring separate schedule of cleaning. The measure against floating debris and foam was proposed. It justifies the use of computational modeling (CFD for the verifying and adjusting of the projects of large pumping stations as a much more precise tool that takes into account

  7. Exploiting multi-scale parallelism for large scale numerical modelling of laser wakefield accelerators

    CERN Document Server

    Fonseca, Ricardo A; Fiúza, Frederico; Davidson, Asher; Tsung, Frank S; Mori, Warren B; Silva, Luís O

    2013-01-01

    A new generation of laser wakefield accelerators, supported by the extreme accelerating fields generated in the interaction of PW-Class lasers and underdense targets, promises the production of high quality electron beams in short distances for multiple applications. Achieving this goal will rely heavily on numerical modeling for further understanding of the underlying physics and identification of optimal regimes, but large scale modeling of these scenarios is computationally heavy and requires efficient use of state-of-the-art Petascale supercomputing systems. We discuss the main difficulties involved in running these simulations and the new developments implemented in the OSIRIS framework to address these issues, ranging from multi-dimensional dynamic load balancing and hybrid distributed / shared memory parallelism to the vectorization of the PIC algorithm. We present the results of the OASCR Joule Metric program on the issue of large scale modeling of LWFA, demonstrating speedups of over 1 order of magni...

  8. Aeroservoelastic model based active control for large civil aircraft

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A modeling and control approach for an advanced configured large civil aircraft with aeroservoelasticity via the LQG method and control allocation is presented.Mathematical models and implementation issues for the multi-input/multi-output(MIMO) aeroservoelastic system simulation developed for a flexible wing with multi control surfaces are described.A fuzzy logic based optimization approach is employed to solve the constrained control allocation problem via intelligently adjusting the components of output vector and find a proper vector in the attainable moment set(AMS) autonomously.The basic idea is to minimize the L2 norm of error between the desired moment and achievable moment using the designing freedom provided by redundantly allocated actuators and control surfaces.Considering the constraints of control surfaces,in order to obtain acceptable performance of aircraft such as stability and maneuverability,the fuzzy weights are updated by the learning algorithm,which makes the closed-loop system self-adaptation.Finally,an application example of flight control designing for the advanced civil aircraft is discussed as a demonstration.The studies we have performed showed that the advanced configured large civil aircraft has good performance with the proper designed control law designed via the proposed approach.The gust alleviation and flutter suppression are applied with the synergetic effects of elevator,ailerons,equivalent rudders and flaps.The results show good closed loop performance and meet the requirement of constraint of control surfaces.

  9. Modelling large-scale halo bias using the bispectrum

    CERN Document Server

    Pollack, Jennifer E; Porciani, Cristiano

    2011-01-01

    We study the relation between the halo and matter density fields -- commonly termed bias -- in the LCDM framework. In particular, we examine the local model of biasing at quadratic order in matter density. This model is characterized by parameters b_1 and b_2. Using an ensemble of N-body simulations, we apply several statistical methods to estimate the parameters. We measure halo and matter fluctuations smoothed on various scales and find that the parameters vary with smoothing scale. We argue that, for real-space measurements, owing to the mixing of wavemodes, no scale can be found for which the parameters are independent of smoothing. However, this is not the case in Fourier space. We measure halo power spectra and construct estimates for an effective large-scale bias. We measure the configuration dependence of the halo bispectra B_hhh and reduced bispectra Q_hhh for very large-scale k-space triangles. From this we constrain b_1 and b_2. Using the lowest-order perturbation theory, we find that for B_hhh the...

  10. Some cases of machining large-scale parts: Characterization and modelling of heavy turning, deep drilling and broaching

    Science.gov (United States)

    Haddag, B.; Nouari, M.; Moufki, A.

    2016-10-01

    Machining large-scale parts involves extreme loading at the cutting zone. This paper presents an overview of some cases of machining large-scale parts: heavy turning, deep drilling and broaching processes. It focuses on experimental characterization and modelling methods of these processes. Observed phenomena and/or measured cutting forces are reported. The paper also discusses the predictive ability of the proposed models to reproduce experimental data.

  11. Modelling large scale human activity in San Francisco

    Science.gov (United States)

    Gonzalez, Marta

    2010-03-01

    Diverse group of people with a wide variety of schedules, activities and travel needs compose our cities nowadays. This represents a big challenge for modeling travel behaviors in urban environments; those models are of crucial interest for a wide variety of applications such as traffic forecasting, spreading of viruses, or measuring human exposure to air pollutants. The traditional means to obtain knowledge about travel behavior is limited to surveys on travel journeys. The obtained information is based in questionnaires that are usually costly to implement and with intrinsic limitations to cover large number of individuals and some problems of reliability. Using mobile phone data, we explore the basic characteristics of a model of human travel: The distribution of agents is proportional to the population density of a given region, and each agent has a characteristic trajectory size contain information on frequency of visits to different locations. Additionally we use a complementary data set given by smart subway fare cards offering us information about the exact time of each passenger getting in or getting out of the subway station and the coordinates of it. This allows us to uncover the temporal aspects of the mobility. Since we have the actual time and place of individual's origin and destination we can understand the temporal patterns in each visited location with further details. Integrating two described data set we provide a dynamical model of human travels that incorporates different aspects observed empirically.

  12. Modeling Resource Utilization of a Large Data Acquisition System

    CERN Document Server

    Santos, Alejandro; The ATLAS collaboration

    2017-01-01

    The ATLAS 'Phase-II' upgrade, scheduled to start in 2024, will significantly change the requirements under which the data-acquisition system operates. The input data rate, currently fixed around 150 GB/s, is anticipated to reach 5 TB/s. In order to deal with the challenging conditions, and exploit the capabilities of newer technologies, a number of architectural changes are under consideration. Of particular interest is a new component, known as the Storage Handler, which will provide a large buffer area decoupling real-time data taking from event filtering. Dynamic operational models of the upgraded system can be used to identify the required resources and to select optimal techniques. In order to achieve a robust and dependable model, the current data-acquisition architecture has been used as a test case. This makes it possible to verify and calibrate the model against real operation data. Such a model can then be evolved toward the future ATLAS Phase-II architecture. In this paper we introduce the current ...

  13. Modelling Resource Utilization of a Large Data Acquisition System

    CERN Document Server

    Santos, Alejandro; The ATLAS collaboration

    2017-01-01

    The ATLAS 'Phase-II' upgrade, scheduled to start in 2024, will significantly change the requirements under which the data-acquisition system operates. The input data rate, currently fixed around 150 GB/s, is anticipated to reach 5 TB/s. In order to deal with the challenging conditions, and exploit the capabilities of newer technologies, a number of architectural changes are under consideration. Of particular interest is a new component, known as the Storage Handler, which will provide a large buffer area decoupling real-time data taking from event filtering. Dynamic operational models of the upgraded system can be used to identify the required resources and to select optimal techniques. In order to achieve a robust and dependable model, the current data-acquisition architecture has been used as a test case. This makes it possible to verify and calibrate the model against real operation data. Such a model can then be evolved toward the future ATLAS Phase-II architecture. In this paper we introduce the current ...

  14. AtMic60 Is Involved in Plant Mitochondria Lipid Trafficking and Is Part of a Large Complex.

    Science.gov (United States)

    Michaud, Morgane; Gros, Valérie; Tardif, Marianne; Brugière, Sabine; Ferro, Myriam; Prinz, William A; Toulmay, Alexandre; Mathur, Jaideep; Wozny, Michael; Falconet, Denis; Maréchal, Eric; Block, Maryse A; Jouhet, Juliette

    2016-03-07

    The mitochondrion is an organelle originating from an endosymbiotic event and playing a role in several fundamental processes such as energy production, metabolite syntheses, and programmed cell death. This organelle is delineated by two membranes whose synthesis requires an extensive exchange of phospholipids with other cellular organelles such as endoplasmic reticulum (ER) and vacuolar membranes in yeast. These transfers of phospholipids are thought to occur by a non-vesicular pathway at contact sites between two closely apposed membranes. In plants, little is known about the biogenesis of mitochondrial membranes. Contact sites between ER and mitochondria are suspected to play a similar role in phospholipid trafficking as in yeast, but this has never been demonstrated. In contrast, it has been shown that plastids are able to transfer lipids to mitochondria during phosphate starvation. However, the proteins involved in such transfer are still unknown. Here, we identified in Arabidopsis thaliana a large lipid-enriched complex called the mitochondrial transmembrane lipoprotein (MTL) complex. The MTL complex contains proteins located in the two mitochondrial membranes and conserved in all eukaryotic cells, such as the TOM complex and AtMic60, a component of the MICOS complex. We demonstrate that AtMic60 contributes to the export of phosphatidylethanolamine from mitochondria and the import of galactoglycerolipids from plastids during phosphate starvation. Furthermore, AtMic60 promotes lipid desorption from membranes, likely as an initial step for lipid transfer, and binds to Tom40, suggesting that AtMic60 could regulate the tethering between the inner and outer membranes of mitochondria.

  15. An overview of comparative modelling and resources dedicated to large-scale modelling of genome sequences.

    Science.gov (United States)

    Lam, Su Datt; Das, Sayoni; Sillitoe, Ian; Orengo, Christine

    2017-08-01

    Computational modelling of proteins has been a major catalyst in structural biology. Bioinformatics groups have exploited the repositories of known structures to predict high-quality structural models with high efficiency at low cost. This article provides an overview of comparative modelling, reviews recent developments and describes resources dedicated to large-scale comparative modelling of genome sequences. The value of subclustering protein domain superfamilies to guide the template-selection process is investigated. Some recent cases in which structural modelling has aided experimental work to determine very large macromolecular complexes are also cited.

  16. Improving large-scale groundwater models by considering fossil gradients

    Science.gov (United States)

    Schulz, Stephan; Walther, Marc; Michelsen, Nils; Rausch, Randolf; Dirks, Heiko; Al-Saud, Mohammed; Merz, Ralf; Kolditz, Olaf; Schüth, Christoph

    2017-05-01

    Due to limited availability of surface water, many arid to semi-arid countries rely on their groundwater resources. Despite the quasi-absence of present day replenishment, some of these groundwater bodies contain large amounts of water, which was recharged during pluvial periods of the Late Pleistocene to Early Holocene. These mostly fossil, non-renewable resources require different management schemes compared to those which are usually applied in renewable systems. Fossil groundwater is a finite resource and its withdrawal implies mining of aquifer storage reserves. Although they receive almost no recharge, some of them show notable hydraulic gradients and a flow towards their discharge areas, even without pumping. As a result, these systems have more discharge than recharge and hence are not in steady state, which makes their modelling, in particular the calibration, very challenging. In this study, we introduce a new calibration approach, composed of four steps: (i) estimating the fossil discharge component, (ii) determining the origin of fossil discharge, (iii) fitting the hydraulic conductivity with a pseudo steady-state model, and (iv) fitting the storage capacity with a transient model by reconstructing head drawdown induced by pumping activities. Finally, we test the relevance of our approach and evaluated the effect of considering or ignoring fossil gradients on aquifer parameterization for the Upper Mega Aquifer (UMA) on the Arabian Peninsula.

  17. Reconstruction of large-scale gene regulatory networks using Bayesian model averaging.

    Science.gov (United States)

    Kim, Haseong; Gelenbe, Erol

    2012-09-01

    Gene regulatory networks provide the systematic view of molecular interactions in a complex living system. However, constructing large-scale gene regulatory networks is one of the most challenging problems in systems biology. Also large burst sets of biological data require a proper integration technique for reliable gene regulatory network construction. Here we present a new reverse engineering approach based on Bayesian model averaging which attempts to combine all the appropriate models describing interactions among genes. This Bayesian approach with a prior based on the Gibbs distribution provides an efficient means to integrate multiple sources of biological data. In a simulation study with maximum of 2000 genes, our method shows better sensitivity than previous elastic-net and Gaussian graphical models, with a fixed specificity of 0.99. The study also shows that the proposed method outperforms the other standard methods for a DREAM dataset generated by nonlinear stochastic models. In brain tumor data analysis, three large-scale networks consisting of 4422 genes were built using the gene expression of non-tumor, low and high grade tumor mRNA expression samples, along with DNA-protein binding affinity information. We found that genes having a large variation of degree distribution among the three tumor networks are the ones that see most involved in regulatory and developmental processes, which possibly gives a novel insight concerning conventional differentially expressed gene analysis.

  18. The Oskarshamn model for public involvement in the siting of nuclear facilities

    Energy Technology Data Exchange (ETDEWEB)

    Aahagen, H. [Ahagen and Co (Sweden); CarIsson, Torsten [Mayor, Oskarshamn (Sweden); Hallberg, K. [Local Competence Building, Oskarshamn (Sweden); Andersson, Kjell [Karinta-Konsult, Taeby(Sweden)

    1999-12-01

    The Oskarshamn model has so far worked extremely well as a tool to achieve openness and public participation. The municipality involvement has been successful in several aspects, e.g.: It has been possible to influence the program, to a large extent, to meet certain municipality conditions and to ensure the local perspective. The local competence has increased to a considerable degree. The activities generated by the six working groups with a total of 40 members have generated a large number of contacts with various organisations, schools, mass media, individuals in the general public and interest groups. For the future, clarification of the disposal method and site selection criteria as well as the site selection process as such is crucial. The municipality has also emphasised the importance of SKB having shown the integration between site selection criteria, the feasibility study and the safety assessment. Furthermore, the programs for the encapsulation facility and the repository must be co-ordinated. For Oskarshamn it will be of utmost importance that the repository is well under way to be realised before the encapsulation facility can be built.

  19. Efficiently parallelized modeling of tightly focused, large bandwidth laser pulses

    Science.gov (United States)

    Dumont, Joey; Fillion-Gourdeau, François; Lefebvre, Catherine; Gagnon, Denis; MacLean, Steve

    2017-02-01

    The Stratton-Chu integral representation of electromagnetic fields is used to study the spatio-temporal properties of large bandwidth laser pulses focused by high numerical aperture mirrors. We review the formal aspects of the derivation of diffraction integrals from the Stratton-Chu representation and discuss the use of the Hadamard finite part in the derivation of the physical optics approximation. By analyzing the formulation we show that, for the specific case of a parabolic mirror, the integrands involved in the description of the reflected field near the focal spot do not possess the strong oscillations characteristic of diffraction integrals. Consequently, the integrals can be evaluated with simple and efficient quadrature methods rather than with specialized, more costly approaches. We report on the development of an efficiently parallelized algorithm that evaluates the Stratton-Chu diffraction integrals for incident fields of arbitrary temporal and spatial dependence. This method has the advantage that its input is the unfocused field coming from the laser chain, which is experimentally known with high accuracy. We use our method to show that the reflection of a linearly polarized Gaussian beam of femtosecond duration off a high numerical aperture parabolic mirror induces ellipticity in the dominant field components and generates strong longitudinal components. We also estimate that future high-power laser facilities may reach intensities of {10}24 {{W}} {{cm}}-2.

  20. Large eddy simulation on unstructured meshes using Lagrangian subgrid-scale model for complex turbulent flows

    Science.gov (United States)

    Tran, Steven; Sahni, Onkar; RPI Team

    2015-11-01

    Large eddy simulations (LES) provide high fidelity in which the large-scale turbulent structures are resolved while their interactions with the subgrid scales are modeled. In a Smagorinsky-based LES approach, the unresolved stresses are modeled using an eddy viscosity which in-turn involves a model parameter that is unknown a priori and varies in space and time for complex problems. Therefore, dynamic procedures are employed to determine this parameter where averaging is applied to make the procedure robust. When applicable, spatial averaging is applied across homogeneous directions. However, for complex flows the Lagrangian subgrid-scale model employing averaging over pathlines becomes attractive. In contrast to the dynamic Smagorinsky model, variational multiscale (VMS) models have also been developed for LES. In this study, we investigate dynamic mixed models for LES based on the combinations of the Lagrangian subgrid-scale model and the residual-based VMS (RBVMS) approach to study complex, inhomogeneous turbulent flows on unstructured meshes. Applications range from flow through a channel to flow over an airfoil at a moderate angle of attack. Experimental and DNS data are used to make comparisons.

  1. Simulating large-scale pedestrian movement using CA and event driven model: Methodology and case study

    Science.gov (United States)

    Li, Jun; Fu, Siyao; He, Haibo; Jia, Hongfei; Li, Yanzhong; Guo, Yi

    2015-11-01

    Large-scale regional evacuation is an important part of national security emergency response plan. Large commercial shopping area, as the typical service system, its emergency evacuation is one of the hot research topics. A systematic methodology based on Cellular Automata with the Dynamic Floor Field and event driven model has been proposed, and the methodology has been examined within context of a case study involving the evacuation within a commercial shopping mall. Pedestrians walking is based on Cellular Automata and event driven model. In this paper, the event driven model is adopted to simulate the pedestrian movement patterns, the simulation process is divided into normal situation and emergency evacuation. The model is composed of four layers: environment layer, customer layer, clerk layer and trajectory layer. For the simulation of movement route of pedestrians, the model takes into account purchase intention of customers and density of pedestrians. Based on evacuation model of Cellular Automata with Dynamic Floor Field and event driven model, we can reflect behavior characteristics of customers and clerks at the situations of normal and emergency evacuation. The distribution of individual evacuation time as a function of initial positions and the dynamics of the evacuation process is studied. Our results indicate that the evacuation model using the combination of Cellular Automata with Dynamic Floor Field and event driven scheduling can be used to simulate the evacuation of pedestrian flows in indoor areas with complicated surroundings and to investigate the layout of shopping mall.

  2. The unified minimal supersymmetric model with large Yukawa couplings

    CERN Document Server

    Rattazzi, Riccardo

    1996-01-01

    The consequences of assuming the third-generation Yukawa couplings are all large and comparable are studied in the context of the minimal supersymmetric extension of the standard model. General aspects of the RG evolution of the parameters, theoretical constraints needed to ensure proper electroweak symmetry breaking, and experimental and cosmological bounds on low-energy parameters are presented. We also present complete and exact semi-analytic solutions to the 1-loop RG equations. Focusing on SU(5) or SO(10) unification, we analyze the relationship between the top and bottom masses and the superspectrum, and the phenomenological implications of the GUT conditions on scalar masses. Future experimental measurements of the superspectrum and of the strong coupling will distinguish between various GUT-scale scenarios. And if present experimental knowledge is to be accounted for most naturally, a particular set of predictions is singled out.

  3. Soil carbon management in large-scale Earth system modelling

    DEFF Research Database (Denmark)

    Olin, S.; Lindeskog, M.; Pugh, T. A. M.

    2015-01-01

    .5. Our results show that the potential for carbon sequestration due to typical cropland management practices such as no-till management and cover crops proposed in previous studies is not realised, globally or over larger climatic regions. Our results highlight important considerations to be made when......Croplands are vital ecosystems for human well-being and provide important ecosystem services such as crop yields, retention of nitrogen and carbon storage. On large (regional to global)-scale levels, assessment of how these different services will vary in space and time, especially in response...... to cropland management, are scarce. We explore cropland management alternatives and the effect these can have on future C and N pools and fluxes using the land-use-enabled dynamic vegetation model LPJ-GUESS (Lund–Potsdam–Jena General Ecosystem Simulator). Simulated crop production, cropland carbon storage...

  4. A stochastic large deformation model for computational anatomy

    DEFF Research Database (Denmark)

    Arnaudon, Alexis; Holm, Darryl D.; Pai, Akshay Sadananda Uppinakudru

    2017-01-01

    In the study of shapes of human organs using computational anatomy, variations are found to arise from inter-subject anatomical differences, disease-specific effects, and measurement noise. This paper introduces a stochastic model for incorporating random variations into the Large Deformation...... Diffeomorphic Metric Mapping (LDDMM) framework. By accounting for randomness in a particular setup which is crafted to fit the geometrical properties of LDDMM, we formulate the template estimation problem for landmarks with noise and give two methods for efficiently estimating the parameters of the noise fields...... from a prescribed data set. One method directly approximates the time evolution of the variance of each landmark by a finite set of differential equations, and the other is based on an Expectation-Maximisation algorithm. In the second method, the evaluation of the data likelihood is achieved without...

  5. Large geospatial images discovery: metadata model and technological framework

    Directory of Open Access Journals (Sweden)

    Lukáš Brůha

    2015-12-01

    Full Text Available The advancements in geospatial web technology triggered efforts for disclosure of valuable resources of historical collections. This paper focuses on the role of spatial data infrastructures (SDI in such efforts. The work describes the interplay between SDI technologies and potential use cases in libraries such as cartographic heritage. The metadata model is introduced to link up the sources from these two distinct fields. To enhance the data search capabilities, the work focuses on the representation of the content-based metadata of raster images, which is the crucial prerequisite to target the search in a more effective way. The architecture of the prototype system for automatic raster data processing, storage, analysis and distribution is introduced. The architecture responds to the characteristics of input datasets, namely to the continuous flow of very large raster data and related metadata. Proposed solutions are illustrated on the case study of cartometric analysis of digitised early maps and related metadata encoding.

  6. Computational modeling of single particle scattering over large distances

    Science.gov (United States)

    Rapp, Rebecca; Plumley, Rajan; McCracken, Michael

    2016-09-01

    We present a Monte Carlo simulation of the propagation of a single particle through a large three-dimensional volume under the influence of individual scattering events. In such systems, short paths can be quickly and accurately simulated using random walks defined by individual scattering parameters, but the simulation time greatly increases as the size of the space grows. We present a method for reducing the overall simulation time by restricting the simulation to a cube of unit length; each `cell' is characterized by a set of parameters which dictate the distributions of allowable step lengths and polar scattering angles. We model propagation over large distances by constructing a lattice of cells with physical parameters that depend on position, such that the full set would represent a space within the entire volume available to the particle. With these, we propose the use of Markov chains to determine a probable path for the particle, thereby removing the need to simulate every step in the particle's path. For a single particle with constant velocity, we can use the step statistics to determine the travel time of the particle. We investigate the effect of scattering parameters such as average step distance and possible scattering angles on the probabilities of a cell.

  7. Large scale solar district heating. Evaluation, modelling and designing

    Energy Technology Data Exchange (ETDEWEB)

    Heller, A.

    2000-07-01

    The main objective of the research was to evaluate large-scale solar heating connected to district heating (CSDHP), to build up a simulation tool and to demonstrate the application of the tool for design studies and on a local energy planning case. The evaluation of the central solar heating technology is based on measurements on the case plant in Marstal, Denmark, and on published and unpublished data for other, mainly Danish, CSDHP plants. Evaluations on the thermal, economical and environmental performances are reported, based on the experiences from the last decade. The measurements from the Marstal case are analysed, experiences extracted and minor improvements to the plant design proposed. For the detailed designing and energy planning of CSDHPs, a computer simulation model is developed and validated on the measurements from the Marstal case. The final model is then generalised to a 'generic' model for CSDHPs in general. The meteorological reference data, Danish Reference Year, is applied to find the mean performance for the plant designs. To find the expectable variety of the thermal performance of such plants, a method is proposed where data from a year with poor solar irradiation and a year with strong solar irradiation are applied. Equipped with a simulation tool design studies are carried out spreading from parameter analysis over energy planning for a new settlement to a proposal for the combination of plane solar collectors with high performance solar collectors, exemplified by a trough solar collector. The methodology of utilising computer simulation proved to be a cheap and relevant tool in the design of future solar heating plants. The thesis also exposed the demand for developing computer models for the more advanced solar collector designs and especially for the control operation of CSHPs. In the final chapter the CSHP technology is put into perspective with respect to other possible technologies to find the relevance of the application

  8. Mathematical modeling of local perfusion in large distensible microvascular networks

    Science.gov (United States)

    Causin, Paola; Malgaroli, Francesca

    2017-08-01

    Microvessels -blood vessels with diameter less than 200 microns- form large, intricate networks organized into arterioles, capillaries and venules. In these networks, the distribution of flow and pressure drop is a highly interlaced function of single vessel resistances and mutual vessel interactions. In this paper we propose a mathematical and computational model to study the behavior of microcirculatory networks subjected to different conditions. The network geometry is composed of a graph of connected straight cylinders, each one representing a vessel. The blood flow and pressure drop across the single vessel, further split into smaller elements, are related through a generalized Ohm's law featuring a conductivity parameter, function of the vessel cross section area and geometry, which undergo deformations under pressure loads. The membrane theory is used to describe the deformation of vessel lumina, tailored to the structure of thick-walled arterioles and thin-walled venules. In addition, since venules can possibly experience negative transmural pressures, a buckling model is also included to represent vessel collapse. The complete model including arterioles, capillaries and venules represents a nonlinear system of PDEs, which is approached numerically by finite element discretization and linearization techniques. We use the model to simulate flow in the microcirculation of the human eye retina, a terminal system with a single inlet and outlet. After a phase of validation against experimental measurements, we simulate the network response to different interstitial pressure values. Such a study is carried out both for global and localized variations of the interstitial pressure. In both cases, significant redistributions of the blood flow in the network arise, highlighting the importance of considering the single vessel behavior along with its position and connectivity in the network.

  9. Effects of deceptive packaging and product involvement on purchase intention: an elaboration likelihood model perspective.

    Science.gov (United States)

    Lammers, H B

    2000-04-01

    From an Elaboration Likelihood Model perspective, it was hypothesized that postexposure awareness of deceptive packaging claims would have a greater negative effect on scores for purchase intention by consumers lowly involved rather than highly involved with a product (n = 40). Undergraduates who were classified as either highly or lowly (ns = 20 and 20) involved with M&Ms examined either a deceptive or non-deceptive package design for M&Ms candy and were subsequently informed of the deception employed in the packaging before finally rating their intention to purchase. As anticipated, highly deceived subjects who were low in involvement rated intention to purchase lower than their highly involved peers. Overall, the results attest to the robustness of the model and suggest that the model has implications beyond advertising effects and into packaging effects.

  10. Multi-Resolution Modeling of Large Scale Scientific Simulation Data

    Energy Technology Data Exchange (ETDEWEB)

    Baldwin, C; Abdulla, G; Critchlow, T

    2003-01-31

    This paper discusses using the wavelets modeling technique as a mechanism for querying large-scale spatio-temporal scientific simulation data. Wavelets have been used successfully in time series analysis and in answering surprise and trend queries. Our approach however is driven by the need for compression, which is necessary for viable throughput given the size of the targeted data, along with the end user requirements from the discovery process. Our users would like to run fast queries to check the validity of the simulation algorithms used. In some cases users are welling to accept approximate results if the answer comes back within a reasonable time. In other cases they might want to identify a certain phenomena and track it over time. We face a unique problem because of the data set sizes. It may take months to generate one set of the targeted data; because of its shear size, the data cannot be stored on disk for long and thus needs to be analyzed immediately before it is sent to tape. We integrated wavelets within AQSIM, a system that we are developing to support exploration and analyses of tera-scale size data sets. We will discuss the way we utilized wavelets decomposition in our domain to facilitate compression and in answering a specific class of queries that is harder to answer with any other modeling technique. We will also discuss some of the shortcomings of our implementation and how to address them.

  11. EXO-ZODI MODELING FOR THE LARGE BINOCULAR TELESCOPE INTERFEROMETER

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, Grant M.; Wyatt, Mark C.; Panić, Olja; Shannon, Andrew [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Bailey, Vanessa; Defrère, Denis; Hinz, Philip M.; Rieke, George H.; Skemer, Andrew J.; Su, Katherine Y. L. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Bryden, Geoffrey; Mennesson, Bertrand; Morales, Farisa; Serabyn, Eugene [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Danchi, William C.; Roberge, Aki; Stapelfeldt, Karl R. [NASA Goddard Space Flight Center, Exoplanets and Stellar Astrophysics, Code 667, Greenbelt, MD 20771 (United States); Haniff, Chris [Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Lebreton, Jérémy [Infrared Processing and Analysis Center, MS 100-22, California Institute of Technology, 770 South Wilson Avenue, Pasadena, CA 91125 (United States); Millan-Gabet, Rafael [NASA Exoplanet Science Institute, California Institute of Technology, 770 South Wilson Avenue, Pasadena, CA 91125 (United States); and others

    2015-02-01

    Habitable zone dust levels are a key unknown that must be understood to ensure the success of future space missions to image Earth analogs around nearby stars. Current detection limits are several orders of magnitude above the level of the solar system's zodiacal cloud, so characterization of the brightness distribution of exo-zodi down to much fainter levels is needed. To this end, the Large Binocular Telescope Interferometer (LBTI) will detect thermal emission from habitable zone exo-zodi a few times brighter than solar system levels. Here we present a modeling framework for interpreting LBTI observations, which yields dust levels from detections and upper limits that are then converted into predictions and upper limits for the scattered light surface brightness. We apply this model to the HOSTS survey sample of nearby stars; assuming a null depth uncertainty of 10{sup –4} the LBTI will be sensitive to dust a few times above the solar system level around Sun-like stars, and to even lower dust levels for more massive stars.

  12. An Overview of Westinghouse Realistic Large Break LOCA Evaluation Model

    Directory of Open Access Journals (Sweden)

    Cesare Frepoli

    2008-01-01

    Full Text Available Since the 1988 amendment of the 10 CFR 50.46 rule in 1988, Westinghouse has been developing and applying realistic or best-estimate methods to perform LOCA safety analyses. A realistic analysis requires the execution of various realistic LOCA transient simulations where the effect of both model and input uncertainties are ranged and propagated throughout the transients. The outcome is typically a range of results with associated probabilities. The thermal/hydraulic code is the engine of the methodology but a procedure is developed to assess the code and determine its biases and uncertainties. In addition, inputs to the simulation are also affected by uncertainty and these uncertainties are incorporated into the process. Several approaches have been proposed and applied in the industry in the framework of best-estimate methods. Most of the implementations, including Westinghouse, follow the Code Scaling, Applicability and Uncertainty (CSAU methodology. Westinghouse methodology is based on the use of the WCOBRA/TRAC thermal-hydraulic code. The paper starts with an overview of the regulations and its interpretation in the context of realistic analysis. The CSAU roadmap is reviewed in the context of its implementation in the Westinghouse evaluation model. An overview of the code (WCOBRA/TRAC and methodology is provided. Finally, the recent evolution to nonparametric statistics in the current edition of the W methodology is discussed. Sample results of a typical large break LOCA analysis for a PWR are provided.

  13. An ODE for an overloaded X model involving a stochastic averaging principle

    Directory of Open Access Journals (Sweden)

    Ward Whitt

    2011-01-01

    Full Text Available We study an ordinary differential equation (ODE arising as the many-server heavy-traffic fluid limit of a sequence of overloaded Markovian queueing models with two customer classes and two service pools. The system, known as the X model in the call-center literature, operates under the fixed-queue-ratio-with-thresholds (FQR-T control, which we proposed in a recent paper as a way for one service system to help another in face of an unanticipated overload. Each pool serves only its own class until a threshold is exceeded; then one-way sharing is activated with all customer-server assignments then driving the two queues toward a fixed ratio. For large systems, that fixed ratio is achieved approximately. The ODE describes system performance during an overload. The control is driven by a queue-difference stochastic process, which operates in a faster time scale than the queueing processes themselves, thus achieving a time-dependent steady state instantaneously in the limit. As a result, for the ODE, the driving process is replaced by its long-run average behavior at each instant of time; i.e., the ODE involves a heavy-traffic averaging principle (AP.

  14. Composite ALK-negative anaplastic large cell lymphoma and small lymphocytic lymphoma involving the right inguinal lymph node.

    Science.gov (United States)

    Persad, Paul; Pang, Changlee S

    2014-02-01

    Anaplastic large cell lymphoma and small lymphocytic lymphoma are two lymphoid malignancies with completely distinct morphologies and natural histories. We present a rare case of composite anaplastic large cell lymphoma and small lymphocytic lymphoma in an inguinal lymph node of an otherwise healthy 47-year-old male patient. Immunohistochemical and molecular studies identified the two populations clearly. Their separation is imperative as anaplastic large cell lymphoma can be an aggressive neoplasm and easily overlooked in cases of small lymphocytic lymphoma with a small population of anaplastic large cell lymphoma cells.

  15. Analysis and Modeling of Pedestrian Walking Behaviors Involving Individuals with Disabilities

    OpenAIRE

    Sharifi, Mohammad Sadra

    2016-01-01

    The objective of this dissertation was to study walking behaviors of pedestrian groups involving individuals with disabilities. To this end, large scale controlled walking experiments were conducted at Utah State University (USU) to examine walking behaviors in various walking facility types, such as passageway, right angle, oblique angle, queuing area, bottleneck, and stairs. Walking experiments were conducted over four days involving participants with and without disabilities. Automated vid...

  16. Multi-Resolution Modeling of Large Scale Scientific Simulation Data

    Energy Technology Data Exchange (ETDEWEB)

    Baldwin, C; Abdulla, G; Critchlow, T

    2002-02-25

    Data produced by large scale scientific simulations, experiments, and observations can easily reach tera-bytes in size. The ability to examine data-sets of this magnitude, even in moderate detail, is problematic at best. Generally this scientific data consists of multivariate field quantities with complex inter-variable correlations and spatial-temporal structure. To provide scientists and engineers with the ability to explore and analyze such data sets we are using a twofold approach. First, we model the data with the objective of creating a compressed yet manageable representation. Second, with that compressed representation, we provide the user with the ability to query the resulting approximation to obtain approximate yet sufficient answers; a process called adhoc querying. This paper is concerned with a wavelet modeling technique that seeks to capture the important physical characteristics of the target scientific data. Our approach is driven by the compression, which is necessary for viable throughput, along with the end user requirements from the discovery process. Our work contrasts existing research which applies wavelets to range querying, change detection, and clustering problems by working directly with a decomposition of the data. The difference in this procedures is due primarily to the nature of the data and the requirements of the scientists and engineers. Our approach directly uses the wavelet coefficients of the data to compress as well as query. We will provide some background on the problem, describe how the wavelet decomposition is used to facilitate data compression and how queries are posed on the resulting compressed model. Results of this process will be shown for several problems of interest and we will end with some observations and conclusions about this research.

  17. Multi-Resolution Modeling of Large Scale Scientific Simulation Data

    Energy Technology Data Exchange (ETDEWEB)

    Baldwin, C; Abdulla, G; Critchlow, T

    2002-02-25

    Data produced by large scale scientific simulations, experiments, and observations can easily reach tera-bytes in size. The ability to examine data-sets of this magnitude, even in moderate detail, is problematic at best. Generally this scientific data consists of multivariate field quantities with complex inter-variable correlations and spatial-temporal structure. To provide scientists and engineers with the ability to explore and analyze such data sets we are using a twofold approach. First, we model the data with the objective of creating a compressed yet manageable representation. Second, with that compressed representation, we provide the user with the ability to query the resulting approximation to obtain approximate yet sufficient answers; a process called adhoc querying. This paper is concerned with a wavelet modeling technique that seeks to capture the important physical characteristics of the target scientific data. Our approach is driven by the compression, which is necessary for viable throughput, along with the end user requirements from the discovery process. Our work contrasts existing research which applies wavelets to range querying, change detection, and clustering problems by working directly with a decomposition of the data. The difference in this procedures is due primarily to the nature of the data and the requirements of the scientists and engineers. Our approach directly uses the wavelet coefficients of the data to compress as well as query. We will provide some background on the problem, describe how the wavelet decomposition is used to facilitate data compression and how queries are posed on the resulting compressed model. Results of this process will be shown for several problems of interest and we will end with some observations and conclusions about this research.

  18. Modeling the Relations among Parental Involvement, School Engagement and Academic Performance of High School Students

    Science.gov (United States)

    Al-Alwan, Ahmed F.

    2014-01-01

    The author proposed a model to explain how parental involvement and school engagement related to academic performance. Participants were (671) 9th and 10th graders students who completed two scales of "parental involvement" and "school engagement" in their regular classrooms. Results of the path analysis suggested that the…

  19. A cooperative strategy for parameter estimation in large scale systems biology models

    Directory of Open Access Journals (Sweden)

    Villaverde Alejandro F

    2012-06-01

    Full Text Available Abstract Background Mathematical models play a key role in systems biology: they summarize the currently available knowledge in a way that allows to make experimentally verifiable predictions. Model calibration consists of finding the parameters that give the best fit to a set of experimental data, which entails minimizing a cost function that measures the goodness of this fit. Most mathematical models in systems biology present three characteristics which make this problem very difficult to solve: they are highly non-linear, they have a large number of parameters to be estimated, and the information content of the available experimental data is frequently scarce. Hence, there is a need for global optimization methods capable of solving this problem efficiently. Results A new approach for parameter estimation of large scale models, called Cooperative Enhanced Scatter Search (CeSS, is presented. Its key feature is the cooperation between different programs (“threads” that run in parallel in different processors. Each thread implements a state of the art metaheuristic, the enhanced Scatter Search algorithm (eSS. Cooperation, meaning information sharing between threads, modifies the systemic properties of the algorithm and allows to speed up performance. Two parameter estimation problems involving models related with the central carbon metabolism of E. coli which include different regulatory levels (metabolic and transcriptional are used as case studies. The performance and capabilities of the method are also evaluated using benchmark problems of large-scale global optimization, with excellent results. Conclusions The cooperative CeSS strategy is a general purpose technique that can be applied to any model calibration problem. Its capability has been demonstrated by calibrating two large-scale models of different characteristics, improving the performance of previously existing methods in both cases. The cooperative metaheuristic presented here

  20. FDG PET/CT for the detection of bone marrow involvement in diffuse large B-cell lymphoma: systematic review and meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Hugo J.A.; Kwee, Thomas C.; Keizer, Bart de; Nievelstein, Rutger A.J. [University Medical Center Utrecht, Department of Radiology and Nuclear Medicine, Utrecht (Netherlands); Fijnheer, Rob [Meander Medical Center, Department of Hematology, Amersfoort (Netherlands); Klerk, John M.H. de [Meander Medical Center, Department of Nuclear Medicine, Amersfoort (Netherlands)

    2014-03-15

    To systematically review and meta-analyse published data on the diagnostic performance of {sup 18}F-FDG PET/CT in detecting bone marrow involvement in patients with newly diagnosed diffuse large B-cell lymphoma (DLBCL). PubMed/MEDLINE and Embase were systematically searched for relevant studies. The methodological quality of each study was assessed. Sensitivities and specificities of FDG PET/CT in individual studies were calculated and meta-analysed with a random effects model. A summary receiver operating characteristic curve (sROC) was constructed with the Moses-Shapiro-Littenberg method. Weighted summary proportions of discrepancies between the FDG PET/CT and (blind) bone marrow biopsy (BMB) results among all patients were calculated. Seven studies, with a total of 654 patients with newly diagnosed DLBCL, were included. Overall, the quality of the included studies was moderate. The sensitivity and specificity of FDG PET/CT for detecting bone marrow involvement ranged from 70.8 % to 95.8 % and from 99.0 % to 100 %, with pooled estimates of 88.7 % (95 % confidence interval, CI, 82.5 - 93.3 %) and 99.8 % (95 % CI 98.8 - 100 %), respectively. The area under the sROC curve was 0.9983. The weighted summary proportion of FDG PET/CT-negative patients with positive BMB findings among all patients was 3.1 % (95 % CI 1.8 - 5.0 %) and the weighted summary proportion of FDG PET/CT-positive patients with negative BMB findings among all patients was 12.5 % (95 % CI 8.4 - 17.3 %). FDG PET/CT is accurate and complementary to BMB for detecting bone marrow involvement in patients with newly diagnosed DLBCL. A negative FDG PET/CT scan cannot rule out the presence of bone marrow involvement, but positive FDG PET/CT findings obviate the need for BMB for the detection of bone marrow involvement in these patients. (orig.)

  1. Applying the Plan-Do-Study-Act (PDSA) approach to a large pragmatic study involving safety net clinics.

    Science.gov (United States)

    Coury, Jennifer; Schneider, Jennifer L; Rivelli, Jennifer S; Petrik, Amanda F; Seibel, Evelyn; D'Agostini, Brieshon; Taplin, Stephen H; Green, Beverly B; Coronado, Gloria D

    2017-06-19

    The Plan-Do-Study-Act (PDSA) cycle is a commonly used improvement process in health care settings, although its documented use in pragmatic clinical research is rare. A recent pragmatic clinical research study, called the Strategies and Opportunities to STOP Colon Cancer in Priority Populations (STOP CRC), used this process to optimize the research implementation of an automated colon cancer screening outreach program in intervention clinics. We describe the process of using this PDSA approach, the selection of PDSA topics by clinic leaders, and project leaders' reactions to using PDSA in pragmatic research. STOP CRC is a cluster-randomized pragmatic study that aims to test the effectiveness of a direct-mail fecal immunochemical testing (FIT) program involving eight Federally Qualified Health Centers in Oregon and California. We and a practice improvement specialist trained in the PDSA process delivered structured presentations to leaders of these centers; the presentations addressed how to apply the PDSA process to improve implementation of a mailed outreach program offering colorectal cancer screening through FIT tests. Center leaders submitted PDSA plans and delivered reports via webinar at quarterly meetings of the project's advisory board. Project staff conducted one-on-one, 45-min interviews with project leads from each health center to assess the reaction to and value of the PDSA process in supporting the implementation of STOP CRC. Clinic-selected PDSA activities included refining the intervention staffing model, improving outreach materials, and changing workflow steps. Common benefits of using PDSA cycles in pragmatic research were that it provided a structure for staff to focus on improving the program and it allowed staff to test the change they wanted to see. A commonly reported challenge was measuring the success of the PDSA process with the available electronic medical record tools. Understanding how the PDSA process can be applied to pragmatic

  2. Uterine, but not ovarian, female reproductive organ involvement at presentation by diffuse large B-cell lymphoma is associated with poor outcomes and a high frequency of secondary CNS involvement

    DEFF Research Database (Denmark)

    El-Galaly, Tarec Christoffer; Cheah, Chan Y; Hutchings, Martin

    2016-01-01

    Involvement of the internal female reproductive organs by diffuse large B-cell lymphoma (DLBCL) is uncommon, and there are sparse data describing the outcomes of such cases. In total, 678 female patients with DLBCL staged with positron emission tomography/computed tomography and treated with ritu...

  3. A logistics model for large space power systems

    Science.gov (United States)

    Koelle, H. H.

    Space Power Systems (SPS) have to overcome two hurdles: (1) to find an attractive design, manufacturing and assembly concept and (2) to have available a space transportation system that can provide economical logistic support during the construction and operational phases. An initial system feasibility study, some five years ago, was based on a reference system that used terrestrial resources only and was based partially on electric propulsion systems. The conclusion was: it is feasible but not yet economically competitive with other options. This study is based on terrestrial and extraterrestrial resources and on chemical (LH 2/LOX) propulsion systems. These engines are available from the Space Shuttle production line and require small changes only. Other so-called advanced propulsion systems investigated did not prove economically superior if lunar LOX is available! We assume that a Shuttle derived Heavy Lift Launch Vehicle (HLLV) will become available around the turn of the century and that this will be used to establish a research base on the lunar surface. This lunar base has the potential to grow into a lunar factory producing LOX and construction materials for supporting among other projects also the construction of space power systems in geostationary orbit. A model was developed to simulate the logistics support of such an operation for a 50-year life cycle. After 50 years 111 SPS units with 5 GW each and an availability of 90% will produce 100 × 5 = 500 GW. The model comprises 60 equations and requires 29 assumptions of the parameter involved. 60-state variables calculated with the 60 equations mentioned above are given on an annual basis and as averages for the 50-year life cycle. Recycling of defective parts in geostationary orbit is one of the features of the model. The state-of-the-art with respect to SPS technology is introduced as a variable Mg mass/MW electric power delivered. If the space manufacturing facility, a maintenance and repair facility

  4. Uterine, but not ovarian, female reproductive organ involvement at presentation by diffuse large B-cell lymphoma is associated with poor outcomes and a high frequency of secondary CNS involvement.

    Science.gov (United States)

    El-Galaly, Tarec Christoffer; Cheah, Chan Y; Hutchings, Martin; Mikhaeel, Nabegh George; Savage, Kerry J; Sehn, Laurie H; Barrington, Sally; Hansen, Jakob W; Poulsen, Mette Ø; Smith, Daniel; Rady, Kirsty; Mylam, Karen J; Larsen, Thomas S; Holmberg, Staffan; Juul, Maja B; Cordua, Sabrina; Clausen, Michael R; Jensen, Kristina B; Bøgsted, Martin; Johnsen, Hans E; Seymour, John F; Connors, Joseph M; Brown, Peter D N; Villa, Diego

    2016-12-01

    Involvement of the internal female reproductive organs by diffuse large B-cell lymphoma (DLBCL) is uncommon, and there are sparse data describing the outcomes of such cases. In total, 678 female patients with DLBCL staged with positron emission tomography/computed tomography and treated with rituximab-containing chemotherapy were identified from databases in Denmark, Great Britain, Australia, and Canada. Overall, 27/678 (4%) had internal reproductive organ involvement: uterus (n = 14), ovaries (n = 10) or both (n = 3). In multivariate analysis, women with uterine DLBCL experienced inferior progression-free survival and overall survival compared to those without reproductive organ involvement, whereas ovarian DLBCL was not predictive of outcome. Secondary central nervous system (CNS) involvement (SCNS) occurred in 7/17 (41%) women with uterine DLBCL (two patients with concomitant ovarian DLBCL) and 0/10 women with ovarian DLBCL without concomitant uterine involvement. In multivariate analysis adjusted for other risk factors for SCNS, uterine involvement by DLBCL remained strongly associated with SCNS (Hazard ratio 14·13, 95% confidence interval 5·09-39·25, P involvement of the uterus by DLBCL appears to be associated with a high risk of SCNS, those patients should be considered for CNS staging and prophylaxis. However, more studies are needed to determine whether the increased risk of secondary CNS involvement also applies to women with localized reproductive organ DLBCL.

  5. Progress and Current Challenges in Modeling Large RNAs.

    Science.gov (United States)

    Somarowthu, Srinivas

    2016-02-27

    Recent breakthroughs in next-generation sequencing technologies have led to the discovery of several classes of non-coding RNAs (ncRNAs). It is now apparent that RNA molecules are not only just carriers of genetic information but also key players in many cellular processes. While there has been a rapid increase in the number of ncRNA sequences deposited in various databases over the past decade, the biological functions of these ncRNAs are largely not well understood. Similar to proteins, RNA molecules carry out a function by forming specific three-dimensional structures. Understanding the function of a particular RNA therefore requires a detailed knowledge of its structure. However, determining experimental structures of RNA is extremely challenging. In fact, RNA-only structures represent just 1% of the total structures deposited in the PDB. Thus, computational methods that predict three-dimensional RNA structures are in high demand. Computational models can provide valuable insights into structure-function relationships in ncRNAs and can aid in the development of functional hypotheses and experimental designs. In recent years, a set of diverse RNA structure prediction tools have become available, which differ in computational time, input data and accuracy. This review discusses the recent progress and challenges in RNA structure prediction methods.

  6. Dynamic Model Averaging in Large Model Spaces Using Dynamic Occam’s Window*

    Science.gov (United States)

    Onorante, Luca; Raftery, Adrian E.

    2015-01-01

    Bayesian model averaging has become a widely used approach to accounting for uncertainty about the structural form of the model generating the data. When data arrive sequentially and the generating model can change over time, Dynamic Model Averaging (DMA) extends model averaging to deal with this situation. Often in macroeconomics, however, many candidate explanatory variables are available and the number of possible models becomes too large for DMA to be applied in its original form. We propose a new method for this situation which allows us to perform DMA without considering the whole model space, but using a subset of models and dynamically optimizing the choice of models at each point in time. This yields a dynamic form of Occam’s window. We evaluate the method in the context of the problem of nowcasting GDP in the Euro area. We find that its forecasting performance compares well with that of other methods. PMID:26917859

  7. SEMICONDUCTOR DEVICES MEXTRAM model based SiGe HBT large-signal modeling

    Science.gov (United States)

    Bo, Han; Shoulin, Li; Jiali, Cheng; Qiuyan, Yin; Jianjun, Gao

    2010-10-01

    An improved large-signal equivalent-circuit model for SiGe HBTs based on the MEXTRAM model (level 504.5) is proposed. The proposed model takes into account the soft knee effect. The model keeps the main features of the MEXTRAM model even though some simplifications have been made in the equivalent circuit topology. This model is validated in DC and AC analyses for SiGe HBTs fabricated with 0.35-μm BiCMOS technology, 1 × 8 μm2 emitter area. Good agreement is achieved between the measured and modeled results for DC and S-parameters (from 50 MHz to 20 GHz), which shows that the proposed model is accurate and reliable. The model has been implemented in Verilog-A using the ADS circuit simulator.

  8. Modeling large reversible electric-field-induced strain in ferroelectric materials using 90° orientation switching

    Institute of Scientific and Technical Information of China (English)

    WANG LinXiang; LIU Rong; Roderick V.N.MELNIK

    2009-01-01

    Reversible large electric-field-induced strain caused by reversible orientation switchings in BaTiO3 is modeled using the Landau's theory of phase transition. A triple well free energy function is constructed, Each of its minima is associated with one of the polarization orientations involved, Nonlinear constitu-tive laws accounting for reversible orientation switchings and electrostriction effects are obtained by using thermodynamic equilibrium conditions. Hysteretic dynamics of one-dimensional structures is described by coupled nonlinear differential equations. Double hysteretic loops in the electric and me-chanic fields are both successfully modeled. Giant reversible electrostriction is modeled as a conse-quence of reversible orientation switchings via electro-mechanical couplings. Comparisons with ex-perimental results reported in literatures are presented.

  9. Modelling large-deforming fluid-saturated porous media using an Eulerian incremental formulation

    CERN Document Server

    Rohan, Eduard

    2016-01-01

    The paper deals with modelling fluid saturated porous media subject to large deformation. An Eulerian incremental formulation is derived using the problem imposed in the spatial configuration in terms of the equilibrium equation and the mass conservation. Perturbation of the hyperelastic porous medium is described by the Biot model which involves poroelastic coefficients and the permeability governing the Darcy flow. Using the material derivative with respect to a convection velocity field we obtain the rate formulation which allows for linearization of the residuum function. For a given time discretization with backward finite difference approximation of the time derivatives, two incremental problems are obtained which constitute the predictor and corrector steps of the implicit time-integration scheme. Conforming mixed finite element approximation in space is used. Validation of the numerical model implemented in the SfePy code is reported for an isotropic medium with a hyperelastic solid phase. The propose...

  10. Large eddy simulation of high frequency oscillating flow in an asymmetric branching airway model.

    Science.gov (United States)

    Nagels, Martin A; Cater, John E

    2009-11-01

    The implementation of artificial ventilation schemes is necessary when respiration fails. One approach involves the application of high frequency oscillatory ventilation (HFOV) to the respiratory system. Oscillatory airflow in the upper bronchial tree can be characterized by Reynolds numbers as high as 10(4), hence, the flow presents turbulent features. In this study, transitional and turbulent flow within an asymmetric bifurcating model of the upper airway during HFOV are studied using large eddy simulation (LES) methods. The flow, characterized by a peak Reynolds number of 8132, is analysed using a validated LES model of a three-dimensional branching geometry. The pressures, velocities, and vorticity within the flow are presented and compared with prior models for branching flow systems. The results demonstrate how pendelluft occurs at asymmetric branches within the respiratory system. These results may be useful in optimising treatments using HFOV methods.

  11. Modeling large reversible electric-field-induced strain in ferroelectric materials using 90° orientation switching

    Institute of Scientific and Technical Information of China (English)

    Roderick; V.; N.; MELNIK

    2009-01-01

    Reversible large electric-field-induced strain caused by reversible orientation switchings in BaTiO3 is modeled using the Landau’s theory of phase transition. A triple well free energy function is constructed. Each of its minima is associated with one of the polarization orientations involved. Nonlinear constitu- tive laws accounting for reversible orientation switchings and electrostriction effects are obtained by using thermodynamic equilibrium conditions. Hysteretic dynamics of one-dimensional structures is described by coupled nonlinear differential equations. Double hysteretic loops in the electric and me- chanic fields are both successfully modeled. Giant reversible electrostriction is modeled as a conse-quence of reversible orientation switchings via electro-mechanical couplings. Comparisons with ex-perimental results reported in literatures are presented.

  12. Autonomous motivation: involvement in physical activity, and perceived sport competence: structural and mediator models.

    Science.gov (United States)

    Bagøien, Tor Egil; Halvari, Hallgeir

    2005-02-01

    Students in upper secondary school (N = 231, M = 16.6 yr., SD = 1.6) were tested on involvement in physical activity, perceived sport competence, using the Perceived Competence Scale of Harter, and motivational regulation on the Self-regulation Questionnaire of Ryan and Connell. Correlations were positive among involvement in physical activity, autonomous motivation, and perceived sport competence. A hypothetical model indicated that autonomous motivation mediates the relation between perceived sport competence and involvement in physical activity. Although LISREL analysis supported this mediation, the best model fit of the data supported a structural model with involvement in physical activity (R2 = .63) to mediate between autonomous motivation and perceived competence (R2 = .47). Results are interpreted and discussed in terms of self-determination theory.

  13. Students' Involvement in Authentic Modelling Practices as Contexts in Chemistry Education

    Science.gov (United States)

    Prins, Gjalt T.; Bulte, Astrid M. W.; van Driel, Jan H.; Pilot, Albert

    2009-11-01

    In science education students should come to understand the nature and significance of models. A promising strategy to achieve this goal is using authentic modelling practices as contexts for meaningful learning of models and modelling. An authentic practice is defined as professionals working with common motives and purposes, pertaining to a similar type of procedure and applying relevant knowledge on the modelling issue they work on. In this study we evaluate whether the use of authentic practices initiates adequate students’ involvement. This was done by investigating students’ interests, ownership, familiarity and complexity. In addition, we evaluated students’ expressed modelling procedures in response to the modelling issues. We designed learning tasks which were enacted by a focus group of students. Three primary data sources were used to collect data. Firstly, a group discussion was organised in which students’ reflected on both authentic practices. Secondly, students filled in written questionnaires containing items on affective and cognitive aspects. Thirdly, the realised modelling procedures by students were analysed. The results show that students’ involvement was successfully initiated, evidenced by motivated students, willingness to continue and the completeness and quality of the realised modelling procedures. The design of the learning tasks proved to be successful in realising this involvement. The results obtained in this study support the strategy of using authentic modelling practices as contexts for meaningful learning of models and modelling.

  14. Virtualizing ancient Rome: 3D acquisition and modeling of a large plaster-of-Paris model of imperial Rome

    Science.gov (United States)

    Guidi, Gabriele; Frischer, Bernard; De Simone, Monica; Cioci, Andrea; Spinetti, Alessandro; Carosso, Luca; Micoli, Laura L.; Russo, Michele; Grasso, Tommaso

    2005-01-01

    Computer modeling through digital range images has been used for many applications, including 3D modeling of objects belonging to our cultural heritage. The scales involved range from small objects (e.g. pottery), to middle-sized works of art (statues, architectural decorations), up to very large structures (architectural and archaeological monuments). For any of these applications, suitable sensors and methodologies have been explored by different authors. The object to be modeled within this project is the "Plastico di Roma antica," a large plaster-of-Paris model of imperial Rome (16x17 meters) created in the last century. Its overall size therefore demands an acquisition approach typical of large structures, but it also is characterized extremely tiny details typical of small objects (houses are a few centimeters high; their doors, windows, etc. are smaller than 1 centimeter). This paper gives an account of the procedures followed for solving this "contradiction" and describes how a huge 3D model was acquired and generated by using a special metrology Laser Radar. The procedures for reorienting in a single reference system the huge point clouds obtained after each acquisition phase, thanks to the measurement of fixed redundant references, are described. The data set was split in smaller sub-areas 2 x 2 meters each for purposes of mesh editing. This subdivision was necessary owing to the huge number of points in each individual scan (50-60 millions). The final merge of the edited parts made it possible to create a single mesh. All these processes were made with software specifically designed for this project since no commercial package could be found that was suitable for managing such a large number of points. Preliminary models are presented. Finally, the significance of the project is discussed in terms of the overall project known as "Rome Reborn," of which the present acquisition is an important component.

  15. IBAR: Interacting boson model calculations for large system sizes

    Science.gov (United States)

    Casperson, R. J.

    2012-04-01

    Scaling the system size of the interacting boson model-1 (IBM-1) into the realm of hundreds of bosons has many interesting applications in the field of nuclear structure, most notably quantum phase transitions in nuclei. We introduce IBAR, a new software package for calculating the eigenvalues and eigenvectors of the IBM-1 Hamiltonian, for large numbers of bosons. Energies and wavefunctions of the nuclear states, as well as transition strengths between them, are calculated using these values. Numerical errors in the recursive calculation of reduced matrix elements of the d-boson creation operator are reduced by using an arbitrary precision mathematical library. This software has been tested for up to 1000 bosons using comparisons to analytic expressions. Comparisons have also been made to the code PHINT for smaller system sizes. Catalogue identifier: AELI_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AELI_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GNU General Public License version 3 No. of lines in distributed program, including test data, etc.: 28 734 No. of bytes in distributed program, including test data, etc.: 4 104 467 Distribution format: tar.gz Programming language: C++ Computer: Any computer system with a C++ compiler Operating system: Tested under Linux RAM: 150 MB for 1000 boson calculations with angular momenta of up to L=4 Classification: 17.18, 17.20 External routines: ARPACK (http://www.caam.rice.edu/software/ARPACK/) Nature of problem: Construction and diagonalization of large Hamiltonian matrices, using reduced matrix elements of the d-boson creation operator. Solution method: Reduced matrix elements of the d-boson creation operator have been stored in data files at machine precision, after being recursively calculated with higher than machine precision. The Hamiltonian matrix is calculated and diagonalized, and the requested transition strengths are calculated

  16. Adolescents and Music Media: Toward an Involvement-Mediational Model of Consumption and Self-Concept

    Science.gov (United States)

    Kistler, Michelle; Rodgers, Kathleen Boyce; Power, Thomas; Austin, Erica Weintraub; Hill, Laura Griner

    2010-01-01

    Using social cognitive theory and structural regression modeling, we examined pathways between early adolescents' music media consumption, involvement with music media, and 3 domains of self-concept (physical appearance, romantic appeal, and global self-worth; N=124). A mediational model was supported for 2 domains of self-concept. Music media…

  17. Bone marrow involvement in diffuse large B-cell lymphoma: correlation between FDG-PET uptake and type of cellular infiltrate

    Energy Technology Data Exchange (ETDEWEB)

    Paone, Gaetano; Itti, Emmanuel; Lin, Chieh; Meignan, Michel [Universite Paris 12, Department of Nuclear Medicine, Hopital Henri Mondor, Assistance Publique-Hopitaux de Paris (AP-HP), Creteil (France); Haioun, Corinne; Dupuis, Jehan [Universite Paris 12, Department of Clinical Haematology, Hopital Henri Mondor, Assistance Publique-Hopitaux de Paris (AP-HP), Creteil (France); Gaulard, Philippe [Universite Paris 12, Department of Pathology, Hopital Henri Mondor, Assistance Publique-Hopitaux de Paris (AP-HP), Creteil (France); Universite Paris 12, INSERM U841, Hopital Henri Mondor, Assistance Publique-Hopitaux de Paris (AP-HP), Creteil (France)

    2009-05-15

    To assess, in patients with diffuse large B-cell lymphoma (DLBCL), whether the low sensitivity of {sup 18}F-fluorodeoxyglucose positron emission tomography (FDG-PET) for bone marrow assessment may be explained by histological characteristics of the cellular infiltrate. From a prospective cohort of 110 patients with newly diagnosed aggressive lymphoma, 21 patients with DLBCL had bone marrow involvement. Pretherapeutic FDG-PET images were interpreted visually and semiquantitatively, then correlated with the type of cellular infiltrate and known prognostic factors. Of these 21 patients, 7 (33%) had lymphoid infiltrates with a prominent component of large transformed lymphoid cells (concordant bone marrow involvement, CBMI) and 14 (67%) had lymphoid infiltrates composed of small cells (discordant bone marrow involvement, DBMI). Only 10 patients (48%) had abnormal bone marrow FDG uptake, 6 of the 7 with CBMI and 4 of the 14 with DBMI. Therefore, FDG-PET positivity in the bone marrow was significantly associated with CBMI, while FDG-PET negativity was associated with DBMI (Fisher's exact test, p=0.024). There were no significant differences in gender, age and overall survival between patients with CBMI and DBMI, while the international prognostic index was significantly higher in patients with CBMI. Our study suggests that in patients with DLBCL with bone marrow involvement bone marrow FDG uptake depends on two types of infiltrate, comprising small (DBMI) or large (CBMI) cells. This may explain the apparent low sensitivity of FDG-PET previously reported for detecting bone marrow involvement. (orig.)

  18. The Effects of Group Relaxation Training/Large Muscle Exercise, and Parental Involvement on Attention to Task, Impulsivity, and Locus of Control among Hyperactive Boys.

    Science.gov (United States)

    Porter, Sally S.; Omizo, Michael M.

    1984-01-01

    The study examined the effects of group relaxation training/large muscle exercise and parental involvement on attention to task, impulsivity, and locus of control among 34 hyperactive boys. Following treatment both experimental groups recorded significantly higher attention to task, lower impulsivity, and lower locus of control scores. (Author/CL)

  19. Customer involvement in greening the supply chain: an interpretive structural modeling methodology

    Science.gov (United States)

    Kumar, Sanjay; Luthra, Sunil; Haleem, Abid

    2013-04-01

    The role of customers in green supply chain management needs to be identified and recognized as an important research area. This paper is an attempt to explore the involvement aspect of customers towards greening of the supply chain (SC). An empirical research approach has been used to collect primary data to rank different variables for effective customer involvement in green concept implementation in SC. An interpretive structural-based model has been presented, and variables have been classified using matrice d' impacts croises- multiplication appliqué a un classement analysis. Contextual relationships among variables have been established using experts' opinions. The research may help practicing managers to understand the interaction among variables affecting customer involvement. Further, this understanding may be helpful in framing the policies and strategies to green SC. Analyzing interaction among variables for effective customer involvement in greening SC to develop the structural model in the Indian perspective is an effort towards promoting environment consciousness.

  20. A model for the occurrence and analysis of ionic thermocurrent spectrum involving different orders of kinetics

    Indian Academy of Sciences (India)

    Jai Prakash

    2013-01-01

    Ionic thermocurrent (ITC) spectrum is much similar to a thermoluminescence (TL) glow curve involving monomolecular kinetics. It has already been reported that different orders of kinetics are involved in TL processes, which depend specifically on the extent of recombination and simultaneous retrapping. It is found that the involvement of different orders of kinetics in ITC spectrum depends on the experimental conditions of polarization and rate of rapid cooling. Consequently, order of kinetics involved in the ITC spectrum does not represent any specific feature of the system under investigation. An equation is developed which explains the occurrence of ITC spectrum involving any order of kinetics. Dielectric relaxation parameters, order of kinetics and approximate number of dipoles per unit volume are evaluated conveniently and easily following the proposed model.

  1. Reduction of large-scale numerical ground water flow models

    NARCIS (Netherlands)

    Vermeulen, P.T.M.; Heemink, A.W.; Testroet, C.B.M.

    2002-01-01

    Numerical models are often used for simulating ground water flow. Written in state space form, the dimension of these models is of the order of the number of model cells and can be very high (> million). As a result, these models are computationally very demanding, especially if many different scena

  2. Parallel runs of a large air pollution model on a grid of Sun computers

    DEFF Research Database (Denmark)

    Alexandrov, V.N.; Owczarz, W.; Thomsen, Per Grove

    2004-01-01

    Large -scale air pollution models can successfully be used in different environmental studies. These models are described mathematically by systems of partial differential equations. Splitting procedures followed by discretization of the spatial derivatives leads to several large systems of ordin...

  3. Validating the Runoff from the PRECIS Model Using a Large-Scale Routing Model

    Institute of Scientific and Technical Information of China (English)

    CAO Lijuan; DONG Wenjie; XU Yinlong; ZHANG Yong; Michael SPARROW

    2007-01-01

    The streamflow over the Yellow River basin is simulated using the PRECIS (Providing REgional Climates for Impacts Studies) regional climate model driven by 15-year (1979-1993) ECMWF reanalysis data as the initial and lateral boundary conditions and an off-line large-scale routing model (LRM). The LRM uses physical catchment and river channel information and allows streamflow to be predicted for large continental rivers with a 1°× 1° spatial resolution. The results show that the PRECIS model can reproduce the general southeast to northwest gradient distribution of the precipitation over the Yellow River basin. The PRECISLRM model combination has the capability to simulate the seasonal and annual streamflow over the Yellow River basin. The simulated streamflow is generally coincident with the naturalized streamflow both in timing and in magnitude.

  4. Expanding the Work Phases Model: User and Expert Involvement in the Construction of Online Specialised Dictionaries

    DEFF Research Database (Denmark)

    Leroyer, Patrick

    The purpose of this article is to establish new proposals for the lexicographic process and the involvement of experts and users in the construction of online specialised dictionaries. It is argued that the ENeL action should also have a view to the development of innovative theories...... and methodologies for the construction of online specialised dictionaries, and a new model for user and expert involvement is proposed....

  5. Phenomenology of Large Extra Dimensions Models at Hadrons Colliders using Monte Carlo Techniques (Spin-2 Graviton)

    CERN Document Server

    Bakhet, Nady; Hussein, Tarek

    2015-01-01

    Large Extra Dimensions Models have been proposed to remove the hierarchy problem and give an explanation why the gravity is so much weaker than the other three forces. In this work, we present an analysis of Monte Carlo data events for new physics signatures of spin-2 Graviton in context of ADD model with total dimensions $D=4+\\delta,$ $\\delta = 1,2,3,4,5,6 $ where $ \\delta $ is the extra special dimension, this model involves missing momentum $P_{T}^{miss}$ in association with jet in the final state via the process $pp(\\bar{p}) \\rightarrow G+jet$, Also, we present an analysis in context of the RS model with 5-dimensions via the process $pp(\\bar{p}) \\rightarrow G+jet$, $G \\rightarrow e^{+}e^{-}$ with final state $e^{+}e^{-}+jet$. We used Monte Carlo event generator Pythia8 to produce efficient signal selection rules at the Large Hadron Collider with $\\sqrt{s}$=14TeV and at the Tevatron $\\sqrt{s}$=1.96TeV .

  6. MODELLING OF CARBON MONOXIDE AIR POLLUTION IN LARG CITIES BY EVALUETION OF SPECTRAL LANDSAT8 IMAGES

    Directory of Open Access Journals (Sweden)

    M. Hamzelo

    2015-12-01

    Full Text Available Air pollution in large cities is one of the major problems that resolve and reduce it need multiple applications and environmental management. Of The main sources of this pollution is industrial activities, urban and transport that enter large amounts of contaminants into the air and reduces its quality. With Variety of pollutants and high volume manufacturing, local distribution of manufacturing centers, Testing and measuring emissions is difficult. Substances such as carbon monoxide, sulfur dioxide, and unburned hydrocarbons and lead compounds are substances that cause air pollution and carbon monoxide is most important. Today, data exchange systems, processing, analysis and modeling is of important pillars of management system and air quality control. In this study, using the spectral signature of carbon monoxide gas as the most efficient gas pollution LANDSAT8 images in order that have better spatial resolution than appropriate spectral bands and weather meters،SAM classification algorithm and Geographic Information System (GIS , spatial distribution of carbon monoxide gas in Tehran over a period of one year from the beginning of 2014 until the beginning of 2015 at 11 map have modeled and then to the model valuation ،created maps were compared with the map provided by the Tehran quality comparison air company. Compare involved plans did with the error matrix and results in 4 types of care; overall, producer, user and kappa coefficient was investigated. Results of average accuracy were about than 80%, which indicates the fit method and data used for modeling.

  7. Modelling of Carbon Monoxide Air Pollution in Larg Cities by Evaluetion of Spectral LANDSAT8 Images

    Science.gov (United States)

    Hamzelo, M.; Gharagozlou, A.; Sadeghian, S.; Baikpour, S. H.; Rajabi, A.

    2015-12-01

    Air pollution in large cities is one of the major problems that resolve and reduce it need multiple applications and environmental management. Of The main sources of this pollution is industrial activities, urban and transport that enter large amounts of contaminants into the air and reduces its quality. With Variety of pollutants and high volume manufacturing, local distribution of manufacturing centers, Testing and measuring emissions is difficult. Substances such as carbon monoxide, sulfur dioxide, and unburned hydrocarbons and lead compounds are substances that cause air pollution and carbon monoxide is most important. Today, data exchange systems, processing, analysis and modeling is of important pillars of management system and air quality control. In this study, using the spectral signature of carbon monoxide gas as the most efficient gas pollution LANDSAT8 images in order that have better spatial resolution than appropriate spectral bands and weather meters،SAM classification algorithm and Geographic Information System (GIS ), spatial distribution of carbon monoxide gas in Tehran over a period of one year from the beginning of 2014 until the beginning of 2015 at 11 map have modeled and then to the model valuation ،created maps were compared with the map provided by the Tehran quality comparison air company. Compare involved plans did with the error matrix and results in 4 types of care; overall, producer, user and kappa coefficient was investigated. Results of average accuracy were about than 80%, which indicates the fit method and data used for modeling.

  8. Advances and visions in large-scale hydrological modelling: findings from the 11th workshop on large-scale hydrological modelling

    NARCIS (Netherlands)

    Döll, P.; Berkhoff, K.; Bormann, H.; Fohrer, N.; Gerten, D.; Hagemann, S.; Krol, Martinus S.

    2008-01-01

    Large-scale hydrological modelling has become increasingly wide-spread during the last decade. An annual workshop series on large-scale hydrological modelling has provided, since 1997, a forum to the German-speaking community for discussing recent developments and achievements in this research area.

  9. Large animal models of rare genetic disorders: sheep as phenotypically relevant models of human genetic disease.

    Science.gov (United States)

    Pinnapureddy, Ashish R; Stayner, Cherie; McEwan, John; Baddeley, Olivia; Forman, John; Eccles, Michael R

    2015-09-02

    Animals that accurately model human disease are invaluable in medical research, allowing a critical understanding of disease mechanisms, and the opportunity to evaluate the effect of therapeutic compounds in pre-clinical studies. Many types of animal models are used world-wide, with the most common being small laboratory animals, such as mice. However, rodents often do not faithfully replicate human disease, despite their predominant use in research. This discordancy is due in part to physiological differences, such as body size and longevity. In contrast, large animal models, including sheep, provide an alternative to mice for biomedical research due to their greater physiological parallels with humans. Completion of the full genome sequences of many species, and the advent of Next Generation Sequencing (NGS) technologies, means it is now feasible to screen large populations of domesticated animals for genetic variants that resemble human genetic diseases, and generate models that more accurately model rare human pathologies. In this review, we discuss the notion of using sheep as large animal models, and their advantages in modelling human genetic disease. We exemplify several existing naturally occurring ovine variants in genes that are orthologous to human disease genes, such as the Cln6 sheep model for Batten disease. These, and other sheep models, have contributed significantly to our understanding of the relevant human disease process, in addition to providing opportunities to trial new therapies in animals with similar body and organ size to humans. Therefore sheep are a significant species with respect to the modelling of rare genetic human disease, which we summarize in this review.

  10. Modeling a Dry Etch Process for Large-Area Devices

    Energy Technology Data Exchange (ETDEWEB)

    Buss, R.J.; Hebner, G.A.; Ruby, D.S.; Yang, P.

    1999-07-28

    There has been considerable interest in developing dry processes which can effectively replace wet processing in the manufacture of large area photovoltaic devices. Environmental and health issues are a driver for this activity because wet processes generally increase worker exposure to toxic and hazardous chemicals and generate large volumes of liquid hazardous waste. Our work has been directed toward improving the performance of screen-printed solar cells while using plasma processing to reduce hazardous chemical usage.

  11. Dynamics Modeling and Simulation of Large Transport Airplanes in Upset Conditions

    Science.gov (United States)

    Foster, John V.; Cunningham, Kevin; Fremaux, Charles M.; Shah, Gautam H.; Stewart, Eric C.; Rivers, Robert A.; Wilborn, James E.; Gato, William

    2005-01-01

    As part of NASA's Aviation Safety and Security Program, research has been in progress to develop aerodynamic modeling methods for simulations that accurately predict the flight dynamics characteristics of large transport airplanes in upset conditions. The motivation for this research stems from the recognition that simulation is a vital tool for addressing loss-of-control accidents, including applications to pilot training, accident reconstruction, and advanced control system analysis. The ultimate goal of this effort is to contribute to the reduction of the fatal accident rate due to loss-of-control. Research activities have involved accident analyses, wind tunnel testing, and piloted simulation. Results have shown that significant improvements in simulation fidelity for upset conditions, compared to current training simulations, can be achieved using state-of-the-art wind tunnel testing and aerodynamic modeling methods. This paper provides a summary of research completed to date and includes discussion on key technical results, lessons learned, and future research needs.

  12. Childhood craniopharyngioma: greater hypothalamic involvement before surgery is associated with higher homeostasis model insulin resistance index

    Directory of Open Access Journals (Sweden)

    Sainte-Rose Christian

    2009-04-01

    Full Text Available Abstract Background Obesity seems to be linked to the hypothalamic involvement in craniopharyngioma. We evaluated the pre-surgery relationship between the degree of this involvement on magnetic resonance imaging and insulin resistance, as evaluated by the homeostasis model insulin resistance index (HOMA. As insulin-like growth factor 1, leptin, soluble leptin receptor (sOB-R and ghrelin may also be involved, we compared their plasma concentrations and their link to weight change. Methods 27 children with craniopharyngioma were classified as either grade 0 (n = 7, no hypothalamic involvement, grade 1 (n = 8, compression without involvement, or grade 2 (n = 12, severe involvement. Results Despite having similar body mass indexes (BMI, the grade 2 patients had higher glucose, insulin and HOMA before surgery than the grade 0 (P = 0.02, The data for the whole population before and 6–18 months after surgery showed increases in BMI (P Conclusion The hypothalamic involvement by the craniopharyngioma before surgery seems to determine the degree of insulin resistance, regardless of the BMI. The pre-surgery HOMA values were correlated with the post-surgery weight gain. This suggests that obesity should be prevented by reducing inn secretion in those cases with hypothalamic involvement.

  13. Evaluation of drought propagation in an ensemble mean of large-scale hydrological models

    NARCIS (Netherlands)

    Loon, van A.F.; Huijgevoort, van M.H.J.; Lanen, van H.A.J.

    2012-01-01

    Hydrological drought is increasingly studied using large-scale models. It is, however, not sure whether large-scale models reproduce the development of hydrological drought correctly. The pressing question is how well do large-scale models simulate the propagation from meteorological to hydrological

  14. Long-Run Properties of Large-Scale Macroeconometric Models

    OpenAIRE

    Kenneth F. WALLIS-; John D. WHITLEY

    1987-01-01

    We consider alternative approaches to the evaluation of the long-run properties of dynamic nonlinear macroeconometric models, namely dynamic simulation over an extended database, or the construction and direct solution of the steady-state version of the model. An application to a small model of the UK economy is presented. The model is found to be unstable, but a stable form can be produced by simple alterations to the structure.

  15. A SUSY SO(10) model with large tan$\\beta$

    CERN Document Server

    Lazarides, G

    1994-01-01

    We construct a supersymmetric SO(10) model with the asymptotic relation tan\\beta \\simeq m_t/m_b automatically arising from its structure. The model retains the significant Minimal Supersymmetric Standard Model predictions for sin^2 \\theta_w and \\alpha_s and contains an automatic Z_2 matter parity. Proton decay through d=5 operators is sufficiently suppressed. It is remarkable that no global symmetries need to be imposed on the model.

  16. Eulerian models for particle trajectory crossing in turbulent flows over a large range of Stokes numbers

    Science.gov (United States)

    Fox, Rodney O.; Vie, Aymeric; Laurent, Frederique; Chalons, Christophe; Massot, Marc

    2012-11-01

    Numerous applications involve a disperse phase carried by a gaseous flow. To simulate such flows, one can resort to a number density function (NDF) governed a kinetic equation. Traditionally, Lagrangian Monte-Carlo methods are used to solve for the NDF, but are expensive as the number of numerical particles needed must be large to control statistical errors. Moreover, such methods are not well adapted to high-performance computing because of the intrinsic inhomogeneity of the NDF. To overcome these issues, Eulerian methods can be used to solve for the moments of the NDF resulting in an unclosed Eulerian system of hyperbolic conservation laws. To obtain closure, in this work a multivariate bi-Gaussian quadrature is used, which can account for particle trajectory crossing (PTC) over a large range of Stokes numbers. This closure uses up to four quadrature points in 2-D velocity phase space to capture large-scale PTC, and an anisotropic Gaussian distribution around each quadrature point to model small-scale PTC. Simulations of 2-D particle-laden isotropic turbulence at different Stokes numbers are employed to validate the Eulerian models against results from the Lagrangian approach. Good agreement is found for the number density fields over the entire range of Stokes numbers tested. Research carried out at the Center for Turbulence Research 2012 Summer Program.

  17. The Density Matrix Renormalization Group Method and Large-Scale Nuclear Shell-Model Calculations

    CERN Document Server

    Dimitrova, S S; Pittel, S; Stoitsov, M V

    2002-01-01

    The particle-hole Density Matrix Renormalization Group (p-h DMRG) method is discussed as a possible new approach to large-scale nuclear shell-model calculations. Following a general description of the method, we apply it to a class of problems involving many identical nucleons constrained to move in a single large j-shell and to interact via a pairing plus quadrupole interaction. A single-particle term that splits the shell into degenerate doublets is included so as to accommodate the physics of a Fermi surface in the problem. We apply the p-h DMRG method to this test problem for two $j$ values, one for which the shell model can be solved exactly and one for which the size of the hamiltonian is much too large for exact treatment. In the former case, the method is able to reproduce the exact results for the ground state energy, the energies of low-lying excited states, and other observables with extreme precision. In the latter case, the results exhibit rapid exponential convergence, suggesting the great promi...

  18. Large and giant medial sphenoid wing meningiomas involving vascular structures: clinical features and management experience in 53 patients

    Institute of Scientific and Technical Information of China (English)

    YANG Jun; MA Shun-chang; LIU Yan-hong; WEI Lin; ZHANG Chun-yang; QI Jian-fa; YU Chun-jiang

    2013-01-01

    Background Large and giant medial sphenoid wing meningiomas that are located deeply in the skull base where they are closely bounded by cavernous sinus,optic nerve,and internal carotid artery make the gross resection hard to achieve.Also,this kind of meningiomas is often accompanied by a series of severe complications.Therefore,it was regarded as a formidable challenge to even the most experienced neurosurgeons.This study aimed to investigate the clinical features and management experience of patients with large and giant medial sphenoid wing meningiomas.Methods In this study,53 patients (33 female and 20 male,mean age of 47.5 years) with large and giant medial sphenoid wing meningiomas were treated surgically between April 2004 to March 2012,with their clinical features analyzed,management experience collected,and treatment results investigated retrospectively.Results In this study,gross total resection (Simpson Ⅰ and Ⅱ) was applied in 44 patients (83%).Fifty-three patients had accepted the routine computed tomography scan and magnetic resonance imaging scan as postoperative neuroradiological evaluation.Their performance showed surgical complications of vascular lesions and helped us evaluate patients' conditions,respectively.Meanwhile,the drugs resisting cerebral angiospasm,such as Nimodipine,were infused in every postoperative patient through vein as routine.As a result,11 patients (21%) were found to have secondary injury of cranial nerves Ⅱ,Ⅲ,and Ⅳ,and nine patients got recovered during the long-term observing follow-up period.Temporary surgical complications of vascular lesions occurred after surgery,such as cerebral angiospasm,ischemia,and edema;24 patients (45%) appeared to have infarction and dyskinesia of limbs.Overall,visual ability was improved in 41 patients (77%).No patient died during the process.Conclusions Microsurgical treatment may be the most effective method for the large and giant medial sphenoid wing meningiomas.The surgical

  19. Large scale modelling of catastrophic floods in Italy

    Science.gov (United States)

    Azemar, Frédéric; Nicótina, Ludovico; Sassi, Maximiliano; Savina, Maurizio; Hilberts, Arno

    2017-04-01

    The RMS European Flood HD model® is a suite of country scale flood catastrophe models covering 13 countries throughout continental Europe and the UK. The models are developed with the goal of supporting risk assessment analyses for the insurance industry. Within this framework RMS is developing a hydrologic and inundation model for Italy. The model aims at reproducing the hydrologic and hydraulic properties across the domain through a modeling chain. A semi-distributed hydrologic model that allows capturing the spatial variability of the runoff formation processes is coupled with a one-dimensional river routing algorithm and a two-dimensional (depth averaged) inundation model. This model setup allows capturing the flood risk from both pluvial (overland flow) and fluvial flooding. Here we describe the calibration and validation methodologies for this modelling suite applied to the Italian river basins. The variability that characterizes the domain (in terms of meteorology, topography and hydrologic regimes) requires a modeling approach able to represent a broad range of meteo-hydrologic regimes. The calibration of the rainfall-runoff and river routing models is performed by means of a genetic algorithm that identifies the set of best performing parameters within the search space over the last 50 years. We first establish the quality of the calibration parameters on the full hydrologic balance and on individual discharge peaks by comparing extreme statistics to observations over the calibration period on several stations. The model is then used to analyze the major floods in the country; we discuss the different meteorological setup leading to the historical events and the physical mechanisms that induced these floods. We can thus assess the performance of RMS' hydrological model in view of the physical mechanisms leading to flood and highlight the main controls on flood risk modelling throughout the country. The model's ability to accurately simulate antecedent

  20. Investigation of Deep Inelastic Scattering Processes Involving Large p$_{T}$ Direct Photons in the Final State

    CERN Multimedia

    2002-01-01

    This experiment will investigate various aspects of photon-parton scattering and will be performed in the H2 beam of the SPS North Area with high intensity hadron beams up to 350 GeV/c. \\item a) The directly produced photon yield in deep inelastic hadron-hadron collisions. Large p^T direct photons from hadronic interactions are presumably a result of a simple annihilation process of quarks and antiquarks or of a QCD-Compton process. The relative contribution of the two processes can be studied by using various incident beam projectiles @p|+, @p|-, p and in the future @*. \\item b) The correlations between directly produced photons and their accompanying hadronic jets. We will examine events with a large p^T direct photon for away-side jets. If jets are recognised their properties will be investigated. Differences between a gluon and a quark jet may become observable by comparing reactions where valence quark annihilations (away-side jet originates from a gluon) dominate over the Q (away-side jet originates fro...

  1. Large-scale analysis of conserved rare codon clusters suggests an involvement in co-translational molecular recognition events.

    Science.gov (United States)

    Chartier, Matthieu; Gaudreault, Francis; Najmanovich, Rafael

    2012-06-01

    An increasing amount of evidence from experimental and computational analysis suggests that rare codon clusters are functionally important for protein activity. Most of the studies on rare codon clusters were performed on a limited number of proteins or protein families. In the present study, we present the Sherlocc program and how it can be used for large scale protein family analysis of evolutionarily conserved rare codon clusters and their relation to protein function and structure. This large-scale analysis was performed using the whole Pfam database covering over 70% of the known protein sequence universe. Our program Sherlocc, detects statistically relevant conserved rare codon clusters and produces a user-friendly HTML output. Statistically significant rare codon clusters were detected in a multitude of Pfam protein families. The most statistically significant rare codon clusters were predominantly identified in N-terminal Pfam families. Many of the longest rare codon clusters are found in membrane-related proteins which are required to interact with other proteins as part of their function, for example in targeting or insertion. We identified some cases where rare codon clusters can play a regulating role in the folding of catalytically important domains. Our results support the existence of a widespread functional role for rare codon clusters across species. Finally, we developed an online filter-based search interface that provides access to Sherlocc results for all Pfam families. The Sherlocc program and search interface are open access and are available at http://bcb.med.usherbrooke.ca

  2. Lattice Boltzmann modeling of multiphase flows at large density ratio with an improved pseudopotential model

    CERN Document Server

    Li, Q; Li, X J

    2012-01-01

    Owing to its conceptual simplicity and computational efficiency, the pseudopotential multiphase lattice Boltzmann (LB) model has attracted significant attention since its emergence. In this work, we aim to extend the pseudopotential LB model to the simulations of multiphase flows at large density ratio and relatively high Reynolds number. First, based on our recent work [Li et al., Phys. Rev. E. 86, 016709 (2012)], an improved forcing scheme is proposed for the multiple-relaxation-time (MRT) pseudopotential LB model in order to achieve thermodynamic consistency and large density ratio in the model. Next, through investigating the effects of the parameter a in the Carnahan-Starling equation of state, we find that, as compared with a = 1, a = 0.25 is capable of greatly reducing the magnitude of the spurious currents at large density ratio. Furthermore, it is found that a lower liquid viscosity can be gained in the pseudopotential LB model by increasing the kinematic viscosity ratio between the vapor and liquid ...

  3. Large scale debris-flow hazard assessment: a geotechnical approach and GIS modelling

    Directory of Open Access Journals (Sweden)

    G. Delmonaco

    2003-01-01

    Full Text Available A deterministic distributed model has been developed for large-scale debris-flow hazard analysis in the basin of River Vezza (Tuscany Region – Italy. This area (51.6 km 2 was affected by over 250 landslides. These were classified as debris/earth flow mainly involving the metamorphic geological formations outcropping in the area, triggered by the pluviometric event of 19 June 1996. In the last decades landslide hazard and risk analysis have been favoured by the development of GIS techniques permitting the generalisation, synthesis and modelling of stability conditions on a large scale investigation (>1:10 000. In this work, the main results derived by the application of a geotechnical model coupled with a hydrological model for the assessment of debris flows hazard analysis, are reported. This analysis has been developed starting by the following steps: landslide inventory map derived by aerial photo interpretation, direct field survey, generation of a database and digital maps, elaboration of a DTM and derived themes (i.e. slope angle map, definition of a superficial soil thickness map, geotechnical soil characterisation through implementation of a backanalysis on test slopes, laboratory test analysis, inference of the influence of precipitation, for distinct return times, on ponding time and pore pressure generation, implementation of a slope stability model (infinite slope model and generalisation of the safety factor for estimated rainfall events with different return times. Such an approach has allowed the identification of potential source areas of debris flow triggering. This is used to detected precipitation events with estimated return time of 10, 50, 75 and 100 years. The model shows a dramatic decrease of safety conditions for the simulation when is related to a 75 years return time rainfall event. It corresponds to an estimated cumulated daily intensity of 280–330 mm. This value can be considered the hydrological triggering

  4. Advances and visions in large-scale hydrological modelling: findings from the 11th Workshop on Large-Scale Hydrological Modelling

    Directory of Open Access Journals (Sweden)

    P. Döll

    2008-10-01

    Full Text Available Large-scale hydrological modelling has become increasingly wide-spread during the last decade. An annual workshop series on large-scale hydrological modelling has provided, since 1997, a forum to the German-speaking community for discussing recent developments and achievements in this research area. In this paper we present the findings from the 2007 workshop which focused on advances and visions in large-scale hydrological modelling. We identify the state of the art, difficulties and research perspectives with respect to the themes "sensitivity of model results", "integrated modelling" and "coupling of processes in hydrosphere, atmosphere and biosphere". Some achievements in large-scale hydrological modelling during the last ten years are presented together with a selection of remaining challenges for the future.

  5. Modeling Temporal Behavior in Large Networks: A Dynamic Mixed-Membership Model

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, R; Gallagher, B; Neville, J; Henderson, K

    2011-11-11

    Given a large time-evolving network, how can we model and characterize the temporal behaviors of individual nodes (and network states)? How can we model the behavioral transition patterns of nodes? We propose a temporal behavior model that captures the 'roles' of nodes in the graph and how they evolve over time. The proposed dynamic behavioral mixed-membership model (DBMM) is scalable, fully automatic (no user-defined parameters), non-parametric/data-driven (no specific functional form or parameterization), interpretable (identifies explainable patterns), and flexible (applicable to dynamic and streaming networks). Moreover, the interpretable behavioral roles are generalizable, computationally efficient, and natively supports attributes. We applied our model for (a) identifying patterns and trends of nodes and network states based on the temporal behavior, (b) predicting future structural changes, and (c) detecting unusual temporal behavior transitions. We use eight large real-world datasets from different time-evolving settings (dynamic and streaming). In particular, we model the evolving mixed-memberships and the corresponding behavioral transitions of Twitter, Facebook, IP-Traces, Email (University), Internet AS, Enron, Reality, and IMDB. The experiments demonstrate the scalability, flexibility, and effectiveness of our model for identifying interesting patterns, detecting unusual structural transitions, and predicting the future structural changes of the network and individual nodes.

  6. Light dilaton in the large N tricritical O (N ) model

    Science.gov (United States)

    Omid, Hamid; Semenoff, Gordon W.; Wijewardhana, L. C. R.

    2016-12-01

    The leading order of the large N limit of the O (N ) symmetric phi-six theory in three dimensions has a phase which exhibits spontaneous breaking of scale symmetry accompanied by a massless dilaton which is a Goldstone boson. At the next-to-leading order in large N , the phi-six coupling has a beta function of order 1 /N and it is expected that the dilaton acquires a small mass, proportional to the beta function and the condensate. In this article, we show that this "light dilaton" is actually a tachyon. This indicates an instability of the phase of the theory with spontaneously broken approximate scale invariance.

  7. The standard model Higgs search at the large hadron collider

    Indian Academy of Sciences (India)

    Satyaki Bhattacharya; on behalf of the CMS and the ATLAS Collaborations

    2007-11-01

    The experiments at the large hadron collider (LHC) will probe for Higgs boson in the mass range between the lower bound on the Higgs mass set by the experiments at the large electron positron collider (LEP) and the unitarity bound (∼ 1 TeV). Strategies are being developed to look for signatures of Higgs boson and measure its properties. In this paper results from full detector simulation-based studies on Higgs discovery from both ATLAS and CMS experiments at the LHC will be presented. Results of simulation studies on Higgs coupling measurement at LHC will be discussed.

  8. Large-scale analysis of conserved rare codon clusters suggests an involvement in co-translational molecular recognition events

    Science.gov (United States)

    Chartier, Matthieu; Gaudreault, Francis; Najmanovich, Rafael

    2012-01-01

    Motivation: An increasing amount of evidence from experimental and computational analysis suggests that rare codon clusters are functionally important for protein activity. Most of the studies on rare codon clusters were performed on a limited number of proteins or protein families. In the present study, we present the Sherlocc program and how it can be used for large scale protein family analysis of evolutionarily conserved rare codon clusters and their relation to protein function and structure. This large-scale analysis was performed using the whole Pfam database covering over 70% of the known protein sequence universe. Our program Sherlocc, detects statistically relevant conserved rare codon clusters and produces a user-friendly HTML output. Results: Statistically significant rare codon clusters were detected in a multitude of Pfam protein families. The most statistically significant rare codon clusters were predominantly identified in N-terminal Pfam families. Many of the longest rare codon clusters are found in membrane-related proteins which are required to interact with other proteins as part of their function, for example in targeting or insertion. We identified some cases where rare codon clusters can play a regulating role in the folding of catalytically important domains. Our results support the existence of a widespread functional role for rare codon clusters across species. Finally, we developed an online filter-based search interface that provides access to Sherlocc results for all Pfam families. Availability: The Sherlocc program and search interface are open access and are available at http://bcb.med.usherbrooke.ca Contact: rafael.najmanovich@usherbrooke.ca Supplementary information: Supplementary data are available at Bioinformatics online. PMID:22467916

  9. Modelling the spreading of large-scale wildland fires

    CERN Document Server

    Drissi, Mohamed

    2014-01-01

    The objective of the present study is twofold. First, the last developments and validation results of a hybrid model designed to simulate fire patterns in heterogeneous landscapes are presented. The model combines the features of a stochastic small-world network model with those of a deterministic semi-physical model of the interaction between burning and non-burning cells that strongly depends on local conditions of wind, topography, and vegetation. Radiation and convection from the flaming zone, and radiative heat loss to the ambient are considered in the preheating process of unburned cells. Second, the model is applied to an Australian grassland fire experiment as well as to a real fire that took place in Corsica in 2009. Predictions compare favorably to experiments in terms of rate of spread, area and shape of the burn. Finally, the sensitivity of the model outcomes (here the rate of spread) to six input parameters is studied using a two-level full factorial design.

  10. Hybrid transfinite element modeling/analysis of nonlinear heat conduction problems involving phase change

    Science.gov (United States)

    Tamma, Kumar K.; Railkar, Sudhir B.

    1988-01-01

    The present paper describes the applicability of hybrid transfinite element modeling/analysis formulations for nonlinear heat conduction problems involving phase change. The methodology is based on application of transform approaches and classical Galerkin schemes with finite element formulations to maintain the modeling versatility and numerical features for computational analysis. In addition, in conjunction with the above, the effects due to latent heat are modeled using enthalpy formulations to enable a physically realistic approximation to be dealt computationally for materials exhibiting phase change within a narrow band of temperatures. Pertinent details of the approach and computational scheme adapted are described in technical detail. Numerical test cases of comparative nature are presented to demonstrate the applicability of the proposed formulations for numerical modeling/analysis of nonlinear heat conduction problems involving phase change.

  11. Experimental Investigation of Very Large Model Wind Turbine Arrays

    Science.gov (United States)

    Charmanski, Kyle; Wosnik, Martin

    2013-11-01

    The decrease in energy yield in large wind farms (array losses) and associated revenue losses can be significant. When arrays are sufficiently large they can reach what is known as a fully developed wind turbine array boundary layer, or fully developed wind farm condition. This occurs when the turbulence statistics and the structure of the turbulence, within and above a wind farm, as well as the performance of the turbines remain the same from one row to the next. The study of this condition and how it is affected by parameters such as turbine spacing, power extraction, tip speed ratio, etc. is important for the optimization of large wind farms. An experimental investigation of the fully developed wind farm condition was conducted using a large array of porous disks (upstream) and realistically scaled 3-bladed wind turbines with a diameter of 0.25m. The turbines and porous disks were placed inside a naturally grown turbulent boundary layer in the 6m × 2.5m × 72m test section of the UNH Flow Physics Facility which can achieve test section velocities of up to 14 m/s and Reynolds numbers δ+ = δuτ / ν ~ 20 , 000 . Power, rate of rotation and rotor thrust were measured for select turbines, and hot-wire anemometry was used for flow measurements.

  12. Identification, structural, and biochemical characterization of a group of large Csn2 proteins involved in CRISPR-mediated bacterial immunity.

    Science.gov (United States)

    Lee, Kwang-Hoon; Lee, Seong-Gyu; Eun Lee, Kyung; Jeon, Hyesung; Robinson, Howard; Oh, Byung-Ha

    2012-11-01

    Many prokaryotic organisms acquire immunity against foreign genetic material by incorporating a short segment of foreign DNA called spacer into chromosomal loci, termed clustered regularly interspaced short palindromic repeats (CRISPRs). The encoded RNAs are processed into small fragments that guide the silencing of the invading genetic elements. The CRISPR-associated (Cas) proteins are the main executioners of these processes. Herein, we report the crystal structure of Stu0660 of Streptococcus thermophilus, a Cas protein involved in the acquisition of new spacers. By homotetramerization, Stu0660 forms a central channel which is decorated with basic amino acids and binds linear double-stranded DNA (dsDNA), but not circular dsDNA. Despite undetectably low sequence similarity, two N-terminal domains of Stu0660 are similar to the entire structure of an Enterococcus faecalis Csn2 protein, which also forms a homotetramer and binds dsDNA. Thus, this work identifies a previously unknown group of Stu0660-like Csn2 proteins (∼350 residues), which are larger than the known canonical Csn2 proteins (∼220 residues) by containing an extra C-terminal domain. The commonly present central channel in the two subgroups appears as a design to selectively interact with linear dsDNA. Copyright © 2012 Wiley Periodicals, Inc.

  13. Transcriptomic and proteomic responses of Serratia marcescens to spaceflight conditions involve large-scale changes in metabolic pathways

    Science.gov (United States)

    Wang, Yajuan; Yuan, Yanting; Liu, Jinwen; Su, Longxiang; Chang, De; Guo, Yinghua; Chen, Zhenhong; Fang, Xiangqun; Wang, Junfeng; Li, Tianzhi; Zhou, Lisha; Fang, Chengxiang; Yang, Ruifu; Liu, Changting

    2014-04-01

    The microgravity environment of spaceflight expeditions has been associated with altered microbial responses. This study explores the characterization of Serratia marcescensis grown in a spaceflight environment at the phenotypic, transcriptomic and proteomic levels. From November 1, 2011 to November 17, 2011, a strain of S. marcescensis was sent into space for 398 h on the Shenzhou VIII spacecraft, and ground simulation was performed as a control (LCT-SM213). After the flight, two mutant strains (LCT-SM166 and LCT-SM262) were selected for further analysis. Although no changes in the morphology, post-culture growth kinetics, hemolysis or antibiotic sensitivity were observed, the two mutant strains exhibited significant changes in their metabolic profiles after exposure to spaceflight. Enrichment analysis of the transcriptome showed that the differentially expressed genes of the two spaceflight strains and the ground control strain mainly included those involved in metabolism and degradation. The proteome revealed that changes at the protein level were also associated with metabolic functions, such as glycolysis/gluconeogenesis, pyruvate metabolism, arginine and proline metabolism and the degradation of valine, leucine and isoleucine. In summary S. marcescens showed alterations primarily in genes and proteins that were associated with metabolism under spaceflight conditions, which gave us valuable clues for future research.

  14. Evaluating HapMap SNP data transferability in a large-scale genotyping project involving 175 cancer-associated genes.

    Science.gov (United States)

    Ribas, Gloria; González-Neira, Anna; Salas, Antonio; Milne, Roger L; Vega, Ana; Carracedo, Begoña; González, Emilio; Barroso, Eva; Fernández, Lara P; Yankilevich, Patricio; Robledo, Mercedes; Carracedo, Angel; Benítez, Javier

    2006-02-01

    One of the many potential uses of the HapMap project is its application to the investigation of complex disease aetiology among a wide range of populations. This study aims to assess the transferability of HapMap SNP data to the Spanish population in the context of cancer research. We have carried out a genotyping study in Spanish subjects involving 175 candidate cancer genes using an indirect gene-based approach and compared results with those for HapMap CEU subjects. Allele frequencies were very consistent between the two samples, with a high positive correlation (R) of 0.91 (PHapMap CEU data using pairwise r (2) thresholds of 0.8 and 0.5 was assessed by applying these to the Spanish and current HapMap data for 66 genes. In general, the HapMap tagSNPs performed very well. Our results show generally high concordance with HapMap data in allele frequencies and haplotype distributions and confirm the applicability of HapMap SNP data to the study of complex diseases among the Spanish population.

  15. Fast Kalman-like filtering for large-dimensional linear and Gaussian state-space models

    KAUST Repository

    Ait-El-Fquih, Boujemaa

    2015-08-13

    This paper considers the filtering problem for linear and Gaussian state-space models with large dimensions, a setup in which the optimal Kalman Filter (KF) might not be applicable owing to the excessive cost of manipulating huge covariance matrices. Among the most popular alternatives that enable cheaper and reasonable computation is the Ensemble KF (EnKF), a Monte Carlo-based approximation. In this paper, we consider a class of a posteriori distributions with diagonal covariance matrices and propose fast approximate deterministic-based algorithms based on the Variational Bayesian (VB) approach. More specifically, we derive two iterative KF-like algorithms that differ in the way they operate between two successive filtering estimates; one involves a smoothing estimate and the other involves a prediction estimate. Despite its iterative nature, the prediction-based algorithm provides a computational cost that is, on the one hand, independent of the number of iterations in the limit of very large state dimensions, and on the other hand, always much smaller than the cost of the EnKF. The cost of the smoothing-based algorithm depends on the number of iterations that may, in some situations, make this algorithm slower than the EnKF. The performances of the proposed filters are studied and compared to those of the KF and EnKF through a numerical example.

  16. Petri Net Modeling of the Brain Circuit Involved in Aggressive Behavior

    OpenAIRE

    Moreno, Carlos B.; Díaz, José-Luis; Martínez, J. H.

    2015-01-01

    The purpose of this work in to demonstrate the initial results of a research project having as its goal to develop dynamic models of the brain network involved in aggressive behavior. In this way, the complex neural process correlated to basic anger emotions and resulting in aggressive behaviors is purportedly schematized by the use of Petri nets, a work-flow computational tool. Initially, the modeling technique is introduced taking into account the most recent and accepted notion of the neur...

  17. Comparing large-scale computational approaches to epidemic modeling: Agent-based versus structured metapopulation models

    Directory of Open Access Journals (Sweden)

    Merler Stefano

    2010-06-01

    Full Text Available Abstract Background In recent years large-scale computational models for the realistic simulation of epidemic outbreaks have been used with increased frequency. Methodologies adapt to the scale of interest and range from very detailed agent-based models to spatially-structured metapopulation models. One major issue thus concerns to what extent the geotemporal spreading pattern found by different modeling approaches may differ and depend on the different approximations and assumptions used. Methods We provide for the first time a side-by-side comparison of the results obtained with a stochastic agent-based model and a structured metapopulation stochastic model for the progression of a baseline pandemic event in Italy, a large and geographically heterogeneous European country. The agent-based model is based on the explicit representation of the Italian population through highly detailed data on the socio-demographic structure. The metapopulation simulations use the GLobal Epidemic and Mobility (GLEaM model, based on high-resolution census data worldwide, and integrating airline travel flow data with short-range human mobility patterns at the global scale. The model also considers age structure data for Italy. GLEaM and the agent-based models are synchronized in their initial conditions by using the same disease parameterization, and by defining the same importation of infected cases from international travels. Results The results obtained show that both models provide epidemic patterns that are in very good agreement at the granularity levels accessible by both approaches, with differences in peak timing on the order of a few days. The relative difference of the epidemic size depends on the basic reproductive ratio, R0, and on the fact that the metapopulation model consistently yields a larger incidence than the agent-based model, as expected due to the differences in the structure in the intra-population contact pattern of the approaches. The age

  18. Running Large-Scale Air Pollution Models on Parallel Computers

    DEFF Research Database (Denmark)

    Georgiev, K.; Zlatev, Z.

    2000-01-01

    Proceedings of the 23rd NATO/CCMS International Technical Meeting on Air Pollution Modeling and Its Application, held 28 September - 2 October 1998, in Varna, Bulgaria.......Proceedings of the 23rd NATO/CCMS International Technical Meeting on Air Pollution Modeling and Its Application, held 28 September - 2 October 1998, in Varna, Bulgaria....

  19. A Large Scale, High Resolution Agent-Based Insurgency Model

    Science.gov (United States)

    2013-09-30

    2007). HSCB Models can be employed for simulating mission scenarios, determining optimal strategies for disrupting terrorist networks, or training and...High Resolution Agent-Based Insurgency Model ∑ = ⎜ ⎜ ⎝ ⎛ − −− = desired 1 move,desired, desired,,desired, desired,, N j ij jmoveij moveiD rp prp

  20. Misspecified poisson regression models for large-scale registry data

    DEFF Research Database (Denmark)

    Grøn, Randi; Gerds, Thomas A.; Andersen, Per K.

    2016-01-01

    working models that are then likely misspecified. To support and improve conclusions drawn from such models, we discuss methods for sensitivity analysis, for estimation of average exposure effects using aggregated data, and a semi-parametric bootstrap method to obtain robust standard errors. The methods...

  1. Modelling expected train passenger delays on large scale railway networks

    DEFF Research Database (Denmark)

    Landex, Alex; Nielsen, Otto Anker

    2006-01-01

    Forecasts of regularity for railway systems have traditionally – if at all – been computed for trains, not for passengers. Relatively recently it has become possible to model and evaluate the actual passenger delays by a passenger regularity model for the operation already carried out. First...

  2. Predicting Preschoolers' Attachment Security from Fathers' Involvement, Internal Working Models, and Use of Social Support

    Science.gov (United States)

    Newland, Lisa A.; Coyl, Diana D.; Freeman, Harry

    2008-01-01

    Associations between preschoolers' attachment security, fathers' involvement (i.e. parenting behaviors and consistency) and fathering context (i.e. fathers' internal working models (IWMs) and use of social support) were examined in a subsample of 102 fathers, taken from a larger sample of 235 culturally diverse US families. The authors predicted…

  3. Helpful Components Involved in the Cognitive-Experiential Model of Dream Work

    Science.gov (United States)

    Tien, Hsiu-Lan Shelley; Chen, Shuh-Chi; Lin, Chia-Huei

    2009-01-01

    The purpose of the study was to examine the helpful components involved in the Hill's cognitive-experiential dream work model. Participants were 27 volunteer clients from colleges and universities in northern and central parts of Taiwan. Each of the clients received 1-2 sessions of dream interpretations. The cognitive-experiential dream work model…

  4. Traffic assignment models in large-scale applications

    DEFF Research Database (Denmark)

    Rasmussen, Thomas Kjær

    on individual behaviour in the model specification, (ii) proposing a method to use disaggregate Revealed Preference (RP) data to estimate utility functions and provide evidence on the value of congestion and the value of reliability, (iii) providing a method to account for individual mis...... of observations of actual behaviour to obtain estimates of the (monetary) value of different travel time components, thereby increasing the behavioural realism of largescale models. vii The generation of choice sets is a vital component in route choice models. This is, however, not a straight-forward task in real...... non-universal choice sets and (ii) flow distribution according to random utility maximisation theory. One model allows distinction between used and unused routes based on the distribution of the random error terms, while the other model allows this distinction by posing restrictions on the costs...

  5. Multilevel method for modeling large-scale networks.

    Energy Technology Data Exchange (ETDEWEB)

    Safro, I. M. (Mathematics and Computer Science)

    2012-02-24

    Understanding the behavior of real complex networks is of great theoretical and practical significance. It includes developing accurate artificial models whose topological properties are similar to the real networks, generating the artificial networks at different scales under special conditions, investigating a network dynamics, reconstructing missing data, predicting network response, detecting anomalies and other tasks. Network generation, reconstruction, and prediction of its future topology are central issues of this field. In this project, we address the questions related to the understanding of the network modeling, investigating its structure and properties, and generating artificial networks. Most of the modern network generation methods are based either on various random graph models (reinforced by a set of properties such as power law distribution of node degrees, graph diameter, and number of triangles) or on the principle of replicating an existing model with elements of randomization such as R-MAT generator and Kronecker product modeling. Hierarchical models operate at different levels of network hierarchy but with the same finest elements of the network. However, in many cases the methods that include randomization and replication elements on the finest relationships between network nodes and modeling that addresses the problem of preserving a set of simplified properties do not fit accurately enough the real networks. Among the unsatisfactory features are numerically inadequate results, non-stability of algorithms on real (artificial) data, that have been tested on artificial (real) data, and incorrect behavior at different scales. One reason is that randomization and replication of existing structures can create conflicts between fine and coarse scales of the real network geometry. Moreover, the randomization and satisfying of some attribute at the same time can abolish those topological attributes that have been undefined or hidden from

  6. A Research Framework for Understanding the Practical Impact of Family Involvement in the Juvenile Justice System: The Juvenile Justice Family Involvement Model.

    Science.gov (United States)

    Walker, Sarah Cusworth; Bishop, Asia S; Pullmann, Michael D; Bauer, Grace

    2015-12-01

    Family involvement is recognized as a critical element of service planning for children's mental health, welfare and education. For the juvenile justice system, however, parents' roles in this system are complex due to youths' legal rights, public safety, a process which can legally position parents as plaintiffs, and a historical legacy of blaming parents for youth indiscretions. Three recent national surveys of juvenile justice-involved parents reveal that the current paradigm elicits feelings of stress, shame and distrust among parents and is likely leading to worse outcomes for youth, families and communities. While research on the impact of family involvement in the justice system is starting to emerge, the field currently has no organizing framework to guide a research agenda, interpret outcomes or translate findings for practitioners. We propose a research framework for family involvement that is informed by a comprehensive review and content analysis of current, published arguments for family involvement in juvenile justice along with a synthesis of family involvement efforts in other child-serving systems. In this model, family involvement is presented as an ascending, ordinal concept beginning with (1) exclusion, and moving toward climates characterized by (2) information-giving, (3) information-eliciting and (4) full, decision-making partnerships. Specific examples of how courts and facilities might align with these levels are described. Further, the model makes predictions for how involvement will impact outcomes at multiple levels with applications for other child-serving systems.

  7. A model for recovery kinetics of aluminum after large strain

    DEFF Research Database (Denmark)

    Yu, Tianbo; Hansen, Niels

    2012-01-01

    A model is suggested to analyze recovery kinetics of heavily deformed aluminum. The model is based on the hardness of isothermal annealed samples before recrystallization takes place, and it can be extrapolated to longer annealing times to factor out the recrystallization component of the hardness...... for conditions where recovery and recrystallization overlap. The model is applied to the isothermal recovery at temperatures between 140 and 220°C of commercial purity aluminum deformed to true strain 5.5. EBSD measurements have been carried out to detect the onset of discontinuous recrystallization. Furthermore...

  8. A devolved model for public involvement in the field of mental health research: case study learning.

    Science.gov (United States)

    Moule, Pam; Davies, Rosie

    2016-12-01

    Patient and public involvement in all aspects of research is espoused and there is a continued interest in understanding its wider impact. Existing investigations have identified both beneficial outcomes and remaining issues. This paper presents the impact of public involvement in one case study led by a mental health charity conducted as part of a larger research project. The case study used a devolved model of working, contracting with service user-led organizations to maximize the benefits of local knowledge on the implementation of personalized budgets, support recruitment and local user-led organizations. To understand the processes and impact of public involvement in a devolved model of working with user-led organizations. Multiple data collection methods were employed throughout 2012. These included interviews with the researchers (n = 10) and research partners (n = 5), observation of two case study meetings and the review of key case study documentation. Analysis was conducted in NVivo10 using a coding framework developed following a literature review. Five key themes emerged from the data; Devolved model, Nature of involvement, Enabling factors, Implementation challenges and Impact. While there were some challenges of implementing the devolved model it is clear that our findings add to the growing understanding of the positive benefits research partners can bring to complex research. A devolved model can support the involvement of user-led organizations in research if there is a clear understanding of the underpinning philosophy and support mechanisms are in place. © 2015 The Authors. Health Expectations Published by John Wiley & Sons Ltd.

  9. CD10 down expression in follicular lymphoma correlates with gastrointestinal lesion involving the stomach and large intestine.

    Science.gov (United States)

    Ohnishi, Nobuhiko; Takata, Katsuyoshi; Miyata-Takata, Tomoko; Sato, Yasuharu; Tari, Akira; Gion, Yuka; Noujima-Harada, Mai; Taniguchi, Kohei; Tabata, Tetsuya; Nagakita, Keina; Omote, Shizuma; Takahata, Hiroyuki; Iwamuro, Masaya; Okada, Hiroyuki; Maeda, Yoshinobu; Yanai, Hiroyuki; Yoshino, Tadashi

    2016-11-01

    Follicular lymphoma (FL) shows co-expression of B-cell lymphoma 2 (BCL2) and CD10, whereas downexpression of CD10 is occasionally experienced in gastrointestinal (GI) FL with unknown significance. Gastrointestinal FL is a rare variant of FL, and its similarity with mucosa-associated lymphoid tissue lymphoma was reported. We investigated the clinicopathological and genetic features of CD10 downexpressed (CD10(down) ) GI-FL. The diagnosis of CD10(down) FL was carried out with a combination of pathological and molecular analyses. The incidence of CD10(down) GI-FL was shown in 35/172 (20.3%) cases, which was more frequent than nodal FL (3.5%, P stomach or large intestine (P = 0.015), and additionally showed the downexpression of BCL6 (P < 0.001). The follicular dendritic cell meshwork often showed a duodenal pattern in the CD10(down) group (P = 0.12). Furthermore, a lymphoepithelial lesion was observed in 5/12 (40%) gastric FL cases, which indicated caution in the differentiation of mucosa-associated lymphoid tissue lymphoma. Molecular analyses were undertaken in seven cases of CD10(down) GI-FL, and an identical clone was found between CD10(down) follicles and CD10(+) BCL2(+) neoplastic follicles. In the diagnosis of cases with CD10(down) BCL2(+) follicles, careful examination with molecular studies should be carried out. © 2016 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

  10. A Large Deformation Model for the Elastic Moduli of Two-dimensional Cellular Materials

    Institute of Scientific and Technical Information of China (English)

    HU Guoming; WAN Hui; ZHANG Youlin; BAO Wujun

    2006-01-01

    We developed a large deformation model for predicting the elastic moduli of two-dimensional cellular materials. This large deformation model was based on the large deflection of the inclined members of the cells of cellular materials. The deflection of the inclined member, the strain of the representative structure and the elastic moduli of two-dimensional cellular materials were expressed using incomplete elliptic integrals. The experimental results show that these elastic moduli are no longer constant at large deformation, but vary significantly with the strain. A comparison was made between this large deformation model and the small deformation model proposed by Gibson and Ashby.

  11. Exploring model based engineering for large telescopes: getting started with descriptive models

    Science.gov (United States)

    Karban, R.; Zamparelli, M.; Bauvir, B.; Koehler, B.; Noethe, L.; Balestra, A.

    2008-07-01

    Large telescopes pose a continuous challenge to systems engineering due to their complexity in terms of requirements, operational modes, long duty lifetime, interfaces and number of components. A multitude of decisions must be taken throughout the life cycle of a new system, and a prime means of coping with complexity and uncertainty is using models as one decision aid. The potential of descriptive models based on the OMG Systems Modeling Language (OMG SysMLTM) is examined in different areas: building a comprehensive model serves as the basis for subsequent activities of soliciting and review for requirements, analysis and design alike. Furthermore a model is an effective communication instrument against misinterpretation pitfalls which are typical of cross disciplinary activities when using natural language only or free-format diagrams. Modeling the essential characteristics of the system, like interfaces, system structure and its behavior, are important system level issues which are addressed. Also shown is how to use a model as an analysis tool to describe the relationships among disturbances, opto-mechanical effects and control decisions and to refine the control use cases. Considerations on the scalability of the model structure and organization, its impact on the development process, the relation to document-centric structures, style and usage guidelines and the required tool chain are presented.

  12. A Fractal Model for the Shear Behaviour of Large-Scale Opened Rock Joints

    Science.gov (United States)

    Li, Y.; Oh, J.; Mitra, R.; Canbulat, I.

    2017-01-01

    This paper presents a joint constitutive model that represents the shear behaviour of a large-scale opened rock joint. Evaluation of the degree of opening is made by considering the ratio between the joint wall aperture and the joint amplitude. Scale dependence of the surface roughness is investigated by approximating a natural joint profile to a fractal curve patterned in self-affinity. Developed scaling laws show the slopes of critical waviness and critical unevenness tend to flatten with increased sampling length. Geometrical examination of four 400-mm joint profiles agrees well with the suggested formulations involving multi-order asperities and fractal descriptors. Additionally, a fractal-based formulation is proposed to estimate the peak shear displacements of rock joints at varying scales, which shows a good correlation with experimental data taken from the literature. Parameters involved in the constitutive law can be acquired by inspecting roughness features of sampled rock joints. Thus, the model can be implemented in numerical software for the stability analysis of the rock mass with opened joints.

  13. Use of models in large-area forest surveys: comparing model-assisted, model-based and hybrid estimation

    Directory of Open Access Journals (Sweden)

    Göran Ståhl

    2016-02-01

    Full Text Available This paper focuses on the use of models for increasing the precision of estimators in large-area forest surveys. It is motivated by the increasing availability of remotely sensed data, which facilitates the development of models predicting the variables of interest in forest surveys. We present, review and compare three different estimation frameworks where models play a core role: model-assisted, model-based, and hybrid estimation. The first two are well known, whereas the third has only recently been introduced in forest surveys. Hybrid inference mixes designbased and model-based inference, since it relies on a probability sample of auxiliary data and a model predicting the target variable from the auxiliary data..We review studies on large-area forest surveys based on model-assisted, modelbased, and hybrid estimation, and discuss advantages and disadvantages of the approaches. We conclude that no general recommendations can be made about whether model-assisted, model-based, or hybrid estimation should be preferred. The choice depends on the objective of the survey and the possibilities to acquire appropriate field and remotely sensed data. We also conclude that modelling approaches can only be successfully applied for estimating target variables such as growing stock volume or biomass, which are adequately related to commonly available remotely sensed data, and thus purely field based surveys remain important for several important forest parameters. Keywords: Design-based inference, Model-assisted estimation, Model-based inference, Hybrid inference, National forest inventory, Remote sensing, Sampling

  14. Geometric modeling and analysis of large latticed surfaces

    Science.gov (United States)

    Nayfeh, A. H.; Hefzy, M. S.

    1980-01-01

    The application of geometrical schemes, similar to geodesic domes, to large spherical antenna reflectors was investigated. The shape and size of flat segmented latticed surfaces which approximate general shells of revolution, and in particular spherical and paraboloidal reflective surfaces, were determined. The extensive mathematical and computational geometric analyses of the reflector resulted in the development of a general purpose computer program capable of generating the complete design parameters of the dish. The program also includes a graphical self contained subroutine for graphic display of the required design.

  15. Large dimension forecasting models and random singular value spectra

    CERN Document Server

    Bouchaud, J P; Miceli, M A; Potters, M; Bouchaud, Jean-Philippe; Laloux, Laurent; Potters, Marc

    2005-01-01

    We present a general method to detect and extract from a finite time sample statistically meaningful correlations between input and output variables of large dimensionality. Our central result is derived from the theory of free random matrices, and gives an explicit expression for the interval where singular values are expected in the absence of any true correlations between the variables under study. Our result can be seen as the natural generalization of the Marcenko-Pastur distribution for the case of rectangular correlation matrices. We illustrate the interest of our method on a set of macroeconomic time series.

  16. Adaptive optics sky coverage modeling for extremely large telescopes.

    Science.gov (United States)

    Clare, Richard M; Ellerbroek, Brent L; Herriot, Glen; Véran, Jean-Pierre

    2006-12-10

    A Monte Carlo sky coverage model for laser guide star adaptive optics systems was proposed by Clare and Ellerbroek [J. Opt. Soc. Am. A 23, 418 (2006)]. We refine the model to include (i) natural guide star (NGS) statistics using published star count models, (ii) noise on the NGS measurements, (iii) the effect of telescope wind shake, (iv) a model for how the Strehl and hence NGS wavefront sensor measurement noise varies across the field, (v) the focus error due to imperfectly tracking the range to the sodium layer, (vi) the mechanical bandwidths of the tip-tilt (TT) stage and deformable mirror actuators, and (vii) temporal filtering of the NGS measurements to balance errors due to noise and servo lag. From this model, we are able to generate a TT error budget for the Thirty Meter Telescope facility narrow-field infrared adaptive optics system (NFIRAOS) and perform several design trade studies. With the current NFIRAOS design, the median TT error at the galactic pole with median seeing is calculated to be 65 nm or 1.8 mas rms.

  17. Stochastic analysis and modeling of abnormally large waves

    Science.gov (United States)

    Kuznetsov, Konstantin; Shamin, Roman; Yudin, Aleksandr

    2016-04-01

    In this work stochastics of amplitude characteristics of waves during the freak waves formation was estimated. Also amplitude characteristics of freak wave was modeling with the help of the developed Markov model on the basis of in-situ and numerical experiments. Simulation using the Markov model showed a great similarity of results of in-situ wave measurements[1], results of directly calculating the Euler equations[2] and stochastic modeling data. This work is supported by grant of Russian Foundation for Basic Research (RFBR) n°16-35-00526. 1. K. I. Kuznetsov, A. A. Kurkin, E. N. Pelinovsky and P. D. Kovalev Features of Wind Waves at the Southeastern Coast of Sakhalin according to Bottom Pressure Measurements //Izvestiya, Atmospheric and Oceanic Physics, 2014, Vol. 50, No. 2, pp. 213-220. DOI: 10.1134/S0001433814020066. 2. R.V. Shamin, V.E. Zakharov, A.I. Dyachenko. How probability for freak wave formation can be found // THE EUROPEAN PHYSICAL JOURNAL - SPECIAL TOPICS Volume 185, Number 1, 113-124, DOI: 10.1140/epjst/e2010-01242-y 3.E. N. Pelinovsky, K. I. Kuznetsov, J. Touboul, A. A. Kurkin Bottom pressure caused by passage of a solitary wave within the strongly nonlinear Green-Naghdi model //Doklady Physics, April 2015, Volume 60, Issue 4, pp 171-174. DOI: 10.1134/S1028335815040035

  18. Selection Model of Optional Parts in Suppliers Involved in New Product Development

    Institute of Scientific and Technical Information of China (English)

    MU Lifeng; TANG Jiafu; PAN Zhendong; HAN Yi

    2006-01-01

    Quality function deployment (QFD), which can translate efficiently customer requirement (CRs) into technical attributes (TAs), is widely used in new product development (NPD) as an efficient customer-driven approach. After lots of QFD application is applied in manufacturing fields, it was proved that without considering suppliers involved, it is difficult to get precise and satisfying results in each process of QFD, particularly part deployment. The paper will address the issues of a model of optional parts selection in suppliers involved in part deployment process. Further, it has been applied to an ERP system reconstruction and updating problem as an illustration.

  19. Sediment Yield Modeling in a Large Scale Drainage Basin

    Science.gov (United States)

    Ali, K.; de Boer, D. H.

    2009-05-01

    This paper presents the findings of spatially distributed sediment yield modeling in the upper Indus River basin. Spatial erosion rates calculated by using the Thornes model at 1-kilometre spatial resolution and monthly time scale indicate that 87 % of the annual gross erosion takes place in the three summer months. The model predicts a total annual erosion rate of 868 million tons, which is approximately 4.5 times the long- term observed annual sediment yield of the basin. Sediment delivery ratios (SDR) are hypothesized to be a function of the travel time of surface runoff from catchment cells to the nearest downstream channel. Model results indicate that higher delivery ratios (SDR > 0.6) are found in 18 % of the basin area, mostly located in the high-relief sub-basins and in the areas around the Nanga Parbat Massif. The sediment delivery ratio is lower than 0.2 in 70 % of the basin area, predominantly in the low-relief sub-basins like the Shyok on the Tibetan Plateau. The predicted annual basin sediment yield is 244 million tons which compares reasonably to the measured value of 192.5 million tons. The average annual specific sediment yield in the basin is predicted as 1110 tons per square kilometre. Model evaluation based on accuracy statistics shows very good to satisfactory performance ratings for predicted monthly basin sediment yields and for mean annual sediment yields of 17 sub-basins. This modeling framework mainly requires global datasets, and hence can be used to predict erosion and sediment yield in other ungauged drainage basins.

  20. Hierarchical Bayesian spatial models for predicting multiple forest variables using waveform LiDAR, hyperspectral imagery, and large inventory datasets

    Science.gov (United States)

    Finley, Andrew O.; Banerjee, Sudipto; Cook, Bruce D.; Bradford, John B.

    2013-01-01

    In this paper we detail a multivariate spatial regression model that couples LiDAR, hyperspectral and forest inventory data to predict forest outcome variables at a high spatial resolution. The proposed model is used to analyze forest inventory data collected on the US Forest Service Penobscot Experimental Forest (PEF), ME, USA. In addition to helping meet the regression model's assumptions, results from the PEF analysis suggest that the addition of multivariate spatial random effects improves model fit and predictive ability, compared with two commonly applied modeling approaches. This improvement results from explicitly modeling the covariation among forest outcome variables and spatial dependence among observations through the random effects. Direct application of such multivariate models to even moderately large datasets is often computationally infeasible because of cubic order matrix algorithms involved in estimation. We apply a spatial dimension reduction technique to help overcome this computational hurdle without sacrificing richness in modeling.

  1. Dynamic Modeling, Optimization, and Advanced Control for Large Scale Biorefineries

    DEFF Research Database (Denmark)

    Prunescu, Remus Mihail

    with building a plantwide model-based optimization layer, which searches for optimal values regarding the pretreatment temperature, enzyme dosage in liquefaction, and yeast seed in fermentation such that profit is maximized [7]. When biomass is pretreated, by-products are also created that affect the downstream...... processes acting as inhibitors in enzymatic hydrolysis and fermentation. Therefore, the biorefinery is treated in an integrated manner capturing the trade-offs between the conversion steps. Sensitivity and uncertainty analysis is also performed in order to identify the modeling bottlenecks and which...

  2. INTEGRATED STRATEGIES FOR THE MODELING VERY LARGE AND COMPLEX ARCHITECTURES

    Directory of Open Access Journals (Sweden)

    F. Fassi

    2012-09-01

    Full Text Available The paper would like to present a research job conducted in cooperation with the Veneranda Fabbrica of Milan Cathedral to survey and model the main cathedral spire. The job aims to find methods and a typological way to operate to produce an accurate 3D model to support forthcoming restoration works. The paper will concentrate on the description and analysis of problems and difficulties found during the survey processes and solutions chosen to overcome these problems, both in the measuring phase but in particular in the processing one. Future research is also proposed.

  3. REPORT ON THE MODELING OF THE LARGE MIS CANS

    Energy Technology Data Exchange (ETDEWEB)

    E. MOODY; J. LYMAN; K. VEIRS

    2000-12-01

    Changes in gas composition and gas pressure for closed systems containing plutonium dioxide and water are studied using a model that incorporates both radiolysis and chemical reactions. The model is used to investigate the behavior of material stored in storage containers conforming to DOE-STD-3013-99 storage standard. Scaling of the container to allow use of smaller amounts of nuclear material in experiments designed to bound the behavior of all material destined for long-term storage is studied. It is found that the container volume must be scaled along with the amount of material to achieve applicable results.

  4. Modeling and analysis of a large deployable antenna structure

    Science.gov (United States)

    Chu, Zhengrong; Deng, Zongquan; Qi, Xiaozhi; Li, Bing

    2014-02-01

    One kind of large deployable antenna (LDA) structure is proposed by combining a number of basic deployable units in this paper. In order to avoid vibration caused by fast deployment speed of the mechanism, a braking system is used to control the spring-actuated system. Comparisons between the LDA structure and a similar structure used by the large deployable reflector (LDR) indicate that the former has potential for use in antennas with up to 30 m aperture due to its lighter weight. The LDA structure is designed to form a spherical surface found by the least square fitting method so that it can be symmetrical. In this case, the positions of the terminal points in the structure are determined by two principles. A method to calculate the cable network stretched on the LDA structure is developed, which combines the original force density method and the parabolic surface constraint. Genetic algorithm is applied to ensure that each cable reaches a desired tension, which avoids the non-convergence issue effectively. We find that the pattern for the front and rear cable net must be the same when finding the shape of the rear cable net, otherwise anticlastic surface would generate.

  5. Enhanced ICP for the Registration of Large-Scale 3D Environment Models: An Experimental Study.

    Science.gov (United States)

    Han, Jianda; Yin, Peng; He, Yuqing; Gu, Feng

    2016-02-15

    One of the main applications of mobile robots is the large-scale perception of the outdoor environment. One of the main challenges of this application is fusing environmental data obtained by multiple robots, especially heterogeneous robots. This paper proposes an enhanced iterative closest point (ICP) method for the fast and accurate registration of 3D environmental models. First, a hierarchical searching scheme is combined with the octree-based ICP algorithm. Second, an early-warning mechanism is used to perceive the local minimum problem. Third, a heuristic escape scheme based on sampled potential transformation vectors is used to avoid local minima and achieve optimal registration. Experiments involving one unmanned aerial vehicle and one unmanned surface vehicle were conducted to verify the proposed technique. The experimental results were compared with those of normal ICP registration algorithms to demonstrate the superior performance of the proposed method.

  6. Economic Model Predictive Control for Large-Scale and Distributed Energy Systems

    DEFF Research Database (Denmark)

    Standardi, Laura

    . Energy systems often involve stochastic variables due to the share of fluctuating Renewable Energy Sources (RESs). Moreover, the related control problems are multi variables and they are hard, or impossible, to split into single-input-single-output control systems. MPC strategy can handle multi variables......In this thesis, we consider control strategies for large and distributed energy systems that are important for the implementation of smart grid technologies.  An electrical grid has to ensure reliability and avoid long-term interruptions in the power supply. Moreover, the share of Renewable Energy...... Sources (RESs) in the smart grids is increasing. These energy sources bring uncertainty to the production due to their fluctuations. Hence,smart grids need suitable control systems that are able to continuously balance power production and consumption.  We apply the Economic Model Predictive Control (EMPC...

  7. Enhanced ICP for the Registration of Large-Scale 3D Environment Models: An Experimental Study

    Directory of Open Access Journals (Sweden)

    Jianda Han

    2016-02-01

    Full Text Available One of the main applications of mobile robots is the large-scale perception of the outdoor environment. One of the main challenges of this application is fusing environmental data obtained by multiple robots, especially heterogeneous robots. This paper proposes an enhanced iterative closest point (ICP method for the fast and accurate registration of 3D environmental models. First, a hierarchical searching scheme is combined with the octree-based ICP algorithm. Second, an early-warning mechanism is used to perceive the local minimum problem. Third, a heuristic escape scheme based on sampled potential transformation vectors is used to avoid local minima and achieve optimal registration. Experiments involving one unmanned aerial vehicle and one unmanned surface vehicle were conducted to verify the proposed technique. The experimental results were compared with those of normal ICP registration algorithms to demonstrate the superior performance of the proposed method.

  8. Large-scale analysis of the genes involved in fin regeneration and blastema formation in the medaka, Oryzias latipes.

    Science.gov (United States)

    Katogi, Rei; Nakatani, Yuki; Shin-i, Tadasu; Kohara, Yuji; Inohaya, Keiji; Kudo, Akira

    2004-07-01

    Medaka is an attractive model to study epimorphic regeneration. The fins have remarkable regenerative capacity and are replaced about 14 days after amputation. The formation of blastema, a mass of undifferentiated cells, is essential for regeneration; however, the molecular mechanisms are incompletely defined. To identify the genes required for fin regeneration, especially for blastema formation, we constructed cDNA libraries from fin regenerates at 3 days postamputation and 10 days postamputation. A total of 16,866 expression sequence tags (ESTs) were sequenced and subjected to BLASTX analysis. The result revealed that about 60% of them showed strong matches to previously identified proteins, and major signaling molecules related to development, including FGF, BMP, Wnt, Notch/Delta, and Ephrin/Eph signaling pathways were isolated. To identify novel genes that showed specific expression during fin regeneration, cDNA microarray was generated based on 2900 independent ESTs from each library which had no sequence similarity to known proteins. We obtained 6 candidate genes associated with blastema formation by gene expression pattern screening in competitive hybridization analyses and in situ hybridization. Olrfe16d23 and olrfe14k04 were expressed only in early regenerating stages when blastema formation was induced. The expression of olrf5n23, which encodes a novel signal peptide, was detected in wound epidermis throughout regeneration. Olrfe23l22, olrfe20n22, and olrfe24i02 were expressed notably in the blastema region. Our study has thus identified the gene expression profiles and some novel candidate genes to facilitate elucidation of the molecular mechanisms of fin regeneration.

  9. A model for presenting accelerometer paradata in large studies: ISCOLE

    OpenAIRE

    Tudor-Locke, Catrine; Mire, Emily F; Dentro, Kara N; Barreira, Tiago V.; Schuna, John M.; Zhao, Pei; Tremblay, Mark S; Standage, Martyn; Sarmiento, Olga L.; Onywera, Vincent; Olds, Tim; Matsudo, Victor; Maia, José; Maher, Carol; Estelle V. Lambert

    2015-01-01

    Abstract Background We present a model for reporting accelerometer paradata (process-related data produced from survey administration) collected in the International Study of Childhood Obesity Lifestyle and the Environment (ISCOLE), a multi-national investigation of >7000 children (averaging 10.5 years of age) sampled from 12 different developed and developing countries and five continents. ...

  10. Modeling Fermi Large Area Telescope and Multiwavelength Data from Blazars

    CERN Document Server

    Finke, Justin

    2016-01-01

    Blazars are active galactic nuclei with relativistic jets pointed at the Earth, making them extremely bright at essentially all wavelengths, from radio to gamma rays. I review the modeling of this broadband spectral energy distributions of these objects, and what we have learned, with a focus on gamma rays.

  11. Predictability of the large relaxations in a cellular automaton model

    Energy Technology Data Exchange (ETDEWEB)

    Tejedor, Alejandro; Ambroj, Samuel; Gomez, Javier B; Pacheco, Amalio F [Faculty of Sciences, University of Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza (Spain)

    2008-09-19

    A simple one-dimensional cellular automaton model with threshold dynamics is introduced. It is loaded at a uniform rate and unloaded by abrupt relaxations. The cumulative distribution of the size of the relaxations is analytically computed and behaves as a power law with an exponent equal to -1. This coincides with the phenomenological Gutenberg-Richter behavior observed in seismology for the cumulative statistics of earthquakes at the regional or global scale. The key point of the model is the zero-load state of the system after the occurrence of any relaxation, no matter what its size. This leads to an equipartition of probability between all possible load configurations in the system during the successive loading cycles. Each cycle ends with the occurrence of the greatest-or characteristic-relaxation in the system. The duration of the cycles in the model is statistically distributed with a coefficient of variation ranging from 0.5 to 1. The predictability of the characteristic relaxations is evaluated by means of error diagrams. This model illustrates the value taking into account the refractory periods to obtain a considerable gain in the quality of the predictions.

  12. Large BR(h -> tau mu) in Supersymmetric Models

    CERN Document Server

    Hammad, Ahmed; Un, Cem Salih

    2016-01-01

    We analyze the Lepton Flavor Violating (LFV) Higgs decay h -> tau mu in three supersymmetric models: Minimal Supersymmetric Standard Model (MSSM), Supersymmetric Seesaw Model (SSM), and Supersymmetric B-L model with Inverse Seesaw (BLSSM-IS). We show that in generic MSSM, with non-universal slepton masses and/or trilinear couplings, it is not possible to enhance BR(h -> tau mu) without violating the experimental bound on the BR(tau -> mu gamma). In SSM, where flavor mixing is radiatively generated, the LFV process mu -> e gamma strictly constrains the parameter space and the maximum value of BR(h -> tau mu) is of order 10^-10, which is extremely smaller than the recent results reported by the CMS and ATLAS experiments. In BLSSM-IS, with universal soft SUSY breaking terms at the grand unified scale, we emphasize that the measured values of BR(h -> tau mu) can be accommodated in a wide region of parameter space without violating LFV constraints. Thus, confirming the LFV Higgs decay results will be a clear signa...

  13. Optimisation of a large WWTP thanks to mathematical modelling.

    Science.gov (United States)

    Printemps, C; Baudin, A; Dormoy, T; Zug, M; Vanrolleghem, P A

    2004-01-01

    Better controlling and optimising the plant's processes has become a priority for WWTP (Wastewater Treatment Plant) managers. The main objective of this project is to develop a simplified mathematical tool able to reproduce and anticipate the behaviour of the Tougas WWTP (Nantes, France). This tool is aimed to be used directly by the managers of the site. The mathematical WWTP model was created using the software WEST. This paper describes the studied site and the modelling results obtained during the stage of the model calibration and validation. The good simulation results have allowed to show that despite a first very simple description of the WWTP, the model was able to correctly predict the nitrogen composition (ammonia and nitrate) of the effluent and the daily sludge extraction. Then, a second more detailed configuration of the WWTP was implemented. It has allowed to independently study the behaviour of each of four biological trains. Once this first stage will be completely achieved, the remainder of the study will focus on the operational use of a simplified simulator with the purpose of optimising the Tougas WWTP operation.

  14. Models of 'obesity' in large animals and birds.

    Science.gov (United States)

    Clarke, Iain J

    2008-01-01

    Most laboratory-based research on obesity is carried out in rodents, but there are a number of other interesting models in the animal kingdom that are instructive. This includes domesticated animal species such as pigs and sheep, as well as wild, migrating and hibernating species. Larger animals allow particular experimental manipulations that are not possible in smaller animals and especially useful models have been developed to address issues such as manipulation of fetal development. Although some of the most well-studied models are ruminants, with metabolic control that differs from monogastrics, the general principles of metabolic regulation still pertain. It is possible to obtain much more accurate endocrine profiles in larger animals and this has provided important data in relation to leptin and ghrelin physiology. Genetic models have been created in domesticated animals through selection and these complement those of the laboratory rodent. This short review highlights particular areas of research in domesticated and wild species that expand our knowledge of systems that are important for our understanding of obesity and metabolism.

  15. Coupled hydrogeological and geomechanical modelling for the analysis of large slope instabilities.

    Science.gov (United States)

    Laloui, Lyesse; Ferrari, Alessio; Bonnard, Christophe

    2010-05-01

    Slowly-moving landslides (average velocity between 2 and 10 cm/year) are quite frequent in mountainous or hilly areas and they may display occasional crises, generally due to exceptional climatic conditions. The hazard related to these events cannot be analysed in terms of probability analysis, as the number of recorded past events is generally very small and climate changes could significantly modify the environmental setting. Quantitative relationships relating climatic condition fluctuations and sliding area velocity must then be pursued by taking into account the most relevant physical processes involved in the landslide behaviours. Conventional stability analyses are unable to deal with such questions because they do not allow the velocity fields to be determined. With regard to the behaviour of large slope instabilities, a methodology is presented which aims to describe the behaviour of slow-moving landslides by means of a coupled hydrogeological and geomechanical modelling framework. As it is well known, the evolution of the pore water pressure within the landslide body is often recognized as the main cause for the occurrence of displacement accelerations. In this sense the interaction among the hydrological and the mechanical responses must be considered to analyse the landslide behaviour, with the aim of quantitatively relating pore water pressure variations and movements. For a given case study, pore water pressure evolutions in space and time are obtained from a duly calibrated finite element hydrogeological model, which can take into account the role of several key factors such as infiltration, preferential flows and vegetation. Computed groundwater pressures resulting from the hydrogeological simulations are introduced as nodal forces in a finite element geomechanical model in order to calculate stress evolutions and displacements. The use of advanced constitutive models based on the generalised effective stress concept allows taking into account

  16. Large Deviation Results for Generalized Compound Negative Binomial Risk Models

    Institute of Scientific and Technical Information of China (English)

    Fan-chao Kong; Chen Shen

    2009-01-01

    In this paper we extend and improve some results of the large deviation for random sums of random variables.Let {Xn;n≥1} be a sequence of non-negative,independent and identically distributed random variables with common heavy-tailed distribution function F and finite mean μ∈R+,{N(n);n≥0} be a sequence of negative binomial distributed random variables with a parameter p ∈(0,1),n≥0,let {M(n);n≥0} be a Poisson process with intensity λ0.Suppose {N(n);n≥0},{Xn;n≥1} and {M(n);n≥0} are mutually results.These results can be applied to certain problems in insurance and finance.

  17. Opioid receptor types involved in the development of nicotine physical dependence in an invertebrate (Planaria) model.

    Science.gov (United States)

    Raffa, Robert B; Baron, Steve; Bhandal, Jaspreet S; Brown, Tevin; Song, Kevin; Tallarida, Christopher S; Rawls, Scott M

    2013-11-01

    Recent data suggest that opioid receptors are involved in the development of nicotine physical dependence in mammals. Evidence in support of a similar involvement in an invertebrate (Planaria) is presented using the selective opioid receptor antagonist naloxone, and the more receptor subtype-selective antagonists CTAP (D-Phe-Cys-Tyr-D-Trp-Arg-Thr-Pen-Thr-NH2) (μ, MOR), naltrindole (δ, DOR), and nor-BNI (norbinaltorphimine) (κ, KOR). Induction of physical dependence was achieved by 60-min pre-exposure of planarians to nicotine and was quantified by abstinence-induced withdrawal (reduction in spontaneous locomotor activity). Known MOR and DOR subtype-selective opioid receptor antagonists attenuated the withdrawal, as did the non-selective antagonist naloxone, but a KOR subtype-selective antagonist did not. An involvement of MOR and DOR, but not KOR, in the development of nicotine physical dependence or in abstinence-induced withdrawal was thus demonstrated in a sensitive and facile invertebrate model.

  18. A homology model of Xyloglucan Xylosyltransferase 2 reveals critical amino acids involved in substrate binding.

    Science.gov (United States)

    Culbertson, Alan T; Tietze, Alesia A; Tietze, Daniel; Chou, Yi-Hsiang; Smith, Adrienne L; Young, Zachary T; Zabotina, Olga A

    2016-09-01

    In dicotyledonous plants, xyloglucan (XyG) is the most abundant hemicellulose of the primary cell wall. The enzymes involved in XyG biosynthesis have been identified through reverse-genetics and activity was characterized by heterologous expression. Currently, there is no information on the atomic structures or amino acids involved in activity or substrate binding of any of the Golgi-localized XyG biosynthetic enzymes. A homology model of the xyloglucan xylosyltransferase 2 (XXT2) catalytic domain was built on the basis of the crystal structure of A64Rp. Molecular dynamics simulations revealed that the homology model retains the glycosyltransferase (GT)-A fold of the template structure used to build the homology model indicating that XXT2 likely has a GT-A fold. According to the XXT2 homology model, six amino acids (Phe204, Lys207, Asp228, Ser229, Asp230, His378) were selected and their contribution in catalytic activity was investigated. Site-directed mutagenesis studies show that Asp228, Asp230 and His378 are critical for XXT2 activity and are predicted to be involved in coordination of manganese ion. Lys207 was also found to be critical for protein activity and the homology model indicates a critical role in substrate binding. Additionally, Phe204 mutants have less of an impact on XXT2 activity with the largest effect when replaced with a polar residue. This is the first study that investigates the amino acids involved in substrate binding of the XyG-synthesizing xylosyltransferases and contributes to the understanding of the mechanisms of polysaccharide-synthesizing GTs and XyG biosynthesis. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  19. Evaluation of vehicle damage involved in road crashes based on quantificated model

    Institute of Scientific and Technical Information of China (English)

    FAN Yan-hui; XU Hong-guo; JIANG Hua-ping

    2008-01-01

    Based on economics theory, social value loss caused by vehicle involved in crashes as well as various factors influencing on it were analyzed, the corresponding micro-econometrics model was theoretically given. Moreover, the practicability of the model,the veracity and rationality of quantification were analyzed. Based on probability theory and mathematical statistical theory, macro approach to evaluating vehicle damage in crashes was presented, and the corresponding macro-econometrics model was constructed. In addition, the macro-econometrics model was utilized to assess economic loss from statistical data of vehicle damaged in crashes, which has shown that the model can meet the demand of quantification analysis of vehicle damage, and be applied to the evaluation of economic loss caused by crashes. The results in this paper will be of practical significance for scientific, comprehensive and rational evaluating socio-economic loss caused by road crashes.

  20. Uncertainty Quantification for Large-Scale Ice Sheet Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Ghattas, Omar [Univ. of Texas, Austin, TX (United States)

    2016-02-05

    This report summarizes our work to develop advanced forward and inverse solvers and uncertainty quantification capabilities for a nonlinear 3D full Stokes continental-scale ice sheet flow model. The components include: (1) forward solver: a new state-of-the-art parallel adaptive scalable high-order-accurate mass-conservative Newton-based 3D nonlinear full Stokes ice sheet flow simulator; (2) inverse solver: a new adjoint-based inexact Newton method for solution of deterministic inverse problems governed by the above 3D nonlinear full Stokes ice flow model; and (3) uncertainty quantification: a novel Hessian-based Bayesian method for quantifying uncertainties in the inverse ice sheet flow solution and propagating them forward into predictions of quantities of interest such as ice mass flux to the ocean.

  1. A noise generation and propagation model for large wind farms

    DEFF Research Database (Denmark)

    Bertagnolio, Franck

    2016-01-01

    A wind turbine noise calculation model is combined with a ray tracing method in order to estimate wind farm noise in its surrounding assuming an arbitrary topography. The wind turbine noise model is used to generate noise spectra for which each turbine is approximated as a point source. However......, the detailed three-dimensional directivity features are taken into account for the further calculation of noise propagation over the surrounding terrain. An arbitrary number of turbines constituting a wind farm can be spatially distributed. The noise from each individual turbine is propagated into the far......-field using the ray tracing method. These results are added up assuming the noise from each turbine is uncorrelated. The methodology permits to estimate a wind farm noise map over the surrounding terrain in a reasonable amount of computational time on a personal computer....

  2. Disease Modeling via Large-Scale Network Analysis

    Science.gov (United States)

    2015-05-20

    enzymes, ion channels , G- protein-coupled receptors, and nuclear receptors). Our methods incorporate information from eight other model organisms, namely...specific genes to traits and diseases , especially polygenic traits, which are the most challenging. We are also interested in developing theoretical...plant traits relevant to desirable agricultural properties to important human diseases . Our methods, Katz on 1. REPORT DATE (DD-MM-YYYY) 4. TITLE AND

  3. A better large $N$ expansion for chiral Yukawa models

    CERN Document Server

    Bathas, G; Bathas, George; Neuberger, Herbert

    1992-01-01

    We consider the most general renormalizable chiral Yukawa model with $SU(3)_{\\rm color}$ replaced by $SU(N_c)$, $SU(2)_{\\rm L}$ replaced by $SU(N_w )$ and $U(1)_{Y}$ replaced by $U(1)^{N_w -1}$ in the limit $N_c \\rightarrow\\infty$, $N_w \\rightarrow\\infty$ with the ratio $\\rho=\\sqrt{{N_w}\\over{N_c}} \

  4. Confocal microscopy-based three-dimensional cell-specific modeling for large deformation analyses in cellular mechanics.

    Science.gov (United States)

    Slomka, Noa; Gefen, Amit

    2010-06-18

    This study introduces a new confocal microscopy-based three-dimensional cell-specific finite element (FE) modeling methodology for simulating cellular mechanics experiments involving large cell deformations. Three-dimensional FE models of undifferentiated skeletal muscle cells were developed by scanning C2C12 myoblasts using a confocal microscope, and then building FE model geometries from the z-stack images. Strain magnitudes and distributions in two cells were studied when the cells were subjected to compression and stretching, which are used in pressure ulcer and deep tissue injury research to induce large cell deformations. Localized plasma membrane and nuclear surface area (NSA) stretches were observed for both the cell compression and stretching simulation configurations. It was found that in order to induce large tensile strains (>5%) in the plasma membrane and NSA, one needs to apply more than approximately 15% of global cell deformation in cell compression tests, or more than approximately 3% of tensile strains in the elastic plate substrate in cell stretching experiments. Utilization of our modeling can substantially enrich experimental cellular mechanics studies in classic cell loading designs that typically involve large cell deformations, such as static and cyclic stretching, cell compression, micropipette aspiration, shear flow and hydrostatic pressure, by providing magnitudes and distributions of the localized cellular strains specific to each setup and cell type, which could then be associated with the applied stimuli.

  5. Modelling artificial sea salt emission in large eddy simulations.

    Science.gov (United States)

    Maalick, Z; Korhonen, H; Kokkola, H; Kühn, T; Romakkaniemi, S

    2014-12-28

    We study the dispersion of sea salt particles from artificially injected sea spray at a cloud-resolving scale. Understanding of how different aerosol processes affect particle dispersion is crucial when designing emission sources for marine cloud brightening. Compared with previous studies, we include for the first time an explicit treatment of aerosol water, which takes into account condensation, evaporation and their effect on ambient temperature. This enables us to capture the negative buoyancy caused by water evaporation from aerosols. Additionally, we use a higher model resolution to capture aerosol loss through coagulation near the source point. We find that, with a seawater flux of 15 kg s(-1), the cooling due to evaporation can be as much as 1.4 K, causing a delay in particle dispersion of 10-20 min. This delay enhances particle scavenging by a factor of 1.14 compared with simulations without aerosol water. We further show that both cooling and particle dispersion depend on the model resolution, with a maximum particle scavenging efficiency of 20% within 5 h after emission at maximum resolution of 50 m. Based on these results, we suggest further regional high-resolution studies which model several injection periods over several weeks.

  6. Modelling artificial sea salt emission in large eddy simulations

    Science.gov (United States)

    Maalick, Z.; Korhonen, H.; Kokkola, H.; Kühn, T.; Romakkaniemi, S.

    2014-01-01

    We study the dispersion of sea salt particles from artificially injected sea spray at a cloud-resolving scale. Understanding of how different aerosol processes affect particle dispersion is crucial when designing emission sources for marine cloud brightening. Compared with previous studies, we include for the first time an explicit treatment of aerosol water, which takes into account condensation, evaporation and their effect on ambient temperature. This enables us to capture the negative buoyancy caused by water evaporation from aerosols. Additionally, we use a higher model resolution to capture aerosol loss through coagulation near the source point. We find that, with a seawater flux of 15 kg s−1, the cooling due to evaporation can be as much as 1.4 K, causing a delay in particle dispersion of 10–20 min. This delay enhances particle scavenging by a factor of 1.14 compared with simulations without aerosol water. We further show that both cooling and particle dispersion depend on the model resolution, with a maximum particle scavenging efficiency of 20% within 5 h after emission at maximum resolution of 50 m. Based on these results, we suggest further regional high-resolution studies which model several injection periods over several weeks. PMID:25404679

  7. Degree of multicollinearity and variables involved in linear dependence in additive-dominant models

    Directory of Open Access Journals (Sweden)

    Juliana Petrini

    2012-12-01

    Full Text Available The objective of this work was to assess the degree of multicollinearity and to identify the variables involved in linear dependence relations in additive-dominant models. Data of birth weight (n=141,567, yearling weight (n=58,124, and scrotal circumference (n=20,371 of Montana Tropical composite cattle were used. Diagnosis of multicollinearity was based on the variance inflation factor (VIF and on the evaluation of the condition indexes and eigenvalues from the correlation matrix among explanatory variables. The first model studied (RM included the fixed effect of dam age class at calving and the covariates associated to the direct and maternal additive and non-additive effects. The second model (R included all the effects of the RM model except the maternal additive effects. Multicollinearity was detected in both models for all traits considered, with VIF values of 1.03 - 70.20 for RM and 1.03 - 60.70 for R. Collinearity increased with the increase of variables in the model and the decrease in the number of observations, and it was classified as weak, with condition index values between 10.00 and 26.77. In general, the variables associated with additive and non-additive effects were involved in multicollinearity, partially due to the natural connection between these covariables as fractions of the biological types in breed composition.

  8. Large-scale groundwater modeling using global datasets: a test case for the Rhine-Meuse basin

    Directory of Open Access Journals (Sweden)

    E. H. Sutanudjaja

    2011-09-01

    Full Text Available The current generation of large-scale hydrological models does not include a groundwater flow component. Large-scale groundwater models, involving aquifers and basins of multiple countries, are still rare mainly due to a lack of hydro-geological data which are usually only available in developed countries. In this study, we propose a novel approach to construct large-scale groundwater models by using global datasets that are readily available. As the test-bed, we use the combined Rhine-Meuse basin that contains groundwater head data used to verify the model output. We start by building a distributed land surface model (30 arc-second resolution to estimate groundwater recharge and river discharge. Subsequently, a MODFLOW transient groundwater model is built and forced by the recharge and surface water levels calculated by the land surface model. Results are promising despite the fact that we still use an offline procedure to couple the land surface and MODFLOW groundwater models (i.e. the simulations of both models are separately performed. The simulated river discharges compare well to the observations. Moreover, based on our sensitivity analysis, in which we run several groundwater model scenarios with various hydro-geological parameter settings, we observe that the model can reasonably well reproduce the observed groundwater head time series. However, we note that there are still some limitations in the current approach, specifically because the offline-coupling technique simplifies the dynamic feedbacks between surface water levels and groundwater heads, and between soil moisture states and groundwater heads. Also the current sensitivity analysis ignores the uncertainty of the land surface model output. Despite these limitations, we argue that the results of the current model show a promise for large-scale groundwater modeling practices, including for data-poor environments and at the global scale.

  9. Portraiture of constructivist parental involvement: A model to develop a community of practice

    Science.gov (United States)

    Dignam, Christopher Anthony

    This qualitative research study addressed the problem of the lack of parental involvement in secondary school science. Increasing parental involvement is vital in supporting student academic achievement and social growth. The purpose of this emergent phenomenological study was to identify conditions required to successfully construct a supportive learning environment to form partnerships between students, parents, and educators. The overall research question in this study investigated the conditions necessary to successfully enlist parental participation with students during science inquiry investigations at the secondary school level. One hundred thirteen pairs of parents and students engaged in a 6-week scientific inquiry activity and recorded attitudinal data in dialogue journals, questionnaires, open-ended surveys, and during one-one-one interviews conducted by the researcher between individual parents and students. Comparisons and cross-interpretations of inter-rater, codified, triangulated data were utilized for identifying emergent themes. Data analysis revealed the active involvement of parents in researching with their child during inquiry investigations, engaging in journaling, and assessing student performance fostered partnerships among students, parents, and educators and supported students' social skills development. The resulting model, employing constructivist leadership and enlisting parent involvement, provides conditions and strategies required to develop a community of practice that can help effect social change. The active involvement of parents fostered improved efficacy and a holistic mindset to develop in parents, students, and teachers. Based on these findings, the interactive collaboration of parents in science learning activities can proactively facilitate a community of practice that will assist educators in facilitating social change.

  10. Context-dependent encoding of fear and extinction memories in a large-scale network model of the basal amygdala.

    OpenAIRE

    Ioannis Vlachos; Cyril Herry; Andreas Lüthi; Ad Aertsen; Arvind Kumar

    2011-01-01

    International audience; The basal nucleus of the amygdala (BA) is involved in the formation of context-dependent conditioned fear and extinction memories. To understand the underlying neural mechanisms we developed a large-scale neuron network model of the BA, composed of excitatory and inhibitory leaky-integrate-and-fire neurons. Excitatory BA neurons received conditioned stimulus (CS)-related input from the adjacent lateral nucleus (LA) and contextual input from the hippocampus or medial pr...

  11. Large meteorite impacts: The K/T model

    Science.gov (United States)

    Bohor, B. F.

    1992-01-01

    The Cretaceous/Tertiary (K/T) boundary event represents probably the largest meteorite impact known on Earth. It is the only impact event conclusively linked to a worldwide mass extinction, a reflection of its gigantic scale and global influence. Until recently, the impact crater was not definitively located and only the distal ejecta of this impact was available for study. However, detailed investigations of this ejecta's mineralogy, geochemistry, microstratigraphy, and textures have allowed its modes of ejection and dispersal to be modeled without benefit of a source crater of known size and location.

  12. Modeling Large Time Series for Efficient Approximate Query Processing

    DEFF Research Database (Denmark)

    Perera, Kasun S; Hahmann, Martin; Lehner, Wolfgang

    2015-01-01

    Evolving customer requirements and increasing competition force business organizations to store increasing amounts of data and query them for information at any given time. Due to the current growth of data volumes, timely extraction of relevant information becomes more and more difficult...... these issues, compression techniques have been introduced in many areas of data processing. In this paper, we outline a new system that does not query complete datasets but instead utilizes models to extract the requested information. For time series data we use Fourier and Cosine transformations and piece...

  13. Model-Switched Beamformer with Large Dynamic Range

    Directory of Open Access Journals (Sweden)

    Zeng Hao

    2014-01-01

    Full Text Available The strong desired signal will be mitigated due to “self-nulling” for the adaptive beamformer, even if the array calibration is used. The proposed methodology switches the models between phased array and adaptive array. In general, the system utilizes Frost adaptive beamforming. However, it will be switched to phased array if the “self-nulling” appears. According to the estimation of the array pattern at the direction of desired signal, we can determine if the “self-nulling” happens. The new approach is much easier to implement compared with the various robust beamforming algorithms.

  14. A Memory Insensitive Technique for Large Model Simplification

    Energy Technology Data Exchange (ETDEWEB)

    Lindstrom, P; Silva, C

    2001-08-07

    In this paper we propose three simple, but significant improvements to the OoCS (Out-of-Core Simplification) algorithm of Lindstrom [20] which increase the quality of approximations and extend the applicability of the algorithm to an even larger class of compute systems. The original OoCS algorithm has memory complexity that depends on the size of the output mesh, but no dependency on the size of the input mesh. That is, it can be used to simplify meshes of arbitrarily large size, but the complexity of the output mesh is limited by the amount of memory available. Our first contribution is a version of OoCS that removes the dependency of having enough memory to hold (even) the simplified mesh. With our new algorithm, the whole process is made essentially independent of the available memory on the host computer. Our new technique uses disk instead of main memory, but it is carefully designed to avoid costly random accesses. Our two other contributions improve the quality of the approximations generated by OoCS. We propose a scheme for preserving surface boundaries which does not use connectivity information, and a scheme for constraining the position of the ''representative vertex'' of a grid cell to an optimal position inside the cell.

  15. Modeling a Large Data Acquisition Network in a Simulation Framework

    CERN Document Server

    Colombo, Tommaso; The ATLAS collaboration

    2015-01-01

    The ATLAS detector at CERN records particle collision “events” delivered by the Large Hadron Collider. Its data-acquisition system is a distributed software system that identifies, selects, and stores interesting events in near real-time, with an aggregate throughput of several 10 GB/s. It is a distributed software system executed on a farm of roughly 2000 commodity worker nodes communicating via TCP/IP on an Ethernet network. Event data fragments are received from the many detector readout channels and are buffered, collected together, analyzed and either stored permanently or discarded. This system, and data-acquisition systems in general, are sensitive to the latency of the data transfer from the readout buffers to the worker nodes. Challenges affecting this transfer include the many-to-one communication pattern and the inherently bursty nature of the traffic. In this paper we introduce the main performance issues brought about by this workload, focusing in particular on the so-called TCP incast pathol...

  16. Flight Dynamics Simulation Modeling and Control of a Large Flexible Tiltrotor Aircraft

    Science.gov (United States)

    2014-09-01

    TECHNICAL REPORT CR-RDMR-AF-14-01 FLIGHT DYNAMICS SIMULATION MODELING AND CONTROL OF A LARGE FLEXIBLE TILTROTOR AIRCRAFT...September 2014 3. REPORT TYPE AND DATES COVERED Final 4. TITLE AND SUBTITLE Flight Dynamics Simulation Modeling and Control of a Large Flexible...18 298-102 i/ii (Blank) FLIGHT DYNAMICS SIMULATION MODELING AND CONTROL OF A LARGE FLEXIBLE TILTROTOR AIRCRAFT by Ondrej Juhasz Dissertation

  17. Involving the elderly in the design process: a participatory design model for usability, safety and attractiveness

    OpenAIRE

    Demirbilek, Oya

    1999-01-01

    Ankara : Institute of Economics and Social Sciences of Bilkent University, 1999. Thesis (Ph.D.) -- Bilkent University, 1999 Includes bibliographical references leaves 113-131 This work presents a conceptual model involving the elderly users into the design process by means of participatory design sessions, where the expertise of designers and the real requirements and opinions of elderly end-users, related to how objects, environments and equipment should be designed to allow ageing ...

  18. Semi-Implicit Algorithm for Elastoplastic Damage Models Involving Energy Integration

    OpenAIRE

    Ji Zhang; Jie Li

    2016-01-01

    This study aims to develop a semi-implicit constitutive integration algorithm for a class of elastoplastic damage models where calculation of damage energy release rates involves integration of free energy. The constitutive equations with energy integration are split into the elastic predictor, plastic corrector, and damage corrector. The plastic corrector is solved with an improved format of the semi-implicit spectral return mapping, which is characterized by constant flow direction and plas...

  19. Development of a Gravid Uterus Model for the Study of Road Accidents Involving Pregnant Women.

    Science.gov (United States)

    Auriault, F; Thollon, L; Behr, M

    2016-01-01

    Car accident simulations involving pregnant women are well documented in the literature and suggest that intra-uterine pressure could be responsible for the phenomenon of placental abruption, underlining the need for a realistic amniotic fluid model, including fluid-structure interactions (FSI). This study reports the development and validation of an amniotic fluid model using an Arbitrary Lagrangian Eulerian formulation in the LS-DYNA environment. Dedicated to the study of the mechanisms responsible for fetal injuries resulting from road accidents, the fluid model was validated using dynamic loading tests. Drop tests were performed on a deformable water-filled container at acceleration levels that would be experienced in a gravid uterus during a frontal car collision at 25 kph. During the test device braking phase, container deformation induced by inertial effects and FSI was recorded by kinematic analysis. These tests were then simulated in the LS-DYNA environment to validate a fluid model under dynamic loading, based on the container deformations. Finally, the coupling between the amniotic fluid model and an existing finite-element full-body pregnant woman model was validated in terms of pressure. To do so, experimental test results performed on four postmortem human surrogates (PMHS) (in which a physical gravid uterus model was inserted) were used. The experimental intra-uterine pressure from these tests was compared to intra uterine pressure from a numerical simulation performed under the same loading conditions. Both free fall numerical and experimental responses appear strongly correlated. The relationship between the amniotic fluid model and pregnant woman model provide intra-uterine pressure values correlated with the experimental test responses. The use of an Arbitrary Lagrangian Eulerian formulation allows the analysis of FSI between the amniotic fluid and the gravid uterus during a road accident involving pregnant women.

  20. Spherical Model on a Cayley Tree: Large Deviations

    Science.gov (United States)

    Patrick, A. E.

    2017-01-01

    We study the spherical model of a ferromagnet on a Cayley tree and show that in the case of empty boundary conditions a ferromagnetic phase transition takes place at the critical temperature T_c =6√{2}/5J, where J is the interaction strength. For any temperature the equilibrium magnetization, m_n, tends to zero in the thermodynamic limit, and the true order parameter is the renormalized magnetization r_n=n^{3/2}m_n, where n is the number of generations in the Cayley tree. Below T_c, the equilibrium values of the order parameter are given by ± ρ ^*, where ρ ^*=2π /(√{2-1)^2}√{1-T/T_c}. One more notable temperature in the model is the penetration temperature T_p=J/W_Cayley(3/2)( 1-1/√{2}( h/2J) ^2) . Below T_p the influence of homogeneous boundary field of magnitude h penetrates throughout the tree. The main new technical result of the paper is a complete set of orthonormal eigenvectors for the discrete Laplace operator on a Cayley tree.

  1. Towards agile large-scale predictive modelling in drug discovery with flow-based programming design principles.

    Science.gov (United States)

    Lampa, Samuel; Alvarsson, Jonathan; Spjuth, Ola

    2016-01-01

    Predictive modelling in drug discovery is challenging to automate as it often contains multiple analysis steps and might involve cross-validation and parameter tuning that create complex dependencies between tasks. With large-scale data or when using computationally demanding modelling methods, e-infrastructures such as high-performance or cloud computing are required, adding to the existing challenges of fault-tolerant automation. Workflow management systems can aid in many of these challenges, but the currently available systems are lacking in the functionality needed to enable agile and flexible predictive modelling. We here present an approach inspired by elements of the flow-based programming paradigm, implemented as an extension of the Luigi system which we name SciLuigi. We also discuss the experiences from using the approach when modelling a large set of biochemical interactions using a shared computer cluster.Graphical abstract.

  2. Molecular modelling of S-RNases involved in almond self-incompatibility

    Directory of Open Access Journals (Sweden)

    Angel eFernandez i Marti

    2012-06-01

    Full Text Available Gametophytic self-incompatibility (GSI is a mechanism in flowering plants, to prevent inbreeding and promote outcrossing. GSI is under the control of a specific locus, known as the S-locus, which contains at least two genes, the RNase and the SFB. Active S-RNases in the style are essential for rejection of haploid pollen, when the pollen S-allele matches one of two S-alleles of the diploid pistil. However, the nature of their mutual interactions at genetic and biochemical levels remain unclear. Thus, detailed understanding of the protein structure involved in GSI may help in discovering how the proteins involved in GSI may function and how they fulfil their biological roles. To this end, 3D models of the SC (Sf and two SI (S8 and S23 S-RNases of almond were constructed, using comparative modelling tools. The modelled structures consisted of mixed α and β folds, with six helices and six beta-strands. However, the self-compatible (Sf RNase contained an additional extended loop between the conserved domains RC4 and C5, which may be involved in the manifestation of self-compatibility in almond.

  3. NST: Thermal Modeling for a Large Aperture Solar Telescope

    Science.gov (United States)

    Coulter, Roy

    2011-05-01

    Late in the 1990s the Dutch Open Telescope demonstrated that internal seeing in open, large aperture solar telescopes can be controlled by flushing air across the primary mirror and other telescope structures exposed to sunlight. In that system natural wind provides a uniform air temperature throughout the imaging volume, while efficiently sweeping heated air away from the optics and mechanical structure. Big Bear Solar Observatory's New Solar Telescope (NST) was designed to realize that same performance in an enclosed system by using both natural wind through the dome and forced air circulation around the primary mirror to provide the uniform air temperatures required within the telescope volume. The NST is housed in a conventional, ventilated dome with a circular opening, in place of the standard dome slit, that allows sunlight to fall only on an aperture stop and the primary mirror. The primary mirror is housed deep inside a cylindrical cell with only minimal openings in the side at the level of the mirror. To date, the forced air and cooling systems designed for the NST primary mirror have not been implemented, yet the telescope regularly produces solar images indicative of the absence of mirror seeing. Computational Fluid Dynamics (CFD) analysis of the NST primary mirror system along with measurements of air flows within the dome, around the telescope structure, and internal to the mirror cell are used to explain the origin of this seemingly incongruent result. The CFD analysis is also extended to hypothetical systems of various scales. We will discuss the results of these investigations.

  4. Barnes maze testing strategies with small and large rodent models.

    Science.gov (United States)

    Rosenfeld, Cheryl S; Ferguson, Sherry A

    2014-02-26

    Spatial learning and memory of laboratory rodents is often assessed via navigational ability in mazes, most popular of which are the water and dry-land (Barnes) mazes. Improved performance over sessions or trials is thought to reflect learning and memory of the escape cage/platform location. Considered less stressful than water mazes, the Barnes maze is a relatively simple design of a circular platform top with several holes equally spaced around the perimeter edge. All but one of the holes are false-bottomed or blind-ending, while one leads to an escape cage. Mildly aversive stimuli (e.g. bright overhead lights) provide motivation to locate the escape cage. Latency to locate the escape cage can be measured during the session; however, additional endpoints typically require video recording. From those video recordings, use of automated tracking software can generate a variety of endpoints that are similar to those produced in water mazes (e.g. distance traveled, velocity/speed, time spent in the correct quadrant, time spent moving/resting, and confirmation of latency). Type of search strategy (i.e. random, serial, or direct) can be categorized as well. Barnes maze construction and testing methodologies can differ for small rodents, such as mice, and large rodents, such as rats. For example, while extra-maze cues are effective for rats, smaller wild rodents may require intra-maze cues with a visual barrier around the maze. Appropriate stimuli must be identified which motivate the rodent to locate the escape cage. Both Barnes and water mazes can be time consuming as 4-7 test trials are typically required to detect improved learning and memory performance (e.g. shorter latencies or path lengths to locate the escape platform or cage) and/or differences between experimental groups. Even so, the Barnes maze is a widely employed behavioral assessment measuring spatial navigational abilities and their potential disruption by genetic, neurobehavioral manipulations, or drug

  5. Models for physics of the very small and very large

    CERN Document Server

    Buckholtz, Thomas J

    2016-01-01

    This monograph tackles three challenges. First, show math that matches known elementary particles. Second, apply the math to match other known physics data. Third, predict future physics data The math features solutions to isotropic pairs of isotropic quantum harmonic oscillators. This monograph matches some solutions to known elementary particles. Matched properties include spin and types of interactions in which the particles partake Other solutions point to possible elementary particles This monograph applies the math and the extended particle list. Results narrow gaps between physics data and theory. Results pertain to elementary particles, astrophysics, and cosmology For example, this monograph predicts properties for beyond-the-Standard-Model elementary particles, proposes descriptions of dark matter and dark energy, provides new relationships between known physics constants, includes theory that dovetails with the ratio of dark matter to ordinary matter, includes math that dovetails with the number of ...

  6. Variable Tension, Large Deflection Ideal String Model For Transverse Motions

    CERN Document Server

    Ciblak, Namik

    2013-01-01

    In this study a new approach to the problem of transverse vibrations of an ideal string is presented. Unlike previous studies, assumptions such as constant tension, inextensibility, constant crosssectional area, small deformations and slopes are all removed. The main result is that, despite such relaxations in the model, not only does the final equation remain linear, but, it is exactly the same equation obtained in classical treatments. First, an "infinitesimals" based analysis, similar to historical methods, is given. However, an alternative and much stronger approach, solely based on finite quantities, is also presented. Furthermore, it is shown that the same result can also be obtained by Lagrangian mechanics, which indicates the compatibility of the original method with those based on energy and variational principles. Another interesting result is the relation between the force distribution and string displacement in static cases, which states that the force distribution per length is proportional to th...

  7. Differences in the morphine-induced inhibition of small and large intestinal transit: Involvement of central and peripheral μ-opioid receptors in mice.

    Science.gov (United States)

    Matsumoto, Kenjiro; Umemoto, Hiroyuki; Mori, Tomohisa; Akatsu, Ryuya; Saito, Shinichiro; Tashima, Kimihito; Shibasaki, Masahiro; Kato, Shinichi; Suzuki, Tsutomu; Horie, Syunji

    2016-01-15

    Constipation is the most common side effect of morphine. Morphine acts centrally and on peripheral sites within the enteric nervous system. There are a few comprehensive studies on morphine-induced constipation in the small and large intestine by the activation of central and peripheral μ-opioid receptors. We investigated the differences in the inhibition of the small and large intestinal transit in normal and morphine-tolerant mice. Morphine reduced the geometric center in the fluorescein isothiocyanate-dextran assay and prolonged the bead expulsion time in a dose-dependent manner. The inhibitory effects of morphine were blocked by μ-opioid antagonist β-funaltrexamine, but not by δ- and κ-opioid antagonists. The peripheral opioid receptor antagonist, naloxone methiodide, partially blocked morphine's effect in the small intestine and completely blocked its effect in the large intestine. The intracerebroventricular administration of naloxone significantly reversed the delay of small intestinal transit but did not affect morphine-induced inhibition of large intestinal transit. Naloxone methiodide completely reversed the inhibition of large intestinal transit in normal and morphine-tolerant mice. Naloxone methiodide partially reversed the morphine-induced inhibition of small intestinal transit in normal mice but completely reversed the effects of morphine in tolerant mice. Chronic treatment with morphine results in tolerance to its inhibitory effect on field-stimulated contraction in the isolated small intestine but not in the large intestine. These results suggest that peripheral and central opioid receptors are involved in morphine-induced constipation in the small and large intestine during the early stage of treatment, but the peripheral receptors mainly regulate constipation during long-term morphine treatment.

  8. Wall-modeled large-eddy simulation of transonic airfoil buffet at high Reynolds number

    Science.gov (United States)

    Fukushima, Yuma; Kawai, Soshi

    2016-11-01

    In this study, we conduct the wall-modeled large-eddy simulation (LES) of transonic buffet phenomena over the OAT15A supercritical airfoil at high Reynolds number. The transonic airfoil buffet involves shock-turbulent boundary layer interactions and shock vibration associated with the flow separation downstream of the shock wave. The wall-modeled LES developed by Kawai and Larsson PoF (2012) is tuned on the K supercomputer for high-fidelity simulation. We first show the capability of the present wall-modeled LES on the transonic airfoil buffet phenomena and then investigate the detailed flow physics of unsteadiness of shock waves and separated boundary layer interaction phenomena. We also focus on the sustaining mechanism of the buffet phenomena, including the source of the pressure waves propagated from the trailing edge and the interactions between the shock wave and the generated sound waves. This work was supported in part by MEXT as a social and scientific priority issue to be tackled by using post-K computer. Computer resources of the K computer was provided by the RIKEN Advanced Institute for Computational Science (Project ID: hp150254).

  9. Parathyroid gland involvement by thyroid cancer: results from a large series of thyroidectomies performed in two italian university hospitals and review of the literature.

    Science.gov (United States)

    Papi, Giampaolo; Corrado, Stefania; Fadda, Guido; Maiorana, Antonino; Maccio, Livia; Corsello, Salvatore Maria; Pontecorvi, Alfredo

    2014-01-01

    Objectives.Parathyroid involvement by thyroid cancer (TC) has not been frequently investigated in thyroidectomy-based studies. We aimed to detect cases of parathyroid invasion by TC in a large series of thyroidectomies and to review the literature on this topic. Study Design. A 10-yr period database research was made from the files of the Section of Pathology of two Italian University Hospitals. Out of 22,310 thyroidectomies, 10 patients with parathyroid involvement by TC were found. Results. The 10 patients, 7 females and 3 males, aged 55 ± 14 years (range 34-76, median 56) had papillary thyroid carcinoma and accounted for 0.4% of subjects affected by all TCs and submitted to thyroidectomy. The tumor invaded perithyroid soft tissues in 6 patients and central neck (level VI) lymph nodes in 3. Parathyroid involvement by TC occurred by infiltration in 6 cases, extension through an intervening pseudocapsule in 1, and both patterns in 3. All patients are alive and disease free at 5.6 ± 3-yr follow-up. Conclusion. Limited to thyroidectomy series, our results and literature data suggest that parathyroid involvement by TC has a 0.4-3.9% incidence rate; mainly affects women in their sixth-seventh decade of life; is associated to a good prognosis, unless massive extrathyroid extension of TC occurs.

  10. Parathyroid Gland Involvement by Thyroid Cancer: Results from a Large Series of Thyroidectomies Performed in Two Italian University Hospitals and Review of the Literature

    Directory of Open Access Journals (Sweden)

    Giampaolo Papi

    2014-01-01

    Full Text Available Objectives.Parathyroid involvement by thyroid cancer (TC has not been frequently investigated in thyroidectomy-based studies. We aimed to detect cases of parathyroid invasion by TC in a large series of thyroidectomies and to review the literature on this topic. Study Design. A 10-yr period database research was made from the files of the Section of Pathology of two Italian University Hospitals. Out of 22,310 thyroidectomies, 10 patients with parathyroid involvement by TC were found. Results. The 10 patients, 7 females and 3 males, aged 55±14 years (range 34–76, median 56 had papillary thyroid carcinoma and accounted for 0.4% of subjects affected by all TCs and submitted to thyroidectomy. The tumor invaded perithyroid soft tissues in 6 patients and central neck (level VI lymph nodes in 3. Parathyroid involvement by TC occurred by infiltration in 6 cases, extension through an intervening pseudocapsule in 1, and both patterns in 3. All patients are alive and disease free at 5.6±3-yr follow-up. Conclusion. Limited to thyroidectomy series, our results and literature data suggest that parathyroid involvement by TC has a 0.4–3.9% incidence rate; mainly affects women in their sixth-seventh decade of life; is associated to a good prognosis, unless massive extrathyroid extension of TC occurs.

  11. Large scale flow visualization and anemometry applied to lab on chip models of porous media

    CERN Document Server

    Paiola, Johan; Bodiguel, Hugues

    2016-01-01

    The following is a report on an experimental technique allowing to quantify and map the velocity field with a very high resolution and a simple equipment in large 2D devices. A simple Shlieren technique is proposed to reinforce the contrast in the images and allow you to detect seeded particles that are pixel-sized or even inferior to it. The velocimetry technique that we have reported on is based on auto-correlation functions of the pixel intensity, which we have shown are directly related to the magnitude of the local average velocity. The characteristic time involved in the decorrelation of the signal is proportional to the tracer size and inversely proportional to the average velocity. We have reported on a detailed discussion about the optimization of relevant involved parameters, the spatial resolution and the accuracy of the method. The technique is then applied to a model porous media made of a random channel network. We show that it is highly efficient to determine the magnitude of the flow in each o...

  12. Bulk Motions in Large-Scale Void Models

    CERN Document Server

    Tomita, K

    1999-01-01

    To explain the puzzling situation in the observed bulk flows on scales $\\sim 150 h^{-1}$ Mpc ($H_0 = 100 h^{-1}$ km sec$^{-1}$ Mpc$^{-1}$), we consider the observational behavior of spherically symmetric inhomogeneous cosmological models, which consist of inner and outer homogeneous regions connected by a shell or an intermediate self-similar region. It is assumed that the present matter density parameter in the inner region is smaller than that in the outer region, and the present Hubble parameter in the inner region is larger than that in the outer region. Then galaxies in the inner void-like region can be seen to have a bulk motion relative to matter in the outer region, when we observe them at a point O deviated from the center C of the inner region. Their velocity $v_p$ in the CD direction is equal to the difference of two Hubble parameters multiplied by the distance between C and O. It is found also that the velocity $v_d$ corresponding to CMB dipole anisotropy observed at O is by a factor $\\approx 10$ ...

  13. Steady state modeling of large diameter crystal growth using baffles

    Science.gov (United States)

    Sahai, Vivek; Williamson, John; Overfelt, Tony

    1991-01-01

    Buoyancy driven flow in the crystal melt is one of the leading causes of segregation. Natural convection arises from the presence of thermal and/or solutal gradients in the melt and it is not possible to completely eliminate the convection even in the low gravity environment of space. This paper reports the results of computational modeling research that is being done in preparation for space-based experiments. The commercial finite element code FIDAP was used to simulate the steady convection of a gallium-doped germanium alloy in a Bridgman-Stockbarger furnace. In particular, the study examines the convection-suppressing benefits of inserting cylindrical baffles in the molten region to act as viscous dampers. These thin baffles are assumed to be inert and noncontaminating. The results from this study show the manner in which the streamlines, velocities, and temperature fields at various gravity levels are affected by the presence of baffles. The effects of changing both the number and position of the baffles are examined and the advantages and disadvantages of using baffles are considered.

  14. Large-eddy simulations of a propelled submarine model

    Science.gov (United States)

    Posa, Antonio; Balaras, Elias

    2015-11-01

    The influence of the propeller on the wake as well as the evolution of the turbulent boundary layers over an appended notional submarine geometry (DARPA SUBOFF) is reported. The present approach utilizes a wall-resolved LES, coupled with an immersed boundary formulation, to simulate the flow model scale Reynolds numbers (Re = 1 . 2 e + 06 , based on the free-stream velocity and the length of the body). Cylindrical coordinates are adopted, and the computational grid is composed of 3.5 billion nodes. Our approach has been validated on the appended submarine body in towed conditions (without propeller), by comparisons to wind tunnel experiments in the literature. The comparison with the towed configuration shows profound modifications in the boundary layer over the stern surface, due to flow acceleration, with higher values of turbulent kinetic energy in the inner layer and lower values in the outer layer. This behavior was found tied to a different topology of the coherent structures between propelled and towed cases. The wake is also highly affected, and the momentum deficit displays a non-monotonic evolution downstream. An axial peak of turbulent kinetic energy replaces the bimodal distribution of the stresses in the wake, observed in the towed configuration. Supported by ONR Grant N000141110455, monitored by Dr. Ki-Han Kim.

  15. A model for simulating the influence of a spatial distribution of large circular macropores on surface runoff

    Science.gov (United States)

    Léonard, J.; Perrier, E.; de Marsily, G.

    2001-12-01

    This paper reports the development and test, at the scale of 1 m2, of an event- based model that aims at simulating the influence of a spatial distribution of large circular macropores on surface runoff. The main originality of this model is that it focuses on the way macropores are supplied with water at the soil surface, by coupling an original model for water interception by individual macropores to a high-resolution spatialized overland flow model. A three-step evaluation of the model was carried out, involving (1) an experimental test of the model for water interception by macropores; (2) a sensitivity analysis of the model to time and space discretization; and (3) a comparison between numerical and field results in the case of runoff on a crusted soil surface with a population of large macropores made by termites in the Sahel. The model was found to accurately simulate the effect of a spatial distribution of large macropores on runoff, and it showed that small heterogeneities, like macropores or areas where a crust has been destroyed, which cover a very limited proportion of the soil surface, can have a high impact on runoff.

  16. Large Scale Modelling of Glow Discharges or Non - Plasmas

    Science.gov (United States)

    Shankar, Sadasivan

    The Electron Velocity Distribution Function (EVDF) in the cathode fall of a DC helium glow discharge was evaluated from a numerical solution of the Boltzmann Transport Equation(BTE). The numerical technique was based on a Petrov-Galerkin technique and a unique combination of streamline upwinding with self -consistent feedback-based shock-capturing. EVDF for the cathode fall was solved at 1 Torr, as a function of position x, axial velocity v_{rm x}, radial velocity v_{rm r}, and time t. The electron-neutral collisions consisted of elastic, excitation, and ionization processes. The algorithm was optimized and vectorized to speed execution by more than a factor of 10 on CRAY-XMP. Efficient storage schemes were used to save the memory allocation required by the algorithm. The analysis of the solution of BTE was done in terms of the 8-moments that were evaluated. Higher moments were found necessary to study the momentum and energy fluxes. The time and length scales were estimated and used as a basis for the characterization of DC glow discharges. Based on an exhaustive study of Knudsen numbers, it was observed that the electrons in the cathode fall were in the transition or Boltzmann regime. The shortest relaxation time was the momentum relaxation and the longest times were the ionization and energy relaxation times. The other times in the processes were that for plasma reaction, diffusion, convection, transit, entropy relaxation, and that for mean free flight between the collisions. Different models were classified based on the moments, time scales, and length scales in their applicability to glow discharges. These consisted of BTE with different number af phase and configuration dimensions, Bhatnagar-Gross-Krook equation, moment equations (e.g. Drift-Diffusion, Drift-Diffusion-Inertia), and spherical harmonic expansions.

  17. Soil hydrologic characterization for modeling large scale soil remediation protocols

    Science.gov (United States)

    Romano, Nunzio; Palladino, Mario; Di Fiore, Paola; Sica, Benedetto; Speranza, Giuseppe

    2014-05-01

    In Campania Region (Italy), the Ministry of Environment identified a National Interest Priority Sites (NIPS) with a surface of about 200,000 ha, characterized by different levels and sources of pollution. This area, called Litorale Domitio-Agro Aversano includes some polluted agricultural land, belonging to more than 61 municipalities in the Naples and Caserta provinces. In this area, a high level spotted soil contamination is moreover due to the legal and outlaw industrial and municipal wastes dumping, with hazardous consequences also on the quality of the water table. The EU-Life+ project ECOREMED (Implementation of eco-compatible protocols for agricultural soil remediation in Litorale Domizio-Agro Aversano NIPS) has the major aim of defining an operating protocol for agriculture-based bioremediation of contaminated agricultural soils, also including the use of crops extracting pollutants to be used as biomasses for renewable energy production. In the framework of this project, soil hydrologic characterization plays a key role and modeling water flow and solute transport has two main challenging points on which we focus on. A first question is related to the fate of contaminants infiltrated from stormwater runoff and the potential for groundwater contamination. Another question is the quantification of fluxes and spatial extent of root water uptake by the plant species employed to extract pollutants in the uppermost soil horizons. Given the high variability of spatial distribution of pollutants, we use soil characterization at different scales, from field scale when facing root water uptake process, to regional scale when simulating interaction between soil hydrology and groundwater fluxes.

  18. Imaging characteristics of diffuse large cell extra nodal non-Hodgkin's lymphoma involving the palate and maxillary sinus: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Nadendla, Lakshmi Kavitha; Meduri, Venkateswarlu; Paramkusam, Geetha [Kamineni Institute of Dental Sciences, Nalgonda (India)

    2012-06-15

    Non-Hodgkin's lymphomas are a group of highly diverse malignancies and have a strong tendency to affect organs and tissues that do not ordinarily contain lymphoid cells. Primary extra nodal lymphoma of the hard palate is rare. Here, we present a case of diffuse large B cell lymphoma in a 60-year-old male patient that manifested as slightly painful ulcerated growth on the edentulous right maxillary alveolar ridge extending onto the palate, closely resembling carcinoma of the alveolar ridge. Computed tomography images showed the involvement of the maxillary sinus and right nasal cavity, along with destruction of hard palate, superiorly extending into the orbit. This case report highlights the importance of imaging to evaluate the exact extent of such large malignant lesions, which is essential for treatment planning.

  19. Stochastic modelling of a large subduction interface earthquake in Wellington, New Zealand

    Science.gov (United States)

    Francois-Holden, C.; Zhao, J.

    2012-12-01

    The Wellington region, home of New Zealand's capital city, is cut by a number of major right-lateral strike slip faults, and is underlain by the currently locked west-dipping subduction interface between the down going Pacific Plate, and the over-riding Australian Plate. A potential cause of significant earthquake loss in the Wellington region is a large magnitude (perhaps 8+) "subduction earthquake" on the Australia-Pacific plate interface, which lies ~23 km beneath Wellington City. "It's Our Fault" is a project involving a comprehensive study of Wellington's earthquake risk. Its objective is to position Wellington city to become more resilient, through an encompassing study of the likelihood of large earthquakes, and the effects and impacts of these earthquakes on humans and the built environment. As part of the "It's Our Fault" project, we are working on estimating ground motions from potential large plate boundary earthquakes. We present the latest results on ground motion simulations in terms of response spectra and acceleration time histories. First we characterise the potential interface rupture area based on previous geodetically-derived estimates interface of slip deficit. Then, we entertain a suitable range of source parameters, including various rupture areas, moment magnitudes, stress drops, slip distributions and rupture propagation directions. Our comprehensive study also includes simulations from historical large world subduction events translated into the New Zealand subduction context, such as the 2003 M8.3 Tokachi-Oki Japan earthquake and the M8.8 2010 Chili earthquake. To model synthetic seismograms and the corresponding response spectra we employed the EXSIM code developed by Atkinson et al. (2009), with a regional attenuation model based on the 3D attenuation model for the lower North-Island which has been developed by Eberhart-Phillips et al. (2005). The resulting rupture scenarios all produce long duration shaking, and peak ground

  20. System Model Bias Processing Approach for Regional Coordinated States Information Involved Filtering

    Directory of Open Access Journals (Sweden)

    Zebo Zhou

    2016-01-01

    Full Text Available In the Kalman filtering applications, the conventional dynamic model which connects the states information of two consecutive epochs by state transition matrix is usually predefined and assumed to be invariant. Aiming to improve the adaptability and accuracy of dynamic model, we propose multiple historical states involved filtering algorithm. An autoregressive model is used as the dynamic model which is subsequently combined with observation model for deriving the optimal window-recursive filter formulae in the sense of minimum mean square error principle. The corresponding test statistics characteristics of system residuals are discussed in details. The test statistics of regional predicted residuals are then constructed in a time-window for model bias testing with two hypotheses, that is, the null and alternative hypotheses. Based on the innovations test statistics, we develop a model bias processing procedure including bias detection, location identification, and state correction. Finally, the minimum detectable bias and bias-to-noise ratio are both computed for evaluating the internal and external reliability of overall system, respectively.

  1. Pore scale modeling of reactive transport involved in geologic CO2 sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Qinjin [Los Alamos National Laboratory; Lichtner, Peter C [Los Alamos National Laboratory; Viswanathan, Hari S [Los Alamos National Laboratory; Abdel-fattah, Amr I [Los Alamos National Laboratory

    2009-01-01

    We apply a multi-component reactive transport lattice Boltzmann model developed in previolls studies to modeling the injection of a C02 saturated brine into various porous media structures at temperature T=25 and 80 C. The porous media are originally consisted of calcite. A chemical system consisting of Na+, Ca2+, Mg2+, H+, CO2(aq), and CI-is considered. The fluid flow, advection and diHusion of aqueous species, homogeneous reactions occurring in the bulk fluid, as weB as the dissolution of calcite and precipitation of dolomite are simulated at the pore scale. The effects of porous media structure on reactive transport are investigated. The results are compared with continuum scale modeling and the agreement and discrepancy are discussed. This work may shed some light on the fundamental physics occurring at the pore scale for reactive transport involved in geologic C02 sequestration.

  2. Model correction factor method for reliability problems involving integrals of non-Gaussian random fields

    DEFF Research Database (Denmark)

    Franchin, P.; Ditlevsen, Ove Dalager; Kiureghian, Armen Der

    2002-01-01

    The model correction factor method (MCFM) is used in conjunction with the first-order reliability method (FORM) to solve structural reliability problems involving integrals of non-Gaussian random fields. The approach replaces the limit-state function with an idealized one, in which the integrals...... are considered to be Gaussian. Conventional FORM analysis yields the linearization point of the idealized limit-state surface. A model correction factor is then introduced to push the idealized limit-state surface onto the actual limit-state surface. A few iterations yield a good approximation of the reliability...... reliability method; Model correction factor method; Nataf field integration; Non-Gaussion random field; Random field integration; Structural reliability; Pile foundation reliability...

  3. Modelling binaural processes involved in simultaneous reflection masking: limitations of current models

    DEFF Research Database (Denmark)

    Buchholz, Jörg

    2007-01-01

    Masked thresholds were measured for a single test reflection, masked by the direct sound, as a function of the reflection delay. This was done for diotic as well as for dichotic stimulus presentations and all stimuli were presented via headphones. The input signal was a 200-ms long broadband noise....... The dichotic threshold decreased with increasing reflection delay indicating an increase in binaural detection performance with increasing reflection delay. Comparing the dichotic threshold to the corresponding diotic threshold, for delays below 7-10 ms, the dichotic threshold was found to be higher than...... the diotic threshold while it was lower than the diotic threshold for larger delays. Hence, the binaural system seems to deteriorate auditory detection performance for very early reflections and to enhance auditory detection performance for later reflections. Existing binaural (detection) models...

  4. Modelling of phase equilibria and related properties of mixtures involving lipids

    DEFF Research Database (Denmark)

    Cunico, Larissa

    Many challenges involving physical and thermodynamic properties in the production of edible oils and biodiesel are observed, such as availability of experimental data and realiable prediction. In the case of lipids, a lack of experimental data for pure components and also for their mixtures in open...... literature was observed, what makes it necessary to development reliable predictive models from limited data. One of the first steps of this project was the creation of a database containing properties of mixtures involved in tasks related to process design, simulation, and optimization as well as design...... of chemicals based products. This database was combined with the existing lipids database of pure component properties. To contribute to the missing data, measurements of isobaric vapour-liquid equilibrium (VLE) data of two binary mixtures at two different pressures were performed using Differential Scanning...

  5. A comparative modeling and molecular docking study on Mycobacterium tuberculosis targets involved in peptidoglycan biosynthesis.

    Science.gov (United States)

    Fakhar, Zeynab; Naiker, Suhashni; Alves, Claudio N; Govender, Thavendran; Maguire, Glenn E M; Lameira, Jeronimo; Lamichhane, Gyanu; Kruger, Hendrik G; Honarparvar, Bahareh

    2016-11-01

    An alarming rise of multidrug-resistant Mycobacterium tuberculosis strains and the continuous high global morbidity of tuberculosis have reinvigorated the need to identify novel targets to combat the disease. The enzymes that catalyze the biosynthesis of peptidoglycan in M. tuberculosis are essential and noteworthy therapeutic targets. In this study, the biochemical function and homology modeling of MurI, MurG, MraY, DapE, DapA, Alr, and Ddl enzymes of the CDC1551 M. tuberculosis strain involved in the biosynthesis of peptidoglycan cell wall are reported. Generation of the 3D structures was achieved with Modeller 9.13. To assess the structural quality of the obtained homology modeled targets, the models were validated using PROCHECK, PDBsum, QMEAN, and ERRAT scores. Molecular dynamics simulations were performed to calculate root mean square deviation (RMSD) and radius of gyration (Rg) of MurI and MurG target proteins and their corresponding templates. For further model validation, RMSD and Rg for selected targets/templates were investigated to compare the close proximity of their dynamic behavior in terms of protein stability and average distances. To identify the potential binding mode required for molecular docking, binding site information of all modeled targets was obtained using two prediction algorithms. A docking study was performed for MurI to determine the potential mode of interaction between the inhibitor and the active site residues. This study presents the first accounts of the 3D structural information for the selected M. tuberculosis targets involved in peptidoglycan biosynthesis.

  6. The Cauchy problem for a model of immiscible gas flow with large data

    Energy Technology Data Exchange (ETDEWEB)

    Sande, Hilde

    2008-12-15

    The thesis consists of an introduction and two papers; 1. The solution of the Cauchy problem with large data for a model of a mixture of gases. 2. Front tracking for a model of immiscible gas flow with large data. (AG) refs, figs

  7. Conclusions of the NATO ARW on Large Scale Computations in Air Pollution Modelling

    DEFF Research Database (Denmark)

    1999-01-01

    Proceedings of the NATO Advanced Research Workshop on Large Scale Computations in Air Pollution Modelling, Sofia, Bulgaria, 6-10 July 1998......Proceedings of the NATO Advanced Research Workshop on Large Scale Computations in Air Pollution Modelling, Sofia, Bulgaria, 6-10 July 1998...

  8. Investigation of pulmonary involvement in inflammatory bowel disease in an experimental model of colitis.

    Science.gov (United States)

    Aydin, Bunyamin; Songur, Yıldıran; Songur, Necla; Aksu, Oğuzhan; Senol, Altug; Ciris, I Metin; Sutcu, Recep

    2016-09-01

    Inflammatory bowel disease (IBD) may also involve various extra-intestinal organs. Clinical studies have found asymptomatic/symptomatic pulmonary involvement in 1% to 6% of patients with IBD. The present study histopathologically investigated pulmonary involvement in an experimental model of colitis in order to demonstrate pulmonary tissue involvement in IBD and to expose potential etiological factors. It also explored the relation between inflammation and tissue concentrations of vascular endothelial growth factor (VEGF) and tumor necrosis factor α (TNF-α). The study comprised 24 male Wistar albino rats. The rats were divided into four groups of six rats each. Acute colitis was induced in two separate groups using either the dextran sulphate sodium (DSS) or trinitrobenzene sulfonic acid (TNBS) method, while the other two groups were used as controls for each model of colitis. Wallace scoring was used for macroscopic assessment of colitis, and the lungs were histopathologically examined. Concentrations of VEGF and TNF-α in pulmonary tissue were measured by the enzyme-linked immunosorbent assay method. The number of animals that had alveolar hemorrhage was significantly higher in the TNBS-induced colitis and DSS-induced colitis groups compared to their own control groups (p = 0.015 and p = 0.015, respectively). VEGF and TNF-α concentrations in pulmonary tissues were significantly increased in both the TNBS colitis and DSS colitis groups compared to their own control groups (p = 0.002 and p = 0.004, respectively; and p = 0.002 and p = 0.002, respectively). The present study demonstrated that significant and serious histopathological changes directly associated with colitis occur in the lungs in IBD.

  9. Investigation of pulmonary involvement in inflammatory bowel disease in an experimental model of colitis

    Science.gov (United States)

    Aydin, Bunyamin; Songur, Yıldıran; Songur, Necla; Aksu, Oğuzhan; Senol, Altug; Ciris, I. Metin; Sutcu, Recep

    2016-01-01

    Background/Aims: Inflammatory bowel disease (IBD) may also involve various extra-intestinal organs. Clinical studies have found asymptomatic/symptomatic pulmonary involvement in 1% to 6% of patients with IBD. The present study histopathologically investigated pulmonary involvement in an experimental model of colitis in order to demonstrate pulmonary tissue involvement in IBD and to expose potential etiological factors. It also explored the relation between inflammation and tissue concentrations of vascular endothelial growth factor (VEGF) and tumor necrosis factor α (TNF-α). Methods: The study comprised 24 male Wistar albino rats. The rats were divided into four groups of six rats each. Acute colitis was induced in two separate groups using either the dextran sulphate sodium (DSS) or trinitrobenzene sulfonic acid (TNBS) method, while the other two groups were used as controls for each model of colitis. Wallace scoring was used for macroscopic assessment of colitis, and the lungs were histopathologically examined. Concentrations of VEGF and TNF-α in pulmonary tissue were measured by the enzyme-linked immunosorbent assay method. Results: The number of animals that had alveolar hemorrhage was significantly higher in the TNBS-induced colitis and DSS-induced colitis groups compared to their own control groups (p = 0.015 and p = 0.015, respectively). VEGF and TNF-α concentrations in pulmonary tissues were significantly increased in both the TNBS colitis and DSS colitis groups compared to their own control groups (p = 0.002 and p = 0.004, respectively; and p = 0.002 and p = 0.002, respectively). Conclusions: The present study demonstrated that significant and serious histopathological changes directly associated with colitis occur in the lungs in IBD. PMID:27539446

  10. A case of tonsillar anaplastic large cell lymphoma-anaplastic lymphoma kinase negative: An unusual site of involvement with review of literature

    Directory of Open Access Journals (Sweden)

    Umesh Das

    2014-01-01

    Full Text Available We present this unusual case of the clinical importance of a 50-year-old male patient who presented with foreign body sensation in the throat and halitosis of 20 days duration. On examination, there were no palpable lymph nodes and oral cavity revealed an ulcero proliferative growth over the right tonsil. Computed tomography of the paranasal sinuses and neck revealed a heterogeneously enhancing mass involving the right tonsil measuring 3.8 cm × 3 cm. Biopsy of the tonsillar mass was suggestive of anaplastic large cell lymphoma (ALCL with neoplastic large cells positive for CD30, epithelial membrane antigen and CD3 and negative for Tdt, CD56, anaplastic lymphoma kinase (ALK and cytokeratin. A diagnosis of ALK negative ALCL Stage IA was made and the patient was started on chemotherapy with cyclophosphamide, doxorubicin, vincristine, and prednisone every 3 weeks. He received six cycles of chemotherapy followed by 33 gray involved region radiotherapy and reassessment showed total regression of the tonsillar lesion. The patient is in complete remission and now under follow-up for the last 2 years

  11. [Intravascular large B-cell lymphoma with pontine involvement successfully treated with R-hyper-CVAD/R-MTX-Ara-C regimen].

    Science.gov (United States)

    Nakazato, Tomonori; Suzuki, Kazuhito; Mihara, Ai; Sanada, Yukinari; Yoshida, Sachiko; Kakimoto, Tsunayuki

    2010-02-01

    A 47-year-old woman was admitted to our hospital complaining of persistent fever and dry cough in June 2007. CT scan showed hepatosplenomegaly. Laboratory data revealed pancytopenia and increased levels of LDH and soluble interleukin-2 receptor. Malignant lymphoma was suspected, but histological diagnosis was difficult because superficial lymph nodes could not be palpated. Histological examination of the bone marrow biopsy specimen demonstrated the proliferation of large atypical lymphoid cells positive for CD20 and CD79a in the small capillaries, leading to the diagnosis of intravascular large B-cell lymphoma (IVLBCL). Although the results of neurological examination and CSF analysis were normal, head MRI showed a T2-hyperintense lesion in the pons. We chose R-hyper-CVAD/R-MTX-Ara-C alternating therapy with MTX intrathecal injection because CNS involvement in IVLBCL was highly suspected, and she responded well. Head MRI showed the disappearance of the abnormal signal in the pons after one cycle of R-hyper-CVAD. Five cycles of R-hyper-CVAD/R-MTX-Ara-C were performed and complete remission was obtained. R-hyper-CVAD/R-MTX-Ara-C alternating therapy was effective in an IVLBCL patient with CNS involvement.

  12. Peripheral nervous system involvement in systemic lupus erythematosus: Prevalence, clinical and immunological characteristics, treatment and outcome of a large cohort from a single centre.

    Science.gov (United States)

    Toledano, Pilar; Orueta, Ramón; Rodríguez-Pintó, Ignasi; Valls-Solé, Josep; Cervera, Ricard; Espinosa, Gerard

    2017-07-01

    Disorders of peripheral nervous system in patients with systemic lupus erythematosus (PNS-SLE) are a major cause of morbidity. The aims of the present study were to determine the prevalence of PNS-SLE involvement in a large cohort of SLE patients from a single centre, to characterize such involvement, treatment modalities and outcome, and to identify the possible variables that may be associated with its presence. We performed an observational cross-sectional study that included all SLE patients being followed in our department between March and December 2015 who met at least one of the PNS-SLE case definitions proposed in 1999 by the American College of Rheumatology. Overall, 93 out of 524 (17,7%) patients presented with PNS-SLE syndrome; 90 (96.8%) of them were women with a mean age at PNS-SLE syndrome diagnosis was 44.8±14.1years and the average time from diagnosis of SLE to PNS-SLE diagnosis was 88 (range, 541-400) months. The most frequent manifestation was polyneuropathy (36.6%), followed by non-compression mononeuropathy (23.7%), cranial neuropathy and myasthenia gravis (7.5%, each), and Guillain-Barré syndrome (1.1%). The most frequent electrodiagnostic tests (EDX) pattern was axonal degeneration, present in 49 patients that corresponded to 80.3% of the overall EDX patterns. Mixed sensory-motor neuropathy was the most common type of involvement accounted for 56% of cases. Thirty-six out of 90 (40%) received glucocorticoids and/or immunosuppressant agents. Overall, global response (complete and/or partial) to treatments was achieved in 77.4% of patients without differences between the types of PNS-SLE involvement. Older age at SLE diagnosis (37.3±14.8 versus 30.8±12; p=0.001) and absence of hematologic involvement as cumulative SLE manifestation (11.8% versus 21.5%; p=0.034) had independent statistical significant associations with PNS-SLE development. The PNS-SLE involvement is not uncommon. Its most frequent manifestation is sensory-motor axonal

  13. PET/CT Scanner and Bone Marrow Biopsy in Detection of Bone Marrow Involvement in Diffuse Large B-Cell Lymphoma

    Science.gov (United States)

    El Karak, Fadi; Bou-Orm, Ibrahim R.; Ghosn, Marwan; Kattan, Joseph; Farhat, Fadi; Ibrahim, Toni; Jreige, Mario; El Cheikh, Jean

    2017-01-01

    Evaluation of bone marrow involvement (BMI) is paramount in diffuse large B-cell lymphoma (DLBCL) for prognostic and therapeutic reasons. PET/CT scanner (PET) is now a routine examination for the staging of DLBCL with prognostic and therapeutic implications. This study evaluates the role of PET for detecting marrow involvement compared to bone marrow biopsy (BMB). This monocentric study included 54 patients diagnosed with DLBCL between 2009 and 2013 and who had FDG PET/CT in a pre-treatment setting. A correlation analysis of the detection of BMI by PET and BMB was performed. A prognostic evaluation of BMI by BMB and/or PET/CT and correlation with an overall 2-year survival were analyzed. PET was more sensitive for the detection of BMI than BMB (92.3% vs. 38.5%). It can be considered a discriminatory Pre-BMB test with a negative predictive value of 97.6%. In addition, BMI by PET had a prognostic value with strong correlation with progression-free survival (PFS) (HR = 3.81; p = 0.013) and overall survival (OS) (HR = 4.12; p = 0.03) while the BMB had not. PET shows superior performance to the BMB for the detection of marrow involvement in DLBCL. It may be considered as the first line examination of bone marrow instead of the biopsy. PMID:28099514

  14. The sheep as a large osteoporotic model for orthopaedic research in humans

    DEFF Research Database (Denmark)

    Cheng, L.; Ding, Ming; Li, Z.;

    2008-01-01

    Although small animals as rodents are very popular animals for osteoporosis models , large animals models are necessary for research of human osteoporotic diseases. Sheep osteoporosis models are becoming more important because of its unique advantages for osteoporosis reseach. Sheep are docile...... intake restriction and glucocorticoid application are the most effective methods for sheep osteoporosis model. Sheep osteoporosis model is an ideal animal model for studying various medicines reacting to osteoporosis and other treatment methods such as prosthetic replacement reacting to osteoporotic...

  15. A large scale hydrological model combining Budyko hypothesis and stochastic soil moisture model

    Science.gov (United States)

    Cong, Z.; Zhang, X.

    2012-04-01

    Based on the Budyko hypothesis, the actual evapotranspiration, E,is controlled by the water conditions and the energy conditions, which are represented by the amount of annual precipitation, P and potential evaporation, E0, respectively. Some theoretical or empirical equations have been proposed to represent the Budyko curve. We here select Choudhury's equation to describe the Budyko curve (Mezentsev, 1954; Choudhury, 1999; Yang et al., 2008; Roderick and Farquhar, 2011). ɛ = (1+ φ -α)-1/α ,ɛ = E-,φ = E0 P P Rodriguez-Iturbe et al. (1999) proposed a stochastic soil moisture model based on a Poisson distributed rainfall assumption. Porporato et al. (2004) described the average water balance based on stochastic soil moisture model as following, γ- 1 ɛ = 1 -φ(·γ)φ--(·e-γ),γ = Zr- Γ γ- - Γ γ-,γ h φ φ where, h means the average rainfall depth, Zr means basin water storage ability. Combining these two equation, we can get the relation between α and γ. Then we develop a large scale hydrological model to estimate annual runoff from P, E0, h and Zr. ( -α)- 1/α 0.5946 Zr- R = (1- ɛ)P,ɛ = 1+ φ ,a = 0.7078γ ,γ = h This method has good performance when it is applied to estimate annual runoff in the Yellow River Basin and the Yangtze River Basin. The impacts of climate changes (P, E0 and h) and human activities (Zr) are also discussed with this method.

  16. University Physics Students' Use of Models in Explanations of Phenomena Involving Interaction between Metals and Electromagnetic Radiation.

    Science.gov (United States)

    Redfors, Andreas; Ryder, Jim

    2001-01-01

    Examines third year university physics students' use of models when explaining familiar phenomena involving interaction between metals and electromagnetic radiation. Concludes that few students use a single model consistently. (Contains 27 references.) (DDR)

  17. Wide band modeling of large power transformer windings for very fast transient overvoltage (VFTO) analysis

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    There are some difficulties in using multi-transmission-line (MTL) model for wide band modeling of whole windings of the large power transformer. In this paper, the normalized MTL model is firstly de- rived, with which not only the difficulty of modeling windings with different turn-lengths using MTL can be solved, but also the model can be extended to the modeling of the multi-winding transformer. Secondly, both MTL model and the lumped circuit model on turn basis are mathematically compared in validation of the frequency range and it is pointed out that the lumped circuit model on turn basis is generally valid below 2.5 MHz for EHV and UHV power transformers. Finally, based on the MTL equations, a novel lumped circuit model is derived and it is shown that the valid frequency range of the new circuit is extended to about 4 MHz for modeling large EHV and UHV power transformer windings.

  18. Social Work Involvement in Advance Care Planning: Findings from a Large Survey of Social Workers in Hospice and Palliative Care Settings.

    Science.gov (United States)

    Stein, Gary L; Cagle, John G; Christ, Grace H

    2017-03-01

    Few data are available describing the involvement and activities of social workers in advance care planning (ACP). We sought to provide data about (1) social worker involvement and leadership in ACP conversations with patients and families; and (2) the extent of functions and activities when these discussions occur. We conducted a large web-based survey of social workers employed in hospice, palliative care, and related settings to explore their role, participation, and self-rated competency in facilitating ACP discussions. Respondents were recruited through the Social Work Hospice and Palliative Care Network and the National Hospice and Palliative Care Organization. Descriptive analyses were conducted on the full sample of respondents (N = 641) and a subsample of clinical social workers (N = 456). Responses were analyzed to explore differences in ACP involvement by practice setting. Most clinical social workers (96%) reported that social workers in their department are conducting ACP discussions with patients/families. Majorities also participate in, and lead, ACP discussions (69% and 60%, respectively). Most respondents report that social workers are responsible for educating patients/families about ACP options (80%) and are the team members responsible for documenting ACP (68%). Compared with other settings, oncology and inpatient palliative care social workers were less likely to be responsible for ensuring that patients/families are informed of ACP options and documenting ACP preferences. Social workers are prominently involved in facilitating, leading, and documenting ACP discussions. Policy-makers, administrators, and providers should incorporate the vital contributions of social work professionals in policies and programs supporting ACP.

  19. Modelling and pathway identification involving the transport mechanism of a complex metabolic system in batch culture

    Science.gov (United States)

    Yuan, Jinlong; Zhang, Xu; Zhu, Xi; Feng, Enmin; Yin, Hongchao; Xiu, Zhilong

    2014-06-01

    The bio-dissimilation of glycerol to 1,3-propanediol (1,3-PD) by Klebsiella pneumoniae (K. pneumoniae) can be characterized by a complex metabolic system of interactions among biochemical fluxes, metabolic compounds, key enzymes and genetic regulation. In this paper, in consideration of the fact that the transport ways of 1,3-PD and glycerol with different weights across cell membrane are still unclear in batch culture, we consider 121 possible metabolic pathways and establish a novel mathematical model which is represented by a complex metabolic system. Taking into account the difficulty in accurately measuring the concentration of intracellular substances and the absence of equilibrium point for the metabolic system of batch culture, the novel approach used here is to define quantitatively biological robustness of the intracellular substance concentrations for the overall process of batch culture. To determine the most possible metabolic pathway, we take the defined biological robustness as cost function and establish an identification model, in which 1452 system parameters and 484 pathway parameters are involved. Simultaneously, the identification model is subject to the metabolic system, continuous state constraints and parameter constraints. As such, solving the identification model by a serial program is a very complicated task. We propose a parallel migration particle swarm optimization algorithm (MPSO) capable of solving the identification model in conjunction with the constraint transcription and smoothing approximation techniques. Numerical results show that the most possible metabolic pathway and the corresponding metabolic system can reasonably describe the process of batch culture.

  20. A Computational Model of a Descending Mechanosensory Pathway Involved in Active Tactile Sensing.

    Directory of Open Access Journals (Sweden)

    Jan M Ache

    2015-07-01

    Full Text Available Many animals, including humans, rely on active tactile sensing to explore the environment and negotiate obstacles, especially in the dark. Here, we model a descending neural pathway that mediates short-latency proprioceptive information from a tactile sensor on the head to thoracic neural networks. We studied the nocturnal stick insect Carausius morosus, a model organism for the study of adaptive locomotion, including tactually mediated reaching movements. Like mammals, insects need to move their tactile sensors for probing the environment. Cues about sensor position and motion are therefore crucial for the spatial localization of tactile contacts and the coordination of fast, adaptive motor responses. Our model explains how proprioceptive information about motion and position of the antennae, the main tactile sensors in insects, can be encoded by a single type of mechanosensory afferents. Moreover, it explains how this information is integrated and mediated to thoracic neural networks by a diverse population of descending interneurons (DINs. First, we quantified responses of a DIN population to changes in antennal position, motion and direction of movement. Using principal component (PC analysis, we find that only two PCs account for a large fraction of the variance in the DIN response properties. We call the two-dimensional space spanned by these PCs 'coding-space' because it captures essential features of the entire DIN population. Second, we model the mechanoreceptive input elements of this descending pathway, a population of proprioceptive mechanosensory hairs monitoring deflection of the antennal joints. Finally, we propose a computational framework that can model the response properties of all important DIN types, using the hair field model as its only input. This DIN model is validated by comparison of tuning characteristics, and by mapping the modelled neurons into the two-dimensional coding-space of the real DIN population. This

  1. A Computational Model of a Descending Mechanosensory Pathway Involved in Active Tactile Sensing.

    Science.gov (United States)

    Ache, Jan M; Dürr, Volker

    2015-07-01

    Many animals, including humans, rely on active tactile sensing to explore the environment and negotiate obstacles, especially in the dark. Here, we model a descending neural pathway that mediates short-latency proprioceptive information from a tactile sensor on the head to thoracic neural networks. We studied the nocturnal stick insect Carausius morosus, a model organism for the study of adaptive locomotion, including tactually mediated reaching movements. Like mammals, insects need to move their tactile sensors for probing the environment. Cues about sensor position and motion are therefore crucial for the spatial localization of tactile contacts and the coordination of fast, adaptive motor responses. Our model explains how proprioceptive information about motion and position of the antennae, the main tactile sensors in insects, can be encoded by a single type of mechanosensory afferents. Moreover, it explains how this information is integrated and mediated to thoracic neural networks by a diverse population of descending interneurons (DINs). First, we quantified responses of a DIN population to changes in antennal position, motion and direction of movement. Using principal component (PC) analysis, we find that only two PCs account for a large fraction of the variance in the DIN response properties. We call the two-dimensional space spanned by these PCs 'coding-space' because it captures essential features of the entire DIN population. Second, we model the mechanoreceptive input elements of this descending pathway, a population of proprioceptive mechanosensory hairs monitoring deflection of the antennal joints. Finally, we propose a computational framework that can model the response properties of all important DIN types, using the hair field model as its only input. This DIN model is validated by comparison of tuning characteristics, and by mapping the modelled neurons into the two-dimensional coding-space of the real DIN population. This reveals the versatility

  2. Formulation of Subgrid Variability and Boundary-Layer Cloud Cover in Large-Scale Models

    Science.gov (United States)

    2007-11-02

    soils have been specifically evaluated in terms of a van Genuchten formulation. The CAPS model was originally formulated for inclusion in large...terrestrial atmospheric boundary lay- ers, suitable for inclusion in large-scale models. The ABL mixing scheme (Troen and Mahrt, 1986) includes both...AFGL soil sodel (OSU-PL land-surface scheme) coupled to a boundary layer model developed by Jan Paegle, Univ. Utah. Ciudad Universitaria Pabellon 2

  3. Experimental Investigation of Wave-Induced Ship Hydroelastic Vibrations by Large-Scale Model Measurement in Coastal Waves

    Directory of Open Access Journals (Sweden)

    Jialong Jiao

    2016-01-01

    Full Text Available Ship hydroelastic vibration is an issue involving mutual interactions among inertial, hydrodynamic, and elastic forces. The conventional laboratory tests for wave-induced hydroelastic vibrations of ships are performed in tank conditions. An alternative approach to the conventional laboratory basin measurement, proposed in this paper, is to perform tests by large-scale model measurement in real sea waves. In order to perform this kind of novel experimental measurement, a large-scale free running model and the experiment scheme are proposed and introduced. The proposed testing methodology is quite general and applicable to a wide range of ship hydrodynamic experimental research. The testing procedure is presented by illustrating a 5-hour voyage trial of the large-scale model carried out at Huludao harbor of China in August 2015. Hammer tests were performed to identify the natural frequencies of the ship model at the beginning of the tests. Then a series of tests under different sailing conditions were carried out to investigate the vibrational characteristics of the model. As a postvoyage analysis, load, pressure, acceleration, and motion responses of the model are studied with respect to different time durations based on the measured data.

  4. A BAROTROPIC QUASI-GEOSTROPHIC MODEL WITH LARGE-SCALE TOPOGRAPHY, FRICTION AND HEATING

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Based on the barotropic equations including large-scale topography, friction and heat factor, a barotropic quasi-geostrophic model with large-scale topography, friction and heating is obtained by means of scale analysis and small parameter method. It is shown that this equation is a basic one, which is used to study the influence of the Tibetan Plateau on the large-scale flow in the atmosphere. If the friction and heating effect of large-scale topography are neglected, this model will degenerate to the general barotropic quasi-geostrophic one.

  5. Modeling Research on Manufacturing Execution System Based on Large-scale System Cybernetics

    Institute of Scientific and Technical Information of China (English)

    WU Yu; XU Xiao-dong; LI Cong-xin

    2008-01-01

    A cybernetics model of manufacturing execution system (MES_CM) was proposed and studied from the viewpoint of cybernetics.Combining with the features of manufacturing system,the MES_CM was modeled by "generalized modeling" method that is discussed in large-scale system theory.The mathematical model of MES_CM was constructed by the generalized operator model,and the main characteristics of MES_CM were analyzed.

  6. A Verilog-A large signal model for InP DHBT including thermal effects

    Science.gov (United States)

    Yuxia, Shi; Zhi, Jin; Zhijian, Pan; Yongbo, Su; Yuxiong, Cao; Yan, Wang

    2013-06-01

    A large signal model for InP/InGaAs double heterojunction bipolar transistors including thermal effects has been reported, which demonstrated good agreements of simulations with measurements. On the basis of the previous model in which the double heterojunction effect, current blocking effect and high current effect in current expression are considered, the effect of bandgap narrowing with temperature has been considered in transport current while a formula for model parameters as a function of temperature has been developed. This model is implemented by Verilog-A and embedded in ADS. The proposed model is verified with DC and large signal measurements.

  7. Boolean Modeling of Cellular and Molecular Pathways Involved in Influenza Infection

    Science.gov (United States)

    Anderson, Christopher S.; DeDiego, Marta L.; Topham, David J.; Thakar, Juilee

    2016-01-01

    Systems virology integrates host-directed approaches with molecular profiling to understand viral pathogenesis. Self-contained statistical approaches that combine expression profiles of genes with the available databases defining the genes involved in the pathways (gene-sets) have allowed characterization of predictive gene-signatures associated with outcome of the influenza virus (IV) infection. However, such enrichment techniques do not take into account interactions among pathways that are responsible for the IV infection pathogenesis. We investigate dendritic cell response to seasonal H1N1 influenza A/New Caledonia/20/1999 (NC) infection and infer the Boolean logic rules underlying the interaction network of ligand induced signaling pathways and transcription factors. The model reveals several novel regulatory modes and provides insights into mechanism of cross talk between NFκB and IRF mediated signaling. Additionally, the logic rule underlying the regulation of IL2 pathway that was predicted by the Boolean model was experimentally validated. Thus, the model developed in this paper integrates pathway analysis tools with the dynamic modeling approaches to reveal the regulation between signaling pathways and transcription factors using genome-wide transcriptional profiles measured upon influenza infection. PMID:26981147

  8. Boolean Modeling of Cellular and Molecular Pathways Involved in Influenza Infection

    Directory of Open Access Journals (Sweden)

    Christopher S. Anderson

    2016-01-01

    Full Text Available Systems virology integrates host-directed approaches with molecular profiling to understand viral pathogenesis. Self-contained statistical approaches that combine expression profiles of genes with the available databases defining the genes involved in the pathways (gene-sets have allowed characterization of predictive gene-signatures associated with outcome of the influenza virus (IV infection. However, such enrichment techniques do not take into account interactions among pathways that are responsible for the IV infection pathogenesis. We investigate dendritic cell response to seasonal H1N1 influenza A/New Caledonia/20/1999 (NC infection and infer the Boolean logic rules underlying the interaction network of ligand induced signaling pathways and transcription factors. The model reveals several novel regulatory modes and provides insights into mechanism of cross talk between NFκB and IRF mediated signaling. Additionally, the logic rule underlying the regulation of IL2 pathway that was predicted by the Boolean model was experimentally validated. Thus, the model developed in this paper integrates pathway analysis tools with the dynamic modeling approaches to reveal the regulation between signaling pathways and transcription factors using genome-wide transcriptional profiles measured upon influenza infection.

  9. Boolean Modeling of Cellular and Molecular Pathways Involved in Influenza Infection.

    Science.gov (United States)

    Anderson, Christopher S; DeDiego, Marta L; Topham, David J; Thakar, Juilee

    2016-01-01

    Systems virology integrates host-directed approaches with molecular profiling to understand viral pathogenesis. Self-contained statistical approaches that combine expression profiles of genes with the available databases defining the genes involved in the pathways (gene-sets) have allowed characterization of predictive gene-signatures associated with outcome of the influenza virus (IV) infection. However, such enrichment techniques do not take into account interactions among pathways that are responsible for the IV infection pathogenesis. We investigate dendritic cell response to seasonal H1N1 influenza A/New Caledonia/20/1999 (NC) infection and infer the Boolean logic rules underlying the interaction network of ligand induced signaling pathways and transcription factors. The model reveals several novel regulatory modes and provides insights into mechanism of cross talk between NFκB and IRF mediated signaling. Additionally, the logic rule underlying the regulation of IL2 pathway that was predicted by the Boolean model was experimentally validated. Thus, the model developed in this paper integrates pathway analysis tools with the dynamic modeling approaches to reveal the regulation between signaling pathways and transcription factors using genome-wide transcriptional profiles measured upon influenza infection.

  10. Modeling the Effect of Climate Change on Large Fire Size, Counts, and Intensities Using the Large Fire Simulator (FSim)

    Science.gov (United States)

    Riley, K. L.; Haas, J. R.; Finney, M.; Abatzoglou, J. T.

    2013-12-01

    Changes in climate can be expected to cause changes in wildfire activity due to a combination of shifts in weather (temperature, precipitation, relative humidity, wind speed and direction) and vegetation. Changes in vegetation could include type conversions, altered forest structure, and shifts in species composition, the effects of which could be mitigated or exacerbated by management activities. Further, changes in suppression response and effectiveness may alter potential wildfire activity, as well as the consequences of wildfire. Feedbacks among these factors are extremely complex and uncertain. The ability to anticipate changes driven by fire weather (largely outside of human control) can lead to development of fire and fuel management strategies aimed at mitigating current and future risk. Therefore, in this study we focus on isolating the effects of climate-induced changes in weather on wildfire activity. Specifically, we investigated the effect of changes in weather on fire activity in the Canadian Rockies ecoregion, which encompasses Glacier National Park and several large wilderness areas to the south. To model the ignition, growth, and containment of wildfires, we used the Large Fire Simulator (FSim), which we coupled with current and projected future climatic conditions. Weather streams were based on data from 14 downscaled Global Circulation Models (GCMs) from the Coupled Model Intercomparison Project Phase 5 (CMIP5) using the Representative Concentration Pathways (RCP) 45 and 85 for the years 2040-2060. While all GCMs indicate increases in temperature for this area, which would be expected to exacerbate fire activity, precipitation predictions for the summer wildfire season are more variable, ranging from a decrease of approximately 50 mm to an increase of approximately 50 mm. Windspeeds are generally predicted to decrease, which would reduce rates of spread and fire intensity. The net effect of these weather changes on the size, number, and intensity

  11. Studies on BVD involving establishment of sentinel calves and assessment of herd immunity in a large dairy farm in Saudi Arabia.

    Science.gov (United States)

    Abu Elzein, Eltayb; Alkhalyifa, Mofeed

    2012-03-01

    Little information is published, so far, regarding bovine viral diarrhea (BVD) in Saudi Arabia and the Gulf region. This study is the first of its kind in the country. Its aim was to explore the BVD situation in a large dairy farm, which has been experiencing reproduction problems suggestive of BVD virus infection, albeit the practice of routine vaccination. The study took two pathways; the first involved establishment of a cohort of sentinel calves so as: (a) to note the BVD virus activity in the farm by following the time lapse and pattern for waning of the maternally derived antibodies and detection of any subsequent seroconversion and (b) to look for any clinical signs suggestive of BVD virus infection in these calves. The second pathway was to assess the level of herd immunity in the different age groups of lactating cows and maiden heifers. The obtained results were discussed, and control strategies were outlined.

  12. The N-terminal β-sheet of peroxiredoxin 4 in the large yellow croaker Pseudosciaena crocea is involved in its biological functions.

    Directory of Open Access Journals (Sweden)

    Yinnan Mu

    Full Text Available Peroxiredoxins (Prxs are thiol-specific antioxidant proteins that exhibit peroxidase and peroxynitrite reductase activities involved in the reduction of reactive oxygen species. The peroxiredoxin Prx4 from the large yellow croaker Pseudosciaena crocea is a typical 2-Cys Prx with an N-terminal signal peptide. We solved the crystal structure of Prx4 at 1.90 Å and revealed an N-terminal antiparallel β-sheet that contributes to the dimer interface. Deletion of this β-sheet decreased the in vitro peroxidase activity to about 50% of the wild-type. In vivo assays further demonstrated that removal of this β-sheet led to some impairment in the ability of Prx4 to negatively regulate nuclear factor-κB (NF-κB activity and to perform its role in anti-bacterial immunity. These results provide new insights into the structure and function relationship of a peroxiredoxin from bony fish.

  13. A LARGE EDDY SIMULATION TURBULENCE MODEL FOR COASTAL SEAS AND SHALLOW WATER PROBLEMS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In large scale motions of circulations in coastal seas and shallow-water problems, different characteristics of flow in the horizontal plane and in the vertical direction are expected. In this paper, a new large eddy simulation model was proposed. There are some differences between the present method and the other LES models. The philosophy of the large eddy simulation and the directional eddy viscosity method were applied in the horizontal plane and in the vertical direction, respectively. Comparied with the other LES models in which there is no difference between horizontal viscosity and vertical viscosity, the proposed method is resonable.

  14. Large-signal PIN diode model for ultra-fast photodetectors

    DEFF Research Database (Denmark)

    Krozer, Viktor; Fritsche, C

    2005-01-01

    A large-signal model for PIN photodetector is presented, which can be applied to ultra-fast photodetection and THz signal generation. The model takes into account the tunnelling and avalanche breakdown, which is important for avalanche photodiodes. The model is applied to ultra-fast superlattice...

  15. Activation of Rac1 and the exchange factor Vav3 are involved in NPM-ALK signaling in anaplastic large cell lymphomas.

    Science.gov (United States)

    Colomba, A; Courilleau, D; Ramel, D; Billadeau, D D; Espinos, E; Delsol, G; Payrastre, B; Gaits-Iacovoni, F

    2008-04-24

    The majority of anaplastic large cell lymphomas (ALCLs) express the nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) fusion protein, which is oncogenic due to its constitutive tyrosine kinase activity. Transformation by NPM-ALK not only increases proliferation, but also modifies cell shape and motility in both lymphoid and fibroblastic cells. We report that the Rac1 GTPase, a known cytoskeletal regulator, is activated by NPM-ALK in ALCL cell lines (Karpas 299 and Cost) and transfected cells (lymphoid Ba/F3 cells, NIH-3T3 fibroblasts). We have identified Vav3 as one of the exchange factors involved in Rac1 activation. Stimulation of Vav3 and Rac1 by NPM-ALK is under the control of Src kinases. It involves formation of a signaling complex between NPM-ALK, pp60(c-src), Lyn and Vav3, in which Vav3 associates with tyrosine 343 of NPM-ALK via its SH2 domain. Moreover, Vav3 is phosphorylated in NPM-ALK positive biopsies from patients suffering from ALCL, demonstrating the pathological relevance of this observation. The use of Vav3-specific shRNA and a dominant negative Rac1 mutant demonstrates the central role of GTPases in NPM-ALK elicited motility and invasion.

  16. Successful Gene Therapy in the RPGRIP1-deficient Dog: a Large Model of Cone–Rod Dystrophy

    Science.gov (United States)

    Lhériteau, Elsa; Petit, Lolita; Weber, Michel; Le Meur, Guylène; Deschamps, Jack-Yves; Libeau, Lyse; Mendes-Madeira, Alexandra; Guihal, Caroline; François, Achille; Guyon, Richard; Provost, Nathalie; Lemoine, Françoise; Papal, Samantha; El-Amraoui, Aziz; Colle, Marie-Anne; Moullier, Philippe; Rolling, Fabienne

    2014-01-01

    For the development of new therapies, proof-of-concept studies in large animal models that share clinical features with their human counterparts represent a pivotal step. For inherited retinal dystrophies primarily involving photoreceptor cells, the efficacy of gene therapy has been demonstrated in canine models of stationary cone dystrophies and progressive rod–cone dystrophies but not in large models of progressive cone–rod dystrophies, another important cause of blindness. To address the last issue, we evaluated gene therapy in the retinitis pigmentosa GTPase regulator interacting protein 1 (RPGRIP1)-deficient dog, a model exhibiting a severe cone–rod dystrophy similar to that seen in humans. Subretinal injection of AAV5 (n = 5) or AAV8 (n = 2) encoding the canine Rpgrip1 improved photoreceptor survival in transduced areas of treated retinas. Cone function was significantly and stably rescued in all treated eyes (18–72% of those recorded in normal eyes) up to 24 months postinjection. Rod function was also preserved (22–29% of baseline function) in four of the five treated dogs up to 24 months postinjection. No detectable rod function remained in untreated contralateral eyes. More importantly, treatment preserved bright- and dim-light vision. Efficacy of gene therapy in this large animal model of cone–rod dystrophy provides great promise for human treatment. PMID:24091916

  17. Possible Role of GADD45γ Methylation in Diffuse Large B-Cell Lymphoma: Does It Affect the Progression and Tissue Involvement?

    Directory of Open Access Journals (Sweden)

    İkbal Cansu Barış

    2015-12-01

    Full Text Available INTRODUCTION: Diffuse large B-cell lymphoma (DLBCL is the most common type of non-Hodgkin lymphoma among adults and is characterized by heterogeneous clinical, immunophenotypic, and genetic features. Different mechanisms deregulating cell cycle and apoptosis play a role in the pathogenesis of DLBCL. Growth arrest DNA damage-inducible 45 (GADD45γ is an important gene family involved in these mechanisms. The aims of this study are to determine the frequency of GADD45γ methylation, to evaluate the correlation between GADD45γ methylation and protein expression, and to investigate the relation between methylation status and clinicopathologic parameters in DLBCL tissues and reactive lymphoid node tissues from patients with reactive lymphoid hyperplasia. METHODS: Thirty-six tissue samples of DLBCL and 40 nonmalignant reactive lymphoid node tissues were analyzed in this study. Methylation-sensitive high-resolution melting analysis was used for the determination of GADD45γ methylation status. The GADD45γ protein expression was determined by immunohistochemistry. RESULTS: GADD45γ methylation was frequent (50.0% in DLBCL. It was also significantly higher in advanced-stage tumors compared with early-stage (p=0.041. In contrast, unmethylated GADD45γ was associated with nodal involvement as the primary anatomical site (p=0.040. DISCUSSION AND CONCLUSION: The results of this study show that, in contrast to solid tumors, the frequency of GADD45γ methylation is higher and this epigenetic alteration of GADD45γ may be associated with progression in DLBCL. In addition, nodal involvement is more likely to be present in patients with unmethylated GADD45γ.

  18. Constraints on Lorentz Invariance Violating Quantum Gravity and Large Extra Dimensions Models using High Energy Gamma Ray Observations

    CERN Document Server

    Stecker, F W

    2003-01-01

    Observations of the multi-TeV spectra of the nearby BL objects Mkn 421 and Mkn 501 exhibit the high energy cutoffs predicted to be the result of intergalactic annihilation interactions, primarily with infrared photons having a flux level as determined by various astronomical observations. After correction for this absorption effect, the derived intrinsic spectra of these multi-TeV sources can be explained within the framework of simple synchrotron self-Compton emission models. Stecker and Glashow have shown that the existence of such annihilations via electron-positron pair production interactions up to an energy of 20 TeV puts strong constraints on Lorentz invariance violation. Such constraints have important implications for Lorentz invariance violating (LIV) quantum gravity models as well as LIV models involving large extra dimensions. We also discuss the implications of observations of high energy gamma-rays from the Crab Nebula on constraining quantum gravity models.

  19. How uncertainty in socio-economic variables affects large-scale transport model forecasts

    DEFF Research Database (Denmark)

    Manzo, Stefano; Nielsen, Otto Anker; Prato, Carlo Giacomo

    2015-01-01

    A strategic task assigned to large-scale transport models is to forecast the demand for transport over long periods of time to assess transport projects. However, by modelling complex systems transport models have an inherent uncertainty which increases over time. As a consequence, the longer...... time, especially with respect to large-scale transport models. The study described in this paper contributes to fill the gap by investigating the effects of uncertainty in socio-economic variables growth rate projections on large-scale transport model forecasts, using the Danish National Transport...... the period forecasted the less reliable is the forecasted model output. Describing uncertainty propagation patterns over time is therefore important in order to provide complete information to the decision makers. Among the existing literature only few studies analyze uncertainty propagation patterns over...

  20. Integrated supply chain inventory model with quality improvement involving controllable lead time and backorder price discount

    Directory of Open Access Journals (Sweden)

    Prashant Jindal

    2016-06-01

    Full Text Available For the past four decades the integrated vendor and buyer supply chain inventory model has been an interesting topic, but quality improvement of defective items in the integrated inventory model with backorder price discount involving controllable lead time has been rarely discussed. The aim of this paper is to minimize the total related cost in the continuous review model by considering the order quantity, reorder point, lead time, process quality, backorder price discount and number of shipment as decision variables. Moreover, we assume that an investment function is used to improve the process quality. The lead time demand follows a normal distribution. In addition, the buyer offers backorder price discount to motivate the customers for possible backorders. There are some defective items in the arrival lot, so its treatment is also taken in account in this paper. We develop an iterative procedure for finding the optimal values of decision variables and numerical example is presented to illustrate the solution procedure. Additionally, sensitivity analysis with respect to major parameters is also carried out.

  1. De novo characterization of the spleen transcriptome of the large yellow croaker (Pseudosciaena crocea) and analysis of the immune relevant genes and pathways involved in the antiviral response

    KAUST Repository

    Mu, Yinnan

    2014-05-12

    The large yellow croaker (Pseudosciaena crocea) is an economically important marine fish in China. To understand the molecular basis for antiviral defense in this species, we used Illumia paired-end sequencing to characterize the spleen transcriptome of polyriboinosinic:polyribocytidylic acid [poly(I:C)]-induced large yellow croakers. The library produced 56,355,728 reads and assembled into 108,237 contigs. As a result, 15,192 unigenes were found from this transcriptome. Gene ontology analysis showed that 4,759 genes were involved in three major functional categories: biological process, cellular component, and molecular function. We further ascertained that numerous consensus sequences were homologous to known immune-relevant genes. Kyoto Encyclopedia of Genes and Genomes orthology mapping annotated 5,389 unigenes and identified numerous immune-relevant pathways. These immune-relevant genes and pathways revealed major antiviral immunity effectors, including but not limited to: pattern recognition receptors, adaptors and signal transducers, the interferons and interferon-stimulated genes, inflammatory cytokines and receptors, complement components, and B-cell and T-cell antigen activation molecules. Moreover, the partial genes of Toll-like receptor signaling pathway, RIG-I-like receptors signaling pathway, Janus kinase-Signal Transducer and Activator of Transcription (JAK-STAT) signaling pathway, and T-cell receptor (TCR) signaling pathway were found to be changed after poly(I:C) induction by real-time polymerase chain reaction (PCR) analysis, suggesting that these signaling pathways may be regulated by poly(I:C), a viral mimic. Overall, the antivirus-related genes and signaling pathways that were identified in response to poly(I:C) challenge provide valuable leads for further investigation of the antiviral defense mechanism in the large yellow croaker. © 2014 Mu et al.

  2. Various approaches to the modelling of large scale 3-dimensional circulation in the Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Shaji, C.; Bahulayan, N.; Rao, A.D.; Dube, S.K.

    In this paper, the three different approaches to the modelling of large scale 3-dimensional flow in the ocean such as the diagnostic, semi-diagnostic (adaptation) and the prognostic are discussed in detail. Three-dimensional solutions are obtained...

  3. Large Deviations for Stochastic Models of Two-Dimensional Second Grade Fluids

    Energy Technology Data Exchange (ETDEWEB)

    Zhai, Jianliang, E-mail: zhaijl@ustc.edu.cn [University of Science and Technology of China, School of Mathematical Sciences (China); Zhang, Tusheng, E-mail: Tusheng.Zhang@manchester.ac.uk [University of Manchester, School of Mathematics (United Kingdom)

    2017-06-15

    In this paper, we establish a large deviation principle for stochastic models of incompressible second grade fluids. The weak convergence method introduced by Budhiraja and Dupuis (Probab Math Statist 20:39–61, 2000) plays an important role.

  4. Large N transition in the 2D SU(N)xSU(N) nonlinear sigma model

    CERN Document Server

    Narayanan, R; Vicari, E

    2008-01-01

    We consider the characteristic polynomial associated with the smoothed two point function in two dimensional large N principal chiral model. We numerically show that it undergoes a transition at a critical distance of the order of the correlation length. The transition is in the same universality class as two dimensional large N QCD.

  5. A Simplified Model to Calculate AC Losses in Large 2G HTS Coils

    DEFF Research Database (Denmark)

    Song, Xiaowei (Andy); Mijatovic, Nenad; Jensen, Bogi Bech;

    2015-01-01

    AC losses are of great significance to quantify the performance of high temperature superconducting (HTS) devices. This paper presents a simplified model to calculate AC losses in large 2G HTS coils, which serves as a baseline to study HTS large scale applications such as electric machines. The m...

  6. Integrating resource selection into spatial capture-recapture models for large carnivores

    Science.gov (United States)

    K. M. Proffitt; J. F. Goldberg; M. Hebblewhite; R. Russell; B. S. Jimenez; H. S. Robinson; Kristine Pilgrim; Michael Schwartz

    2015-01-01

    Wildlife managers need reliable methods to estimate large carnivore densities and population trends; yet large carnivores are elusive, difficult to detect, and occur at low densities making traditional approaches intractable. Recent advances in spatial capture-recapture (SCR) models have provided new approaches for monitoring trends in wildlife abundance and...

  7. A Model for Teaching Large Classes: Facilitating a "Small Class Feel"

    Science.gov (United States)

    Lynch, Rosealie P.; Pappas, Eric

    2017-01-01

    This paper presents a model for teaching large classes that facilitates a "small class feel" to counteract the distance, anonymity, and formality that often characterize large lecture-style courses in higher education. One author (E. P.) has been teaching a 300-student general education critical thinking course for ten years, and the…

  8. Cadmium Handling, Toxicity and Molecular Targets Involved during Pregnancy: Lessons from Experimental Models

    Science.gov (United States)

    Santoyo-Sánchez, Mitzi; Thévenod, Frank; Barbier, Olivier

    2017-01-01

    Even decades after the discovery of Cadmium (Cd) toxicity, research on this heavy metal is still a hot topic in scientific literature: as we wrote this review, more than 1440 scientific articles had been published and listed by the PubMed.gov website during 2017. Cadmium is one of the most common and harmful heavy metals present in our environment. Since pregnancy is a very particular physiological condition that could impact and modify essential pathways involved in the handling of Cd, the prenatal life is a critical stage for exposure to this non-essential element. To give the reader an overview of the possible mechanisms involved in the multiple organ toxic effects in fetuses after the exposure to Cd during pregnancy, we decided to compile some of the most relevant experimental studies performed in experimental models and to summarize the advances in this field such as the Cd distribution and the factors that could alter it (diet, binding-proteins and membrane transporters), the Cd-induced toxicity in dams (preeclampsia, fertility, kidney injury, alteration in essential element homeostasis and bone mineralization), in placenta and in fetus (teratogenicity, central nervous system, liver and kidney). PMID:28737682

  9. Social Recovery Model: An 8-Year Investigation of Adolescent 12-step Group Involvement following Inpatient Treatment

    Science.gov (United States)

    Kelly, John F.; Brown, Sandra A.; Abrantes, Ana; Kahler, Christopher; Myers, Mark

    2013-01-01

    Background Despite widespread use of 12-step treatment approaches and referrals to Alcoholics Anonymous (AA) and Narcotics Anonymous (NA) by youth providers, little is known about the significance of these organizations in youth addiction recovery. Furthermore, existing evidence is based mostly on short-term follow-up and is limited methodologically. Methods Adolescent inpatients (N = 160; M age = 16, 40% female) were followed at 6-months, and at 1, 2, 4, 6, and 8 years post-treatment. Time-lagged, generalized estimating equations (GEE) modeled treatment outcome in relation to AA/NA attendance controlling for static and time-varying covariates. Robust regression (LOWESS) explored dose-response thresholds of AA/NA attendance on outcome. Results AA/NA attendance was common and intensive early post-treatment, but declined sharply and steadily over the 8-year period. Patients with greater addiction severity and those who believed they could not use substances in moderation were more likely to attend. Despite declining attendance, the effects related to AA/NA remained significant and consistent. Greater early participation was associated with better long-term outcomes. Conclusions Even though many youth discontinue AA/NA over time, attendees appear to benefit, and more severely substance-involved youth attend most. Successful early post-treatment engagement of youth in abstinence-supportive social contexts, such as AA/NA, may have long-term implications for alcohol and drug involvement into young adulthood. PMID:18557829

  10. The emission of α,ω-diphenylpolyenes: A model involving several molecular structures

    Science.gov (United States)

    Catalán, Javier

    2007-05-01

    Available photophysical evidence for the emission of α,ω-diphenylpolyenes is shown to be consistent with a previously reported model [J. Catalán, J.L.G. de Paz, J. Chem. Phys. 124 (2006) 034306] involving two electronically excited molecular structures of 1B u and C s symmetry, respectively. The 1B u structure is produced by direct light absorption from the all- trans form of the α,ω-diphenylpolyene in the ground state and its emission exhibits mirror symmetry with respect to the absorption of the compound. On the other hand, the C s structure is generated from the 1B u structure of the α,ω-diphenylpolyene by rotation about a C-C single bond in the polyene chain, its emission being red-shifted with respect to the previous one and exhibiting markedly decreased vibrational structure. At room temperature, both emissions give the excitation spectrum, which are ascribed to the first absorption band for the compound. It is shown that some polyenes may exist in more than one structure of C s symmetry in the excited electronic state with lower energy than that of the 1B u state, from which the C s structures are produced. Hence, more than one electronic structure may be involved in the deactivation processes of the 1B u state, which is initially populated upon photo-excitation of the polyene molecule in the ground electronic state.

  11. A Connectionist Modeling Approach to Rapid Analysis of Emergent Social Cognition Properties in Large-Populations

    Energy Technology Data Exchange (ETDEWEB)

    Perumalla, Kalyan S [ORNL; Schryver, Jack C [ORNL

    2009-01-01

    Traditional modeling methodologies, such as those based on rule-based agent modeling, are exhibiting limitations in application to rich behavioral scenarios, especially when applied to large population aggregates. Here, we propose a new modeling methodology based on a well-known "connectionist approach," and articulate its pertinence in new applications of interest. This methodology is designed to address challenges such as speed of model development, model customization, model reuse across disparate geographic/cultural regions, and rapid and incremental updates to models over time.

  12. Differential expression of genes involved in the degeneration and regeneration pathways in mouse models for muscular dystrophies.

    Science.gov (United States)

    Onofre-Oliveira, P C G; Santos, A L F; Martins, P M; Ayub-Guerrieri, D; Vainzof, M

    2012-03-01

    The genetically determined muscular dystrophies are caused by mutations in genes coding for muscle proteins. Differences in the phenotypes are mainly the age of onset and velocity of progression. Muscle weakness is the consequence of myofiber degeneration due to an imbalance between successive cycles of degeneration/regeneration. While muscle fibers are lost, a replacement of the degraded muscle fibers by adipose and connective tissues occurs. Major investigation points are to elicit the involved pathophysiological mechanisms to elucidate how each mutation can lead to a specific degenerative process and how the regeneration is stimulated in each case. To answer these questions, we used four mouse models with different mutations causing muscular dystrophies, Dmd (mdx), SJL/J, Large (myd) and Lama2 (dy2J) /J, and compared the histological changes of regeneration and fibrosis to the expression of genes involved in those processes. For regeneration, the MyoD, Myf5 and myogenin genes related to the proliferation and differentiation of satellite cells were studied, while for degeneration, the TGF-β1 and Pro-collagen 1α2 genes, involved in the fibrotic cascade, were analyzed. The result suggests that TGF-β1 gene is activated in the dystrophic process in all the stages of degeneration, while the activation of the expression of the pro-collagen gene possibly occurs in mildest stages of this process. We also observed that each pathophysiological mechanism acted differently in the activation of regeneration, with distinctions in the induction of proliferation of satellite cells, but with no alterations in stimulation to differentiation. Dysfunction of satellite cells can, therefore, be an important additional mechanism of pathogenesis in the dystrophic muscle.

  13. An EMQ inventory model for defective products involving rework and sales team's initiatives-dependent demand

    Science.gov (United States)

    Priyan, S.; Uthayakumar, R.

    2015-07-01

    This paper investigates the issue of an economic manufacturing quantity model for defective products involving imperfect production processes and rework. We consider that the demand is sensitive to promotional efforts/sales teams' initiatives as well as the setup cost can be reduced through further investment. It also assumes that fixed quantity multiple installments of the finished batch are delivered to customers at a fixed interval of time. The long-run average cost function is derived and its convexity is proved via differential calculus. An effective iterative solution procedure is developed to achieve optimal replenishment lot-size, setup cost and the initiatives of sales teams so that the total cost of system is minimized. Numerical and sensitivity analyses are performed to evaluate the outcome of the proposed solution procedure presented in this research.

  14. System Dynamics Modelling of the Processes Involving the Maintenance of the Naive T Cell Repertoire

    CERN Document Server

    Figueredo, Grazziela P; Whitbrook, Amanda

    2010-01-01

    The study of immune system aging, i.e. immunosenescence, is a relatively new research topic. It deals with understanding the processes of immunodegradation that indicate signs of functionality loss possibly leading to death. Even though it is not possible to prevent immunosenescence, there is great benefit in comprehending its causes, which may help to reverse some of the damage done and thus improve life expectancy. One of the main factors influencing the process of immunosenescence is the number and phenotypical variety of naive T cells in an individual. This work presents a review of immunosenescence, proposes system dynamics modelling of the processes involving the maintenance of the naive T cell repertoire and presents some preliminary results.

  15. Zebrafish larva as a reliable model for in vivo assessment of membrane remodeling involvement in the hepatotoxicity of chemical agents.

    Science.gov (United States)

    Podechard, Normand; Chevanne, Martine; Fernier, Morgane; Tête, Arnaud; Collin, Aurore; Cassio, Doris; Kah, Olivier; Lagadic-Gossmann, Dominique; Sergent, Odile

    2016-11-28

    The easy-to-use in vivo model, zebrafish larva, is being increasingly used to screen chemical-induced hepatotoxicity, with a good predictivity for various mechanisms of liver injury. However, nothing is known about its applicability in exploring the mechanism called membrane remodeling, depicted as changes in membrane fluidity or lipid raft properties. The aim of this study was, therefore, to substantiate the zebrafish larva as a suitable in vivo model in this context. Ethanol was chosen as a prototype toxicant because it is largely described, both in hepatocyte cultures and in rodents, as capable of inducing a membrane remodeling leading to hepatocyte death and liver injury. The zebrafish larva model was demonstrated to be fully relevant as membrane remodeling was maintained even after a 1-week exposure without any adaptation as usually reported in rodents and hepatocyte cultures. It was also proven to exhibit a high sensitivity as it discriminated various levels of cytotoxicity depending on the extent of changes in membrane remodeling. In this context, its sensitivity appeared higher than that of WIF-B9 hepatic cells, which is suited for analyzing this kind of hepatotoxicity. Finally, the protection afforded by a membrane stabilizer, ursodeoxycholic acid (UDCA), or by a lipid raft disrupter, pravastatin, definitely validated zebrafish larva as a reliable model to quickly assess membrane remodeling involvement in chemical-induced hepatotoxicity. In conclusion, this model, compatible with a high throughput screening, might be adapted to seek hepatotoxicants via membrane remodeling, and also drugs targeting membrane features to propose new preventive or therapeutic strategies in chemical-induced liver diseases. Copyright © 2016 John Wiley & Sons, Ltd.

  16. Regional modeling of large wildfires under current and potential future climates in Colorado and Wyoming, USA

    Science.gov (United States)

    West, Amanda; Kumar, Sunil; Jarnevich, Catherine S.

    2016-01-01

    Regional analysis of large wildfire potential given climate change scenarios is crucial to understanding areas most at risk in the future, yet wildfire models are not often developed and tested at this spatial scale. We fit three historical climate suitability models for large wildfires (i.e. ≥ 400 ha) in Colorado andWyoming using topography and decadal climate averages corresponding to wildfire occurrence at the same temporal scale. The historical models classified points of known large wildfire occurrence with high accuracies. Using a novel approach in wildfire modeling, we applied the historical models to independent climate and wildfire datasets, and the resulting sensitivities were 0.75, 0.81, and 0.83 for Maxent, Generalized Linear, and Multivariate Adaptive Regression Splines, respectively. We projected the historic models into future climate space using data from 15 global circulation models and two representative concentration pathway scenarios. Maps from these geospatial analyses can be used to evaluate the changing spatial distribution of climate suitability of large wildfires in these states. April relative humidity was the most important covariate in all models, providing insight to the climate space of large wildfires in this region. These methods incorporate monthly and seasonal climate averages at a spatial resolution relevant to land management (i.e. 1 km2) and provide a tool that can be modified for other regions of North America, or adapted for other parts of the world.

  17. Processes and parameters involved in modeling radionuclide transport from bedded salt repositories. Final report. Technical memorandum

    Energy Technology Data Exchange (ETDEWEB)

    Evenson, D.E.; Prickett, T.A.; Showalter, P.A.

    1979-07-01

    The parameters necessary to model radionuclide transport in salt beds are identified and described. A proposed plan for disposal of the radioactive wastes generated by nuclear power plants is to store waste canisters in repository sites contained in stable salt formations approximately 600 meters below the ground surface. Among the principal radioactive wastes contained in these canisters will be radioactive isotopes of neptunium, americium, uranium, and plutonium along with many highly radioactive fission products. A concern with this form of waste disposal is the possibility of ground-water flow occurring in the salt beds and endangering water supplies and the public health. Specifically, the research investigated the processes involved in the movement of radioactive wastes from the repository site by groundwater flow. Since the radioactive waste canisters also generate heat, temperature is an important factor. Among the processes affecting movement of radioactive wastes from a repository site in a salt bed are thermal conduction, groundwater movement, ion exchange, radioactive decay, dissolution and precipitation of salt, dispersion and diffusion, adsorption, and thermomigration. In addition, structural changes in the salt beds as a result of temperature changes are important. Based upon the half-lives of the radioactive wastes, he period of concern is on the order of a million years. As a result, major geologic phenomena that could affect both the salt bed and groundwater flow in the salt beds was considered. These phenomena include items such as volcanism, faulting, erosion, glaciation, and the impact of meteorites. CDM reviewed all of the critical processes involved in regional groundwater movement of radioactive wastes and identified and described the parameters that must be included to mathematically model their behavior. In addition, CDM briefly reviewed available echniques to measure these parameters.

  18. Involvement of EphB1 receptors signalling in models of inflammatory and neuropathic pain.

    Directory of Open Access Journals (Sweden)

    Vincent Cibert-Goton

    Full Text Available EphB receptors tyrosine kinases and ephrinB ligands were first identified as guidance molecules involved in the establishment of topographical mapping and connectivity in the nervous system during development. Later in development and into adulthood their primary role would switch from guidance to activity-dependent modulation of synaptic efficacy. In sensory systems, they play a role in both the onset of inflammatory and neuropathic pain, and in the establishment of central sensitisation, an NMDA-mediated form of synaptic plasticity thought to underlie most forms of chronic pain. We studied wild type and EphB1 knockout mice in a range of inflammatory and neuropathic pain models to determine 1, whether EphB1 expression is necessary for the onset and/or maintenance of persistent pain, regardless of origin; 2, whether in these models cellular and molecular changes, e.g. phosphorylation of the NR2B subunit of the NMDA receptor, increased c-fos expression or microglial activation, associated with the onset of pain, are affected by the lack of functional EphB1 receptors. Differences in phenotype were examined behaviourally, anatomically, biochemically and electrophysiologically. Our results establish firstly, that functional EphB1 receptors are not essential for the development of normal nociception, thermal or mechanical sensitivity. Secondly, they demonstrate a widespread involvement of EphB1 receptors in chronic pain. NR2B phosphorylation, c-fos expression and microglial activation are all reduced in EphB1 knockout mice. This last finding is intriguing, since microglial activation is supposedly triggered directly by primary afferents, therefore it was not expected to be affected. Interestingly, in some models of long-term pain (days, mechanical and thermal hyperalgesia develop both in wild type and EphB1 knockout mice, but recovery is faster in the latter, indicating that in particular models these receptors are required for the maintenance

  19. Evaluation of drought propagation in an ensemble mean of large-scale hydrological models

    Directory of Open Access Journals (Sweden)

    A. F. Van Loon

    2012-11-01

    Full Text Available Hydrological drought is increasingly studied using large-scale models. It is, however, not sure whether large-scale models reproduce the development of hydrological drought correctly. The pressing question is how well do large-scale models simulate the propagation from meteorological to hydrological drought? To answer this question, we evaluated the simulation of drought propagation in an ensemble mean of ten large-scale models, both land-surface models and global hydrological models, that participated in the model intercomparison project of WATCH (WaterMIP. For a selection of case study areas, we studied drought characteristics (number of droughts, duration, severity, drought propagation features (pooling, attenuation, lag, lengthening, and hydrological drought typology (classical rainfall deficit drought, rain-to-snow-season drought, wet-to-dry-season drought, cold snow season drought, warm snow season drought, composite drought.

    Drought characteristics simulated by large-scale models clearly reflected drought propagation; i.e. drought events became fewer and longer when moving through the hydrological cycle. However, more differentiation was expected between fast and slowly responding systems, with slowly responding systems having fewer and longer droughts in runoff than fast responding systems. This was not found using large-scale models. Drought propagation features were poorly reproduced by the large-scale models, because runoff reacted immediately to precipitation, in all case study areas. This fast reaction to precipitation, even in cold climates in winter and in semi-arid climates in summer, also greatly influenced the hydrological drought typology as identified by the large-scale models. In general, the large-scale models had the correct representation of drought types, but the percentages of occurrence had some important mismatches, e.g. an overestimation of classical rainfall deficit droughts, and an

  20. Structural subgrid-scale modeling for large-eddy simulation:A review

    Institute of Scientific and Technical Information of China (English)

    Hao Lu; Christopher J Rutland

    2016-01-01

    Accurately modeling nonlinear interactions in turbulence is one of the key challenges for large-eddy simu-lation (LES) of turbulence. In this article, we review recent studies on structural subgrid scale modeling, focusing on evaluating how well these models predict the effects of small scales. The article discusses a priori and a posteriori test results. Other nonlinear models are briefly discussed, and future prospects are noted.

  1. Subgrid-scale heat flux modeling for large eddy simulation of turbulent mixed convection

    OpenAIRE

    Morar, Dejan

    2014-01-01

    In the present work, new subgrid-scale (SGS) heat flux model for large eddy simulation (LES) of turbulent mixed convection is developed. The new model explicitly includes the buoyancy production term. It is based on the algebraic equations and dynamic procedure is applied to calculate model coefficients. An experiment on turbulent mixed convection to water in a vertical duct is used for validation of the model.

  2. Large animal and primate models of spinal cord injury for the testing of novel therapies.

    Science.gov (United States)

    Kwon, Brian K; Streijger, Femke; Hill, Caitlin E; Anderson, Aileen J; Bacon, Mark; Beattie, Michael S; Blesch, Armin; Bradbury, Elizabeth J; Brown, Arthur; Bresnahan, Jacqueline C; Case, Casey C; Colburn, Raymond W; David, Samuel; Fawcett, James W; Ferguson, Adam R; Fischer, Itzhak; Floyd, Candace L; Gensel, John C; Houle, John D; Jakeman, Lyn B; Jeffery, Nick D; Jones, Linda Ann Truett; Kleitman, Naomi; Kocsis, Jeffery; Lu, Paul; Magnuson, David S K; Marsala, Martin; Moore, Simon W; Mothe, Andrea J; Oudega, Martin; Plant, Giles W; Rabchevsky, Alexander Sasha; Schwab, Jan M; Silver, Jerry; Steward, Oswald; Xu, Xiao-Ming; Guest, James D; Tetzlaff, Wolfram

    2015-07-01

    Large animal and primate models of spinal cord injury (SCI) are being increasingly utilized for the testing of novel therapies. While these represent intermediary animal species between rodents and humans and offer the opportunity to pose unique research questions prior to clinical trials, the role that such large animal and primate models should play in the translational pipeline is unclear. In this initiative we engaged members of the SCI research community in a questionnaire and round-table focus group discussion around the use of such models. Forty-one SCI researchers from academia, industry, and granting agencies were asked to complete a questionnaire about their opinion regarding the use of large animal and primate models in the context of testing novel therapeutics. The questions centered around how large animal and primate models of SCI would be best utilized in the spectrum of preclinical testing, and how much testing in rodent models was warranted before employing these models. Further questions were posed at a focus group meeting attended by the respondents. The group generally felt that large animal and primate models of SCI serve a potentially useful role in the translational pipeline for novel therapies, and that the rational use of these models would depend on the type of therapy and specific research question being addressed. While testing within these models should not be mandatory, the detection of beneficial effects using these models lends additional support for translating a therapy to humans. These models provides an opportunity to evaluate and refine surgical procedures prior to use in humans, and safety and bio-distribution in a spinal cord more similar in size and anatomy to that of humans. Our results reveal that while many feel that these models are valuable in the testing of novel therapies, important questions remain unanswered about how they should be used and how data derived from them should be interpreted. Copyright © 2015 Elsevier

  3. PLATO: data-oriented approach to collaborative large-scale brain system modeling.

    Science.gov (United States)

    Kannon, Takayuki; Inagaki, Keiichiro; Kamiji, Nilton L; Makimura, Kouji; Usui, Shiro

    2011-11-01

    The brain is a complex information processing system, which can be divided into sub-systems, such as the sensory organs, functional areas in the cortex, and motor control systems. In this sense, most of the mathematical models developed in the field of neuroscience have mainly targeted a specific sub-system. In order to understand the details of the brain as a whole, such sub-system models need to be integrated toward the development of a neurophysiologically plausible large-scale system model. In the present work, we propose a model integration library where models can be connected by means of a common data format. Here, the common data format should be portable so that models written in any programming language, computer architecture, and operating system can be connected. Moreover, the library should be simple so that models can be adapted to use the common data format without requiring any detailed knowledge on its use. Using this library, we have successfully connected existing models reproducing certain features of the visual system, toward the development of a large-scale visual system model. This library will enable users to reuse and integrate existing and newly developed models toward the development and simulation of a large-scale brain system model. The resulting model can also be executed on high performance computers using Message Passing Interface (MPI).

  4. Modeling and Control of a Large Nuclear Reactor A Three-Time-Scale Approach

    CERN Document Server

    Shimjith, S R; Bandyopadhyay, B

    2013-01-01

    Control analysis and design of large nuclear reactors requires a suitable mathematical model representing the steady state and dynamic behavior of the reactor with reasonable accuracy. This task is, however, quite challenging because of several complex dynamic phenomena existing in a reactor. Quite often, the models developed would be of prohibitively large order, non-linear and of complex structure not readily amenable for control studies. Moreover, the existence of simultaneously occurring dynamic variations at different speeds makes the mathematical model susceptible to numerical ill-conditioning, inhibiting direct application of standard control techniques. This monograph introduces a technique for mathematical modeling of large nuclear reactors in the framework of multi-point kinetics, to obtain a comparatively smaller order model in standard state space form thus overcoming these difficulties. It further brings in innovative methods for controller design for systems exhibiting multi-time-scale property,...

  5. The pig as a large preclinical model for therapeutic human anti-cancer vaccine development

    DEFF Research Database (Denmark)

    Overgaard, Nana Haahr; Frøsig, Thomas Mørch; Welner, Simon

    2016-01-01

    Development of therapeutic cancer vaccines has largely been based on rodent models and the majority failed to establish therapeutic responses in clinical trials. We therefore used pigs as a large animal model for human cancer vaccine development due to the large similarity between the porcine...... and human immunome. We administered peptides derived from porcine IDO, a cancer antigen important in human disease, formulated in Th1-inducing adjuvants to outbred pigs. By in silico prediction 136 candidate IDO-derived peptides were identified and peptide-SLA class I complex stability measurements revealed...

  6. Molecular modeling and simulation of FabG, an enzyme involved in the fatty acid pathway of Streptococcus pyogenes.

    Science.gov (United States)

    Shafreen, Rajamohmed Beema; Pandian, Shunmugiah Karutha

    2013-09-01

    Streptococcus pyogenes (SP) is the major cause of pharyngitis accompanied by strep throat infections in humans. 3-keto acyl reductase (FabG), an important enzyme involved in the elongation cycle of the fatty acid pathway of S. pyogenes, is essential for synthesis of the cell-membrane, virulence factors and quorum sensing-related mechanisms. Targeting SPFabG may provide an important aid for the development of drugs against S. pyogenes. However, the absence of a crystal structure for FabG of S. pyogenes limits the development of structure-based drug designs. Hence, in the present study, a homology model of FabG was generated using the X-ray crystallographic structure of Aquifex aeolicus (PDB ID: 2PNF). The modeled structure was refined using energy minimization. Furthermore, active sites were predicted, and a large dataset of compounds was screened against SPFabG. The ligands were docked using the LigandFit module that is available from Discovery Studio version 2.5. From this list, 13 best hit ligands were chosen based on the docking score and binding energy. All of the 13 ligands were screened for Absorption, Distribution, Metabolism, Excretion and Toxicity (ADMET) properties. From this, the two best descriptors, along with one descriptor that lay outside the ADMET plot, were selected for molecular dynamic (MD) simulation. In vitro testing of the ligands using biological assays further substantiated the efficacy of the ligands that were screened based on the in silico methods.

  7. Exponential Decay of Loop Lengths in the Loop O( n) Model with Large n

    Science.gov (United States)

    Duminil-Copin, Hugo; Peled, Ron; Samotij, Wojciech; Spinka, Yinon

    2017-02-01

    The loop O( n) model is a model for a random collection of non-intersecting loops on the hexagonal lattice, which is believed to be in the same universality class as the spin O( n) model. It has been conjectured that both the spin and the loop O( n) models exhibit exponential decay of correlations when n > 2. We verify this for the loop O( n) model with large parameter n, showing that long loops are exponentially unlikely to occur, uniformly in the edge weight x. Our proof provides further detail on the structure of typical configurations in this regime. Putting appropriate boundary conditions, when nx 6 is sufficiently small, the model is in a dilute, disordered phase in which each vertex is unlikely to be surrounded by any loops, whereas when nx 6 is sufficiently large, the model is in a dense, ordered phase which is a small perturbation of one of the three ground states.

  8. Optimization of large-scale heterogeneous system-of-systems models.

    Energy Technology Data Exchange (ETDEWEB)

    Parekh, Ojas; Watson, Jean-Paul; Phillips, Cynthia Ann; Siirola, John; Swiler, Laura Painton; Hough, Patricia Diane (Sandia National Laboratories, Livermore, CA); Lee, Herbert K. H. (University of California, Santa Cruz, Santa Cruz, CA); Hart, William Eugene; Gray, Genetha Anne (Sandia National Laboratories, Livermore, CA); Woodruff, David L. (University of California, Davis, Davis, CA)

    2012-01-01

    Decision makers increasingly rely on large-scale computational models to simulate and analyze complex man-made systems. For example, computational models of national infrastructures are being used to inform government policy, assess economic and national security risks, evaluate infrastructure interdependencies, and plan for the growth and evolution of infrastructure capabilities. A major challenge for decision makers is the analysis of national-scale models that are composed of interacting systems: effective integration of system models is difficult, there are many parameters to analyze in these systems, and fundamental modeling uncertainties complicate analysis. This project is developing optimization methods to effectively represent and analyze large-scale heterogeneous system of systems (HSoS) models, which have emerged as a promising approach for describing such complex man-made systems. These optimization methods enable decision makers to predict future system behavior, manage system risk, assess tradeoffs between system criteria, and identify critical modeling uncertainties.

  9. Pharmacophore model of drugs involved in P-glycoprotein multidrug resistance: explanation of structural variety (hypothesis).

    Science.gov (United States)

    Pajeva, Ilza K; Wiese, Michael

    2002-12-19

    A general pharmacophore model of P-glycoprotein (P-gp) drugs is proposed that is based on a highly diverse data set and relates to the verapamil binding site of the protein. It is derived from structurally different drugs using the program GASP. The pharmacophore model consists of two hydrophobic points, three hydrogen bond (HB) acceptor points, and one HB donor point. Pharmacophore patterns of various drugs are obtained, and different binding modes are presumed for some of them. It is concluded that the binding affinity of the drugs depends on the number of the pharmacophore points simultaneously involved in the interaction with P-gp. On the basis of the obtained results, a hypothesis is proposed to explain the broad structural variety of the P-gp substrates and inhibitors: (i) the verapamil binding site of P-gp has several points that can participate in hydrophobic and HB interactions; (ii) different drugs can interact with different receptor points in different binding modes.

  10. Semi-Implicit Algorithm for Elastoplastic Damage Models Involving Energy Integration

    Directory of Open Access Journals (Sweden)

    Ji Zhang

    2016-01-01

    Full Text Available This study aims to develop a semi-implicit constitutive integration algorithm for a class of elastoplastic damage models where calculation of damage energy release rates involves integration of free energy. The constitutive equations with energy integration are split into the elastic predictor, plastic corrector, and damage corrector. The plastic corrector is solved with an improved format of the semi-implicit spectral return mapping, which is characterized by constant flow direction and plastic moduli calculated at initial yield, enforcement of consistency at the end, and coordinate-independent formulation with an orthogonally similar stress tensor. The tangent stiffness consistent with the updating algorithm is derived. The algorithm is implemented with a recently proposed elastoplastic damage model for concrete, and several typical mechanical tests of reinforced concrete components are simulated. The present semi-implicit algorithm proves to achieve a balance between accuracy, stability, and efficiency compared with the implicit and explicit algorithms and calculate free energy accurately with small time steps.

  11. A structural model of customer satisfaction and trust in vendors involved in mobile commerce

    Directory of Open Access Journals (Sweden)

    Suki, N.M.

    2011-01-01

    Full Text Available The purpose of this paper is to provide an explanation of factors influencing customer satisfaction and trust in vendors involved in mobile commerce (m-commerce. The study sample consists of 200 respondents. Data were analyzed by employing structural equation modelling (SEM supported by AMOS 5.0 with maximum likelihood estimation in order to test the proposed hypotheses. The proposed model was empirically tested and results confirmed that users’ satisfaction with vendors in m-commerce was not significantly influenced by two antecedents of the vendor’s website quality: interactivity and customisation, and also two antecedents of mobile technology quality: usefulness and ease-of-use. Meanwhile, users’ trust towards the vendor in m-commerce is affected by users’ satisfaction with the vendor. Interestingly, vendor quality dimensions such as responsiveness and brand image influence customer satisfaction with vendors in m-commerce. Based on the findings, vendors in m-commerce should focus on the factors which generate more satisfaction and trust among customers. For vendors in general, the results can help them to better develop customer trust in m-commerce. Vendors of m-commerce can provide a more satisfying experience for customers.

  12. Involving mental health service users in suicide-related research: a qualitative inquiry model.

    Science.gov (United States)

    Lees, David; Procter, Nicholas; Fassett, Denise; Handley, Christine

    2016-03-01

    To describe the research model developed and successfully deployed as part of a multi-method qualitative study investigating suicidal service-users' experiences of mental health nursing care. Quality mental health care is essential to limiting the occurrence and burden of suicide, however there is a lack of relevant research informing practice in this context. Research utilising first-person accounts of suicidality is of particular importance to expanding the existing evidence base. However, conducting ethical research to support this imperative is challenging. The model discussed here illustrates specific and more generally applicable principles for qualitative research regarding sensitive topics and involving potentially vulnerable service-users. Researching into mental health service users with first-person experience of suicidality requires stakeholder and institutional support, researcher competency, and participant recruitment, consent, confidentiality, support and protection. Research with service users into their experiences of sensitive issues such as suicidality can result in rich and valuable data, and may also provide positive experiences of collaboration and inclusivity. If challenges are not met, objectification and marginalisation of service-users may be reinforced, and limitations in the evidence base and service provision may be perpetuated.

  13. Yeast Mitochondrial Interactosome Model: Metabolon Membrane Proteins Complex Involved in the Channeling of ADP/ATP

    Directory of Open Access Journals (Sweden)

    Benjamin Clémençon

    2012-02-01

    Full Text Available The existence of a mitochondrial interactosome (MI has been currently well established in mammalian cells but the exact composition of this super-complex is not precisely known, and its organization seems to be different from that in yeast. One major difference is the absence of mitochondrial creatine kinase (MtCK in yeast, unlike that described in the organization model of MI, especially in cardiac, skeletal muscle and brain cells. The aim of this review is to provide a detailed description of different partner proteins involved in the synergistic ADP/ATP transport across the mitochondrial membranes in the yeast Saccharomyces cerevisiae and to propose a new mitochondrial interactosome model. The ADP/ATP (Aacp and inorganic phosphate (PiC carriers as well as the VDAC (or mitochondrial porin catalyze the import and export of ADP, ATP and Pi across the mitochondrial membranes. Aacp and PiC, which appear to be associated with the ATP synthase, consist of two nanomotors (F0, F1 under specific conditions and form ATP synthasome. Identification and characterization of such a complex were described for the first time by Pedersen and co-workers in 2003.

  14. COMPUTATIONAL MODELING AND DRUG DESIGNING OF LIPOPROTEIN LIPASE (LPL INVOLVED IN ISCHEMIC STROKE

    Directory of Open Access Journals (Sweden)

    Maryam Torabizadeh

    2012-12-01

    Full Text Available Homology modeling and flexible docking of Lipoprotein Lipase has been studied in silico approach. Blast result was found to have similarity with Lipoprotein Lipase of 83% identity with 1LPA. Active site of LPL protein was identified by CASTP. Large potential drugs were designed for identifying molecules that can likely bind to protein target of interest. The different drug derivatives designed were used for docking with the generated structure, among the 10 derivatives designed, 3rd derivative showed highest docking result. The drug derivatives were docked to the protein by hydrogen bonding interactions and these interactions play an important role in the binding studies. Our investigations may be helpful for further studies.

  15. The Aliso Canyon Natural Gas Leak : Large Eddy Simulations for Modeling Atmospheric Dynamics and Interpretation of Observations.

    Science.gov (United States)

    Prasad, K.; Thorpe, A. K.; Duren, R. M.; Thompson, D. R.; Whetstone, J. R.

    2016-12-01

    The National Institute of Standards and Technology (NIST) has supported the development and demonstration of a measurement capability to accurately locate greenhouse gas sources and measure their flux to the atmosphere over urban domains. However, uncertainties in transport models which form the basis of all top-down approaches can significantly affect our capability to attribute sources and predict their flux to the atmosphere. Reducing uncertainties between bottom-up and top-down models will require high resolution transport models as well as validation and verification of dispersion models over an urban domain. Tracer experiments involving the release of Perfluorocarbon Tracers (PFTs) at known flow rates offer the best approach for validating dispersion / transport models. However, tracer experiments are limited by cost, ability to make continuous measurements, and environmental concerns. Natural tracer experiments, such as the leak from the Aliso Canyon underground storage facility offers a unique opportunity to improve and validate high resolution transport models, test leak hypothesis, and to estimate the amount of methane released.High spatial resolution (10 m) Large Eddy Simulations (LES) coupled with WRF atmospheric transport models were performed to simulate the dynamics of the Aliso Canyon methane plume and to quantify the source. High resolution forward simulation results were combined with aircraft and tower based in-situ measurements as well as data from NASA airborne imaging spectrometers. Comparison of simulation results with measurement data demonstrate the capability of the LES models to accurately model transport and dispersion of methane plumes over urban domains.

  16. Finite Mixture Multilevel Multidimensional Ordinal IRT Models for Large Scale Cross-Cultural Research

    NARCIS (Netherlands)

    M.G. de Jong (Martijn); J-B.E.M. Steenkamp (Jan-Benedict)

    2009-01-01

    textabstractWe present a class of finite mixture multilevel multidimensional ordinal IRT models for large scale cross-cultural research. Our model is proposed for confirmatory research settings. Our prior for item parameters is a mixture distribution to accommodate situations where different groups

  17. An efficient model for prediction of underwater noise due to pile driving at large ranges

    NARCIS (Netherlands)

    Nijhof, M.J.J.; Binnerts, B.; Jong, C.A.F. de; Ainslie, M.A.

    2014-01-01

    Modelling the sound levels in the water column due to pile driving operations nearby and out to large distances from the pile is crucial in assessing the likely impact on marine life. Standard numerical techniques for modelling the sound radiation from mechanical structures such as the finite elemen

  18. Successive inverse polynomial interpolation to optimize Smagorinsky's model for large-eddy simulation of homogeneous turbulence

    NARCIS (Netherlands)

    Geurts, Bernard J.; Meyers, Johan

    2006-01-01

    We propose the successive inverse polynomial interpolation method to optimize model parameters in subgrid parameterization for large-eddy simulation. This approach is illustrated for the Smagorinsky eddy-viscosity model used in homogeneous decaying turbulence. The optimal Smagorinsky parameter is re

  19. Role of subgrid-scale modeling in large eddy simulation of wind turbine wake interactions

    DEFF Research Database (Denmark)

    Sarlak, Hamid; Meneveau, C.; Sørensen, Jens Nørkær

    2015-01-01

    A series of simulations are carried out to evaluate specific features of the Large Eddy Simulation (LES) technique in wind turbine wake interactions. We aim to model wake interactions of two aligned model rotors. The effects of the rotor resolution, actuator line force filter size, and Reynolds...

  20. Induction of continuous expanding infrarenal aortic aneurysms in a large porcine animal model

    DEFF Research Database (Denmark)

    Kloster, Brian Ozeraitis; Lund, Lars; Lindholt, Jes S.

    2015-01-01

    BackgroundA large animal model with a continuous expanding infrarenal aortic aneurysm gives access to a more realistic AAA model with anatomy and physiology similar to humans, and thus allows for new experimental research in the natural history and treatment options of the disease. Methods10 pigs...

  1. Induction of continuous expanding infrarenal aortic aneurysms in a large porcine animal model

    DEFF Research Database (Denmark)

    Kloster, Brian Ozeraitis; Lund, Lars; Lindholt, Jes S.

    2015-01-01

    BACKGROUND: A large animal model with a continuous expanding infrarenal aortic aneurysm gives access to a more realistic AAA model with anatomy and physiology similar to humans, and thus allows for new experimental research in the natural history and treatment options of the disease. METHODS: 10...

  2. Successive inverse polynomial interpolation to optimize Smagorinsky's model for large-eddy simulation of homogeneous turbulence

    NARCIS (Netherlands)

    Geurts, Bernardus J.; Meyers, Johan

    We propose the successive inverse polynomial interpolation method to optimize model parameters in subgrid parameterization for large-eddy simulation. This approach is illustrated for the Smagorinsky eddy-viscosity model used in homogeneous decaying turbulence. The optimal Smagorinsky parameter is

  3. Modelling of a large scale reactor for plasma deposition of silicon

    NARCIS (Netherlands)

    Nienhuis, G. J.; W. Goedheer,

    1999-01-01

    A 2D fluid model for RF discharges in a mixture of silane and hydrogen is applied to a cylindrically symmetric reactor with an electrode radius large compared to the electrode separation. In the model the electron kinetics are included by solving the two-term Boltzmann equation to obtain the electro

  4. An efficient model for prediction of underwater noise due to pile driving at large ranges

    NARCIS (Netherlands)

    Nijhof, M.J.J.; Binnerts, B.; Jong, C.A.F. de; Ainslie, M.A.

    2014-01-01

    Modelling the sound levels in the water column due to pile driving operations nearby and out to large distances from the pile is crucial in assessing the likely impact on marine life. Standard numerical techniques for modelling the sound radiation from mechanical structures such as the finite elemen

  5. On Applications of Rasch Models in International Comparative Large-Scale Assessments: A Historical Review

    Science.gov (United States)

    Wendt, Heike; Bos, Wilfried; Goy, Martin

    2011-01-01

    Several current international comparative large-scale assessments of educational achievement (ICLSA) make use of "Rasch models", to address functions essential for valid cross-cultural comparisons. From a historical perspective, ICLSA and Georg Rasch's "models for measurement" emerged at about the same time, half a century ago. However, the…

  6. Estimation of leaf area for large scale phenotyping and modeling of rose genotypes

    NARCIS (Netherlands)

    Gao, M.; Heijden, van der G.W.A.M.; Vos, J.; Eveleens, B.A.; Marcelis, L.F.M.

    2012-01-01

    Leaf area is a major parameter in many physiological and plant modeling studies. When we want to use physiological models in plant breeding, we need to measure the leaf area for a large number of genotypes. This requires a fast and non-destructive method. In this study, we investigated whether for c

  7. Large-time behaviour of some fully discrete kinetic models in bounded domains

    Directory of Open Access Journals (Sweden)

    Ester Gabetta

    1991-05-01

    Full Text Available We investigate the large-time behaviour of the fully discretized version both of the three velocity Broadwell model and of the four velocity model in a strip. We analyze the different behaviours on the light of some recent results by M. Slemrod [7] and C. Cercignani [3].

  8. Evaluation of drought propagation in an ensemble mean of large-scale hydrological models

    Directory of Open Access Journals (Sweden)

    A. F. Van Loon

    2012-07-01

    Full Text Available Hydrological drought is increasingly studied using large-scale models. It is, however, not sure whether large-scale models reproduce the development of hydrological drought correctly. The pressing question is: how well do large-scale models simulate the propagation from meteorological to hydrological drought? To answer this question, we evaluated the simulation of drought propagation in an ensemble mean of ten large-scale models, both land-surface models and global hydrological models, that were part of the model intercomparison project of WATCH (WaterMIP. For a selection of case study areas, we studied drought characteristics (number of droughts, duration, severity, drought propagation features (pooling, attenuation, lag, lengthening, and hydrological drought typology (classical rainfall deficit drought, rain-to-snow-season drought, wet-to-dry-season drought, cold snow season drought, warm snow season drought, composite drought.

    Drought characteristics simulated by large-scale models clearly reflected drought propagation, i.e. drought events became less and longer when moving through the hydrological cycle. However, more differentiation was expected between fast and slowly responding systems, with slowly responding systems having less and longer droughts in runoff than fast responding systems. This was not found using large-scale models. Drought propagation features were poorly reproduced by the large-scale models, because runoff reacted immediately to precipitation, in all case study areas. This fast reaction to precipitation, even in cold climates in winter and in semi-arid climates in summer, also greatly influenced the hydrological drought typology as identified by the large-scale models. In general, the large-scale models had the correct representation of drought types, but the percentages of occurrence had some important mismatches, e.g. an overestimation of classical rainfall deficit droughts, and an

  9. Physically-consistent subgrid-scale models for large-eddy simulation of incompressible turbulent flows

    CERN Document Server

    Silvis, Maurits H

    2015-01-01

    Assuming a general constitutive relation for the turbulent stresses in terms of the local large-scale velocity gradient, we constructed a class of subgrid-scale models for large-eddy simulation that are consistent with important physical and mathematical properties. In particular, they preserve symmetries of the Navier-Stokes equations and exhibit the proper near-wall scaling. They furthermore show desirable dissipation behavior and are capable of describing nondissipative effects. We provided examples of such physically-consistent models and showed that existing subgrid-scale models do not all satisfy the desired properties.

  10. Large-scale modeling - a tool for conquering the complexity of the brain

    Directory of Open Access Journals (Sweden)

    Mikael Djurfeldt

    2008-04-01

    Full Text Available Is there any hope of achieving a thorough understanding of higher functions such as perception, memory, thought and emotion or is the stunning complexity of the brain a barrier which will limit such efforts for the foreseeable future? In this perspective we discuss methods to handle complexity, approaches to model building, and point to detailed large-scale models as a new contribution to the toolbox of the computational neuroscientist. We elucidate some aspects which distinguishes large-scale models and some of the technological challenges which they entail.

  11. Investigation on the integral output power model of a large-scale wind farm

    Institute of Scientific and Technical Information of China (English)

    BAO Nengsheng; MA Xiuqian; NI Weidou

    2007-01-01

    The integral output power model of a large-scale wind farm is needed when estimating the wind farm's output over a period of time in the future.The actual wind speed power model and calculation method of a wind farm made up of many wind turbine units are discussed.After analyzing the incoming wind flow characteristics and their energy distributions,and after considering the multi-effects among the wind turbine units and certain assumptions,the incoming wind flow model of multi-units is built.The calculation algorithms and steps of the integral output power model of a large-scale wind farm are provided.Finally,an actual power output of the wind farm is calculated and analyzed by using the practical measurement wind speed data.The characteristics of a large-scale wind farm are also discussed.

  12. Finite element modeling and analysis of piezo-integrated composite structures under large applied electric fields

    Science.gov (United States)

    Rao, M. N.; Tarun, S.; Schmidt, R.; Schröder, K.-U.

    2016-05-01

    In this article, we focus on static finite element (FE) simulation of piezoelectric laminated composite plates and shells, considering the nonlinear constitutive behavior of piezoelectric materials under large applied electric fields. Under the assumptions of small strains and large electric fields, the second-order nonlinear constitutive equations are used in the variational principle approach, to develop a nonlinear FE model. Numerical simulations are performed to study the effect of material nonlinearity for piezoelectric bimorph and laminated composite plates as well as cylindrical shells. In comparison to the experimental investigations existing in the literature, the results predicted by the present model agree very well. The importance of the present nonlinear model is highlighted especially in large applied electric fields, and it is shown that the difference between the results simulated by linear and nonlinear constitutive FE models cannot be omitted.

  13. Biomembrane models and drug-biomembrane interaction studies: Involvement in drug design and development

    Directory of Open Access Journals (Sweden)

    R Pignatello

    2011-01-01

    Full Text Available Contact with many different biological membranes goes along the destiny of a drug after its systemic administration. From the circulating macrophage cells to the vessel endothelium, to more complex absorption barriers, the interaction of a biomolecule with these membranes largely affects its rate and time of biodistribution in the body and at the target sites. Therefore, investigating the phenomena occurring on the cell membranes, as well as their different interaction with drugs in the physiological or pathological conditions, is important to exploit the molecular basis of many diseases and to identify new potential therapeutic strategies. Of course, the complexity of the structure and functions of biological and cell membranes, has pushed researchers toward the proposition and validation of simpler two- and three-dimensional membrane models, whose utility and drawbacks will be discussed. This review also describes the analytical methods used to look at the interactions among bioactive compounds with biological membrane models, with a particular accent on the calorimetric techniques. These studies can be considered as a powerful tool for medicinal chemistry and pharmaceutical technology, in the steps of designing new drugs and optimizing the activity and safety profile of compounds already used in the therapy.

  14. An ODE for an Overloaded X Model Involving a Stochastic Averaging Principle

    CERN Document Server

    Perry, Ohad

    2010-01-01

    We study an ordinary differential equation (ODE) arising as the many-server heavy-traffic fluid limit of a sequence of overloaded Markovian queueing models with two customer classes and two service pools. The system, known as the X model in the call-center literature, operates under the fixed-queue-ratio-with-thresholds (FQR-T) control, which we proposed in a recent paper as a way for one service system to help another in face of an unanticipated overload. Each pool serves only its own class until a threshold is exceeded; then one-way sharing is activated with all customer-server assignments then driving the two queues toward a fixed ratio. For large systems, that fixed ratio is achieved approximately. The ODE describes system performance during an overload. The control is driven by a queue-difference stochastic process, which operates in a faster time scale than the queueing processes themselves, thus achieving a time-dependent steady state instantaneously in the limit. As a result, for the ODE, the driving ...

  15. Modeling economic costs of disasters and recovery involving positive effects of reconstruction: analysis using a dynamic CGE model

    Directory of Open Access Journals (Sweden)

    W. Xie

    2013-11-01

    Full Text Available Disaster damages have negative effects on economy, whereas reconstruction investments have positive effects. The aim of this study is to model economic causes of disasters and recovery involving positive effects of reconstruction activities. Computable general equilibrium (CGE model is a promising approach because it can incorporate these two kinds of shocks into a unified framework and further avoid double-counting problem. In order to factor both shocks in CGE model, direct loss is set as the amount of capital stock reduced on supply side of economy; A portion of investments restore the capital stock in existing period; An investment-driven dynamic model is formulated due to available reconstruction data, and the rest of a given country's saving is set as an endogenous variable. The 2008 Wenchuan Earthquake is selected as a case study to illustrate the model, and three scenarios are constructed: S0 (no disaster occurs, S1 (disaster occurs with reconstruction investment and S2 (disaster occurs without reconstruction investment. S0 is taken as business as usual, and the differences between S1 and S0 and that between S2 and S0 can be interpreted as economic losses including reconstruction and excluding reconstruction respectively. The study showed that output from S1 is found to be closer to real data than that from S2. S2 overestimates economic loss by roughly two times that under S1. The gap in economic aggregate between S1 and S0 is reduced to 3% in 2011, a level that should take another four years to achieve under S2.

  16. Control-Oriented Model of Molar Scavenge Oxygen Fraction for Exhaust Recirculation in Large Diesel Engines

    DEFF Research Database (Denmark)

    Nielsen, Kræn Vodder; Blanke, Mogens; Eriksson, Lars

    2016-01-01

    therefore focus on deriving and validating a mean-value model of a large two-stroke crosshead diesel engines with EGR. The model introduces a number of amendments and extensions to previous, complex models and shows in theory and practice that a simplified nonlinear model captures all essential dynamics...... the behavior of the scavenge oxygen fraction well over the entire envelope of load and blower speed range that are relevant for EGR. The simplicity of the new model makes it suitable for observer and control design, which are essential steps to meet the emission requirements for marine diesel engines that take......Exhaust gas recirculation (EGR) systems have been introduced to large marine engines in order to reduce NOx formation. Adequate modelling for control design is one of the bottlenecks to design EGR control that also meets emission requirements during transient loading conditions. This paper...

  17. An improved temperature-dependent large signal model of microwave GaN HEMTs

    Science.gov (United States)

    Changsi, Wang; Yuehang, Xu; Zhang, Wen; Zhikai, Chen; Ruimin, Xu

    2016-07-01

    Accurate modeling of the electrothermal effects of GaN electronic devices is critical for reliability design and assessment. In this paper, an improved temperature-dependent model for large signal equivalent circuit modeling of GaN HEMTs is proposed. To accurately describe the thermal effects, a modified nonlinear thermal sub-circuit which is related not only to power dissipation, but also ambient temperature is used to calculate the variations of channel temperature of the device; the temperature-dependent parasitic and intrinsic elements are also taken into account in this model. The parameters of the thermal sub-circuit are extracted by using the numerical finite element method. The results show that better performance can be achieved by using the proposed large signal model in the range of -55 to 125 °C compared with the conventional model with a linear thermal sub-circuit. Project supported by the National Natural Science Foundation of China (No. 61106115).

  18. A dynamic subgrid-scale model for the large eddy simulation of stratified flow

    Institute of Scientific and Technical Information of China (English)

    刘宁宇; 陆夕云; 庄礼贤

    2000-01-01

    A new dynamic subgrid-scale (SGS) model, including subgrid turbulent stress and heat flux models for stratified shear flow is proposed by using Yoshizawa’ s eddy viscosity model as a base model. Based on our calculated results, the dynamic subgrid-scale model developed here is effective for the large eddy simulation (LES) of stratified turbulent channel flows. The new SGS model is then applied to the large eddy simulation of stratified turbulent channel flow under gravity to investigate the coupled shear and buoyancy effects on the near-wall turbulent statistics and the turbulent heat transfer at different Richardson numbers. The critical Richardson number predicted by the present calculation is in good agreement with the value of theoretical analysis.

  19. A dynamic subgrid-scale model for the large eddy simulation of stratified flow

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A new dynamic subgrid-scale (SGS) model, including subgrid turbulent stress and heat flux models for stratified shear flow is proposed by using Yoshizawa's eddy viscosity model as a base model. Based on our calculated results, the dynamic subgrid-scale model developed here is effective for the large eddy simulation (LES) of stratified turbulent channel flows. The new SGS model is then applied to the large eddy simulation of stratified turbulent channel flow under gravity to investigate the coupled shear and buoyancy effects on the near-wall turbulent statistics and the turbulent heat transfer at different Richardson numbers. The critical Richardson number predicted by the present calculation is in good agreement with the value of theoretical analysis.

  20. Large-Scale Forest Modeling: Deducing Stand Density from Inventory Data

    Directory of Open Access Journals (Sweden)

    Oskar Franklin

    2012-01-01

    Full Text Available While effects of thinning and natural disturbances on stand density play a central role for forest growth, their representation in large-scale studies is restricted by both model and data availability. Here a forest growth model was combined with a newly developed generic thinning model to estimate stand density and site productivity based on widely available inventory data (tree species, age class, volume, and increment. The combined model successfully coupled biomass, increment, and stand closure (=stand density/self-thinning limited stand density, as indicated by cross-validation against European-wide inventory data. The improvement in model performance attained by including variable stand closure among age cohorts compared to a fixed closure suggests that stand closure is an important parameter for accurate forest growth modeling also at large scales.

  1. Coupled Mesoscale-Large-Eddy Modeling of Realistic Stable Boundary Layer Turbulence

    CERN Document Server

    Wang, Yao; Manuel, Lance

    2013-01-01

    Site-specific flow and turbulence information are needed for various practical applications, ranging from aerodynamic/aeroelastic modeling for wind turbine design to optical diffraction calculations. Even though highly desirable, collecting on-site meteorological measurements can be an expensive, time-consuming, and sometimes a challenging task. In this work, we propose a coupled mesoscale-large-eddy modeling framework to synthetically generate site-specific flow and turbulence data. The workhorses behind our framework are a state-of-the-art, open-source atmospheric model called the Weather Research and Forecasting (WRF) model and a tuning-free large-eddy simulation (LES) model. Using this coupled framework, we simulate a nighttime stable boundary layer (SBL) case from the well-known CASES-99 field campaign. One of the unique aspects of this work is the usage of a diverse range of observations for characterization and validation. The coupled models reproduce certain characteristics of observed low-level jets....

  2. The Area Law in Matrix Models for Large N QCD Strings

    CERN Document Server

    Anagnostopoulos, K N; Nishimura, J

    2002-01-01

    We study the question whether matrix models obtained in the zero volume limit of 4d Yang-Mills theories can describe large N QCD strings. The matrix model we use is a variant of the Eguchi-Kawai model in terms of Hermitian matrices, but without any twists or quenching. This model was originally proposed as a toy model of the IIB matrix model. In contrast to common expectations, we do observe the area law for Wilson loops in a significant range of scale of the loop area. Numerical simulations show that this range is stable as N increases up to 768, which strongly suggests that it persists in the large N limit. Hence the equivalence to QCD strings may hold for length scales inside a finite regime.

  3. High total metabolic tumor volume in PET/CT predicts worse prognosis in diffuse large B cell lymphoma patients with bone marrow involvement in rituximab era.

    Science.gov (United States)

    Song, Moo-Kon; Yang, Deok-Hwan; Lee, Gyeong-Won; Lim, Sung-Nam; Shin, Seunghyeon; Pak, Kyoung June; Kwon, Seong Young; Shim, Hye Kyung; Choi, Bong-Hoi; Kim, In-Suk; Shin, Dong-Hoon; Kim, Seong-Geun; Oh, So-Yeon

    2016-03-01

    Bone marrow involvement (BMI) in diffuse large B cell lymphoma (DLBCL) was naively regarded as an adverse clinical factor. However, it has been unknown which factor would separate clinical outcomes in DLBCL patients with BMI. Recently, metabolic tumor volume (MTV) on positron emission tomography/computed tomography (PET/CT) was suggested to predict prognosis in several lymphoma types. Therefore, we investigated whether MTV would separate the outcomes in DLBCL patients with BMI. MTV on PET/CT was defined as an initial tumor burden as target lesion ≥ standard uptake value, 2.5 in 107 patients with BMI. Intramedullary (IM) MTV was defined as extent of BMI and total MTV was as whole tumor burden. 260.5 cm(3) and 601.2 cm(3) were ideal cut-off values for dividing high and low MTV status in the IM and total lymphoma lesions in Receiver Operating Curve analysis. High risk NCCN-IPI (phigh IM MTV status (phigh total MTV status (phigh risk NCCN-IPI (PFS, p=0.006; OS, p=0.013), concordant subtype (PFS, p=0.005; OS, p=0.007), and high total MTV status (PFS, p<0.001; OS, p<0.001) had independent clinical impacts. MTV had prognostic significances for survivals in DLBCL with BMI.

  4. Central nervous system involvement in diffuse large B-cell lymphoma: an analysis of risks and prevention strategies in the post-rituximab era.

    Science.gov (United States)

    Fletcher, Christopher D; Kahl, Brad S

    2014-10-01

    Central nervous system (CNS) relapse in patients with diffuse large B-cell lymphoma (DLBCL) occurs infrequently (approximately 5%), but is almost universally fatal. Controversy exists regarding which factors most reliably identify high risk patients in the post-rituximab era. Clarification is also needed regarding the value of prophylaxis strategies when contemporary rituximab-based chemotherapy regimens (chemoimmunotherapy) are used. A systematic review with focus on the era of chemoimmunotherapy has been performed. Involvement of > 1 extranodal site plus an elevated lactate dehydrogenase level identifies individuals at highest risk (> 20%) for CNS recurrence who merit additional evaluation. Only certain solitary extranodal sites (testis, kidney and breast, but not bones, orbit or epidural space) appear to confer higher risk in patients receiving chemoimmunotherapy. Data from studies employing modern regimens suggest that intrathecal prophylaxis is ineffective even for high risk populations. Systemic prophylaxis (e.g. high dose methotrexate) may be useful, but does not have strong support in the literature. A significant portion of patients with high risk features (˜25%) may already have subclinical CNS disease, which requires alternative detection and treatment strategies. Flow cytometry is a promising approach with increased sensitivity. Widespread use of this approach could redefine what risk and prophylaxis mean. An algorithm for incorporating risk factors, evaluation and treatment is presented.

  5. Precursory phenomena associated with large avalanches in the long-range connective sandpile (LRCS) model

    Science.gov (United States)

    Lee, Ya-Ting; Chen, Chien-chih; Chang, Young-Fo; Chiao, Ling-Yun

    2008-09-01

    Reduction in b-values before a large earthquake is a very popular topic for discussion. This study proposes an alternative sandpile model being able to demonstrate reduction in scaling exponents before large events through adaptable long-range connections. The distant connection between two separated cells was introduced in the sandpile model. We found that our modified long-range connective sandpile (LRCS) system repeatedly approaches and retreats from a critical state. When a large avalanche occurs in the LRCS model, accumulated energy dramatically dissipates and the system simultaneously retreats from criticality. The system quickly approaches the critical state accompanied by the increase in the slopes of the power-law frequency-size distributions of events. Afterwards, and most interestingly, the power-law slope declines before the next large event. The precursory b-value reduction before large earthquakes observed from earthquake catalogues closely mimics the evolution in power-law slopes for the frequency-size distributions of events derived in the LRCS models. Our paper, thus, provides a new explanation for declined b-values before large earthquakes.

  6. Deploying process modeling and attitude control of a satellite with a large deployable antenna

    OpenAIRE

    Zhigang Xing; Gangtie Zheng

    2014-01-01

    Modeling and attitude control methods for a satellite with a large deployable antenna are studied in the present paper. Firstly, for reducing the model dimension, three dynamic models for the deploying process are developed, which are built with the methods of multi-rigid-body dynamics, hybrid coordinate and substructure. Then an attitude control method suitable for the deploying process is proposed, which can keep stability under any dynamical parameter variation. Subsequently, this attitude...

  7. Modeling of the wave transmission properties of large arteries using nonlinear elastic tubes.

    Science.gov (United States)

    Pythoud, F; Stergiopulos, N; Meister, J J

    1994-11-01

    We propose a new, simple way of constructing elastic tubes which can be used to model the nonlinear elastic properties of large arteries. The tube models are constructed from a silicon elastomer (Sylgard 184, Dow Corning), which exhibits a nonlinear behavior with increased stiffness at high strains. Tests conducted on different tube models showed that, with the proper choice of geometric parameters, the elastic properties, in terms of area-pressure relation and compliance, can be similar to that of real arteries.

  8. "GRAY-BOX" MODELING METHOD AND PARAMETERS IDENTIFICATION FOR LARGE-SCALE HYDRAULIC SYSTEM

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Modeling and digital simulation is an effective method to analyze the dynamic characteristics of hydraulic system. It is difficult to determine some performance parameters in the hydraulic system by means of currently used modeling methods. The "gray-box" modeling method for large-scale hydraulic system is introduced. The principle of the method, the submodels of some components and the parameters identification of components or subsystem are researched.

  9. Simple Model for Simulating Characteristics of River Flow Velocity in Large Scale

    Directory of Open Access Journals (Sweden)

    Husin Alatas

    2015-01-01

    Full Text Available We propose a simple computer based phenomenological model to simulate the characteristics of river flow velocity in large scale. We use shuttle radar tomography mission based digital elevation model in grid form to define the terrain of catchment area. The model relies on mass-momentum conservation law and modified equation of motion of falling body in inclined plane. We assume inelastic collision occurs at every junction of two river branches to describe the dynamics of merged flow velocity.

  10. Distributed model of hydrological and sediment transport processes in large river basins in Southeast Asia

    Science.gov (United States)

    Zuliziana, S.; Tanuma, K.; Yoshimura, C.; Saavedra, O. C.

    2015-07-01

    Soil erosion and sediment transport have been modeled at several spatial and temporal scales, yet few models have been reported for large river basins (e.g., drainage areas > 100 000 km2). In this study, we propose a process-based distributed model for assessment of sediment transport at a large basin scale. A distributed hydrological model was coupled with a process-based distributed sediment transport model describing soil erosion and sedimentary processes at hillslope units and channels. The model was tested on two large river basins: the Chao Phraya River Basin (drainage area: 160 000 km2) and the Mekong River Basin (795 000 km2). The simulation over 10 years showed good agreement with the observed suspended sediment load in both basins. The average Nash-Sutcliffe efficiency (NSE) and average correlation coefficient (r) between the simulated and observed suspended sediment loads were 0.62 and 0.61, respectively, in the Chao Phraya River Basin except the lowland section. In the Mekong River Basin, the overall average NSE and r were 0.60 and 0.78, respectively. Sensitivity analysis indicated that suspended sediment load is sensitive to detachability by raindrop (k) in the Chao Phraya River Basin and to soil detachability over land (Kf) in the Mekong River Basin. Overall, the results suggest that the present model can be used to understand and simulate erosion and sediment transport in large river basins.

  11. Distributed model of hydrological and sediment transport processes in large river basins in Southeast Asia

    Directory of Open Access Journals (Sweden)

    S. Zuliziana

    2015-07-01

    Full Text Available Soil erosion and sediment transport have been modeled at several spatial and temporal scales, yet few models have been reported for large river basins (e.g., drainage areas > 100 000 km2. In this study, we propose a process-based distributed model for assessment of sediment transport at a large basin scale. A distributed hydrological model was coupled with a process-based distributed sediment transport model describing soil erosion and sedimentary processes at hillslope units and channels. The model was tested on two large river basins: the Chao Phraya River Basin (drainage area: 160 000 km2 and the Mekong River Basin (795 000 km2. The simulation over 10 years showed good agreement with the observed suspended sediment load in both basins. The average Nash–Sutcliffe efficiency (NSE and average correlation coefficient (r between the simulated and observed suspended sediment loads were 0.62 and 0.61, respectively, in the Chao Phraya River Basin except the lowland section. In the Mekong River Basin, the overall average NSE and r were 0.60 and 0.78, respectively. Sensitivity analysis indicated that suspended sediment load is sensitive to detachability by raindrop (k in the Chao Phraya River Basin and to soil detachability over land (Kf in the Mekong River Basin. Overall, the results suggest that the present model can be used to understand and simulate erosion and sediment transport in large river basins.

  12. A Nonlinear k-ε Turbulence Model Applicable to High Pressure Gradient and Large Curvature Flow

    Directory of Open Access Journals (Sweden)

    Xiyao Gu

    2014-01-01

    Full Text Available Most of the RANS turbulence models solve the Reynolds stress by linear hypothesis with isotropic model. They can not capture all kinds of vortexes in the turbomachineries. In this paper, an improved nonlinear k-ε turbulence model is proposed, which is modified from the RNG k-ε turbulence model and Wilcox's k-ω turbulence model. The Reynolds stresses are solved by nonlinear methods. The nonlinear k-ε turbulence model can calculate the near wall region without the use of wall functions. The improved nonlinear k-ε turbulence model is used to simulate the flow field in a curved rectangular duct. The results based on the improved nonlinear k-ε turbulence model agree well with the experimental results. The calculation results prove that the nonlinear k-ε turbulence model is available for high pressure gradient flows and large curvature flows, and it can be used to capture complex vortexes in a turbomachinery.

  13. Numerical modelling of odour dispersion around a cubical obstacle using large eddy simulation.

    Science.gov (United States)

    Dourado, Harerton Oliveira; Santos, Jane Meri; Reis, Neyval C; Mavroidis, Ilias

    2012-01-01

    In the present work two different large eddy simulation (LES) approaches, namely the Dynamic Smagorinsky model and the Wale model, are used to simulate the air flow and pollutant dispersion around a cubical obstacle. Results are compared with wind tunnel data (WT) and with results from the Smagorinsky LES model. Overall agreement was good between the different LES approaches and the WT results, both for the mean and fluctuating flow and concentration patterns. LES models can provide good estimates of concentration fluctuation intensity and enable the calculation of the intermittency factor. The model results indicate that LES is a viable tool for odour impact assessment.

  14. An integrated model for assessing both crop productivity and agricultural water resources at a large scale

    Science.gov (United States)

    Okada, M.; Sakurai, G.; Iizumi, T.; Yokozawa, M.

    2012-12-01

    Agricultural production utilizes regional resources (e.g. river water and ground water) as well as local resources (e.g. temperature, rainfall, solar energy). Future climate changes and increasing demand due to population increases and economic developments would intensively affect the availability of water resources for agricultural production. While many studies assessed the impacts of climate change on agriculture, there are few studies that dynamically account for changes in water resources and crop production. This study proposes an integrated model for assessing both crop productivity and agricultural water resources at a large scale. Also, the irrigation management to subseasonal variability in weather and crop response varies for each region and each crop. To deal with such variations, we used the Markov Chain Monte Carlo technique to quantify regional-specific parameters associated with crop growth and irrigation water estimations. We coupled a large-scale crop model (Sakurai et al. 2012), with a global water resources model, H08 (Hanasaki et al. 2008). The integrated model was consisting of five sub-models for the following processes: land surface, crop growth, river routing, reservoir operation, and anthropogenic water withdrawal. The land surface sub-model was based on a watershed hydrology model, SWAT (Neitsch et al. 2009). Surface and subsurface runoffs simulated by the land surface sub-model were input to the river routing sub-model of the H08 model. A part of regional water resources available for agriculture, simulated by the H08 model, was input as irrigation water to the land surface sub-model. The timing and amount of irrigation water was simulated at a daily step. The integrated model reproduced the observed streamflow in an individual watershed. Additionally, the model accurately reproduced the trends and interannual variations of crop yields. To demonstrate the usefulness of the integrated model, we compared two types of impact assessment of

  15. Development of models and methods for the molecular simulation of large systems and molecules

    CERN Document Server

    Walter, Jonathan; Horsch, Martin; Vrabec, Jadran; Hasse, Hans

    2010-01-01

    The most important factor for quantitative results in molecular dynamics simulation are well developed force fields and models. In the present work, the development of new models and the usage of force fields from the literature in large systems are presented. Both tasks lead to time consuming simulations that require massively parallel high performance computing. In the present work, new models for carbon dioxide and cyclohexanolare discussed and a new method for the model development is introduced. Force fields and models for the simulation of PNIPAAm hydrogel in pure water and sodium chloride solution are tested and verified and applied to the simulation of nucleation processes.

  16. Large magnetic cooling power involving frustrated antiferromagnetic spin-glass state in R2NiSi3(R =Gd ,Er )

    Science.gov (United States)

    Pakhira, Santanu; Mazumdar, Chandan; Ranganathan, R.; Giri, S.; Avdeev, Maxim

    2016-09-01

    The ternary intermetallic compounds Gd2NiSi3 and Er2NiSi3 are synthesized in chemically single phase, which are characterized using dc magnetization, ac magnetic susceptibility, heat capacity, and neutron diffraction studies. Neutron diffraction and heat capacity studies confirm that long-range magnetic ordering coexists with the frustrated glassy magnetic components for both compounds. The static and dynamical features of dc magnetization and frequency-dependent ac susceptibility data reveal that Gd2NiSi3 is a canonical spin-glass system, while Er2NiSi3 is a reentrant spin cluster-glass system. The spin freezing temperature merges with the long-range antiferromagnetic ordering temperature at 16.4 K for Gd2NiSi3 . Er2NiSi3 undergoes antiferromagnetic ordering at 5.4 K, which is slightly above the spin freezing temperature at 3 K. The detailed studies of nonequilibrium dynamical behavior, viz., the memory effect and relaxation behavior using different protocols, suggest that both compounds favor the hierarchical model over the droplet model. A large magnetocaloric effect is observed for both compounds. Maximum values of isothermal entropy change (-Δ SM ) and relative cooling power (RCP) are found to be 18.4 J/kg K and 525 J/kg for Gd2NiSi3 and 22.6 J/kg K and 540 J/kg for Er2NiSi3 , respectively, for a change in field from 0 to 70 kOe. The values of RCP are comparable to those of the promising refrigerant materials. A correlation between large RCP and magnetic frustration is discussed for developing new magnetic refrigerant materials.

  17. Large-scale hydrology in Europe : observed patterns and model performance

    Energy Technology Data Exchange (ETDEWEB)

    Gudmundsson, Lukas

    2011-06-15

    In a changing climate, terrestrial water storages are of great interest as water availability impacts key aspects of ecosystem functioning. Thus, a better understanding of the variations of wet and dry periods will contribute to fully grasp processes of the earth system such as nutrient cycling and vegetation dynamics. Currently, river runoff from small, nearly natural, catchments is one of the few variables of the terrestrial water balance that is regularly monitored with detailed spatial and temporal coverage on large scales. River runoff, therefore, provides a foundation to approach European hydrology with respect to observed patterns on large scales, with regard to the ability of models to capture these.The analysis of observed river flow from small catchments, focused on the identification and description of spatial patterns of simultaneous temporal variations of runoff. These are dominated by large-scale variations of climatic variables but also altered by catchment processes. It was shown that time series of annual low, mean and high flows follow the same atmospheric drivers. The observation that high flows are more closely coupled to large scale atmospheric drivers than low flows, indicates the increasing influence of catchment properties on runoff under dry conditions. Further, it was shown that the low-frequency variability of European runoff is dominated by two opposing centres of simultaneous variations, such that dry years in the north are accompanied by wet years in the south.Large-scale hydrological models are simplified representations of our current perception of the terrestrial water balance on large scales. Quantification of the models strengths and weaknesses is the prerequisite for a reliable interpretation of simulation results. Model evaluations may also enable to detect shortcomings with model assumptions and thus enable a refinement of the current perception of hydrological systems. The ability of a multi model ensemble of nine large

  18. Large-watershed flood forecasting with high-resolution distributed hydrological model

    Science.gov (United States)

    Chen, Yangbo; Li, Ji; Wang, Huanyu; Qin, Jianming; Dong, Liming

    2017-02-01

    A distributed hydrological model has been successfully used in small-watershed flood forecasting, but there are still challenges for the application in a large watershed, one of them being the model's spatial resolution effect. To cope with this challenge, two efforts could be made; one is to improve the model's computation efficiency in a large watershed, the other is implementing the model on a high-performance supercomputer. This study sets up a physically based distributed hydrological model for flood forecasting of the Liujiang River basin in south China. Terrain data digital elevation model (DEM), soil and land use are downloaded from the website freely, and the model structure with a high resolution of 200 m × 200 m grid cell is set up. The initial model parameters are derived from the terrain property data, and then optimized by using the Particle Swarm Optimization (PSO) algorithm; the model is used to simulate 29 observed flood events. It has been found that by dividing the river channels into virtual channel sections and assuming the cross section shapes as trapezoid, the Liuxihe model largely increases computation efficiency while keeping good model performance, thus making it applicable in larger watersheds. This study also finds that parameter uncertainty exists for physically deriving model parameters, and parameter optimization could reduce this uncertainty, and is highly recommended. Computation time needed for running a distributed hydrological model increases exponentially at a power of 2, not linearly with the increasing of model spatial resolution, and the 200 m × 200 m model resolution is proposed for modeling the Liujiang River basin flood with the Liuxihe model in this study. To keep the model with an acceptable performance, minimum model spatial resolution is needed. The suggested threshold model spatial resolution for modeling the Liujiang River basin flood is a 500 m × 500 m grid cell, but the model spatial resolution with a 200 m

  19. Expression profiles of genes involved in xenobiotic metabolism and disposition in human renal tissues and renal cell models

    Energy Technology Data Exchange (ETDEWEB)

    Van der Hauwaert, Cynthia; Savary, Grégoire [EA4483, Université de Lille 2, Faculté de Médecine de Lille, Pôle Recherche, 59045 Lille (France); Buob, David [Institut de Pathologie, Centre de Biologie Pathologie Génétique, Centre Hospitalier Régional Universitaire de Lille, 59037 Lille (France); Leroy, Xavier; Aubert, Sébastien [Institut de Pathologie, Centre de Biologie Pathologie Génétique, Centre Hospitalier Régional Universitaire de Lille, 59037 Lille (France); Institut National de la Santé et de la Recherche Médicale, UMR837, Centre de Recherche Jean-Pierre Aubert, Equipe 5, 59045 Lille (France); Flamand, Vincent [Service d' Urologie, Hôpital Huriez, Centre Hospitalier Régional Universitaire de Lille, 59037 Lille (France); Hennino, Marie-Flore [EA4483, Université de Lille 2, Faculté de Médecine de Lille, Pôle Recherche, 59045 Lille (France); Service de Néphrologie, Hôpital Huriez, Centre Hospitalier Régional Universitaire de Lille, 59037 Lille (France); Perrais, Michaël [Institut National de la Santé et de la Recherche Médicale, UMR837, Centre de Recherche Jean-Pierre Aubert, Equipe 5, 59045 Lille (France); and others

    2014-09-15

    Numerous xenobiotics have been shown to be harmful for the kidney. Thus, to improve our knowledge of the cellular processing of these nephrotoxic compounds, we evaluated, by real-time PCR, the mRNA expression level of 377 genes encoding xenobiotic-metabolizing enzymes (XMEs), transporters, as well as nuclear receptors and transcription factors that coordinate their expression in eight normal human renal cortical tissues. Additionally, since several renal in vitro models are commonly used in pharmacological and toxicological studies, we investigated their metabolic capacities and compared them with those of renal tissues. The same set of genes was thus investigated in HEK293 and HK2 immortalized cell lines in commercial primary cultures of epithelial renal cells and in proximal tubular cell primary cultures. Altogether, our data offers a comprehensive description of kidney ability to process xenobiotics. Moreover, by hierarchical clustering, we observed large variations in gene expression profiles between renal cell lines and renal tissues. Primary cultures of proximal tubular epithelial cells exhibited the highest similarities with renal tissue in terms of transcript profiling. Moreover, compared to other renal cell models, Tacrolimus dose dependent toxic effects were lower in proximal tubular cell primary cultures that display the highest metabolism and disposition capacity. Therefore, primary cultures appear to be the most relevant in vitro model for investigating the metabolism and bioactivation of nephrotoxic compounds and for toxicological and pharmacological studies. - Highlights: • Renal proximal tubular (PT) cells are highly sensitive to xenobiotics. • Expression of genes involved in xenobiotic disposition was measured. • PT cells exhibited the highest similarities with renal tissue.

  20. Involvement of Autophagic Pathway in the Progression of Retinal Degeneration in a Mouse Model of Diabetes.

    Science.gov (United States)

    Piano, Ilaria; Novelli, Elena; Della Santina, Luca; Strettoi, Enrica; Cervetto, Luigi; Gargini, Claudia

    2016-01-01

    The notion that diabetic retinopathy (DR) is essentially a micro-vascular disease has been recently challenged by studies reporting that vascular changes are preceded by signs of damage and loss of retinal neurons. As to the mode by which neuronal death occurs, the evidence that apoptosis is the main cause of neuronal loss is far from compelling. The objective of this study was to investigate these controversies in a mouse model of streptozotocin (STZ) induced diabetes. Starting from 8 weeks after diabetes induction there was loss of rod but not of cone photoreceptors, together with reduced thickness of the outer and inner synaptic layers. Correspondingly, rhodopsin expression was downregulated and the scotopic electroretinogram (ERG) is suppressed. In contrast, cone opsin expression and photopic ERG response were not affected. Suppression of the scotopic ERG preceded morphological changes as well as any detectable sign of vascular alteration. Only sparse apoptotic figures were detected by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay and glia was not activated. The physiological autophagy flow was altered instead, as seen by increased LC3 immunostaining at the level of outer plexiform layer (OPL) and upregulation of the autophagic proteins Beclin-1 and Atg5. Collectively, our results show that the streptozotocin induced DR in mouse initiates with a functional loss of the rod visual pathway. The pathogenic pathways leading to cell death develop with the initial dysregulation of autophagy well before the appearance of signs of vascular damage and without strong involvement of apoptosis.