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Sample records for model uncovers dual

  1. Dual-Schemata Model

    Science.gov (United States)

    Taniguchi, Tadahiro; Sawaragi, Tetsuo

    In this paper, a new machine-learning method, called Dual-Schemata model, is presented. Dual-Schemata model is a kind of self-organizational machine learning methods for an autonomous robot interacting with an unknown dynamical environment. This is based on Piaget's Schema model, that is a classical psychological model to explain memory and cognitive development of human beings. Our Dual-Schemata model is developed as a computational model of Piaget's Schema model, especially focusing on sensori-motor developing period. This developmental process is characterized by a couple of two mutually-interacting dynamics; one is a dynamics formed by assimilation and accommodation, and the other dynamics is formed by equilibration and differentiation. By these dynamics schema system enables an agent to act well in a real world. This schema's differentiation process corresponds to a symbol formation process occurring within an autonomous agent when it interacts with an unknown, dynamically changing environment. Experiment results obtained from an autonomous facial robot in which our model is embedded are presented; an autonomous facial robot becomes able to chase a ball moving in various ways without any rewards nor teaching signals from outside. Moreover, emergence of concepts on the target movements within a robot is shown and discussed in terms of fuzzy logics on set-subset inclusive relationships.

  2. Dual-resonance models

    International Nuclear Information System (INIS)

    Mandelstam, S.

    1976-01-01

    Most models of theories of so-called elementary particles start from systems containing a finite number of kinds of such particles. This is true whether one works within the framework of quantum field theory, with a finite number of fields, or of S-matrix theory, where one neglects all but a finite number of particles in the unitarity condition. The concept of a Regge trajectory suggests the possibility of a more general scheme, but most conventional S-matrix models which attempt to predict the position of Regge trajectories neglect all but a finite number of particles. (Auth.)

  3. Vacuum transitions in dual models

    International Nuclear Information System (INIS)

    Pashnev, A.I.; Volkov, D.V.; Zheltukhin, A.A.

    1976-01-01

    The investigation is continued of the spontaneous vacuum transition problem in the Neview-Schwartz dual model (NSDM). It is shown that vacuum transitions allow disclosing of supplementary degeneration in the resonance state spectrum. The dual amplitudes possess an internal structure corresponding to the presence of an infinite number of quarks with increasing masses and retained charges. The Adler principle holds. Analytic continuation on the constant of induced vacuum transitions makes it possible to establish the existence of spontaneous vacuum transitions in the NSDM. The consequence of this fact is the exact SU(2) symmetry of π, rho meson trajectories and the Higgs mechanism in the model. In this case the ratios of masses of particles leading trajectories are analogous to those obtained in the current algebra. It is shown that in the NSDM there arises chiral SU(2) x SU(2) x U(1) x U(1) x ... symmetry resulting from spontaneous vacuum transitions

  4. Modelling of the liquid level during uncovering of the TMI-2 core

    International Nuclear Information System (INIS)

    Ardron, K.H.; Cain, D.G.

    1980-01-01

    Calculation of the path followed by the falling liquid level in the core is an important part of the analysis of fuel heat-up, and the damage sustained in the accident at TMI-2. This paper describes the development and application of a model for predicting liquid level in the TMI-2 core during uncovering. The calculational method is shown to give a satisfactory representation of level height data obtained in TMI boil-down simulation tests in the Semi-scale facility. The model is combined with a best estimate of make-up flow to the TMI-2 core to calculate the level trajectory during core uncovering. Results are found to be sensitive to the assumed degree of steam condensation on the make-up flow

  5. Dual-code quantum computation model

    Science.gov (United States)

    Choi, Byung-Soo

    2015-08-01

    In this work, we propose the dual-code quantum computation model—a fault-tolerant quantum computation scheme which alternates between two different quantum error-correction codes. Since the chosen two codes have different sets of transversal gates, we can implement a universal set of gates transversally, thereby reducing the overall cost. We use code teleportation to convert between quantum states in different codes. The overall cost is decreased if code teleportation requires fewer resources than the fault-tolerant implementation of the non-transversal gate in a specific code. To analyze the cost reduction, we investigate two cases with different base codes, namely the Steane and Bacon-Shor codes. For the Steane code, neither the proposed dual-code model nor another variation of it achieves any cost reduction since the conventional approach is simple. For the Bacon-Shor code, the three proposed variations of the dual-code model reduce the overall cost. However, as the encoding level increases, the cost reduction decreases and becomes negative. Therefore, the proposed dual-code model is advantageous only when the encoding level is low and the cost of the non-transversal gate is relatively high.

  6. Dual superconductor models of color confinement

    CERN Document Server

    Ripka, Georges

    2004-01-01

    The lectures, delivered at ECT (European Centre for Theoretical Studies in Nuclear Physics and Related Areas) in Trento (Italy) in 2002 and 2003, are addressed to physicists who wish to acquire a minimal background to understand present day attempts to model the confinement of quantum chromo-dynamics (QCD) in terms of dual superconductors. The lectures focus more on the models than on attempts to derive them from QCD. They discuss the Dirac theory of magnetic monopoles, the world sheet swept out by Dirac strings, deformations of Dirac strings and charge quantization, gauge fields associated to the field tensor and to the dual field tensor, the Landau-Ginzburg (Abelian Higgs) model of a dual superconductor, the flux tube joining two equal and opposite color-electric charges, the Abrikosov-Nielsen-Olesen vortex, the divergencies of the London limit, the comparison of the calculated flux tube and string tension with lattice data, duality transformations and the use of Kalb-Ramond fields, the two-potential Zwanzi...

  7. Numerical and model validation of uncovered nanofluid sheet and tube type photovoltaic thermal solar system

    International Nuclear Information System (INIS)

    Rejeb, Oussama; Sardarabadi, Mohammad; Ménézo, Christophe; Passandideh-Fard, Mohammad; Dhaou, Mohamed Houcine; Jemni, Abdelmajid

    2016-01-01

    Highlights: • A numerical model applied to analyze an uncovered nanofluid based PVT collector. • The model included nanoparticle concentration, types and different base fluids. • Numerical model are performed on Al 2 O 3 and CuO nanoparticles (1, 2 and 4 wt %). - Abstract: In this paper, an experimental and numerical study is performed to evaluate the performance of a photovoltaic thermal (PV/T) nanofluid based collector. A two-dimensional numerical model is established to study the effects of using nanofluids as working fluid in PV/T collector. The model is validated experimentally by comparing the simulations with the experimental results. The influence of concentration (0.1, 0.2 and 0.4 wt.%), types of nanoparticles (Al 2 O 3 and Cu) and different base fluids (pure water and ethylene glycol) on the electrical and thermal performance of the collector is investigated. Also, the model is applied to predict the annual electrical and thermal output of the PV/T for three different cities: Lyon (France), Mashhad (Iran) and Monastir (Tunisia). The results indicated that using pure water as a base fluid provides a higher performance in comparison with ethylene glycol. Using Cu/water gives the best thermal and electrical efficiency in comparison to Cu/ethylene glycol, Al 2 O 3 /water and Al 2 O 3 /ethylene glycol. It is also found that the thermal and electrical energy output for Monastir (Tunisia) climate condition is higher than that of Mashhad (Iran) and Lyon (France).

  8. The dual of the Carroll-Field-Jackiw model

    International Nuclear Information System (INIS)

    Guimaraes, M.S.; Grigorio, L.; Wotzasek, C.

    2006-01-01

    In this work we apply different duality techniques, both the dual projection, based on the soldering formalism and the master action, in order to obtain and study the dual description of the Carroll- Field-Jackiw model [1], a theory with a Chern-Simons-like explicitly Lorentz and CPT violating term, including the interaction with external charges. This Maxwell-Chern-Simons-like model may be rewritten in terms of the interacting modes of a massless scalar model and a topologically massive model [2], that are mapped, through duality, into interacting massless Maxwell and massive self-dual modes [3]. It is also shown that these dual modes might be represented into an unified rank-two self-dual model that represents the direct dual of the vector Maxwell-Chern-Simons-like model

  9. Dual Enrollment in Spanish: One Working Model

    Science.gov (United States)

    Bloom, Melanie; Chambers, Laura

    2009-01-01

    Dual enrollment is now a nation-wide phenomenon as all 50 states currently offer some form of dual-enrollment program to secondary-school students (Karp, Bailey, Hughes, and Fermin 2005). However, dual enrollment itself is often difficult to define as programs vary from school to school (Jordan, Cavalluzzo, and Corallo 2006). Therefore, language…

  10. Dual models with SL(2, C) symmetry

    CERN Document Server

    Brink, L

    1972-01-01

    Making use of homogeneous space techniques, the authors construct a class of dual models, which is a generalization of the Virasoro- Shapiro type of model. The integrand in the integral representation for the N-point function depends not only on the modulus of the distances between two-dimensional Koba-Nielsen variables, but also on the corresponding phases. This is in fact the most general SL(2, C) invariant amplitude that can be constructed using complex integration variables. The extra phase factors in the integrand provide a possible means of avoiding tachyons both as external particles and as intermediate states in the amplitude. When factorized in a simple- minded fashion the intercepts are fixed to be integers. Although the external particles can be chosen not to be tachyons, such states appear as intermediate states. Within this factorization one can show that there are gauge conditions for the amplitude that can provide a ghostkilling mechanism. (19 refs).

  11. Dual Numbers Approach in Multiaxis Machines Error Modeling

    Directory of Open Access Journals (Sweden)

    Jaroslav Hrdina

    2014-01-01

    Full Text Available Multiaxis machines error modeling is set in the context of modern differential geometry and linear algebra. We apply special classes of matrices over dual numbers and propose a generalization of such concept by means of general Weil algebras. We show that the classification of the geometric errors follows directly from the algebraic properties of the matrices over dual numbers and thus the calculus over the dual numbers is the proper tool for the methodology of multiaxis machines error modeling.

  12. The dual model of perfectionism and depression among Chinese ...

    African Journals Online (AJOL)

    The dual model of perfectionism was adopted to explore the influence of adaptive and maladaptive perfectionism on depression in college students. The results support the dual process model of perfectionism in Chinese undergraduates. A sample of 206 Chinese undergraduates completed measures of perfectionism, ...

  13. Digging through model complexity: using hierarchical models to uncover evolutionary processes in the wild.

    Science.gov (United States)

    Buoro, M; Prévost, E; Gimenez, O

    2012-10-01

    The growing interest for studying questions in the wild requires acknowledging that eco-evolutionary processes are complex, hierarchically structured and often partially observed or with measurement error. These issues have long been ignored in evolutionary biology, which might have led to flawed inference when addressing evolutionary questions. Hierarchical modelling (HM) has been proposed as a generic statistical framework to deal with complexity in ecological data and account for uncertainty. However, to date, HM has seldom been used to investigate evolutionary mechanisms possibly underlying observed patterns. Here, we contend the HM approach offers a relevant approach for the study of eco-evolutionary processes in the wild by confronting formal theories to empirical data through proper statistical inference. Studying eco-evolutionary processes requires considering the complete and often complex life histories of organisms. We show how this can be achieved by combining sequentially all life-history components and all available sources of information through HM. We demonstrate how eco-evolutionary processes may be poorly inferred or even missed without using the full potential of HM. As a case study, we use the Atlantic salmon and data on wild marked juveniles. We assess a reaction norm for migration and two potential trade-offs for survival. Overall, HM has a great potential to address evolutionary questions and investigate important processes that could not previously be assessed in laboratory or short time-scale studies. © 2012 The Authors. Journal of Evolutionary Biology © 2012 European Society For Evolutionary Biology.

  14. Dual model of vocational education: Austrian example

    Directory of Open Access Journals (Sweden)

    Tomić Milica

    2015-01-01

    Full Text Available Dual education, as a form of secondary vocational education means that education and practical training are held on two locations - in school and in a company (organization, factory and that these two institutions jointly participate in the realization of vocational education. The paper presents an account of the functioning of dual education in Austria. In that framework special attention was paid to law regulations in this field, the modes of dual education, progression through the system and the perspectives of the young in the labour market. Among the key features of dual education which are, at the same time, considered the factors of its successfulness, the following stand out: active role of social partners in the conceptualization and realization of vocational education; intensive practical training of high quality; systemic interrelatedness of vocational schools and firms where practical training is provided, the compliance of the offer of educational profiles and the needs of labour market; the system of stimulation for the firms that provide professional training for students, clear legislation and the system of professional qualifications. Yet, the challenges of dual educations are not neglected in the paper.

  15. Establishment of animal model of dual liver transplantation in rat.

    Directory of Open Access Journals (Sweden)

    Ying Zhang

    Full Text Available The animal model of the whole-size and reduced-size liver transplantation in both rat and mouse has been successfully established. Because of the difficulties and complexities in microsurgical technology, the animal model of dual liver transplantation was still not established for twelve years since the first human dual liver transplantation has been made a success. There is an essential need to establish this animal model to lay a basic foundation for clinical practice. To study the physiological and histopathological changes of dual liver transplantation, "Y" type vein from the cross part between vena cava and two iliac of donor and "Y' type prosthesis were employed to recanalize portal vein and the bile duct between dual liver grafts and recipient. The dual right upper lobes about 45-50% of the recipient liver volume were taken as donor, one was orthotopically implanted at its original position, the other was rotated 180° sagitally and heterotopically positioned in the left upper quadrant. Microcirculation parameters, liver function, immunohistochemistry and survival were analyzed to evaluate the function of dual liver grafts. No significant difference in the hepatic microcirculatory flow was found between two grafts in the first 90 minutes after reperfusion. Light and electronic microscope showed the liver architecture was maintained without obvious features of cellular destruction and the continuity of the endothelium was preserved. Only 3 heterotopically positioned graft appeared patchy desquamation of endothelial cell, mitochondrial swelling and hepatocytes cytoplasmic vacuolization. Immunohistochemistry revealed there is no difference in hepatocyte activity and the ability of endothelia to contract and relax after reperfusion between dual grafts. Dual grafts made a rapid amelioration of liver function after reperfusion. 7 rats survived more than 7 days with survival rate of 58.3.%. Using "Y" type vein and bile duct prosthesis, we

  16. Distributed Model Predictive Control via Dual Decomposition

    DEFF Research Database (Denmark)

    Biegel, Benjamin; Stoustrup, Jakob; Andersen, Palle

    2014-01-01

    . This allows coordination of all the subsystems without the need of sharing local dynamics, objectives and constraints. To illustrate this, an example is included where dual decomposition is used to resolve power grid congestion in a distributed manner among a number of players coupled by distribution grid...

  17. Dual energy CT. Physical models and applications

    International Nuclear Information System (INIS)

    Sedlmair, Martin Ulrich

    2010-01-01

    Computer tomography (CT) is today a very important non-invasive imaging tool for medical diagnostics. Despite the non-negligible radiation doses of patients and medical personal certain diagnostic questions can only be answered using CT methods. Recent developments adding a second radiation source and a second detector (dual-source CT) allow the imaging the heart beat due to an improved acquisition time. Operation of the X-ray tubes with different voltages (dual-energy) and appropriate data processing methods allow extended information on the tissue composition, pathological structures and improved visualization of lesions. The contribution covers the basic physical background of this technology and is focused on applications, as for instance CT-guided angiography.

  18. An extended dual search space model of scientific discovery learning

    NARCIS (Netherlands)

    van Joolingen, Wouter; de Jong, Anthonius J.M.

    1997-01-01

    This article describes a theory of scientific discovery learning which is an extension of Klahr and Dunbar''s model of Scientific Discovery as Dual Search (SDDS) model. We present a model capable of describing and understanding scientific discovery learning in complex domains in terms of the SDDS

  19. On the quark structure of resonance states in dual models

    International Nuclear Information System (INIS)

    Volkov, D.V.; Zheltukhin, A.A.; Pashnev, A.I.

    1975-01-01

    It is shown using as an example the Veneziano dual model, that each particular dual model already contains a certain latent quark structure unambiauously determined by internal properties of the dual model. To prove this degeneration of the resonance state spectrum is studied by introducing an additional disturbing interaction into the model being considered. Induced transitions of particles into a vacuum act as such an additional disturbance. This method complements the known factorization method of Fubini, Gordon and Veneziano and turns out to be free from an essential limitation of the latter connected with implicit assumption about the basence of internal additive laws of conservation in the model. By using the method of induced transitions of particles into a vacuum it has been possible to show that the resonance state spectrum is indeed more degenerated than it should be expected from the factorization theorem, and that the supplementary degeneration corresponds to the quark model with an infinite number of quarks of the increasing mass. Structures of some terms of the dual amplitude expansion over the degrees of the constant of the induced transition of particles to vacuum are considered; it is shown that the summation of this expansion may be reduced to a solution of a certain integral equation. On the basis of the integral equation obtained an integral representation ofr dual amplitudes is established. The problems related with degeneration of resonance states and with determination of additive quantum numbers leading to the quark interpretation of the degeneration being considered are discussed

  20. A dual model approach to ground water recovery trench design

    International Nuclear Information System (INIS)

    Clodfelter, C.L.; Crouch, M.S.

    1992-01-01

    The design of trenches for contaminated ground water recovery must consider several variables. This paper presents a dual-model approach for effectively recovering contaminated ground water migrating toward a trench by advection. The approach involves an analytical model to determine the vertical influence of the trench and a numerical flow model to determine the capture zone within the trench and the surrounding aquifer. The analytical model is utilized by varying trench dimensions and head values to design a trench which meets the remediation criteria. The numerical flow model is utilized to select the type of backfill and location of sumps within the trench. The dual-model approach can be used to design a recovery trench which effectively captures advective migration of contaminants in the vertical and horizontal planes

  1. 3D modeling of dual wind-up extensional rheometers

    DEFF Research Database (Denmark)

    Yu, Kaijia; Román Marín, José Manuel; Rasmussen, Henrik K.

    2010-01-01

    Fully three-dimensional numerical simulations of a dual wind-up drum rheometer of the Sentmanat Extensional Rheometer (SER; Sentmanat, 2004 [1]) or the Extensional Viscosity Fixture (EVF; Garritano and Berting, 2006 [2]) type have been performed. In the SER and EVF a strip of rectangular shape...... is attached onto two drums, followed by a rotation of both drums in opposite direction. The numerical modeling is based on integral constitutive equations of the K-BKZ type. Generally, to ensure a proper uni-axial extensional deformation in dual wind-up drum rheometers the simulations show that a very small...

  2. The early years of string theory: The dual resonance model

    International Nuclear Information System (INIS)

    Ramond, P.

    1987-10-01

    This paper reviews the past quantum mechanical history of the dual resonance model which is an early string theory. The content of this paper is listed as follows: historical review, the Veneziano amplitude, the operator formalism, the ghost story, and the string story

  3. Thermodynamic modelling and optimization of a dual pressure ...

    Indian Academy of Sciences (India)

    The exergetic losses in CC system are compared with each other. The present DPRH HRSG model has been compared and validated with the plant and published data. Keywords. Combined cycle; dual pressure; deaerator; exergy analysis; heat recovery steam generator. 1. Introduction. Combined cycle (CC) power plants ...

  4. Scale-invariant inclusive spectra in a dual model

    International Nuclear Information System (INIS)

    Chikovani, Z.E.; Jenkovsky, L.L.; Martynov, E.S.

    1979-01-01

    One-particle inclusive distributions at large transverse momentum phisub(tr) are shown to scale, Edσ/d 3 phi approximately phisub(tr)sup(-N)(1-Xsub(tr))sup(1+N/2)lnphisub(tr), in a dual model with Mandelstam analyticity if the Regge trajectories are logarithmic asymptotically

  5. Latent Feature Models for Uncovering Human Mobility Patterns from Anonymized User Location Traces with Metadata

    KAUST Repository

    Alharbi, Basma Mohammed

    2017-04-10

    In the mobile era, data capturing individuals’ locations have become unprecedentedly available. Data from Location-Based Social Networks is one example of large-scale user-location data. Such data provide a valuable source for understanding patterns governing human mobility, and thus enable a wide range of research. However, mining and utilizing raw user-location data is a challenging task. This is mainly due to the sparsity of data (at the user level), the imbalance of data with power-law users and locations check-ins degree (at the global level), and more importantly the lack of a uniform low-dimensional feature space describing users. Three latent feature models are proposed in this dissertation. Each proposed model takes as an input a collection of user-location check-ins, and outputs a new representation space for users and locations respectively. To avoid invading users privacy, the proposed models are designed to learn from anonymized location data where only IDs - not geophysical positioning or category - of locations are utilized. To enrich the inferred mobility patterns, the proposed models incorporate metadata, often associated with user-location data, into the inference process. In this dissertation, two types of metadata are utilized to enrich the inferred patterns, timestamps and social ties. Time adds context to the inferred patterns, while social ties amplifies incomplete user-location check-ins. The first proposed model incorporates timestamps by learning from collections of users’ locations sharing the same discretized time. The second proposed model also incorporates time into the learning model, yet takes a further step by considering time at different scales (hour of a day, day of a week, month, and so on). This change in modeling time allows for capturing meaningful patterns over different times scales. The last proposed model incorporates social ties into the learning process to compensate for inactive users who contribute a large volume

  6. Uncovering Implicit Assumptions: a Large-Scale Study on Students' Mental Models of Diffusion

    Science.gov (United States)

    Stains, Marilyne; Sevian, Hannah

    2015-12-01

    Students' mental models of diffusion in a gas phase solution were studied through the use of the Structure and Motion of Matter (SAMM) survey. This survey permits identification of categories of ways students think about the structure of the gaseous solute and solvent, the origin of motion of gas particles, and trajectories of solute particles in the gaseous medium. A large sample of data ( N = 423) from students across grade 8 (age 13) through upper-level undergraduate was subjected to a cluster analysis to determine the main mental models present. The cluster analysis resulted in a reduced data set ( N = 308), and then, mental models were ascertained from robust clusters. The mental models that emerged from analysis were triangulated through interview data and characterised according to underlying implicit assumptions that guide and constrain thinking about diffusion of a solute in a gaseous medium. Impacts of students' level of preparation in science and relationships of mental models to science disciplines studied by students were examined. Implications are discussed for the value of this approach to identify typical mental models and the sets of implicit assumptions that constrain them.

  7. Uncovering the influence of social skills and psychosociological factors on pain sensitivity using structural equation modeling.

    Science.gov (United States)

    Tanaka, Yoichi; Nishi, Yuki; Nishi, Yuki; Osumi, Michihiro; Morioka, Shu

    2017-01-01

    Pain is a subjective emotional experience that is influenced by psychosociological factors such as social skills, which are defined as problem-solving abilities in social interactions. This study aimed to reveal the relationships among pain, social skills, and other psychosociological factors by using structural equation modeling. A total of 101 healthy volunteers (41 men and 60 women; mean age: 36.6±12.7 years) participated in this study. To evoke participants' sense of inner pain, we showed them images of painful scenes on a PC screen and asked them to evaluate the pain intensity by using the visual analog scale (VAS). We examined the correlation between social skills and VAS, constructed a hypothetical model based on results from previous studies and the current correlational analysis results, and verified the model's fit using structural equation modeling. We found significant positive correlations between VAS and total social skills values, as well as between VAS and the "start of relationships" subscales. Structural equation modeling revealed that the values for "start of relationships" had a direct effect on VAS values (path coefficient =0.32, p social support. The results indicated that extroverted people are more sensitive to inner pain and tend to get more social support and maintain a better psychological condition.

  8. A dual-trace model for visual sensory memory.

    Science.gov (United States)

    Cappiello, Marcus; Zhang, Weiwei

    2016-11-01

    Visual sensory memory refers to a transient memory lingering briefly after the stimulus offset. Although previous literature suggests that visual sensory memory is supported by a fine-grained trace for continuous representation and a coarse-grained trace of categorical information, simultaneous separation and assessment of these traces can be difficult without a quantitative model. The present study used a continuous estimation procedure to test a novel mathematical model of the dual-trace hypothesis of visual sensory memory according to which visual sensory memory could be modeled as a mixture of 2 von Mises (2VM) distributions differing in standard deviation. When visual sensory memory and working memory (WM) for colors were distinguished using different experimental manipulations in the first 3 experiments, the 2VM model outperformed Zhang and Luck (2008) standard mixture model (SM) representing a mixture of a single memory trace and random guesses, even though SM outperformed 2VM for WM. Experiment 4 generalized 2VM's advantages of fitting visual sensory memory data over SM from color to orientation. Furthermore, a single trace model and 4 other alternative models were ruled out, suggesting the necessity and sufficiency of dual traces for visual sensory memory. Together these results support the dual-trace model of visual sensory memory and provide a preliminary inquiry into the nature of information loss from visual sensory memory to WM. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  9. Modeling Framework for Uncovering System Behaviors in Biofuels Supply Chain Network

    NARCIS (Netherlands)

    Agusdinata, D.B.; Lee, S.; Zhao, F.; DeLaurentis, D.; Thissen, W.A.H.

    2012-01-01

    A full realization of alternative energy such as biofuels depends on the existence of a viable supply chain (SC) network. This work seeks to understand the dynamics of biofuels SC network by developing an approach to model the dynamics and characterize system behavior. A multi-actor approach is

  10. Predicting sugar consumption: Application of an integrated dual-process, dual-phase model.

    Science.gov (United States)

    Hagger, Martin S; Trost, Nadine; Keech, Jacob J; Chan, Derwin K C; Hamilton, Kyra

    2017-09-01

    Excess consumption of added dietary sugars is related to multiple metabolic problems and adverse health conditions. Identifying the modifiable social cognitive and motivational constructs that predict sugar consumption is important to inform behavioral interventions aimed at reducing sugar intake. We tested the efficacy of an integrated dual-process, dual-phase model derived from multiple theories to predict sugar consumption. Using a prospective design, university students (N = 90) completed initial measures of the reflective (autonomous and controlled motivation, intentions, attitudes, subjective norm, perceived behavioral control), impulsive (implicit attitudes), volitional (action and coping planning), and behavioral (past sugar consumption) components of the proposed model. Self-reported sugar consumption was measured two weeks later. A structural equation model revealed that intentions, implicit attitudes, and, indirectly, autonomous motivation to reduce sugar consumption had small, significant effects on sugar consumption. Attitudes, subjective norm, and, indirectly, autonomous motivation to reduce sugar consumption predicted intentions. There were no effects of the planning constructs. Model effects were independent of the effects of past sugar consumption. The model identified the relative contribution of reflective and impulsive components in predicting sugar consumption. Given the prominent role of the impulsive component, interventions that assist individuals in managing cues-to-action and behavioral monitoring are likely to be effective in regulating sugar consumption. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Induced Pluripotent Stem Cell Models of Progranulin-Deficient Frontotemporal Dementia Uncover Specific Reversible Neuronal Defects

    Directory of Open Access Journals (Sweden)

    Sandra Almeida

    2012-10-01

    Full Text Available The pathogenic mechanisms of frontotemporal dementia (FTD remain poorly understood. Here we generated multiple induced pluripotent stem cell lines from a control subject, a patient with sporadic FTD, and an FTD patient with a novel heterozygous GRN mutation (progranulin [PGRN] S116X. In neurons and microglia differentiated from PGRN S116X induced pluripotent stem cells, the levels of intracellular and secreted PGRN were reduced, establishing patient-specific cellular models of PGRN haploinsufficiency. Through a systematic screen of inducers of cellular stress, we found that PGRN S116X neurons, but not sporadic FTD neurons, exhibited increased sensitivity to staurosporine and other kinase inhibitors. Moreover, the serine/threonine kinase S6K2, a component of the phosphatidylinositol 3-kinase and mitogen-activated protein kinase pathways, was specifically downregulated in PGRN S116X neurons. Both increased sensitivity to kinase inhibitors and reduced S6K2 were rescued by PGRN expression. Our findings identify cell-autonomous, reversible defects in patient neurons with PGRN deficiency, and provide a compelling model for studying PGRN-dependent pathogenic mechanisms and testing potential therapies.

  12. Finiteness of PST self-dual models

    International Nuclear Information System (INIS)

    Del Cima, Oswaldo M.; Piguet, Olivier; Sarandy, Marcelo S.

    2000-12-01

    The Pasti-Sorokin-Tonin model for describing chiral forms is considered at the quantum level. We study the ultraviolet and infrared behaviour of the model in two, four and six dimensions in the framework of algebraic renormalization. The absence of anomalies, as well as the finiteness, up to non-physical renormalizations, are shown in all dimensions analyzed. (author)

  13. Stochastic Model for Phonemes Uncovers an Author-Dependency of Their Usage.

    Directory of Open Access Journals (Sweden)

    Weibing Deng

    Full Text Available We study rank-frequency relations for phonemes, the minimal units that still relate to linguistic meaning. We show that these relations can be described by the Dirichlet distribution, a direct analogue of the ideal-gas model in statistical mechanics. This description allows us to demonstrate that the rank-frequency relations for phonemes of a text do depend on its author. The author-dependency effect is not caused by the author's vocabulary (common words used in different texts, and is confirmed by several alternative means. This suggests that it can be directly related to phonemes. These features contrast to rank-frequency relations for words, which are both author and text independent and are governed by the Zipf's law.

  14. Stochastic Model for Phonemes Uncovers an Author-Dependency of Their Usage.

    Science.gov (United States)

    Deng, Weibing; Allahverdyan, Armen E

    2016-01-01

    We study rank-frequency relations for phonemes, the minimal units that still relate to linguistic meaning. We show that these relations can be described by the Dirichlet distribution, a direct analogue of the ideal-gas model in statistical mechanics. This description allows us to demonstrate that the rank-frequency relations for phonemes of a text do depend on its author. The author-dependency effect is not caused by the author's vocabulary (common words used in different texts), and is confirmed by several alternative means. This suggests that it can be directly related to phonemes. These features contrast to rank-frequency relations for words, which are both author and text independent and are governed by the Zipf's law.

  15. Uncovering wind turbine properties through two-dimensional stochastic modeling of wind dynamics.

    Science.gov (United States)

    Raischel, Frank; Scholz, Teresa; Lopes, Vitor V; Lind, Pedro G

    2013-10-01

    Using a method for stochastic data analysis borrowed from statistical physics, we analyze synthetic data from a Markov chain model that reproduces measurements of wind speed and power production in a wind park in Portugal. We show that our analysis retrieves indeed the power performance curve, which yields the relationship between wind speed and power production, and we discuss how this procedure can be extended for extracting unknown functional relationships between pairs of physical variables in general. We also show how specific features, such as the rated speed of the wind turbine or the descriptive wind speed statistics, can be related to the equations describing the evolution of power production and wind speed at single wind turbines.

  16. Integrative modeling of small artery structure and function uncovers critical parameters for diameter regulation.

    Directory of Open Access Journals (Sweden)

    Ed VanBavel

    Full Text Available Organ perfusion is regulated by vasoactivity and structural adaptation of small arteries and arterioles. These resistance vessels are sensitive to pressure, flow and a range of vasoactive stimuli. Several strongly interacting control loops exist. As an example, the myogenic response to a change of pressure influences the endothelial shear stress, thereby altering the contribution of shear-dependent dilation to the vascular tone. In addition, acute responses change the stimulus for structural adaptation and vice versa. Such control loops are able to maintain resistance vessels in a functional and stable state, characterized by regulated wall stress, shear stress, matched active and passive biomechanics and presence of vascular reserve. In this modeling study, four adaptation processes are identified that together with biomechanical properties effectuate such integrated regulation: control of tone, smooth muscle cell length adaptation, eutrophic matrix rearrangement and trophic responses. Their combined action maintains arteries in their optimal state, ready to cope with new challenges, allowing continuous long-term vasoregulation. The exclusion of any of these processes results in a poorly regulated state and in some cases instability of vascular structure.

  17. Uncovering patterns of spring migration in the monarch butterfly using stable isotopes and demographic models

    Science.gov (United States)

    Norris, R.; Miller, N.; Wassenaar, L.; Hobson, K.

    2010-12-01

    Each spring, millions of monarch butterflies (Danaus plexippus) migrate up to 3000 km from central Mexico to re-colonize eastern North America. However, despite centuries of research, the patterns of re-colonization are not well understood. We combined stable-hydrogen (δD) and -carbon (δ13C) isotope measurements with demographic models to test (1) whether individuals sampled in the northern part of the breeding range in the Great Lakes originate directly from Mexico or are second generation individuals born in the southern US and (2) to estimate whether populations on the eastern seaboard migrate longitudinally over the Appalachians or originate directly from the Gulf Coast. In the Great Lakes, we found that the majority of individuals were second-generation monarchs born in the Gulf Coast and Central regions of the US. However, 25% individuals originated directly from Mexico and we estimated that these individuals produced the majority of offspring born in the Great Lakes region during June. On the eastern seaboard, we found the majority of monarchs (88%) originated in the mid-west and Great Lakes regions, providing the first direct evidence that second generation monarchs born in June complete a (trans-) longitudinal migration across the Appalachian mountains. The remaining individuals (12%) originated from parents that migrated directly from the Gulf coast during early spring. Our results demonstrate how stable isotopes, when combined with ecological data, can provide insights into patterns of connectivity in migratory insects that have been impossible to test using conventional techniques. The migration patterns presented here have important implications for predicting future changes in population size and for developing effective conservation plans for this species.

  18. A dual porosity model of nutrient uptake by root hairs

    KAUST Repository

    Zygalakis, K. C.

    2011-08-09

    Summary: • The importance of root hairs in the uptake of sparingly soluble nutrients is understood qualitatively, but not quantitatively, and this limits efforts to breed plants tolerant of nutrient-deficient soils. • Here, we develop a mathematical model of nutrient uptake by root hairs allowing for hair geometry and the details of nutrient transport through soil, including diffusion within and between soil particles. We give illustrative results for phosphate uptake. • Compared with conventional \\'single porosity\\' models, this \\'dual porosity\\' model predicts greater root uptake because more nutrient is available by slow release from within soil particles. Also the effect of soil moisture is less important with the dual porosity model because the effective volume available for diffusion in the soil is larger, and the predicted effects of hair length and density are different. • Consistent with experimental observations, with the dual porosity model, increases in hair length give greater increases in uptake than increases in hair density per unit main root length. The effect of hair density is less in dry soil because the minimum concentration in solution for net influx is reached more rapidly. The effect of hair length is much less sensitive to soil moisture. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

  19. Model tracking dual stochastic controller design under irregular internal noises

    International Nuclear Information System (INIS)

    Lee, Jong Bok; Heo, Hoon; Cho, Yun Hyun; Ji, Tae Young

    2006-01-01

    Although many methods about the control of irregular external noise have been introduced and implemented, it is still necessary to design a controller that will be more effective and efficient methods to exclude for various noises. Accumulation of errors due to model tracking, internal noises (thermal noise, shot noise and l/f noise) that come from elements such as resistor, diode and transistor etc. in the circuit system and numerical errors due to digital process often destabilize the system and reduce the system performance. New stochastic controller is adopted to remove those noises using conventional controller simultaneously. Design method of a model tracking dual controller is proposed to improve the stability of system while removing external and internal noises. In the study, design process of the model tracking dual stochastic controller is introduced that improves system performance and guarantees robustness under irregular internal noises which can be created internally. The model tracking dual stochastic controller utilizing F-P-K stochastic control technique developed earlier is implemented to reveal its performance via simulation

  20. Functional mathematical model of dual pathway AV nodal conduction.

    Science.gov (United States)

    Climent, A M; Guillem, M S; Zhang, Y; Millet, J; Mazgalev, T N

    2011-04-01

    Dual atrioventricular (AV) nodal pathway physiology is described as two different wave fronts that propagate from the atria to the His bundle: one with a longer effective refractory period [fast pathway (FP)] and a second with a shorter effective refractory period [slow pathway (SP)]. By using His electrogram alternance, we have developed a mathematical model of AV conduction that incorporates dual AV nodal pathway physiology. Experiments were performed on five rabbit atrial-AV nodal preparations to develop and test the presented model. His electrogram alternances from the inferior margin of the His bundle were used to identify fast and slow wave front propagations. The ability to predict AV conduction time and the interaction between FP and SP wave fronts have been analyzed during regular and irregular atrial rhythms (e.g., atrial fibrillation). In addition, the role of dual AV nodal pathway wave fronts in the generation of Wenckebach periodicities has been illustrated. Finally, AV node ablative modifications have been evaluated. The model accurately reproduced interactions between FP and SP during regular and irregular atrial pacing protocols. In all experiments, specificity and sensitivity higher than 85% were obtained in the prediction of the pathway responsible for conduction. It has been shown that, during atrial fibrillation, the SP ablation significantly increased the mean HH interval (204 ± 39 vs. 274 ± 50 ms, P AV node mechanisms and should be considered as a step forward in the studies of AV nodal conduction.

  1. QCD Dual

    DEFF Research Database (Denmark)

    Sannino, Francesco

    2009-01-01

    We uncover a novel solution of the 't Hooft anomaly matching conditions for QCD. Interestingly in the perturbative regime the new gauge theory, if interpreted as a possible QCD dual, predicts the critical number of flavors above which QCD in the nonperturbative regime, develops an infrared stable...

  2. Numerical Modeling of a Precise Dual Axis Positioning System

    Directory of Open Access Journals (Sweden)

    Giedrius Augustinavičius

    2012-01-01

    Full Text Available This paper presents a model of a precise dual axis flexure-based positioning system for micro-positioning uses. The positioning system is featured with monolithic architecture, flexure-based joints and ultra fine adjustment screws. Its workspace has been evaluated via analytical approaches. Reduction mechanism is optimally designed. The mathematical model of the positioning system has been derived and verified by resorting to finite element analysis (FEA. The established analytical and (FEA models are helpful for reliable architecture optimization and performance improvement in the positioning system.Article in Lithuanian

  3. Dual Superconductivity in Abelian Higgs Model of QCD

    Science.gov (United States)

    Rajput, B. S.

    2017-04-01

    The study of generalized field associated with Abelian dyons has been undertaken and it has been demonstrated that topologically, a non-Abelian gauge theory is equivalent to a set of Abelian gauge theories supplemented by dyons which undergo condensation leading to confinement and consequently to superconducting model of QCD vacuum, where the Higgs field plays the role of a regulator only. Constructing the effective action for dyonic field in Abelian projection of QCD, it has been demonstrated that any charge (electrical or magnetic) of dyon screens its own direct potential to which it minimally couples and anti-screens the dual potential leading to dual superconductivity in accordance with generalized Meissner effect. In this Abelian projection of QCD an Abelian Higgs model (AHM) has been successfully constructed and it has been shown to incorporate dual superconductivity and confinement as the consequence of dyonic condensation. It has been demonstrated that in AHM t' Hooft loop creates the string (AHM-string) around which the monopole current under London limit leads to vanishing coherence length in the chromo-magnetic superconductor. It has also been shown that in London limit the squared density of monopole current around AHM-string has a maximum at the distance of the order of penetration length.

  4. Interacting-string picture of dual-resonance models

    International Nuclear Information System (INIS)

    Mandelstam, S.

    1985-01-01

    Dual-resonance models are an alyzed by means of operators which act within the physical Hilbert space of positive-metric states. The basis of the method is to extend the relativistic-string picture of a previous study to interacting particles. Functional methods are used, but their relation to the operator is evident, and factorization is maintained. An expression is given for the N-point amplitude in terms of physical-particle operators. For the three-point function the Neumann functions which occur in this expression are evaluated, so that we have a formula for the on- and off-energy-shell vertex. The authors assume that the string has no longitudinal degrees of freedom, and their results are Lorentz invariant and dual only if d=26

  5. 3D modeling of dual-gate FinFET.

    Science.gov (United States)

    Mil'shtein, Samson; Devarakonda, Lalitha; Zanchi, Brian; Palma, John

    2012-11-13

    The tendency to have better control of the flow of electrons in a channel of field-effect transistors (FETs) did lead to the design of two gates in junction field-effect transistors, field plates in a variety of metal semiconductor field-effect transistors and high electron mobility transistors, and finally a gate wrapping around three sides of a narrow fin-shaped channel in a FinFET. With the enhanced control, performance trends of all FETs are still challenged by carrier mobility dependence on the strengths of the electrical field along the channel. However, in cases when the ratio of FinFET volume to its surface dramatically decreases, one should carefully consider the surface boundary conditions of the device. Moreover, the inherent non-planar nature of a FinFET demands 3D modeling for accurate analysis of the device performance. Using the Silvaco modeling tool with quantization effects, we modeled a physical FinFET described in the work of Hisamoto et al. (IEEE Tran. Elec. Devices 47:12, 2000) in 3D. We compared it with a 2D model of the same device. We demonstrated that 3D modeling produces more accurate results. As 3D modeling results came close to experimental measurements, we made the next step of the study by designing a dual-gate FinFET biased at Vg1 >Vg2. It is shown that the dual-gate FinFET carries higher transconductance than the single-gate device.

  6. Dual processing model of medical decision-making.

    Science.gov (United States)

    Djulbegovic, Benjamin; Hozo, Iztok; Beckstead, Jason; Tsalatsanis, Athanasios; Pauker, Stephen G

    2012-09-03

    Dual processing theory of human cognition postulates that reasoning and decision-making can be described as a function of both an intuitive, experiential, affective system (system I) and/or an analytical, deliberative (system II) processing system. To date no formal descriptive model of medical decision-making based on dual processing theory has been developed. Here we postulate such a model and apply it to a common clinical situation: whether treatment should be administered to the patient who may or may not have a disease. We developed a mathematical model in which we linked a recently proposed descriptive psychological model of cognition with the threshold model of medical decision-making and show how this approach can be used to better understand decision-making at the bedside and explain the widespread variation in treatments observed in clinical practice. We show that physician's beliefs about whether to treat at higher (lower) probability levels compared to the prescriptive therapeutic thresholds obtained via system II processing is moderated by system I and the ratio of benefit and harms as evaluated by both system I and II. Under some conditions, the system I decision maker's threshold may dramatically drop below the expected utility threshold derived by system II. This can explain the overtreatment often seen in the contemporary practice. The opposite can also occur as in the situations where empirical evidence is considered unreliable, or when cognitive processes of decision-makers are biased through recent experience: the threshold will increase relative to the normative threshold value derived via system II using expected utility threshold. This inclination for the higher diagnostic certainty may, in turn, explain undertreatment that is also documented in the current medical practice. We have developed the first dual processing model of medical decision-making that has potential to enrich the current medical decision-making field, which is still to the

  7. Dual processing model of medical decision-making

    Science.gov (United States)

    2012-01-01

    Background Dual processing theory of human cognition postulates that reasoning and decision-making can be described as a function of both an intuitive, experiential, affective system (system I) and/or an analytical, deliberative (system II) processing system. To date no formal descriptive model of medical decision-making based on dual processing theory has been developed. Here we postulate such a model and apply it to a common clinical situation: whether treatment should be administered to the patient who may or may not have a disease. Methods We developed a mathematical model in which we linked a recently proposed descriptive psychological model of cognition with the threshold model of medical decision-making and show how this approach can be used to better understand decision-making at the bedside and explain the widespread variation in treatments observed in clinical practice. Results We show that physician’s beliefs about whether to treat at higher (lower) probability levels compared to the prescriptive therapeutic thresholds obtained via system II processing is moderated by system I and the ratio of benefit and harms as evaluated by both system I and II. Under some conditions, the system I decision maker’s threshold may dramatically drop below the expected utility threshold derived by system II. This can explain the overtreatment often seen in the contemporary practice. The opposite can also occur as in the situations where empirical evidence is considered unreliable, or when cognitive processes of decision-makers are biased through recent experience: the threshold will increase relative to the normative threshold value derived via system II using expected utility threshold. This inclination for the higher diagnostic certainty may, in turn, explain undertreatment that is also documented in the current medical practice. Conclusions We have developed the first dual processing model of medical decision-making that has potential to enrich the current medical

  8. [Dual neural circuit model of reading and writing].

    Science.gov (United States)

    Iwata, Makoto

    2011-08-01

    In the hypothetical neural circuit model of reading and writing that was initially proposed by Dejerine and subsequently confirmed by Geschwind, the left angular gyrus was considered as a unique center for processing letters. Japanese investigators, however, have repeatedly pointed out that this angular gyrus model cannot fully explain the disturbances observed in reading and writing Kanji letters in Japanese patients with various types of alexia with or without agraphia. In 1982, I proposed a dual neural circuit model of reading and writing Japanese on the basis of neuropsychological studies on the various types of alexia with or without agraphia without aphasia. This dual neural circuit model proposes that apart from the left angular gyrus which was thought to be a node for phonological processing of letters, the left posterior inferior temporal area, also acts as a node for semantic processing of letters. Further investigations using O15-PET activation on normal subjects revealed that the left middle occipital gyrus (area 19 of Brodmann) and the posterior portion of the left inferior temporal gyrus (area 37 of Brodmann) are the cortical areas responsible for reading Japanese letters; the former serving for phonological reading and the latter for semantic reading. This duality of the neural circuit in processing letters was later applied to explain disturbances in reading English, and was finally accepted as a valid model for other alphabetic letter systems too.

  9. International Family Migration and the Dual-Earner Model

    DEFF Research Database (Denmark)

    Munk, Martin D.; Nikolka, Till; Poutvaara, Panu

    2018-01-01

    Gender differences in labor force participation are exceptionally small in Nordic countries. We investigate how couples emigrating from Denmark self-select and sort into different destinations and whether couples pursue the dual-earner model, in which both partners work, when abroad. Female labor...... force participation is slightly lower among couples that later emigrate, and drops considerably after migration outside the Nordic countries. Pre-migration differences between couples subsequently migrating to different destinations are small. Our survey reveals that couple migration is usually driven...... by the male’s job opportunities. The results suggest that increasing international migration may reduce women’s career investments....

  10. Nonscaling parametrization of hadronic spectra and dual parton model

    International Nuclear Information System (INIS)

    Gaponenko, O.N.

    2001-01-01

    Using the popular Wdowczyk-Wolfendale parametrization (WW-parametrization) as an example one studies restrictions imposed by a dual parton model for different nonscaling parametrizations of the pulsed hadron spectra in soft hadron-hadron and hadron-nuclear interactions. One derived a new parametrization free from basic drawback of the WW-formulae. In the central range the determined parametrization show agreement with the Wdowczyk-Wolfendale formula, but in contrast to the last-named one it does not result in contradiction with the experiment due to fast reduction of inelastic factor reduction with energy increase [ru

  11. Improved dual sided doped memristor: modelling and applications

    Directory of Open Access Journals (Sweden)

    Anup Shrivastava

    2014-05-01

    Full Text Available Memristor as a novel and emerging electronic device having vast range of applications suffer from poor frequency response and saturation length. In this paper, the authors present a novel and an innovative device structure for the memristor with two active layers and its non-linear ionic drift model for an improved frequency response and saturation length. The authors investigated and compared the I–V characteristics for the proposed model with the conventional memristors and found better results in each case (different window functions for the proposed dual sided doped memristor. For circuit level simulation, they developed a SPICE model of the proposed memristor and designed some logic gates based on hybrid complementary metal oxide semiconductor memristive logic (memristor ratioed logic. The proposed memristor yields improved results in terms of noise margin, delay time and dynamic hazards than that of the conventional memristors (single active layer memristors.

  12. 3D modeling of dual-gate FinFET

    Science.gov (United States)

    Mil'shtein, Samson; Devarakonda, Lalitha; Zanchi, Brian; Palma, John

    2012-11-01

    The tendency to have better control of the flow of electrons in a channel of field-effect transistors (FETs) did lead to the design of two gates in junction field-effect transistors, field plates in a variety of metal semiconductor field-effect transistors and high electron mobility transistors, and finally a gate wrapping around three sides of a narrow fin-shaped channel in a FinFET. With the enhanced control, performance trends of all FETs are still challenged by carrier mobility dependence on the strengths of the electrical field along the channel. However, in cases when the ratio of FinFET volume to its surface dramatically decreases, one should carefully consider the surface boundary conditions of the device. Moreover, the inherent non-planar nature of a FinFET demands 3D modeling for accurate analysis of the device performance. Using the Silvaco modeling tool with quantization effects, we modeled a physical FinFET described in the work of Hisamoto et al. (IEEE Tran. Elec. Devices 47:12, 2000) in 3D. We compared it with a 2D model of the same device. We demonstrated that 3D modeling produces more accurate results. As 3D modeling results came close to experimental measurements, we made the next step of the study by designing a dual-gate FinFET biased at V g1 > V g2. It is shown that the dual-gate FinFET carries higher transconductance than the single-gate device.

  13. Developmental Dyslexia and the Dual Route Model of Reading: Simulating Individual Differences and Subtypes

    Science.gov (United States)

    Ziegler, Johannes C.; Castel, Caroline; Pech-Georgel, Catherine; George, Florence; Alario, F-Xavier; Perry, Conrad

    2008-01-01

    Developmental dyslexia was investigated within a well-understood and fully specified computational model of reading aloud: the dual route cascaded model (DRC [Coltheart, M., Rastle, K., Perry, C., Langdon, R., & Ziegler, J.C. (2001). DRC: A dual route cascaded model of visual word recognition and reading aloud. Psychological Review, 108,…

  14. Dual deep modeling: multi-level modeling with dual potencies and its formalization in F-Logic.

    Science.gov (United States)

    Neumayr, Bernd; Schuetz, Christoph G; Jeusfeld, Manfred A; Schrefl, Michael

    2018-01-01

    An enterprise database contains a global, integrated, and consistent representation of a company's data. Multi-level modeling facilitates the definition and maintenance of such an integrated conceptual data model in a dynamic environment of changing data requirements of diverse applications. Multi-level models transcend the traditional separation of class and object with clabjects as the central modeling primitive, which allows for a more flexible and natural representation of many real-world use cases. In deep instantiation, the number of instantiation levels of a clabject or property is indicated by a single potency. Dual deep modeling (DDM) differentiates between source potency and target potency of a property or association and supports the flexible instantiation and refinement of the property by statements connecting clabjects at different modeling levels. DDM comes with multiple generalization of clabjects, subsetting/specialization of properties, and multi-level cardinality constraints. Examples are presented using a UML-style notation for DDM together with UML class and object diagrams for the representation of two-level user views derived from the multi-level model. Syntax and semantics of DDM are formalized and implemented in F-Logic, supporting the modeler with integrity checks and rich query facilities.

  15. Extended charge banking model of dual path shocks for implantable cardioverter defibrillators.

    Science.gov (United States)

    Dosdall, Derek J; Sweeney, James D

    2008-08-01

    Single path defibrillation shock methods have been improved through the use of the Charge Banking Model of defibrillation, which predicts the response of the heart to shocks as a simple resistor-capacitor (RC) circuit. While dual path defibrillation configurations have significantly reduced defibrillation thresholds, improvements to dual path defibrillation techniques have been limited to experimental observations without a practical model to aid in improving dual path defibrillation techniques. The Charge Banking Model has been extended into a new Extended Charge Banking Model of defibrillation that represents small sections of the heart as separate RC circuits, uses a weighting factor based on published defibrillation shock field gradient measures, and implements a critical mass criteria to predict the relative efficacy of single and dual path defibrillation shocks. The new model reproduced the results from several published experimental protocols that demonstrated the relative efficacy of dual path defibrillation shocks. The model predicts that time between phases or pulses of dual path defibrillation shock configurations should be minimized to maximize shock efficacy. Through this approach the Extended Charge Banking Model predictions may be used to improve dual path and multi-pulse defibrillation techniques, which have been shown experimentally to lower defibrillation thresholds substantially. The new model may be a useful tool to help in further improving dual path and multiple pulse defibrillation techniques by predicting optimal pulse durations and shock timing parameters.

  16. Dyon Condensation and Dual Superconductivity in Abelian Higgs Model of QCD

    Directory of Open Access Journals (Sweden)

    B. S. Rajput

    2010-01-01

    Full Text Available Constructing the effective action for dyonic field in Abelian projection of QCD, it has been demonstrated that any charge (electrical or magnetic of dyon screens its own direct potential to which it minimally couples and antiscreens the dual potential leading to dual superconductivity in accordance with generalized Meissner effect. Taking the Abelian projection of QCD, an Abelian Higgs model, incorporating dual superconductivity and confinement, has been constructed and its representation has been obtained in terms of average of Wilson loop.

  17. Development of smart controller model for dual fuel generator systems

    African Journals Online (AJOL)

    Application of dual fuel powered electric generators such as one of diesel and biogas has gained popularity locally both as emergency power supply units and in distributed power systems. Dual fuel generators use two fuel types simultaneously in their operations. This is however faced with challenges in control and fuel ...

  18. Dual permeability modeling of flow in a fractured geothermal reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Miller, J.D.; Allman, D.W.

    1986-01-01

    A three dimensional fracture system synthesis and flow simulation has been developed to correlate drawdown characteristics measured in a geothermal well and to provide the basis for an analysis of tracer tests. A new dual permeability approach was developed which incorporates simulations at two levels to better represent a discrete fracture system within computer limitations. The first incorporates a discrete simulation of the largest fractures in the system plus distributed or representative element stimulation of the smaller fractures. The second determines the representative element properties by discrete simulation of the smaller fractures. The fracture system was synthesized from acoustic televiewer data on the orientation and separation of three distinct fracture sets, together with additional data from the literature. Lognormal and exponential distributions of fracture spacing and radius were studied with the exponential distribution providing more reasonable results. Hydraulic apertures were estimated as a function of distance from the model boundary to a constant head boundary. Mean values of 6.7, 101 and 46 ..mu..m were chosen as the most representative values for the three fracture sets. Recommendations are given for the additional fracture characterization needed to reduce the uncertainties in the model. 20 refs., 6 figs.

  19. Prediction models for performance and emissions of a dual fuel CI ...

    Indian Academy of Sciences (India)

    Dual fuel engines are being used these days to overcome shortage of fossil fuels and fulfill stringent exhaust gas emission regulations. They have several advantages over conventional diesel engines. In this context, this paper makes use of experimental results obtained from a dual fuel engine for developing models to ...

  20. A Test of Two Alternative Cognitive Processing Models: Learning Styles and Dual Coding

    Science.gov (United States)

    Cuevas, Joshua; Dawson, Bryan L.

    2018-01-01

    This study tested two cognitive models, learning styles and dual coding, which make contradictory predictions about how learners process and retain visual and auditory information. Learning styles-based instructional practices are common in educational environments despite a questionable research base, while the use of dual coding is less…

  1. A Sound Processor for Cochlear Implant Using a Simple Dual Path Nonlinear Model of Basilar Membrane

    OpenAIRE

    Kim, Kyung Hwan; Choi, Sung Jin; Kim, Jin Ho

    2013-01-01

    We propose a new active nonlinear model of the frequency response of the basilar membrane in biological cochlea called the simple dual path nonlinear (SDPN) model and a novel sound processing strategy for cochlear implants (CIs) based upon this model. The SDPN model was developed to utilize the advantages of the level-dependent frequency response characteristics of the basilar membrane for robust formant representation under noisy conditions. In comparison to the dual resonance nonlinear mode...

  2. Control of gravitropic orientation. II. Dual receptor model for gravitropism

    Science.gov (United States)

    LaMotte, Clifford E.; Pickard, Barbara G.

    2004-01-01

    Gravitropism of vascular plants has been assumed to require a single gravity receptor mechanism. However, based on the evidence in Part I of this study, we propose that maize roots require two. The first mechanism is without a directional effect and, by itself, cannot give rise to tropism. Its role is quantitative facilitation of the second mechanism, which is directional like the gravitational force itself and provides the impetus for tropic curvature. How closely coupled the two mechanisms may be is, as yet, unclear. The evidence for dual receptors supports a general model for roots. When readiness for gravifacilitation, or gravifacilitation itself, is constitutive, orthogravitropic curvature can go to completion. If not constitutively enabled, gravifacilitation can be weak in the absence of light and water deficit or strong in the presence of light and water deficit. In either case, it can decay and permit roots to assume reproducible non-vertical orientations (plagiogravitropic or plagiotropic orientations) without using non-vertical setpoints. In this way roots are deployed in a large volume of soil. Gravitropic behaviours in shoots are more diverse than in roots, utilising oblique and horizontal as well as vertical setpoints. As a guide to future experiments, we assess how constitutive v. non-constitutive modes of gravifacilitation might contribute to behaviours based on each kind of setpoint.

  3. Extracting atomic numbers and electron densities from a dual source dual energy CT scanner: experiments and a simulation model.

    Science.gov (United States)

    Landry, Guillaume; Reniers, Brigitte; Granton, Patrick Vincent; van Rooijen, Bart; Beaulieu, Luc; Wildberger, Joachim E; Verhaegen, Frank

    2011-09-01

    Dual energy CT (DECT) imaging can provide both the electron density ρ(e) and effective atomic number Z(eff), thus facilitating tissue type identification. This paper investigates the accuracy of a dual source DECT scanner by means of measurements and simulations. Previous simulation work suggested improved Monte Carlo dose calculation accuracy when compared to single energy CT for low energy photon brachytherapy, but lacked validation. As such, we aim to validate our DECT simulation model in this work. A cylindrical phantom containing tissue mimicking inserts was scanned with a second generation dual source scanner (SOMATOM Definition FLASH) to obtain Z(eff) and ρ(e). A model of the scanner was designed in ImaSim, a CT simulation program, and was used to simulate the experiment. Accuracy of measured Z(eff) (labelled Z) was found to vary from -10% to 10% from low to high Z tissue substitutes while the accuracy on ρ(e) from DECT was about 2.5%. Our simulation reproduced the experiments within ±5% for both Z and ρ(e). A clinical DECT scanner was able to extract Z and ρ(e) of tissue substitutes. Our simulation tool replicates the experiments within a reasonable accuracy. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  4. Slow Steps towards Dual Earner/Dual Carer Family Model: Why Do Fathers Not Take Parental Leave

    Directory of Open Access Journals (Sweden)

    Marre Karu

    2011-06-01

    Full Text Available The article looks at the transition of Estonian society towards dual earner/dual carer family model and focuses on fathers’ decision regarding taking their parental leave. Based on theory of planned behaviour by Ajzen, data from 20 qualitative interviews with fathers of small children are analysed to explore the beliefs fathers have when it comes to parental leave. The analysis distinguishes between two images of ‘good parenting’ that play a role in the fathers’ intention to take parental leave. First, there is an image of an outcome-oriented ‘project manager’ affected by failure anxiety, and second, there is a much more relaxed image of a ‘good parent’ as a ‘companion’ who values everyday contact and a close relationship with the child(ren.

  5. Design of a dual-hormone model predictive control for artificial pancreas with exercise model.

    Science.gov (United States)

    Resalat, Navid; El Youssef, Joseph; Reddy, Ravi; Jacobs, Peter G

    2016-08-01

    The Artificial Pancreas (AP) is a new technology for helping people with type 1 diabetes to better control their glucose levels through automated delivery of insulin and optionally glucagon in response to sensed glucose levels. In a dual hormone AP, insulin and glucagon are delivered automatically to the body based on glucose sensor measurements using a control algorithm that calculates the amount of hormones to be infused. A dual-hormone MPC may deliver insulin continuously; however, it must avoid continuous delivery of glucagon because nausea can occur from too much glucagon. In this paper, we propose a novel dual-hormone (DH) switching model predictive control and compare it with a single-hormone (SH) MPC. We extended both MPCs by integrating an exercise model and compared performance with and without the exercise model included. Results were obtained on a virtual patient population undergoing a simulated exercise event using a mathematical glucoregulatory model that includes exercise. Time spent in hypoglycemia is significantly less with the DH-MPC than the SH-MPC (p=0.0022). Additionally, including the exercise model in the DH-MPC can help prevent hypoglycemia (p <; 0.001).

  6. Dual permeability FEM models for distributed fiber optic sensors development

    Science.gov (United States)

    Aguilar-López, Juan Pablo; Bogaard, Thom

    2017-04-01

    Fiber optic cables are commonly known for being robust and reliable mediums for transferring information at the speed of light in glass. Billions of kilometers of cable have been installed around the world for internet connection and real time information sharing. Yet, fiber optic cable is not only a mean for information transfer but also a way to sense and measure physical properties of the medium in which is installed. For dike monitoring, it has been used in the past for detecting inner core and foundation temperature changes which allow to estimate water infiltration during high water events. The DOMINO research project, aims to develop a fiber optic based dike monitoring system which allows to directly sense and measure any pore pressure change inside the dike structure. For this purpose, questions like which location, how many sensors, which measuring frequency and which accuracy are required for the sensor development. All these questions may be initially answered with a finite element model which allows to estimate the effects of pore pressure change in different locations along the cross section while having a time dependent estimation of a stability factor. The sensor aims to monitor two main failure mechanisms at the same time; The piping erosion failure mechanism and the macro-stability failure mechanism. Both mechanisms are going to be modeled and assessed in detail with a finite element based dual permeability Darcy-Richards numerical solution. In that manner, it is possible to assess different sensing configurations with different loading scenarios (e.g. High water levels, rainfall events and initial soil moisture and permeability conditions). The results obtained for the different configurations are later evaluated based on an entropy based performance evaluation. The added value of this kind of modelling approach for the sensor development is that it allows to simultaneously model the piping erosion and macro-stability failure mechanisms in a time

  7. Model predictive control for a dual active bridge inverter with a floating bridge

    OpenAIRE

    Chowdhury, Shajjad; Wheeler, Patrick W.; Gerada, C.; Patel, Chintan

    2016-01-01

    This paper presents a Model Predictive Control technique applied to a dual active bridge inverter where one of the bridges is floating. The proposed floating bridge topology eliminates the need for isolation transformer in a dual inverter system and therefore reduces the size, weight and losses in the system. To achieve multilevel output voltage waveforms the floating inverter DC link capacitor is charged to the half of the main DC link voltage. A finite-set Model Predictive Control technique...

  8. Application of the dual reciprocity boundary element method for numerical modelling of solidification process

    Directory of Open Access Journals (Sweden)

    E. Majchrzak

    2008-12-01

    Full Text Available The dual reciprocity boundary element method is applied for numerical modelling of solidification process. This variant of the BEM is connected with the transformation of the domain integral to the boundary integrals. In the paper the details of the dual reciprocity boundary element method are presented and the usefulness of this approach to solidification process modelling is demonstrated. In the final part of the paper the examples of computations are shown.

  9. Modeling of dual cylinder wind-up extensional rheometers

    DEFF Research Database (Denmark)

    Yu, Kaijia; Marin, Jose; Jensen, Mette

    measurements are useful for polymer characterization. The Sentmanat extensional Rheometer[1] is an new testing platform for the study of polymers and elastomers in extensional flow. This technique employs a dual wind-up drum technique to perform an uni-axial extensional deformation during experiments...

  10. Thermodynamic modelling and optimization of a dual pressure ...

    Indian Academy of Sciences (India)

    In this work, attention was focused on a dual pressure reheat (DPRH) HRSG to maximize the heat recovery and hence performance of CC. Deaerator, an essential open feed water ... Author Affiliations. T Srinivas1. School of Mechanical and Building Sciences, Vellore Institute of Technology University, Vellore 632 014 ...

  11. Direct Evidence for a Dual Process Model of Deductive Inference

    Science.gov (United States)

    Markovits, Henry; Brunet, Marie-Laurence; Thompson, Valerie; Brisson, Janie

    2013-01-01

    In 2 experiments, we tested a strong version of a dual process theory of conditional inference (cf. Verschueren et al., 2005a, 2005b) that assumes that most reasoners have 2 strategies available, the choice of which is determined by situational variables, cognitive capacity, and metacognitive control. The statistical strategy evaluates inferences…

  12. Creating Agent-Based Energy Transition Management Models That Can Uncover Profitable Pathways to Climate Change Mitigation

    Directory of Open Access Journals (Sweden)

    Auke Hoekstra

    2017-01-01

    Full Text Available The energy domain is still dominated by equilibrium models that underestimate both the dangers and opportunities related to climate change. In reality, climate and energy systems contain tipping points, feedback loops, and exponential developments. This paper describes how to create realistic energy transition management models: quantitative models that can discover profitable pathways from fossil fuels to renewable energy. We review the literature regarding agent-based economics, disruptive innovation, and transition management and determine the following requirements. Actors must be detailed, heterogeneous, interacting, learning, and strategizing. Technology should be represented as a detailed and heterogeneous portfolio that can develop in a bottom-up manner, using endogenous feedback loops. Assumptions about discount rates and the social cost of carbon should be configurable. The model should contain interactions between the global, national, local, and individual level. A review of modelling techniques shows that equilibrium models are unsuitable and that system dynamics and discrete event simulation are too limited. The agent-based approach is found to be uniquely suited for the complex adaptive sociotechnical systems that must be modelled. But the choice for agent-based models does not mean a rejection of other approaches because they can be accommodated within the agent-based framework. We conclude with practical guidelines.

  13. Solving the sign problems of the massless lattice Schwinger model with a dual formulation

    Directory of Open Access Journals (Sweden)

    Christof Gattringer

    2015-08-01

    Full Text Available We derive an exact representation of the massless Schwinger model on the lattice in terms of dual variables which are configurations of loops, dimers and plaquette occupation numbers. When expressed with the dual variables the partition sum has only real and positive terms also when a chemical potential or a topological term are added – situations where the conventional representation has a complex action problem. The dual representation allows for Monte Carlo simulations without restrictions on the values of the chemical potential or the vacuum angle.

  14. A dual view of the 3d Heisenberg model and the abelian projection

    OpenAIRE

    Di Giacomo, A.; Martelli, D.; Paffuti, G.

    1999-01-01

    The Heisenberg model in 3d is studied from a dual point of view. It is shown that it can have vortex configurations, carrying a conserved charge(U(1) symmetry). Vortices condens in the disordered phase. A disorder parameter $\\leftangle\\mu\\rightangle$ is defined dual to the magnetization $\\leftangle\\vec n\\rightangle$, which signals condensation of vortices, i.e. spontaneous breaking of the dual U(1) symmetry. This study sheds light on the procedure known as abelian projection in non abelian ga...

  15. Connection between Einstein equations, nonlinear sigma models, and self-dual Yang-Mills theory

    International Nuclear Information System (INIS)

    Sanchez, N.; Whiting, B.

    1986-01-01

    The authors analyze the connection between nonlinear sigma models self-dual Yang-Mills theory, and general relativity (self-dual and non-self-dual, with and without killing vectors), both at the level of the equations and at the level of the different type of solutions (solitons and calorons) of these theories. They give a manifestly gauge invariant formulation of the self-dual gravitational field analogous to that given by Yang for the self-dual Yang-Mills field. This formulation connects in a direct and explicit way the self-dual Yang-Mills and the general relativity equations. They give the ''R gauge'' parametrization of the self-dual gravitational field (which corresponds to modified Yang's-type and Ernst equations) and analyze the correspondence between their different types of solutions. No assumption about the existence of symmetries in the space-time is needed. For the general case (non-self-dual), they show that the Einstein equations contain an O nonlinear sigma model. This connection with the sigma model holds irrespective of the presence of symmetries in the space-time. They found a new class of solutions of Einstein equations depending on holomorphic and antiholomorphic functions and we relate some subclasses of these solutions to solutions of simpler nonlinear field equations that are well known in other branches of physics, like sigma models, SineGordon, and Liouville equations. They include gravitational plane wave solutions. They analyze the response of different accelerated quantum detector models, compare them to the case when the detectors are linterial in an ordinary Planckian gas at a given temperature, and discuss the anisotropy of the detected response for Rindler observers

  16. Modeling oscillatory dynamics in brain microcircuits as a way to help uncover neurological disease mechanisms: A proposal

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, F. K. [Toronto Western Research Institute, University Health Network, Krembil Discovery Tower, Toronto Western Hospital, 60 Leonard Street, 7th floor, 7KD411, Toronto, Ontario M5T 2S8 (Canada); Department of Medicine (Neurology), University of Toronto, 200 Elizabeth Street, Toronto, Ontario M5G 2C4 (Canada); Department of Physiology, University of Toronto Medical Sciences Building, 3rd Floor, 1 King' s College Circle, Toronto, Ontario M5S 1A8 (Canada); Ferguson, K. A. [Toronto Western Research Institute, University Health Network, Krembil Discovery Tower, Toronto Western Hospital, 60 Leonard Street, 7th floor, 7KD411, Toronto, Ontario M5T 2S8 (Canada); Department of Physiology, University of Toronto Medical Sciences Building, 3rd Floor, 1 King' s College Circle, Toronto, Ontario M5S 1A8 (Canada)

    2013-12-15

    There is an undisputed need and requirement for theoretical and computational studies in Neuroscience today. Furthermore, it is clear that oscillatory dynamical output from brain networks is representative of various behavioural states, and it is becoming clear that one could consider these outputs as measures of normal and pathological brain states. Although mathematical modeling of oscillatory dynamics in the context of neurological disease exists, it is a highly challenging endeavour because of the many levels of organization in the nervous system. This challenge is coupled with the increasing knowledge of cellular specificity and network dysfunction that is associated with disease. Recently, whole hippocampus in vitro preparations from control animals have been shown to spontaneously express oscillatory activities. In addition, when using preparations derived from animal models of disease, these activities show particular alterations. These preparations present an opportunity to address challenges involved with using models to gain insight because of easier access to simultaneous cellular and network measurements, and pharmacological modulations. We propose that by developing and using models with direct links to experiment at multiple levels, which at least include cellular and microcircuit, a cycling can be set up and used to help us determine critical mechanisms underlying neurological disease. We illustrate our proposal using our previously developed inhibitory network models in the context of these whole hippocampus preparations and show the importance of having direct links at multiple levels.

  17. Modeling oscillatory dynamics in brain microcircuits as a way to help uncover neurological disease mechanisms: A proposal

    Science.gov (United States)

    Skinner, F. K.; Ferguson, K. A.

    2013-12-01

    There is an undisputed need and requirement for theoretical and computational studies in Neuroscience today. Furthermore, it is clear that oscillatory dynamical output from brain networks is representative of various behavioural states, and it is becoming clear that one could consider these outputs as measures of normal and pathological brain states. Although mathematical modeling of oscillatory dynamics in the context of neurological disease exists, it is a highly challenging endeavour because of the many levels of organization in the nervous system. This challenge is coupled with the increasing knowledge of cellular specificity and network dysfunction that is associated with disease. Recently, whole hippocampus in vitro preparations from control animals have been shown to spontaneously express oscillatory activities. In addition, when using preparations derived from animal models of disease, these activities show particular alterations. These preparations present an opportunity to address challenges involved with using models to gain insight because of easier access to simultaneous cellular and network measurements, and pharmacological modulations. We propose that by developing and using models with direct links to experiment at multiple levels, which at least include cellular and microcircuit, a cycling can be set up and used to help us determine critical mechanisms underlying neurological disease. We illustrate our proposal using our previously developed inhibitory network models in the context of these whole hippocampus preparations and show the importance of having direct links at multiple levels.

  18. Being an honest broker of hydrology: Uncovering, communicating and addressing model error in a climate change streamflow dataset

    Science.gov (United States)

    Chegwidden, O.; Nijssen, B.; Pytlak, E.

    2017-12-01

    Any model simulation has errors, including errors in meteorological data, process understanding, model structure, and model parameters. These errors may express themselves as bias, timing lags, and differences in sensitivity between the model and the physical world. The evaluation and handling of these errors can greatly affect the legitimacy, validity and usefulness of the resulting scientific product. In this presentation we will discuss a case study of handling and communicating model errors during the development of a hydrologic climate change dataset for the Pacific Northwestern United States. The dataset was the result of a four-year collaboration between the University of Washington, Oregon State University, the Bonneville Power Administration, the United States Army Corps of Engineers and the Bureau of Reclamation. Along the way, the partnership facilitated the discovery of multiple systematic errors in the streamflow dataset. Through an iterative review process, some of those errors could be resolved. For the errors that remained, honest communication of the shortcomings promoted the dataset's legitimacy. Thoroughly explaining errors also improved ways in which the dataset would be used in follow-on impact studies. Finally, we will discuss the development of the "streamflow bias-correction" step often applied to climate change datasets that will be used in impact modeling contexts. We will describe the development of a series of bias-correction techniques through close collaboration among universities and stakeholders. Through that process, both universities and stakeholders learned about the others' expectations and workflows. This mutual learning process allowed for the development of methods that accommodated the stakeholders' specific engineering requirements. The iterative revision process also produced a functional and actionable dataset while preserving its scientific merit. We will describe how encountering earlier techniques' pitfalls allowed us

  19. Modeling and simulation of a dual-junction CIGS solar cell using Silvaco ATLAS

    OpenAIRE

    Fotis, Konstantinos

    2012-01-01

    Approved for public release; distribution is unlimited. The potential of designing a dual-junction Copper Indium Gallium Selenide (CIGS) photovoltaic cell is investigated in this thesis. Research into implementing a dual-junction solar cell, using a CIGS bottom cell and different thin-film designs as a top cell, was conducted in order to increase the current record efficiency of 20.3% for a single CIGS cell. This was accomplished through modeling and simulation using Silvaco ATLASTM, an ad...

  20. Equilibrium, kinetic and reactive transport models for Pu: employing numerical methods to uncover the nature of the intrinsic colloid

    International Nuclear Information System (INIS)

    Schwantes, Jon M.; Batchelor, Bill

    2000-01-01

    Future missions for the Department of Defense include processing plutonium for vitrification and conversion to mixed oxide fuels for commercial use. Such processing could result in the production of Pu-containing waste and unplanned releases of Pu to the environment. Some releases related to plutonium processing have occurred in the past. However, scientists are currently not able to explain the observed behavior of plutonium in natural systems. For example, classical filtration theory predicts that plutonium transport within groundwater should be limited to a few tens of meters. Experimental observations, however, show that plutonium is present in groundwater at distances orders of magnitude farther away from its source than predicted. Before adequate disposal practices can be designed for plutonium, its behavior in these systems must be better understood. The overall goal of this project is to develop equilibrium, kinetic and reactive transport models that describe the behavior of Pu in aqueous systems and to apply these models to natural and engineered systems

  1. Poisson–Lie T-duals of the bi-Yang–Baxter models

    Energy Technology Data Exchange (ETDEWEB)

    Klimčík, Ctirad, E-mail: ctirad.klimcik@univ-amu.fr

    2016-09-10

    We prove the conjecture of Sfetsos, Siampos and Thompson that suitable analytic continuations of the Poisson–Lie T-duals of the bi-Yang–Baxter sigma models coincide with the recently introduced generalized λ-models. We then generalize this result by showing that the analytic continuation of a generic σ-model of “universal WZW-type” introduced by Tseytlin in 1993 is nothing but the Poisson–Lie T-dual of a generic Poisson–Lie symmetric σ-model introduced by Klimčík and Ševera in 1995.

  2. Prediction models for performance and emissions of a dual fuel CI ...

    Indian Academy of Sciences (India)

    use artificial intelligence modelling techniques like fuzzy logic, Artificial Neural Net- work (ANN), Genetic Algorithm (GA), etc. This paper uses a neuro fuzzy modelling technique, Adaptive Neuro Fuzzy Inference System (ANFIS) for developing predic- tion models for performance and emission parameter of a dual fuel engine.

  3. Modeling volume effects of experimental brachytherapy in the rat rectum: uncovering the limitations of a radiobiologic concept

    International Nuclear Information System (INIS)

    Johannessen, Hans-Olaf; Dale, Einar; Hellebust, Taran P.; Olsen, Dag R.; Nesland, Jahn M.; Giercksky, Karl-Erik

    2002-01-01

    Purpose: To analyze the significance of volume effects in experimental brachytherapy, based on modeling normal tissue complication probability. Methods and Materials: Experimental brachytherapy in the rat rectum was based on an eight-step 2.5-mm step size source configuration for 192 Ir, afterloaded into an unshielded polystyrene applicator. Volume effects were studied using a half-circumferential lead-shielded applicator and a shorter (two-step) source configuration. The main end point was rectal stenosis. Results: Rectal stenosis was always caused by a radiation ulcer. With the shielded configuration, single-dose ED 50 (50% incidence of rectal stenosis) increased from 23 Gy to 36.5 Gy. Single-dose ED 50 for the short configuration was 77.9 Gy. The data showed a reasonable fit to a three-parameter version of the biophysical model described by Jackson et al. (1995). This model assumes that organs consist of a large number of radiobiologically independent subunits and that radiation causes a complication if the fraction of the organ damaged is greater than its functional reserve. The fraction of the organ damaged is calculated summing over fractions of the organ damaged at each dose level. The calculated mean functional reserve (ν 50 ) of the rat rectum, assuming a cumulative functional reserve distribution in the group of experimental rats, was 0.53. Conclusions: The volume effect observed within small brachytherapy volumes agreed well with clinical experience of large tolerance doses in contact X-ray therapy. However, the ν 50 value was comparable to the high functional reserve value reported for liver. Experimental volume effects probably reflect repair processes originating in the areas adjacent to small radiation fields of brachytherapy more than the radiobiologic characteristics of the cells in the irradiated volume

  4. Thermal-oxidative effect of Kraft lignin antioxidant in polypropylene: Uncovering the key factor using correlation analysis model.

    Science.gov (United States)

    Chen, Kai; Ye, Dezhan; Gu, Shaojin; Zhou, Yingshan

    2018-02-01

    Which factors are crucial to improving lignin antioxidant ability in polymers has been debated over years. Here, the structural effect of natural antioxidant from technical Kraft lignin (KL) on the oxidation induction time (OIT) of KL/polypropylene (PP) was quantitatively investigated using correlation analysis model instead of traditional linear fitting model. The correlation coefficient and significance value of their relationship clearly demonstrated the dominating role of non-condensed Phenolic OH (Ph-OH) in improving KL/PP thermal-oxidation stability, subsequently followed by M¯ n , aliphatic OH/total Ph-OH, condensed Ph-OH and polydispersity. OIT is positive with non-condensed and total Ph-OH, while it declines with increase of the above other factors. Remarkably, the longest OIT (∼90min) was obtained even at extreme loading (0.5wt%), almost ∼911% and ∼201% huge increase in contrast to that of pure PP and crude KL/PP composite, respectively. Meanwhile, the mechanical properties of KL fractions/PP blends can be maintained at the same or better level than that of pure PP, due to strong interfacial adhesion strength. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. A realistic bi-hemispheric model of the cerebellum uncovers the purpose of the abundant granule cells during motor control.

    Science.gov (United States)

    Pinzon-Morales, Ruben-Dario; Hirata, Yutaka

    2015-01-01

    The cerebellar granule cells (GCs) have been proposed to perform lossless, adaptive spatio-temporal coding of incoming sensory/motor information required by downstream cerebellar circuits to support motor learning, motor coordination, and cognition. Here we use a physio-anatomically inspired bi-hemispheric cerebellar neuronal network (biCNN) to selectively enable/disable the output of GCs and evaluate the behavioral and neural consequences during three different control scenarios. The control scenarios are a simple direct current motor (1 degree of freedom: DOF), an unstable two-wheel balancing robot (2 DOFs), and a simulation model of a quadcopter (6 DOFs). Results showed that adequate control was maintained with a relatively small number of GCs (< 200) in all the control scenarios. However, the minimum number of GCs required to successfully govern each control plant increased with their complexity (i.e., DOFs). It was also shown that increasing the number of GCs resulted in higher robustness against changes in the initialization parameters of the biCNN model (i.e., synaptic connections and synaptic weights). Therefore, we suggest that the abundant GCs in the cerebellar cortex provide the computational power during the large repertoire of motor activities and motor plants the cerebellum is involved with, and bring robustness against changes in the cerebellar microcircuit (e.g., neuronal connections).

  6. A realistic bi-hemispheric model of the cerebellum uncovers the purpose of the abundant granule cells during motor control

    Directory of Open Access Journals (Sweden)

    Ruben Dario Pinzon Morales

    2015-05-01

    Full Text Available The cerebellar granule cells (GCs have been proposed to perform lossless, adaptive spatio-temporal coding of incoming sensory/motor information required by downstream cerebellar circuits to textcolor{red}{support} motor learning, motor coordination, and cognition. Here we use a physio-anatomically inspired bi-hemispheric cerebellar neuronal network (biCNN to selectively enable/disable the output of GCs and evaluate the behavioral and neural consequences during three different control scenarios. The control scenarios are a simple direct current motor (1 degree of freedom: DOF, an unstable two-wheel balancing robot (2 DOFs, and a simulation model of a quadcopter (6 DOFs. Results showed that adequate control was maintained with a relatively small number of GCs ($<$ 200 in all the control scenarios. However, the minimum number of GCs required to successfully govern each control plant increased with their complexity (i.e., DOFs. It was also shown that increasing the number of GCs resulted in higher robustness against changes in the initialization parameters of the biCNN model (i.e., synaptic connections and synaptic weights. Therefore, we suggest that the abundant GCs in the cerebellar cortex provide the computational power during the large repertoire of motor activities and motor plants the cerebellum is involved with, and bring robustness against changes in the cerebellar microcircuit (e.g., neuronal connections.

  7. Uncovering nonperturbative dynamics of the biased sub-Ohmic spin-boson model with variational matrix product states

    Science.gov (United States)

    Gonzalez-Ballestero, C.; Schröder, Florian A. Y. N.; Chin, Alex W.

    2017-09-01

    We study the dynamics of the biased sub-Ohmic spin-boson model by means of a time-dependent variational matrix product state (TDVMPS) algorithm. The evolution of both the system and the environment is obtained in the weak- and the strong-coupling regimes, respectively characterized by damped spin oscillations and by a nonequilibrium process where the spin freezes near its initial state, which are explicitly shown to arise from a variety of reactive environmental quantum dynamics. We also explore the rich phenomenology of the intermediate-coupling case, a nonperturbative regime where the system shows a complex dynamical behavior, combining features of both the weakly and the strongly coupled case in a sequential, time-retarded fashion. Our work demonstrates the potential of TDVMPS methods for exploring otherwise elusive, nonperturbative regimes of complex open quantum systems, and points to the possibilities of exploiting the qualitative, real-time modification of quantum properties induced by nonequilibrium bath dynamics in ultrafast transient processes.

  8. Integrated Hydrogeophysical and Hydrogeologic Driven Parameter Upscaling for Dual-Domain Transport Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Gregory Flach; Mary Harris; Susan Hubbard; Camelia Knapp; Mike Kowalsky; Maggie Millings; John Shafer; Mike Waddell

    2006-06-01

    Our research project is motivated by the observations that conventional characterization approaches capture only a fraction of heterogeneity affecting field-scale transport, and that conventional modeling approaches, which use this sparse data, typically do not successfully predict long term plume behavior with sufficient accuracy to guide remedial strategies. Our working hypotheses are that improved prediction of contaminant transport can be achieved using a dual-domain transport approach and field-scale characterization approaches. Our overall objectives are to: (1) develop a dual-domain modeling approach using the TOUGH2 family of codes that incorporates the key interactions between mobile and immobile transport regions that are expected to play a role in long term plume behavior; (2) develop a facies-based multi-scale characterization approach that utilizes log, crosshole, and surface-based characterization information and that is guided by the parameterization needs of the dual domain modeling; and (3) evaluate the approaches by applying them to the prediction of plume behavior at the P-Area at the Savannah River Site (Figure 1). Our three-year project scope includes development of multi-scale characterization and dual-domain modeling approach and field-scale data acquisition (Year 1); Numerical simulations and field-scale characterization (Year 2); and Plume transport simulations and exploration of optimal dual-domain parameters (Year 3).

  9. Pricing Model for Dual Sales Channel with Promotion Effect Consideration

    Directory of Open Access Journals (Sweden)

    Chuiri Zhou

    2016-01-01

    Full Text Available We focus on the pricing strategy of a dual sales channel member when his/her online retailer faces an upcoming overloaded express delivery service due to the sales peak of online shopping, especially referring to the occurring affairs in China. We characterize the pricing problem of the dual selling channel system as a two-period game. When the price discount is only provided by the online seller, we find that the prices of the traditional channel and the online channel in the two periods are higher while the overloaded degree of express delivery is lower and the overloaded delivery services can decrease the profits of both channels. When the price discounts are provided by both traditional and online sellers, we find that the derived Nash price equilibrium of both channels includes five possible combinations of prices. Both traditional and online sellers will choose their price strategies, respectively, according to their cost advantages which are affected by the overloaded degree of express delivery.

  10. Modeling and Control of a Dual-Input Isolated Full-Bridge Boost Converter

    DEFF Research Database (Denmark)

    Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael A. E.

    2012-01-01

    In this paper, a steady-state model, a large-signal (LS) model and an ac small-signal (SS) model for a recently proposed dual-input transformer-isolated boost converter are derived respectively by the switching flow-graph (SFG) nonlinear modeling technique. Based upon the converter’s model, the c....... The measured experimental results match the simulation results fairly well on both input source dynamic and step load transient responses....

  11. The dual pathway model of overeating. Replication and extension with actual food consumption

    NARCIS (Netherlands)

    Ouwens, M.A.; Strien, T. van; Leeuwe, J.F.J. van; Staak, C.P.F. van der

    2009-01-01

    van Strien et al. [van Strien, T., Engels, R. C. M. E., van Leeuwe, J., Snoek, H. M. (2005). The Stice model of overeating: tests in clinical and non-clinical samples. Appetite, 45, 205–213] extended the negative affect pathway of Stice's dual pathway model of overeating Stice [Stice, E. (1994).

  12. The dual pathway model of overeating. Replication and extension with actual food consumption

    NARCIS (Netherlands)

    Ouwens, Machteld A; van Strien, T; Leeuwe, J.F.J.; van der Staak, C P F

    van Strien et al. [van Strien, T., Engels, R. C. M. E., van Leeuwe, J., Snoek, H. M. (2005). The Stice model of overeating: tests in clinical and non-clinical samples. Appetite, 45, 205-213] extended the negative affect pathway of Stice's dual pathway model of overeating Stice [Stice, E. (1994).

  13. Beyond dual-process models: A categorisation of processes underlying intuitive judgement and decision making

    NARCIS (Netherlands)

    Glöckner, A.; Witteman, C.L.M.

    2010-01-01

    Intuitive-automatic processes are crucial for making judgements and decisions. The fascinating complexity of these processes has attracted many decision researchers, prompting them to start investigating intuition empirically and to develop numerous models. Dual-process models assume a clear

  14. Wiener model identification and predictive control for dual composition control of a distillation column

    NARCIS (Netherlands)

    Bloemen, H.H.J.; Chou, C.T.; van den Boom, T.J.J.; Verdult, V.; Verhaegen, M.H.G.; Backx, T.C.

    2001-01-01

    The benefits of using the Wiener model based identification and control methodology presented in this paper, compared to linear techniques, are demonstrated for dual composition control of a moderate–high purity distillation column simulation model. An identification experiment design is presented

  15. A Dual-Stage Two-Phase Model of Selective Attention

    Science.gov (United States)

    Hubner, Ronald; Steinhauser, Marco; Lehle, Carola

    2010-01-01

    The dual-stage two-phase (DSTP) model is introduced as a formal and general model of selective attention that includes both an early and a late stage of stimulus selection. Whereas at the early stage information is selected by perceptual filters whose selectivity is relatively limited, at the late stage stimuli are selected more efficiently on a…

  16. A Dual-Process Approach to Health Risk Decision Making: The Prototype Willingness Model

    Science.gov (United States)

    Gerrard, Meg; Gibbons, Frederick X.; Houlihan, Amy E.; Stock, Michelle L.; Pomery, Elizabeth A.

    2008-01-01

    Although dual-process models in cognitive, personality, and social psychology have stimulated a large body of research about analytic and heuristic modes of decision making, these models have seldom been applied to the study of adolescent risk behaviors. In addition, the developmental course of these two kinds of information processing, and their…

  17. Dual-Extrusion 3D Printing of Anatomical Models for Education

    Science.gov (United States)

    Smith, Michelle L.; Jones, James F. X.

    2018-01-01

    Two material 3D printing is becoming increasingly popular, inexpensive and accessible. In this paper, freely available printable files and dual extrusion fused deposition modelling were combined to create a number of functional anatomical models. To represent muscle and bone FilaFlex[superscript 3D] flexible filament and polylactic acid (PLA)…

  18. The Dual Half-Edge—A Topological Primal/Dual Data Structure and Construction Operators for Modelling and Manipulating Cell Complexes

    Directory of Open Access Journals (Sweden)

    Pawel Boguslawski

    2016-02-01

    Full Text Available There is an increasing need for building models that permit interior navigation, e.g., for escape route analysis. This paper presents a non-manifold Computer-Aided Design (CAD data structure, the dual half-edge based on the Poincaré duality that expresses both the geometric representations of individual rooms and their topological relationships. Volumes and faces are expressed as vertices and edges respectively in the dual space, permitting a model just based on the storage of primal and dual vertices and edges. Attributes may be attached to all of these entities permitting, for example, shortest path queries between specified rooms, or to the exterior. Storage costs are shown to be comparable to other non-manifold models, and construction with local Euler-type operators is demonstrated with two large university buildings. This is intended to enhance current developments in 3D Geographic Information Systems for interior and exterior city modelling.

  19. Development of a dual permeability model within a hydrological catchment modeling framework: 1D application.

    Science.gov (United States)

    Djabelkhir, K; Lauvernet, C; Kraft, P; Carluer, N

    2017-01-01

    Preferential flow contributes significantly to pesticide fast transfer from surface to groundwater. Modeling this process at several scales is an important challenge for improving the representation of this process which is often neglected. In this study, we developed a dual permeability approach in a hydrological modeling framework, CMF, which is a collaborative environment for developing spatially-integrated models of water fluxes. In the development we propose here, infiltration in macropores which are connected to the surface is activated when the first matrix layer reaches saturation. A transfer function is used to represent water fluxes from macropores to matrix. This approach is tested in 1D by comparison with the dual permeability approach included in Hydrus1D, on 4 typical soil-types (sandy-loam, silty-loam, clay-loam and sandy-clay-loam). The results showed an underestimation of the flux infiltrated in the matrix surface and important infiltration in macropores with the new model, for most of soil-types, comparing to Hydrus1D. Similarities are observed for fluxes transferred from macropores to matrix. Solute transport is then coupled to CMF-DP model considering a convection transport and a linear adsorption to represent pesticides behavior in macroporous soils. The approach we developed is similar to Hydrus though having the advantage to need less input parameters, especially for the exchange between the two porous media. In the future, it could be applied for predicting pesticides transfer in macroporous soils at different scales for operational applications. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Dynamics of dual prism adaptation: relating novel experimental results to a minimalistic neural model.

    Directory of Open Access Journals (Sweden)

    Orlando Arévalo

    Full Text Available In everyday life, humans interact with a dynamic environment often requiring rapid adaptation of visual perception and motor control. In particular, new visuo-motor mappings must be learned while old skills have to be kept, such that after adaptation, subjects may be able to quickly change between two different modes of generating movements ('dual-adaptation'. A fundamental question is how the adaptation schedule determines the acquisition speed of new skills. Given a fixed number of movements in two different environments, will dual-adaptation be faster if switches ('phase changes' between the environments occur more frequently? We investigated the dynamics of dual-adaptation under different training schedules in a virtual pointing experiment. Surprisingly, we found that acquisition speed of dual visuo-motor mappings in a pointing task is largely independent of the number of phase changes. Next, we studied the neuronal mechanisms underlying this result and other key phenomena of dual-adaptation by relating model simulations to experimental data. We propose a simple and yet biologically plausible neural model consisting of a spatial mapping from an input layer to a pointing angle which is subjected to a global gain modulation. Adaptation is performed by reinforcement learning on the model parameters. Despite its simplicity, the model provides a unifying account for a broad range of experimental data: It quantitatively reproduced the learning rates in dual-adaptation experiments for both direct effect, i.e. adaptation to prisms, and aftereffect, i.e. behavior after removal of prisms, and their independence on the number of phase changes. Several other phenomena, e.g. initial pointing errors that are far smaller than the induced optical shift, were also captured. Moreover, the underlying mechanisms, a local adaptation of a spatial mapping and a global adaptation of a gain factor, explained asymmetric spatial transfer and generalization of prism

  1. Refinement of the tripartite influence model for men: dual body image pathways to body change behaviors.

    Science.gov (United States)

    Tylka, Tracy L

    2011-06-01

    Although muscularity and body fat concerns are central to conceptualizing men's body image, they have not been examined together within existing structural models. This study refined the tripartite influence model (Thompson, Heinberg, Altabe, & Tantleff-Dunn, 1999) by including dual body image pathways (muscularity and body fat dissatisfaction) to engagement in muscular enhancement and disordered eating behaviors, respectively, and added dating partners as a source of social influence. Latent variable structural equation modeling analyses supported this quadripartite model in 473 undergraduate men. Nonsignificant paths were trimmed and two unanticipated paths were added. Muscularity dissatisfaction and body fat dissatisfaction represented dual body image pathways to men's engagement in muscularity enhancement behaviors and disordered eating behaviors, respectively. Pressures to be mesomorphic from friends, family, media, and dating partners made unique contributions to the model. Internalization of the mesomorphic ideal, muscularity dissatisfaction, and body fat dissatisfaction played key meditational roles within the model. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. A Dual Process Motivational Model of Ambivalent Sexism and Gender Differences in Romantic Partner Preferences

    Science.gov (United States)

    Sibley, Chris G.; Overall, Nickola C.

    2011-01-01

    We tested a dual process motivational model of ambivalent sexism and gender differences in intimate partner preferences. Meta-analysis of 32 samples (16 with men, 16 with women; N = 5,459) indicated that Benevolent Sexism (BS) in women was associated with greater preferences for high-resource partners (r = 0.24), whereas Hostile Sexism (HS) in men…

  3. Acting in solidarity : Testing an extended dual pathway model of collective action by bystander group members

    NARCIS (Netherlands)

    Saab, Rim; Tausch, Nicole; Spears, Russell; Cheung, Wing-Yee

    We examined predictors of collective action among bystander group members in solidarity with a disadvantaged group by extending the dual pathway model of collective action, which proposes one efficacy-based and one emotion-based path to collective action (Van Zomeren, Spears, Fischer, & Leach,

  4. Protesters as "passionate economists" : A dynamic dual pathway model of approach coping with collective disadvantage

    NARCIS (Netherlands)

    van Zomeren, Martijn; Leach, Colin Wayne; Spears, Russell

    To explain the psychology behind individuals' motivation to participate in collective action against collective disadvantage (e.g., protest marches), the authors introduce a dynamic dual pathway model of approach coping that integrates many common explanations of collective action (i.e., group

  5. Personality and creativity : The dual pathway to creativity model and a research agenda

    NARCIS (Netherlands)

    Baas, Matthijs; Roskes, Marieke; Sligte, Daniel; Nijstad, Bernard A.; De Dreu, Carsten K W

    2013-01-01

    To better understand the relation between personality traits and creativity, we invoke the Dual-Pathway to Creativity model (DPCM) that identifies two pathways to creative outcomes: (1) flexible processing of information (cognitive flexibility) and (2) persistent probing, and systematically and

  6. The dual pathway to creativity model : Creative ideation as a function of flexibility and persistence

    NARCIS (Netherlands)

    Nijstad, B.A.; De Dreu, C.K.W.; Rietzschel, E.F.; Baas, M.

    2010-01-01

    The dual pathway to creativity model argues that creativity-the generation of original and appropriate ideas-is a function of cognitive flexibility and cognitive persistence, and that dispositional or situational variables may influence creativity either through their effects on flexibility, on

  7. Personality and creativity: the Dual Pathway to Creativity model and a research agenda

    NARCIS (Netherlands)

    Baas, M.; Roskes, M.; Sligte, D.; Nijstad, B.A.; de Dreu, C.K.W.

    2013-01-01

    To better understand the relation between personality traits and creativity, we invoke the Dual-Pathway to Creativity model (DPCM) that identifies two pathways to creative outcomes: (1) flexible processing of information (cognitive flexibility) and (2) persistent probing, and systematically and

  8. Experimental evidence for a dual pathway model analysis of coping with the climate crisis

    NARCIS (Netherlands)

    van Zomeren, Martijn; Spears, Russell; Leach, Colinn Wayne

    2010-01-01

    Two experiments examined the psychological power of fear and group efficacy beliefs to increase environmental action intentions against the climate crisis Extending a dual pathway model of coping with collective disadvantage results showed evidence for emotion-focused approach coping Environmental

  9. Looking beyond Psychopathology: The Dual-Factor Model of Mental Health in Youth

    Science.gov (United States)

    Suldo, Shannon M.; Shaffer, Emily J.

    2008-01-01

    In a dual-factor model of mental health (cf. Greenspoon & Saklofske, 2001), assessments of positive indicators of wellness (i.e., subjective well-being--SWB) are coupled with traditional negative indicators of illness (i.e., psychopathology) to comprehensively measure mental health. The current study examined the existence and utility of a…

  10. On a relation between massive Yang-Mills theories and dual string models

    International Nuclear Information System (INIS)

    Mickelsson, J.

    1983-01-01

    The relations between mass terms in Yang-Mills theories, projective representations of the group of gauge transformations, boundary conditions on vector potentials and Schwinger terms in local charge algebra commutation relations are discussed. The commutation relations (with Schwinger terms) are similar to the current algebra commutation relations of the SU(N) extended dual string model. (orig.)

  11. How to Use COMSOL Multiphysics for coupled dual-permeability hydrological and slope stability modeling

    NARCIS (Netherlands)

    Shao, W.; Bogaard, T.A.; Bakker, M.

    2014-01-01

    Preferential flow paths, such as cracks, macropores, fissures, pipes etc. are common features of highly heterogeneous slopes. During intense rainstorms, preferential flow has a significant influence on subsurface flow and slope stability. Dual-permeability models are widely used to simulate

  12. Validation of standardized and structured EHR data in the dual model approach.

    Science.gov (United States)

    Rinner, Christoph; Duftschmid, Georg

    2009-01-01

    We present a W3C XML Schema-based method to validate standardized EHR data against semantic constraints that build the knowledge layer within the dual model approach. The approach was tested with three EN/ISO13606 archetypes and an HL7 CDA implementation guide for diabetes therapies.

  13. Leading a New Pedagogical Approach to Australian Curriculum Mathematics: Using the Dual Mathematical Modelling Cycle Framework

    Science.gov (United States)

    Lamb, Janeen; Kawakami, Takashi; Saeki, Akihiko; Matsuzaki, Akio

    2014-01-01

    The aim of this study was to investigate the use of the "dual mathematical modelling cycle framework" as one way to meet the espoused goals of the Australian Curriculum Mathematics. This study involved 23 Year 6 students from one Australian primary school who engaged in an "Oil Tank Task" that required them to develop two…

  14. A new compact subthreshold behavior model for dual-material surrounding gate (DMSG) MOSFETs

    Science.gov (United States)

    Chiang, T. K.

    2009-05-01

    On the basis of exact resultant solution of two-dimensional Poisson equation, a new compact subthreshold behavior model comprising two-dimensional potential, threshold voltage, subthreshold current and subthreshold swing for the dual-material surrounding gate (DMSG) MOSFETs is successfully developed. The model shows its validity by a good agreement with the simulated results from published device simulation software MEDICI. Besides offering the physical insight into device physics, the model provides the basic designing guidance for the DMSG MOSFETs.

  15. Phase-field modeling of corrosion kinetics under dual-oxidants

    Science.gov (United States)

    Wen, You-Hai; Chen, Long-Qing; Hawk, Jeffrey A.

    2012-04-01

    A phase-field model is proposed to simulate corrosion kinetics under a dual-oxidant atmosphere. It will be demonstrated that the model can be applied to simulate corrosion kinetics under oxidation, sulfidation and simultaneous oxidation/sulfidation processes. Phase-dependent diffusivities are incorporated in a natural manner and allow more realistic modeling as the diffusivities usually differ by many orders of magnitude in different phases. Simple free energy models are then used for testing the model while calibrated free energy models can be implemented for quantitative modeling.

  16. Modelling and measurement of wear particle flow in a dual oil filter system for condition monitoring

    DEFF Research Database (Denmark)

    Henneberg, Morten; Eriksen, René Lynge; Fich, Jens

    2016-01-01

    Wear debris is an indicator of the health of machinery, and the availability of accurate methods for characterising debris is important. In this work, a dual filter model for a gear oil system is used in conjunction with operational data to indicate three different system operating states...... boundary condition for particle burst phenomenon, the release of wear particles from a pleated mesh filter is measured in a test rig and included in the model. The findings show that a dual filter model, with startup phenomenon included, can describe trends in the wear particle flow observed in the gear...... oil. Using this model it is possible to draw conclusions on the filtration system performance and wear generation in the gears. Limitations of the proposed model are the lack of ability to describe noise and random burst spikes attributed to measurement error distributions. Trending of gear wear...

  17. Vertically-Integrated Dual-Continuum Models for CO2 Injection in Fractured Aquifers

    Science.gov (United States)

    Tao, Y.; Guo, B.; Bandilla, K.; Celia, M. A.

    2017-12-01

    Injection of CO2 into a saline aquifer leads to a two-phase flow system, with supercritical CO2 and brine being the two fluid phases. Various modeling approaches, including fully three-dimensional (3D) models and vertical-equilibrium (VE) models, have been used to study the system. Almost all of that work has focused on unfractured formations. 3D models solve the governing equations in three dimensions and are applicable to generic geological formations. VE models assume rapid and complete buoyant segregation of the two fluid phases, resulting in vertical pressure equilibrium and allowing integration of the governing equations in the vertical dimension. This reduction in dimensionality makes VE models computationally more efficient, but the associated assumptions restrict the applicability of VE model to formations with moderate to high permeability. In this presentation, we extend the VE and 3D models for CO2 injection in fractured aquifers. This is done in the context of dual-continuum modeling, where the fractured formation is modeled as an overlap of two continuous domains, one representing the fractures and the other representing the rock matrix. Both domains are treated as porous media continua and can be modeled by either a VE or a 3D formulation. The transfer of fluid mass between rock matrix and fractures is represented by a mass transfer function connecting the two domains. We have developed a computational model that combines the VE and 3D models, where we use the VE model in the fractures, which typically have high permeability, and the 3D model in the less permeable rock matrix. A new mass transfer function is derived, which couples the VE and 3D models. The coupled VE-3D model can simulate CO2 injection and migration in fractured aquifers. Results from this model compare well with a full-3D model in which both the fractures and rock matrix are modeled with 3D models, with the hybrid VE-3D model having significantly reduced computational cost. In

  18. The effect of inclusion of inlets in dual drainage modelling

    Science.gov (United States)

    Chang, Tsang-Jung; Wang, Chia-Ho; Chen, Albert S.; Djordjević, Slobodan

    2018-04-01

    In coupled sewer and surface flood modelling approaches, the flow process in gullies is often ignored although the overland flow is drained to sewer network via inlets and gullies. Therefore, the flow entering inlets is transferred to the sewer network immediately, which may lead to a different flood estimation than the reality. In this paper, we compared two modelling approach with and without considering the flow processes in gullies in the coupled sewer and surface modelling. Three historical flood events were adopted for model calibration and validation. The results showed that the inclusion of flow process in gullies can further improve the accuracy of urban flood modelling.

  19. Semianalytical Solution of the Nonlinear Dual-Porosity Flow Model with the Quadratic Pressure Gradient Term

    Directory of Open Access Journals (Sweden)

    Jiang-Tao Li

    2015-01-01

    Full Text Available The nonlinear dual-porosity flow model, specifically considering the quadratic pressure gradient term, wellbore storage coefficient, well skin factor, and interporosity flow of matrix to natural fractures, was established for well production in a naturally fractured formation and then solved using a semianalytical method, including Laplace transform and a transformation of the pressure function. Analytical solution of the model in Laplace space was converted to numerical solution in real space using Stehfest numerical inversion. Nonlinear flow process for well production in a naturally fractured formation with different external boundaries was simulated and analyzed using standard pressure curves. Influence of the quadratic pressure gradient coefficient on pressure curves was studied qualitatively and quantitatively in conditions of a group of fixed model parameters. The research results show that the semianalytical modelling method is applicable in simulating the nonlinear dual-porosity flow behavior.

  20. Dual-input two-compartment pharmacokinetic model of dynamic contrast-enhanced magnetic resonance imaging in hepatocellular carcinoma.

    Science.gov (United States)

    Yang, Jian-Feng; Zhao, Zhen-Hua; Zhang, Yu; Zhao, Li; Yang, Li-Ming; Zhang, Min-Ming; Wang, Bo-Yin; Wang, Ting; Lu, Bao-Chun

    2016-04-07

    To investigate the feasibility of a dual-input two-compartment tracer kinetic model for evaluating tumorous microvascular properties in advanced hepatocellular carcinoma (HCC). From January 2014 to April 2015, we prospectively measured and analyzed pharmacokinetic parameters [transfer constant (Ktrans), plasma flow (Fp), permeability surface area product (PS), efflux rate constant (kep), extravascular extracellular space volume ratio (ve), blood plasma volume ratio (vp), and hepatic perfusion index (HPI)] using dual-input two-compartment tracer kinetic models [a dual-input extended Tofts model and a dual-input 2-compartment exchange model (2CXM)] in 28 consecutive HCC patients. A well-known consensus that HCC is a hypervascular tumor supplied by the hepatic artery and the portal vein was used as a reference standard. A paired Student's t-test and a nonparametric paired Wilcoxon rank sum test were used to compare the equivalent pharmacokinetic parameters derived from the two models, and Pearson correlation analysis was also applied to observe the correlations among all equivalent parameters. The tumor size and pharmacokinetic parameters were tested by Pearson correlation analysis, while correlations among stage, tumor size and all pharmacokinetic parameters were assessed by Spearman correlation analysis. The Fp value was greater than the PS value (FP = 1.07 mL/mL per minute, PS = 0.19 mL/mL per minute) in the dual-input 2CXM; HPI was 0.66 and 0.63 in the dual-input extended Tofts model and the dual-input 2CXM, respectively. There were no significant differences in the kep, vp, or HPI between the dual-input extended Tofts model and the dual-input 2CXM (P = 0.524, 0.569, and 0.622, respectively). All equivalent pharmacokinetic parameters, except for ve, were correlated in the two dual-input two-compartment pharmacokinetic models; both Fp and PS in the dual-input 2CXM were correlated with Ktrans derived from the dual-input extended Tofts model (P = 0.002, r = 0.566; P

  1. Uncovering the Hidden Routes

    DEFF Research Database (Denmark)

    Tsirogiannis, Constantinos; Tsirogiannis, Christos

    2016-01-01

    In the present work we model and analyse the global network of the illegal trade in antiquities. Our goal is to use this network to estimate for any given artefact the potential sequence of people in the network among whom this artefact was traded. For this reason, we have implemented and evaluat...

  2. Uncovering dynamic fault trees

    NARCIS (Netherlands)

    Junges, Sebastian; Guck, Dennis; Katoen, Joost P.; Stoelinga, Mariëlle Ida Antoinette

    Fault tree analysis is a widespread industry standard for assessing system reliability. Standard (static) fault trees model the failure behaviour of systems in dependence of their component failures. To overcome their limited expressive power, common dependability patterns, such as spare management,

  3. Comparison of Kinetic Models for Dual-Tracer Receptor Concentration Imaging in Tumors

    Science.gov (United States)

    Hamzei, Nazanin; Samkoe, Kimberley S; Elliott, Jonathan T; Holt, Robert W; Gunn, Jason R; Hasan, Tayyaba; Pogue, Brian W; Tichauer, Kenneth M

    2014-01-01

    Molecular differences between cancerous and healthy tissue have become key targets for novel therapeutics specific to tumor receptors. However, cancer cell receptor expression can vary within and amongst different tumors, making strategies that can quantify receptor concentration in vivo critical for the progression of targeted therapies. Recently a dual-tracer imaging approach capable of providing quantitative measures of receptor concentration in vivo was developed. It relies on the simultaneous injection and imaging of receptor-targeted tracer and an untargeted tracer (to account for non-specific uptake of the targeted tracer). Early implementations of this approach have been structured on existing “reference tissue” imaging methods that have not been optimized for or validated in dual-tracer imaging. Using simulations and mouse tumor model experimental data, the salient findings in this study were that all widely used reference tissue kinetic models can be used for dual-tracer imaging, with the linearized simplified reference tissue model offering a good balance of accuracy and computational efficiency. Moreover, an alternate version of the full two-compartment reference tissue model can be employed accurately by assuming that the K1s of the targeted and untargeted tracers are similar to avoid assuming an instantaneous equilibrium between bound and free states (made by all other models). PMID:25414912

  4. Self-dual configurations in Abelian Higgs models with k-generalized gauge field dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Casana, R.; Cavalcante, A. [Departamento de Física, Universidade Federal do Maranhão,65080-805, São Luís, Maranhão (Brazil); Hora, E. da [Departamento de Física, Universidade Federal do Maranhão,65080-805, São Luís, Maranhão (Brazil); Coordenadoria Interdisciplinar de Ciência e Tecnologia, Universidade Federal do Maranhão,65080-805, São Luís, Maranhão (Brazil)

    2016-12-14

    We have shown the existence of self-dual solutions in new Maxwell-Higgs scenarios where the gauge field possesses a k-generalized dynamic, i.e., the kinetic term of gauge field is a highly nonlinear function of F{sub μν}F{sup μν}. We have implemented our proposal by means of a k-generalized model displaying the spontaneous symmetry breaking phenomenon. We implement consistently the Bogomol’nyi-Prasad-Sommerfield formalism providing highly nonlinear self-dual equations whose solutions are electrically neutral possessing total energy proportional to the magnetic flux. Among the infinite set of possible configurations, we have found families of k-generalized models whose self-dual equations have a form mathematically similar to the ones arising in the Maxwell-Higgs or Chern-Simons-Higgs models. Furthermore, we have verified that our proposal also supports infinite twinlike models with |ϕ|{sup 4}-potential or |ϕ|{sup 6}-potential. With the aim to show explicitly that the BPS equations are able to provide well-behaved configurations, we have considered a test model in order to study axially symmetric vortices. By depending of the self-dual potential, we have shown that the k-generalized model is able to produce solutions that for long distances have a exponential decay (as Abrikosov-Nielsen-Olesen vortices) or have a power-law decay (characterizing delocalized vortices). In all cases, we observe that the generalization modifies the vortex core size, the magnetic field amplitude and the bosonic masses but the total energy remains proportional to the quantized magnetic flux.

  5. Multiple Model Adaptive Control Using Dual Youla-Kucera Factorisation

    DEFF Research Database (Denmark)

    Bendtsen, Jan Dimon; Trangbæk, Klaus

    2012-01-01

    We propose a multi-model adaptive control scheme for uncertain linear plants based on the concept of model unfalsification. The approach relies on examining the ability of a pre-computed set of plant-controller candidates and choosing the one that is best able to reproduce observed in- and output...... signal samples. The ability to reproduce observations is measured as an easily computable signal norm. Compared to other related approaches, our procedure is designed to be able to handle significant measurement noise and closed-loop correlations between output measurements and control signals....

  6. Dual states estimation of a subsurface flow-transport coupled model using ensemble Kalman filtering

    KAUST Repository

    El Gharamti, Mohamad

    2013-10-01

    Modeling the spread of subsurface contaminants requires coupling a groundwater flow model with a contaminant transport model. Such coupling may provide accurate estimates of future subsurface hydrologic states if essential flow and contaminant data are assimilated in the model. Assuming perfect flow, an ensemble Kalman filter (EnKF) can be used for direct data assimilation into the transport model. This is, however, a crude assumption as flow models can be subject to many sources of uncertainty. If the flow is not accurately simulated, contaminant predictions will likely be inaccurate even after successive Kalman updates of the contaminant model with the data. The problem is better handled when both flow and contaminant states are concurrently estimated using the traditional joint state augmentation approach. In this paper, we introduce a dual estimation strategy for data assimilation into a one-way coupled system by treating the flow and the contaminant models separately while intertwining a pair of distinct EnKFs, one for each model. The presented strategy only deals with the estimation of state variables but it can also be used for state and parameter estimation problems. This EnKF-based dual state-state estimation procedure presents a number of novel features: (i) it allows for simultaneous estimation of both flow and contaminant states in parallel; (ii) it provides a time consistent sequential updating scheme between the two models (first flow, then transport); (iii) it simplifies the implementation of the filtering system; and (iv) it yields more stable and accurate solutions than does the standard joint approach. We conducted synthetic numerical experiments based on various time stepping and observation strategies to evaluate the dual EnKF approach and compare its performance with the joint state augmentation approach. Experimental results show that on average, the dual strategy could reduce the estimation error of the coupled states by 15% compared with the

  7. One dimensional modeling of a diesel-CNG dual fuel engine

    Science.gov (United States)

    Azman, Putera Adam; Fawzi, Mas; Ismail, Muammar Mukhsin; Osman, Shahrul Azmir

    2017-04-01

    Some of the previous studies have shown that the use of compressed natural gas (CNG) in diesel engines potentially produce engine performance improvement and exhaust gas emission reduction, especially nitrogen oxides, unburned hydrocarbons, and carbon dioxide. On the other hand, there are other researchers who claimed that the use of CNG increases exhaust gas emissions, particularly nitrogen oxides. In this study, a one-dimensional model of a diesel-CNG dual fuel engine was made based on a 4-cylinder 2.5L common rail direct injection diesel engine. The software used is GT-Power, and it was used to analyze the engine performance and exhaust gas emissions of several diesel-CNG dual fuel blend ratios, i.e. 100:0, 90:10, 80:20, 70:30, 60:40 and 50:50. The effect of 100%, 75%, 50% engine loads on the exhaust gas emissions were also studied. The result shows that all diesel-CNG fuel blends produces higher brake torque and brake power at engine speed of 2000-3000 rpm compared with 100% diesel. The 50:50 diesel-CNG blend produces the highest brake torque and brake power, but also has the highest brake specific fuel consumption. As a higher percentage of CNG added to the dual fuel blend, unburned hydrocarbons and carbon monoxide emission increased while carbon dioxide emission decreased. The nitrogen oxides emission concentration is generally unaffected by any change of the dual fuel ratio.

  8. Photoproduction within the two-component Dual Parton Model: amplitudes and cross sections

    International Nuclear Information System (INIS)

    Engel, R.; Siegen Univ.

    1995-01-01

    In the framework of the Dual Parton Model an approximation scheme to describe high energy photoproduction processes is presented. Based on the distinction between direct, resolved soft, and resolved hard interaction processes we construct effective impact parameter amplitudes. In order to treat low mass diffraction within the eikonal formalism in a consistent way a phenomenological ansatz is proposed. The free parameters of the model are determined by fits to high energy hadro- and photoproduction cross sections. We calculate the partial photoproduction cross sections and discuss predictions of the model at HERA energies. Using hadro- and photoproduction data together, the uncertainties of the model predictions are strongly reduced. (orig.)

  9. A multiple fractal model for estimating permeability of dual-porosity media

    Science.gov (United States)

    Li, Bo; Liu, Richeng; Jiang, Yujing

    2016-09-01

    A multiple fractal model that considers the fractal properties of both porous matrices and fracture networks is proposed for the permeability of dual-porosity media embedded with randomly distributed fractures. In this model, the aperture distribution is verified to follow the fractal scaling law, and the porous matrix is assumed to comprise a bundle of tortuous capillaries that also follow the fractal scaling law. Analytical expressions for fractal aperture distribution, total flow rate, total equivalent permeability, and dimensionless permeability are established, where the dimensionless permeability is defined as the ratio of permeability of the porous matrices to that of the fracture networks. The dimensionless permeability is closely correlated to the structural parameters (i.e., α, θ, Dtf, Dtp, De, Dp, emax, λmax) of the dual-porosity media, and it is more sensitive to the fractal dimension for the size distribution of fracture aperture than to that for the size distribution of pore/capillary diameter. The maximum pore/capillary diameter has a greater impact on the dimensionless permeability than that of the maximum fracture aperture. The dimensionless permeability of fracture networks constructed by the fractal aperture distribution has close values with those of models with lognormal aperture distribution. The proposed multiple fractal model does not involve any empirical constants that do not have clear physical meanings, which could serve as a quick estimation method for assessing permeability of dual-porosity media.

  10. Uncovering Black Womanhood in Engineering

    Science.gov (United States)

    Gibson, Sheree L.; Espino, Michelle M.

    2016-01-01

    Despite the growing research that outlines the experiences of Blacks and women undergraduates in engineering, little is known about Black women in this field. The purpose of this qualitative study was to uncover how eight Black undergraduate women in engineering understood their race and gender identities in a culture that can be oppressive to…

  11. THE LOW FREQUENCY OF DUAL ACTIVE GALACTIC NUCLEI VERSUS THE HIGH MERGER RATE OF GALAXIES: A PHENOMENOLOGICAL MODEL

    International Nuclear Information System (INIS)

    Yu Qingjuan; Lu Youjun; Mohayaee, Roya; Colin, Jacques

    2011-01-01

    Dual active galactic nuclei (AGNs) are natural byproducts of hierarchical mergers of galaxies in the ΛCDM cosmogony. Recent observations have shown that only a small fraction (∼0.1%-2.5%) of AGNs at redshift z ∼< 0.3 are dual with kpc-scale separations, which is rather low compared to the high merger rate of galaxies. Here we construct a phenomenological model to estimate the number density of dual AGNs and its evolution according to the observationally estimated major merger rates of galaxies and various scaling relations on the properties of galaxies and their central massive black holes. We show that our model reproduces the observed frequency and separation distribution of dual AGNs provided that significant nuclear activities are triggered only in gas-rich progenitor galaxies with central massive black holes and only when the nuclei of these galaxies are roughly within the half-light radii of their companion galaxies. Under these constraints, the observed low dual AGN frequency is consistent with the relatively high merger rate of galaxies and supports the hypothesis that major mergers lead to AGN/QSO activities. We also predict that the number of kpc-scale dual AGNs decreases with increasing redshift and only about 0.02%-0.06% of AGNs are dual AGNs with double-peaked narrow line features at redshifts of z ∼ 0.5-1.2. Future observations of high-redshift dual AGNs would provide a solid test for this prediction.

  12. Design, Fabrication, and Modeling of a Novel Dual-Axis Control Input PZT Gyroscope

    Directory of Open Access Journals (Sweden)

    Cheng-Yang Chang

    2017-10-01

    Full Text Available Conventional gyroscopes are equipped with a single-axis control input, limiting their performance. Although researchers have proposed control algorithms with dual-axis control inputs to improve gyroscope performance, most have verified the control algorithms through numerical simulations because they lacked practical devices with dual-axis control inputs. The aim of this study was to design a piezoelectric gyroscope equipped with a dual-axis control input so that researchers may experimentally verify those control algorithms in future. Designing a piezoelectric gyroscope with a dual-axis control input is more difficult than designing a conventional gyroscope because the control input must be effective over a broad frequency range to compensate for imperfections, and the multiple mode shapes in flexural deformations complicate the relation between flexural deformation and the proof mass position. This study solved these problems by using a lead zirconate titanate (PZT material, introducing additional electrodes for shielding, developing an optimal electrode pattern, and performing calibrations of undesired couplings. The results indicated that the fabricated device could be operated at 5.5±1 kHz to perform dual-axis actuations and position measurements. The calibration of the fabricated device was completed by system identifications of a new dynamic model including gyroscopic motions, electromechanical coupling, mechanical coupling, electrostatic coupling, and capacitive output impedance. Finally, without the assistance of control algorithms, the “open loop sensitivity” of the fabricated gyroscope was 1.82 μV/deg/s with a nonlinearity of 9.5% full-scale output. This sensitivity is comparable with those of other PZT gyroscopes with single-axis control inputs.

  13. Design, Fabrication, and Modeling of a Novel Dual-Axis Control Input PZT Gyroscope.

    Science.gov (United States)

    Chang, Cheng-Yang; Chen, Tsung-Lin

    2017-10-31

    Conventional gyroscopes are equipped with a single-axis control input, limiting their performance. Although researchers have proposed control algorithms with dual-axis control inputs to improve gyroscope performance, most have verified the control algorithms through numerical simulations because they lacked practical devices with dual-axis control inputs. The aim of this study was to design a piezoelectric gyroscope equipped with a dual-axis control input so that researchers may experimentally verify those control algorithms in future. Designing a piezoelectric gyroscope with a dual-axis control input is more difficult than designing a conventional gyroscope because the control input must be effective over a broad frequency range to compensate for imperfections, and the multiple mode shapes in flexural deformations complicate the relation between flexural deformation and the proof mass position. This study solved these problems by using a lead zirconate titanate (PZT) material, introducing additional electrodes for shielding, developing an optimal electrode pattern, and performing calibrations of undesired couplings. The results indicated that the fabricated device could be operated at 5.5±1 kHz to perform dual-axis actuations and position measurements. The calibration of the fabricated device was completed by system identifications of a new dynamic model including gyroscopic motions, electromechanical coupling, mechanical coupling, electrostatic coupling, and capacitive output impedance. Finally, without the assistance of control algorithms, the "open loop sensitivity" of the fabricated gyroscope was 1.82 μV/deg/s with a nonlinearity of 9.5% full-scale output. This sensitivity is comparable with those of other PZT gyroscopes with single-axis control inputs.

  14. Cooperative Rendezvous and Docking for Underwater Robots Using Model Predictive Control and Dual Decomposition

    DEFF Research Database (Denmark)

    Nielsen, Mikkel Cornelius; Johansen, Tor Arne; Blanke, Mogens

    2018-01-01

    This paper considers the problem of rendezvous and docking with visual constraints in the context of underwater robots with camera-based navigation. The objective is the convergence of the vehicles to a common point while maintaining visual contact. The proposed solution includes the design of a ...... of a distributed model predictive controller based on dual decomposition, which allows for optimization in a decentralized fashion. The proposed distributed controller enables rendezvous and docking between vehicles while maintaining visual contact....

  15. Integrated Hydrogeophysical and Hydrogeologic Driven Parameter Upscaling for Dual-Domain Transport Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Gregory Flach; Mary Harris; Susan Hubbard; Camelia Knapp; Mike Kowalsky; Maggie Millings; John Shafer; Mike Waddell

    2006-06-01

    Our research project is motivated by the observations that conventional characterization approaches capture only a fraction of heterogeneity affecting field-scale transport, and that conventional modeling approaches, which use this sparse data, typically do not successfully predict long term plume behavior with sufficient accuracy to guide remedial strategies. Our working hypotheses are that improved prediction of contaminant transport can be achieved using a dual-domain transport approach and field-scale characterization approaches.

  16. Analyses of Spring Barley Evapotranspiration Rates Based on Gradient Measurements and Dual Crop Coefficient Model

    Czech Academy of Sciences Publication Activity Database

    Pozníková, Gabriela; Fischer, Milan; Pohanková, Eva; Trnka, Miroslav

    2014-01-01

    Roč. 62, č. 5 (2014), s. 1079-1086 ISSN 1211-8516 R&D Projects: GA MŠk LH12037; GA MŠk(CZ) EE2.3.20.0248 Institutional support: RVO:67179843 Keywords : evapotranspiration * dual crop coefficient model * Bowen ratio/energy balance method * transpiration * soil evaporation * spring barley Subject RIV: EH - Ecology, Behaviour OBOR OECD: Environmental sciences (social aspects to be 5.7)

  17. Dynamic modeling of dual-arm cooperating manipulators based on Udwadia–Kalaba equation

    Directory of Open Access Journals (Sweden)

    Jia Liu

    2016-07-01

    Full Text Available Dual-arm cooperating manipulators subject to a certain constraint brought about by the desired trajectory and geometric constraint show high nonlinearity and coupling in their dynamic characteristic. Therefore, it is hard to build dynamical equation with traditional Lagrange equation. The Udwadia–Kalaba equation presents a new idea of dynamic modeling of multi-body systems. However, the dynamic modeling of the unconstrained systems still depends on the traditional Lagrange equation and is quite tedious for dual-arm cooperating manipulators. A generalized dynamical equation of multi-link planar manipulators is thus presented and proven to make modeling conveniently. The constraint relationship is established from a new perspective, and the dynamical equation of dual-arm cooperating manipulator subject to the desired trajectory is acquired with the Udwadia–Kalaba equation. The simple approach overcomes the disadvantage of obtaining dynamical equation from traditional Lagrange equation by Lagrange multiplier. The simulation results of varying law of the joint angles and the motion path of the bar prove that the dynamical equation established by this method conforms to reality.

  18. Reliable Dual Tensor Model Estimation in Single and Crossing Fibers Based on Jeffreys Prior

    Science.gov (United States)

    Yang, Jianfei; Poot, Dirk H. J.; Caan, Matthan W. A.; Su, Tanja; Majoie, Charles B. L. M.; van Vliet, Lucas J.; Vos, Frans M.

    2016-01-01

    Purpose This paper presents and studies a framework for reliable modeling of diffusion MRI using a data-acquisition adaptive prior. Methods Automated relevance determination estimates the mean of the posterior distribution of a rank-2 dual tensor model exploiting Jeffreys prior (JARD). This data-acquisition prior is based on the Fisher information matrix and enables the assessment whether two tensors are mandatory to describe the data. The method is compared to Maximum Likelihood Estimation (MLE) of the dual tensor model and to FSL’s ball-and-stick approach. Results Monte Carlo experiments demonstrated that JARD’s volume fractions correlated well with the ground truth for single and crossing fiber configurations. In single fiber configurations JARD automatically reduced the volume fraction of one compartment to (almost) zero. The variance in fractional anisotropy (FA) of the main tensor component was thereby reduced compared to MLE. JARD and MLE gave a comparable outcome in data simulating crossing fibers. On brain data, JARD yielded a smaller spread in FA along the corpus callosum compared to MLE. Tract-based spatial statistics demonstrated a higher sensitivity in detecting age-related white matter atrophy using JARD compared to both MLE and the ball-and-stick approach. Conclusions The proposed framework offers accurate and precise estimation of diffusion properties in single and dual fiber regions. PMID:27760166

  19. Modeling the dual pacemaker system of the tau mutant hamster.

    Science.gov (United States)

    Oda, G A; Menaker, M; Friesen, W O

    2000-06-01

    Circadian pacemakers in many animals are compound. In rodents, a two-oscillator model of the pacemaker composed of an evening (E) and a morning (M) oscillator has been proposed based on the phenomenon of "splitting" and bimodal activity peaks. The authors describe computer simulations of the pacemaker in tau mutant hamsters viewed as a system of mutually coupled E and M oscillators. These mutant animals exhibit normal type 1 PRCs when released into DD but make a transition to a type 0 PRC when held for many weeks in DD. The two-oscillator model describes particularly well some recent behavioral experiments on these hamsters. The authors sought to determine the relationships between oscillator amplitude, period, PRC, and activity duration through computer simulations. Two complementary approaches proved useful for analyzing weakly coupled oscillator systems. The authors adopted a "distinct oscillators" view when considering the component E and M oscillators and a "system" view when considering the system as a whole. For strongly coupled systems, only the system view is appropriate. The simulations lead the authors to two primary conjectures: (1) the total amplitude of the pacemaker system in tau mutant hamsters is less than in the wild-type animals, and (2) the coupling between the unit E and M oscillators is weakened during continuous exposure of hamsters to DD. As coupling strength decreases, activity duration (alpha) increases due to a greater phase difference between E and M. At the same time, the total amplitude of the system decreases, causing an increase in observable PRC amplitudes. Reduced coupling also increases the relative autonomy of the unit oscillators. The relatively autonomous phase shifts of E and M oscillators can account for both immediate compression and expansion of activity bands in tau mutant and wild-type hamsters subjected to light pulses.

  20. Modelling and analysis of the transformer current resonance in dual active bridge converters

    DEFF Research Database (Denmark)

    Qin, Zian; Shen, Zhan; Blaabjerg, Frede

    2017-01-01

    . In order to study the generation mechanism of this current resonance, the impedance of the transformer and inductor with parasitic components is modelled in this digest. Then, based on the impedance model, an approach is proposed to mitigate the current resonance. Finally, both the impedance model......Due to the parasitic capacitances of the transformer and inductor in Dual Active Bridge (DAB) converters, resonance happens in the transformer currents. This high frequency resonant current flowing into the full bridges will worsen their soft-switching performance and thereby reduce its efficiency...

  1. Dual-process models of health-related behaviour and cognition: a review of theory.

    Science.gov (United States)

    Houlihan, S

    2018-03-01

    The aim of this review was to synthesise a spectrum of theories incorporating dual-process models of health-related behaviour. Review of theory, adapted loosely from Cochrane-style systematic review methodology. Inclusion criteria were specified to identify all relevant dual-process models that explain decision-making in the context of decisions made about human health. Data analysis took the form of iterative template analysis (adapted from the conceptual synthesis framework used in other reviews of theory), and in this way theories were synthesised on the basis of shared theoretical constructs and causal pathways. Analysis and synthesis proceeded in turn, instead of moving uni-directionally from analysis of individual theories to synthesis of multiple theories. Namely, the reviewer considered and reconsidered individual theories and theoretical components in generating the narrative synthesis' main findings. Drawing on systematic review methodology, 11 electronic databases were searched for relevant dual-process theories. After de-duplication, 12,198 records remained. Screening of title and abstract led to the exclusion of 12,036 records, after which 162 full-text records were assessed. Of those, 21 records were included in the review. Moving back and forth between analysis of individual theories and the synthesis of theories grouped on the basis of theme or focus yielded additional insights into the orientation of a theory to an individual. Theories could be grouped in part on their treatment of an individual as an irrational actor, as social actor, as actor in a physical environment or as a self-regulated actor. Synthesising identified theories into a general dual-process model of health-related behaviour indicated that such behaviour is the result of both propositional and unconscious reasoning driven by an individual's response to internal cues (such as heuristics, attitude and affect), physical cues (social and physical environmental stimuli) as well as

  2. Religion, fertility and genes: a dual inheritance model.

    Science.gov (United States)

    Rowthorn, Robert

    2011-08-22

    Religious people nowadays have more children on average than their secular counterparts. This paper uses a simple model to explore the evolutionary implications of this difference. It assumes that fertility is determined entirely by culture, whereas subjective predisposition towards religion is influenced by genetic endowment. People who carry a certain 'religiosity' gene are more likely than average to become or remain religious. The paper considers the effect of religious defections and exogamy on the religious and genetic composition of society. Defections reduce the ultimate share of the population with religious allegiance and slow down the spread of the religiosity gene. However, provided the fertility differential persists, and people with a religious allegiance mate mainly with people like themselves, the religiosity gene will eventually predominate despite a high rate of defection. This is an example of 'cultural hitch-hiking', whereby a gene spreads because it is able to hitch a ride with a high-fitness cultural practice. The theoretical arguments are supported by numerical simulations.

  3. Religion, fertility and genes: a dual inheritance model

    Science.gov (United States)

    Rowthorn, Robert

    2011-01-01

    Religious people nowadays have more children on average than their secular counterparts. This paper uses a simple model to explore the evolutionary implications of this difference. It assumes that fertility is determined entirely by culture, whereas subjective predisposition towards religion is influenced by genetic endowment. People who carry a certain ‘religiosity’ gene are more likely than average to become or remain religious. The paper considers the effect of religious defections and exogamy on the religious and genetic composition of society. Defections reduce the ultimate share of the population with religious allegiance and slow down the spread of the religiosity gene. However, provided the fertility differential persists, and people with a religious allegiance mate mainly with people like themselves, the religiosity gene will eventually predominate despite a high rate of defection. This is an example of ‘cultural hitch-hiking’, whereby a gene spreads because it is able to hitch a ride with a high-fitness cultural practice. The theoretical arguments are supported by numerical simulations. PMID:21227968

  4. Probabilistic Modeling of Seismic Risk Based Design for a Dual System Structure

    Directory of Open Access Journals (Sweden)

    Indra Djati Sidi

    2017-04-01

    Full Text Available The dual system structure concept has gained popularity in the construction of high-rise buildings over the last decades. Meanwhile, earthquake engineering design provisions for buildings have moved from the uniform hazard concept to the uniform risk concept upon recognizing the uncertainties involved in the earthquake resistance of concrete structures. In this study, a probabilistic model for the evaluation of such risk is proposed for a dual system structure consisting of shear walls or core walls and a moment frame structure as earthquake resistant structure. Uncertainties in the earthquake resistance of the dual system structure due to record-to-record variability, limited amount of data, material variability and structure modeling are included in the formulation by means of the first-order second-moment method. The statistics of resistance against earthquake forces are estimated by making use of incremental nonlinear time history analysis using 10 recorded earthquake histories. Then, adopting the total probability theorem, the reliability of the structure is evaluated through a risk integral scheme by combining the earthquake resistance of the structure with the annual probability of exceedance for a given location where the building is being constructed.

  5. Modelling and performance analysis of dual-channel switched reluctance motor

    Directory of Open Access Journals (Sweden)

    Bogusz Piotr

    2015-03-01

    Full Text Available The paper is a presentation of an analysis concerning performance of a 12/8 dual-channel switched reluctance motor (DCSRM. Formulas constituting a base for a non-linear mathematical model of DCSRM are presented. Simulation and laboratory tests were carried out for the motor operating in the dual-channel and single-channel mode. The results of the field theory-based calculations are presented in the form of fluxes in individual phases expressed as functions of currents and a rotor position angle. The results of the computer simulations are shown as the static characteristics of fluxes and the torque as well as voltage, current, and torque waveforms. The results of the laboratory tests are also presented.

  6. Higher Representations Duals

    DEFF Research Database (Denmark)

    Sannino, Francesco

    2010-01-01

    We uncover novel solutions of the 't Hooft anomaly matching conditions for scalarless gauge theories with matter transforming according to higher dimensional representations of the underlying gauge group. We argue that, if the duals exist, they are gauge theories with fermions transforming accord......-Dyson approximation. We use the solutions to gain useful insight on the conformal window of the associated electric theory. A consistent picture emerges corroborating previous results obtained via different analytic methods and in agreement with first principle lattice explorations....

  7. A Sound Processor for Cochlear Implant Using a Simple Dual Path Nonlinear Model of Basilar Membrane

    Directory of Open Access Journals (Sweden)

    Kyung Hwan Kim

    2013-01-01

    Full Text Available We propose a new active nonlinear model of the frequency response of the basilar membrane in biological cochlea called the simple dual path nonlinear (SDPN model and a novel sound processing strategy for cochlear implants (CIs based upon this model. The SDPN model was developed to utilize the advantages of the level-dependent frequency response characteristics of the basilar membrane for robust formant representation under noisy conditions. In comparison to the dual resonance nonlinear model (DRNL which was previously proposed as an active nonlinear model of the basilar membrane, the SDPN model can reproduce similar level-dependent frequency responses with a much simpler structure and is thus better suited for incorporation into CI sound processors. By the analysis of dominant frequency component, it was confirmed that the formants of speech are more robustly represented after frequency decomposition by the nonlinear filterbank using SDPN, compared to a linear bandpass filter array which is used in conventional strategies. Acoustic simulation and hearing experiments in subjects with normal hearing showed that the proposed strategy results in better syllable recognition under speech-shaped noise compared to the conventional strategy based on fixed linear bandpass filters.

  8. O(n) relations for coupling constants and space-time dimensions in dual models

    CERN Document Server

    Frampton, Paul H

    1972-01-01

    It is proposed that certain daughter trajectories arise as a consequence of a higher underlying O(n) symmetry, with n>3. This suggestion is motivated by the dual resonance model, where such a pattern arises naturally from the existence of a critical space-time dimension. This is easily confirmed in the model (and provides a simple test for what is the critical dimension) by considering the amplitudes for spinless particles. The results of pi N phase shift analysis are discussed to give a speculative phenomenological estimate of the appropriate higher symmetry. (16 refs).

  9. Dual Youla parameterization

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik

    2003-01-01

    A different aspect of using the parameterisation of all systems stabilised by a given controller, i.e. the dual Youla parameterisation, is considered. The relation between system change and the dual Youla parameter is derived in explicit form. A number of standard uncertain model descriptions...... are considered and the relation with the dual Youla parameter given. Some applications of the dual Youla parameterisation are considered in connection with the design of controllers and model/performance validation....

  10. Dual-permeability model for water flow and solute transport in shrinking soils

    Science.gov (United States)

    Coppola, Antonio; Gerke, Horst; Comegna, Alessandro; Basile, Angelo

    2014-05-01

    A dual-permeability approach was extended to describe preferential water flow and solute transport in shrinking soils. In the approach, the soil is treated as a dual-permeability bulk porous medium consisting of dynamic interacting matrix and fractures pore domains. Water flow and solute transport in both the domains are described by the Richards' equation and advection-dispersion equation, respectively. In the model the contributions of the two regions to water flow and solute transport is changed dynamically according to the shrinkage characteristic exhibited under soil drying. Aggregate deformation during wetting/drying cycles is assumed to change only the relative proportions of voids in the fractures and in the aggregates, while the total volume of pores (and thus the layer thickness) remains unchanged. Thus, the partial contributions of the fracture and aggregate domains, are now a function of the water content (or the pressure head h), while their sum, the bulk porosity, is assumed to be constant. Any change in the aggregate contribution to total porosity is directly converted into a proportional change in the fracture porosity. This means that bulk volume change during shrinkage is mainly determined by change in crack volume rather than by change in layer thickness. This simplified approach allows dealing with an expansive soil as with a macroscopically rigid soil. The model was already tested by investigating whether and how well hydraulic characteristics obtained under the assumption of "dynamic" dual-permeability hydraulic parameterizations, or, alternatively, assuming the rigidity of the porous medium, reproduced measured soil water contents in a shrinking soil. Here we will discuss theoretical implications of the model in terms of relative importance of the parameters involved. The relative importance will be evaluated for different flow and transport processes and for different initial and top boundary conditions. Key words: Preferential flow and

  11. Experimental Study and ANN Dual-Time Scale Perturbation Model of Electrokinetic Properties of Microbiota.

    Science.gov (United States)

    Liu, Yong; Munteanu, Cristian R; Fernandez-Lozano, Carlos; Pazos, Alejandro; Ran, Tao; Tan, Zhiliang; Yu, Yizun; Zhou, Chuanshe; Tang, Shaoxun; González-Díaz, Humberto

    2017-01-01

    The electrokinetic properties of the rumen microbiota are involved in cell surface adhesion and microbial metabolism. An in vitro study was carried out in batch culture to determine the effects of three levels of special surface area (SSA) of biomaterials and four levels of surface tension (ST) of culture medium on electrokinetic properties (Zeta potential, ξ; electrokinetic mobility, μ e ), fermentation parameters (volatile fatty acids, VFAs), and ST over fermentation processes (ST-a, γ). The obtained results were combined with previously published data (digestibility, D; pH; concentration of ammonia nitrogen, c(NH 3 -N)) to establish a predictive artificial neural network (ANN) model. Concepts of dual-time series analysis, perturbation theory (PT), and Box-Jenkins Operators were applied for the first time to develop an ANN model to predict the variations of the electrokinetic properties of microbiota. The best dual-time series Radial Basis Functions (RBR) model for ξ of rumen microbiota predicted ξ for >30,000 cases with a correlation coefficient >0.8. This model provided insight into the correlations between electrokinetic property (zeta potential) of rumen microbiota and the perturbations of physical factors (specific surface area and surface tension) of media, digestibility of substrate, and their metabolites (NH 3 -N, VFAs) in relation to environmental factors.

  12. Toward A Dual-Learning Systems Model of Speech Category Learning

    Directory of Open Access Journals (Sweden)

    Bharath eChandrasekaran

    2014-07-01

    Full Text Available More than two decades of work in vision posits the existence of dual-learning systems of category learning. The reflective system uses working memory to develop and test rules for classifying in an explicit fashion, while the reflexive system operates by implicitly associating perception with actions that lead to reinforcement. Dual-learning systems models hypothesize that in learning natural categories, learners initially use the reflective system and, with practice, transfer control to the reflexive system. The role of reflective and reflexive systems in auditory category learning and more specifically in speech category learning has not been systematically examined. In this article we describe a neurobiologically-constrained dual-learning systems theoretical framework that is currently being developed in speech category learning and review recent applications of this framework. Using behavioral and computational modeling approaches, we provide evidence that speech category learning is predominantly mediated by the reflexive learning system. In one application, we explore the effects of normal aging on non-speech and speech category learning. We find an age related deficit in reflective-optimal but not reflexive-optimal auditory category learning. Prominently, we find a large age-related deficit in speech learning. The computational modeling suggests that older adults are less likely to transition from simple, reflective, uni-dimensional rules to more complex, reflexive, multi-dimensional rules. In a second application we summarize a recent study examining auditory category learning in individuals with elevated depressive symptoms. We find a deficit in reflective-optimal and an enhancement in reflexive-optimal auditory category learning. Interestingly, individuals with elevated depressive symptoms also show an advantage in learning speech categories. We end with a brief summary and description of a number of future directions.

  13. Dual AAV Gene Therapy for Duchenne Muscular Dystrophy with a 7-kb Mini-Dystrophin Gene in the Canine Model.

    Science.gov (United States)

    Kodippili, Kasun; Hakim, Chady H; Pan, Xiufang; Yang, Hsiao T; Yue, Yongping; Zhang, Yadong; Shin, Jin-Hong; Yang, N Nora; Duan, Dongsheng

    2018-03-01

    Dual adeno-associated virus (AAV) technology was developed in 2000 to double the packaging capacity of the AAV vector. The proof of principle has been demonstrated in various mouse models. Yet, pivotal evidence is lacking in large animal models of human diseases. Here we report expression of a 7-kb canine ΔH2-R15 mini-dystrophin gene using a pair of dual AAV vectors in the canine model of Duchenne muscular dystrophy (DMD). The ΔH2-R15 minigene is by far the most potent synthetic dystrophin gene engineered for DMD gene therapy. We packaged minigene dual vectors in Y731F tyrosine-modified AAV-9 and delivered to the extensor carpi ulnaris muscle of a 12-month-old affected dog at the dose of 2 × 10 13 viral genome particles/vector/muscle. Widespread mini-dystrophin expression was observed 2 months after gene transfer. The missing dystrophin-associated glycoprotein complex was restored. Treatment also reduced muscle degeneration and fibrosis and improved myofiber size distribution. Importantly, dual AAV therapy greatly protected the muscle from eccentric contraction-induced force loss. Our data provide the first clear evidence that dual AAV therapy can be translated to a diseased large mammal. Further development of dual AAV technology may lead to effective therapies for DMD and many other diseases in human patients.

  14. Some isomorphic function and Fock space representations of the dual model superconformal group

    International Nuclear Information System (INIS)

    Horsley, R.

    1977-12-01

    The dual model superconformal group is first constructed as the set of transformations which preserve up to a variable factor a suitably defined metric in a superspace (Z, theta) where Z is (essentially) a complex number and theta is a Grassmann parameter. This means one has a graded Lie group. Superfunctions are then found which enable some super unitary representations to be constructed. This necessitates the introduction of enlarged matrices - some submatrices of which are composed of Grassmann elements. Finally isomorphic (up to a factor) Fock space representations are exhibited. (Auth.)

  15. High energy charge exchange np and antipp scattering using the dual fermion model

    International Nuclear Information System (INIS)

    Weigt, G.

    1976-01-01

    The five independent helicity amplitudes Phisub(i)(s, t) calculated by Mandelstam from the Neveu-Schwarz-Ramond model for fermion-antifermion scattering are used in the Regge limit for a phenomenological description of high energy np and antipp charge exchange scattering. A forward spike which widens with increasing energy as well as an energy dependence changing from lower to higher energy data are reproduced by these non-evasive dual Born amplitudes using π, A 2 and rho Regge pole t-channel exchanges. (author)

  16. Jacobi–Lie symmetry and Jacobi–Lie T-dual sigma models on group manifolds

    Directory of Open Access Journals (Sweden)

    A. Rezaei-Aghdam

    2018-01-01

    Full Text Available Using the concept of Jacobi–Lie group and Jacobi–Lie bialgebra, we generalize the definition of Poisson–Lie symmetry to Jacobi–Lie symmetry. In this regard, we generalize the concept of Poisson–Lie T-duality to Jacobi–Lie T-duality and present Jacobi–Lie T-dual sigma models on Lie groups, which have Jacobi–Lie symmetry. Using this symmetry, new cases of duality appear and some examples are given. This generalization may provide insights to understand the quantum features of Poisson–Lie T-duality, in a more satisfactory way.

  17. Dual energy CT at the synchrotron: A piglet model for neurovascular research

    Energy Technology Data Exchange (ETDEWEB)

    Schueltke, Elisabeth, E-mail: e.schultke@usask.ca [University of Saskatchewan, Saskatoon, SK (Canada); Kelly, Michael E. [University of Saskatchewan, Saskatoon, SK (Canada); Nemoz, Christian [European Synchrotron Radiation Facility (ESRF), 6 rue Horowitz, 38043 Grenoble (France); Fiedler, Stefan [European Molecular Biology Laboratory (EMBL), Nottkestrasse 85, 22603 Hamburg (Germany); Ogieglo, Lissa [University of Saskatchewan, Saskatoon, SK (Canada); Crawford, Paul [Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Herfordshire AL9 7TA (United Kingdom); Paterson, Jessica; Beavis, Cole [University of Saskatchewan, Saskatoon, SK (Canada); Esteve, Francois [CR INSERM U836-Team 6/ESRF, 6 rue Horowitz, 38043 Grenoble (France); Brochard, Thierry; Renier, Michel; Requardt, Herwig; Dallery, Dominique; Le Duc, Geraldine [European Synchrotron Radiation Facility (ESRF), 6 rue Horowitz, 38043 Grenoble (France); Meguro, Kotoo [University of Saskatchewan, Saskatoon, SK (Canada)

    2011-08-15

    Background: Although the quality of imaging techniques available for neurovascular angiography in the hospital environment has significantly improved over the last decades, the equipment used for clinical work is not always suited for neurovascular research in animal models. We have previously investigated the suitability of synchrotron-based K-edge digital subtraction angiography (KEDSA) after intravenous injection of iodinated contrast agent for neurovascular angiography in radiography mode in both rabbit and pig models. We now have used the KEDSA technique for the acquisition of three-dimensional images and dual energy CT. Materials and methods: All experiments were conducted at the biomedical beamline ID 17 of the European Synchrotron Radiation Facility (ESRF). A solid state germanium (Ge) detector was used for the acquisition of image pairs at 33.0 and 33.3 keV. Three-dimensional images were reconstructed from an image series containing 60 single images taken throughout a full rotation of 360{sup o}. CT images were reconstructed from two half-acquisitions with 720 projections each. Results: The small detector field of view was a limiting factor in our experiments. Nevertheless, we were able to show that dual energy CT using the KEDSA technique available at ID 17 is suitable for neurovascular research in animal models.

  18. The Similar Structure Method for Solving the Model of Fractal Dual-Porosity Reservoir

    Directory of Open Access Journals (Sweden)

    Li Xu

    2013-01-01

    Full Text Available This paper proposes a similar structure method (SSM to solve the boundary value problem of the extended modified Bessel equation. The method could efficiently solve a second-order linear homogeneous differential equation’s boundary value problem and obtain its solutions’ similar structure. A mathematics model is set up on the dual-porosity media, in which the influence of fractal dimension, spherical flow, wellbore storage, and skin factor is taken into cosideration. Researches in the model found that it was a special type of the extended modified Bessel equation in Laplace space. Then, the formation pressure and wellbore pressure under three types of outer boundaries (infinite, constant pressure, and closed are obtained via SSM in Laplace space. Combining SSM with the Stehfest algorithm, we propose the similar structure method algorithm (SSMA which can be used to calculate wellbore pressure and pressure derivative of reservoir seepage models clearly. Type curves of fractal dual-porosity spherical flow are plotted by SSMA. The presented algorithm promotes the development of well test analysis software.

  19. Dynamic Model and Fault Feature Research of Dual-Rotor System with Bearing Pedestal Looseness

    Directory of Open Access Journals (Sweden)

    Nanfei Wang

    2016-01-01

    Full Text Available The paper presents a finite element model of dual-rotor system with pedestal looseness stemming from loosened bolts. Dynamic model including bearing pedestal looseness is established based on the dual-rotor test rig. Three-degree-of-freedom (DOF planar rigid motion of loose bearing pedestal is fully considered and collision recovery coefficient is also introduced in the model. Based on the Timoshenko beam elements, using the finite element method, rigid body kinematics, and the Newmark-β algorithm for numerical simulation, dynamic characteristics of the inner and outer rotors and the bearing pedestal plane rigid body motion under bearing pedestal looseness condition are studied. Meanwhile, the looseness experiments under two different speed combinations are carried out, and the experimental results are basically the same. The simulation results are compared with the experimental results, indicating that vibration displacement waveforms of loosened rotor have “clipping” phenomenon. When the bearing pedestal looseness fault occurs, the inner and outer rotors vibration spectrum not only contains the difference and sum frequency of the two rotors’ fundamental frequency but also contains 2X and 3X component of rotor with loosened support, and so forth; low frequency spectrum is more, containing dividing component, and so forth; the rotor displacement spectrums also contain fewer combination frequency components, and so forth; when one side of the inner rotor bearing pedestal is loosened, the inner rotor axis trajectory is drawn into similar-ellipse shape.

  20. A dual-factor model of mental health: toward a more comprehensive understanding of youth functioning.

    Science.gov (United States)

    Antaramian, Susan P; Scott Huebner, E; Hills, Kimberly J; Valois, Robert F

    2010-10-01

    Traditional mental health models focus on psychological problems and distress; accordingly, health is viewed as the absence of illness or disability. In contrast, a dual-factor model of mental health incorporates both indicators of positive subjective well-being (SWB) and measures of psychopathological symptoms to comprehensively determine an individual's psychological adjustment. This study used such a dual-factor model to measure the mental health status of young adolescents. A total of 764 middle school students were classified into one of four distinct groups based on having high or low psychopathology and high or low SWB. Furthermore, group differences in student engagement, academic achievement, and environmental support for learning were investigated. Results demonstrated the existence of a traditionally neglected group of adolescents (low SWB and low psychopathology) who are nonetheless at risk for academic and behavior problems in school and who performed no better than the most troubled group of adolescents. Overall, both the presence of positive well-being and the absence of symptoms were necessary for ensuring the most advantageous school performance. These results highlight the importance of incorporating positive indicators of well-being along with traditional negative factors in more fully understanding relationships between individuals' mental health and educational outcomes. © 2010 American Orthopsychiatric Association.

  1. The dual model of perfectionism and depression among Chinese University students

    Directory of Open Access Journals (Sweden)

    Yefei Wang

    2017-02-01

    Full Text Available The dual model of perfectionism was adopted to explore the influence of adaptive and maladaptive perfectionism on depression in college students. The results support the dual process model of perfectionism in Chinese undergraduates. A sample of 206 Chinese undergraduates completed measures of perfectionism, General Self-efficacy Measure, Beck Depression Inventory, State Anxiety Inventory, Positive and Negative Affect Scale (Time 1 and Beck Depression Inventory 4 months later (Time 2. Exploratory and confirmatory factor analysis revealed that the three-factor model of perfectionism with dimensions of maladaptive perfectionism, adaptive perfectionism and order factor fit the date well. Partial correlations analyses revealed that maladaptive perfectionism was related to psychopathology, whereas adaptive perfectionism was more closely correlated with positive features of mental health. In cross-sectional analyses, the discrepancy which measures the perceived difference between the standards one has set for one’s own behaviour and actual performance and the socially prescribed perfectionism subscales of maladaptive perfectionism could significantly predict baseline depressive symptoms. However, after controlling for the initial scores of depression, none of the perfectionism subscales significantly predicted the change in depression across a 4-month lag. Distinguishing adaptive and maladaptive aspects of perfectionism may be beneficial to understanding the influence of perfectionism on depression.

  2. Hydroclimatology of Dual-Peak Annual Cholera Incidence: Insights from a Spatially Explicit Model

    Science.gov (United States)

    Bertuzzo, E.; Mari, L.; Righetto, L.; Gatto, M.; Casagrandi, R.; Rodriguez-Iturbe, I.; Rinaldo, A.

    2012-12-01

    Cholera incidence in some regions of the Indian subcontinent may exhibit two annual peaks although the main environmental drivers that have been linked to the disease (e.g. sea surface temperature, zooplankton abundance, river discharge) peak once per year during the summer. An empirical hydroclimatological explanation relating cholera transmission to river flows and to the disease spatial spreading has been recently proposed. We specifically support and substantiate mechanistically such hypothesis by means of a spatially explicit model of cholera transmission. Our framework directly accounts for the role of the river network in transporting and redistributing cholera bacteria among human communities as well as for spatial and temporal annual fluctuations of precipitation and river flows. To single out the single out the hydroclimatologic controls on the prevalence patterns in a non-specific geographical context, we first apply the model to Optimal Channel Networks as a general model of hydrological networks. Moreover, we impose a uniform distribution of population. The model is forced by seasonal environmental drivers, namely precipitation, temperature and chlorophyll concentration in the coastal environment, a proxy for Vibrio cholerae concentration. Our results show that these drivers may suffice to generate dual-peak cholera prevalence patterns for proper combinations of timescales involved in pathogen transport, hydrologic variability and disease unfolding. The model explains the possible occurrence of spatial patterns of cholera incidence characterized by a spring peak confined to coastal areas and a fall peak involving inland regions. We then proceed applying the model to the specific settings of Bay of Bengal accounting for the actual river networks (derived from digital terrain map manipulations), the proper distribution of population (estimated from downscaling of census data based on remotely sensed features) and precipitation patterns. Overall our

  3. Mueller-matrix modeling and characterization of a dual-crystal electro-optic modulator.

    Science.gov (United States)

    Cervantes-L, Joel; Serrano-Garcia, David I; Otani, Yukitoshi; Cense, Barry

    2016-10-17

    A general mathematical model based on Mueller-matrix calculation is presented to describe the optical behavior of a dual-crystal electro-optic modulator. The two crystals inside the modulator are oriented at ± 45° with respect to the horizontal, thereby cancelling natural birefringence and temperature-induced birefringence. We describe the behavior of the modulator as a function of the ellipticity of the crystals, the rotation angles of the crystals and the applied voltage. By fitting the measured data with a Mueller-matrix model that uses values for the ellipticity and orientation angles of the crystals, the simulated data and the experimental measurements could be matched. This Mueller-matrix includes physical properties of the thermally compensated electro optic modulator, and the matrix can be used in simulations where these device-specific properties are important, for instance in the modeling of a polarization-sensitive optical coherence tomography system.

  4. Complexity analysis of dual-channel game model with different managers' business objectives

    Science.gov (United States)

    Li, Ting; Ma, Junhai

    2015-01-01

    This paper considers dual-channel game model with bounded rationality, using the theory of bifurcations of dynamical system. The business objectives of retailers are assumed to be different, which is closer to reality than previous studies. We study the local stable region of Nash equilibrium point and find that business objectives can expand the stable region and play an important role in price strategy. One interesting finding is that a fiercer competition tends to stabilize the Nash equilibrium. Simulation shows the complex behavior of two dimensional dynamic system, we find period doubling bifurcation and chaos phenomenon. We measure performances of the model in different period by using the index of average profit. The results show that unstable behavior in economic system is often an unfavorable outcome. So this paper discusses the application of adaptive adjustment mechanism when the model exhibits chaotic behavior and then allows the retailers to eliminate the negative effects.

  5. Ligand-based modeling of Akt3 lead to potent dual Akt1/Akt3 inhibitor.

    Science.gov (United States)

    Al-Sha'er, Mahmoud A; Taha, Mutasem O

    2018-02-13

    Akt1 and Akt3 are important serine/threonine-specific protein kinases involved in G2 phase required by cancer cells to maintain cell cycle and to prevent cell death. Accordingly, inhibitors of these kinases should have potent anti-cancer properties. This prompted us to use pharmacophore/QSAR modeling to identify optimal binding models and physicochemical descriptors that explain bioactivity variation within a set of 74 diverse Akt3 inhibitors. Two successful orthogonal pharmacophores were identified and further validated using receiver operating characteristic (ROC) curve analyses. The pharmacophoric models and associated QSAR equation were applied to screen the national cancer institute (NCI) list of compounds for new Akt3 inhibitors. Six hits showed significant experimental anti-Akt3 IC 50 values, out of which one compound exhibited dual low micromolar anti-Akt1 and anti-Akt3 inhibitory profiles. Copyright © 2018 Elsevier Inc. All rights reserved.

  6. Data Analytics Based Dual-Optimized Adaptive Model Predictive Control for the Power Plant Boiler

    Directory of Open Access Journals (Sweden)

    Zhenhao Tang

    2017-01-01

    Full Text Available To control the furnace temperature of a power plant boiler precisely, a dual-optimized adaptive model predictive control (DoAMPC method is designed based on the data analytics. In the proposed DoAMPC, an accurate predictive model is constructed adaptively by the hybrid algorithm of the least squares support vector machine and differential evolution method. Then, an optimization problem is constructed based on the predictive model and many constraint conditions. To control the boiler furnace temperature, the differential evolution method is utilized to decide the control variables by solving the optimization problem. The proposed method can adapt to the time-varying situation by updating the sample data. The experimental results based on practical data illustrate that the DoAMPC can control the boiler furnace temperature with errors of less than 1.5% which can meet the requirements of the real production process.

  7. Acting in solidarity: Testing an extended dual pathway model of collective action by bystander group members.

    Science.gov (United States)

    Saab, Rim; Tausch, Nicole; Spears, Russell; Cheung, Wing-Yee

    2015-09-01

    We examined predictors of collective action among bystander group members in solidarity with a disadvantaged group by extending the dual pathway model of collective action, which proposes one efficacy-based and one emotion-based path to collective action (Van Zomeren, Spears, Fischer, & Leach, 2004). Based on two proposed functions of social identity performance (Klein, Spears, & Reicher, 2007), we distinguished between the efficacy of collective action at consolidating the identity of a protest movement and its efficacy at achieving social change (political efficacy). We expected identity consolidation efficacy to positively predict collective action tendencies directly and indirectly via political efficacy. We also expected collective action tendencies to be positively predicted by moral outrage and by sympathy in response to disadvantaged outgroup's suffering. These hypotheses were supported in two surveys examining intentions to protest for Palestine in Britain (Study 1), and intentions to attend the June 4th vigil in Hong Kong to commemorate the Tiananmen massacre among a sample of Hong Kong citizens (Study 2). The contributions of these findings to research on the dual pathway model of collective action and the different functions of collective action are discussed. © 2014 The British Psychological Society.

  8. A Dual Chamber Stent Prevents Organ Malperfusion in a Model of Donation after Cardiac Death

    Science.gov (United States)

    Tillman, Bryan W.; Chun, Youngjae; Cho, Sung Kwon; Chen, Yanfei; Liang, Nathan; Maul, Timothy; Demetris, Anthony; Gu, Xinzhu; Wagner, William R.; Tevar, Amit D.

    2016-01-01

    Background The paradigm for Donation after Cardiac Death (DCD) subjects donor organs to significant ischemic injury. A dual-chamber Organ Perfusion Stent (OPS) would maintain organ perfusion without impacting natural cardiac death. A center lumen allows uninterrupted cardiac blood flow, while an external chamber delivers oxygenated blood to the visceral vessels. Methods A prototype OPS was constructed from commercial stents. In a porcine model, the OPS was deployed, followed by a simulated agonal period. Oxygenated blood perfused the external stent chamber. Organ perfusion was compared between controls (n=3) and OPS (n=6). Finally, a custom nitinol dual chamber OPS was fabricated using a retrievable “petal and stem” design. Results Endovascular OPS deployment achieved visceral isolation without adverse impact on cardiac parameters. Visceral oxygen delivery was 4.8 fold higher as compared to controls. During the agonal period, organs in OPS treated animals appeared well perfused, contrasting to malperfused controls. A custom nitinol and polyurethane OPS was easily recaptured with simple sheath advancement. Conclusions An OPS maintained organ perfusion during the agonal phase in a model of DCD organ donation without adversely impacting cardiac function. Ultimately, the custom retrievable design of this study may help resolve the critical shortage of donor organs for transplant. PMID:27524434

  9. Dual chamber stent prevents organ malperfusion in a model of donation after cardiac death.

    Science.gov (United States)

    Tillman, Bryan W; Chun, Youngjae; Cho, Sung Kwon; Chen, Yanfei; Liang, Nathan; Maul, Timothy; Demetris, Anthony; Gu, Xinzhu; Wagner, William R; Tevar, Amit D

    2016-10-01

    The paradigm for donation after cardiac death subjects donor organs to ischemic injury. A dual-chamber organ perfusion stent would maintain organ perfusion without affecting natural cardiac death. A center lumen allows uninterrupted cardiac blood flow, while an external chamber delivers oxygenated blood to the visceral vessels. A prototype organ perfusion stent was constructed from commercial stents. In a porcine model, the organ perfusion stent was deployed, followed by a simulated agonal period. Oxygenated blood perfused the external stent chamber. Organ perfusion was compared between controls (n = 3) and organ perfusion stent (n = 6). Finally, a custom, nitinol, dual chamber organ perfusion stent was fabricated using a retrievable "petal and stem" design. Endovascular organ perfusion stent deployment achieved visceral isolation without adverse impact on cardiac parameters. Visceral oxygen delivery was 4.8-fold greater compared with controls. During the agonal period, organs in organ perfusion stent-treated animals appeared well perfused in contrast with the malperfused controls. A custom nitinol and polyurethane organ perfusion stent was recaptured easily with simple sheath advancement. An organ perfusion stent maintained organ perfusion during the agonal phase in a porcine model of donation after cardiac death organ donation without adversely affecting cardiac function. Ultimately, the custom retrievable design of this study may help resolve the critical shortage of donor organs for transplant. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Accounting for rainfall evaporation using dual-polarization radar and mesoscale model data

    Science.gov (United States)

    Pallardy, Quinn; Fox, Neil I.

    2018-02-01

    Implementation of dual-polarization radar should allow for improvements in quantitative precipitation estimates due to dual-polarization capability allowing for the retrieval of the second moment of the gamma drop size distribution. Knowledge of the shape of the DSD can then be used in combination with mesoscale model data to estimate the motion and evaporation of each size of drop falling from the height at which precipitation is observed by the radar to the surface. Using data from Central Missouri at a range between 130 and 140 km from the operational National Weather Service radar a rain drop tracing scheme was developed to account for the effects of evaporation, where individual raindrops hitting the ground were traced to the point in space and time where they interacted with the radar beam. The results indicated evaporation played a significant role in radar rainfall estimation in situations where the atmosphere was relatively dry. Improvements in radar estimated rainfall were also found in these situations by accounting for evaporation. The conclusion was made that the effects of raindrop evaporation were significant enough to warrant further research into the inclusion high resolution model data in the radar rainfall estimation process for appropriate locations.

  11. Pretreatment chemistry for dual media filtration: model simulations and experimental studies.

    Science.gov (United States)

    Shin, J Y; O'Melia, C R

    2006-01-01

    Laboratory dual media filtration experiments were conducted (a) in direct filtration mode using model raw water moderate in turbidity and low in DOC, and (b) in conventional filtration mode treating water moderate in turbidity and high in DOC. Model simulations of filter performance for the removal of particles provided hypotheses for the experimental studies of dual media filtration. An increase in alum dose in direct filtration mode, while improving filter performance, also showed some disadvantages, including rapid development of head loss. Suboptimal dose in direct filtration significantly impaired the filter performance. In conventional mode, the effect of alum dose on the filter performance, while obvious, was not as dramatic as in direct filtration. Ripening indicated by particle counts occurred earlier than by turbidity and breakthrough of particle counts started earlier than breakthrough of turbidity, suggesting that turbidity can be used as a more conservative monitor of filter performance during the ripening period to minimise the risk of passage of small particles, while particle counts can be considered a more sensitive indicator of deteriorating filter performance during the breakthrough period. The lower sand layer served as a multiple barrier for particle when the performance of the anthracite layer was not effective.

  12. An analytical model for cumulative infiltration into a dual-permeability media

    Science.gov (United States)

    Peyrard, Xavier; Lassabatere, Laurent; Angulo-Jaramillo, Rafael; Simunek, Jiri

    2010-05-01

    Modeling of water infiltration into the vadose zone is important for better understanding of movement of water-transported contaminants. There is a great need to take into account the soil heterogeneity and, in particular, the presence of macropores or cracks that could generate preferential flow. Several mathematical models have been proposed to describe unsaturated flow through heterogeneous soils. The dual-permeability model assumes that flow is governed by Richards equation in both porous regions (matrix and fractures). Water can be exchanged between the two regions following a first-order rate law. A previous study showed that the influence of the hydraulic conductivity of the matrix/macropore interface had a little influence on cumulative infiltration at the soil surface. As a result, one could consider the surface infiltration for a specific case of no water exchange between the fracture and matrix regions (a case of zero interfacial hydraulic conductivity). In such a case, water infiltration can be considered to be the sum of the cumulative infiltrations into the matrix and the fractures. On the basis of analytical models for each sub domain (matrix and fractures), an analytical model is proposed for the entire dual-porosity system. A sensitivity analysis is performed to characterize the influence of several factors, such as the saturated hydraulic conductivity ratio, the water pressure scale parameter ratio, and the saturated volumetric water content scale ratio, on the total cumulative infiltration. Such an analysis greatly helps in quantifying the impact of macroporosity and fractures on water infiltration, which can be of great interest for hydrological models.

  13. New normative standards of conditional reasoning and the dual-source model.

    Science.gov (United States)

    Singmann, Henrik; Klauer, Karl Christoph; Over, David

    2014-01-01

    There has been a major shift in research on human reasoning toward Bayesian and probabilistic approaches, which has been called a new paradigm. The new paradigm sees most everyday and scientific reasoning as taking place in a context of uncertainty, and inference is from uncertain beliefs and not from arbitrary assumptions. In this manuscript we present an empirical test of normative standards in the new paradigm using a novel probabilized conditional reasoning task. Our results indicated that for everyday conditional with at least a weak causal connection between antecedent and consequent only the conditional probability of the consequent given antecedent contributes unique variance to predicting the probability of conditional, but not the probability of the conjunction, nor the probability of the material conditional. Regarding normative accounts of reasoning, we found significant evidence that participants' responses were confidence preserving (i.e., p-valid in the sense of Adams, 1998) for MP inferences, but not for MT inferences. Additionally, only for MP inferences and to a lesser degree for DA inferences did the rate of responses inside the coherence intervals defined by mental probability logic (Pfeifer and Kleiter, 2005, 2010) exceed chance levels. In contrast to the normative accounts, the dual-source model (Klauer et al., 2010) is a descriptive model. It posits that participants integrate their background knowledge (i.e., the type of information primary to the normative approaches) and their subjective probability that a conclusion is seen as warranted based on its logical form. Model fits showed that the dual-source model, which employed participants' responses to a deductive task with abstract contents to estimate the form-based component, provided as good an account of the data as a model that solely used data from the probabilized conditional reasoning task.

  14. A Dual Regime Reactive Transport Model for Simulation of High Level Waste Tank Closure Scenarios - 13375

    International Nuclear Information System (INIS)

    Sarkar, Sohini; Kosson, David S.; Brown, Kevin; Garrabrants, Andrew C.; Meeussen, Hans; Van der Sloot, Hans

    2013-01-01

    A numerical simulation framework is presented in this paper for estimating evolution of pH and release of major species from grout within high-level waste tanks after closure. This model was developed as part of the Cementitious Barriers Partnership. The reactive transport model consists of two parts - (1) transport of species, and (2) chemical reactions. The closure grout can be assumed to have varying extents of cracking and composition for performance assessment purposes. The partially or completely degraded grouted tank is idealized as a dual regime system comprising of a mobile region having solid materials with cracks and macro-pores, and an immobile/stagnant region having solid matrix with micropores. The transport profiles of the species are calculated by incorporating advection of species through the mobile region, diffusion of species through the immobile/stagnant region, and exchange of species between the mobile and immobile regions. A geochemical speciation code in conjunction with the pH dependent test data for a grout material is used to obtain a mineral set that best describes the trends in the test data of the major species. The dual regime reactive transport model predictions are compared with the release data from an up-flow column percolation test. The coupled model is then used to assess effects of crack state of the structure, rate and composition of the infiltrating water on the pH evolution at the grout-waste interface. The coupled reactive transport model developed in this work can be used as part of the performance assessment process for evaluating potential risks from leaching of a cracked tank containing elements of human health and environmental concern. (authors)

  15. Analyses of Spring Barley Evapotranspiration Rates Based on Gradient Measurements and Dual Crop Coefficient Model

    Directory of Open Access Journals (Sweden)

    Gabriela Pozníková

    2014-01-01

    Full Text Available The yield of agricultural crops depends on water availability to a great extent. According some projections, the likelihood of stress caused by drought is increasing in future climates expected for the Central Europe. Therefore, in order to manage agro-ecosystems properly, it is necessary to know water demand of particular crops as precisely as possible. Evapotranspiration (ET is the main part of water balance which takes the water from agro-ecosystems away. The ET consists of evaporation from the soil (E and transpiration (T through the stomata of plants. In this study, we investigated ET of spring barley 1-ha field (Domanínek, Czech Republic measured by Bowen ratio/energy balance method during growing period 2013 (May 8 to July 31. Special focus was dedicated to comparison of barley ET with the reference grass ETo calculated according FAO-56 model, i.e. the determination of barley crop coefficient (Kc. This crop coefficient was subsequently separated into soil evaporation (Ke and transpiration fraction (Kcb by adjusting soil and phenological parameters of dual crop coefficient model to minimize the root mean square error between measured and modelled ET. The resulting Kcb of barley was 0.98 during mid-growing period and 0.05 during initial and end periods. According to FAO-56, typical values are 1.10 and 0.15 for Kcb mid and Kcb end, respectively. Modelled and measured ET show satisfactory agreement with root mean square error equal 0.41 mm. Based on the sums of ET and E for the whole growing season of the spring barley, ET partitioning by FAO-56 dual crop coefficient model resulted in E/ET ratio being 0.24.

  16. Inverse modeling of multicomponent reactive transport through single and dual porosity media

    Science.gov (United States)

    Samper, Javier; Zheng, Liange; Fernández, Ana María; Montenegro, Luis

    2008-06-01

    Compacted bentonite is foreseen as buffer material for high-level radioactive waste in deep geological repositories because it provides hydraulic isolation, chemical stability, and radionuclide sorption. A wide range of laboratory tests were performed within the framework of FEBEX ( Full-scale Engineered Barrier EXperiment) project to characterize buffer properties and develop numerical models for FEBEX bentonite. Here we present inverse single and dual-continuum multicomponent reactive transport models of a long-term permeation test performed on a 2.5 cm long sample of FEBEX bentonite. Initial saline bentonite porewater was flushed with 5.5 pore volumes of fresh granitic water. Water flux and chemical composition of effluent waters were monitored during almost 4 years. The model accounts for solute advection and diffusion and geochemical reactions such as aqueous complexation, acid-base, cation exchange, protonation/deprotonation by surface complexation and dissolution/precipitation of calcite, chalcedony and gypsum. All of these processes are assumed at local equilibrium. Similar to previous studies of bentonite porewater chemistry on batch systems which attest the relevance of protonation/deprotonation on buffering pH, our results confirm that protonation/deprotonation is a key process in maintaining a stable pH under dynamic transport conditions. Breakthrough curves of reactive species are more sensitive to initial porewater concentration than to effective diffusion coefficient. Optimum estimates of initial porewater chemistry of saturated compacted FEBEX bentonite are obtained by solving the inverse problem of multicomponent reactive transport. While the single-continuum model reproduces the trends of measured data for most chemical species, it fails to match properly the long tails of most breakthrough curves. Such limitation is overcome by resorting to a dual-continuum reactive transport model.

  17. New Normative Standards of Conditional Reasoning and the Dual-Source Model

    Directory of Open Access Journals (Sweden)

    Henrik eSingmann

    2014-04-01

    Full Text Available There has been a major shift in research on human reasoning towards Bayesian and probabilistic approaches, which has been called a new paradigm. The new paradigm sees most everyday and scientific reasoning as taking place in a context of uncertainty, and inference is from uncertain beliefs and not from arbitrary assumptions. In this manuscript we present an empirical test of normative standards in the new paradigm using a novel probabilized conditional reasoning task. Our results indicated that for everyday conditional with at least a weak causal connection between antecedent and consequent only the conditional probability of the consequent given antecedent contributes unique variance to predicting the probability of conditional, but not the probability of the conjunction, nor the probability of the material conditional. Regarding normative accounts of reasoning, we found significant evidence that participants' responses were confidence preserving (i.e., p-valid in the sense of Adams, 1998 for MP inferences, but not for MT inferences. Additionally, only for MP inferences and to a lesser degree for DA inferences did the rate of responses inside the coherence intervals defined by mental probability logic (Pfeifer & Kleiter, 2005, 2010 exceed chance levels. In contrast to the normative accounts, the dual-source model (Klauer, Beller, & Hütter, 2010 is a descriptive model. It posits that participants integrate their background knowledge (i.e., the type of information primary to the normative approaches and their subjective probability that a conclusion is seen as warranted based on its logical form. Model fits showed that the dual-source model, which employed participants' responses to a deductive task with abstract contents to estimate the form-based component, provided as good an account of the data as a model that solely used data from the probabilized conditional reasoning task.

  18. Detecting Intracranial Hemorrhage Using Automatic Tube Current Modulation With Advanced Modeled Iterative Reconstruction in Unenhanced Head Single- and Dual-Energy Dual-Source CT.

    Science.gov (United States)

    Scholtz, Jan-Erik; Wichmann, Julian L; Bennett, Dennis W; Leithner, Doris; Bauer, Ralf W; Vogl, Thomas J; Bodelle, Boris

    2017-05-01

    The purpose of our study was to determine diagnostic accuracy, image quality, and radiation dose of low-dose single- and dual-energy unenhanced third-generation dual-source head CT for detection of intracranial hemorrhage (ICH). A total of 123 patients with suspected ICH were examined using a dual-source 192-MDCT scanner. Standard-dose 120-kVp single-energy CT (SECT; n = 36) and 80-kVp and 150-kVp dual-energy CT (DECT; n = 30) images were compared with low-dose SECT (n = 32) and DECT (n = 25) images obtained using automated tube current modulation (ATCM). Advanced modeled iterative reconstruction (ADMIRE) was used for all protocols. Detection of ICH was performed by three readers who were blinded to the image acquisition parameters of each image series. Image quality was assessed both quantitatively and qualitatively. Interobserver agreement was calculated using the Fleiss kappa. Radiation dose was measured as dose-length product (DLP). Detection of ICH was excellent (sensitivity, 94.9-100%; specificity, 94.7-100%) in all protocols (p = 1.00) with perfect interobserver agreement (0.83-0.96). Qualitative ratings showed significantly better ratings for both standard-dose protocols regarding gray matter-to-white matter contrast (p ≤ 0.014), whereas highest gray matter-to-white matter contrast-to-noise ratio was observed with low-dose DECT images (p ≥ 0.057). The lowest posterior fossa artifact index was measured for standard-dose DECT, which showed significantly lower values compared with low-dose protocols (p ≤ 0.034). Delineation of ventricular margins and sharpness of subarachnoidal spaces were rated excellent in all protocols (p ≥ 0.096). Low-dose techniques lowered radiation dose by 26% for SECT images (DLP, 575.0 ± 72.3 mGy · cm vs 771.5 ± 146.8 mGy · cm; p dual-source CT while allowing significant radiation dose reduction.

  19. A Riccati Based Homogeneous and Self-Dual Interior-Point Method for Linear Economic Model Predictive Control

    DEFF Research Database (Denmark)

    Sokoler, Leo Emil; Frison, Gianluca; Edlund, Kristian

    2013-01-01

    In this paper, we develop an efficient interior-point method (IPM) for the linear programs arising in economic model predictive control of linear systems. The novelty of our algorithm is that it combines a homogeneous and self-dual model, and a specialized Riccati iteration procedure. We test...

  20. A Simplified Micromechanical Modeling Approach to Predict the Tensile Flow Curve Behavior of Dual-Phase Steels

    Science.gov (United States)

    Nanda, Tarun; Kumar, B. Ravi; Singh, Vishal

    2017-11-01

    Micromechanical modeling is used to predict material's tensile flow curve behavior based on microstructural characteristics. This research develops a simplified micromechanical modeling approach for predicting flow curve behavior of dual-phase steels. The existing literature reports on two broad approaches for determining tensile flow curve of these steels. The modeling approach developed in this work attempts to overcome specific limitations of the existing two approaches. This approach combines dislocation-based strain-hardening method with rule of mixtures. In the first step of modeling, `dislocation-based strain-hardening method' was employed to predict tensile behavior of individual phases of ferrite and martensite. In the second step, the individual flow curves were combined using `rule of mixtures,' to obtain the composite dual-phase flow behavior. To check accuracy of proposed model, four distinct dual-phase microstructures comprising of different ferrite grain size, martensite fraction, and carbon content in martensite were processed by annealing experiments. The true stress-strain curves for various microstructures were predicted with the newly developed micromechanical model. The results of micromechanical model matched closely with those of actual tensile tests. Thus, this micromechanical modeling approach can be used to predict and optimize the tensile flow behavior of dual-phase steels.

  1. Activation and Binding in Verbal Working Memory: A Dual-Process Model for the Recognition of Nonwords

    Science.gov (United States)

    Oberauer, Klauss; Lange, Elke B.

    2009-01-01

    The article presents a mathematical model of short-term recognition based on dual-process models and the three-component theory of working memory [Oberauer, K. (2002). Access to information in working memory: Exploring the focus of attention. "Journal of Experimental Psychology: Learning, Memory, and Cognition, 28", 411-421]. Familiarity arises…

  2. Strangeness production in hadronic and nuclear collisions in the dual parton model

    International Nuclear Information System (INIS)

    Capella, A.; Tran Thanh Van, J.; Ranft, J.

    1993-01-01

    Λ, antiΛ and K s 0 production is studied in a Monte Carlo Dual Parton model for hadron-hadron, hadron-nucleus and nucleus-nucleus collisions with a SU(3) symmetric sea for chain formation (chain ends) but strangeness suppression in the chain fragmentation. Additionally, (qq)-(antiqantiq) production from the sea was introduced into the chain formation process with the same probability as for the q → qq branching within the chain decay process. This together with the popcorn mechanism of diquark fragmentation result in a new central component of hyperon production, which was not present in previous versions of the model. With these assumptions rapidity distributions and multiplicity ratios for strange particles in hadron-hadron, hadron-nucleus and nucleus-nucleus collisions are compared to a comprehensive collection of experimental data. 5 figs., 2 tabs., 15 refs

  3. Research on the Complexity of Dual-Channel Supply Chain Model in Competitive Retailing Service Market

    Science.gov (United States)

    Ma, Junhai; Li, Ting; Ren, Wenbo

    2017-06-01

    This paper examines the optimal decisions of dual-channel game model considering the inputs of retailing service. We analyze how adjustment speed of service inputs affect the system complexity and market performance, and explore the stability of the equilibrium points by parameter basin diagrams. And chaos control is realized by variable feedback method. The numerical simulation shows that complex behavior would trigger the system to become unstable, such as double period bifurcation and chaos. We measure the performances of the model in different periods by analyzing the variation of average profit index. The theoretical results show that the percentage share of the demand and cross-service coefficients have important influence on the stability of the system and its feasible basin of attraction.

  4. A stochastic inventory management model for a dual sourcing supply chain with disruptions

    Science.gov (United States)

    Iakovou, Eleftherios; Vlachos, Dimitrios; Xanthopoulos, Anastasios

    2010-03-01

    As companies continue to globalise their operations and outsource significant portion of their value chain activities, they often end up relying heavily on order replenishments from distant suppliers. The explosion in long-distance sourcing is exposing supply chains and shareholder value at ever increasing operational and disruption risks. It is well established, both in academia and in real-world business environments, that resource flexibility is an effective method for hedging against supply chain disruption risks. In this contextual framework, we propose a single period stochastic inventory decision-making model that could be employed for capturing the trade-off between inventory policies and disruption risks for an unreliable dual sourcing supply network for both the capacitated and uncapacitated cases. Through the developed model, we obtain some important managerial insights and evaluate the merit of contingency strategies in managing uncertain supply chains.

  5. Three-Dimensional Electromagnetic Mixing Models for Dual-Phase Steel Microstructures

    Directory of Open Access Journals (Sweden)

    Weibin Zhou

    2018-03-01

    Full Text Available Linking the ferrite fraction in a dual-phase (DP steel microstructure and its electromagnetic properties is critical in the effort to develop on-line measurement techniques for phase transformation using electromagnetic (EM sensors. This paper developed a seamlessly integrated method for generating 3D microstructures and evaluating their equivalent permeability values. Both the generation of 3D microstructures and evaluation of equivalent permeability have been achieved through custom modelling packages developed by the authors. Voronoi modelling based on the random close packing of spheres (RCPS-VM was used to precisely control the ferrite fraction in DP steel microstructure, and an equivalent uniform field method for 3D finite element simulation was developed for efficient analysis.

  6. Advantages of a dual-tracer model over reference tissue models for binding potential measurement in tumors

    Science.gov (United States)

    Tichauer, K M; Samkoe, K S; Klubben, W S; Hasan, T; Pogue, B W

    2012-01-01

    The quantification of tumor molecular expression in vivo could have a significant impact for informing and monitoring immerging targeted therapies in oncology. Molecular imaging of targeted tracers can be used to quantify receptor expression in the form of a binding potential (BP) if the arterial input curve or a surrogate of it is also measured. However, the assumptions of the most common approaches (reference tissue models) may not be valid for use in tumors. In this study, the validity of reference tissue models is investigated for use in tumors experimentally and in simulations. Three different tumor lines were grown subcutaneously in athymic mice and the mice were injected with a mixture of an epidermal growth factor receptor- (EGFR-) targeted fluorescent tracer and an untargeted fluorescent tracer. A one-compartment plasma input model demonstrated that the transport kinetics of both tracers were significantly different between tumors and all potential reference tissues, and using the reference tissue model resulted in a theoretical underestimation in BP of 50 ± 37%. On the other hand, the targeted and untargeted tracers demonstrated similar transport kinetics, allowing a dual-tracer approach to be employed to accurately estimate binding potential (with a theoretical error of 0.23 ± 9.07%). These findings highlight the potential for using a dual-tracer approach to quantify receptor expression in tumors with abnormal hemodynamics, possibly to inform the choice or progress of molecular cancer therapies. PMID:23022732

  7. Optimization of dual-wavelength intravascular photoacoustic imaging of atherosclerotic plaques using Monte Carlo optical modeling

    Science.gov (United States)

    Dana, Nicholas; Sowers, Timothy; Karpiouk, Andrei; Vanderlaan, Donald; Emelianov, Stanislav

    2017-10-01

    Coronary heart disease (the presence of coronary atherosclerotic plaques) is a significant health problem in the industrialized world. A clinical method to accurately visualize and characterize atherosclerotic plaques is needed. Intravascular photoacoustic (IVPA) imaging is being developed to fill this role, but questions remain regarding optimal imaging wavelengths. We utilized a Monte Carlo optical model to simulate IVPA excitation in coronary tissues, identifying optimal wavelengths for plaque characterization. Near-infrared wavelengths (≤1800 nm) were simulated, and single- and dual-wavelength data were analyzed for accuracy of plaque characterization. Results indicate light penetration is best in the range of 1050 to 1370 nm, where 5% residual fluence can be achieved at clinically relevant depths of ≥2 mm in arteries. Across the arterial wall, fluence may vary by over 10-fold, confounding plaque characterization. For single-wavelength results, plaque segmentation accuracy peaked at 1210 and 1720 nm, though correlation was poor (primary wavelength (≈1.0). Results suggest that, without flushing the luminal blood, a primary and secondary wavelength near 1210 and 1350 nm, respectively, may offer the best implementation of dual-wavelength IVPA imaging. These findings could guide the development of a cost-effective clinical system by highlighting optimal wavelengths and improving plaque characterization.

  8. Impact of Antenna Correlation on a New Dual-Hop MIMO AF Relaying Model

    Directory of Open Access Journals (Sweden)

    Amarasuriya Gayan

    2010-01-01

    Full Text Available A novel system model is proposed for the dual-hop multiple-input multiple-output amplify-andforward relay networks, and the impact of antenna correlation on the performance is studied. For a semiarbitrary correlated source-relay channel and an arbitrary correlated relay-destination channel, the complementary cumulative distribution function (CCDF and the moment-generating function (MGF approximations of the end-to-end signal-to-noise ratio (SNR are derived. The outage probability, the average symbol error rate (SER, and the ergodic capacity approximations are also derived. Two special cases are treated explicitly: (1 dual-antenna relay and multiple-antenna destination and (2 uncorrelated antennas at the relay and correlated antennas at the destination. For the first case, the CCDF, the MGF and the average SER of an upper bound of the end-to-end SNR are derived in closed-form. For the second case, the CCDF, the MGF, the average SER, and the moments of SNR are derived in closed-form; as well, the high SNR approximations for the outage probability and the average SER are derived, and the diversity gain and coding gain are developed. Extensive numerical results and Monte Carlo simulation results are presented to verify the analytical results and to quantify the detrimental impact of antenna correlations on the system performance.

  9. CT/FMT dual-model imaging of breast cancer based on peptide-lipid nanoparticles

    Science.gov (United States)

    Xu, Guoqiang; Lin, Qiaoya; Lian, Lichao; Qian, Yuan; Lu, Lisen; Zhang, Zhihong

    2016-03-01

    Breast cancer is one of the most harmful cancers in human. Its early diagnosis is expected to improve the patients' survival rate. X-ray computed tomography (CT) has been widely used in tumor detection for obtaining three-dimentional information. Fluorescence Molecular Tomography (FMT) imaging combined with near-infrared fluorescent dyes provides a powerful tool for the acquisition of molecular biodistribution information in deep tissues. Thus, the combination of CT and FMT imaging modalities allows us to better differentiate diseased tissues from normal tissues. Here we developed a tumor-targeting nanoparticle for dual-modality imaging based on a biocompatible HDL-mimicking peptide-phospholipid scaffold (HPPS) nanocarrier. By incorporation of CT contrast agents (iodinated oil) and far-infrared fluorescent dyes (DiR-BOA) into the hydrophobic core of HPPS, we obtained the FMT and CT signals simultaneously. Increased accumulation of the nanoparticles in the tumor lesions was achieved through the effect of the tumor-targeting peptide on the surface of nanoparticle. It resulted in excellent contrast between lesions and normal tissues. Together, the abilities to sensitively separate the lesions from adjacent normal tissues with the aid of a FMT/CT dual-model imaging approach make the targeting nanoparticles a useful tool for the diagnostics of breast cancer.

  10. Macro-level pedestrian and bicycle crash analysis: Incorporating spatial spillover effects in dual state count models.

    Science.gov (United States)

    Cai, Qing; Lee, Jaeyoung; Eluru, Naveen; Abdel-Aty, Mohamed

    2016-08-01

    This study attempts to explore the viability of dual-state models (i.e., zero-inflated and hurdle models) for traffic analysis zones (TAZs) based pedestrian and bicycle crash frequency analysis. Additionally, spatial spillover effects are explored in the models by employing exogenous variables from neighboring zones. The dual-state models such as zero-inflated negative binomial and hurdle negative binomial models (with and without spatial effects) are compared with the conventional single-state model (i.e., negative binomial). The model comparison for pedestrian and bicycle crashes revealed that the models that considered observed spatial effects perform better than the models that did not consider the observed spatial effects. Across the models with spatial spillover effects, the dual-state models especially zero-inflated negative binomial model offered better performance compared to single-state models. Moreover, the model results clearly highlighted the importance of various traffic, roadway, and sociodemographic characteristics of the TAZ as well as neighboring TAZs on pedestrian and bicycle crash frequency. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Dual Processing Model for Medical Decision-Making: An Extension to Diagnostic Testing.

    Directory of Open Access Journals (Sweden)

    Athanasios Tsalatsanis

    Full Text Available Dual Processing Theories (DPT assume that human cognition is governed by two distinct types of processes typically referred to as type 1 (intuitive and type 2 (deliberative. Based on DPT we have derived a Dual Processing Model (DPM to describe and explain therapeutic medical decision-making. The DPM model indicates that doctors decide to treat when treatment benefits outweigh its harms, which occurs when the probability of the disease is greater than the so called "threshold probability" at which treatment benefits are equal to treatment harms. Here we extend our work to include a wider class of decision problems that involve diagnostic testing. We illustrate applicability of the proposed model in a typical clinical scenario considering the management of a patient with prostate cancer. To that end, we calculate and compare two types of decision-thresholds: one that adheres to expected utility theory (EUT and the second according to DPM. Our results showed that the decisions to administer a diagnostic test could be better explained using the DPM threshold. This is because such decisions depend on objective evidence of test/treatment benefits and harms as well as type 1 cognition of benefits and harms, which are not considered under EUT. Given that type 1 processes are unique to each decision-maker, this means that the DPM threshold will vary among different individuals. We also showed that when type 1 processes exclusively dominate decisions, ordering a diagnostic test does not affect a decision; the decision is based on the assessment of benefits and harms of treatment. These findings could explain variations in the treatment and diagnostic patterns documented in today's clinical practice.

  12. Dual Processing Model for Medical Decision-Making: An Extension to Diagnostic Testing.

    Science.gov (United States)

    Tsalatsanis, Athanasios; Hozo, Iztok; Kumar, Ambuj; Djulbegovic, Benjamin

    2015-01-01

    Dual Processing Theories (DPT) assume that human cognition is governed by two distinct types of processes typically referred to as type 1 (intuitive) and type 2 (deliberative). Based on DPT we have derived a Dual Processing Model (DPM) to describe and explain therapeutic medical decision-making. The DPM model indicates that doctors decide to treat when treatment benefits outweigh its harms, which occurs when the probability of the disease is greater than the so called "threshold probability" at which treatment benefits are equal to treatment harms. Here we extend our work to include a wider class of decision problems that involve diagnostic testing. We illustrate applicability of the proposed model in a typical clinical scenario considering the management of a patient with prostate cancer. To that end, we calculate and compare two types of decision-thresholds: one that adheres to expected utility theory (EUT) and the second according to DPM. Our results showed that the decisions to administer a diagnostic test could be better explained using the DPM threshold. This is because such decisions depend on objective evidence of test/treatment benefits and harms as well as type 1 cognition of benefits and harms, which are not considered under EUT. Given that type 1 processes are unique to each decision-maker, this means that the DPM threshold will vary among different individuals. We also showed that when type 1 processes exclusively dominate decisions, ordering a diagnostic test does not affect a decision; the decision is based on the assessment of benefits and harms of treatment. These findings could explain variations in the treatment and diagnostic patterns documented in today's clinical practice.

  13. Ontological models with epistemic constraints: Local reconstruction of a dual-rail qubit

    Science.gov (United States)

    Blasiak, Pawel

    2017-10-01

    Restrictions on gaining information may significantly affect perception of the system under study. In this paper we are concerned with mechanisms introducing epistemic constraints in the framework of ontological models and discuss a scheme leading to the minimal operational account which does not rely on the knowledge of the underlying ontology. As a case in point, we construct local ontological model which simulates behaviour of a single quantum particle in dual-rail interferometric circuits. We show that for agents analysing conceivable experimental circuits predictions of the model are indistinguishable from their quantum mechanical counterparts, that is operational account of the model is equivalent to a qubit. Note that it contrasts with the usual understanding the collapse of the wave function as non-local phenomenon, namely the model is local from the construction with any form of 'non-locality' being explained as an epistemic effect due to incomplete information about the system. This illustrates flexibility of the ontological model framework, and in particular the possibility of different interpretations behind the same operational account.

  14. Research Article. Improved Dual Frequency PPP Model Using GPS and BeiDou Observations

    Science.gov (United States)

    Afifi, A.; El-Rabbany, A.

    2017-02-01

    This paper introduces a new dual-frequency precise point positioning (PPP) model, which combines GPS and BeiDou observations. Combining GPS and BeiDou observations in a PPP model offers more visible satellites to the user, which is expected to enhance the satellite geometry and the overall PPP solution in comparison with GPSonly PPP solution. However, combining different GNSS constellations introduces additional biases, which require rigorous modelling, including GNSS time offset and hardware delays. In this research, ionosphere-free linear combination PPP model is developed. The additional biases, which result from combining the GPS and BeiDou observables, are lumped into a new unknown parameter identified as the inter-system bias. Natural Resources Canada's GPSPace PPP software is modified to enable a combined GPS/BeiDou PPP solution and to handle the newly introduced biases. A total of four data sets at four IGS stations are processed to verify the developed PPP model. Precise satellite orbit and clock products from the IGS-MGEX network are used to correct both of the GPS and BeiDou measurements. It is shown that a sub-decimeter positioning accuracy level and 25% reduction in the solution convergence time can be achieved with combining GPS and Bei-Dou observables in a PPP model, in comparison with the GPS-only PPP solution.

  15. Early small-bowel ischemia: dual-energy CT improves conspicuity compared with conventional CT in a swine model.

    Science.gov (United States)

    Potretzke, Theodora A; Brace, Christopher L; Lubner, Meghan G; Sampson, Lisa A; Willey, Bridgett J; Lee, Fred T

    2015-04-01

    To compare dual-energy computed tomography (CT) with conventional CT for the detection of small-bowel ischemia in an experimental animal model. The study was approved by the animal care and use committee and was performed in accordance with the Guide for Care and Use of Laboratory Animals issued by the National Research Council. Ischemic bowel segments (n = 8) were created in swine (n = 4) by means of surgical occlusion of distal mesenteric arteries and veins. Contrast material-enhanced dual-energy CT and conventional single-energy CT (120 kVp) sequences were performed during the portal venous phase with a single-source fast-switching dual-energy CT scanner. Attenuation values and contrast-to-noise ratios of ischemic and perfused segments on iodine material-density, monospectral dual-energy CT (51 keV, 65 keV, and 70 keV), and conventional 120-kVp CT images were compared. Linear mixed-effects models were used for comparisons. The attenuation difference between ischemic and perfused segments was significantly greater on dual-energy 51-keV CT images than on conventional 120-kVp CT images (mean difference, 91.7 HU vs 47.6 HU; P conventional CT by increasing attenuation differences between ischemic and perfused segments on low-kiloelectron volt and iodine material density images. © RSNA, 2014.

  16. Dual regression physiological modeling of resting-state EPI power spectra: Effects of healthy aging.

    Science.gov (United States)

    Viessmann, Olivia; Möller, Harald E; Jezzard, Peter

    2018-02-02

    Aging and disease-related changes in the arteriovasculature have been linked to elevated levels of cardiac cycle-induced pulsatility in the cerebral microcirculation. Functional magnetic resonance imaging (fMRI), acquired fast enough to unalias the cardiac frequency contributions, can be used to study these physiological signals in the brain. Here, we propose an iterative dual regression analysis in the frequency domain to model single voxel power spectra of echo planar imaging (EPI) data using external recordings of the cardiac and respiratory cycles as input. We further show that a data-driven variant, without external physiological traces, produces comparable results. We use this framework to map and quantify cardiac and respiratory contributions in healthy aging. We found a significant increase in the spatial extent of cardiac modulated white matter voxels with age, whereas the overall strength of cardiac-related EPI power did not show an age effect. Copyright © 2018. Published by Elsevier Inc.

  17. Characterization of a Dual CDC7/CDK9 Inhibitor in Multiple Myeloma Cellular Models

    International Nuclear Information System (INIS)

    Natoni, Alessandro; Coyne, Mark R. E.; Jacobsen, Alan; Rainey, Michael D.; O’Brien, Gemma; Healy, Sandra; Montagnoli, Alessia; Moll, Jürgen; O’Dwyer, Michael; Santocanale, Corrado

    2013-01-01

    Two key features of myeloma cells are the deregulation of the cell cycle and the dependency on the expression of the BCL2 family of anti-apoptotic proteins. The cell division cycle 7 (CDC7) is an essential S-phase kinase and emerging CDC7 inhibitors are effective in a variety of preclinical cancer models. These compounds also inhibit CDK9 which is relevant for MCL-1 expression. The activity and mechanism of action of the dual CDC7/CDK9 inhibitor PHA-767491 was assessed in a panel of multiple myeloma cell lines, in primary samples from patients, in the presence of stromal cells and in combination with drugs used in current chemotherapeutic regimens. We report that in all conditions myeloma cells undergo cell death upon PHA-767491 treatment and we report an overall additive effect with melphalan, bortezomib and doxorubicin, thus supporting further assessment of targeting CDC7 and CDK9 in multiple myeloma

  18. Characterization of a Dual CDC7/CDK9 Inhibitor in Multiple Myeloma Cellular Models

    Energy Technology Data Exchange (ETDEWEB)

    Natoni, Alessandro [Centre for Chromosome Biology, School of Natural Sciences National University of Ireland Galway, Galway (Ireland); Coyne, Mark R. E. [Centre for Chromosome Biology, School of Natural Sciences National University of Ireland Galway, Galway (Ireland); Department of Medicine, National University of Ireland Galway, Galway (Ireland); Department of Haematology, Galway University Hospital, Galway (Ireland); Jacobsen, Alan; Rainey, Michael D.; O’Brien, Gemma; Healy, Sandra [Centre for Chromosome Biology, School of Natural Sciences National University of Ireland Galway, Galway (Ireland); Montagnoli, Alessia; Moll, Jürgen [Nerviano Medical Sciences S.r.l., Via Pasteur 10, Nerviano 20014 (Italy); O’Dwyer, Michael, E-mail: michael.odwyer@nuigalway.ie [Department of Medicine, National University of Ireland Galway, Galway (Ireland); Department of Haematology, Galway University Hospital, Galway (Ireland); Santocanale, Corrado, E-mail: michael.odwyer@nuigalway.ie [Centre for Chromosome Biology, School of Natural Sciences National University of Ireland Galway, Galway (Ireland)

    2013-07-24

    Two key features of myeloma cells are the deregulation of the cell cycle and the dependency on the expression of the BCL2 family of anti-apoptotic proteins. The cell division cycle 7 (CDC7) is an essential S-phase kinase and emerging CDC7 inhibitors are effective in a variety of preclinical cancer models. These compounds also inhibit CDK9 which is relevant for MCL-1 expression. The activity and mechanism of action of the dual CDC7/CDK9 inhibitor PHA-767491 was assessed in a panel of multiple myeloma cell lines, in primary samples from patients, in the presence of stromal cells and in combination with drugs used in current chemotherapeutic regimens. We report that in all conditions myeloma cells undergo cell death upon PHA-767491 treatment and we report an overall additive effect with melphalan, bortezomib and doxorubicin, thus supporting further assessment of targeting CDC7 and CDK9 in multiple myeloma.

  19. Simulation strategies for the massless lattice Schwinger model in the dual formulation

    Science.gov (United States)

    Göschl, Daniel; Gattringer, Christof; Lehmann, Alexander; Weis, Christoph

    2017-11-01

    The dual form of the massless Schwinger model on the lattice overcomes the complex action problems from two sources: a topological term, as well as non-zero chemical potential, making these physically interesting cases accessible to Monte Carlo simulations. The partition function is represented as a sum over fermion loops, dimers and plaquette-surfaces such that all contributions are real and positive. However, these new variables constitute a highly constrained system and suitable update strategies have to be developed. In this exploratory study we present an approach based on locally growing plaquette-surfaces surrounded by fermion loop segments combined with a worm based strategy for updating chains of dimers, as well as winding fermion loops. The update strategy is checked with conventional simulations as well as reference data from exact summation on small volumes and we discuss some physical implications of the results.

  20. Testing crossover effects in an actor-partner interdependence model among Chinese dual-earner couples.

    Science.gov (United States)

    Liu, Huimin; Cheung, Fanny M

    2015-03-01

    The purpose of the present study is to examine the crossover effects from one partner's work-family interface (work-family conflict [WFC] and work-family enrichment [WFE]) to the other partner's four outcomes (psychological strain, life satisfaction, marital satisfaction and job satisfaction) in a sample of Chinese dual-earner couples. Married couples (N = 361) completed a battery of questionnaires, including the work-family interface scale, the psychological strain scale, the life, marital, as well as job satisfaction scale. Results from the actor-partner interdependence model (APIM) analyses showed that wives' WFE was negatively associated with husbands' psychological strain, and positively associated with husbands' life, marital and job satisfaction. Furthermore, husbands' WFC was negatively related to wives' marital satisfaction, whereas husbands' WFE was positively related to wives' marital satisfaction. Theoretical and practical implications were discussed, and future research directions were provided. © 2014 International Union of Psychological Science.

  1. The uncovered parity properties of the Czech Koruna

    Czech Academy of Sciences Publication Activity Database

    Derviz, Alexis

    2002-01-01

    Roč. 11, č. 1 (2002), s. 17-37 ISSN 1210-0455 R&D Projects: GA AV ČR KSK1019101 Institutional research plan: CEZ:AV0Z1075907 Keywords : uncovered parity * asset prices * international consumption-based capital asset pricing model Subject RIV: AH - Economics

  2. Testing a dual-systems model of adolescent brain development using resting-state connectivity analyses.

    Science.gov (United States)

    van Duijvenvoorde, A C K; Achterberg, M; Braams, B R; Peters, S; Crone, E A

    2016-01-01

    The current study aimed to test a dual-systems model of adolescent brain development by studying changes in intrinsic functional connectivity within and across networks typically associated with cognitive-control and affective-motivational processes. To this end, resting-state and task-related fMRI data were collected of 269 participants (ages 8-25). Resting-state analyses focused on seeds derived from task-related neural activation in the same participants: the dorsal lateral prefrontal cortex (dlPFC) from a cognitive rule-learning paradigm and the nucleus accumbens (NAcc) from a reward-paradigm. Whole-brain seed-based resting-state analyses showed an age-related increase in dlPFC connectivity with the caudate and thalamus, and an age-related decrease in connectivity with the (pre)motor cortex. nAcc connectivity showed a strengthening of connectivity with the dorsal anterior cingulate cortex (ACC) and subcortical structures such as the hippocampus, and a specific age-related decrease in connectivity with the ventral medial PFC (vmPFC). Behavioral measures from both functional paradigms correlated with resting-state connectivity strength with their respective seed. That is, age-related change in learning performance was mediated by connectivity between the dlPFC and thalamus, and age-related change in winning pleasure was mediated by connectivity between the nAcc and vmPFC. These patterns indicate (i) strengthening of connectivity between regions that support control and learning, (ii) more independent functioning of regions that support motor and control networks, and (iii) more independent functioning of regions that support motivation and valuation networks with age. These results are interpreted vis-à-vis a dual-systems model of adolescent brain development. Copyright © 2015. Published by Elsevier Inc.

  3. Paleozoic Nymphal Wing Pads Support Dual Model of Insect Wing Origins.

    Science.gov (United States)

    Prokop, Jakub; Pecharová, Martina; Nel, André; Hörnschemeyer, Thomas; Krzemińska, Ewa; Krzemiński, Wiesław; Engel, Michael S

    2017-01-23

    The appearance of wings in insects, early in their evolution [1], has been one of the more critical innovations contributing to their extraordinary diversity. Despite the conspicuousness and importance of wings, the origin of these structures has been difficult to resolve and represented one of the "abominable mysteries" in evolutionary biology [2]. More than a century of debate has boiled the matter down to two competing alternatives-one of wings representing an extension of the thoracic notum, the other stating that they are appendicular derivations from the lateral body wall. Recently, a dual model has been supported by genomic and developmental data [3-6], representing an amalgamation of elements from both the notal and pleural hypotheses. Here, we reveal crucial information from the wing pad joints of Carboniferous palaeodictyopteran insect nymphs using classical and high-tech techniques. These nymphs had three pairs of wing pads that were medially articulated to the thorax but also broadly contiguous with the notum anteriorly and posteriorly (details unobservable in modern insects), supporting their overall origin from the thoracic notum as well as the expected medial, pleural series of axillary sclerites. Our study provides support for the formation of the insect wing from the thoracic notum as well as the already known pleural elements of the arthropodan leg. These results support the unique, dual model for insect wing origins and the convergent reduction of notal fusion in more derived clades, presumably due to wing rotation during development, and they help to bring resolution to this long-standing debate. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Compound analysis of gallstones using dual energy computed tomography-Results in a phantom model

    International Nuclear Information System (INIS)

    Bauer, Ralf W.; Schulz, Julian R.; Zedler, Barbara; Graf, Thomas G.; Vogl, Thomas J.

    2010-01-01

    Purpose: The potential of dual energy computed tomography (DECT) for the analysis of gallstone compounds was investigated. The main goal was to find parameters, that can reliably define high percentage (>70%) cholesterol stones without calcium components. Materials and methods: 35 gallstones were analyzed with DECT using a phantom model. Stone samples were put into specimen containers filled with formalin. Containers were put into a water-filled cylindrical acrylic glass phantom. DECT scans were performed using a tube voltage/current of 140 kV/83 mAs (tube A) and 80 kV/340 mAs (tube B). ROI-measurements to determine CT attenuation of each sector of the stones that had different appearance on the CT images were performed. Finally, semi-quantitative infrared spectroscopy (FTIR) of these sectors was performed for chemical analysis. Results: ROI-measurements were performed in 45 different sectors in 35 gallstones. Sectors containing >70% of cholesterol and no calcium component (n = 20) on FTIR could be identified with 95% sensitivity and 100% specificity on DECT. These sectors showed typical attenuation of -8 ± 4 HU at 80 kV and +22 ± 3 HU at 140 kV. Even the presence of a small calcium component (<10%) hindered the reliable identification of cholesterol components as such. Conclusion: Dual energy CT allows for reliable identification of gallstones containing a high percentage of cholesterol and no calcium component in this pre-clinical phantom model. Results from in vivo or anthropomorphic phantom trials will have to confirm these results. This may enable the identification of patients eligible for non-surgical treatment options in the future.

  5. Dual Supervised Learning

    OpenAIRE

    Xia, Yingce; Qin, Tao; Chen, Wei; Bian, Jiang; Yu, Nenghai; Liu, Tie-Yan

    2017-01-01

    Many supervised learning tasks are emerged in dual forms, e.g., English-to-French translation vs. French-to-English translation, speech recognition vs. text to speech, and image classification vs. image generation. Two dual tasks have intrinsic connections with each other due to the probabilistic correlation between their models. This connection is, however, not effectively utilized today, since people usually train the models of two dual tasks separately and independently. In this work, we p...

  6. Dual-porosity model of solute diffusion in biological tissue modified by electroporation.

    Science.gov (United States)

    Mahnič-Kalamiza, Samo; Miklavčič, Damijan; Vorobiev, Eugène

    2014-07-01

    In many electroporation applications mass transport in biological tissue is of primary concern. This paper presents a theoretical advancement in the field and gives some examples of model use in electroporation applications. The study focuses on post-treatment solute diffusion. We use a dual-porosity approach to describe solute diffusion in electroporated biological tissue. The cellular membrane presents a hindrance to solute transport into the extracellular space and is modeled as electroporation-dependent porosity, assigned to the intracellular space (the finite rate of mass transfer within an individual cell is not accounted for, for reasons that we elaborate on). The second porosity is that of the extracellular space, through which solute vacates a block of tissue. The model can be used to study extraction out of or introduction of solutes into tissue, and we give three examples of application, a full account of model construction, validation with experiments, and a parametrical analysis. To facilitate easy implementation and experimentation by the reader, the complete derivation of the analytical solution for a simplified example is presented. Validation is done by comparing model results to experimentally-obtained data; we modeled kinetics of sucrose extraction by diffusion from sugar beet tissue in laboratory-scale experiments. The parametrical analysis demonstrates the importance of selected physicochemical and geometrical properties of the system, illustrating possible outcomes of applying the model to different electroporation applications. The proposed model is a new platform that supports rapid extension by state-of-the-art models of electroporation phenomena, developed as latest achievements in the field of electroporation. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Affine Poisson Groups and WZW Model

    Directory of Open Access Journals (Sweden)

    Ctirad Klimcík

    2008-01-01

    Full Text Available We give a detailed description of a dynamical system which enjoys a Poisson-Lie symmetry with two non-isomorphic dual groups. The system is obtained by taking the q → ∞ limit of the q-deformed WZW model and the understanding of its symmetry structure results in uncovering an interesting duality of its exchange relations.

  8. The Cortical Organization of Speech Processing: Feedback Control and Predictive Coding the Context of a Dual-Stream Model

    Science.gov (United States)

    Hickok, Gregory

    2012-01-01

    Speech recognition is an active process that involves some form of predictive coding. This statement is relatively uncontroversial. What is less clear is the source of the prediction. The dual-stream model of speech processing suggests that there are two possible sources of predictive coding in speech perception: the motor speech system and the…

  9. Why did distinct types of dual-earner models in Czech, Slovak and East German societies develop and persist?

    Czech Academy of Sciences Publication Activity Database

    Hašková, Hana; Klenner, Ch.

    2010-01-01

    Roč. 22, č. 3 (2010), s. 266-288 ISSN 1437-2940 R&D Projects: GA AV ČR IAA700280901; GA ČR GAP404/10/0021 Institutional research plan: CEZ:AV0Z70280505 Keywords : dual earner model * Central and Eastern Europe Subject RIV: AO - Sociology , Demography Impact factor: 0.037, year: 2010

  10. A dual process model of diversity outcomes : The case of the South African Police Service in the Pretoria area

    NARCIS (Netherlands)

    Jackson, L.T.B.; van de Vijver, F.J.R.; Molokoane, D.H.

    2013-01-01

    Orientation: The study addresses the question of how employees of the South African Police Service (SAPS) cope with intercultural relations in an increasingly diverse organisation. Research purpose: A dual-process model of diversity outcomes was tested in which a distinction is made between a

  11. Temporal dynamics of interference in Simon and Eriksen tasks considered within the context of a dual-process model.

    NARCIS (Netherlands)

    Mansfield, K.L.; van der Molen, M.W.; Falkenstein, M.; van Boxtel, G.J.M.

    2013-01-01

    Behavioral and brain potential measures were employed to compare interference in Eriksen and Simon tasks. Assuming a dual-process model of interference elicited in speeded response tasks, we hypothesized that only lateralized stimuli in the Simon task induce fast S–R priming via direct unconditional

  12. Hedonic tone and activation in the mood-creativity link: towards a dual pathway to creativity model

    NARCIS (Netherlands)

    de Dreu, C.K.W.; Baas, M.; Nijstad, B.A.

    2008-01-01

    To understand when and why mood states influence creativity, the authors developed and tested a dual pathway to creativity model; creative fluency (number of ideas or insights) and originality (novelty) are functions of cognitive flexibility, persistence, or some combination thereof. Invoking work

  13. Hedonic tone and activation level in the mood-creativity link : Toward a dual pathway to creativity model

    NARCIS (Netherlands)

    De Dreu, Carsten K. W.; Baas, Matthijs; Nijstad, Bernard A.

    To understand when and why mood states influence creativity, the authors developed and tested a dual pathway to creativity model; creative fluency (number of ideas or insights) and originality (novelty) are functions of cognitive flexibility, persistence, or some combination thereof. Invoking work

  14. Testing a Dual Process Model of Gender-Based Violence: A Laboratory Examination.

    Science.gov (United States)

    Berke, Danielle S; Zeichner, Amos

    2016-01-01

    The dire impact of gender-based violence on society compels development of models comprehensive enough to capture the diversity of its forms. Research has established hostile sexism (HS) as a robust predictor of gender-based violence. However, to date, research has yet to link men's benevolent sexism (BS) to physical aggression toward women, despite correlations between BS and HS and between BS and victim blaming. One model, the opposing process model of benevolent sexism (Sibley & Perry, 2010), suggests that, for men, BS acts indirectly through HS to predict acceptance of hierarchy-enhancing social policy as an expression of a preference for in-group dominance (i. e., social dominance orientation [SDO]). The extent to which this model applies to gender-based violence remains untested. Therefore, in this study, 168 undergraduate men in a U. S. university participated in a competitive reaction time task, during which they had the option to shock an ostensible female opponent as a measure of gender-based violence. Results of multiple-mediation path analyses indicated dual pathways potentiating gender-based violence and highlight SDO as a particularly potent mechanism of this violence. Findings are discussed in terms of group dynamics and norm-based violence prevention.

  15. Mathematical Modeling of Dual Layer Shell Type Recuperation System for Biogas Dehumidification

    Science.gov (United States)

    Gendelis, S.; Timuhins, A.; Laizans, A.; Bandeniece, L.

    2015-12-01

    The main aim of the current paper is to create a mathematical model for dual layer shell type recuperation system, which allows reducing the heat losses from the biomass digester and water amount in the biogas without any additional mechanical or chemical components. The idea of this system is to reduce the temperature of the outflowing gas by creating two-layered counter-flow heat exchanger around the walls of biogas digester, thus increasing a thermal resistance and the gas temperature, resulting in a condensation on a colder surface. Complex mathematical model, including surface condensation, is developed for this type of biogas dehumidifier and the parameter study is carried out for a wide range of parameters. The model is reduced to 1D case to make numerical calculations faster. It is shown that latent heat of condensation is very important for the total heat balance and the condensation rate is highly dependent on insulation between layers and outside temperature. Modelling results allow finding optimal geometrical parameters for the known gas flow and predicting the condensation rate for different system setups and seasons.

  16. Identifying western yellow-billed cuckoo breeding habitat with a dual modelling approach

    Science.gov (United States)

    Johnson, Matthew J.; Hatten, James R.; Holmes, Jennifer A.; Shafroth, Patrick B.

    2017-01-01

    The western population of the yellow-billed cuckoo (Coccyzus americanus) was recently listed as threatened under the federal Endangered Species Act. Yellow-billed cuckoo conservation efforts require the identification of features and area requirements associated with high quality, riparian forest habitat at spatial scales that range from nest microhabitat to landscape, as well as lower-suitability areas that can be enhanced or restored. Spatially explicit models inform conservation efforts by increasing ecological understanding of a target species, especially at landscape scales. Previous yellow-billed cuckoo modelling efforts derived plant-community maps from aerial photography, an expensive and oftentimes inconsistent approach. Satellite models can remotely map vegetation features (e.g., vegetation density, heterogeneity in vegetation density or structure) across large areas with near perfect repeatability, but they usually cannot identify plant communities. We used aerial photos and satellite imagery, and a hierarchical spatial scale approach, to identify yellow-billed cuckoo breeding habitat along the Lower Colorado River and its tributaries. Aerial-photo and satellite models identified several key features associated with yellow-billed cuckoo breeding locations: (1) a 4.5 ha core area of dense cottonwood-willow vegetation, (2) a large native, heterogeneously dense forest (72 ha) around the core area, and (3) moderately rough topography. The odds of yellow-billed cuckoo occurrence decreased rapidly as the amount of tamarisk cover increased or when cottonwood-willow vegetation was limited. We achieved model accuracies of 75–80% in the project area the following year after updating the imagery and location data. The two model types had very similar probability maps, largely predicting the same areas as high quality habitat. While each model provided unique information, a dual-modelling approach provided a more complete picture of yellow-billed cuckoo habitat

  17. Modeling intraparticle transports during propylene polymerizations using supported metallocene and dual function metallocene as catalysts: Single particle model

    Directory of Open Access Journals (Sweden)

    Li Hua-Rong

    2014-01-01

    Full Text Available Two improved multigrain models (MGMs for preparing homopolypropylene and long chain branched polypropylene via propylene polymerization using silica-supported metallocene or dual function metallocene as catalysts are presented in this paper. The presented models are used to predict the intraparticle flow fields involved in the polymerizations. The simulation results show that the flow field distributions involve dare basically identical. The results also show that both the two polymerization processes have an initiation stage and the controlling step for them is reaction-diffusion-reaction with the polymerization proceeding. Furthermore, the simulation results show that the intra particle mass transfer resistance has significant effect on the polymerization but the heat transfer resistance can be ignored.

  18. Numerical model (switchable/dual model) of the human head for rigid body and finite elements applications.

    Science.gov (United States)

    Tabacu, Stefan

    2015-01-01

    In this paper, a methodology for the development and validation of a numerical model of the human head using generic procedures is presented. All steps required, starting with the model generation, model validation and applications will be discussed. The proposed model may be considered as a dual one due to its capabilities to switch from deformable to a rigid body according to the application's requirements. The first step is to generate the numerical model of the human head using geometry files or medical images. The required stiffness and damping for the elastic connection used for the rigid body model are identified by performing a natural frequency analysis. The presented applications for model validation are related to impact analysis. The first case is related to Nahum's (Nahum and Smith 1970) experiments pressure data being evaluated and a pressure map generated using the results from discrete elements. For the second case, the relative displacement between the brain and the skull is evaluated according to Hardy's (Hardy WH, Foster CD, Mason, MJ, Yang KH, King A, Tashman S. 2001.Investigation of head injury mechanisms using neutral density technology and high-speed biplanar X-ray. Stapp Car Crash J. 45:337-368, SAE Paper 2001-22-0016) experiments. The main objective is to validate the rigid model as a quick and versatile tool for acquiring the input data for specific brain analyses.

  19. Trend-Residual Dual Modeling for Detection of Outliers in Low-Cost GPS Trajectories.

    Science.gov (United States)

    Chen, Xiaojian; Cui, Tingting; Fu, Jianhong; Peng, Jianwei; Shan, Jie

    2016-12-01

    Low-cost GPS (receiver) has become a ubiquitous and integral part of our daily life. Despite noticeable advantages such as being cheap, small, light, and easy to use, its limited positioning accuracy devalues and hampers its wide applications for reliable mapping and analysis. Two conventional techniques to remove outliers in a GPS trajectory are thresholding and Kalman-based methods, which are difficult in selecting appropriate thresholds and modeling the trajectories. Moreover, they are insensitive to medium and small outliers, especially for low-sample-rate trajectories. This paper proposes a model-based GPS trajectory cleaner. Rather than examining speed and acceleration or assuming a pre-determined trajectory model, we first use cubic smooth spline to adaptively model the trend of the trajectory. The residuals, i.e., the differences between the trend and GPS measurements, are then further modeled by time series method. Outliers are detected by scoring the residuals at every GPS trajectory point. Comparing to the conventional procedures, the trend-residual dual modeling approach has the following features: (a) it is able to model trajectories and detect outliers adaptively; (b) only one critical value for outlier scores needs to be set; (c) it is able to robustly detect unapparent outliers; and (d) it is effective in cleaning outliers for GPS trajectories with low sample rates. Tests are carried out on three real-world GPS trajectories datasets. The evaluation demonstrates an average of 9.27 times better performance in outlier detection for GPS trajectories than thresholding and Kalman-based techniques.

  20. Trend-Residual Dual Modeling for Detection of Outliers in Low-Cost GPS Trajectories

    Directory of Open Access Journals (Sweden)

    Xiaojian Chen

    2016-12-01

    Full Text Available Low-cost GPS (receiver has become a ubiquitous and integral part of our daily life. Despite noticeable advantages such as being cheap, small, light, and easy to use, its limited positioning accuracy devalues and hampers its wide applications for reliable mapping and analysis. Two conventional techniques to remove outliers in a GPS trajectory are thresholding and Kalman-based methods, which are difficult in selecting appropriate thresholds and modeling the trajectories. Moreover, they are insensitive to medium and small outliers, especially for low-sample-rate trajectories. This paper proposes a model-based GPS trajectory cleaner. Rather than examining speed and acceleration or assuming a pre-determined trajectory model, we first use cubic smooth spline to adaptively model the trend of the trajectory. The residuals, i.e., the differences between the trend and GPS measurements, are then further modeled by time series method. Outliers are detected by scoring the residuals at every GPS trajectory point. Comparing to the conventional procedures, the trend-residual dual modeling approach has the following features: (a it is able to model trajectories and detect outliers adaptively; (b only one critical value for outlier scores needs to be set; (c it is able to robustly detect unapparent outliers; and (d it is effective in cleaning outliers for GPS trajectories with low sample rates. Tests are carried out on three real-world GPS trajectories datasets. The evaluation demonstrates an average of 9.27 times better performance in outlier detection for GPS trajectories than thresholding and Kalman-based techniques.

  1. Dual-extrusion 3D printing of anatomical models for education.

    Science.gov (United States)

    Smith, Michelle L; Jones, James F X

    2018-01-01

    Two material 3D printing is becoming increasingly popular, inexpensive and accessible. In this paper, freely available printable files and dual extrusion fused deposition modelling were combined to create a number of functional anatomical models. To represent muscle and bone FilaFlex 3D flexible filament and polylactic acid (PLA) filament were extruded respectively via a single 0.4 mm nozzle using a Big Builder printer. For each filament, cubes (5 mm 3 ) were printed and analyzed for X, Y, and Z accuracy. The PLA printed cubes resulted in errors averaging just 1.2% across all directions but for FilaFlex 3D printed cubes the errors were statistically significantly greater (average of 3.2%). As an exemplar, a focus was placed on the muscles, bones and cartilage of upper airway and neck. The resulting single prints combined flexible and hard structures. A single print model of the vocal cords was constructed which permitted movement of the arytenoids on the cricoid cartilage and served to illustrate the action of intrinsic laryngeal muscles. As University libraries become increasingly engaged in offering inexpensive 3D printing services it may soon become common place for both student and educator to access websites, download free models or 3D body parts and only pay the costs of print consumables. Novel models can be manufactured as dissectible, functional multi-layered units and offer rich possibilities for sectional and/or reduced anatomy. This approach can liberate the anatomist from constraints of inflexible hard models or plastinated specimens and engage in the design of class specific models of the future. Anat Sci Educ 11: 65-72. © 2017 American Association of Anatomists. © 2017 American Association of Anatomists.

  2. Prediction models for performance and emissions of a dual fuel CI ...

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... Dual fuel engines are being used these days to overcome shortage of fossil fuels and fulfill stringent exhaust gas emission regulations. They have several advantages over conventional diesel engines. In this context, this paper makes use of experimental results obtained from a dual fuel engine for ...

  3. Classifying Chinese children with dyslexia by dual-route and triangle models of Chinese reading.

    Science.gov (United States)

    Wang, Li-Chih; Yang, Hsien-Ming

    2014-11-01

    This present study focuses on classifying developmental dyslexia by combining two famous models, the dual-route model and the triangle model of Chinese reading, re-examining validity of the subtypes, and observing the error types of word recognition for each subtype. Sixty-sixth graders with dyslexia in Chinese and 45 sixth graders who were matched by age and IQ with the dyslexic group were involved in the present study. Twelve (20%) sixth graders from the dyslexic group were classified as having phonological dyslexia, 11 (18.3%) were classified as surface dyslexia, 12 (20%) were classified as deep dyslexia, and five (8.3%) of them were classified as displaying more than one kind of deficit. Besides, still more than half (31; 51.7%) of the dyslexic group did not belong to any subtypes here. These subtypes had a good validity based on comparison of their phonological awareness, orthography, and semantics. Finally, for their error types of word recognition, both children with multiple-deficit dyslexia and children with non-subtype dyslexia showed a proportional pattern of six kinds of errors. Children with phonological dyslexia showed more phonetic errors and analogy errors, children with surface dyslexia showed more visual errors and analogy errors, and children with deep dyslexia showed more semantic errors and selective errors. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Topological Symmetry, Spin Liquids and CFT Duals of Polyakov Model with Massless Fermions

    Energy Technology Data Exchange (ETDEWEB)

    Unsal, Mithat

    2008-04-30

    We prove the absence of a mass gap and confinement in the Polyakov model with massless complex fermions in any representation of the gauge group. A U(1){sub *} topological shift symmetry protects the masslessness of one dual photon. This symmetry emerges in the IR as a consequence of the Callias index theorem and abelian duality. For matter in the fundamental representation, the infrared limits of this class of theories interpolate between weakly and strongly coupled conformal field theory (CFT) depending on the number of flavors, and provide an infinite class of CFTs in d = 3 dimensions. The long distance physics of the model is same as certain stable spin liquids. Altering the topology of the adjoint Higgs field by turning it into a compact scalar does not change the long distance dynamics in perturbation theory, however, non-perturbative effects lead to a mass gap for the gauge fluctuations. This provides conceptual clarity to many subtle issues about compact QED{sub 3} discussed in the context of quantum magnets, spin liquids and phase fluctuation models in cuprate superconductors. These constructions also provide new insights into zero temperature gauge theory dynamics on R{sup 2,1} and R{sup 2,1} x S{sup 1}. The confined versus deconfined long distance dynamics is characterized by a discrete versus continuous topological symmetry.

  5. Experimental validation of a theoretical model of dual wavelength photoacoustic (PA) excitation in fluorophores

    Science.gov (United States)

    Märk, Julia; Theiss, Christoph; Schmitt, Franz-Josef; Laufer, Jan

    2015-03-01

    Fluorophores, such as exogenous dyes and genetically expressed proteins, exhibit radiative relaxation with long excited state lifetimes. This can be exploited for PA detection based on dual wavelength excitation using pump and probe wavelengths that coincide with the absorption and emission spectra, respectively. While the pump pulse raises the fluorophore to a long-lived excited state, simultaneous illumination with the probe pulse reduces the excited state lifetime due to stimulated emission (SE).This leads to a change in thermalized energy, and hence PA signal amplitude, compared to single wavelength illumination. By introducing a time delay between pump and probe pulses, the change in PA amplitude can be modulated. Since the effect is not observed in endogenous chromophores, it provides a contrast mechanism for the detection of fluorophores via PA difference imaging. In this study, a theoretical model of the PA signal generation in fluorophores was developed and experimentally validated. The model is based on a system of coupled rate equations, which describe the spatial and temporal changes in the population of the molecular energy levels of a fluorophore as a function of pump-probe energy and concentration. This allows the prediction of the thermalized energy distribution, and hence the time-resolved PA signal amplitude. The model was validated by comparing its predictions to PA signals measured in solutions of rhodamine 6G, a well-known laser dye, and Atto680, a NIR fluorophore.

  6. Modeling of Dual Gate Material Hetero-dielectric Strained PNPN TFET for Improved ON Current

    Science.gov (United States)

    Kumari, Tripty; Saha, Priyanka; Dash, Dinesh Kumar; Sarkar, Subir Kumar

    2018-01-01

    The tunnel field effect transistor (TFET) is considered to be a promising alternative device for future low-power VLSI circuits due to its steep subthreshold slope, low leakage current and its efficient performance at low supply voltage. However, the main challenging issue associated with realizing TFET for wide scale applications is its low ON current. To overcome this, a dual gate material with the concept of dielectric engineering has been incorporated into conventional TFET structure to tune the tunneling width at source-channel interface allowing significant flow of carriers. In addition to this, N+ pocket is implanted at source-channel junction of the proposed structure and the effect of strain is added for exploring the performance of the model in nanoscale regime. All these added features upgrade the device characteristics leading to higher ON current, low leakage and low threshold voltage. The present work derives the surface potential, electric field expression and drain current by solving 2D Poisson's equation at different boundary conditions. A comparative analysis of proposed model with conventional TFET has been done to establish the superiority of the proposed structure. All analytical results have been compared with the results obtained in SILVACO ATLAS device simulator to establish the accuracy of the derived analytical model.

  7. Hydraulic behaviour of a partially uncovered core

    International Nuclear Information System (INIS)

    Fischer, K.; Hafner, W.

    1989-10-01

    A critical review of experimental data and theoretical models relevant to the thermohydraulic processes in a partially uncovered core has been performed. Presently available optimized thermohydraulic codes should be able to predict swell level elevations within an error band of ± 0.5 m. Rod temperature rising velocities could be predicted within an error bandwidth of ± 10%, provided the correct rod heat capacity is given. A general statement about the accuracy of predicted rod temperatures is not possible because the errors increase with simulation time. Highest errors are expected for long transients with low heating rates and low steam velocities. As a result, three areas for additional research are suggested: - a high-pressure test at 120 bar to complete the void correlation data base, - a low steam flow - low power experiment to improve heat transfer correlations, - a numerical investigation of three-dimensional effects in the reactor core with unequally heated rod bundles. For the present state of 1-dimensional experiments and models, suggestions for a satisfactory modeling have been derived. The suggested further work could improve the modelling capabilities and the code reliability for some limiting cases like high pressure boil-off, low-power long-term steam cooling, and unequal heating of neighbouring bundles considerably

  8. Smouldering (thermal) remediation of soil contaminated with industrial organic liquids: novel insights into heat transfer and kinetics uncovered by integrating experiments and modelling

    Science.gov (United States)

    Gerhard, J.; Zanoni, M. A. B.; Torero, J. L.

    2017-12-01

    Smouldering (i.e., flameless combustion) underpins the technology Self-sustaining Treatment for Active Remediation (STAR). STAR achieves the in situ destruction of nonaqueous phase liquids (NAPLs) by generating a self-sustained smouldering reaction that propagates through the source zone. This research explores the nature of the travelling reaction and the influence of key in situ and engineered characteristics. A novel one-dimensional numerical model was developed (in COMSOL) to simulate the smouldering remediation of bitumen-contaminated sand. This model was validated against laboratory column experiments. Achieving model validation depended on correctly simulating the energy balance at the reaction front, including properly accounting for heat transfer, smouldering kinetics, and heat losses. Heat transfer between soil and air was demonstrated to be generally not at equilibrium. Moreover, existing heat transfer correlations were found to be inappropriate for the low air flow Reynold's numbers (Re < 30) relevant in this and similar thermal remediation systems. Therefore, a suite of experiments were conducted to generate a new heat transfer correlation, which generated correct simulations of convective heat flow through soil. Moreover, it was found that, for most cases of interest, a simple two-step pyrolysis/oxidation set of kinetic reactions was sufficient. Arrhenius parameters, calculated independently from thermogravimetric experiments, allowed the reaction kinetics to be validated in the smouldering model. Furthermore, a simple heat loss term sufficiently accounted for radial heat losses from the column. Altogether, these advances allow this simple model to reasonably predict the self-sustaining process including the peak reaction temperature, the reaction velocity, and the complete destruction of bitumen behind the front. Simulations with the validated model revealed numerous unique insights, including how the system inherently recycles energy, how air flow

  9. Construction of anthropomorphic hybrid, dual-lattice voxel models for optimizing image quality and dose in radiography

    Science.gov (United States)

    Petoussi-Henss, Nina; Becker, Janine; Greiter, Matthias; Schlattl, Helmut; Zankl, Maria; Hoeschen, Christoph

    2014-03-01

    In radiography there is generally a conflict between the best image quality and the lowest possible patient dose. A proven method of dosimetry is the simulation of radiation transport in virtual human models (i.e. phantoms). However, while the resolution of these voxel models is adequate for most dosimetric purposes, they cannot provide the required organ fine structures necessary for the assessment of the imaging quality. The aim of this work is to develop hybrid/dual-lattice voxel models (called also phantoms) as well as simulation methods by which patient dose and image quality for typical radiographic procedures can be determined. The results will provide a basis to investigate by means of simulations the relationships between patient dose and image quality for various imaging parameters and develop methods for their optimization. A hybrid model, based on NURBS (Non Linear Uniform Rational B-Spline) and PM (Polygon Mesh) surfaces, was constructed from an existing voxel model of a female patient. The organs of the hybrid model can be then scaled and deformed in a non-uniform way i.e. organ by organ; they can be, thus, adapted to patient characteristics without losing their anatomical realism. Furthermore, the left lobe of the lung was substituted by a high resolution lung voxel model, resulting in a dual-lattice geometry model. "Dual lattice" means in this context the combination of voxel models with different resolution. Monte Carlo simulations of radiographic imaging were performed with the code EGS4nrc, modified such as to perform dual lattice transport. Results are presented for a thorax examination.

  10. Implementation science: a role for parallel dual processing models of reasoning?

    Science.gov (United States)

    Sladek, Ruth M; Phillips, Paddy A; Bond, Malcolm J

    2006-01-01

    Background A better theoretical base for understanding professional behaviour change is needed to support evidence-based changes in medical practice. Traditionally strategies to encourage changes in clinical practices have been guided empirically, without explicit consideration of underlying theoretical rationales for such strategies. This paper considers a theoretical framework for reasoning from within psychology for identifying individual differences in cognitive processing between doctors that could moderate the decision to incorporate new evidence into their clinical decision-making. Discussion Parallel dual processing models of reasoning posit two cognitive modes of information processing that are in constant operation as humans reason. One mode has been described as experiential, fast and heuristic; the other as rational, conscious and rule based. Within such models, the uptake of new research evidence can be represented by the latter mode; it is reflective, explicit and intentional. On the other hand, well practiced clinical judgments can be positioned in the experiential mode, being automatic, reflexive and swift. Research suggests that individual differences between people in both cognitive capacity (e.g., intelligence) and cognitive processing (e.g., thinking styles) influence how both reasoning modes interact. This being so, it is proposed that these same differences between doctors may moderate the uptake of new research evidence. Such dispositional characteristics have largely been ignored in research investigating effective strategies in implementing research evidence. Whilst medical decision-making occurs in a complex social environment with multiple influences and decision makers, it remains true that an individual doctor's judgment still retains a key position in terms of diagnostic and treatment decisions for individual patients. This paper argues therefore, that individual differences between doctors in terms of reasoning are important

  11. Implementation science: a role for parallel dual processing models of reasoning?

    Directory of Open Access Journals (Sweden)

    Phillips Paddy A

    2006-05-01

    Full Text Available Abstract Background A better theoretical base for understanding professional behaviour change is needed to support evidence-based changes in medical practice. Traditionally strategies to encourage changes in clinical practices have been guided empirically, without explicit consideration of underlying theoretical rationales for such strategies. This paper considers a theoretical framework for reasoning from within psychology for identifying individual differences in cognitive processing between doctors that could moderate the decision to incorporate new evidence into their clinical decision-making. Discussion Parallel dual processing models of reasoning posit two cognitive modes of information processing that are in constant operation as humans reason. One mode has been described as experiential, fast and heuristic; the other as rational, conscious and rule based. Within such models, the uptake of new research evidence can be represented by the latter mode; it is reflective, explicit and intentional. On the other hand, well practiced clinical judgments can be positioned in the experiential mode, being automatic, reflexive and swift. Research suggests that individual differences between people in both cognitive capacity (e.g., intelligence and cognitive processing (e.g., thinking styles influence how both reasoning modes interact. This being so, it is proposed that these same differences between doctors may moderate the uptake of new research evidence. Such dispositional characteristics have largely been ignored in research investigating effective strategies in implementing research evidence. Whilst medical decision-making occurs in a complex social environment with multiple influences and decision makers, it remains true that an individual doctor's judgment still retains a key position in terms of diagnostic and treatment decisions for individual patients. This paper argues therefore, that individual differences between doctors in terms of

  12. Scaling up stomatal conductance from leaf to canopy using a dual-leaf model for estimating crop evapotranspiration.

    Science.gov (United States)

    Ding, Risheng; Kang, Shaozhong; Du, Taisheng; Hao, Xinmei; Zhang, Yanqun

    2014-01-01

    The dual-source Shuttleworth-Wallace model has been widely used to estimate and partition crop evapotranspiration (λET). Canopy stomatal conductance (Gsc), an essential parameter of the model, is often calculated by scaling up leaf stomatal conductance, considering the canopy as one single leaf in a so-called "big-leaf" model. However, Gsc can be overestimated or underestimated depending on leaf area index level in the big-leaf model, due to a non-linear stomatal response to light. A dual-leaf model, scaling up Gsc from leaf to canopy, was developed in this study. The non-linear stomata-light relationship was incorporated by dividing the canopy into sunlit and shaded fractions and calculating each fraction separately according to absorbed irradiances. The model includes: (1) the absorbed irradiance, determined by separately integrating the sunlit and shaded leaves with consideration of both beam and diffuse radiation; (2) leaf area for the sunlit and shaded fractions; and (3) a leaf conductance model that accounts for the response of stomata to PAR, vapor pressure deficit and available soil water. In contrast to the significant errors of Gsc in the big-leaf model, the predicted Gsc using the dual-leaf model had a high degree of data-model agreement; the slope of the linear regression between daytime predictions and measurements was 1.01 (R2 = 0.98), with RMSE of 0.6120 mm s-1 for four clear-sky days in different growth stages. The estimates of half-hourly λET using the dual-source dual-leaf model (DSDL) agreed well with measurements and the error was within 5% during two growing seasons of maize with differing hydrometeorological and management strategies. Moreover, the estimates of soil evaporation using the DSDL model closely matched actual measurements. Our results indicate that the DSDL model can produce more accurate estimation of Gsc and λET, compared to the big-leaf model, and thus is an effective alternative approach for estimating and partitioning λET.

  13. Scaling up stomatal conductance from leaf to canopy using a dual-leaf model for estimating crop evapotranspiration.

    Directory of Open Access Journals (Sweden)

    Risheng Ding

    Full Text Available The dual-source Shuttleworth-Wallace model has been widely used to estimate and partition crop evapotranspiration (λET. Canopy stomatal conductance (Gsc, an essential parameter of the model, is often calculated by scaling up leaf stomatal conductance, considering the canopy as one single leaf in a so-called "big-leaf" model. However, Gsc can be overestimated or underestimated depending on leaf area index level in the big-leaf model, due to a non-linear stomatal response to light. A dual-leaf model, scaling up Gsc from leaf to canopy, was developed in this study. The non-linear stomata-light relationship was incorporated by dividing the canopy into sunlit and shaded fractions and calculating each fraction separately according to absorbed irradiances. The model includes: (1 the absorbed irradiance, determined by separately integrating the sunlit and shaded leaves with consideration of both beam and diffuse radiation; (2 leaf area for the sunlit and shaded fractions; and (3 a leaf conductance model that accounts for the response of stomata to PAR, vapor pressure deficit and available soil water. In contrast to the significant errors of Gsc in the big-leaf model, the predicted Gsc using the dual-leaf model had a high degree of data-model agreement; the slope of the linear regression between daytime predictions and measurements was 1.01 (R2 = 0.98, with RMSE of 0.6120 mm s-1 for four clear-sky days in different growth stages. The estimates of half-hourly λET using the dual-source dual-leaf model (DSDL agreed well with measurements and the error was within 5% during two growing seasons of maize with differing hydrometeorological and management strategies. Moreover, the estimates of soil evaporation using the DSDL model closely matched actual measurements. Our results indicate that the DSDL model can produce more accurate estimation of Gsc and λET, compared to the big-leaf model, and thus is an effective alternative approach for estimating and

  14. ππ interaction in the Born approximation of the dual model with quantized slope of the Regge trajectories

    International Nuclear Information System (INIS)

    Antonov, E.N.; Kudryavtsev, V.A.; Lyakhov, K.B.

    1983-01-01

    The Born approximation for the ππ interaction is discussed in the framework of the recently proposed dual model with quantized slope of the Regge trajectories, the partial width of the low-lying resonances are calculated, and fulfillment of Adler's self-consistency condition is verified. The resulting spectrum and resonance widths are compared with those of the models of Lovelace and Shapiro and of Frampton and with the experimental data

  15. Interaction of ordinary Portland cement and Opalinus Clay: Dual porosity modelling compared to experimental data

    Science.gov (United States)

    Jenni, A.; Gimmi, T.; Alt-Epping, P.; Mäder, U.; Cloet, V.

    2017-06-01

    Interactions between concrete and clays are driven by the strong chemical gradients in pore water and involve mineral reactions in both materials. In the context of a radioactive waste repository, these reactions may influence safety-relevant clay properties such as swelling pressure, permeability or radionuclide retention. Interfaces between ordinary Portland cement and Opalinus Clay show weaker, but more extensive chemical disturbance compared to a contact between low-pH cement and Opalinus Clay. As a consequence of chemical reactions porosity changes occur at cement-clay interfaces. These changes are stronger and may lead to complete pore clogging in the case of low-pH cements. The prediction of pore clogging by reactive transport simulations is very sensitive to the magnitude of diffusive solute fluxes, cement clinker chemistry, and phase reaction kinetics. For instance, the consideration of anion-depleted porosity in clays substantially influences overall diffusion and pore clogging at interfaces. A new concept of dual porosity modelling approximating Donnan equilibrium is developed and applied to an ordinary Portland cement - Opalinus Clay interface. The model predictions are compared with data from the cement-clay interaction (CI) field experiment in the Mt Terri underground rock laboratory (Switzerland), which represent 5 y of interaction. The main observations such as the decalcification of the cement at the interface, the Mg enrichment in the clay detached from the interface, and the S enrichment in the cement detached from the interface, are qualitatively predicted by the new model approach. The model results reveal multiple coupled processes that create the observed features. The quantitative agreement of modelled and measured data can be improved if uncertainties of key input parameters (tortuosities, reaction kinetics, especially of clay minerals) can be reduced.

  16. Partitioning of Cotton Field Evapotranspiration under Mulched Drip Irrigation Based on a Dual Crop Coefficient Model

    Directory of Open Access Journals (Sweden)

    Fuqiang Tian

    2016-02-01

    Full Text Available Estimation of field crop evapotranspiration (ETc and its partitioning into evaporation and transpiration, are of great importance in hydrological modeling and agricultural water management. In this study, we used a dual crop coefficient model SIMDualKc to estimate the actual crop evapotranspiration (ETc act and the basal crop coefficients over a cotton field in Northwestern China. A two-year field experiment was implemented in the cotton field under mulched drip irrigation. The simulated ETc act is consistent with observed ETc act as derived based on the eddy covariance system in the field. Basal crop coefficients of cotton for the initial, mid-season, and end-season are 0.20, 0.90, and 0.50, respectively. The transpiration components of ETc  act are 96% (77% and 94% (74% in 2012 and 2013 with (without plastic mulch, respectively. The impact of plastic mulch cover on soil evaporation is significant during drip irrigation ranging from crop development stage to mid-season stage. The extent of the impact depends on the variation of soil moisture, available energy of the soil surface, and the growth of the cotton leaves. Our results show that the SIMDualKc is capable of providing accurate estimation of ETc act for cotton field under mulched drip irrigation, and could be used as a valuable tool to establish irrigation schedule for cotton fields in arid regions as Northwestern China.

  17. Tritium transport modeling at system level for the EUROfusion dual coolant lithium-lead breeding blanket

    Science.gov (United States)

    Urgorri, F. R.; Moreno, C.; Carella, E.; Rapisarda, D.; Fernández-Berceruelo, I.; Palermo, I.; Ibarra, A.

    2017-11-01

    The dual coolant lithium lead (DCLL) breeding blanket is one of the four breeder blanket concepts under consideration within the framework of EUROfusion consortium activities. The aim of this work is to develop a model that can dynamically track tritium concentrations and fluxes along each part of the DCLL blanket and the ancillary systems associated to it at any time. Because of tritium nature, the phenomena of diffusion, dissociation, recombination and solubilisation have been modeled in order to describe the interaction between the lead-lithium channels, the structural material, the flow channel inserts and the helium channels that are present in the breeding blanket. Results have been obtained for a pulsed generation scenario for DEMO. The tritium inventory in different parts of the blanket, the permeation rates from the breeder to the secondary coolant and the amount of tritium extracted from the lead-lithium loop have been computed. Results present an oscillating behavior around mean values. The obtained average permeation rate from the liquid metal to the helium is 1.66 mg h-1 while the mean tritium inventory in the whole system is 417 mg. Besides the reference case results, parametric studies of the lead-lithium mass flow rate, the tritium extraction efficiency and the tritium solubility in lead-lithium have been performed showing the reaction of the system to the variation of these parameters.

  18. Study on Complex Advertising and Price Competition Dual-Channel Supply Chain Models Considering the Overconfidence Manufacturer

    Directory of Open Access Journals (Sweden)

    Junhai Ma

    2016-01-01

    Full Text Available In order to explore how the manufacturers make decisions when two manufacturers compete for local advertising investment, we examine two noncooperative models (Stackelberg and Nash game and propose a cost sharing contract to investigate channel competition of dual-channel supply chain. The dominant power between manufacturer and retailer and the effect of channel competition strategy on price are mainly discussed. In addition, dynamic system concepts are integrated into Stackelberg game model based on bounded rational mechanism. We analyze the local stability and find that the stability level of the dual-channel supply chains depends crucially on the price adjustment speed, the level of demand uncertainty, and the risk preference. The outcome shows that, under the master-slave game model, the profits of manufacturers are greater than that under decentralized decision-making mode, and the profits of retailers under master-slave game model are less than that under decentralized decision-making mode. The profits of manufacturers and retailers in the stable region are greater than that in unstable region. Finally, the delay feedback control method is utilized and effectively controls the chaotic behavior of dual-channel supply chain model. The results have theoretical and practical significance for the game models in terms of advertising and price competition.

  19. What makes us think? A three-stage dual-process model of analytic engagement.

    Science.gov (United States)

    Pennycook, Gordon; Fugelsang, Jonathan A; Koehler, Derek J

    2015-08-01

    The distinction between intuitive and analytic thinking is common in psychology. However, while often being quite clear on the characteristics of the two processes ('Type 1' processes are fast, autonomous, intuitive, etc. and 'Type 2' processes are slow, deliberative, analytic, etc.), dual-process theorists have been heavily criticized for being unclear on the factors that determine when an individual will think analytically or rely on their intuition. We address this issue by introducing a three-stage model that elucidates the bottom-up factors that cause individuals to engage Type 2 processing. According to the model, multiple Type 1 processes may be cued by a stimulus (Stage 1), leading to the potential for conflict detection (Stage 2). If successful, conflict detection leads to Type 2 processing (Stage 3), which may take the form of rationalization (i.e., the Type 1 output is verified post hoc) or decoupling (i.e., the Type 1 output is falsified). We tested key aspects of the model using a novel base-rate task where stereotypes and base-rate probabilities cued the same (non-conflict problems) or different (conflict problems) responses about group membership. Our results support two key predictions derived from the model: (1) conflict detection and decoupling are dissociable sources of Type 2 processing and (2) conflict detection sometimes fails. We argue that considering the potential stages of reasoning allows us to distinguish early (conflict detection) and late (decoupling) sources of analytic thought. Errors may occur at both stages and, as a consequence, bias arises from both conflict monitoring and decoupling failures. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Dual-Source Linear Energy Prediction (LINE-P) Model in the Context of WSNs.

    Science.gov (United States)

    Ahmed, Faisal; Tamberg, Gert; Le Moullec, Yannick; Annus, Paul

    2017-07-20

    Energy harvesting technologies such as miniature power solar panels and micro wind turbines are increasingly used to help power wireless sensor network nodes. However, a major drawback of energy harvesting is its varying and intermittent characteristic, which can negatively affect the quality of service. This calls for careful design and operation of the nodes, possibly by means of, e.g., dynamic duty cycling and/or dynamic frequency and voltage scaling. In this context, various energy prediction models have been proposed in the literature; however, they are typically compute-intensive or only suitable for a single type of energy source. In this paper, we propose Linear Energy Prediction "LINE-P", a lightweight, yet relatively accurate model based on approximation and sampling theory; LINE-P is suitable for dual-source energy harvesting. Simulations and comparisons against existing similar models have been conducted with low and medium resolutions (i.e., 60 and 22 min intervals/24 h) for the solar energy source (low variations) and with high resolutions (15 min intervals/24 h) for the wind energy source. The results show that the accuracy of the solar-based and wind-based predictions is up to approximately 98% and 96%, respectively, while requiring a lower complexity and memory than the other models. For the cases where LINE-P's accuracy is lower than that of other approaches, it still has the advantage of lower computing requirements, making it more suitable for embedded implementation, e.g., in wireless sensor network coordinator nodes or gateways.

  1. Uncovering molecular events associated with the chemosuppressive effects of flaxseed: a microarray analysis of the laying hen model of ovarian cancer.

    Science.gov (United States)

    Hales, Karen H; Speckman, Sheree C; Kurrey, Nawneet K; Hales, Dale B

    2014-08-24

    The laying hen model of spontaneous epithelial ovarian cancer (EOC) is unique in that it is the only model that enables observations of early events in disease progression and is therefore also uniquely suited for chemoprevention trials. Previous studies on the effect of dietary flaxseed in laying hens have revealed the potential for both amelioration and prevention of ovarian cancer. The objective of this study was to assess the effect of flaxseed on genes and pathways that are dysregulated in tumors. We have used a bioinformatics approach to identify these genes, followed by qPCR validation, immunohistochemical localization, and in situ hybridization to visualize expression in normal ovaries and tumors from animals fed a control diet or a diet containing 10% flaxseed. Bioinformatic analysis of ovarian tumors in hens led to the identification of a group of highly up-regulated genes that are involved in the embryonic process of branching morphogenesis. Expression of these genes coincides with expression of E-cadherin in the tumor epithelium. Levels of expression of these genes in tumors from flax-fed animals are reduced 40-60%. E-cadherin and miR200 are both up-regulated in tumors from control-fed hens, whereas their expression is decreased 60-75% in tumors from flax-fed hens. This does not appear to be due to an increase in ZEB1 as mRNA levels are increased five-fold in tumors, with no significant difference between control-fed and flax-fed hens. We suggest that nutritional intervention with flaxseed targets the pathways regulating branching morphogenesis and thereby alters the progression of ovarian cancer.

  2. Inverse modeling of rainfall infiltration with a dual permeability approach using different matrix-fracture coupling variants.

    Science.gov (United States)

    Blöcher, Johanna; Kuraz, Michal

    2017-04-01

    In this contribution we propose implementations of the dual permeability model with different inter-domain exchange descriptions and metaheuristic optimization algorithms for parameter identification and mesh optimization. We compare variants of the coupling term with different numbers of parameters to test if a reduction of parameters is feasible. This can reduce parameter uncertainty in inverse modeling, but also allow for different conceptual models of the domain and matrix coupling. The different variants of the dual permeability model are implemented in the open-source objective library DRUtES written in FORTRAN 2003/2008 in 1D and 2D. For parameter identification we use adaptations of the particle swarm optimization (PSO) and Teaching-learning-based optimization (TLBO), which are population-based metaheuristics with different learning strategies. These are high-level stochastic-based search algorithms that don't require gradient information or a convex search space. Despite increasing computing power and parallel processing, an overly fine mesh is not feasible for parameter identification. This creates the need to find a mesh that optimizes both accuracy and simulation time. We use a bi-objective PSO algorithm to generate a Pareto front of optimal meshes to account for both objectives. The dual permeability model and the optimization algorithms were tested on virtual data and field TDR sensor readings. The TDR sensor readings showed a very steep increase during rapid rainfall events and a subsequent steep decrease. This was theorized to be an effect of artificial macroporous envelopes surrounding TDR sensors creating an anomalous region with distinct local soil hydraulic properties. One of our objectives is to test how well the dual permeability model can describe this infiltration behavior and what coupling term would be most suitable.

  3. Z flux-line lattices and self-dual equations in the standard model

    International Nuclear Information System (INIS)

    Bimonte, G.; Lozano, G.

    1994-04-01

    We derive gauge covariant self-dual equations for the SU(2) x U(1) y theory of electroweak interactions and show that they admit solutions describing a periodic lattice of Z-strings. (author). 14 refs

  4. Computational Models for the Effects of Localized Sound Cuing in a Complex Dual Task

    National Research Council Canada - National Science Library

    Kieras, David

    2001-01-01

    ... cue in a visually-presented dual task setting that demonstrated an 'automation deficit' effect, This effect is temporarily impaired performance when an automated task must be resumed by the human operator...

  5. Uncovering the Driving Factors of Carbon Emissions in an Investment Allocation Model of China’s High-Carbon and Low-Carbon Energy

    Directory of Open Access Journals (Sweden)

    Shumin Jiang

    2017-06-01

    Full Text Available In the view of long-term comprehensive development, the concept of low-carbon economy has long been a concern. In this paper, we build a pure energy-economic system and explore the exact influencing factors in the investment allocation of high-carbon and low-carbon energy with the purpose of mitigating carbon dioxide in the atmosphere. The dynamic analysis shows that the model that we built is applicable for the current market situation and the way we adjust the investments of high-carbon and low-carbon energy are conductive to carbon abatement in the atmosphere. On the basis of the stability analysis and numerical simulation, some strategies are given to decrease the carbon dioxide in the atmosphere. The results show that the social consumption and public consumption behavior are the most important factors responsible for the variation in the atmospheric carbon dioxide. The cleanliness of high carbon presents an obvious mitigating effect on carbon in the atmosphere and the effect of marginal profit of high-carbon energy is the weakest. In addition, enhancing marginal profit, return on investment and investment share of low-carbon energy are beneficial to reduce carbon dioxide in the atmosphere, while a return on investment of high-carbon energy increasing is the detriment of the carbon dioxide in the atmosphere. Finally, we provide carbon mitigation effort by considering both economic development and carbon abatement for policymakers to achieve a desirable emission-reduction effect.

  6. Dual Binding Site and Selective Acetylcholinesterase Inhibitors Derived from Integrated Pharmacophore Models and Sequential Virtual Screening

    Directory of Open Access Journals (Sweden)

    Shikhar Gupta

    2014-01-01

    Full Text Available In this study, we have employed in silico methodology combining double pharmacophore based screening, molecular docking, and ADME/T filtering to identify dual binding site acetylcholinesterase inhibitors that can preferentially inhibit acetylcholinesterase and simultaneously inhibit the butyrylcholinesterase also but in the lesser extent than acetylcholinesterase. 3D-pharmacophore models of AChE and BuChE enzyme inhibitors have been developed from xanthostigmine derivatives through HypoGen and validated using test set, Fischer’s randomization technique. The best acetylcholinesterase and butyrylcholinesterase inhibitors pharmacophore hypotheses Hypo1_A and Hypo1_B, with high correlation coefficient of 0.96 and 0.94, respectively, were used as 3D query for screening the Zinc database. The screened hits were then subjected to the ADME/T and molecular docking study to prioritise the compounds. Finally, 18 compounds were identified as potential leads against AChE enzyme, showing good predicted activities and promising ADME/T properties.

  7. Dual-Model Reverse CKF Algorithm in Cooperative Navigation for USV

    Directory of Open Access Journals (Sweden)

    Bo Xu

    2014-01-01

    Full Text Available As one of the most promising research directions, cooperative location with high precision and low-cost IMU is becoming an emerging research topic in many positioning fields. Low-cost MEMS/DVL is a preferred solution for dead-reckoning in multi-USV cooperative network. However, large misalignment angles and large gyro drift coexist in low-cost MEMS that leads to the poor observability. Based on cubature Kalman filter (CKF algorithm that has access to high accuracy and relative small computation, dual-model filtering scheme is proposed. It divides the whole process into two subsections that cut off the coupling relations and improve the observability of MEMS errors: it first estimates large misalignment angle and then estimates the gyro drift. Furthermore, to improve the convergence speed of large misalignment angle estimated in the first subsection, “time reversion” concept is introduced. It uses a short period time to forward and backward several times to improve convergence speed effectively. Finally, simulation analysis and experimental verification is conducted. Simulation and experimental results show that the algorithm can effectively improve the cooperative navigation performance.

  8. Formulaic language in cortical and subcortical disease: Evidence of the dual process model.

    Directory of Open Access Journals (Sweden)

    Kelly Bridges

    2014-04-01

    Full Text Available Introduction: It is known that an intact cortical left hemisphere is crucial for language production. Recently, more credit is given to the right hemisphere and subcortical areas in the production of non-novel language, including formulaic language. John Hughlings Jackson (1874/1958, first described how propositional and non-propositional speech are differentially affected by neural impairment. Non-propositional language is often preserved following left hemisphere stroke even when aphasia is present (Code, 1982; Sidtis et al., 2009; Van Lancker Sidtis & Postman, 2006. With right hemisphere and subcortical stroke, formulaic language is reduced (Sidtis et al., 2009; Van Lancker Sidtis & Postman, 2006; Speedie et al., 1993. The dual process model of language competence states that propositional and non-propositional speech are processed differently in the brain, with novel speech controlled by the left hemisphere, and a right hemisphere/subcortical circuit modulating formulaic language (Van Lancker Sidtis, 2004; 2012. Two studies of formulaic language will be presented as further evidence of the dual process model: a study of formulaic language in Alzheimer’s disease, and a study of recited speech in Parkinson’s disease. Formulaic language includes overlearned words, phrases or longer linguistic units that are known to the native speaker, occur naturally in discourse, and are important for normal social interaction (Fillmore, 1979; Pawley & Syder, 1983; Van Lancker, 1988; Van Lancker Sidtis, 2004; Wray, 2002. Formulaic expressions include conversational speech formulas, idioms, proverbs, expletives, pause fillers, discourse elements, and sentence stems (stereotyped sentence-initials. Longer units of linguistic material, such as prayers, rhymes, and poems, termed recited speech, is another subtype of formulaic language that is learned in childhood and recited periodically throughout life. Cortical disease: Alzheimer’s disease and formulaic

  9. Modeling Psychological Contract Violation using Dual Regime Models: An Event-based Approach

    Directory of Open Access Journals (Sweden)

    Joeri Hofmans

    2017-11-01

    Full Text Available A good understanding of the dynamics of psychological contract violation requires theories, research methods and statistical models that explicitly recognize that violation feelings follow from an event that violates one's acceptance limits, after which interpretative processes are set into motion, determining the intensity of these violation feelings. Whereas theories—in the form of the dynamic model of the psychological contract—and research methods—in the form of daily diary research and experience sampling research—are available by now, the statistical tools to model such a two-stage process are still lacking. The aim of the present paper is to fill this gap in the literature by introducing two statistical models—the Zero-Inflated model and the Hurdle model—that closely mimic the theoretical process underlying the elicitation violation feelings via two model components: a binary distribution that models whether violation has occurred or not, and a count distribution that models how severe the negative impact is. Moreover, covariates can be included for both model components separately, which yields insight into their unique and shared antecedents. By doing this, the present paper offers a methodological-substantive synergy, showing how sophisticated methodology can be used to examine an important substantive issue.

  10. A Homogeneous and Self-Dual Interior-Point Linear Programming Algorithm for Economic Model Predictive Control

    DEFF Research Database (Denmark)

    Sokoler, Leo Emil; Frison, Gianluca; Skajaa, Anders

    2015-01-01

    We develop an efficient homogeneous and self-dual interior-point method (IPM) for the linear programs arising in economic model predictive control of constrained linear systems with linear objective functions. The algorithm is based on a Riccati iteration procedure, which is adapted to the linear...... is significantly faster than several state-of-the-art IPMs based on sparse linear algebra, and 2) warm-start reduces the average number of iterations by 35-40%.......We develop an efficient homogeneous and self-dual interior-point method (IPM) for the linear programs arising in economic model predictive control of constrained linear systems with linear objective functions. The algorithm is based on a Riccati iteration procedure, which is adapted to the linear...

  11. Statistical Model-Based Voice Activity Detection Using Spatial Cues and Log Energy for Dual-Channel Noisy Speech Recognition

    Science.gov (United States)

    Park, Ji Hun; Shin, Min Hwa; Kim, Hong Kook

    In this paper, a voice activity detection (VAD) method for dual-channel noisy speech recognition is proposed on the basis of statistical models constructed by spatial cues and log energy. In particular, spatial cues are composed of the interaural time differences and interaural level differences of dual-channel speech signals, and the statistical models for speech presence and absence are based on a Gaussian kernel density. In order to evaluate the performance of the proposed VAD method, speech recognition is performed using only speech signals segmented by the proposed VAD method. The performance of the proposed VAD method is then compared with those of conventional methods such as a signal-to-noise ratio variance based method and a phase vector based method. It is shown from the experiments that the proposed VAD method outperforms conventional methods, providing the relative word error rate reductions of 19.5% and 12.2%, respectively.

  12. Dual-use tools and systematics-aware analysis workflows in the ATLAS Run-2 analysis model

    CERN Document Server

    FARRELL, Steven; The ATLAS collaboration; Calafiura, Paolo; Delsart, Pierre-Antoine; Elsing, Markus; Koeneke, Karsten; Krasznahorkay, Attila; Krumnack, Nils; Lancon, Eric; Lavrijsen, Wim; Laycock, Paul; Lei, Xiaowen; Strandberg, Sara Kristina; Verkerke, Wouter; Vivarelli, Iacopo; Woudstra, Martin

    2015-01-01

    The ATLAS analysis model has been overhauled for the upcoming run of data collection in 2015 at 13 TeV. One key component of this upgrade was the Event Data Model (EDM), which now allows for greater flexibility in the choice of analysis software framework and provides powerful new features that can be exploited by analysis software tools. A second key component of the upgrade is the introduction of a dual-use tool technology, which provides abstract interfaces for analysis software tools to run in either the Athena framework or a ROOT-based framework. The tool interfaces, including a new interface for handling systematic uncertainties, have been standardized for the development of improved analysis workflows and consolidation of high-level analysis tools. This paper will cover the details of the dual-use tool functionality, the systematics interface, and how these features fit into a centrally supported analysis environment.

  13. Dual-use tools and systematics-aware analysis workflows in the ATLAS Run-II analysis model

    CERN Document Server

    FARRELL, Steven; The ATLAS collaboration

    2015-01-01

    The ATLAS analysis model has been overhauled for the upcoming run of data collection in 2015 at 13 TeV. One key component of this upgrade was the Event Data Model (EDM), which now allows for greater flexibility in the choice of analysis software framework and provides powerful new features that can be exploited by analysis software tools. A second key component of the upgrade is the introduction of a dual-use tool technology, which provides abstract interfaces for analysis software tools to run in either the Athena framework or a ROOT-based framework. The tool interfaces, including a new interface for handling systematic uncertainties, have been standardized for the development of improved analysis workflows and consolidation of high-level analysis tools. This presentation will cover the details of the dual-use tool functionality, the systematics interface, and how these features fit into a centrally supported analysis environment.

  14. Desired lifetime and end-of-life desires across adulthood from 20 to 90: a dual-source information model.

    Science.gov (United States)

    Lang, Frieder R; Baltes, Paul B; Wagner, Gert G

    2007-09-01

    How long do people want to live, and how does scientific research on aging affect such desires? A dual-source information model proposes that aging expectations and desires are informed differently by two sources: personal experiences on the one hand, and scientific and societal influences on the other. Two studies with independent German national samples explored desires regarding length of life and end of life among adults between the ages of 20 and 90. FINDINGS ARE: First, desired lifetime is consistent at around 85 years with few age differences. Second, experimental induction of good or bad news from research on aging has little effect in Study 1. Third, interest in science has moderating effects on desired lifetime in Study 2. Fourth, there is a high prevalence of a strong desire to control the "when and how" of one's death, although only 11% of the individuals completed a living will. Findings are consistent with the dual-source information model.

  15. Beyond single syllables: large-scale modeling of reading aloud with the Connectionist Dual Process (CDP++) model.

    Science.gov (United States)

    Perry, Conrad; Ziegler, Johannes C; Zorzi, Marco

    2010-09-01

    Most words in English have more than one syllable, yet the most influential computational models of reading aloud are restricted to processing monosyllabic words. Here, we present CDP++, a new version of the Connectionist Dual Process model (Perry, Ziegler, & Zorzi, 2007). CDP++ is able to simulate the reading aloud of mono- and disyllabic words and nonwords, and learns to assign stress in exactly the same way as it learns to associate graphemes with phonemes. CDP++ is able to simulate the monosyllabic benchmark effects its predecessor could, and therefore shows full backwards compatibility. CDP++ also accounts for a number of novel effects specific to disyllabic words, including the effects of stress regularity and syllable number. In terms of database performance, CDP++ accounts for over 49% of the reaction time variance on items selected from the English Lexicon Project, a very large database of several thousand of words. With its lexicon of over 32,000 words, CDP++ is therefore a notable example of the successful scaling-up of a connectionist model to a size that more realistically approximates the human lexical system. Copyright © 2010 Elsevier Inc. All rights reserved.

  16. A dual process model of diversity outcomes: The case of the South African Police Service in the Pretoria area

    OpenAIRE

    Jackson, L.T.B.; van de Vijver, F.J.R.; Molokoane, D.H.

    2013-01-01

    Orientation: The study addresses the question of how employees of the South African Police Service (SAPS) cope with intercultural relations in an increasingly diverse organisation. Research purpose: A dual-process model of diversity outcomes was tested in which a distinction is made between a positive (work-related) stream that links positive diversity conditions through active coping to work outcomes and a relatively independent health related) stream of negative antecedents, mediating passi...

  17. A dual-process model of diversity outcomes: The case South African police service in the Pretoria area

    OpenAIRE

    Leon T.B. Jackson; Fons J.R. van de Vijver; Davey H. Molokoane

    2013-01-01

    Orientation: The study addresses the question of how employees of the South African Police Service (SAPS) cope with intercultural relations in an increasingly diverse organisation.Research purpose: A dual-process model of diversity outcomes was tested in which a distinction is made between a positive (work-related) stream that links positive diversity conditions through active coping to work outcomes and a relatively independent health related) stream of negative antecedents, mediating passiv...

  18. Acting in solidarity: testing an extended dual-pathway model of collective action by bystander group members

    OpenAIRE

    Saab, Rim; Tausch, Nicole; Spears, Russell; Cheung, Wing

    2015-01-01

    We examined predictors of collective action among bystander group members in solidarity with a disadvantaged group by extending the dual pathway model of collective action, which proposes one efficacy-based and one emotion-based path to collective action (van Zomeren, Spears, Fischer, & Leach, 2004). Based on two proposed functions of social identity performance (Klein, Spears, & Reicher, 2007), we distinguished between the efficacy of collective action at consolidating the identity of a prot...

  19. A Study of Problems and Responses in the Development of Dual-Language Education Models in Tibetan Regions: Taking Xiahe County in Gannan Tibetan Autonomous Prefecture as an Example

    Science.gov (United States)

    Hongzhi, Long

    2017-01-01

    Dual-language education models are theoretical and practical systems formed through the process of dual-language education and centered on study and teaching. The language environment is the basis for developing and reforming dual-language education models. The author takes Xiahe County in Gannan Tibetan Autonomous Prefecture as an example and…

  20. Modeling healthcare authorization and claim submissions using the openEHR dual-model approach

    Science.gov (United States)

    2011-01-01

    Background The TISS standard is a set of mandatory forms and electronic messages for healthcare authorization and claim submissions among healthcare plans and providers in Brazil. It is not based on formal models as the new generation of health informatics standards suggests. The objective of this paper is to model the TISS in terms of the openEHR archetype-based approach and integrate it into a patient-centered EHR architecture. Methods Three approaches were adopted to model TISS. In the first approach, a set of archetypes was designed using ENTRY subclasses. In the second one, a set of archetypes was designed using exclusively ADMIN_ENTRY and CLUSTERs as their root classes. In the third approach, the openEHR ADMIN_ENTRY is extended with classes designed for authorization and claim submissions, and an ISM_TRANSITION attribute is added to the COMPOSITION class. Another set of archetypes was designed based on this model. For all three approaches, templates were designed to represent the TISS forms. Results The archetypes based on the openEHR RM (Reference Model) can represent all TISS data structures. The extended model adds subclasses and an attribute to the COMPOSITION class to represent information on authorization and claim submissions. The archetypes based on all three approaches have similar structures, although rooted in different classes. The extended openEHR RM model is more semantically aligned with the concepts involved in a claim submission, but may disrupt interoperability with other systems and the current tools must be adapted to deal with it. Conclusions Modeling the TISS standard by means of the openEHR approach makes it aligned with ISO recommendations and provides a solid foundation on which the TISS can evolve. Although there are few administrative archetypes available, the openEHR RM is expressive enough to represent the TISS standard. This paper focuses on the TISS but its results may be extended to other billing processes. A complete

  1. Modeling healthcare authorization and claim submissions using the openEHR dual-model approach

    Directory of Open Access Journals (Sweden)

    Freire Sergio M

    2011-10-01

    Full Text Available Abstract Background The TISS standard is a set of mandatory forms and electronic messages for healthcare authorization and claim submissions among healthcare plans and providers in Brazil. It is not based on formal models as the new generation of health informatics standards suggests. The objective of this paper is to model the TISS in terms of the openEHR archetype-based approach and integrate it into a patient-centered EHR architecture. Methods Three approaches were adopted to model TISS. In the first approach, a set of archetypes was designed using ENTRY subclasses. In the second one, a set of archetypes was designed using exclusively ADMIN_ENTRY and CLUSTERs as their root classes. In the third approach, the openEHR ADMIN_ENTRY is extended with classes designed for authorization and claim submissions, and an ISM_TRANSITION attribute is added to the COMPOSITION class. Another set of archetypes was designed based on this model. For all three approaches, templates were designed to represent the TISS forms. Results The archetypes based on the openEHR RM (Reference Model can represent all TISS data structures. The extended model adds subclasses and an attribute to the COMPOSITION class to represent information on authorization and claim submissions. The archetypes based on all three approaches have similar structures, although rooted in different classes. The extended openEHR RM model is more semantically aligned with the concepts involved in a claim submission, but may disrupt interoperability with other systems and the current tools must be adapted to deal with it. Conclusions Modeling the TISS standard by means of the openEHR approach makes it aligned with ISO recommendations and provides a solid foundation on which the TISS can evolve. Although there are few administrative archetypes available, the openEHR RM is expressive enough to represent the TISS standard. This paper focuses on the TISS but its results may be extended to other billing

  2. Dual Diagnosis

    Science.gov (United States)

    A person with dual diagnosis has both a mental disorder and an alcohol or drug problem. These conditions occur together frequently. In particular, ... to emotional and mental problems. Someone with a dual diagnosis must treat both conditions. For the treatment ...

  3. Thermodynamic modeling of protein retention in mixed-mode chromatography: An extended model for isocratic and dual gradient elution chromatography.

    Science.gov (United States)

    Lee, Yi Feng; Graalfs, Heiner; Frech, Christian

    2016-09-16

    An extended model is developed to describe protein retention in mixed-mode chromatography based on thermodynamic principles. Special features are the incorporation of pH dependence of the ionic interaction on a mixed-mode resin and the addition of a water term into the model which enables one to describe the total number of water molecules released at the hydrophobic interfaces upon protein-ligand binding. Examples are presented on how to determine the model parameters using isocratic elution chromatography. Four mixed-mode anion-exchanger prototype resins with different surface chemistries and ligand densities were tested using isocratic elution of two monoclonal antibodies at different pH values (7-10) and encompassed a wide range of NaCl concentrations (0-5M). U-shape mixed-mode retention curves were observed for all four resins. By taking into account of the deprotonation and protonation of the weak cationic functional groups in these mixed-mode anion-exchanger prototype resins, conditions which favor protein-ligand binding via mixed-mode strong cationic ligands as well as conditions which favor protein-ligand binding via both mixed-mode strong cationic ligands and non-hydrophobic weak cationic ligands were identified. The changes in the retention curves with pH, salt, protein, and ligand can be described very well by the extended model using meaningful thermodynamic parameters like Gibbs energy, number of ionic and hydrophobic interactions, total number of released water molecules as well as modulator interaction constant. Furthermore, the fitted model parameters based on isocratic elution data can also be used to predict protein retention in dual salt-pH gradient elution chromatography. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Hydroclimatology of Dual Peak Cholera Incidence in Bengal Region: Inferences from a Spatial Explicit Model

    Science.gov (United States)

    Bertuzzo, E.; Mari, L.; Righetto, L.; Casagrandi, R.; Gatto, M.; Rodriguez-Iturbe, I.; Rinaldo, A.

    2010-12-01

    by a spring peak confined to the coastal area and a autumn peak involving the whole region. The modeling exercise allows to identify the relevant processes and to understand how they concert to the generation of this peculiar pattern. Finally, the range of epidemiological and hydrological conditions under which dual or a single peaks are expected is quantified.

  5. Modeling and Control of Fuel Distribution in a Dual-Fuel Internal Combustion Engine Leveraging Late Intake Valve Closings

    Energy Technology Data Exchange (ETDEWEB)

    Kassa, Mateos; Hall, Carrie; Ickes, Andrew; Wallner, Thomas

    2017-10-01

    Advanced internal combustion engines, although generally more efficient than conventional combustion engines, often encounter limitations in multi-cylinder applications due to variations in the combustion process encountered across cylinders and between cycles. This study leverages experimental data from an inline 6-cylinder heavy-duty dual fuel engine equipped with exhaust gas recirculation (EGR), a variable geometry turbocharger, and a fully-flexible variable intake valve actuation system to study cylinder-to-cylinder variations in power production and the underlying uneven fuel distribution that causes these variations. The engine is operated with late intake valve closure timings in a dual-fuel combustion mode in which a high reactivity fuel is directly injected into the cylinders and a low reactivity fuel is port injected into the cylinders. Both dual fuel implementation and late intake valve closing (IVC) timings have been shown to improve thermal efficiency. However, experimental data from this study reveal that when late IVC timings are used on a multi-cylinder dual fuel engine a significant variation in IMEP across cylinders results and as such, leads to efficiency losses. The difference in IMEP between the different cylinders ranges from 9% at an IVC of 570°ATDC to 38% at an IVC of 610°ATDC and indicates an increasingly uneven fuel distribution. These experimental observations along with engine simulation models developed using GT-Power have been used to better understand the distribution of the port injected fuel across cylinders under various operating conditions on such dual fuel engines. This study revealed that the fuel distribution across cylinders in this dual fuel application is significantly affected by changes in the effective compression ratio as determined by the intake valve close timing as well as the design of the intake system (specifically the length of the intake runners). Late intake valve closures allow a portion of the trapped air

  6. Vocational Dual Education System: comparison between the German model and the new Spanish vocational training

    Directory of Open Access Journals (Sweden)

    Laura Rego Agraso

    2015-06-01

    Full Text Available The German dual system of vocational training has been object of transfer in some countries all over the world, among them Spain. Indeed, in this article we try to clarify the key elements in the adapting process of this Dual System to our country, analyzing its chances of success. To do this, we contribute a descriptive study of the main elements of the German Dual System. Then, the focus will be in the changes in our country, from the LOMCE project to the legislation governing apprenticeship and training. As a kind of discussion, we pretend to clarify how cultural and organizational elements of the production system have a strongly influence in the chances of success on the Vocational Training reform policy initiatives. Finally, we completed a series of proposals for action that would contribute to the employment and an increase in the qualification among Spanish young people.

  7. Examination of a dual-process model predicting riding with drinking drivers.

    Science.gov (United States)

    Hultgren, Brittney A; Scaglione, Nichole M; Cleveland, Michael J; Turrisi, Rob

    2015-06-01

    Nearly 1 in 5 of the fatalities in alcohol-related crashes are passengers. Few studies have utilized theory to examine modifiable psychosocial predictors of individuals' tendencies to be a passenger in a vehicle operated by a driver who has consumed alcohol. This study used a prospective design to test a dual-process model featuring reasoned and reactive psychological influences and psychosocial constructs as predictors of riding with drinking drivers (RWDD) in a sample of individuals aged 18 to 21. College students (N = 508) completed web-based questionnaires assessing RWDD, psychosocial constructs (attitudes, expectancies, and norms), and reasoned and reactive influences (intentions and willingness) at baseline (the middle of the spring semester) and again 1 and 6 months later. Regression was used to analyze reasoned and reactive influences as proximal predictors of RWDD at the 6-month follow-up. Subsequent analyses examined the relationship between the psychosocial constructs as distal predictors of RWDD and the mediation effects of reasoned and reactive influences. Both reasoned and reactive influences predicted RWDD, while only the reactive influence had a significant unique effect. Reactive influences significantly mediated the effects of peer norms, attitudes, and drinking influences on RWDD. Nearly all effects were constant across gender except parental norms (significant for females). Findings highlight that the important precursors of RWDD were reactive influences, attitudes, and peer and parent norms. These findings suggest several intervention methods, specifically normative feedback interventions, parent-based interventions, and brief motivational interviewing, may be particularly beneficial in reducing RWDD. Copyright © 2015 by the Research Society on Alcoholism.

  8. Modelling an advanced ManPAD with dual band detectors and a rosette scanning seeker head

    Science.gov (United States)

    Birchenall, Richard P.; Richardson, Mark A.; Butters, Brian; Walmsley, Roy

    2012-01-01

    Man Portable Air Defence Systems (ManPADs) have been a favoured anti aircraft weapon since their appearance on the military proliferation scene in the mid 1960s. Since this introduction there has been a 'cat and mouse' game of Missile Countermeasures (CMs) and the aircraft protection counter counter measures (CCMs) as missile designers attempt to defeat the aircraft platform protection equipment. Magnesium Teflon Viton (MTV) flares protected the target aircraft until the missile engineers discovered the art of flare rejection using techniques including track memory and track angle bias. These early CCMs relied upon CCM triggering techniques such as the rise rate method which would just sense a sudden increase in target energy and assume that a flare CM had been released by the target aircraft. This was not as reliable as was first thought as aspect changes (bringing another engine into the field of view) or glint from the sun could inadvertently trigger a CCM when not needed. The introduction of dual band detectors in the 1980s saw a major advance in CCM capability allowing comparisons between two distinct IR bands to be made thus allowing the recognition of an MTV flare to occur with minimal false alarms. The development of the rosette scan seeker in the 1980s complemented this advancement allowing the scene in the missile field of view (FOV) to be scanned by a much smaller (1/25) instantaneous FOV (IFOV) with the spectral comparisons being made at each scan point. This took the ManPAD from a basic IR energy detector to a pseudo imaging system capable of analysing individual elements of its overall FOV allowing more complex and robust CCM to be developed. This paper continues the work published in [1,2] and describes the method used to model an advanced ManPAD with a rosette scanning seeker head and robust CCMs similar to the Raytheon Stinger RMP.

  9. Pricing Models for Dual-channel Reverse Supply Chain Considering Regional Differences under “Internet Recycling” Mode in China

    Science.gov (United States)

    Wu, Di; Li, Peng; Chen, Juhong

    2018-01-01

    In recent years, the Internet technology has been deeply influencing recycling industry to make it more intelligent and interconnected. However, most existing papers on “Internet Recycling” neglected the problem of pricing strategy under online and offline channels for different levels of recyclers. Moreover, the effect of regional differences has been emphasized a lot in dual-channel forward supply chain, but recycling field has seldom been concerned about it. In this paper, a recycling system consisting of one recycling center and several third-party recyclers (TPR) was investigated based on traditional mode and dual-channel mode. The dual-channel reverse supply chain model is transformed from traditional mode by the introduction of online channel. It involves two recycling modes, as recycling centre for online recovery and “Recycling center+TPR” for offline recovery. By establishing pricing strategies based on Stackelberg game model, the impacts of regional differences were analysed. Finally, numerical analysis was given to illustrate the effectiveness of the pricing mechanisms and strategies.

  10. Dual Symmetry in Gauge Theories

    OpenAIRE

    Koshkarov, A. L.

    1997-01-01

    Continuous dual symmetry in electrodynamics, Yang-Mills theory and gravitation is investigated. Dual invariant which leads to badly nonlinear motion equations is chosen as a Lagrangian of the pure classical dual nonlinear electrodynamics. In a natural manner some dual angle which is determined by the electromagnetic strengths at the point of the time-space appears in the model. Motion equations may well be interpreted as the equations of the standard Maxwell theory with source. Alternative in...

  11. Gravity dual of two-dimensional N = (2, 2)∗ supersymmetric Yang-Mills theory and integrable models

    Science.gov (United States)

    Nian, Jun

    2018-03-01

    The 2D N = (2, 2)∗ supersymmetric Yang-Mills theory can be obtained from the 2D N = (4, 4) theory with a twisted mass deformation. In this paper we construct the gravity dual theory of the 2D N = (2, 2)∗ supersymmetric U( N ) Yang-Mills theory at the large N and large 't Hooft coupling limit using the 5D gauged supergravity. In the UV regime, this construction also provides the gravity dual of the 2D N = (2 , 2)∗ U( N ) topological Yang-Mills-Higgs theory. We propose a triality in the UV regime among integrable model, gauge theory and gravity, and we make some checks of this relation at classical level.

  12. A dual-porosity model for two-phase flow in deforming porous media

    Science.gov (United States)

    Shu, Zhengying

    Only recently has one realized the importance of the coupling of fluid flow with rock matrix deformations for accurately modeling many problems in petroleum, civil, environmental, geological and mining engineering. In the oil industry, problems such as reservoir compaction, ground subsidence, borehole stability and sanding need to be simulated using a coupled approach to make more precise predictions than when each process is considered to be independent of the other. Due to complications associated with multiple physical processes and mathematical representation of a multiphase now system in deformable fractured reservoirs, very few references, if any, are available in the literature. In this dissertation, an approach, which is based on the dual-porosity concept and takes into account rock deformations, is presented to derive rigorously a set of coupled differential equations governing the behavior of fractured porous media and two-phase fluid flow. The finite difference numerical method, as an alternative method for finite element, is applied to discretize the governing equations both in time and space domains. Throughout the derived set of equations, the fluid pressures and saturations as well as the solid displacements are considered as the primary unknowns. The model is tested against the case of single-phase flow in a 1-D consolidation problem for which analytical solutions are available. An example of coupled two-phase fluid flow and rock deformations for a scenario of a one-dimensional, fractured porous medium is also discussed. The numerical model and simulator, RFIA (Rock Fluid InterAction), developed in this dissertation can be a powerful tool to solve difficult problems not only in petroleum engineering such as ground subsidence, borehole stability and sand control, but also in civil engineering such as groundwater flow through fractured bedrock and in environmental engineering such as waste deposit concerns in fractured and unconsolidated formations

  13. Model-based crosstalk compensation for simultaneous 99mTc/123I dual-isotope brain SPECT imaging.

    Science.gov (United States)

    Du, Yong; Tsui, Benjamin M W; Frey, Eric C

    2007-09-01

    In this work, we developed a model-based method to estimate and compensate for the crosstalk contamination in simultaneous 123I and 99mTc dual isotope brain single photo emission computed tomography imaging. The model-based crosstalk compensation (MBCC) includes detailed modeling of photon interactions inside both the object and the detector system. In the method, scatter in the object is modeled using the effective source scatter estimation technique, including contributions from all the photon emissions. The effects of the collimator-detector response, including the penetration and scatter components due to high-energy 123I photons, are modeled using precalculated tables of Monte Carlo simulated point-source response functions obtained from sources in air at various distances from the face of the collimator. The model-based crosstalk estimation method was combined with iterative reconstruction based compensation to reduce contamination due to crosstalk. The MBCC method was evaluated using Monte Carlo simulated and physical phantom experimentally acquired simultaneous dual-isotope data. Results showed that, for both experimental and simulation studies, the model-based method provided crosstalk estimates that were in good agreement with the true crosstalk. Compensation using MBCC improved image contrast and removed the artifacts for both Monte Carlo simulated and experimentally acquired data. The results were in good agreement with images acquired without any crosstalk contamination.

  14. Model-based crosstalk compensation for simultaneous Tc99m∕I123 dual-isotope brain SPECT imaging.

    Science.gov (United States)

    Du, Yong; Tsui, Benjamin M W; Frey, Eric C

    2007-09-01

    In this work, we developed a model-based method to estimate and compensate for the crosstalk contamination in simultaneous I123 and Tc99m dual isotope brain single photo emission computed tomography imaging. The model-based crosstalk compensation (MBCC) includes detailed modeling of photon interactions inside both the object and the detector system. In the method, scatter in the object is modeled using the effective source scatter estimation technique, including contributions from all the photon emissions. The effects of the collimator-detector response, including the penetration and scatter components due to high-energy I123 photons, are modeled using pre-calculated tables of Monte Carlo simulated point-source response functions obtained from sources in air at various distances from the face of the collimator. The model-based crosstalk estimation method was combined with iterative reconstruction based compensation to reduce contamination due to crosstalk. The MBCC method was evaluated using Monte Carlo simulated and physical phantom experimentally acquired simultaneous dual-isotope data. Results showed that, for both experimental and simulation studies, the model-based method provided crosstalk estimates that were in good agreement with the true crosstalk. Compensation using MBCC improved image contrast and removed the artifacts for both Monte Carlo simulated and experimentally acquired data. The results were in good agreement with images acquired without any crosstalk contamination. © 2007 American Association of Physicists in Medicine.

  15. mathematical model of thermal explosion, the dual variational formulation of nonlinear problem, alternative functional

    Directory of Open Access Journals (Sweden)

    V. S. Zarubin

    2016-01-01

    in its plane, and in the circular cylinder unlimited in length.An approximate numerical solution of the differential equation that is included in a nonlinear mathematical model of the thermal explosion enables us to obtain quantitative estimates of combination of determining parameters at which the limit state occurs in areas of not only canonical form. A capability to study of the thermal explosion state can be extended in the context of development of mathematical modeling methods, including methods of model analysis to describe the thermal state of solids.To analyse a mathematical model of the thermal explosion in a homogeneous solid the paper uses a variational approach based on the dual variational formulation of the appropriate nonlinear stationary problem of heat conduction in such a body. This formulation contains two alternative functional reaching the matching values in their stationary points corresponding to the true temperature distribution. This functional feature allows you to not only get an approximate quantitative estimate of the combination of parameters that determine the thermal explosion state, but also to find the greatest possible error in such estimation.

  16. Un/covering: Making Disability Identity Legible

    Directory of Open Access Journals (Sweden)

    Heather Dawn Evans

    2017-03-01

    Full Text Available This article examines one aspect of disability identity among people with non-apparent or "invisible" disabilities: the decision to emphasize, remind others about, or openly acknowledge impairment in social settings. I call this process "un/covering," and situate this concept in the sociological and Disability Studies literature on disability stigma, passing, and covering. Drawing on interviews with people who have acquired a non-apparent impairment through chronic illness or injury, I argue that decisions to un/cover (after a disability disclosure has already been made play a pivotal role for this group in developing a strong, positive disability identity and making that identity legible to others. Decisions to pass, cover, or un/cover are ongoing decisions that stitch together the fabric of each person's daily life experiences, thus serving as primary mechanisms for identity negotiation and management.

  17. Unified analytical threshold voltage model for non-uniformly doped dual metal gate fully depleted silicon-on-insulator MOSFETs

    Science.gov (United States)

    Rao, Rathnamala; Katti, Guruprasad; Havaldar, Dnyanesh S.; DasGupta, Nandita; DasGupta, Amitava

    2009-03-01

    The paper describes the unified analytical threshold voltage model for non-uniformly doped, dual metal gate (DMG) fully depleted silicon-on-insulator (FDSOI) MOSFETs based on the solution of 2D Poisson's equation. 2D Poisson's equation is solved analytically for appropriate boundary conditions using separation of variables technique. The solution is then extended to obtain the threshold voltage of the FDSOI MOSFET. The model is able to handle any kind of non-uniform doping, viz. vertical, lateral as well as laterally asymetric channel (LAC) profile in the SOI film in addition to the DMG structure. The analytical results are validated with the numerical simulations using the device simulator MEDICI.

  18. The Conceptual Model of Future Teachers Training to Dual Education in VET (Vocational Education & Training)

    Science.gov (United States)

    Zholdasbekova, Saule; Nurzhanbayeva, Zhanat; Karatayev, Galymzhan; Akhmet, Laura Smatullaevna; Anarmetov, Bahitzhan

    2016-01-01

    In the article the author presents the theoretical understanding of research problems of training of the future teachers-organizers of the dual training system in vocational education & training (VET) in the conditions of the credit technology of education. The author's vision of way to solve the problem is discussed in the description of the…

  19. Dual Diathesis-Stressor Model of Emotional and Linguistic Contributions to Developmental Stuttering

    Science.gov (United States)

    Walden, Tedra A.; Frankel, Carl B.; Buhr, Anthony P.; Johnson, Kia N.; Conture, Edward G.; Karrass, Jan M.

    2012-01-01

    This study assessed emotional and speech-language contributions to childhood stuttering. A dual diathesis-stressor framework guided this study, in which both linguistic requirements and skills, and emotion and its regulation, are hypothesized to contribute to stuttering. The language diathesis consists of expressive and receptive language skills.…

  20. Dual Processes in Decision Making and Developmental Neuroscience: A Fuzzy-Trace Model

    Science.gov (United States)

    Reyna, Valerie F.; Brainerd, Charles J.

    2011-01-01

    From Piaget to the present, traditional and dual-process theories have predicted improvement in reasoning from childhood to adulthood, and improvement has been observed. However, developmental reversals--that reasoning biases emerge with development--have also been observed in a growing list of paradigms. We explain how fuzzy-trace theory predicts…

  1. Dual Sticky Hierarchical Dirichlet Process Hidden Markov Model and Its Application to Natural Language Description of Motions.

    Science.gov (United States)

    Hu, Weiming; Tian, Guodong; Kang, Yongxin; Yuan, Chunfeng; Maybank, Stephen

    2017-09-25

    In this paper, a new nonparametric Bayesian model called the dual sticky hierarchical Dirichlet process hidden Markov model (HDP-HMM) is proposed for mining activities from a collection of time series data such as trajectories. All the time series data are clustered. Each cluster of time series data, corresponding to a motion pattern, is modeled by an HMM. Our model postulates a set of HMMs that share a common set of states (topics in an analogy with topic models for document processing), but have unique transition distributions. For the application to motion trajectory modeling, topics correspond to motion activities. The learnt topics are clustered into atomic activities which are assigned predicates. We propose a Bayesian inference method to decompose a given trajectory into a sequence of atomic activities. On combining the learnt sources and sinks, semantic motion regions, and the learnt sequence of atomic activities, the action represented by the trajectory can be described in natural language in as automatic a way as possible. The effectiveness of our dual sticky HDP-HMM is validated on several trajectory datasets. The effectiveness of the natural language descriptions for motions is demonstrated on the vehicle trajectories extracted from a traffic scene.

  2. A dual-process model of diversity outcomes: The case South African police service in the Pretoria area

    Directory of Open Access Journals (Sweden)

    Leon T.B. Jackson

    2013-09-01

    Full Text Available Orientation: The study addresses the question of how employees of the South African Police Service (SAPS cope with intercultural relations in an increasingly diverse organisation. Research purpose: A dual-process model of diversity outcomes was tested in which a distinction is made between a positive (work-related stream that links positive diversity conditions through active coping to work outcomes and a relatively independent health related stream of negative antecedents, mediating passive coping skills and ill-health related outcomes. Motivation for the study: To test the viability of a dual-process model to understand diversity outcomes in the workplace. Research design, approach and methods: A convenience sample (n= 158 was recruited from members of the SAPS in Gauteng, using a cross-sectional design. Instruments used in previous acculturation research were adapted to measure contextual factors, coping and diversity outcomes. Main findings: A very good fit for the proposed hypothetical model was found. Approach coping partially mediated the relationship between positive acculturation conditions and the subjective experience of work success whereas avoidance coping fully mediated the relationship between discrimination, and ill-health symptoms are related to ill-health symptoms. Practical/managerial implications: Mainstream-facilitating conditions and discrimination influence individual coping styles, which in turn impact on ill-health and the subjective experience of work success. In addition, ill-health also impacts negatively on work-success experiences amongst the sampled SAPS members. It would thus make sense for the SAPS to sanction discrimination. Contribution/value added: A variation of the mediated dual-process model for diversity (Jackson & Van de Vijver, in press, using coping strategies as mediators was supported. The model adds new insights in diversity in organisations.

  3. Dual Dynamic Programming - DDP

    International Nuclear Information System (INIS)

    Velasquez Bermudez, Jesus M

    1998-01-01

    Objections are presented to the mathematical formulation of the denominated Dual Dynamic programming-PDD that is the theoretical base of several computational model available for the optimal formulation of interconnected hydrothermal systems

  4. Modeling the emissions of a dual fuel engine coupled with a biomass gasifier-supplementing the Wiebe function.

    Science.gov (United States)

    Vakalis, Stergios; Caligiuri, Carlo; Moustakas, Konstantinos; Malamis, Dimitris; Renzi, Massimiliano; Baratieri, Marco

    2018-03-12

    There is a growing market demand for small-scale biomass gasifiers that is driven by the economic incentives and the legislative framework. Small-scale gasifiers produce a gaseous fuel, commonly referred to as producer gas, with relatively low heating value. Thus, the most common energy conversion systems that are coupled with small-scale gasifiers are internal combustion engines. In order to increase the electrical efficiency, the operators choose dual fuel engines and mix the producer gas with diesel. The Wiebe function has been a valuable tool for assessing the efficiency of dual fuel internal combustion engines. This study introduces a thermodynamic model that works in parallel with the Wiebe function and calculates the emissions of the engines. This "vis-à-vis" approach takes into consideration the actual conditions inside the cylinders-as they are returned by the Wiebe function-and calculates the final thermodynamic equilibrium of the flue gases mixture. This approach aims to enhance the operation of the dual fuel internal combustion engines by identifying the optimal operating conditions and-at the same time-advance pollution control and minimize the environmental impact.

  5. Dual AAV therapy ameliorates exercise-induced muscle injury and functional ischemia in murine models of Duchenne muscular dystrophy.

    Science.gov (United States)

    Zhang, Yadong; Yue, Yongping; Li, Liang; Hakim, Chady H; Zhang, Keqing; Thomas, Gail D; Duan, Dongsheng

    2013-09-15

    Neuronal nitric oxide synthase (nNOS) membrane delocalization contributes to the pathogenesis of Duchenne muscular dystrophy (DMD) by promoting functional muscle ischemia and exacerbating muscle injury during exercise. We have previously shown that supra-physiological expression of nNOS-binding mini-dystrophin restores normal blood flow regulation and prevents functional ischemia in transgenic mdx mice, a DMD model. A critical next issue is whether systemic dual adeno-associated virus (AAV) gene therapy can restore nNOS-binding mini-dystrophin expression and mitigate muscle activity-related functional ischemia and injury. Here, we performed systemic gene transfer in mdx and mdx4cv mice using a pair of dual AAV vectors that expressed a 6 kb nNOS-binding mini-dystrophin gene. Vectors were packaged in tyrosine mutant AAV-9 and co-injected (5 × 10(12) viral genome particles/vector/mouse) via the tail vein to 1-month-old dystrophin-null mice. Four months later, we observed 30-50% mini-dystrophin positive myofibers in limb muscles. Treatment ameliorated histopathology, increased muscle force and protected against eccentric contraction-induced injury. Importantly, dual AAV therapy successfully prevented chronic exercise-induced muscle force drop. Doppler hemodynamic assay further showed that therapy attenuated adrenergic vasoconstriction in contracting muscle. Our results suggest that partial transduction can still ameliorate nNOS delocalization-associated functional deficiency. Further evaluation of nNOS binding mini-dystrophin dual AAV vectors is warranted in dystrophic dogs and eventually in human patients.

  6. Testing the dual-route model of perceived gaze direction: Linear combination of eye and head cues.

    Science.gov (United States)

    Otsuka, Yumiko; Mareschal, Isabelle; Clifford, Colin W G

    2016-06-01

    We have recently proposed a dual-route model of the effect of head orientation on perceived gaze direction (Otsuka, Mareschal, Calder, & Clifford, 2014; Otsuka, Mareschal, & Clifford, 2015), which computes perceived gaze direction as a linear combination of eye orientation and head orientation. By parametrically manipulating eye orientation and head orientation, we tested the adequacy of a linear model to account for the effect of horizontal head orientation on perceived direction of gaze. Here, participants adjusted an on-screen pointer toward the perceived gaze direction in two image conditions: Normal condition and Wollaston condition. Images in the Normal condition included a change in the visible part of the eye along with the change in head orientation, while images in the Wollaston condition were manipulated to have identical eye regions across head orientations. Multiple regression analysis with explanatory variables of eye orientation and head orientation revealed that linear models account for most of the variance both in the Normal condition and in the Wollaston condition. Further, we found no evidence that the model with a nonlinear term explains significantly more variance. Thus, the current study supports the dual-route model that computes the perceived gaze direction as a linear combination of eye orientation and head orientation.

  7. On the stability of the exact solutions of the dual-phase lagging model of heat conduction

    Science.gov (United States)

    Ordonez-Miranda, Jose; Alvarado-Gil, Juan Jose

    2011-12-01

    The dual-phase lagging (DPL) model has been considered as one of the most promising theoretical approaches to generalize the classical Fourier law for heat conduction involving short time and space scales. Its applicability, potential, equivalences, and possible drawbacks have been discussed in the current literature. In this study, the implications of solving the exact DPL model of heat conduction in a three-dimensional bounded domain solution are explored. Based on the principle of causality, it is shown that the temperature gradient must be always the cause and the heat flux must be the effect in the process of heat transfer under the dual-phase model. This fact establishes explicitly that the single- and DPL models with different physical origins are mathematically equivalent. In addition, taking into account the properties of the Lambert W function and by requiring that the temperature remains stable, in such a way that it does not go to infinity when the time increases, it is shown that the DPL model in its exact form cannot provide a general description of the heat conduction phenomena.

  8. Hepatitis C virus host cell interactions uncovered

    DEFF Research Database (Denmark)

    Gottwein, Judith; Bukh, Jens

    2007-01-01

      Insights into virus-host cell interactions as uncovered by Randall et al. (1) in a recent issue of PNAS further our understanding of the hepatitis C virus (HCV) life cycle, persistence, and pathogenesis and might lead to the identification of new therapeutic targets. HCV persistently infects 180...

  9. Uncovering Heart Failure in Type 2 Diabetes

    NARCIS (Netherlands)

    Boonman-de Winter, L.J.M.

    2015-01-01

    In existing disease-management-programs for type 2 diabetes there is no routine attention for uncovering latent or early stages of cardiovascular diseases, including heart failure. Between February 2009 and March 2010, 605 patients aged 60 years or over with type 2 diabetes in the south-west of the

  10. SISTEM KONTROL OTOMATIK DENGAN MODEL SINGLE-INPUT-DUAL-OUTPUT DALAM KENDALI EFISIENSI UMUR-PEMAKAIAN INSTRUMEN

    Directory of Open Access Journals (Sweden)

    S.N.M.P. Simamora

    2014-10-01

    Full Text Available Efficiency condition occurs when the value of the used outputs compared to the resource total that has been used almost close to the value 1 (absolute environment. An instrument to achieve efficiency if the power output level has decreased significantly in the life of the instrument used, if it compared to the previous condition, when the instrument is not equipped with additional systems (or proposed model improvement. Even more effective if the inputs model that are used in unison to achieve a homogeneous output. On this research has been designed and implemented the automatic control system for models of single input-dual-output, wherein the sampling instruments used are lamp and fan. Source voltage used is AC (alternate-current and tested using quantitative research methods and instrumentation (with measuring instruments are observed. The results obtained demonstrate the efficiency of the instrument experienced a significant current model of single-input-dual-output applied separately instrument trials such as lamp and fan when it compared to the condition or state before. And the result show that the design has been built, can also run well.

  11. Flexing dual-systems models: How variable cognitive control in children informs our understanding of risk-taking across development.

    Science.gov (United States)

    Li, Rosa

    2017-10-01

    Prevailing models of the development of decision-making propose that peak risk-taking occurs in adolescence due to a neural imbalance between two processes: gradual, linearly developing cognitive control and rapid, non-linearly developing reward-processing. Though many studies have found neural evidence supporting this dual-systems imbalance model, its behavioral predictions have been surprisingly difficult to document. Most laboratory studies have not found adolescents to exhibit greater risk-taking than children, and public health data show everyday risk-taking to peak in late adolescence/early adulthood. Moreover, when adolescents are provided detailed information about decision options and consequences, they evince similar behavior to adults. Such findings point to a critical feature of the development of decision-making that is missed by imbalance models. Specifically, the engagement of cognitive control is context dependent, such that cognitive control and therefore advantageous decision-making increases when available information is high and decreases when available information is low. Furthermore, the context dependence of cognitive control varies across development, such that increased information availability benefits children more than adolescents, who benefit more than adults. This review advances a flexible dual-systems model that is only imbalanced under certain conditions; explains disparities between neural, behavioral, and public health findings; and provides testable hypotheses for future research. Copyright © 2017 The Author. Published by Elsevier Ltd.. All rights reserved.

  12. A Warm-Started Homogeneous and Self-Dual Interior-Point Method for Linear Economic Model Predictive Control

    DEFF Research Database (Denmark)

    Sokoler, Leo Emil; Skajaa, Anders; Frison, Gianluca

    2013-01-01

    algorithm in MATLAB and its performance is analyzed based on a smart grid power management case study. Closed loop simulations show that 1) our algorithm is significantly faster than state-of-the-art IPMs based on sparse linear algebra routines, and 2) warm-starting reduces the number of iterations......In this paper, we present a warm-started homogenous and self-dual interior-point method (IPM) for the linear programs arising in economic model predictive control (MPC) of linear systems. To exploit the structure in the optimization problems, our algorithm utilizes a Riccati iteration procedure...

  13. Strangeness production in hadron-hadron, hadron-nucleus, and nucleus-nucleus collisions in the dual parton model

    International Nuclear Information System (INIS)

    Moehring, H.; Ranft, J.; Capella, A.; Tran Thanh Van, J.

    1993-01-01

    Λ, bar Λ, and K S 0 production is studied in a Monte Carlo dual parton model for hadron-hadron, hadron-nucleus, and nucleus-nucleus collisions with an SU(3) symmetric sea for chain formation (chain ends) but strangeness suppression in the chain fragmentation process. Additionally, (qq)-(bar q bar q) production from the sea was introduced into the chain formation process with the same probability as for the q→qq branching within the chain decay process. With these assumptions, multiplicity ratios and Feynman-x distributions for strange particles in h-h and multiplicity ratios in heavy ion collisions are reasonably well reproduced

  14. Modeling and control of a novel dual-stator brushless doubly-fed wind power generation system

    DEFF Research Database (Denmark)

    Cheng, Ming; Wei, Xinchi; Han, Peng

    2014-01-01

    A novel dual-stator brushless doubly-fed induction generator-based wind power generation system (DSBDFIG-WPGS), with the merits of reduced converter scale, compact structure and high reliability, is proposed in this paper. System topology, operational principle and power flow of the DSBDFIG......-WPGS are analyzed. Based on the modelling of the system, a vector control scheme is proposed to realize decoupled control of the reactive power and the speed. Furthermore, a speed based maximum power point tracking method is adopted in the system. The simulation results demonstrate stable operation of the DSBDFIG...

  15. Modeling of Single Event Transients With Dual Double-Exponential Current Sources: Implications for Logic Cell Characterization

    Science.gov (United States)

    Black, Dolores A.; Robinson, William H.; Wilcox, Ian Z.; Limbrick, Daniel B.; Black, Jeffrey D.

    2015-08-01

    Single event effects (SEE) are a reliability concern for modern microelectronics. Bit corruptions can be caused by single event upsets (SEUs) in the storage cells or by sampling single event transients (SETs) from a logic path. An accurate prediction of soft error susceptibility from SETs requires good models to convert collected charge into compact descriptions of the current injection process. This paper describes a simple, yet effective, method to model the current waveform resulting from a charge collection event for SET circuit simulations. The model uses two double-exponential current sources in parallel, and the results illustrate why a conventional model based on one double-exponential source can be incomplete. A small set of logic cells with varying input conditions, drive strength, and output loading are simulated to extract the parameters for the dual double-exponential current sources. The parameters are based upon both the node capacitance and the restoring current (i.e., drive strength) of the logic cell.

  16. Design, modeling and performance analysis of dual channel semitransparent photovoltaic thermal hybrid module in the cold environment

    International Nuclear Information System (INIS)

    Singh, Sonveer; Agrawal, Sanjay; Avasthi, D.V.

    2016-01-01

    Highlights: • Thermal modeling of novel dual channel semitransparent PVT hybrid module. • Exergy and carbon credit analysis has been performed. • Annual performance has been evaluated for Srinagar (India). • There are improvements in results for case-I as compared to case-II. - Abstract: In this work, thermal modeling and performance analysis of the dual channel semitransparent photovoltaic thermal (DCSPVT) module has been carried out. For extracting heat associated with the lower and upper surface of the solar cell, two channels have been proposed; (i) one is above the solar cell called upper channel and (ii) second is below the solar cell called lower channel. Firstly, thermal modeling of DCSPVT module has been developed. After that, performance analysis of the above system has been carried out for Srinagar, Indian climatic condition. Performance in terms of electrical gain (EG), thermal gain (TG), overall exergy gain (OEG), overall thermal gain (OTG), electrical efficiency (EE) and overall exergy efficiency (OEE) of the DCSPVT module (case-I) have been compared with single channel semitransparent photovoltaic thermal (SCSPVT) hybrid module (case-II). The average improvement in EG, TG, OEG, OTG of the case-I have been observed by 71.51%, 34.57%, 5.78% and 35.41% respectively as compared to case-II.

  17. Caregiver social support quality when interacting with cancer survivors: advancing the dual-process model of supportive communication.

    Science.gov (United States)

    Harvey-Knowles, Jacquelyn; Faw, Meara H

    2018-04-01

    Cancer caregivers often experience significant challenges in their motivation and ability to comfort cancer survivors, particularly in a spousal or romantic context. Spousal cancer caregivers have been known to report even greater levels of burden and distress than cancer sufferers, yet still take on the role of acting as an informal caregiver so they can attend to their partner's needs. The current study tested whether a theoretical model of supportive outcomes-the dual-process model of supportive communication-explained variations in cancer caregivers' motivation and ability to create high-quality support messages. The study also tested whether participant engagement with reflective journaling on supportive acts was associated with increased motivation or ability to generate high-quality support messages. Based upon the dual-process model, we posited that, following supportive journaling tasks, caregivers of spouses currently managing a cancer experience would report greater motivation but also greater difficulty in generating high-quality support messages, while individuals caring for a patient in remission would report lower motivation but greater ability to create high-quality support messages. Findings provided support for these assertions and suggested that reflective journaling tasks might be a useful tool for improving remission caregivers' ability to provide high-quality social support to survivors. Corresponding theoretical and applied implications are discussed.

  18. Uncovering the FUTREX-6100XL prediction equation for the percentage body fat.

    Science.gov (United States)

    Fthenakis, Zacharias G; Balaska, Dimitra; Zafiropulos, Vassilis

    2012-10-01

    Based on the near infra-red (NIR) interactance method, the FUTREX company has developed a series of instruments, for the estimation of the body fat percentage (%BF). %BF is estimated through prediction equations incorporated in the instruments, which for the newest models (FUTREX-6100XL and FUTREX-6100A/ZL) are proprietary and they are not published anywhere. This missing knowledge may lead to several misunderstandings and confusion and degrades those instruments to 'black boxes'. The present work uncovers and presents the prediction equation of FUTREX-6100/XL and discusses the contribution of each term of that equation to the %BF. Furthermore, this study presents the method used, which can be used to uncover equations incorporated in other instruments. This method is based on the idea of firstly uncovering the dependence of the equation on each parameter separately and then combining those dependencies to uncover the unknown equation.

  19. Complexity Uncertainty Analysis of Dynamic in a Dual-Channel Energy Supply Chain Model with Heterogeneous Retailers

    Directory of Open Access Journals (Sweden)

    Ting Li

    2015-01-01

    Full Text Available This paper analyses the dynamics of dual-channel energy supply chain model with heterogeneous retailers (as regards the type of expectations’ formation. On the basis of analyzing the stabilities of four fixed points in the three-dimensional dynamic system, local stable regions of Nash equilibrium are obtained. Effects of S on the stable regions and profit are studied. Simulation results show that the adjustment of price speed has an obvious impact on the complexity of competition. The performances of the model in different period are measured by using the index of average profit. The results show that unstable behavior in economic system is often an unfavorable outcome. So this paper discusses the application of parameters control method when the model is in chaos and then allows the oligarchs to eliminate the negative effects.

  20. Vector and tensor meson production in quasi-two-body final states using the dual fermion model

    International Nuclear Information System (INIS)

    Becker, L.; Matthaeus, E.; Weigt, G.

    1976-01-01

    Phenomenological dual fermion amplitudes are obtained by using Neveu-Schwarz-Ramond model as a guide to incorporate half-integer spin. The model relates the production mechanism of different resonances lying on the same degenerate Regge trajectory, thus allowing a simultaneous description of vector and tensor meson production. A characteristic feature of the amplitudes is their non-evasive coupling structure. Predictions of the model for rho 0 -f-g 0 , ω-A 2 - and anti K*(890)-anti K*(1420) production in quasi-two-body reactions are compared with experimental data. The differential cross sections for natural and unnatural spin-parity t-channel exchanges as well as their contributions to different helicities of the produced resonances are given. In particular, new properties arise from the non-evasive pion exchange. Reasonable agreement with the data is found. (Auth.)

  1. Vector and tensor meson production in quasi-two-body final states using the dual fermion model

    International Nuclear Information System (INIS)

    Becker, L.; Matthaeus, E.; Weigt, G.

    1975-01-01

    Phenomenological dual fermion amplitudes are obtained by using the Neveu-Schwarz-Ramond model as a guide to incorporate half-integer spin. The model relates the production mechanism of different resonances lying on the same degenerated Regge trajectory, thus allowing a simultaneous description of vector and tensor meson production. A characteristic feature of the amplitudes is their non-evasive coupling structure. Predictions of the model for rho 0 - f - g 0 , ω - A 2 - and anti K-890 and anti K-1420 resonances production in quasi-two-body reactions are compared with experimental data. The differential cross sections for natural and unnatural spin-parity t-channel exchanges as well as their contributions to different helicities of the produced resonances are given. In particular, new properties arise from the non-evasive pion exchange. Reasonable agreement with the data is found. (author)

  2. Dual mTORC1/mTORC2 blocker as a possible therapy for tauopathy in cellular model.

    Science.gov (United States)

    Salama, Mohamed; Elhussiny, Mahmoud; Magdy, Alshimaa; Omran, Ahmed G; Alsayed, Aziza; Ashry, Ramy; Mohamed, Wael

    2017-10-27

    Tauopathy comprises a group of disorders caused by abnormal aggregates of tau protein. In these disorders phosphorylated tau protein tends to accumulate inside neuronal cells (soma) instead of the normal axonal distribution of tau. A suggested therapeutic strategy for tauopathy is to induce autophagy to increase the ability to get rid of the unwanted tau aggregates. One of the key controllers of autophagy is mTOR. Blocking mTOR leads to stimulation of autophagy. Recently, unravelling molecular structure of mTOR showed that it is formed of two subunits: mTORC1/C2. So, blocking both subunits of mTOR seems more attractive as it will explore all abilities of mTOR molecule. In the present study, we report using pp242 which is a dual mTORC1/C2 blocker in cellular model of tauopathy using LUHMES cell line. Adding fenazaquin to LUHMES cells induced tauopathy in the form of increased phospho tau aggregates. Moreover, fenazaquin treated cells showed the characteristic somatic redistribution of tau. PP242 use in the present tauopathy model reversed the pathology significantly without observable cellular toxicity for the used dosage of 1000 nM. The present study suggests the possible use of pp242 as a dual mTOR blocker to treat tauopathy.

  3. A Hybrid Dual-Source Model of Estimating Evapotranspiration over Different Ecosystems and Implications for Satellite-Based Approaches

    Directory of Open Access Journals (Sweden)

    Hanyu Lu

    2014-09-01

    Full Text Available Accurate estimation of evapotranspiration (ET and its components is critical to developing a better understanding of climate, hydrology, and vegetation coverage conditions for areas of interest. A hybrid dual-source (H-D model incorporating the strengths of the two-layer and two-patch schemes was proposed to estimate actual ET processes by considering varying vegetation coverage patterns and soil moisture conditions. The proposed model was tested in four different ecosystems, including deciduous broadleaf forest, woody savannas, grassland, and cropland. Performance of the H-D model was compared with that of the Penman-Monteith (P-M model, the Shuttleworth-Wallace (S-W model, as well as the Two-Patch (T-P model, with ET and/or its components (i.e., transpiration and evaporation being evaluated against eddy covariance measurements. Overall, ET estimates from the developed H-D model agreed reasonably well with the ground-based measurements at all sites, with mean absolute errors ranging from 16.3 W/m2 to 38.6 W/m2, indicating good performance of the H-D model in all ecosystems being tested. In addition, the H-D model provides a more reasonable partitioning of evaporation and transpiration than other models in the ecosystems tested.

  4. Multiscale Modeling using Molecular Dynamics and Dual Domain Material Point Method

    Energy Technology Data Exchange (ETDEWEB)

    Dhakal, Tilak Raj [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division. Fluid Dynamics and Solid Mechanics Group, T-3; Rice Univ., Houston, TX (United States)

    2016-07-07

    For problems involving large material deformation rate, the material deformation time scale can be shorter than the material takes to reach a thermodynamical equilibrium. For such problems, it is difficult to obtain a constitutive relation. History dependency become important because of thermodynamic non-equilibrium. Our goal is to build a multi-scale numerical method which can bypass the need for a constitutive relation. In conclusion, multi-scale simulation method is developed based on the dual domain material point (DDMP). Molecular dynamics (MD) simulation is performed to calculate stress. Since the communication among material points is not necessary, the computation can be done embarrassingly parallel in CPU-GPU platform.

  5. Final Technical Report - Integrated Hydrogeophysical and Hydrogeologic Driven Parameter Upscaling for Dual-Domain Transport Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Shafer, John M

    2012-11-05

    The three major components of this research were: 1. Application of minimally invasive, cost effective hydrogeophysical techniques (surface and borehole), to generate fine scale (~1m or less) 3D estimates of subsurface heterogeneity. Heterogeneity is defined as spatial variability in hydraulic conductivity and/or hydrolithologic zones. 2. Integration of the fine scale characterization of hydrogeologic parameters with the hydrogeologic facies to upscale the finer scale assessment of heterogeneity to field scale. 3. Determination of the relationship between dual-domain parameters and practical characterization data.

  6. Uncovering student ideas in physical science

    CERN Document Server

    Keeley, Page

    2014-01-01

    If you and your students can't get enough of a good thing, Volume 2 of Uncovering Student Ideas in Physical Science is just what you need. The book offers 39 new formative assessment probes, this time with a focus on electric charge, electric current, and magnets and electromagnetism. It can help you do everything from demystify electromagnetic fields to explain the real reason balloons stick to the wall after you rub them on your hair.

  7. Tree-level equivalence between a Lorentz-violating extension of QED and its dual model in electron-electron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Toniolo, Giuliano R.; Fargnoli, H.G.; Brito, L.C.T. [Universidade Federal de Lavras, Departamento de Fisica, Caixa Postal 3037, Lavras, Minas Gerais (Brazil); Scarpelli, A.P.B. [Setor Tecnico-Cientifico, Departamento de Policia Federal, Sao Paulo (Brazil)

    2017-02-15

    S-matrix amplitudes for the electron-electron scattering are calculated in order to verify the physical equivalence between two Lorentz-breaking dual models. We begin with an extended Quantum Electrodynamics which incorporates CPT-even Lorentz-violating kinetic and mass terms. Then, in a process of gauge embedding, its gauge-invariant dual model is obtained. The physical equivalence of the two models is established at tree level in the electron-electron scattering and the unpolarized cross section is calculated up to second order in the Lorentz-violating parameter. (orig.)

  8. Familial Brugada syndrome uncovered by hyperkalaemic diabetic ketoacidosis

    NARCIS (Netherlands)

    Postema, Pieter G.; Vlaar, Alexander P. J.; DeVries, J. Hans; Tan, Hanno L.

    2011-01-01

    We describe a case of diabetic ketoacidosis with concomitant hyperkalaemia that uncovered a typical Brugada syndrome electrocardiogram (ECG). Further provocation testing in the patient and his son confirmed familial Brugada syndrome. Diabetic ketoacidosis with hyperkalaemia may uncover an

  9. A Priori Analysis of a Compressible Flamelet Model using RANS Data for a Dual-Mode Scramjet Combustor

    Science.gov (United States)

    Quinlan, Jesse R.; Drozda, Tomasz G.; McDaniel, James C.; Lacaze, Guilhem; Oefelein, Joseph

    2015-01-01

    In an effort to make large eddy simulation of hydrocarbon-fueled scramjet combustors more computationally accessible using realistic chemical reaction mechanisms, a compressible flamelet/progress variable (FPV) model was proposed that extends current FPV model formulations to high-speed, compressible flows. Development of this model relied on observations garnered from an a priori analysis of the Reynolds-Averaged Navier-Stokes (RANS) data obtained for the Hypersonic International Flight Research and Experimentation (HI-FiRE) dual-mode scramjet combustor. The RANS data were obtained using a reduced chemical mechanism for the combustion of a JP-7 surrogate and were validated using avail- able experimental data. These RANS data were then post-processed to obtain, in an a priori fashion, the scalar fields corresponding to an FPV-based modeling approach. In the current work, in addition to the proposed compressible flamelet model, a standard incompressible FPV model was also considered. Several candidate progress variables were investigated for their ability to recover static temperature and major and minor product species. The effects of pressure and temperature on the tabulated progress variable source term were characterized, and model coupling terms embedded in the Reynolds- averaged Navier-Stokes equations were studied. Finally, results for the novel compressible flamelet/progress variable model were presented to demonstrate the improvement attained by modeling the effects of pressure and flamelet boundary conditions on the combustion.

  10. Dual Criteria Decisions

    DEFF Research Database (Denmark)

    Andersen, Steffen; Harrison, Glenn W.; Lau, Morten Igel

    2014-01-01

    The most popular models of decision making use a single criterion to evaluate projects or lotteries. However, decision makers may actually consider multiple criteria when evaluating projects. We consider a dual criteria model from psychology. This model integrates the familiar tradeoffs between...

  11. Self-Enhancement on a Self-Categorization Leash: Evidence for a Dual-Process Model of First-and Third-Person Perceptions

    Science.gov (United States)

    Zhang, Jinguang

    2010-01-01

    Research suggests that first- and third-person perceptions are driven by the motive to self-enhance and cognitive processes involving the perception of social norms. This article proposes and tests a dual-process model that predicts an interaction between cognition and motivation. Consistent with the model, Experiment 1 (N = 112) showed that…

  12. Rapidity spectra in proton-proton and proton-antiproton scattering up to 540 GeV in a dual parton model

    International Nuclear Information System (INIS)

    Aurenche, P.; Bopp, F.W.

    1982-01-01

    Some recent data at the ISR and SPS colliders are discussed in terms of a multi-Pomeron exchange model formulated in the dual parton framework. Charged particle rapidity distributions, energy dependence of the central plateau, ratio of particle densities in proton-proton and antiproton-proton scattering and non diffractive multiplicities are successfully accounted for in the model

  13. Estimation and upscaling of dual-permeability model parameters for the transport of E.coli D21g in soils with preferential flow

    Science.gov (United States)

    Dual-permeability models are increasingly used to quantify the transport of solutes and microorganisms in soils with preferential flow. An ability to accurately determine the model parameters and their variation with preferential pathway characteristics is crucial for predicting the transport of mi...

  14. Dual Transformer Model based on Standard Circuit Elements for the Study of Low- and Mid-frequency Transients

    Science.gov (United States)

    Jazebi, Saeed

    This thesis is a step forward toward achieving the final objective of creating a fully dual model for transformers including eddy currents and nonlinearities of the iron core using the fundamental electrical components already available in the EMTP-type programs. The model is effective for the study of the performance of transformers during power system transients. This is very important for transformer designers, because the insulation of transformers is determined with the overvoltages caused by lightning or switching operations. There are also internally induced transients that occur when a switch is actuated. For example switching actions for reconfiguration of distribution systems that offers economic advantages, or protective actions to clear faults and large short-circuit currents. Many of the smart grid concepts currently under development by many utilities rely heavily on switching to optimize resources that produce transients in the system. On the other hand, inrush currents produce mechanical forces which deform transformer windings and cause malfunction of the differential protection. Also, transformer performance under ferroresonance and geomagnetic induced currents are necessary to study. In this thesis, a physically consistent dual model applicable to single-phase two-winding transformers is proposed. First, the topology of a dual electrical equivalent circuit is obtained from the direct application of the principle of duality. Then, the model parameters are computed considering the variations of the transformer electromagnetic behavior under various operating conditions. Current modeling techniques use different topological models to represent diverse transient situations. The reversible model proposed in this thesis unifies the terminal and topological equivalent circuits. The model remains invariable for all low-frequency transients including deep saturation conditions driven from any of the two windings. The very high saturation region of the

  15. Big-five personality, social worldviews, and ideological attitudes: further tests of a dual process cognitive-motivational model.

    Science.gov (United States)

    Sibley, Chris G; Duckitt, John

    2009-10-01

    In this study, we extended the Dual Process Model of Ideology and Prejudice by incorporating the Five-Factor Model of Personality (N = 924). Disagreeable people tended to view the social world as competitive, which in turn predicted heightened motivations for group-based dominance and superiority (Social Dominance Orientation or SDO), whereas people low in Openness to Experience and high in Conscientiousness directly expressed heightened security-cohesion motivations (Right-Wing Authoritarianism or RWA). Other personality dimensions were weakly associated with RWA, and these effects were mediated by dangerous worldview. Multiple distinct aspects of personality predict SDO and RWA both directly and indirectly through worldviews, but we found little evidence for the possibility that personality alters the extent to which worldviews (once formed) predict SDO and RWA.

  16. An off-line dual maximum resource bin packing model for solving the maintenance problem in the aviation industry

    Directory of Open Access Journals (Sweden)

    George Cristian Gruia

    2013-05-01

    Full Text Available In the aviation industry, propeller motor engines have a lifecycle of several thousand hours of flight and the maintenance is an important part of their lifecycle. The present article considers a multi-resource, priority-based case scheduling problem, which is applied in a Romanian manufacturing company, that repairs and maintains helicopter and airplane engines at a certain quality level imposed by the aviation standards. Given a reduced budget constraint, the management’s goal is to maximize the utilization of their resources (financial, material, space, workers, by maintaining a prior known priority rule. An Off-Line Dual Maximum Resource Bin Packing model, based on a Mixed Integer Programming model is thus presented. The obtained results show an increase with approx. 25% of the Just in Time shipping of the engines to the customers and approx. 12,5% increase in the utilization of the working area.

  17. A Bayesian supervised dual-dimensionality reduction model for simultaneous decoding of LFP and spike train signals.

    Science.gov (United States)

    Holbrook, Andrew; Vandenberg-Rodes, Alexander; Fortin, Norbert; Shahbaba, Babak

    2017-01-01

    Neuroscientists are increasingly collecting multimodal data during experiments and observational studies. Different data modalities-such as EEG, fMRI, LFP, and spike trains-offer different views of the complex systems contributing to neural phenomena. Here, we focus on joint modeling of LFP and spike train data, and present a novel Bayesian method for neural decoding to infer behavioral and experimental conditions. This model performs supervised dual-dimensionality reduction: it learns low-dimensional representations of two different sources of information that not only explain variation in the input data itself, but also predict extra-neuronal outcomes. Despite being one probabilistic unit, the model consists of multiple modules: exponential PCA and wavelet PCA are used for dimensionality reduction in the spike train and LFP modules, respectively; these modules simultaneously interface with a Bayesian binary regression module. We demonstrate how this model may be used for prediction, parametric inference, and identification of influential predictors. In prediction, the hierarchical model outperforms other models trained on LFP alone, spike train alone, and combined LFP and spike train data. We compare two methods for modeling the loading matrix and find them to perform similarly. Finally, model parameters and their posterior distributions yield scientific insights.

  18. Fabrication of BCP/Silica Scaffolds with Dual-Pore by Combining Fused Deposition Modeling and the Particle Leaching Method

    Energy Technology Data Exchange (ETDEWEB)

    Sa, Min-Woo; Kim, Jong Young [Andong National Univ., Andong (Korea, Republic of)

    2016-10-15

    In recent years, traditional scaffold fabrication techniques such as gas foaming, salt leaching, sponge replica, and freeze casting in tissue engineering have significantly limited sufficient mechanical property and cell interaction effect due to only random pores. Fused deposition modeling is the most apposite technology for fabricating the 3D scaffolds using the polymeric materials in tissue engineering application. In this study, 3D slurry mould was fabricated with a blended biphasic calcium phosphate (BCP)/Silica/Alginic acid sodium salt slurry in PCL mould and heated for two hours at 100 .deg. C to harden the blended slurry. 3D dual-pore BCP/Silica scaffold, composed of macro pores interconnected with micro pores, was successfully fabricated by sintering at furnace of 1100 .deg. C. Surface morphology and 3D shape of dual-pore BCP/Silica scaffold from scanning electron microscopy were observed. Also, the mechanical properties of 3D BCP/Silica scaffold, according to blending ratio of alginic acid sodium salt, were evaluated through compression test.

  19. Bilingual teaching for multilingual students? Innovative dual-medium models in Slovene-German schools in Austria

    Science.gov (United States)

    Purkarthofer, Judith; Mossakowski, Jan

    2011-12-01

    Traditional bilingual education programmes in regional linguistic minority contexts face major challenges within the recent paradigm of linguistic diversity against a background of increasing migration, mobility and trans-locality. Based on three case studies, the authors of this paper focus on how particular dual-medium models are applied in Slovene-German schools in Carinthia, Austria. They examine not only how these schools provide for a balanced bilingual teaching and learning environment, but also how they deal with their students' multilingual realities and support their identification with bi- and multilingualism. The authors regard schools as institutional sites where linguistic dispositions are subject to discursive power relations and where language policies and educational goals are negotiated by teachers, parents and students alike. Drawing on speaker-centred and ethnographic approaches in sociolinguistic research, the authors seek to document experiences of all actors involved as well as spatial and discursive practices. Through this the authors show how these dual-medium schools achieve particular profiles in multilingual education which are potentially regarded as innovative examples of best-practice and as being of interest for students and families with heterogeneous linguistic backgrounds.

  20. Multiple-Echo Suppression Modeling and Experimental Verification for Acoustic Transmission along Periodic Drillstring Using Dual Receivers

    Directory of Open Access Journals (Sweden)

    Li Cheng

    2014-01-01

    Full Text Available In the oil industry, the accompanied reverberation is a major constraint in the transmission rate and distance because the drillstring is a heterogeneous assembly. Based on the transient impulse responses in uplink and downlink channels, an improved simplified echo suppression model with two acoustic receivers is presented in consideration of position optimization of single acoustic receiver. Then the acoustic receiving characteristics of transmitted signals in a length-limited periodic drillstring channel are obtained in single- and dual-receiver modes. An additive downward white Gaussian noise is also introduced in the channel. Moreover, an experimental rig is established by using a rotatable electromagnetic vibration exciter and two piezoelectric accelerometers, which are spaced one-quarter wavelength apart along a 6.3-meter simulated periodic drillstring. The ASK-, FSK-, and PSK-modulated square-wave pulse sequences at a transmission rate of 200 bit/s are applied to the simulated drillstring at a rotation speed of 0, 80, and 140 r/min, respectively. The experimental results show that the dual-receiver mode can exhibit a significantly improved average error bit ratio, which is approximately 2.5 to 3 times lower than that of the single-receiver mode, especially under the conditions of higher rotation speeds.

  1. Accurate Energy Consumption Modeling of IEEE 802.15.4e TSCH Using Dual-Band OpenMote Hardware

    Directory of Open Access Journals (Sweden)

    Glenn Daneels

    2018-02-01

    Full Text Available The Time-Slotted Channel Hopping (TSCH mode of the IEEE 802.15.4e amendment aims to improve reliability and energy efficiency in industrial and other challenging Internet-of-Things (IoT environments. This paper presents an accurate and up-to-date energy consumption model for devices using this IEEE 802.15.4e TSCH mode. The model identifies all network-related CPU and radio state changes, thus providing a precise representation of the device behavior and an accurate prediction of its energy consumption. Moreover, energy measurements were performed with a dual-band OpenMote device, running the OpenWSN firmware. This allows the model to be used for devices using 2.4 GHz, as well as 868 MHz. Using these measurements, several network simulations were conducted to observe the TSCH energy consumption effects in end-to-end communication for both frequency bands. Experimental verification of the model shows that it accurately models the consumption for all possible packet sizes and that the calculated consumption on average differs less than 3% from the measured consumption. This deviation includes measurement inaccuracies and the variations of the guard time. As such, the proposed model is very suitable for accurate energy consumption modeling of TSCH networks.

  2. Accurate Energy Consumption Modeling of IEEE 802.15.4e TSCH Using Dual-BandOpenMote Hardware.

    Science.gov (United States)

    Daneels, Glenn; Municio, Esteban; Van de Velde, Bruno; Ergeerts, Glenn; Weyn, Maarten; Latré, Steven; Famaey, Jeroen

    2018-02-02

    The Time-Slotted Channel Hopping (TSCH) mode of the IEEE 802.15.4e amendment aims to improve reliability and energy efficiency in industrial and other challenging Internet-of-Things (IoT) environments. This paper presents an accurate and up-to-date energy consumption model for devices using this IEEE 802.15.4e TSCH mode. The model identifies all network-related CPU and radio state changes, thus providing a precise representation of the device behavior and an accurate prediction of its energy consumption. Moreover, energy measurements were performed with a dual-band OpenMote device, running the OpenWSN firmware. This allows the model to be used for devices using 2.4 GHz, as well as 868 MHz. Using these measurements, several network simulations were conducted to observe the TSCH energy consumption effects in end-to-end communication for both frequency bands. Experimental verification of the model shows that it accurately models the consumption for all possible packet sizes and that the calculated consumption on average differs less than 3% from the measured consumption. This deviation includes measurement inaccuracies and the variations of the guard time. As such, the proposed model is very suitable for accurate energy consumption modeling of TSCH networks.

  3. A Roll Controlling Approach for a Simple Dual-Actuated Flapping Aerial Vehicle Model

    Directory of Open Access Journals (Sweden)

    Labib Omar El-Farouk E.

    2016-01-01

    Full Text Available Aerial vehicles have been investigated recently in different contexts, due to their high potential of utilization in multiple application areas. Different mechanisms can be used for aerial vehicles actuation, such as the rotating multi-blade systems (Multi-Copters and more recently flapping wings. Flapping wing robots have attracted much attention from researchers in recent years. In this study, a simple dual-actuated flapping mechanism is proposed for actuating a flapping wing robot. The mechanism is designed, simulated and validated in both simulation and experiments. A roll controlling approach is proposed to control the roll angle of the robot via controlling the speeds of both motors actuating each of the wings. The results achieved are validated experimentally, and are promising opening the door for further investigation using our proposed system

  4. Dual-phase steel sheets under cyclic tension-compression to large strains: Experiments and crystal plasticity modeling

    Science.gov (United States)

    Zecevic, Milovan; Korkolis, Yannis P.; Kuwabara, Toshihiko; Knezevic, Marko

    2016-11-01

    In this work, we develop a physically-based crystal plasticity model for the prediction of cyclic tension-compression deformation of multi-phase materials, specifically dual-phase (DP) steels. The model is elasto-plastic in nature and integrates a hardening law based on statistically stored dislocation density, localized hardening due to geometrically necessary dislocations (GNDs), slip-system-level kinematic backstresses, and annihilation of dislocations. The model further features a two level homogenization scheme where the first level is the overall response of a two-phase polycrystalline aggregate and the second level is the homogenized response of the martensite polycrystalline regions. The model is applied to simulate a cyclic tension-compression-tension deformation behavior of DP590 steel sheets. From experiments, we observe that the material exhibits a typical decreasing hardening rate during forward loading, followed by a linear and then a non-linear unloading upon the load reversal, the Bauschinger effect, and changes in hardening rate during strain reversals. To predict these effects, we identify the model parameters using a portion of the measured data and validate and verify them using the remaining data. The developed model is capable of predicting all the particular features of the cyclic deformation of DP590 steel, with great accuracy. From the predictions, we infer and discuss the effects of GNDs, the backstresses, dislocation annihilation, and the two-level homogenization scheme on capturing the cyclic deformation behavior of the material.

  5. Temporal dynamics of interference in Simon and Eriksen tasks considered within the context of a dual-process model.

    Science.gov (United States)

    Mansfield, Karen L; van der Molen, Maurits W; Falkenstein, Michael; van Boxtel, Geert J M

    2013-08-01

    Behavioral and brain potential measures were employed to compare interference in Eriksen and Simon tasks. Assuming a dual-process model of interference elicited in speeded response tasks, we hypothesized that only lateralized stimuli in the Simon task induce fast S-R priming via direct unconditional processes, while Eriksen interference effects are induced later via indirect conditional processes. Delays to responses for incongruent trials were indeed larger in the Eriksen than in the Simon task. Only lateralized stimuli in the Simon task elicited early S-R priming, maximal at parietal areas. Incongruent flankers in the Eriksen task elicited interference later, visible as a lateralized N2. Eriksen interference also elicited an additional component (N350), which accounted for the larger behavioral interference effects in the Eriksen task. The findings suggest that interference and its resolution involve different processes for Simon and Eriksen tasks. Copyright © 2013 Elsevier Inc. All rights reserved.

  6. Soft tissue freezing process. Identification of the dual-phase lag model parameters using the evolutionary algorithm

    Science.gov (United States)

    Mochnacki, Bohdan; Majchrzak, Ewa; Paruch, Marek

    2018-01-01

    In the paper the soft tissue freezing process is considered. The tissue sub-domain is subjected to the action of cylindrical cryoprobe. Thermal processes proceeding in the domain considered are described using the dual-phase lag equation (DPLE) supplemented by the appropriate boundary and initial conditions. DPLE results from the generalization of the Fourier law in which two lag times are introduced (relaxation and thermalization times). The aim of research is the identification of these parameters on the basis of measured cooling curves at the set of points selected from the tissue domain. To solve the problem the evolutionary algorithms are used. The paper contains the mathematical model of the tissue freezing process, the very short information concerning the numerical solution of the basic problem, the description of the inverse problem solution and the results of computations.

  7. The Nature of Hyperactivity in Children and Adolescents With Hydrocephalus: A Test of the Dual Pathway Model

    Science.gov (United States)

    Stevenson, Jim; Cate, Ineke Pit-ten

    2004-01-01

    To determine the strength and nature of the association between hydrocephalus and hyperactivity and to test the dual pathway model (DPM) of AD/HD, we compared a group of 51 children and adolescents with hydrocephalus with 57 normally developing controls from the general population on a battery of neuropsychological assessments. The mean hyperactivity scores were significantly greater in the group with hydrocephalus (effect size =0.94). This association was not just part of a general elevated rate of behavior problems and was not affected by sex or age. Variation in the clinical features of hydrocephalus was not related to the severity of hyperactivity. Path analysis was used to examine the relation between IQ, delay aversion, and executive function. In accordance with the DPM, the effect of hydrocephalus on hyperactivity was completely mediated via delay aversion and executive functions. PMID:15303302

  8. Anti-HIV-1 activity of flavonoid myricetin on HIV-1 infection in a dual-chamber in vitro model.

    Directory of Open Access Journals (Sweden)

    Silvana Pasetto

    Full Text Available HIV infection by sexual transmission remains an enormous global health concern. More than 1 million new infections among women occur annually. Microbicides represent a promising prevention strategy that women can easily control. Among emerging therapies, natural small molecules such as flavonoids are an important source of new active substances. In this study we report the in vitro cytotoxicity and anti-HIV-1 and microbicide activity of the following flavonoids: Myricetin, Quercetin and Pinocembrin. Cytotoxicity tests were conducted on TZM-bl, HeLa, PBMC, and H9 cell cultures using 0.01-100 µM concentrations. Myricetin presented the lowest toxic effect, with Quercetin and Pinocembrin relatively more toxic. The anti-HIV-1 activity was tested with TZM-bl cell plus HIV-1 BaL (R5 tropic, H9 and PBMC cells plus HIV-1 MN (X4 tropic, and the dual tropic (X4R5 HIV-1 89.6. All flavonoids showed anti-HIV activity, although Myricetin was more effective than Quercetin or Pinocembrin. In TZM-bl cells, Myricetin inhibited ≥90% of HIV-1 BaL infection. The results were confirmed by quantification of HIV-1 p24 antigen in supernatant from H9 and PBMC cells following flavonoid treatment. In H9 and PBMC cells infected by HIV-1 MN and HIV-1 89.6, Myricetin showed more than 80% anti-HIV activity. Quercetin and Pinocembrin presented modest anti-HIV activity in all experiments. Myricetin activity was tested against HIV-RT and inhibited the enzyme by 49%. Microbicide activities were evaluated using a dual-chamber female genital tract model. In the in vitro microbicide activity model, Myricetin showed promising results against different strains of HIV-1 while also showing insignificant cytotoxic effects. Further studies of Myricetin should be performed to identify its molecular targets in order to provide a solid biological foundation for translational research.

  9. Physiological Synchronization in a Vigilance Dual Task.

    Science.gov (United States)

    Guastello, Stephen J

    2016-01-01

    The synchronization of autonomic arousal levels and other physio-logical responses between people is a potentially important component of work team performance, client-therapist relationships, and other types of human interaction. This study addressed several problems: What statistical models are viable for identifying synchronization for loosely coupled human systems? How is the level of synchronization related to psychosocial variables such as empathy, subjective ratings of workload, and actual performance? Participants were 70 undergraduates who worked in pairs on a vigilance dual task in which they watched a virtual reality security camera, rang a bell when they saw the target intruder, and completed a jig-saw puzzle. Event rates either increased or decreased during the 90 min work period. The average R2 values for each person were .66, .66, .62, and .53 for the linear autoregressive model, linear autoregressive model with a synchronization component, the nonlinear autoregressive model, and the nonlinear autoregressive model with a synchronization component, respectively. All models were more accurate at a lag of 20 sec compared to 50 sec or customized lag lengths. Although the linear models were more accurate overall, the nonlinear synchronization parameters were more often related to psychological variables and performance. In particular, greater synchronization was observed with the nonlinear model when the target event rate increased, compared to when it decreased, which was expected from the general theory of synchronization. Nonlinear models were also more effective for uncovering inhibitory or dampening relationships between the co-workers as well as mutually excitatory relationships. Future research should explore the comparative model results for tasks that induce higher levels of synchronization and involve different types of internal group coordination.

  10. Model for improved correlation of BMD values between abdominal routine Dual energy CT data and DXA scans.

    Science.gov (United States)

    Woisetschläger, Mischa; Spångeus, Anna

    2018-02-01

    Osteoporosis is a common but underdiagnosed and undertreated disease causing severe morbidity and economic burden. The gold standard for detection of osteoporosis is DXA (dual energy x-ray absorptiometry), which is a dedicated examination for osteoporosis. Dual energy CT (DECT) examinations are increasingly used in daily routine for a wide variety of diagnoses. In the present study, we wanted to examine whether vBMD (volume bone mass density) could be evaluated as a side product in non-contrast as well as contrast phases as well as to evaluate a correction model taking known shortcomings for DXA into account. A total of 20 patients, i.e. 79 vertebrae (one excluded due to vertebral fracture), mean age 71 years (range 43-85) with a mean BMI (body mass index) of 26 (range 17-33) were examined with both abdominal/pelvic DECT as well as DXA. Furthermore, aortic calcium was measured as well as the presence of osteoarthritis of the spine (OAS) and osteoarthritis in facet joints (OAF) with a 5-grade scaling system. A significant correlation was found between DXA BMD and vBMD from DECT with no contrast (WNC) (r = 0.424, p = 0.001), and with venous contrast (WVC) (r = 0.402, p < 0.001), but no significant correlation was found with arterial contrast (WAC). Using multivariate linear regression with DXA BMD as dependent, two models were created combining DECT WNC, aortic calciumscore (ACS), OAS and BMI yielding an R 2  = 0.616 (model 1) and replacement of WNC to WVC a R 2  = 0.612 (model 2). The Pearson correlation between DXA and predictive DXA BMD value of model 1 was r = 0.785 (p < 0.001) and model 2 r = 0.782 (p < 0.001). There is a correlation between DXA BMD and DECT in non-contrast and venous contrast scans but not in arterial scans. The correlation is further improved by quantifying the degree of different confounding factors (osteoarthritis of the spine, body mass index and aortic calcium score) and taking these into account in

  11. Heat transport in two-dimensional materials by directly solving the phonon Boltzmann equation under Callaway's dual relaxation model

    Science.gov (United States)

    Guo, Yangyu; Wang, Moran

    2017-10-01

    The single mode relaxation time approximation has been demonstrated to greatly underestimate the lattice thermal conductivity of two-dimensional materials due to the collective effect of phonon normal scattering. Callaway's dual relaxation model represents a good approximation to the otherwise ab initio solution of the phonon Boltzmann equation. In this work we develop a discrete-ordinate-method (DOM) scheme for the numerical solution of the phonon Boltzmann equation under Callaway's model. Heat transport in a graphene ribbon with different geometries is modeled by our scheme, which produces results quite consistent with the available molecular dynamics, Monte Carlo simulations, and experimental measurements. Callaway's lattice thermal conductivity model with empirical boundary scattering rates is examined and shown to overestimate or underestimate the direct DOM solution. The length convergence of the lattice thermal conductivity of a rectangular graphene ribbon is explored and found to depend appreciably on the ribbon width, with a semiquantitative correlation provided between the convergence length and the width. Finally, we predict the existence of a phonon Knudsen minimum in a graphene ribbon only at a low system temperature and isotope concentration so that the average normal scattering rate is two orders of magnitude stronger than the intrinsic resistive one. The present work will promote not only the methodology for the solution of the phonon Boltzmann equation but also the theoretical modeling and experimental detection of hydrodynamic phonon transport in two-dimensional materials.

  12. On modelling of shear fracture in deep drawing of a high-strength dual-phase sheet steel

    Science.gov (United States)

    Behrens, B.-A.; Bonk, C.; Peshekhodov, I.

    2017-09-01

    The paper presents application of fracture behaviour characterisation results of a dual-phase sheet steel DP600 to an FEA of its deep-drawing for shear fracture prediction. The characterisation results were obtained with the help of a characterisation method based on a tensile test on a novel butterfly specimen and published previously by the authors. The aim of the present paper is to evaluate that characterisation method on a deep-drawing process. Based on the previous results of the authors, the fracture behaviour is modelled here with the help of the modified Mohr-Coloumb fracture model. The obtained FEA results reveal that shear fracture of the studied material is predicted too early by the used MMC fracture model. A novel adjustment of the model is proposed yielding infinitely high fracture strains at strongly pressure-superimposed stress states. As it is often the case in the state-of-the-art fracture characterisation of high-strenght sheet steels, such stress states were not tested during the previously performed fracture characterisation but occur during the studied deep drawing process. With the help of the adjusted MMC fracture model, it is possible to predict the crack initiation moment very accurately and the crack initiation location sufficiently accurately.

  13. Multiple player tracking in sports video: a dual-mode two-way bayesian inference approach with progressive observation modeling.

    Science.gov (United States)

    Xing, Junliang; Ai, Haizhou; Liu, Liwei; Lao, Shihong

    2011-06-01

    Multiple object tracking (MOT) is a very challenging task yet of fundamental importance for many practical applications. In this paper, we focus on the problem of tracking multiple players in sports video which is even more difficult due to the abrupt movements of players and their complex interactions. To handle the difficulties in this problem, we present a new MOT algorithm which contributes both in the observation modeling level and in the tracking strategy level. For the observation modeling, we develop a progressive observation modeling process that is able to provide strong tracking observations and greatly facilitate the tracking task. For the tracking strategy, we propose a dual-mode two-way Bayesian inference approach which dynamically switches between an offline general model and an online dedicated model to deal with single isolated object tracking and multiple occluded object tracking integrally by forward filtering and backward smoothing. Extensive experiments on different kinds of sports videos, including football, basketball, as well as hockey, demonstrate the effectiveness and efficiency of the proposed method.

  14. Matching ERS scatterometer based soil moisture patterns with simulations of a conceptual dual layer hydrologic model over Austria

    Directory of Open Access Journals (Sweden)

    J. Parajka

    2009-02-01

    Full Text Available This study compares ERS scatterometer top soil moisture observations with simulations of a dual layer conceptual hydrologic model. The comparison is performed for 148 Austrian catchments in the period 1991–2000. On average, about 5 to 7 scatterometer images per month with a mean spatial coverage of about 37% are available. The results indicate that the agreement between the two top soil moisture estimates changes with the season and the weight given to the scatterometer in hydrologic model calibration. The hydrologic model generally simulates larger top soil moisture values than are observed by the scatterometer. The differences tend to be smaller for lower altitudes and the winter season. The average correlation between the two estimates is more than 0.5 in the period from July to October, and about 0.2 in the winter months, depending on the period and calibration setting. Using both ERS scatterometer based soil moisture and runoff for model calibration provides more robust model parameters than using either of these two sources of information.

  15. Matching ERS scatterometer based soil moisture patterns with simulations of a conceptual dual layer hydrologic model over Austria

    Science.gov (United States)

    Parajka, J.; Naeimi, V.; Blöschl, G.; Komma, J.

    2009-02-01

    This study compares ERS scatterometer top soil moisture observations with simulations of a dual layer conceptual hydrologic model. The comparison is performed for 148 Austrian catchments in the period 1991-2000. On average, about 5 to 7 scatterometer images per month with a mean spatial coverage of about 37% are available. The results indicate that the agreement between the two top soil moisture estimates changes with the season and the weight given to the scatterometer in hydrologic model calibration. The hydrologic model generally simulates larger top soil moisture values than are observed by the scatterometer. The differences tend to be smaller for lower altitudes and the winter season. The average correlation between the two estimates is more than 0.5 in the period from July to October, and about 0.2 in the winter months, depending on the period and calibration setting. Using both ERS scatterometer based soil moisture and runoff for model calibration provides more robust model parameters than using either of these two sources of information.

  16. A Functional Near-Infrared Spectroscopy Study of Lexical Decision Task Supports the Dual Route Model and the Phonological Deficit Theory of Dyslexia

    Science.gov (United States)

    Sela, Itamar; Izzetoglu, Meltem; Izzetoglu, Kurtulus; Onaral, Banu

    2014-01-01

    The dual route model (DRM) of reading suggests two routes of reading development: the phonological and the orthographic routes. It was proposed that although the two routes are active in the process of reading; the first is more involved at the initial stages of reading acquisition, whereas the latter needs more reading training to mature. A…

  17. Analytical drain current model for symmetric dual-gate amorphous indium gallium zinc oxide thin-film transistors

    Science.gov (United States)

    Qin, Ting; Liao, Congwei; Huang, Shengxiang; Yu, Tianbao; Deng, Lianwen

    2018-01-01

    An analytical drain current model based on the surface potential is proposed for amorphous indium gallium zinc oxide (a-InGaZnO) thin-film transistors (TFTs) with a synchronized symmetric dual-gate (DG) structure. Solving the electric field, surface potential (φS), and central potential (φ0) of the InGaZnO film using the Poisson equation with the Gaussian method and Lambert function is demonstrated in detail. The compact analytical model of current–voltage behavior, which consists of drift and diffusion components, is investigated by regional integration, and voltage-dependent effective mobility is taken into account. Comparison results demonstrate that the calculation results obtained using the derived models match well with the simulation results obtained using a technology computer-aided design (TCAD) tool. Furthermore, the proposed model is incorporated into SPICE simulations using Verilog-A to verify the feasibility of using DG InGaZnO TFTs for high-performance circuit designs.

  18. Multilevel spatio-temporal dual changepoint models for relating alcohol outlet destruction and changes in neighbourhood rates of assaultive violence

    Directory of Open Access Journals (Sweden)

    Qingzhao Yu

    2008-05-01

    Full Text Available Many previous studies have suggested a link between alcohol outlets and assaultive violence. In this paper, we evaluate the impact of the “1992 Civil Unrest” in Los Angeles (which followed the “Rodney King incident”, in which many alcohol outlets were damaged leading to a decrease in alcohol outlet density, on crime. We leverage the natural experiment created by the closure of alcohol outlets in certain areas and not others to explore the effects of alcohol availability on assault crimes at the census tract level. We develop a hierarchical model that controls for important covariates (such as race and socio-economic status and accounts for unexplained spatial and temporal variability. While our model is somewhat complex, its hierarchical Bayesian analysis is accessible via the WinBUGS software. Our results show that, keeping other effects fixed, the reduction in alcohol availability within a census tract was associated with a drop in the assaultive violence rate at the census tract level. Comparing several dual candidate changepoint models using the Deviance Information Criterion, the drop in assaultive violence rate is best seen as having occurred one year after the reduction in alcohol availability, with the effect lasting roughly five years. We also create maps of the fitted assault rates in Los Angeles, as well as spatial residual maps that suggest various spatially-varying covariates are still missing from our model.

  19. Validation of a zero-dimensional and 2-phase combustion model for dual-fuel compression ignition engine simulation

    Directory of Open Access Journals (Sweden)

    Mikulski Maciej

    2017-01-01

    Full Text Available Increasing demands for the reduction of exhaust emissions and the pursuit to re-duce the use of fossil fuels require the search for new fuelling technologies in combustion engines. One of the most promising technologies is the multi-fuel compression ignition engine concept, in which a small dose of liquid fuel injected directly into the cylinder acts as the ignition inhibitor of the gaseous fuel. Achieving the optimum combustion process in such an engine requires the application of advanced control algorithms which require mathematical modelling support. In response to the growing demand for new simulation tools, a 0-D model of a dual-fuel engine was proposed and validated. The validation was performed in a broad range of engine operating points, including various speeds and load condition, as well as different natural gas/diesel blend ratios. It was demonstrated that the average model calculation error within the entire cycle did not exceed 6.2%, and was comparable to the measurement results cycle to cycle variations. The maximum model calculation error in a single point of a cycle was 15% for one of the complex (multipoint injection cases. In other cases, it did not exceed 11%.

  20. The Explicit Determinations Of Dual Plane Curves And Dual Helices In Terms Of Its Dual Curvature And Dual Torsion

    OpenAIRE

    Lee Jae Won; Choi Jin Ho; Jin Dae Ho

    2014-01-01

    In this paper, we give the explicit determinations of dual plane curves, general dual helices and dual slant helices in terms of its dual curvature and dual torsion as a fundamental theory of dual curves in a dual 3-space

  1. Dual energy computed tomography thermometry during hepatic microwave ablation in an ex-vivo porcine model.

    Science.gov (United States)

    Paul, Jijo; Vogl, Thomas J; Chacko, Annamma

    2015-11-01

    Microwave thermoablation (MTA) is a treatment method used to destroy hepatic tumors. To investigate temperature changes during MTA of ex-vivo porcine liver using dual-energy computed tomography (DECT) imaging. Three MTA experiments were performed using ex-vivo porcine liver (15 × 15 × 15 cm(3)) and DECT imaging with 80/Sn140 kVp spectral and 0.5-weighted reconstructions. Images were acquired from basic organ temperature to 100 °C with 10 °C difference during microwave heating and cooling phases. Three fluoro-optic thermometers were used for temperature measurements; two were placed at 1 cm and third one positioned at 2 cm distance from the applicator. Tissue temperature, ablation-region-conspicuity (ARC), ablation-region dimensions and image quality were determined. Regression analysis was performed determining thermal sensitivity during heating and cooling phases. Determined thermal sensitivities during heating phase were: -0.59 Hounsfield Unit/°C (80 kVp), -0.60HU/°C (0.5-weighted) and -0.59HU/°C (140 kVp); furthermore, during cooling: -0.56HU/°C (80 kVp), -0.55HU/°C (0.5-weighted) and -0.55HU/°C (140 kVp). ARC showed significantly higher (all P 0.05). Signal-to-noise ratios were higher for 0.5-weighted but ARC values were higher for 80 kVp images. Microwave thermal sensitivity on tissue was inversely linear with DECT image datasets. Heating phase showed higher influence of temperature on HU compared to cooling; ARC and ablation-region were increased with increase in temperature. Copyright © 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  2. Monte Carlo Modeling of Dual and Triple Photon Energy Absorptiometry Technique

    Directory of Open Access Journals (Sweden)

    Alireza Kamali-Asl

    2007-12-01

    Full Text Available Introduction: Osteoporosis is a bone disease in which there is a reduction in the amount of bone mineral content leading to an increase in the risk of bone fractures. The affected individuals not only have to go through lots of pain and suffering but this disease also results in high economic costs to the society due to a large number of fractures.  A timely and accurate diagnosis of this disease makes it possible to start a treatment and thus preventing bone fractures as a result of osteoporosis. Radiographic methods are particularly well suited for in vivo determination of bone mineral density (BMD due to the relatively high x-ray absorption properties of bone mineral compared to other tissues. Materials and Methods: Monte Carlo simulation has been conducted to explore the possibilities of triple photon energy absorptiometry (TPA in the measurement of bone mineral content. The purpose of this technique is to correctly measure the bone mineral density in the presence of fatty and soft tissues. The same simulations have been done for a dual photon energy absorptiometry (DPA system and an extended DPA system. Results: Using DPA with three components improves the accuracy of the obtained result while the simulation results show that TPA system is not accurate enough to be considered as an adequate method for the measurement of bone mineral density. Discussion: The reason for the improvement in the accuracy is the consideration of fatty tissue in TPA method while having attenuation coefficient as a function of energy makes TPA an inadequate method. Conclusion: Using TPA method is not a perfect solution to overcome the problem of non uniformity in the distribution of fatty tissue.

  3. Uncovering Listeria monocytogenes hypervirulence by harnessing its biodiversity

    Science.gov (United States)

    Charlier, Caroline; Touchon, Marie; Chenal-Francisque, Viviane; Leclercq, Alexandre; Criscuolo, Alexis; Gaultier, Charlotte; Roussel, Sophie; Brisabois, Anne; Disson, Olivier; Rocha, Eduardo P. C.; Brisse, Sylvain; Lecuit, Marc

    2016-01-01

    Microbial pathogenesis studies are typically performed with reference strains, thereby overlooking microbial intra-species virulence heterogeneity. Here we integrated human epidemiological and clinical data with bacterial population genomics to harness the biodiversity of the model foodborne pathogen Listeria monocytogenes and decipher the basis of its neural and placental tropisms. Taking advantage of the clonal structure of this bacterial species, we identify clones epidemiologically associated with either food or human central nervous system (CNS) and maternal-neonatal (MN) listeriosis. The latter are also most prevalent in patients without immunosuppressive comorbidities. Strikingly, CNS and MN clones are hypervirulent in a humanized mouse model of listeriosis. By integrating epidemiological data and comparative genomics, we uncovered multiple novel putative virulence factors and demonstrated experimentally the contribution of the first gene cluster mediating Listeria monocytogenes neural and placental tropisms. This study illustrates the exceptional power of harnessing microbial biodiversity to identify clinically relevant microbial virulence attributes. PMID:26829754

  4. Uncovering Listeria monocytogenes hypervirulence by harnessing its biodiversity.

    Science.gov (United States)

    Maury, Mylène M; Tsai, Yu-Huan; Charlier, Caroline; Touchon, Marie; Chenal-Francisque, Viviane; Leclercq, Alexandre; Criscuolo, Alexis; Gaultier, Charlotte; Roussel, Sophie; Brisabois, Anne; Disson, Olivier; Rocha, Eduardo P C; Brisse, Sylvain; Lecuit, Marc

    2016-03-01

    Microbial pathogenesis studies are typically performed with reference strains, thereby overlooking within-species heterogeneity in microbial virulence. Here we integrated human epidemiological and clinical data with bacterial population genomics to harness the biodiversity of the model foodborne pathogen Listeria monocytogenes and decipher the basis of its neural and placental tropisms. Taking advantage of the clonal structure of this bacterial species, we identify clones epidemiologically associated either with food or with human central nervous system (CNS) or maternal-neonatal (MN) listeriosis. The latter clones are also most prevalent in patients without immunosuppressive comorbidities. Strikingly, CNS- and MN-associated clones are hypervirulent in a humanized mouse model of listeriosis. By integrating epidemiological data and comparative genomics, we have uncovered multiple new putative virulence factors and demonstrate experimentally the contribution of the first gene cluster mediating L. monocytogenes neural and placental tropisms. This study illustrates the exceptional power in harnessing microbial biodiversity to identify clinically relevant microbial virulence attributes.

  5. Antifibrotic Effects of the Dual CCR2/CCR5 Antagonist Cenicriviroc in Animal Models of Liver and Kidney Fibrosis.

    Directory of Open Access Journals (Sweden)

    Eric Lefebvre

    Full Text Available Interactions between C-C chemokine receptor types 2 (CCR2 and 5 (CCR5 and their ligands, including CCL2 and CCL5, mediate fibrogenesis by promoting monocyte/macrophage recruitment and tissue infiltration, as well as hepatic stellate cell activation. Cenicriviroc (CVC is an oral, dual CCR2/CCR5 antagonist with nanomolar potency against both receptors. CVC's anti-inflammatory and antifibrotic effects were evaluated in a range of preclinical models of inflammation and fibrosis.Monocyte/macrophage recruitment was assessed in vivo in a mouse model of thioglycollate-induced peritonitis. CCL2-induced chemotaxis was evaluated ex vivo on mouse monocytes. CVC's antifibrotic effects were evaluated in a thioacetamide-induced rat model of liver fibrosis and mouse models of diet-induced non-alcoholic steatohepatitis (NASH and renal fibrosis. Study assessments included body and liver/kidney weight, liver function test, liver/kidney morphology and collagen deposition, fibrogenic gene and protein expression, and pharmacokinetic analyses.CVC significantly reduced monocyte/macrophage recruitment in vivo at doses ≥20 mg/kg/day (p < 0.05. At these doses, CVC showed antifibrotic effects, with significant reductions in collagen deposition (p < 0.05, and collagen type 1 protein and mRNA expression across the three animal models of fibrosis. In the NASH model, CVC significantly reduced the non-alcoholic fatty liver disease activity score (p < 0.05 vs. controls. CVC treatment had no notable effect on body or liver/kidney weight.CVC displayed potent anti-inflammatory and antifibrotic activity in a range of animal fibrosis models, supporting human testing for fibrotic diseases. Further experimental studies are needed to clarify the underlying mechanisms of CVC's antifibrotic effects. A Phase 2b study in adults with NASH and liver fibrosis is fully enrolled (CENTAUR Study 652-2-203; NCT02217475.

  6. Coupling X-band dual-polarized mini-radars and hydro-meteorological forecast models: the HYDRORAD project

    Directory of Open Access Journals (Sweden)

    E. Picciotti

    2013-05-01

    Full Text Available Hydro-meteorological hazards like convective outbreaks leading to torrential rain and floods are among the most critical environmental issues world-wide. In that context weather radar observations have proven to be very useful in providing information on the spatial distribution of rainfall that can support early warning of floods. However, quantitative precipitation estimation by radar is subjected to many limitations and uncertainties. The use of dual-polarization at high frequency (i.e. X-band has proven particularly useful for mitigating some of the limitation of operational systems, by exploiting the benefit of easiness to transport and deploy and the high spatial and temporal resolution achievable at small antenna sizes. New developments on X-band dual-polarization technology in recent years have received the interest of scientific and operational communities in these systems. New enterprises are focusing on the advancement of cost-efficient mini-radar network technology, based on high-frequency (mainly X-band and low-power weather radar systems for weather monitoring and hydro-meteorological forecasting. Within the above context, the main objective of the HYDRORAD project was the development of an innovative mbox{integrated} decision support tool for weather monitoring and hydro-meteorological applications. The integrated system tool is based on a polarimetric X-band mini-radar network which is the core of the decision support tool, a novel radar products generator and a hydro-meteorological forecast modelling system that ingests mini-radar rainfall products to forecast precipitation and floods. The radar products generator includes algorithms for attenuation correction, hydrometeor classification, a vertical profile reflectivity correction, a new polarimetric rainfall estimators developed for mini-radar observations, and short-term nowcasting of convective cells. The hydro-meteorological modelling system includes the Mesoscale Model 5

  7. Tomography of atomic number and density of materials using dual-energy imaging and the Alvarez and Macovski attenuation model

    International Nuclear Information System (INIS)

    Paziresh, M.; Kingston, A. M.; Latham, S. J.; Fullagar, W. K.; Myers, G. M.

    2016-01-01

    Dual-energy computed tomography and the Alvarez and Macovski [Phys. Med. Biol. 21, 733 (1976)] transmitted intensity (AMTI) model were used in this study to estimate the maps of density (ρ) and atomic number (Z) of mineralogical samples. In this method, the attenuation coefficients are represented [Alvarez and Macovski, Phys. Med. Biol. 21, 733 (1976)] in the form of the two most important interactions of X-rays with atoms that is, photoelectric absorption (PE) and Compton scattering (CS). This enables material discrimination as PE and CS are, respectively, dependent on the atomic number (Z) and density (ρ) of materials [Alvarez and Macovski, Phys. Med. Biol. 21, 733 (1976)]. Dual-energy imaging is able to identify sample materials even if the materials have similar attenuation coefficients at single-energy spectrum. We use the full model rather than applying one of several applied simplified forms [Alvarez and Macovski, Phys. Med. Biol. 21, 733 (1976); Siddiqui et al., SPE Annual Technical Conference and Exhibition (Society of Petroleum Engineers, 2004); Derzhi, U.S. patent application 13/527,660 (2012); Heismann et al., J. Appl. Phys. 94, 2073–2079 (2003); Park and Kim, J. Korean Phys. Soc. 59, 2709 (2011); Abudurexiti et al., Radiol. Phys. Technol. 3, 127–135 (2010); and Kaewkhao et al., J. Quant. Spectrosc. Radiat. Transfer 109, 1260–1265 (2008)]. This paper describes the tomographic reconstruction of ρ and Z maps of mineralogical samples using the AMTI model. The full model requires precise knowledge of the X-ray energy spectra and calibration of PE and CS constants and exponents of atomic number and energy that were estimated based on fits to simulations and calibration measurements. The estimated ρ and Z images of the samples used in this paper yield average relative errors of 2.62% and 1.19% and maximum relative errors of 2.64% and 7.85%, respectively. Furthermore, we demonstrate that the method accounts for the beam hardening effect in density (

  8. Coupling X-band dual-polarized mini-radars and hydro-meteorological forecast models: the HYDRORAD project

    Science.gov (United States)

    Picciotti, E.; Marzano, F. S.; Anagnostou, E. N.; Kalogiros, J.; Fessas, Y.; Volpi, A.; Cazac, V.; Pace, R.; Cinque, G.; Bernardini, L.; De Sanctis, K.; Di Fabio, S.; Montopoli, M.; Anagnostou, M. N.; Telleschi, A.; Dimitriou, E.; Stella, J.

    2013-05-01

    Hydro-meteorological hazards like convective outbreaks leading to torrential rain and floods are among the most critical environmental issues world-wide. In that context weather radar observations have proven to be very useful in providing information on the spatial distribution of rainfall that can support early warning of floods. However, quantitative precipitation estimation by radar is subjected to many limitations and uncertainties. The use of dual-polarization at high frequency (i.e. X-band) has proven particularly useful for mitigating some of the limitation of operational systems, by exploiting the benefit of easiness to transport and deploy and the high spatial and temporal resolution achievable at small antenna sizes. New developments on X-band dual-polarization technology in recent years have received the interest of scientific and operational communities in these systems. New enterprises are focusing on the advancement of cost-efficient mini-radar network technology, based on high-frequency (mainly X-band) and low-power weather radar systems for weather monitoring and hydro-meteorological forecasting. Within the above context, the main objective of the HYDRORAD project was the development of an innovative integrated decision support tool for weather monitoring and hydro-meteorological applications. The integrated system tool is based on a polarimetric X-band mini-radar network which is the core of the decision support tool, a novel radar products generator and a hydro-meteorological forecast modelling system that ingests mini-radar rainfall products to forecast precipitation and floods. The radar products generator includes algorithms for attenuation correction, hydrometeor classification, a vertical profile reflectivity correction, a new polarimetric rainfall estimators developed for mini-radar observations, and short-term nowcasting of convective cells. The hydro-meteorological modelling system includes the Mesoscale Model 5 (MM5) and the Army Corps

  9. Numerical simulation of time fractional dual-phase-lag model of heat transfer within skin tissue during thermal therapy.

    Science.gov (United States)

    Kumar, Dinesh; Rai, K N

    2017-07-01

    In this paper, we investigated the thermal behavior in living biological tissues using time fractional dual-phase-lag bioheat transfer (DPLBHT) model subjected to Dirichelt boundary condition in presence of metabolic and electromagnetic heat sources during thermal therapy. We solved this bioheat transfer model using finite element Legendre wavelet Galerkin method (FELWGM) with help of block pulse function in sense of Caputo fractional order derivative. We compared the obtained results from FELWGM and exact method in a specific case, and found a high accuracy. Results are interpreted in the form of standard and anomalous cases for taking different order of time fractional DPLBHT model. The time to achieve hyperthermia position is discussed in both cases as standard and time fractional order derivative. The success of thermal therapy in the treatment of metastatic cancerous cell depends on time fractional order derivative to precise prediction and control of temperature. The effect of variability of parameters such as time fractional derivative, lagging times, blood perfusion coefficient, metabolic heat source and transmitted power on dimensionless temperature distribution in skin tissue is discussed in detail. The physiological parameters has been estimated, corresponding to the value of fractional order derivative for hyperthermia treatment therapy. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Correspondence between theoretical models and dual energy x-ray absorptiometry measurements of femoral cross-sectional growth during adolescence

    Science.gov (United States)

    van der Meulen, M. C.; Marcus, R.; Bachrach, L. K.; Carter, D. R.

    1997-01-01

    We have developed an analytical model of long bone cross-sectional ontogeny in which appositional growth of the diaphysis is primarily driven by mechanical stimuli associated with increasing body mass during growth and development. In this study, our goal was to compare theoretical predictions of femoral diaphyseal structure from this model with measurements of femoral bone mineral and geometry by dual energy x-ray absorptiometry. Measurements of mid-diaphyseal femoral geometry and structure were made previously in 101 Caucasian adolescents and young adults 9-26 years of age. The data on measured bone mineral content and calculated section modulus were compared with the results of our analytical model of cross-sectional development of the human femur over the same age range. Both bone mineral content and section modulus showed good correspondence with experimental measurements when the relationships with age and body mass were examined. Strong linear relationships were evident for both parameters when examined as a function of body mass.

  11. Comparison of Prediction Models for a Dual-Hormone Artificial Pancreas

    DEFF Research Database (Denmark)

    Boiroux, Dimitri; Bátora, Vladimír; Hagdrup, Morten

    2015-01-01

    In this paper we compare the performance of five different continuous time transfer function models used in closed-loop model predictive control (MPC). These models describe the glucose-insulin and glucose-glucagon dynamics. They are discretized into a state-space description and used as predicti...... order model without delay should provide the best trade-off between sensitivity to uncertainties and practical usability for in vivo clinical studies....

  12. Dual estimation : Constructing building energy models from data sampled at low rate

    NARCIS (Netherlands)

    Baldi, S.; Yuan, S.; Endel, P; Holub, O.

    2016-01-01

    Estimation of energy models from data is an important part of advanced fault detection and diagnosis tools for smart energy purposes. Estimated energy models can be used for a large variety of management and control tasks, spanning from model predictive building control to estimation of energy

  13. Modeling Parallelization and Flexibility Improvements in Skill Acquisition: From Dual Tasks to Complex Dynamic Skills

    Science.gov (United States)

    Taatgen, Niels

    2005-01-01

    Emerging parallel processing and increased flexibility during the acquisition of cognitive skills form a combination that is hard to reconcile with rule-based models that often produce brittle behavior. Rule-based models can exhibit these properties by adhering to 2 principles: that the model gradually learns task-specific rules from instructions…

  14. Dual symmetry in gauge theories

    International Nuclear Information System (INIS)

    Koshkarov, A.L.

    1997-01-01

    Continuous dual symmetry in electrodynamics, Yang-Mills theory and gravitation is investigated. Dual invariant which leads to badly nonlinear motion equations is chosen as a Lagrangian of the pure classical dual nonlinear electrodynamics. In a natural manner some dual angle which is determined by the electromagnetic strengths at the point of the time-space appears in the model. Motion equations may well be interpreted as the equations of the standard Maxwell theory with source. Alternative interpretation is the quasi-Maxwell linear theory with magnetic charge. Analogous approach is possible in the Yang-Mills theory. In this case the dual-invariant non-Abelian theory motion equations possess the same instanton solutions as the conventional Yang-Mills equations have. An Abelian two-parameter dual group is found to exist in gravitation. Irreducible representations have been obtained: the curvature tensor was expanded into the sum of twice anti-self-dual and self-dual parts. Gravitational instantons are defined as (real )solutions to the usual duality equations. Central symmetry solutions to these equations are obtained. The twice anti-self-dual part of the curvature tensor may be used for introduction of new gravitational equations generalizing Einstein''s equations. However, the theory obtained reduces to the conformal-flat Nordstroem theory

  15. Dual-component model of respiratory motion based on the periodic autoregressive moving average (periodic ARMA) method

    International Nuclear Information System (INIS)

    McCall, K C; Jeraj, R

    2007-01-01

    A new approach to the problem of modelling and predicting respiration motion has been implemented. This is a dual-component model, which describes the respiration motion as a non-periodic time series superimposed onto a periodic waveform. A periodic autoregressive moving average algorithm has been used to define a mathematical model of the periodic and non-periodic components of the respiration motion. The periodic components of the motion were found by projecting multiple inhale-exhale cycles onto a common subspace. The component of the respiration signal that is left after removing this periodicity is a partially autocorrelated time series and was modelled as an autoregressive moving average (ARMA) process. The accuracy of the periodic ARMA model with respect to fluctuation in amplitude and variation in length of cycles has been assessed. A respiration phantom was developed to simulate the inter-cycle variations seen in free-breathing and coached respiration patterns. At ±14% variability in cycle length and maximum amplitude of motion, the prediction errors were 4.8% of the total motion extent for a 0.5 s ahead prediction, and 9.4% at 1.0 s lag. The prediction errors increased to 11.6% at 0.5 s and 21.6% at 1.0 s when the respiration pattern had ±34% variations in both these parameters. Our results have shown that the accuracy of the periodic ARMA model is more strongly dependent on the variations in cycle length than the amplitude of the respiration cycles

  16. COMPARISON OF EXPERIMENTS TO CFD MODELS FOR MIXING USING DUAL OPPOSING JETS IN TANKS WITH AND WITHOUT INTERNAL OBSTRUCTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Leishear, R.; Poirier, M.; Lee, S.; Fowley, M.

    2012-06-26

    This paper documents testing methods, statistical data analysis, and a comparison of experimental results to CFD models for blending of fluids, which were blended using a single pump designed with dual opposing nozzles in an eight foot diameter tank. Overall, this research presents new findings in the field of mixing research. Specifically, blending processes were clearly shown to have random, chaotic effects, where possible causal factors such as turbulence, pump fluctuations, and eddies required future evaluation. CFD models were shown to provide reasonable estimates for the average blending times, but large variations -- or scatter -- occurred for blending times during similar tests. Using this experimental blending time data, the chaotic nature of blending was demonstrated and the variability of blending times with respect to average blending times were shown to increase with system complexity. Prior to this research, the variation in blending times caused discrepancies between CFD models and experiments. This research addressed this discrepancy, and determined statistical correction factors that can be applied to CFD models, and thereby quantified techniques to permit the application of CFD models to complex systems, such as blending. These blending time correction factors for CFD models are comparable to safety factors used in structural design, and compensate variability that cannot be theoretically calculated. To determine these correction factors, research was performed to investigate blending, using a pump with dual opposing jets which re-circulate fluids in the tank to promote blending when fluids are added to the tank. In all, eighty-five tests were performed both in a tank without internal obstructions and a tank with vertical obstructions similar to a tube bank in a heat exchanger. These obstructions provided scale models of vertical cooling coils below the liquid surface for a full scale, liquid radioactive waste storage tank. Also, different jet

  17. Dual Enrollment for High School Students

    Science.gov (United States)

    Edwards, Linsey; Hughes, Katherine

    2011-01-01

    Dual enrollment programs allow high school students to enroll in college courses and potentially earn college credit. The term concurrent enrollment is sometimes used interchangeably with dual enrollment, and sometimes to refer to a particular model of dual enrollment. In some programs, students earn high school and college credit simultaneously;…

  18. The effect of body dissatisfaction on eating disorder symptomatology : mediating effects of depression and low self-esteem : a partial test of the Dual-Pathway Model

    OpenAIRE

    Jonstang, Ida Cecilie

    2009-01-01

    Aim. The present study is based on the dual-pathway model (Stice, 2001), specifically testing the negative affect pathway of this model. This study examined whether depression and low self-esteem separately mediate the relationship between body dissatisfaction and general eating disorder symptomatology, focusing primarily on restraint eating and bulimic symptoms. Method. A sample of 113 junior high-school boys and girls completed measures of body dissatisfaction, self-esteem, depression,...

  19. Comparison of model and human observer performance for detection and discrimination tasks using dual-energy x-ray images

    International Nuclear Information System (INIS)

    Richard, Samuel; Siewerdsen, Jeffrey H.

    2008-01-01

    Model observer performance, computed theoretically using cascaded systems analysis (CSA), was compared to the performance of human observers in detection and discrimination tasks. Dual-energy (DE) imaging provided a wide range of acquisition and decomposition parameters for which observer performance could be predicted and measured. This work combined previously derived observer models (e.g., Fisher-Hotelling and non-prewhitening) with CSA modeling of the DE image noise-equivalent quanta (NEQ) and imaging task (e.g., sphere detection, shape discrimination, and texture discrimination) to yield theoretical predictions of detectability index (d ' ) and area under the receiver operating characteristic (A Z ). Theoretical predictions were compared to human observer performance assessed using 9-alternative forced-choice tests to yield measurement of A Z as a function of DE image acquisition parameters (viz., allocation of dose between the low- and high-energy images) and decomposition technique [viz., three DE image decomposition algorithms: standard log subtraction (SLS), simple-smoothing of the high-energy image (SSH), and anti-correlated noise reduction (ACNR)]. Results showed good agreement between theory and measurements over a broad range of imaging conditions. The incorporation of an eye filter and internal noise in the observer models demonstrated improved correspondence with human observer performance. Optimal acquisition and decomposition parameters were shown to depend on the imaging task; for example, ACNR and SSH yielded the greatest performance in the detection of soft-tissue and bony lesions, respectively. This study provides encouraging evidence that Fourier-based modeling of NEQ computed via CSA and imaging task provides a good approximation to human observer performance for simple imaging tasks, helping to bridge the gap between Fourier metrics of detector performance (e.g., NEQ) and human observer performance.

  20. Examining a Dual-Process Model of Desensitization and Hypersensitization to Community Violence in African American Male Adolescents.

    Science.gov (United States)

    Gaylord-Harden, Noni K; Bai, Grace J; Simic, Dusan

    2017-10-01

    The purpose of the current study was to examine a dual-process model of reactivity to community violence exposure in African American male adolescents from urban communities. The model focused on desensitization and hypersensitization effects as well as desensitization and hypersensitization as predictors of aggressive behavior. Participants were 133 African American male high school students, mean age = 15.17 years, SD = 0.96. Participants completed measures of exposure to community violence, depressive symptoms, hyperarousal symptoms, aggressive beliefs, and aggressive behaviors at two time points. Community violence exposure predicted changes in aggression, β = .25, p = .004, and physiological arousal, β = .22, p = .010, over time, but not aggressive beliefs. The curvilinear association between community violence exposure and changes in depression over time was not significant, β = .42, p = .083, but there was a significant linear association between the exposure to community violence (ECV) and changes in levels of depression over time, β = .21, p = .014. Results indicated a significant mediation effect for hyperarousal on the association between community violence exposure and aggressive behavior, B = 0.20, 95% CI = [0.04, 0.54]. Results showed support for physiological hypersensitization, with hypersensitization increasing the risk for aggressive behavior. Copyright © 2017 International Society for Traumatic Stress Studies.

  1. Dual Substituent Parameter Modeling of Theoretical, NMR and IR Spectral Data of 5-Substituted Indole-2,3-diones

    Directory of Open Access Journals (Sweden)

    Zora Šusteková

    2002-11-01

    Full Text Available Correlations of AM1 and PM3 theoretical data, 13C-NMR substituent chemical shifts (13C-SCS and IR carbonyl group wave numbers [ν(C3═O] were studied using dual substituent parameter (DSP models for 5-substituted indole-2,3-diones. For the C7 atom a reverse substituent effect attributed to extended π-polarization was observed. On the other hand, the DSP approaches for the C3 atom showed normal substituent effects with some contribution of reverse effect supported strongly by 13C-SCS correlations. In the ν(C3═O and p(C3═O DSP correlations the field effect contribution predominates over the resonance effect, which justifies the using of earlier suggested vibrational coupling (V-C model for 5- and 6-substituted indole-2,3-diones.

  2. Phase transitions in self-dual generalizations of the Baxter-Wu model

    NARCIS (Netherlands)

    Deng, Y.; Guo, W.; Heringa, J.R.; Blöte, H.W.J.; Nienhuis, B.

    2010-01-01

    We study two types of generalized Baxter-Wu models, by means of transfer-matrix and Monte Carlo techniques. The first generalization allows for different couplings in the up- and down-triangles, and the second generalization is to a q-state spin model with three-spin interactions. Both

  3. Charge uncovering effects on flute instabilities in hot electron plasmas

    International Nuclear Information System (INIS)

    Spong, D.A.

    1985-01-01

    Recent measurements and concurrent theoretical equilibrium models of the ELMO Bumpy Torus (EBT) edge plasma region [as described by E. F. Jaeger et al. in Magnetic Well Depth in EBT and Sensitivity to Hot Electron Ring Geometry, ORNL/TM-9185 (1984)] have indicated that the hot electron ring beta β/sub hot/ at the C-T transition may not always be sufficient to produce the local minimum in the magnetic field thought to be necessary for MHD stability. This has led to the examination of other mechanisms that could account for the observed stability of the T-mode. In this report, an effect known as charge uncovering, which depends not on the value of β/sub hot/ but rather on the ratio n/sub hot//n/sub core/, is studied

  4. Uncovering an Existential Barrier to Breast Self-exam Behavior.

    Science.gov (United States)

    Goldenberg, Jamie L; Arndt, Jamie; Hart, Joshua; Routledge, Clay

    2008-03-01

    The present research applies an analysis derived from terror management theory to the health domain of breast examination, and in doing so uncovers previously unrecognized factors that may contribute to women's reluctance to perform breast self-examinations (BSEs). In Study 1, when concerns about mortality were primed, reminders of human beings' physical nature (i.e., creatureliness) reduced intentions to conduct BSEs compared to reminders of humans' uniqueness. In Study 2, women conducted shorter exams on a breast model (an experience found to increase death-thought accessibility) when creatureliness was primed compared to a uniqueness and no essay condition. In Study 3, after a creatureliness prime, women performed shorter BSEs when a placebo did not provide an alternative explanation for their discomfort compared to when it did. Advances for theory and breast self-exam promotion are discussed.

  5. Dynamic behavior of the HTR-10 reactor: Dual temperature feedback model

    Directory of Open Access Journals (Sweden)

    Hosseini Seyed Ali

    2015-01-01

    Full Text Available The current work aims at presenting a simple model for PBM-type reactors' dynamic behavior analysis. The proposed model is based on point kinetics equations coupled with feedbacks from fuel and moderator temperatures. The temperature reactivity coefficients were obtained through MCNP code and via available experimental data. Parameters such as heat capacity and heat conductivity were carefully analyzed and the final system of equations was numerically solved. The obtained results, while in partial agreement with previously proposed models, suggest lower sensitivity to step reactivity insertion as compared to other reactor designs and inherent safety of the design.

  6. A Dual-Route Model that Learns to Pronounce English Words

    Science.gov (United States)

    Remington, Roger W.; Miller, Craig S.; Null, Cynthia H. (Technical Monitor)

    1995-01-01

    This paper describes a model that learns to pronounce English words. Learning occurs in two modules: 1) a rule-based module that constructs pronunciations by phonetic analysis of the letter string, and 2) a whole-word module that learns to associate subsets of letters to the pronunciation, without phonetic analysis. In a simulation on a corpus of over 300 words the model produced pronunciation latencies consistent with the effects of word frequency and orthographic regularity observed in human data. Implications of the model for theories of visual word processing and reading instruction are discussed.

  7. Automatic left-atrial segmentation from cardiac 3D ultrasound: a dual-chamber model-based approach

    Science.gov (United States)

    Almeida, Nuno; Sarvari, Sebastian I.; Orderud, Fredrik; Gérard, Olivier; D'hooge, Jan; Samset, Eigil

    2016-04-01

    In this paper, we present an automatic solution for segmentation and quantification of the left atrium (LA) from 3D cardiac ultrasound. A model-based framework is applied, making use of (deformable) active surfaces to model the endocardial surfaces of cardiac chambers, allowing incorporation of a priori anatomical information in a simple fashion. A dual-chamber model (LA and left ventricle) is used to detect and track the atrio-ventricular (AV) plane, without any user input. Both chambers are represented by parametric surfaces and a Kalman filter is used to fit the model to the position of the endocardial walls detected in the image, providing accurate detection and tracking during the whole cardiac cycle. This framework was tested in 20 transthoracic cardiac ultrasound volumetric recordings of healthy volunteers, and evaluated using manual traces of a clinical expert as a reference. The 3D meshes obtained with the automatic method were close to the reference contours at all cardiac phases (mean distance of 0.03+/-0.6 mm). The AV plane was detected with an accuracy of -0.6+/-1.0 mm. The LA volumes assessed automatically were also in agreement with the reference (mean +/-1.96 SD): 0.4+/-5.3 ml, 2.1+/-12.6 ml, and 1.5+/-7.8 ml at end-diastolic, end-systolic and pre-atrial-contraction frames, respectively. This study shows that the proposed method can be used for automatic volumetric assessment of the LA, considerably reducing the analysis time and effort when compared to manual analysis.

  8. P2-16: Dual-Bound Model and the Role of Time Bound in Perceptual Decision Making

    Directory of Open Access Journals (Sweden)

    Daeseob Lim

    2012-10-01

    Full Text Available The diffusion model (DM encapsulates the dynamics of perceptual decision within a ‘diffusion field’ that is defined by a basis with sensory-evidence (SE and time vectors. At the core of the DM, it assumes that a decision is not made until an evidence particle drifts in the diffusion field and eventually hits one of the two pre-fixed bounds defined in the SE axis. This assumption dictates when and which choice is made by referring to when and which bound will be hit by the evidence particle. What if urgency pressures the decision system to make a choice even when the evidence particle has yet hit the SE bound? Previous modeling attempts at coping with time pressure, despite differences in detail, all manipulated the coordinate of SE bounds. Here, we offer a novel solution by adopting another bound on the time axis. This ‘dual-bound’ model (DBM posits that decisions can also be made when the evidence particle hits a time bound, which is determined on a trial-by-trial basis by a ‘perceived time interval’ – how long the system can stay in the ‘diffusion’ field. The classic single-bound model (SBM exhibited systematic errors in predicting both the reaction time distributions and the time-varying bias in choice. Those errors were not corrected by previously proposed variants of the SBM until the time bound was introduced. The validity of the DBM was further supported by the strong across-individual correlation between observed precision of interval timing and the predicted trial-by-trial variability of the time bound.

  9. Numerical modeling and sensitivity analysis of seawater intrusion in a dual-permeability coastal karst aquifer with conduit networks

    Science.gov (United States)

    Xu, Zexuan; Hu, Bill X.; Ye, Ming

    2018-01-01

    Long-distance seawater intrusion has been widely observed through the subsurface conduit system in coastal karst aquifers as a source of groundwater contaminant. In this study, seawater intrusion in a dual-permeability karst aquifer with conduit networks is studied by the two-dimensional density-dependent flow and transport SEAWAT model. Local and global sensitivity analyses are used to evaluate the impacts of boundary conditions and hydrological characteristics on modeling seawater intrusion in a karst aquifer, including hydraulic conductivity, effective porosity, specific storage, and dispersivity of the conduit network and of the porous medium. The local sensitivity analysis evaluates the parameters' sensitivities for modeling seawater intrusion, specifically in the Woodville Karst Plain (WKP). A more comprehensive interpretation of parameter sensitivities, including the nonlinear relationship between simulations and parameters, and/or parameter interactions, is addressed in the global sensitivity analysis. The conduit parameters and boundary conditions are important to the simulations in the porous medium because of the dynamical exchanges between the two systems. The sensitivity study indicates that salinity and head simulations in the karst features, such as the conduit system and submarine springs, are critical for understanding seawater intrusion in a coastal karst aquifer. The evaluation of hydraulic conductivity sensitivity in the continuum SEAWAT model may be biased since the conduit flow velocity is not accurately calculated by Darcy's equation as a function of head difference and hydraulic conductivity. In addition, dispersivity is no longer an important parameter in an advection-dominated karst aquifer with a conduit system, compared to the sensitivity results in a porous medium aquifer. In the end, the extents of seawater intrusion are quantitatively evaluated and measured under different scenarios with the variabilities of important parameters

  10. Numerical modeling and sensitivity analysis of seawater intrusion in a dual-permeability coastal karst aquifer with conduit networks

    Directory of Open Access Journals (Sweden)

    Z. Xu

    2018-01-01

    Full Text Available Long-distance seawater intrusion has been widely observed through the subsurface conduit system in coastal karst aquifers as a source of groundwater contaminant. In this study, seawater intrusion in a dual-permeability karst aquifer with conduit networks is studied by the two-dimensional density-dependent flow and transport SEAWAT model. Local and global sensitivity analyses are used to evaluate the impacts of boundary conditions and hydrological characteristics on modeling seawater intrusion in a karst aquifer, including hydraulic conductivity, effective porosity, specific storage, and dispersivity of the conduit network and of the porous medium. The local sensitivity analysis evaluates the parameters' sensitivities for modeling seawater intrusion, specifically in the Woodville Karst Plain (WKP. A more comprehensive interpretation of parameter sensitivities, including the nonlinear relationship between simulations and parameters, and/or parameter interactions, is addressed in the global sensitivity analysis. The conduit parameters and boundary conditions are important to the simulations in the porous medium because of the dynamical exchanges between the two systems. The sensitivity study indicates that salinity and head simulations in the karst features, such as the conduit system and submarine springs, are critical for understanding seawater intrusion in a coastal karst aquifer. The evaluation of hydraulic conductivity sensitivity in the continuum SEAWAT model may be biased since the conduit flow velocity is not accurately calculated by Darcy's equation as a function of head difference and hydraulic conductivity. In addition, dispersivity is no longer an important parameter in an advection-dominated karst aquifer with a conduit system, compared to the sensitivity results in a porous medium aquifer. In the end, the extents of seawater intrusion are quantitatively evaluated and measured under different scenarios with the variabilities of

  11. Dual Value Creation and Business Model Design: An Ethnographic Study of an Internationalizing NGO

    DEFF Research Database (Denmark)

    Turcan, Romeo V.

    This ethnographic research explores the process of business model design in the context of an NGO internationalizing to an emerging market. It contributes to the business model literature by investigating how this NGO - targeting multiple key stakeholders - was experimenting (1) with value...... proposition; (2) creating the value/promise; and (3) delivering the value. Theoretically the paper is grounded in the dynamic capability view of the firm providing venues for future research and implications for policy and practice....

  12. Seeing the Wood for the Trees: Applying the dual-memory system model to investigate expert teachers' observational skills in natural ecological learning environments

    Science.gov (United States)

    Stolpe, Karin; Björklund, Lars

    2012-01-01

    This study aims to investigate two expert ecology teachers' ability to attend to essential details in a complex environment during a field excursion, as well as how they teach this ability to their students. In applying a cognitive dual-memory system model for learning, we also suggest a rationale for their behaviour. The model implies two separate memory systems: the implicit, non-conscious, non-declarative system and the explicit, conscious, declarative system. This model provided the starting point for the research design. However, it was revised from the empirical findings supported by new theoretical insights. The teachers were video and audio recorded during their excursion and interviewed in a stimulated recall setting afterwards. The data were qualitatively analysed using the dual-memory system model. The results show that the teachers used holistic pattern recognition in their own identification of natural objects. However, teachers' main strategy to teach this ability is to give the students explicit rules or specific characteristics. According to the dual-memory system model the holistic pattern recognition is processed in the implicit memory system as a non-conscious match with earlier experienced situations. We suggest that this implicit pattern matching serves as an explanation for teachers' ecological and teaching observational skills. Another function of the implicit memory system is its ability to control automatic behaviour and non-conscious decision-making. The teachers offer the students firsthand sensory experiences which provide a prerequisite for the formation of implicit memories that provides a foundation for expertise.

  13. Numerical Model of a Variable-Combined-Cycle Engine for Dual Subsonic and Supersonic Cruise

    Directory of Open Access Journals (Sweden)

    Victor Fernandez-Villace

    2013-02-01

    Full Text Available Efficient high speed propulsion requires exploiting the cooling capability of the cryogenic fuel in the propulsion cycle. This paper presents the numerical model of a combined cycle engine while in air turbo-rocket configuration. Specific models of the various heat exchanger modules and the turbomachinery elements were developed to represent the physical behavior at off-design operation. The dynamic nature of the model allows the introduction of the engine control logic that limits the operation of certain subcomponents and extends the overall engine operational envelope. The specific impulse and uninstalled thrust are detailed while flying a determined trajectory between Mach 2.5 and 5 for varying throttling levels throughout the operational envelope.

  14. Dual purpose use of preterm piglets as a model of pediatric GI disease

    DEFF Research Database (Denmark)

    Oosterloo, Berthe C; Premkumar, Muralidhar; Stoll, Barbara

    2014-01-01

    Necrotizing enterocolitis (NEC) is the most common gastrointestinal complication in human neonates, yet the pathogenesis of this disease remains poorly understood. A fundamental approach to understanding the etiology and underlying biology of NEC is the use of in vivo experimental animal models...... of mice is the abilty to test how genetic disruption of specific genes alters the NEC phenotype. More recently, pigs have emerged as an animal model of NEC and used to establish the role of bacterial colonization, prematurity, parenteral nutrition and antibiotic therapy. This review will outline some...

  15. On the Asymptotic Capacity of Dual-Aperture FSO Systems with a Generalized Pointing Error Model

    KAUST Repository

    Al-Quwaiee, Hessa

    2016-06-28

    Free-space optical (FSO) communication systems are negatively affected by two physical phenomenon, namely, scintillation due to atmospheric turbulence and pointing errors. To quantify the effect of these two factors on FSO system performance, we need an effective mathematical model for them. In this paper, we propose and study a generalized pointing error model based on the Beckmann distribution. We then derive a generic expression of the asymptotic capacity of FSO systems under the joint impact of turbulence and generalized pointing error impairments. Finally, the asymptotic channel capacity formula are extended to quantify the FSO systems performance with selection and switched-and-stay diversity.

  16. Sustained response with ixekizumab treatment of moderate-to-severe psoriasis with scalp involvement: results from three phase 3 trials (UNCOVER-1, UNCOVER-2, UNCOVER-3).

    Science.gov (United States)

    Reich, Kristian; Leonardi, Craig; Lebwohl, Mark; Kerdel, Francisco; Okubo, Yukari; Romiti, Ricardo; Goldblum, Orin; Dennehy, Ellen B; Kerr, Lisa; Sofen, Howard

    2017-06-01

    Scalp is a frequently affected and difficult-to-treat area in psoriasis patients. We assessed the efficacy of ixekizumab in the treatment of patients with scalp psoriasis over 60 weeks using the Psoriasis Scalp Severity Index (PSSI). In three Phase 3, multicenter, double-blind, placebo-controlled trials, patients with moderate-to-severe psoriasis in UNCOVER-1 (N = 1296), UNCOVER-2 (N = 1224) and UNCOVER-3 (N = 1346) were randomized to subcutaneous 80 mg ixekizumab every two weeks (Q2W) or every four weeks (Q4W) after a 160 mg starting dose, or placebo through Week 12. Additional UNCOVER-2 and UNCOVER-3 cohorts were randomized to 50 mg bi-weekly etanercept through Week 12. Patients entering the open-label long-term extension (LTE) (UNCOVER-3) received ixekizumab Q4W; UNCOVER-1 and UNCOVER-2 included a blinded maintenance period in which static physician global assessment (sPGA) 0/1 responders were re-randomized to placebo, ixekizumab Q4W, or 80 mg ixekizumab every 12 weeks (Q12W) through Week 60. In patients with moderate-to-severe psoriasis with baseline scalp involvement, PSSI 90 and 100 were achieved at Week 12 in higher percentages of patients treated with ixekizumab Q2W (81.7% and 74.6%) or ixekizumab Q4W (75.6% and 68.9%) compared with patients treated with placebo (7.6% and 6.7%; p psoriasis in patients with moderate-to-severe psoriasis, with most patients achieving complete or near-complete resolution of scalp psoriasis and maintaining this response over 60 weeks.

  17. Dual Entwining Structures and Dual Entwined Modules

    OpenAIRE

    Abuhlail, Jawad Y.

    2003-01-01

    In this note we introduce and investigate the concepts of dual entwining structures and dual entwined modules. This generalizes the concepts of dual Doi-Koppinen structures and dual Doi-Koppinen modules introduced (in the infinite case over rings) by the author is his dissertation.

  18. Theoretical modelling of dual-wavelength pumped Yb3+–Tm3+ co-doped silica fibre laser

    International Nuclear Information System (INIS)

    Fu, Yuqing; Chen, Jianguo

    2010-01-01

    Numerical simulations have, for the first time to our knowledge, been carried out to characterize the Yb 3+ –Tm 3+ co-doped silica fibre laser (YTFL), defined by a fibre grating and an end mirror, by using the rate equations, which take into consideration both the energy transfer processes from Yb 3+ to Tm 3+ ions and the cross-relaxation processes among different Tm 3+ ions. A dual-wavelength pumping scheme with one at 805 nm and the other at 975 nm is used to pump the YTFL. We have investigated the wavelength-dependent output power of the YTFL, from 1750 to 2200 nm, which takes its maximum output power at ∼ 1800 nm. The effect of the cross-relaxation processes in the Tm 3+ -doped silica fibre laser has been studied. The results indicate that these processes are beneficial to the laser and should be considered in the theoretical modelling. The influence of the Yb 3+ concentration on the characteristics of the YTFL has also been analysed and the results show that Yb 3+ dopants can improve the output power and slope efficiency of the laser

  19. Modeling and analysis of dual-output piezoelectric transformer operating at the thickness-shear vibration mode.

    Science.gov (United States)

    Du, Jinlong; Hu, Junhui; Tseng, King-Jet; Kai, Chen Shu; Siong, Goh Chee

    2006-03-01

    In our previous study, the multioutput piezoelectric transformer operating at the thickness-shear vibration mode was proposed and experimentally investigated. By designing a new construction of support and lead wire connection, a power density of 52.7 W/cm3 and a total output power of 169.8 W were achieved at a temperature rise less than 20 degrees C. In this work, a theoretical model was developed for the dual-output piezoelectric transformer operating at the thickness-shear vibration mode. The equivalent circuit parameters of the piezoelectric transformer were derived. Based on this, the impedance characteristics, equivalent inductance, capacitance ratio, voltage gain, and efficiency of the piezoelectric transformer were calculated. The theoretical results were verified by experimental data. Furthermore, the effect of the transformer size on the voltage gain, efficiency, output power and power density, and the effect of the load of one output on the voltage gain of another output were analyzed. Some useful guidelines were achieved by these analyses.

  20. Modeling the shape and composition of the human body using dual energy X-ray absorptiometry images.

    Science.gov (United States)

    Shepherd, John A; Ng, Bennett K; Fan, Bo; Schwartz, Ann V; Cawthon, Peggy; Cummings, Steven R; Kritchevsky, Stephen; Nevitt, Michael; Santanasto, Adam; Cootes, Timothy F

    2017-01-01

    There is growing evidence that body shape and regional body composition are strong indicators of metabolic health. The purpose of this study was to develop statistical models that accurately describe holistic body shape, thickness, and leanness. We hypothesized that there are unique body shape features that are predictive of mortality beyond standard clinical measures. We developed algorithms to process whole-body dual-energy X-ray absorptiometry (DXA) scans into body thickness and leanness images. We performed statistical appearance modeling (SAM) and principal component analysis (PCA) to efficiently encode the variance of body shape, leanness, and thickness across sample of 400 older Americans from the Health ABC study. The sample included 200 cases and 200 controls based on 6-year mortality status, matched on sex, race and BMI. The final model contained 52 points outlining the torso, upper arms, thighs, and bony landmarks. Correlation analyses were performed on the PCA parameters to identify body shape features that vary across groups and with metabolic risk. Stepwise logistic regression was performed to identify sex and race, and predict mortality risk as a function of body shape parameters. These parameters are novel body composition features that uniquely identify body phenotypes of different groups and predict mortality risk. Three parameters from a SAM of body leanness and thickness accurately identified sex (training AUC = 0.99) and six accurately identified race (training AUC = 0.91) in the sample dataset. Three parameters from a SAM of only body thickness predicted mortality (training AUC = 0.66, validation AUC = 0.62). Further study is warranted to identify specific shape/composition features that predict other health outcomes.

  1. 3D Hatching : Linear halftoning for dual extrusion fused deposition modeling

    NARCIS (Netherlands)

    Kuipers, Tim; Doubrovski, E.L.; Verlinden, J.C.

    2017-01-01

    This work presents halftoning techniques to manufacture 3D objects with the appearance of full grayscale imagery for Fused Deposition Modeling (FDM) printers. While droplet-based dithering is a common halftoning technique, this is not applicable to FDM printing, since FDM builds up objects by

  2. Interaction between π mesons and nucleons in a realistic dual model

    International Nuclear Information System (INIS)

    Antonov, E.N.; Kudryavtsev, V.A.

    1985-01-01

    The narrow-resonance model with quantized slope of the Regge trajectories proposed earlier by one of the authors is used to describe the interaction between π mesons and nucleons. The value of the coupling g 2 /sub piN/Nroughly-equal12 is found in the Born approximation

  3. Rational misbehavior? Evaluating an integrated dual-process model of criminal decision making

    NARCIS (Netherlands)

    van Gelder, J.L.; de Vries, R.E.

    2014-01-01

    Objectives: Test the hypothesis that dispositional self-control and morality relate to criminal decision making via different mental processing modes, a 'hot' affective mode and a 'cool' cognitive one. Methods: Structural equation modeling in two studies under separate samples of undergraduate

  4. Dual Role of Host Par2 in a Murine Model of Spontaneous Metastatic B16 Melanoma

    Czech Academy of Sciences Publication Activity Database

    Olejár, Tomáš; Větvička, D.; Zadinová, M.; Poučková, P.; Kukal, J.; Ježek, Petr; Matěj, R.

    2014-01-01

    Roč. 34, č. 7 (2014), s. 3511-3515 ISSN 0250-7005 R&D Projects: GA ČR(CZ) GAP302/10/0346 Institutional support: RVO:67985823 Keywords : PAR2 * melanoma * metastasis * murine model Subject RIV: EA - Cell Biology Impact factor: 1.826, year: 2014

  5. Judgment and Decision Making in Outdoor Adventure Leadership: A Dual-Process Model

    Science.gov (United States)

    Culp, Clinton A.

    2016-01-01

    From an examination of the current textbooks and literature concerning judgment and decision-making models used in outdoor adventure leadership, it is easy to see that they are still deeply rooted in the classical decision-making theory. In this article, I will (a) outline the importance of good judgment and decision making in an outdoor adventure…

  6. A Dual-Process Discrete-Time Survival Analysis Model: Application to the Gateway Drug Hypothesis

    Science.gov (United States)

    Malone, Patrick S.; Lamis, Dorian A.; Masyn, Katherine E.; Northrup, Thomas F.

    2010-01-01

    The gateway drug model is a popular conceptualization of a progression most substance users are hypothesized to follow as they try different legal and illegal drugs. Most forms of the gateway hypothesis are that "softer" drugs lead to "harder," illicit drugs. However, the gateway hypothesis has been notably difficult to…

  7. Uncovering Indicators of Commercial Sexual Exploitation.

    Science.gov (United States)

    Bounds, Dawn; Delaney, Kathleen R; Julion, Wrenetha; Breitenstein, Susan

    2017-07-01

    It is estimated that annually 100,000 to 300,000 youth are at risk for sex trafficking; a commercial sex act induced by force, fraud, or coercion, or any such act where the person induced to perform such an act is younger than 18 years of age. Increasingly, such transactions are occurring online via Internet-based sites that serve the commercial sex industry. Commercial sex transactions involving trafficking are illegal; thus, Internet discussions between those involved must be veiled. Even so, transactions around sex trafficking do occur. Within these transactions are innuendos that provide one avenue for detecting potential activity. The purpose of this study is to identify linguistic indicators of potential commercial sexual exploitation within the online comments of men posted on an Internet site. Six hundred sixty-six posts from five Midwest cities and 363 unique members were analyzed via content analysis. Three main indicators were found: the presence of youth or desire for youthfulness, presence of pimps, and awareness of vulnerability. These findings begin a much-needed dialogue on uncovering online risks of commercial sexual exploitation and support the need for further research on Internet indicators of sex trafficking.

  8. Uncovering missing links with cold ends

    Science.gov (United States)

    Zhu, Yu-Xiao; Lü, Linyuan; Zhang, Qian-Ming; Zhou, Tao

    2012-11-01

    To evaluate the performance of prediction of missing links, the known data are randomly divided into two parts, the training set and the probe set. We argue that this straightforward and standard method may lead to terrible bias, since in real biological and information networks, missing links are more likely to be links connecting low-degree nodes. We therefore study how to uncover missing links with low-degree nodes, namely links in the probe set are of lower degree products than a random sampling. Experimental analysis on ten local similarity indices and four disparate real networks reveals a surprising result that the Leicht-Holme-Newman index [E.A. Leicht, P. Holme, M.E.J. Newman, Vertex similarity in networks, Phys. Rev. E 73 (2006) 026120] performs the best, although it was known to be one of the worst indices if the probe set is a random sampling of all links. We further propose an parameter-dependent index, which considerably improves the prediction accuracy. Finally, we show the relevance of the proposed index to three real sampling methods: acquaintance sampling, random-walk sampling and path-based sampling.

  9. A New Analytical Subthreshold Behavior Model for Single-Halo, Dual-Material Gate Silicon-on-Insulator Metal Oxide Semiconductor Field Effect Transistor

    Science.gov (United States)

    Chiang, Te-Kuang

    2008-11-01

    On the basis of the exact solution of the two-dimensional Poisson equation, a new analytical subthreshold behavior model consisting of the two-dimensional potential, threshold voltage, and subthreshold current for the single-halo, dual-material gate (SHDMG) silicon-on-insulator (SOI) metal oxide semiconductor field effect transistor (MOSFET) is developed. The model is verified by the good agreement with a numerical simulation using the device simulator MEDICI. The model not only offers a physical insight into device physics but is also an efficient device model for the circuit simulation.

  10. Covered versus uncovered metal stents for malignant gastric outlet obstruction: Systematic review and meta-analysis.

    Science.gov (United States)

    Hamada, Tsuyoshi; Hakuta, Ryunosuke; Takahara, Naminatsu; Sasaki, Takashi; Nakai, Yousuke; Isayama, Hiroyuki; Koike, Kazuhiko

    2017-05-01

    Self-expandable metal stents (SEMS) are used for non-resectable malignant gastric outlet obstruction (GOO). Studies of covered versus uncovered SEMS have yielded inconsistent results as a result of heterogeneity in design and patient population. We carried out a meta-analysis to compare covered and uncovered gastroduodenal SEMS. Using MEDLINE, Embase, and the Cochrane database, we identified 1624 patients from 13 prospective and retrospective studies that evaluated covered and uncovered SEMS for malignant GOO and were published until October 2016. We pooled data on SEMS dysfunction, technical and clinical success, and adverse events using the fixed-effect or random-effects model. Compared with uncovered SEMS, covered SEMS did not show any significant difference in stent dysfunction risk (risk ratio [RR], 1.02; 95% confidence interval [CI], 0.79-1.32). A subgroup analysis of five randomized trials suggested a trend toward a lower dysfunction risk in covered SEMS (RR, 0.63; 95% CI, 0.45-0.88). Covered SEMS were associated with a lower occlusion risk (RR, 0.44; 95% CI, 0.28-0.68), but with a higher migration risk (RR, 4.28; 95% CI, 2.89-6.34). Technical and clinical success rates were comparable between the groups. Overall adverse events tended to be more frequent in covered SEMS (RR, 1.75; 95% CI, 1.09-2.83). Outcomes of covered and uncovered gastroduodenal SEMS were comparable, although the lower dysfunction rate of covered SEMS observed in the analysis of randomized trials needs further investigation. Antimigration mechanisms for covered SEMS and identification of patients who can achieve longer patency from uncovered SEMS would help improve the outcomes of gastroduodenal SEMS. © 2016 Japan Gastroenterological Endoscopy Society.

  11. Uncovering cortical MEG responses to listened audiobook stories.

    Science.gov (United States)

    Koskinen, M; Seppä, M

    2014-10-15

    Naturalistic stimuli, such as normal speech and narratives, are opening up intriguing prospects in neuroscience, especially when merging neuroimaging with machine learning methodology. Here we propose a task-optimized spatial filtering strategy for uncovering individual magnetoencephalographic (MEG) responses to audiobook stories. Ten subjects listened to 1-h-long recording once, as well as to 48 repetitions of a 1-min-long speech passage. Employing response replicability as statistical validity and utilizing unsupervised learning methods, we trained spatial filters that were able to generalize over datasets of an individual. For this blind-signal-separation (BSS) task, we derived a version of multi-set similarity-constrained canonical correlation analysis (SimCCA) that theoretically provides maximal signal-to-noise ratio (SNR) in this setting. Irrespective of significant noise in unaveraged MEG traces, the method successfully uncovered feasible time courses up to ~120 Hz, with the most prominent signals below 20 Hz. Individual trial-to-trial correlations of such time courses reached the level of 0.55 (median 0.33 in the group) at ~0.5 Hz, with considerable variation between subjects. By this filtering, the SNR increased up to 20 times. In comparison, independent component analysis (ICA) or principal component analysis (PCA) did not improve SNR notably. The validity of the extracted brain signals was further assessed by inspecting their associations with the stimulus, as well as by mapping the contributing cortical signal sources. The results indicate that the proposed methodology effectively reduces noise in MEG recordings to that extent that brain responses can be seen to nonrecurring audiobook stories. The study paves the way for applications aiming at accurately modeling the stimulus-response-relationship by tackling the response variability, as well as for real-time monitoring of brain signals of individuals in naturalistic experimental conditions. Copyright

  12. Static Object Detection Based on a Dual Background Model and a Finite-State Machine

    Directory of Open Access Journals (Sweden)

    Heras Evangelio Rubén

    2011-01-01

    Full Text Available Detecting static objects in video sequences has a high relevance in many surveillance applications, such as the detection of abandoned objects in public areas. In this paper, we present a system for the detection of static objects in crowded scenes. Based on the detection of two background models learning at different rates, pixels are classified with the help of a finite-state machine. The background is modelled by two mixtures of Gaussians with identical parameters except for the learning rate. The state machine provides the meaning for the interpretation of the results obtained from background subtraction; it can be implemented as a look-up table with negligible computational cost and it can be easily extended. Due to the definition of the states in the state machine, the system can be used either full automatically or interactively, making it extremely suitable for real-life surveillance applications. The system was successfully validated with several public datasets.

  13. Mean field theories and dual variation mathematical structures of the mesoscopic model

    CERN Document Server

    Suzuki, Takashi

    2015-01-01

    Mean field approximation has been adopted to describe macroscopic phenomena from microscopic overviews. It is still in progress; fluid mechanics, gauge theory, plasma physics, quantum chemistry, mathematical oncology, non-equilibirum thermodynamics.  spite of such a wide range of scientific areas that are concerned with the mean field theory, a unified study of its mathematical structure has not been discussed explicitly in the open literature.  The benefit of this point of view on nonlinear problems should have significant impact on future research, as will be seen from the underlying features of self-assembly or bottom-up self-organization which is to be illustrated in a unified way. The aim of this book is to formulate the variational and hierarchical aspects of the equations that arise in the mean field theory from macroscopic profiles to microscopic principles, from dynamics to equilibrium, and from biological models to models that arise from chemistry and physics.

  14. 3D Hatching: Linear halftoning for dual extrusion fused deposition modeling

    OpenAIRE

    Kuipers, Tim; Doubrovski, E.L.; Verlinden, J.C.

    2017-01-01

    This work presents halftoning techniques to manufacture 3D objects with the appearance of full grayscale imagery for Fused Deposition Modeling (FDM) printers. While droplet-based dithering is a common halftoning technique, this is not applicable to FDM printing, since FDM builds up objects by extruding material in semi-continuous paths. A set of three methods is presented which apply a linear halftoning principle called 'hatching' to horizontal, vertical and diagonal surfaces. These methods a...

  15. Enhancing hit identification in Mycobacterium tuberculosis drug discovery using validated dual-event Bayesian models.

    Directory of Open Access Journals (Sweden)

    Sean Ekins

    Full Text Available High-throughput screening (HTS in whole cells is widely pursued to find compounds active against Mycobacterium tuberculosis (Mtb for further development towards new tuberculosis (TB drugs. Hit rates from these screens, usually conducted at 10 to 25 µM concentrations, typically range from less than 1% to the low single digits. New approaches to increase the efficiency of hit identification are urgently needed to learn from past screening data. The pharmaceutical industry has for many years taken advantage of computational approaches to optimize compound libraries for in vitro testing, a practice not fully embraced by academic laboratories in the search for new TB drugs. Adapting these proven approaches, we have recently built and validated Bayesian machine learning models for predicting compounds with activity against Mtb based on publicly available large-scale HTS data from the Tuberculosis Antimicrobial Acquisition Coordinating Facility. We now demonstrate the largest prospective validation to date in which we computationally screened 82,403 molecules with these Bayesian models, assayed a total of 550 molecules in vitro, and identified 124 actives against Mtb. Individual hit rates for the different datasets varied from 15-28%. We have identified several FDA approved and late stage clinical candidate kinase inhibitors with activity against Mtb which may represent starting points for further optimization. The computational models developed herein and the commercially available molecules derived from them are now available to any group pursuing Mtb drug discovery.

  16. How the dual process model of human cognition can inform efforts to de-implement ineffective and harmful clinical practices: A preliminary model of unlearning and substitution.

    Science.gov (United States)

    Helfrich, Christian D; Rose, Adam J; Hartmann, Christine W; van Bodegom-Vos, Leti; Graham, Ian D; Wood, Suzanne J; Majerczyk, Barbara R; Good, Chester B; Pogach, Leonard M; Ball, Sherry L; Au, David H; Aron, David C

    2018-02-01

    One way to understand medical overuse at the clinician level is in terms of clinical decision-making processes that are normally adaptive but become maladaptive. In psychology, dual process models of cognition propose 2 decision-making processes. Reflective cognition is a conscious process of evaluating options based on some combination of utility, risk, capabilities, and/or social influences. Automatic cognition is a largely unconscious process occurring in response to environmental or emotive cues based on previously learned, ingrained heuristics. De-implementation strategies directed at clinicians may be conceptualized as corresponding to cognition: (1) a process of unlearning based on reflective cognition and (2) a process of substitution based on automatic cognition. We define unlearning as a process in which clinicians consciously change their knowledge, beliefs, and intentions about an ineffective practice and alter their behaviour accordingly. Unlearning has been described as "the questioning of established knowledge, habits, beliefs and assumptions as a prerequisite to identifying inappropriate or obsolete knowledge underpinning and/or embedded in existing practices and routines." We hypothesize that as an unintended consequence of unlearning strategies clinicians may experience "reactance," ie, feel their professional prerogative is being violated and, consequently, increase their commitment to the ineffective practice. We define substitution as replacing the ineffective practice with one or more alternatives. A substitute is a specific alternative action or decision that either precludes the ineffective practice or makes it less likely to occur. Both approaches may work independently, eg, a substitute could displace an ineffective practice without changing clinicians' knowledge, and unlearning could occur even if no alternative exists. For some clinical practice, unlearning and substitution strategies may be most effectively used together. By taking into

  17. Two-dimensional model for subthreshold current and subthreshold swing of graded-channel dual-material double-gate (GCDMDG) MOSFETs

    Science.gov (United States)

    Goel, Ekta; Kumar, Sanjay; Singh, Balraj; Singh, Kunal; Jit, Satyabrata

    2017-06-01

    The subthreshold performance of graded-channel dual-material double-gate (GCDMDG) MOSFETs is examined through two-dimensional (2D) analytical modeling of subthreshold-current (SC) and subthreshold-swing (SS). The potential function obtained by using the parabolic approach to solve the 2D Poisson's equation, has been used to formulate SC and SS characteristics of the device. The variations of SS against different device parameters have been obtained with the help of effective conduction path parameter. The SC and SS characteristics of the GCDMDG MOS transistor have been compared with those of the dual-material double-gate (DMDG) and simple graded-channel double-gate (GCDG) MOS structures to show its better subthreshold characteristics over the latter two devices. The results of the developed model are well-agreed with the commercially available SILVACO ATLAS™ simulator data.

  18. Research to Develop Process Models for Producing a Dual Property Titanium Alloy Compressor Disk.

    Science.gov (United States)

    1981-10-01

    34SI.- .1. $ CL) 1.3.2 (SF) POC E -ADE!.E I, I, (CO.) 1.1.6 ( WSU ( TEL) VALIDATE 1.3.3 1.3.4 (COR) MATERIAL MODELING PROCESS MODEING INTERFACE "CUELING...pp. 49-62. (5) Patton , N. E. and Mahoney, M. W., "Creep of Titanium-Silicon Alloys", Met. Trans. A., 1976, Vol. 7A, pp. 1685-1694. 15 In conclusion...expressions, the WSU equations are very manageable and replicate the measured flow stress data to a high degree of precision. (6)Hart, E. W., "A

  19. Evaluating the unequal-variance and dual-process explanations of zROC slopes with response time data and the diffusion model

    OpenAIRE

    Starns, Jeffrey J.; Ratcliff, Roger; McKoon, Gail

    2011-01-01

    We tested two explanations for why the slope of the z-transformed receiver operating characteristic (zROC) is less than 1 in recognition memory: the unequal-variance account (target evidence is more variable than lure evidence) or the dual-process account (responding reflects both a continuous familiarity process and a threshold recollection process). These accounts are typically implemented in signal detection models that do not make predictions for response time (RT) data. We tested them us...

  20. Conducting to non-conducting transition in dual transmission lines using a ternary model with long-range correlated disorder

    International Nuclear Information System (INIS)

    Lazo, E.; Diez, E.

    2010-01-01

    In this work we study the behavior of the allowed and forbidden frequencies in disordered classical dual transmission lines when the values of capacitances {C j } are distributed according to a ternary model with long-range correlated disorder. We introduce the disorder from a random sequence with a power spectrum S(k)∝k -(2α-1) , where α≥0.5 is the correlation exponent. From this sequence we generate an asymmetric ternary map using two map parameters b 1 and b 2 , which adjust the occupancy probability of each possible value of the capacitances C j ={C A, C B, C C, }. If the sequence of capacitance values is totally at random α=0.5 (white noise), the electrical transmission line is in the non-conducting state for every frequency ω. When we introduce long-range correlations in the distribution of capacitances, the electrical transmission lines can change their conducting properties and we can find a transition from the non-conducting to conducting state for a fixed system size. This implies the existence of critical values of the map parameters for each correlation exponent α. By performing finite-size scaling we obtain the asymptotic value of the map parameters in the thermodynamic limit for any α. With these data we obtain a phase diagram for the symmetric ternary model, which separates the non-conducting state from the conducting one. This is the fundamental result of this Letter. In addition, introducing one or more impurities in random places of the long-range correlated distribution of capacitances, we observe a dramatic change in the conducting properties of the electrical transmission lines, in such a way that the system jumps from conducting to non-conducting states. We think that this behavior can be considered as a possible mechanism to secure communication.

  1. Nitrate source apportionment using a combined dual isotope, chemical and bacterial property, and Bayesian model approach in river systems

    Science.gov (United States)

    Xia, Yongqiu; Li, Yuefei; Zhang, Xinyu; Yan, Xiaoyuan

    2017-01-01

    Nitrate (NO3-) pollution is a serious problem worldwide, particularly in countries with intensive agricultural and population activities. Previous studies have used δ15N-NO3- and δ18O-NO3- to determine the NO3- sources in rivers. However, this approach is subject to substantial uncertainties and limitations because of the numerous NO3- sources, the wide isotopic ranges, and the existing isotopic fractionations. In this study, we outline a combined procedure for improving the determination of NO3- sources in a paddy agriculture-urban gradient watershed in eastern China. First, the main sources of NO3- in the Qinhuai River were examined by the dual-isotope biplot approach, in which we narrowed the isotope ranges using site-specific isotopic results. Next, the bacterial groups and chemical properties of the river water were analyzed to verify these sources. Finally, we introduced a Bayesian model to apportion the spatiotemporal variations of the NO3- sources. Denitrification was first incorporated into the Bayesian model because denitrification plays an important role in the nitrogen pathway. The results showed that fertilizer contributed large amounts of NO3- to the surface water in traditional agricultural regions, whereas manure effluents were the dominant NO3- source in intensified agricultural regions, especially during the wet seasons. Sewage effluents were important in all three land uses and exhibited great differences between the dry season and the wet season. This combined analysis quantitatively delineates the proportion of NO3- sources from paddy agriculture to urban river water for both dry and wet seasons and incorporates isotopic fractionation and uncertainties in the source compositions.

  2. Game Models on Optimal Strategies in a Tourism Dual-Channel Supply Chain

    Directory of Open Access Journals (Sweden)

    Lei Yang

    2016-01-01

    Full Text Available This paper explores a two-echelon tourism supply chain consisting of a hotel and an online travel agency. The upside hotel rooms can be sold through the downside hotel alliance and online travel agency. The hotel alliance, selling rooms at a lower price, is a direct sale platform with a negligible entry fee. Notwithstanding, the online travel agency sells the room at a higher price with related personalized service. Customers will be refunded partially in case of their cancellation or no-show. An integrated model and two decentralized models based on Bertrand and Stackelberg games are developed, respectively. The results show that when the wholesale price is lower than a certain value, both the hotel and the online travel agency can gain more profit from the Stackelberg game than that from the Bertrand game. In the case that the hotel allows overbooking, the optimal overbooking quantity is obtained. If the overbooking proportion is too high, overbooking is profitable for the hotel only when the overbooking cost is lower than a certain value. At the end of the study, some experiments are conducted to analyze the sensitivity of the optimal prices and profits in the light of certain parameters.

  3. A dual-stage moderated mediation model linking authoritarian leadership to follower outcomes.

    Science.gov (United States)

    Schaubroeck, John M; Shen, Yimo; Chong, Sinhui

    2017-02-01

    Although authoritarian leadership is viewed pejoratively in the literature, in general it is not strongly related to important follower outcomes. We argue that relationships between authoritarian leadership and individual employee outcomes are mediated by perceived insider status, yet in different ways depending on work unit power distance climate and individual role breadth self-efficacy. Results from technology company employees in China largely supported our hypothesized model. We observed negative indirect effects of authoritarian leadership on job performance, affective organizational commitment, and intention to stay among employees in units with relatively low endorsement of power distance, whereas the indirect relationships were not significant among employees in relatively high power distance units. These conditional indirect effects of authoritarian leadership on performance and intention to stay were significantly stronger among employees with relatively high role breadth self-efficacy. We discuss how the model and findings promote understanding of how, and under what circumstances, authoritarian leadership may influence followers' performance and psychological connections to their organizations. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  4. Quasi-dimensional modeling of a fast-burn combustion dual-plug spark-ignition engine with complex combustion chamber geometries

    International Nuclear Information System (INIS)

    Altın, İsmail; Bilgin, Atilla

    2015-01-01

    This study builds on a previous parametric investigation using a thermodynamic-based quasi-dimensional (QD) cycle simulation of a spark-ignition (SI) engine with dual-spark plugs. The previous work examined the effects of plug-number and location on some performance parameters considering an engine with a simple cylindrical disc-shaped combustion chamber. In order to provide QD thermodynamic models applicable to complex combustion chamber geometries, a novel approach is considered here: flame-maps, which utilizes a computer aided design (CAD) software (SolidWorks). Flame maps are produced by the CAD software, which comprise all the possible flame radiuses with an increment of one-mm between them, according to the spark plug positions, spark timing, and piston position near the top dead center. The data are tabulated and stored as matrices. Then, these tabulated data are adapted to the previously reported cycle simulation. After testing for simple disc-shaped chamber geometries, the simulation is applied to a real production automobile (Honda-Fit) engine to perform the parametric study. - Highlights: • QD model was applied in dual plug engine with complex realistic combustion chamber. • This method successfully modeled the combustion in the dual-plug Honda-Fit engine. • The same combustion chamber is tested for various spark plug(s) locations. • The centrally located single spark-plug results in the fastest combustion

  5. Are Creative Individuals Bad Apples? A Dual Pathway Model of Unethical Behavior.

    Science.gov (United States)

    Keem, Sejin; Shalley, Christina E; Kim, Eugene; Jeong, Inseong

    2017-12-14

    Research has been inconsistent in its quest to discover whether dispositional creativity is associated with more or less unethical behavior. Drawing on social cognitive theory, we propose that moral disengagement and moral imagination are 2 parallel mechanisms that encourage or inhibit unethical behavior, and that which of these mediation processes occur depends on moral identity. Study 1, a 3-wave study of a food service organization, shows that employees high on both dispositional creativity and moral identity are less likely to be morally disengaged and behave less unethically. The results of Study 2 replicate Study 1's findings in a scenario-based study of college students, and further show that individuals who are high on both dispositional creativity and moral identity are more likely to be morally imaginative and to behave less unethically. Theoretical and practical implications of our model are discussed. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  6. DualTrust: A Trust Management Model for Swarm-Based Autonomic Computing Systems

    Energy Technology Data Exchange (ETDEWEB)

    Maiden, Wendy M. [Washington State Univ., Pullman, WA (United States)

    2010-05-01

    Trust management techniques must be adapted to the unique needs of the application architectures and problem domains to which they are applied. For autonomic computing systems that utilize mobile agents and ant colony algorithms for their sensor layer, certain characteristics of the mobile agent ant swarm -- their lightweight, ephemeral nature and indirect communication -- make this adaptation especially challenging. This thesis looks at the trust issues and opportunities in swarm-based autonomic computing systems and finds that by monitoring the trustworthiness of the autonomic managers rather than the swarming sensors, the trust management problem becomes much more scalable and still serves to protect the swarm. After analyzing the applicability of trust management research as it has been applied to architectures with similar characteristics, this thesis specifies the required characteristics for trust management mechanisms used to monitor the trustworthiness of entities in a swarm-based autonomic computing system and describes a trust model that meets these requirements.

  7. Modeling of Single and Dual Reservoir Porous Media Compressed Gas (Air and CO2) Storage Systems

    Science.gov (United States)

    Oldenburg, C. M.; Liu, H.; Borgia, A.; Pan, L.

    2017-12-01

    Intermittent renewable energy sources are causing increasing demand for energy storage. The deep subsurface offers promising opportunities for energy storage because it can safely contain high-pressure gases. Porous media compressed air energy storage (PM-CAES) is one approach, although the only facilities in operation are in caverns (C-CAES) rather than porous media. Just like in C-CAES, PM-CAES operates generally by injecting working gas (air) through well(s) into the reservoir compressing the cushion gas (existing air in the reservoir). During energy recovery, high-pressure air from the reservoir is mixed with fuel in a combustion turbine to produce electricity, thereby reducing compression costs. Unlike in C-CAES, the storage of energy in PM-CAES occurs variably across pressure gradients in the formation, while the solid grains of the matrix can release/store heat. Because air is the working gas, PM-CAES has fairly low thermal efficiency and low energy storage density. To improve the energy storage density, we have conceived and modeled a closed-loop two-reservoir compressed CO2 energy storage system. One reservoir is the low-pressure reservoir, and the other is the high-pressure reservoir. CO2 is cycled back and forth between reservoirs depending on whether energy needs to be stored or recovered. We have carried out thermodynamic and parametric analyses of the performance of an idealized two-reservoir CO2 energy storage system under supercritical and transcritical conditions for CO2 using a steady-state model. Results show that the transcritical compressed CO2 energy storage system has higher round-trip efficiency and exergy efficiency, and larger energy storage density than the supercritical compressed CO2 energy storage. However, the configuration of supercritical compressed CO2 energy storage is simpler, and the energy storage densities of the two systems are both higher than that of PM-CAES, which is advantageous in terms of storage volume for a given

  8. Modeling elite male athletes' peripheral bone mass, assessed using regional dual x-ray absorptiometry.

    Science.gov (United States)

    Nevill, A M; Holder, R L; Stewart, A D

    2003-01-01

    There is still considerable debate as to whether bone mineral content (BMC) increases in proportion to the projected bone area, A(p), or an estimate of the skeletal bone volume, (A(p))(3/2), being assessed. The results from this study suggest that the bone mass acquisition of elite athletes' arms and legs increases in proportion to the projected bone area, A(p), having simultaneously controlled/removed the effect of the confounding variables of body mass and body fat. Although this supports the use of the traditional bone mineral density ratio (BMD=BMC/A(p)), it also highlights the dangers of overlooking the effect of known confounding variables. Ignoring the effect of such confounding variables, athletic groups whose activities involve upper body strength (rugby, rock climbing, kayaking, weight lifting) had the highest arm BMD, while runners were observed to have the lowest arm BMD (lower than that of the controls). Similarly, leg BMD was highest in rugby players, whose activities included both running and strength training. However, the rugby players were also observed to have the greatest body mass. When the important determinants of body mass, body fat, as well as projected bone area, A(p), were incorporated as covariates into a proportional allometric ANCOVA model for BMC, different conclusions were obtained. The introduction of these covariates had the effect of reducing the sporting differences on adjusted arm BMC, although the "sport" by "side" interaction still identified racket players as the only group with a greater dominant arm BMC (P benefits of activity on peripheral bone mass as being site-specific but reinforce the dangers of making generalizations about the relative benefits of different exercises ignoring the effects of known confounding variables, such as body size, body composition, and age.

  9. Characterization of ignition transient processes in kerosene-fueled model scramjet engine by dual-pulse laser-induced plasma

    Science.gov (United States)

    Li, Xipeng; Liu, Weidong; Pan, Yu; Yang, Leichao; An, Bin; Zhu, Jiajian

    2018-03-01

    Dual-pulse laser-induced plasma ignition of kerosene in cavity at model scramjet engine is studied. The simulated flight condition is Ma 6 at 30 km, and the isolator entrance has a Mach number of 2.92, a total pressure of 2.6 MPa and a stagnation temperature of 1650 K. Two independent laser pulses at 532 nm with a pulse width of 10 ns, a diameter of 12 mm and a maximum energy of 300 mJ are focused into cavity for ignition. The flame structure and propagation during transient ignition processes are captured by simultaneous CH* and OH* chemiluminescence imaging. The entire ignition process of kerosene can be divided into five stages, which are referred as turbulent dissipation stage, quasi-stable state, combustion enhancement stage, reverting stage and combustion stabilization stage. A local closed loop of propagations of the burning mixtures from the shear layer into the recirculation zone of cavity is revealed, which the large-scale eddy in the shear layer plays a key role. The enhancement of mass exchange between shear layer and the recirculation zone of cavity could promote the flame propagation process and enhance the ignition capability as well as extend the ignition limits. A cavity shear-layer stabilized combustion of kerosene is established in the supersonic flow roughly 3.3 ms after the laser pulse. Chemical reactions mainly occur in the shear layer and the near-wall zone downstream of the cavity. The distribution of OH* is thicker than CH* at stable combustion condition.

  10. An inverse model for locating skin tumours in 3D using the genetic algorithm with the Dual Reciprocity Boundary Element Method

    Directory of Open Access Journals (Sweden)

    Fabrício Ribeiro Bueno

    Full Text Available Here, the Dual Reciprocity Boundary Element Method is used to solve the 3D Pennes Bioheat Equation, which together with a Genetic Algorithm, produces an inverse model capable of obtaining the location and the size of a tumour, having as data input the temperature distribution measured on the skin surface. Given that the objective function, which is solved inversely, involves the DRBEM (Dual Reciprocity Boundary Element Method the Genetic Algorithm in its usual form becomes slower, in such a way that it was necessary to develop functions based the solution history in order that the process becomes quicker and more accurate. Results for 8 examples are presented including cases with convection and radiation boundary conditions. Cases involving noise in the readings of the equipment are also considered. This technique is intended to assist health workers in the diagnosis of tumours.

  11. A Dual-Continuum Model for Brine Migration in Salt Associated with Heat-Generating Nuclear Waste: Fully Coupled Thermal-Hydro-Mechanical Analysis

    Science.gov (United States)

    Hu, M.; Rutqvist, J.

    2017-12-01

    The disposal of heat-generating nuclear waste in salt host rock establishes a thermal gradient around the waste package that may cause brine inclusions in the salt grains to migrate toward the waste package. In this study, a dual-continuum model is developed to analyze such a phenomenon. This model is based on the Finite Volume Method (FVM), and it is fully thermal-hydro-mechanical (THM) coupled. For fluid flow, the dual-continuum model considers flow in the interconnected pore space and also in the salt grains. The mass balance of salt and water in these two continua is separately established, and their coupling is represented by flux associated with brine migration. Together with energy balance, such a system produces a coupled TH model with strongly nonlinear features. For mechanical analysis, a new formulation is developed based on the Voronoi tessellated mesh. By relating each cell to several connected triangles, first-order approximation is constructed. The coupling between thermal and mechanical fields is only considered in terms of thermal expansion. And the coupling between the hydraulic and mechanical fields in terms of pore-volume effects is consistent with Biot's theory. Therefore, a fully coupled THM model is developed. Several demonstration examples are provided to verify the model. Last the new model is applied to analyze coupled THM behavior and the results are compared with experimental data.

  12. Development of a short version of the dual process model scales: right-wing authoritarianism, social dominance orientation, dangerous and competitive worldviews

    Directory of Open Access Journals (Sweden)

    Dmitry S. Grigoryev

    2017-12-01

    Full Text Available Objective. The article describes a short version of the dual process model scales by J. Duckitt that allow elaborating on an integrated exploratory approach for the assessment of authoritarianism. Background. This area of research is not widespread in Russia in contrast to foreign social psychology. Unfortunately, there are only a few studies in Russia that advance our understanding of the indicated problems, and these few studies likely put more questions than give answers. It can be partly explained by the lack of appropriate available, reliable and valid measures in Russian. Dual process model for the study of authoritarianism offers the scales designed to measure: (1 right-wing authoritarianism that reflects the motivation and attitudes to maintain and preservation of the social cohesion, order, stability, and collective security; (2 social dominance orientation that reflects the motivation and attitudes to maintain and preservation of the dominance and superiority; (3 dangerous worldview that reflects views of the social world as the dangerous and threatening; and (4 competitive worldview that reflects views of the social world as the competitive and ferocious. Design. The data for the analysis were collected in the survey of 241 participants, mostly residents of Moscow (Central Federal District, Russia, and Ulyanovsk (Volga Federal District, Russia. Using confirmatory factor analysis the four measurement models containing the different number of dimensions of the short version of the dual process model scales were tested. Also, cross-validation was performed (N = 576. Results. The tested measurement models had acceptable reliability and validity indices. However, the best fit was shown by the model with multidimensional structure in which all the subfactors were as separate constructs. Conclusion. The short version of scales was successfully compiled, the measures can be considered a reliable and valid measure to study of authoritarianism

  13. NLM Grantee's "HealthMap" Helps Uncover Measles Vaccination Gap

    Science.gov (United States)

    ... courtesy of NLM NLM Grantee's "HealthMap" Helps Uncover Measles Vaccination Gap Inadequate vaccine coverage is likely a driving force behind the ongoing Disneyland measles outbreak, according to calculations by a research team ...

  14. Certified dual-corrected radiation patterns of phased antenna arrays by offline–online order reduction of finite-element models

    International Nuclear Information System (INIS)

    Sommer, A.; Farle, O.; Dyczij-Edlinger, R.

    2015-01-01

    This paper presents a fast numerical method for computing certified far-field patterns of phased antenna arrays over broad frequency bands as well as wide ranges of steering and look angles. The proposed scheme combines finite-element analysis, dual-corrected model-order reduction, and empirical interpolation. To assure the reliability of the results, improved a posteriori error bounds for the radiated power and directive gain are derived. Both the reduced-order model and the error-bounds algorithm feature offline–online decomposition. A real-world example is provided to demonstrate the efficiency and accuracy of the suggested approach

  15. Massive violent death and contested national mourning in post-authoritarian Chile and Argentina: a sociocultural application of the dual process model.

    Science.gov (United States)

    Robben, Antonius C G M

    2014-01-01

    This article uses the dual process model (DPM) in an analysis of the national mourning of tens of thousands of disappeared in Chile and Argentina by adapting the model from the individual to the collective level where society as a whole is bereaved. Perpetrators are also involved in the national mourning process as members of a bereaved society. This article aims to (a) demonstrate the DPMs significance for the analysis of national mourning in post-conflict societies and (b) explain oscillations between loss orientation and restoration orientation in coping with massive losses that seem contradictory from a grief work perspective.

  16. Consolidity: Mystery of inner property of systems uncovered

    Directory of Open Access Journals (Sweden)

    Hassen T. Dorrah

    2012-10-01

    Full Text Available This paper uncovers the mystery of consolidity, an inner property of systems that was amazingly hidden. Consolidity also reveals the secrecy of why strong stable and highly controllable systems are not invulnerable of falling and collapsing. Consolidity is measured by its Consolidity Index, defined as the ratio of overall changes of output parameters over combined changes of input and system parameters, all operating in fully fuzzy environment. Under this notion, systems are classified into consolidated, quasi-consolidated, neutrally consolidated, unconsolidated, quasi-unconsolidated and mixed types. The strategy for the implementation of consolidity is elaborated for both natural and man-made existing systems as well as the new developed ones. An important critique arises that the by-product consolidity of natural or built-as-usual system could lead to trapping such systems into a completely undesired unconsolidity. This suggests that the ample number of conventional techniques that do not take system consolidity into account should gradually be changed, and adjusted with improved consolidity-based techniques. Four Golden Rules are highlighted for handling system consolidity, and applied to several illustrative case studies. These case studies cover the consolidity analysis of the Drug Concentration problem, Predator-Prey Population problem, Spread of Infectious Disease problem, AIDS Epidemic problem and Arm Race model. It is demonstrated that consolidity changes are contrary (opposite in sign to changes of both stability and controllability. This is a very significant result showing that our present practice of stressing on building strong stable and highly controllable systems could have already jeopardized the consolidity behavior of an ample family of existing real life systems. It is strongly recommended that the four Golden Rules of consolidity should be enforced as future strict regulations of systems modeling, analysis, design and

  17. Some properties of dual and approximate dual of fusion frames

    OpenAIRE

    Arefijamaal, Ali Akbar; Neyshaburi, Fahimeh Arabyani

    2016-01-01

    In this paper we extend the notion of approximate dual to fusion frames and present some approaches to obtain dual and approximate alternate dual fusion frames. Also, we study the stability of dual and approximate alternate dual fusion frames.

  18. Subsurface Flow Modeling in Single and Dual Continuum Anisotropic Porous Media using the Multipoint Flux Approximation Method

    KAUST Repository

    Negara, Ardiansyah

    2015-05-01

    Anisotropy of hydraulic properties of the subsurface geologic formations is an essential feature that has been established as a consequence of the different geologic processes that undergo during the longer geologic time scale. With respect to subsurface reservoirs, in many cases, anisotropy plays significant role in dictating the direction of flow that becomes no longer dependent only on driving forces like the pressure gradient and gravity but also on the principal directions of anisotropy. Therefore, there has been a great deal of motivation to consider anisotropy into the subsurface flow and transport models. In this dissertation, we present subsurface flow modeling in single and dual continuum anisotropic porous media, which include the single-phase groundwater flow coupled with the solute transport in anisotropic porous media, the two-phase flow with gravity effect in anisotropic porous media, and the natural gas flow in anisotropic shale reservoirs. We have employed the multipoint flux approximation (MPFA) method to handle anisotropy in the flow model. The MPFA method is designed to provide correct discretization of the flow equations for general orientation of the principal directions of the permeability tensor. The implementation of MPFA method is combined with the experimenting pressure field approach, a newly developed technique that enables the solution of the global problem breaks down into the solution of multitude of local problems. The numerical results of the study demonstrate the significant effects of anisotropy of the subsurface formations. For the single-phase groundwater flow coupled with the solute transport modeling in anisotropic porous media, the results shows the strong impact of anisotropy on the pressure field and the migration of the solute concentration. For the two-phase flow modeling with gravity effect in anisotropic porous media, it is observed that the buoyancy-driven flow, which emerges due to the density differences between the

  19. Is empathy one of the Big Three? Identifying its role in a dual-process model of ideology and blatant and subtle prejudice

    Science.gov (United States)

    2018-01-01

    In the field of the social psychology of prejudice, John Duckitt's Dual-Process Cognitive-Motivational Model of Ideology and Prejudice has gained a firm grounding over the past decade and a half, while empathy has become one of the most powerful predictors of prejudice, alongside right-wing authoritarianism and social dominance orientation. This study integrates empathy into the dual-process model, exploring the effects of this variable, along with the impact of personality and ideological attitudes, on prejudice in both its blatant and subtle forms. A cross-sectional research design was used to collect data from 260 university students by self-report measures. Despite its cross-sectional nature, a pattern of causal relationships was hypothesized according to experimental and longitudinal findings from previous studies. The path analysis results show that in the model fitted to the data, empathy does not have any direct impact on prejudice, although it plays a significant role in the prediction of prejudice towards a particular immigrant group. On the other hand, the dual-process model is confirmed in the explanation of blatant prejudice and, in a weaker and indirect way, of subtle prejudice; sustaining the distinctive nature of these constructs on some differential predictors and paths. In the discussion, this study proposes that when ideological and personality-based variables are both included in the model, general empathy is not so robust in the explanation of prejudice, since some of the empathetic components might become diluted among other covariates. But even so, its indirect effectiveness through personality and ideological attitudes remains relevant. PMID:29621307

  20. On the synthesis of a bio-inspired dual-cellular fluidic flexible matrix composite adaptive structure based on a non-dimensional dynamics model

    International Nuclear Information System (INIS)

    Li, Suyi; Wang, K W

    2013-01-01

    A recent study investigated the dynamic characteristics of an adaptive structure concept featuring dual fluidic flexible matrix composite (F 2 MC) cells inspired by the configuration of plant cells and cell walls. This novel bio-inspired system consists of two F 2 MC cells with different fiber angles connected through internal fluid circuits. It was discovered that the dual F 2 MC cellular structure can be characterized as a two degree of freedom damped mass–spring oscillator, and can be utilized as a vibration absorber or an enhanced actuator under different operation conditions. These results demonstrated that the concept is promising and further investigations are needed to develop methodologies for synthesizing future multi-cellular F 2 MC structural systems. While interesting, the previous study focused on specific case studies and analysis. That is, the outcome did not provide insight that could be generalized, or tools for synthesizing a multiple F 2 MC cellular structure. This paper attempts to address this important issue by developing a non-dimensional dynamic model, which reveals good physical insights as well as identifying crucial constitutive parameters for F 2 MC cellular design. Working with these parameters, rather than physical variables, can greatly simplify the mathematics involved in the study. A synthesis tool is then developed for the dual-cellular structure, and it is found that for each set of achievable target poles and zero, there exist multiple F 2 MC cellular designs, forming a design space. The presented physical insights and synthesis tool for the dual-cellular structure will be the building blocks for future investigation on cellular structures with a larger number of cells. (paper)

  1. Telmisartan in the diabetic murine model of acute myocardial infarction: dual contrast manganese-enhanced and delayed enhancement MRI evaluation of the peri-infarct region.

    Science.gov (United States)

    Toma, Ildiko; Kim, Paul J; Dash, Rajesh; McConnell, Michael V; Nishimura, Dwight; Harnish, Phillip; Yang, Phillip C

    2016-02-05

    A novel MRI technique, employing dual contrast manganese-enhanced MRI (MEMRI) and delayed enhancement MRI (DEMRI), can evaluate the physiologically unstable peri-infarct region. Dual contrast MEMRI-DEMRI enables comprehensive evaluation of telmisartan to salvage the peri-infarct injury to elucidate the underlying mechanism of restoring the ischemic cardiomyopathy in the diabetic mouse model. Dual contrast MEMRI-DEMRI was performed on weeks 1, 2, and 4 following initiation of telmisartan treatment in 24 left anterior descendent artery ligated diabetic mice. The MRI images were analyzed for core infarct, peri-infarct, left ventricular end-diastolic, end-systolic volumes, and the left ventricular ejection fraction (LVEF). Transmission electron microscopy (TEM) and real-time PCR were used for ex vivo analysis of the myocardium. Telmisartan vs. control groups demonstrated significantly improved LVEF at weeks 1, 2, and 4, respectively (33 ± 7 %*** vs. 19 ± 5 %, 29 ± 3 %*** vs. 22 ± 4 %, and 31 ± 2 %*** vs 18 ± 6 %, ***p infarct injury. Telmisartan group significantly salvaged the peri-infarct injury. The myocardial effects were validated by TEM, which confirmed the presence of the injured but viable cardiomyocyte morphology in the peri-infarct region and by flow cytometry of venous blood, which demonstrated significantly increased circulating endothelial progenitor cells (EPCs). The improved cardiac function in ischemic cardiomyopathy of diabetic mice by telmisartan is attributed to the attenuation of the peri-infarct injury by the angiogenic effects of EPCs to salvage the injured cardiomyocytes. Dual-contrast MEMRI-DEMRI technique tracked the therapeutic effects of telmisartan on the injured myocardium longitudinally.

  2. New Analytical Model for Short-Channel Fully Depleted Dual-Material-Gate Silicon-on-Insulator Metal-Oxide-Semiconductor Field-Effect Transistors

    Science.gov (United States)

    Te-Kuang Chiang,

    2010-07-01

    Using the exact solution of the two-dimensional Poisson equation, a new analytical model comprising two-dimensional potential and threshold voltage for short-channel fully depleted dual-material-gate silicon-on-insulator (SOI) metal-oxide-semiconductor field-effect transistors (MOSFETs) is developed. The model shows that the minimum acceptable channel length can be sustained while repressing the short-channel effects if a thin gate oxide and a thin silicon body are employed in the device. Moreover, by increasing the ratio of the screen gate length to control gate length, the threshold voltage roll-off can be more effectively reduced. The model is verified by the close agreement of its results with those of a numerical simulation using the device simulator MEDICI. The model not only offers an insight into the device physics but is also an efficient model for circuit simulation.

  3. Thermal Behavior of a Single Spent Fuel in Water Pool Storage Under Partially Uncovered Condition

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Woo Ram; Park, Hee Sung; Song, Sub Lee; Lee, Jae Young [Handong Global Univ, Pohang (Korea, Republic of)

    2015-10-15

    LOCA in SFP can be led by a partial drain-down or a boil off scenario. In order to predict the response and consequence in such case, exact model on the partially uncovered SFP has to be established. Most studies on accidents in SFP have been done by safety analysis codes such as ATHLET-CD, ASTEC, MAAP, and MELCOR. However, an experimental investigation has not been conducted so far. Schultz et al.(2014) studied experimentally the response of air cooled BWR fuel assembly which is blocked at lower side fluid path. In this study, we experimentally investigated the thermal response of a partially uncovered single nuclear fuel rod (SNFR) in the SFP. The SNFR was 1/4 scaled down in axial length. 1-dimensional numerical analysis model was developed and compared with the result of experiment. An experimental study was conducted for obtaining transient temperature profile data of a modeled single nuclear fuel rod in heating condition under partially uncovered condition. Numerical prediction model was developed also and the prediction result was compared with the experimental result.

  4. WE-FG-206-06: Dual-Input Tracer Kinetic Modeling and Its Analog Implementation for Dynamic Contrast-Enhanced (DCE-) MRI of Malignant Mesothelioma (MPM)

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S; Rimner, A; Hayes, S; Hunt, M; Deasy, J; Zauderer, M; Rusch, V; Tyagi, N [Memorial Sloan Kettering Cancer Center, New York, NY (United States)

    2016-06-15

    Purpose: To use dual-input tracer kinetic modeling of the lung for mapping spatial heterogeneity of various kinetic parameters in malignant MPM Methods: Six MPM patients received DCE-MRI as part of their radiation therapy simulation scan. 5 patients had the epitheloid subtype of MPM, while one was biphasic. A 3D fast-field echo sequence with TR/TE/Flip angle of 3.62ms/1.69ms/15° was used for DCE-MRI acquisition. The scan was collected for 5 minutes with a temporal resolution of 5-9 seconds depending on the spatial extent of the tumor. A principal component analysis-based groupwise deformable registration was used to co-register all the DCE-MRI series for motion compensation. All the images were analyzed using five different dual-input tracer kinetic models implemented in analog continuous-time formalism: the Tofts-Kety (TK), extended TK (ETK), two compartment exchange (2CX), adiabatic approximation to the tissue homogeneity (AATH), and distributed parameter (DP) models. The following parameters were computed for each model: total blood flow (BF), pulmonary flow fraction (γ), pulmonary blood flow (BF-pa), systemic blood flow (BF-a), blood volume (BV), mean transit time (MTT), permeability-surface area product (PS), fractional interstitial volume (vi), extraction fraction (E), volume transfer constant (Ktrans) and efflux rate constant (kep). Results: Although the majority of patients had epitheloid histologies, kinetic parameter values varied across different models. One patient showed a higher total BF value in all models among the epitheloid histologies, although the γ value was varying among these different models. In one tumor with a large area of necrosis, the TK and ETK models showed higher E, Ktrans, and kep values and lower interstitial volume as compared to AATH and DP and 2CX models. Kinetic parameters such as BF-pa, BF-a, PS, Ktrans values were higher in surviving group compared to non-surviving group across most models. Conclusion: Dual-input tracer

  5. Collateral ventilation quantification using xenon-enhanced dynamic dual-energy CT: Differences between canine and swine models of bronchial occlusion

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun Ah; Goo, Jin Mo; Park, Sang Joon; Lee, Chang Hyun; Park, Chng Min [Dept. of Radiology, Seoul National University College of Medicine and Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul (Korea, Republic of)

    2015-06-15

    The aim of this study was to evaluate whether the difference in the degree of collateral ventilation between canine and swine models of bronchial obstruction could be detected by using xenon-enhanced dynamic dual-energy CT. Eight mongrel dogs and six pigs underwent dynamic dual-energy scanning of 64-slice dual-source CT at 12-second interval for 2-minute wash-in period (60% xenon) and at 24-second interval for 3-minute wash-out period with segmental bronchus occluded. Ventilation parameters of magnitude (A value), maximal slope, velocity (K value), and time-to-peak (TTP) enhancement were calculated from dynamic xenon maps using exponential function of Kety model. A larger difference in A value between parenchyma was observed in pigs than in dogs (absolute difference, -33.0 +/- 5.0 Hounsfield units [HU] vs. -2.8 +/- 7.1 HU, p = 0.001; normalized percentage difference, -79.8 +/- 1.8% vs. -5.4 +/- 16.4%, p = 0.0007). Mean maximal slopes in both periods in the occluded parenchyma only decreased in pigs (all p < 0.05). K values of both periods were not different (p = 0.892) in dogs. However, a significant (p = 0.027) difference was found in pigs in the wash-in period. TTP was delayed in the occluded parenchyma in pigs (p = 0.013) but not in dogs (p = 0.892). Xenon-ventilation CT allows the quantification of collateral ventilation and detection of differences between canine and swine models of bronchial obstruction.

  6. Collateral ventilation quantification using xenon-enhanced dynamic dual-energy CT: Differences between canine and swine models of bronchial occlusion

    International Nuclear Information System (INIS)

    Kim, Eun Ah; Goo, Jin Mo; Park, Sang Joon; Lee, Chang Hyun; Park, Chng Min

    2015-01-01

    The aim of this study was to evaluate whether the difference in the degree of collateral ventilation between canine and swine models of bronchial obstruction could be detected by using xenon-enhanced dynamic dual-energy CT. Eight mongrel dogs and six pigs underwent dynamic dual-energy scanning of 64-slice dual-source CT at 12-second interval for 2-minute wash-in period (60% xenon) and at 24-second interval for 3-minute wash-out period with segmental bronchus occluded. Ventilation parameters of magnitude (A value), maximal slope, velocity (K value), and time-to-peak (TTP) enhancement were calculated from dynamic xenon maps using exponential function of Kety model. A larger difference in A value between parenchyma was observed in pigs than in dogs (absolute difference, -33.0 +/- 5.0 Hounsfield units [HU] vs. -2.8 +/- 7.1 HU, p = 0.001; normalized percentage difference, -79.8 +/- 1.8% vs. -5.4 +/- 16.4%, p = 0.0007). Mean maximal slopes in both periods in the occluded parenchyma only decreased in pigs (all p < 0.05). K values of both periods were not different (p = 0.892) in dogs. However, a significant (p = 0.027) difference was found in pigs in the wash-in period. TTP was delayed in the occluded parenchyma in pigs (p = 0.013) but not in dogs (p = 0.892). Xenon-ventilation CT allows the quantification of collateral ventilation and detection of differences between canine and swine models of bronchial obstruction.

  7. Synthesis, biological evaluation and molecular modeling of novel thienopyrimidinone and triazolothienopyrimidinone derivatives as dual anti-inflammatory antimicrobial agents.

    Science.gov (United States)

    Bekhit, Adnan A; Farghaly, Ahmed M; Shafik, Ragab M; Elsemary, Mona M A; Bekhit, Alaa El-Din A; Guemei, Aida A; El-Shoukrofy, Mai S; Ibrahim, Tamer M

    2018-04-01

    New thienopyrimidinone and triazolothienopyrimidinone derivatives have been synthesized. These compounds were subjected to anti-inflammatory and antimicrobial activity screening aiming to identify new candidates that have dual anti-inflammatory and antimicrobial activities. Compounds 5, 7 and 10a showed minimal ulcerogenic effect and high selectivity towards human recombinant COX-2 over COX-1 enzyme. Their docking outcome correlated with their biological activity and assured the high selectivity binding towards COX-2. In addition, they could act safely up to 80 mg/kg orally or 40 mg/kg parentrally. The antimicrobial screening showed that compound 10a displayed distinctive inhibitory effect on the growth of Escherichia coli comparable to that of ampicillin. Moreover, compounds 5, 7, 9 and 12a possessed 50% of the inhibitory activity of ampicillin against E. coli. Thus, compounds 5, 7 and 10a represent promising dual acting anti-inflammatory and antimicrobial agents. This work provides rewarding template enriching the chemical space for dual anti-inflammatory anti-microbial activities. Copyright © 2018 Elsevier Inc. All rights reserved.

  8. Dual Delivery of rhPDGF-BB and Bone Marrow Mesenchymal Stromal Cells Expressing the BMP2 Gene Enhance Bone Formation in a Critical-Sized Defect Model

    Science.gov (United States)

    Park, Shin-Young; Kim, Kyoung-Hwa; Shin, Seung-Yun; Koo, Ki-Tae; Lee, Yong-Moo

    2013-01-01

    Bone tissue healing is a dynamic, orchestrated process that relies on multiple growth factors and cell types. Platelet-derived growth factor-BB (PDGF-BB) is released from platelets at wound sites and induces cellular migration and proliferation necessary for bone regeneration in the early healing process. Bone morphogenetic protein-2 (BMP-2), the most potent osteogenic differentiation inducer, directs new bone formation at the sites of bone defects. This study evaluated a combinatorial treatment protocol of PDGF-BB and BMP-2 on bone healing in a critical-sized defect model. To mimic the bone tissue healing process, a dual delivery approach was designed to deliver the rhPDGF-BB protein transiently during the early healing phase, whereas BMP-2 was supplied by rat bone marrow stromal cells (BMSCs) transfected with an adenoviral vector containing the BMP2 gene (AdBMP2) for prolonged release throughout the healing process. In in vitro experiments, the dual delivery of rhPDGF-BB and BMP2 significantly enhanced cell proliferation. However, the osteogenic differentiation of BMSCs was significantly suppressed even though the amount of BMP-2 secreted by the AdBMP2-transfected BMSCs was not significantly affected by the rhPDGF-BB treatment. In addition, dual delivery inhibited the mRNA expression of BMP receptor type II and Noggin in BMSCs. In in vivo experiments, critical-sized calvarial defects in rats showed enhanced bone regeneration by dual delivery of autologous AdBMP2-transfected BMSCs and rhPDGF-BB in both the amount of new bone formed and the bone mineral density. These enhancements in bone regeneration were greater than those observed in the group treated with AdBMP2-transfected BMSCs alone. In conclusion, the dual delivery of rhPDGF-BB and AdBMP2-transfected BMSCs improved the quality of the regenerated bone, possibly due to the modulation of PDGF-BB on BMP-2-induced osteogenesis. PMID:23901900

  9. Mathematical model for the preliminary analysis of dual-mode space nuclear fission solid core power and propulsion systems, NUROC3A. AMS report No. 1239a

    Energy Technology Data Exchange (ETDEWEB)

    Grey, J.; Chow, S.

    1976-06-30

    The three-volume report describes a dual-mode nuclear space power and propulsion system concept that employs an advanced solid-core nuclear fission reactor coupled via heat pipes to one of several electric power conversion systems. Such a concept could be particularly useful for missions which require both relatively high acceleration (e.g., for planetocentric maneuvers) and high performance at low acceleration (e.g., on heliocentric trajectories or for trajectory shaping). The first volume develops the mathematical model of the system.

  10. The discharge behavior of lithium-ion batteries using the Dual-Potential Multi-Scale Multi-Dimensional (MSMD) Battery Model

    DEFF Research Database (Denmark)

    Saeed Madani, Seyed; Swierczynski, Maciej Jozef; Kær, Søren Knudsen

    2017-01-01

    plot of maximum temperature in the domain and maximum temperature in the area are illustrated. Additionally, an external and internal short-circuit treatment for three cases have been studied. The Dual-Potential Multi-Scale Multi-Dimensional (MSMD) Battery Model (BM) was used by ANSYS FLUENT software...... to analysis the discharge behaviour of lithium-ion batteries. The results show that surface monitor plot of discharge curve at 1 C has a decreasing trend and volume monitor plot of maximum temperature in the domain has slightly increasing pattern over the simulation time. For the curves of discharge...

  11. Data-Driven Control for Interlinked AC/DC Microgrids via Model-Free Adaptive Control and Dual-Droop Control

    DEFF Research Database (Denmark)

    Zhang, Huaguang; Zhou, Jianguo; Sun, Qiuye

    2017-01-01

    This paper investigates the coordinated power sharing issues of interlinked ac/dc microgrids. An appropriate control strategy is developed to control the interlinking converter (IC) to realize proportional power sharing between ac and dc microgrids. The proposed strategy mainly includes two parts......: the primary outer-loop dual-droop control method along with secondary control; the inner-loop data-driven model-free adaptive voltage control. Using the proposed scheme, the interlinking converter, just like the hierarchical controlled DG units, will have the ability to regulate and restore the dc terminal...

  12. System Dynamics Modeling as a Supporting Tool in order to Uncover Relevant KPI’s as well as Their Main Relations in the Process of Constructing a Balanced Scorecard

    DEFF Research Database (Denmark)

    Nielsen, Steen; Nielsen, Erland Hejn; Bjoern Pedersen, Lars

    , operational execution, feedback and learning are some of the most important key features of any performance measurement model (Argyris, 1976; Kaplan and Norton, 1996; Otley, 1999; Warren, 2005). By combining BSC with systems thinking as developed by Forrester in 1958, the present paper aims to address...... dynamics (SD) when setting themes, objectives and key performance indicators, a company can - at a very early stage in the process - begin to improve and develop its business acumen and understanding of how the company's balanced scorecard must be designed according to the strategy to be executed through...... the tool. SD-modelling tools in this phase are: the subsystem diagram, boundary chart and CLD (closed loop diagram). The output is CLD, containing the key performance indicators and variables that are central to the company's strategy. The next step is then to use the stock & flow idea, ending up...

  13. Uncovering the Dark Energy of Aging.

    Science.gov (United States)

    Melov, Simon

    2016-10-26

    A medically relevant understanding of aging requires an appreciation for how time degrades specific, healthy features of individual organisms over the course of their lives. Zach Pincus and colleagues make a key step in this direction, using C. elegans as a model system. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Numerical Investigation on the Heat Extraction Capacity of Dual Horizontal Wells in Enhanced Geothermal Systems Based on the 3-D THM Model

    Directory of Open Access Journals (Sweden)

    Zhixue Sun

    2018-01-01

    Full Text Available The Enhanced Geothermal System (EGS constructs an artificial thermal reservoir by hydraulic fracturing to extract heat economically from hot dry rock. As the core element of the EGS heat recovery process, mass and heat transfer of working fluid mainly occurs in fractures. Since the direction of the natural and induced fractures are generally perpendicular to the minimum principal stress in the formation, as an effective stimulation approach, horizontal well production could increase the contact area with the thermal reservoir significantly. In this paper, the thermal reservoir is developed by a dual horizontal well system and treated as a fractured porous medium composed of matrix rock and discrete fracture network. Using the local thermal non-equilibrium theory, a coupled THM mathematical model and an ideal 3D numerical model are established for the EGS heat extraction process. EGS heat extraction capacity is evaluated in the light of thermal recovery lifespan, average outlet temperature, heat production, electricity generation, energy efficiency and thermal recovery rate. The results show that with certain reservoir and production parameters, the heat production, electricity generation and thermal recovery lifespan can achieve the commercial goal of the dual horizontal well system, but the energy efficiency and overall thermal recovery rate are still at low levels. At last, this paper puts forward a series of optimizations to improve the heat extraction capacity, including production conditions and thermal reservoir construction design.

  15. Dual-mixed finite elements for the three-field Stokes model as a finite volume method on staggered grids

    KAUST Repository

    Kou, Jisheng

    2017-06-09

    In this paper, a new three-field weak formulation for Stokes problems is developed, and from this, a dual-mixed finite element method is proposed on a rectangular mesh. In the proposed mixed methods, the components of stress tensor are approximated by piecewise constant functions or Q1 functions, while the velocity and pressure are discretized by the lowest-order Raviart-Thomas element and the piecewise constant functions, respectively. Using quadrature rules, we demonstrate that this scheme can be reduced into a finite volume method on staggered grid, which is extensively used in computational fluid mechanics and engineering.

  16. On modelling of shear fracture in deep drawing of a high-strength dual-phase sheet steel

    OpenAIRE

    Behrens, B.-A.; Bonk, C.; Peshekhodov, I.

    2017-01-01

    The paper presents application of fracture behaviour characterisation results of a dual-phase sheet steel DP600 to an FEA of its deep-drawing for shear fracture prediction. The characterisation results were obtained with the help of a characterisation method based on a tensile test on a novel butterfly specimen and published previously by the authors. The aim of the present paper is to evaluate that characterisation method on a deep-drawing process. Based on the previous results of the author...

  17. Uncovering the Genetic Architectures of Quantitative Traits

    Directory of Open Access Journals (Sweden)

    James J. Lee

    2016-01-01

    Full Text Available The aim of a genome-wide association study (GWAS is to identify loci in the human genome affecting a phenotype of interest. This review summarizes some recent work on conceptual and methodological aspects of GWAS. The average effect of gene substitution at a given causal site in the genome is the key estimand in GWAS, and we argue for its fundamental importance. Implicit in the definition of average effect is a linear model relating genotype to phenotype. The fraction of the phenotypic variance ascribable to polymorphic sites with nonzero average effects in this linear model is called the heritability, and we describe methods for estimating this quantity from GWAS data. Finally, we show that the theory of compressed sensing can be used to provide a sharp estimate of the sample size required to identify essentially all sites contributing to the heritability of a given phenotype.

  18. Evaluation of differences between dual salt-pH gradient elution and mono gradient elution using a thermodynamic model: Simultaneous separation of six monoclonal antibody charge and size variants on preparative-scale ion exchange chromatographic resin.

    Science.gov (United States)

    Lee, Yi Feng; Jöhnck, Matthias; Frech, Christian

    2018-02-21

    The efficiencies of mono gradient elution and dual salt-pH gradient elution for separation of six mAb charge and size variants on a preparative-scale ion exchange chromatographic resin are compared in this study. Results showed that opposite dual salt-pH gradient elution with increasing pH gradient and simultaneously decreasing salt gradient is best suited for the separation of these mAb charge and size variants on Eshmuno ® CPX. Besides giving high binding capacity, this type of opposite dual salt-pH gradient also provides better resolved mAb variant peaks and lower conductivity in the elution pools compared to single pH or salt gradients. To have a mechanistic understanding of the differences in mAb variants retention behaviors of mono pH gradient, parallel dual salt-pH gradient, and opposite dual salt-pH gradient, a linear gradient elution model was used. After determining the model parameters using the linear gradient elution model, 2D plots were used to show the pH and salt dependencies of the reciprocals of distribution coefficient, equilibrium constant, and effective ionic capacity of the mAb variants in these gradient elution systems. Comparison of the 2D plots indicated that the advantage of opposite dual salt-pH gradient system with increasing pH gradient and simultaneously decreasing salt gradient is the noncontinuous increased acceleration of protein migration. Furthermore, the fitted model parameters can be used for the prediction and optimization of mAb variants separation in dual salt-pH gradient and step elution. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 2018. © 2018 American Institute of Chemical Engineers.

  19. Dual-porosity modeling of groundwater recharge: testing a quick calibration using in situ moisture measurements, Areuse River Delta, Switzerland

    Science.gov (United States)

    Alaoui, Abdallah; Eugster, Werner

    A simple method for calibrating the dual-porosity MACRO model via in situ TDR measurements during a brief infiltration run (2.8 h) is proposed with the aim of estimating local groundwater recharge (GR). The recharge was modeled firstly by considering the entire 3 m of unsaturated soil, and secondly by considering only the topsoil to the zero-flux plane (0-0.70 m). The modeled recharge was compared against the GR obtained from field measurements. Measured GR was 313 mm during a 1-year period (15 October 1990-15 October 1991). The best simulation results were obtained when considering the entire unsaturated soil under equilibrium conditions excluding the macropore flow effect (330 mm), whereas under non-equilibrium conditions GR was overestimated (378 mm). Sensitivity analyses showed that the investigation of the topsoil is sufficient in estimating local GR in this case, since the water stored below this depth appears to be below the typical rooting depth of the vegetation and is not available for evapotranspiration. The modeled recharge under equilibrium conditions for the 0.7-m-topsoil layer was found to be 364 mm, which is in acceptable agreement with measurements. Une méthode simple pour la calibration du modèle à double porosité MACRO par des mesures TDR in situ durant un bref essai d'infiltration (2.8 h) a été proposée pour l'estimation locale de la recharge de la nappe (RN). La RN a été d'abord simulée en tenant compte de toute la zone non saturée (3 m) et ensuite, en considérant uniquement la couverture du sol entre zéro et le plan du flux nul (0.70 m). La RN simulée a été comparée à la RN observée. La RN mesurée durant une année (15 octobre 1990-15 octobre 1991) était de 313 mm. Les meilleures simulations ont été obtenues en tenant compte de toute la zone non saturée sous les conditions d'équilibre excluant le flux préférentiel (330 mm). Sous les conditions de non équilibre, la RN a été surestimée (378 mm). Les analyses de

  20. A Dual Processing Approach to Stereotype Change.

    Science.gov (United States)

    Johnston, Lucy; Coolen, Petra

    1995-01-01

    Considered stereotype change within a framework of dual process models. Using three experiments, manipulated task involvement, source credibility, and message quality. Findings proved dual process as appropriate when considering the processing of stereotype-disconfirming information and processing's impact on existing stereotypes. Different…

  1. Uncovering the structures of modular polyketide synthases.

    Science.gov (United States)

    Weissman, Kira J

    2015-03-01

    The modular polyketide synthases (PKSs) are multienzyme proteins responsible for the assembly of diverse secondary metabolites of high economic and therapeutic importance. These molecular 'assembly lines' consist of repeated functional units called 'modules' organized into gigantic polypeptides. For several decades, concerted efforts have been made to understand in detail the structure and function of PKSs in order to facilitate genetic engineering of the systems towards the production of polyketide analogues for evaluation as drug leads. Despite this intense activity, it has not yet been possible to solve the crystal structure of a single module, let alone a multimodular subunit. Nonetheless, on the basis of analysis of the structures of modular fragments and the study of the related multienzyme of animal fatty acid synthase (FAS), several models of modular PKS architecture have been proposed. This year, however, the situation has changed - three modular structures have been characterized, not by X-ray crystallography, but by the complementary methods of single-particle cryo-electron microscopy and small-angle X-ray scattering. This review aims to compare the cryo-EM structures and SAXS-derived structural models, and to interpret them in the context of previously obtained data and existing architectural proposals. The consequences for genetic engineering of the systems will also be discussed, as well as unresolved questions and future directions.

  2. Uncovering deformation processes from surface displacements

    Science.gov (United States)

    Stramondo, Salvatore

    2013-04-01

    geophysical data, such as teleseismic waveforms, strong motion records and GPS, have also been used by geophysicists for improved rupture models. Many models use equations for a uniform elastic half space stemming from the Okada formulation, but improved data constraints and the use of increasingly sophisticated modeling and inverse methods allowed for the exploration of models with variation of elastic properties in layers or more complex representation of fault and lithosphere structure and rheology. In volcanic studies the role of GPS and InSAR lies in the measurement of pre-eruptive inflation, co-eruptive deflation and the post-eruptive response. The spatio-temporal evolution of volcanic processes, the "breathing" of a volcano, can be monitored with temporal series of InSAR interferograms using multitemporal InSAR techniques. The measured deformation can be used as constraints for the formulation of the inverse problem, to retrieve information concerning the depth, size, shape of the magma chamber (and pressure change) and magma supply dynamics. Deformation modeling commonly relies on simple point sources, dikes and sills; or more complex volume-change sources to produce the different surface deformation patterns caused by magma intrusion.

  3. Weaving Social Foundations through Dance Pedagogy: A Pedagogy of Uncovering

    Science.gov (United States)

    Barr, Sherrie; Risner, Doug

    2014-01-01

    Today's dance educators enter classrooms populated by increasingly diverse students in which teachers' pedagogical knowledge necessitates heightened understandings of race, ethnicity, social class, gender, and sexuality. Uncovering taken-for-granted assumptions, dominant stereotypes, and educational structures that reproduce social…

  4. Analytical filtration model for nonlinear viscoplastic oil in the theory of oil production stimulation and heating of oil reservoir in a dual-well system

    Science.gov (United States)

    Ivanovich Astafev, Vladimir; Igorevich Gubanov, Sergey; Alexandrovna Olkhovskaya, Valeria; Mikhailovna Sylantyeva, Anastasia; Mikhailovich Zinovyev, Alexey

    2018-02-01

    Production of high-viscosity oil and design of field development systems for such oil is one of the most promising directions in the development of world oil industry. The ability of high-viscosity oil to show in filtration process properties typical for non-Newtonian systems is proven by experimental studies. Nonlinear relationship between the pressure gradient and the rate of oil flow is due to interaction of high-molecular substances, in particular, asphaltenes and tars that form a plastic structure in it. The authors of this article have used the analytical model of stationary influx of nonlinear viscoplastic oil to the well bottom in order to provide rationale for the intensifying impact on a reservoir. They also have analyzed the method of periodic heating of productive reservoir by means of dual-wells. The high-temperature source is placed at the bottom of the vertical well, very close to the reservoir; at the same time the side well, located outside the zone of expected rock damage, is used for production. Suggested method of systemic treatment of reservoirs with dual wells can be useful for small fields of high-viscosity oil. The effect is based on the opportunity to control the structural and mechanical properties of high-viscosity oil and to increase depletion of reserves.

  5. Uncovering randomness and success in society.

    Directory of Open Access Journals (Sweden)

    Sarika Jalan

    Full Text Available An understanding of how individuals shape and impact the evolution of society is vastly limited due to the unavailability of large-scale reliable datasets that can simultaneously capture information regarding individual movements and social interactions. We believe that the popular Indian film industry, "Bollywood", can provide a social network apt for such a study. Bollywood provides massive amounts of real, unbiased data that spans more than 100 years, and hence this network has been used as a model for the present paper. The nodes which maintain a moderate degree or widely cooperate with the other nodes of the network tend to be more fit (measured as the success of the node in the industry in comparison to the other nodes. The analysis carried forth in the current work, using a conjoined framework of complex network theory and random matrix theory, aims to quantify the elements that determine the fitness of an individual node and the factors that contribute to the robustness of a network. The authors of this paper believe that the method of study used in the current paper can be extended to study various other industries and organizations.

  6. Uncovering archaeological landscapes at Angkor using lidar.

    Science.gov (United States)

    Evans, Damian H; Fletcher, Roland J; Pottier, Christophe; Chevance, Jean-Baptiste; Soutif, Dominique; Tan, Boun Suy; Im, Sokrithy; Ea, Darith; Tin, Tina; Kim, Samnang; Cromarty, Christopher; De Greef, Stéphane; Hanus, Kasper; Bâty, Pierre; Kuszinger, Robert; Shimoda, Ichita; Boornazian, Glenn

    2013-07-30

    Previous archaeological mapping work on the successive medieval capitals of the Khmer Empire located at Angkor, in northwest Cambodia (∼9th to 15th centuries in the Common Era, C.E.), has identified it as the largest settlement complex of the preindustrial world, and yet crucial areas have remained unmapped, in particular the ceremonial centers and their surroundings, where dense forest obscures the traces of the civilization that typically remain in evidence in surface topography. Here we describe the use of airborne laser scanning (lidar) technology to create high-precision digital elevation models of the ground surface beneath the vegetation cover. We identify an entire, previously undocumented, formally planned urban landscape into which the major temples such as Angkor Wat were integrated. Beyond these newly identified urban landscapes, the lidar data reveal anthropogenic changes to the landscape on a vast scale and lend further weight to an emerging consensus that infrastructural complexity, unsustainable modes of subsistence, and climate variation were crucial factors in the decline of the classical Khmer civilization.

  7. Uncovering the popularity mechanisms for Facebook applications

    Science.gov (United States)

    Li, Sheng-Nan; Guo, Qiang; Yang, Kai; Liu, Jian-Guo; Zhang, Yi-Cheng

    2018-03-01

    Understanding the popularity dynamics of online application(App) is significant for the online social systems. In this paper, by dividing the Facebook Apps into different groups in terms of their popularities, we empirically investigate the popularity dynamics for different kinds of Facebook Apps. Then, taking into account the influence of cumulative and recent popularities on the user choice, we present a model to regenerate the growth of popularity for different App groups. The experimental results of 917 Facebook Apps show that as the popularities of Facebook Apps increase, the recent popularity plays more important role. Specifically, the recent popularity plays more important role in regenerating the popularity dynamics for more popular Apps, and the cumulative popularity plays more important role for unpopular Apps. We also conduct temporal analysis on the growth characteristic of individual App by comparing the increment at each time with the average of historical records. The results show that the growth of more popular App tends to fluctuate more greatly. Our work may shed some lights for deeply understanding the popularity mechanism for online applications.

  8. Skin tumors Rb(eing uncovered

    Directory of Open Access Journals (Sweden)

    CLOTILDE eCOSTA

    2013-12-01

    Full Text Available The Rb1 gene was the first bona fide tumor suppressor identified and cloned more than 25 years ago. Since then, a plethora of studies have revealed the functions of pRb and the existence of a sophisticated and strictly regulated pathway that modulates such functional roles. An emerging paradox affecting Rb1 in cancer connects the relatively low number of mutations affecting Rb1 gene in specific human tumors, compared with the widely functional inactivation of pRb in most, if not in all, human cancers. The existence of a retinoblastoma family of proteins pRb, p107 and p130 and their potential unique and overlapping functions as master regulators of cell cycle progression and transcriptional modulation by similar processes, may provide potential clues to explain such conundrum. Here, we will review the development of different genetically engineered mouse models, in particular those affecting stratified epithelia, and how they have offered new avenues to understand the roles of the Rb family members and their targets in the context of tumor development and progression.

  9. Dual Diagnosis - Multiple Languages

    Science.gov (United States)

    ... Are Here: Home → Multiple Languages → All Health Topics → Dual Diagnosis URL of this page: https://medlineplus.gov/ ... V W XYZ List of All Topics All Dual Diagnosis - Multiple Languages To use the sharing features ...

  10. Uncovering ecodesign dilemmas : A path to business model innovation

    NARCIS (Netherlands)

    Prendeville, S.M.; O'Connor, Frank; Bocken, N.M.P.; Bakker, C.A.

    2017-01-01

    The aim of this article is to explore how ecodesign dilemmas contribute to a firm's ecodesign evolution. The article achieves this through empirical research into a process of ecodesign decision-making in a single firm. The study spans a timeframe of nine years. The article describes how recognising

  11. DUAL TIMELIKE NORMAL AND DUAL TIMELIKE SPHERICAL CURVES IN DUAL MINKOWSKI SPACE

    OpenAIRE

    ÖNDER, Mehmet

    2009-01-01

    Abstract: In this paper, we give characterizations of dual timelike normal and dual timelike spherical curves in the dual Minkowski 3-space and we show that every dual timelike normal curve is also a dual timelike spherical curve. Keywords: Normal curves, Dual Minkowski 3-Space, Dual Timelike curves. Mathematics Subject Classifications (2000): 53C50, 53C40. DUAL MINKOWSKI UZAYINDA DUAL TIMELIKE NORMAL VE DUAL TIMELIKE KÜRESEL EĞRİLER Özet: Bu çalışmada, dual Minkowski 3-...

  12. Dual Inflation

    CERN Document Server

    García-Bellido, J

    1998-01-01

    We propose a new model of inflation based on the soft-breaking of N=2 supersymmetric SU(2) Yang-Mills theory. The advantage of such a model is the fact that we can write an exact expression for the effective scalar potential, including non-perturbative effects, which preserves the analyticity and duality properties of the Seiberg-Witten solution. We find that the scalar condensate that plays the role of the inflaton can drive a long period of cosmological expansion, produce the right amount of temperature anisotropies in the microwave background, and end inflation when the monopole acquires a vacuum expectation value. Duality properties relate the weak coupling Higgs region where inflation takes place with the strong coupling monopole region, where reheating occurs, creating particles corresponding to the light degrees of freedom in the true vacuum.

  13. A novel dual GLP-1/GIP receptor agonist alleviates cognitive decline by re-sensitizing insulin signaling in the Alzheimer icv. STZ rat model.

    Science.gov (United States)

    Shi, Lijuan; Zhang, Zhihua; Li, Lin; Hölscher, Christian

    2017-06-01

    Alzheimer's disease (AD) is a progressive neurodegenerative disorder, accompanied by memory loss and cognitive impairments, and there is no effective treatment for it at present. Since type 2 diabetes (T2DM) has been identified as a risk factor for AD, the incretins glucagon-like peptide 1 (GLP-1) and glucose dependent insulinotropic polypeptide (GIP), promising antidiabetic agents for the treatment of type 2 diabetes, have been tested in models of neurodegenerative disease including AD and achieved good results. Here we show for the first time the potential neuroprotective effect of a novel dual GLP-1/GIP receptor agonist (DA-JC4) in the icv. streptozotocin (STZ)-induced AD rat model. Treatment with DA-JC4 (10nmol/kg ip.) once-daily for 14days after STZ intracerebroventricular (ICV) administration significantly prevented spatial learning deficits in a Y- maze test and Morris water maze tests, and decreased phosphorylated tau levels in the rat cerebral cortex and hippocampus. DA-JC4 also alleviated the chronic inflammation response in the brain (GFAP-positive astrocytes, IBA1-positive microglia). Apoptosis was reduced as shown in the reduced ratio of pro-apoptotic BAX to anti- apoptotic Bcl-2 levels. Importantly, insulin signaling was re-sensitized as evidenced by a reduction of phospho-IRS1 Ser1101 levels and phospho-Akt Ser473 up-regulation. In conclusion, the novel dual agonist DA-JC4 shows promise as a novel treatment for sporadic AD, and reactivating insulin signaling pathways may be a key mechanism that prevents disease progression in AD. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Impact of model complexity and multi-scale data integration on the estimation of hydrogeological parameters in a dual-porosity aquifer

    Science.gov (United States)

    Tamayo-Mas, Elena; Bianchi, Marco; Mansour, Majdi

    2018-03-01

    This study investigates the impact of model complexity and multi-scale prior hydrogeological data on the interpretation of pumping test data in a dual-porosity aquifer (the Chalk aquifer in England, UK). In order to characterize the hydrogeological properties, different approaches ranging from a traditional analytical solution (Theis approach) to more sophisticated numerical models with automatically calibrated input parameters are applied. Comparisons of results from the different approaches show that neither traditional analytical solutions nor a numerical model assuming a homogenous and isotropic aquifer can adequately explain the observed drawdowns. A better reproduction of the observed drawdowns in all seven monitoring locations is instead achieved when medium and local-scale prior information about the vertical hydraulic conductivity (K) distribution is used to constrain the model calibration process. In particular, the integration of medium-scale vertical K variations based on flowmeter measurements lead to an improvement in the goodness-of-fit of the simulated drawdowns of about 30%. Further improvements (up to 70%) were observed when a simple upscaling approach was used to integrate small-scale K data to constrain the automatic calibration process of the numerical model. Although the analysis focuses on a specific case study, these results provide insights about the representativeness of the estimates of hydrogeological properties based on different interpretations of pumping test data, and promote the integration of multi-scale data for the characterization of heterogeneous aquifers in complex hydrogeological settings.

  15. The Effect of Social and Cultural Factors on Ageism: Examination of the Dual-Process Motivational Model of Ideology, Politics, and Prejudice.

    Science.gov (United States)

    Doron, Israel; Kafka, Hanna

    2015-01-01

    This study seeks to examine the applicability of the Dual-Process Model of Ideology, Politics, and Prejudice (DPM) as a theoretical explanatory frame-work to ageism. The study is based on a secondary analysis of the European Social Survey (ESS), a quantitative project established in 2001 that includes 34 European countries. The sample was a representative random sample of the adult population of eight participating countries, and included a total of 19,073 participants. In general, this study's findings point to the fact that no statistically significant correlation exists between the personality variables, whether authoritative or social dominant, and ageism. It appears that the theoretical framework of the DPM model may not be appropriate as a theoretical and explanatory model of the phenomenon of ageism. This may indicate that ageism possibly differs from similar social phenomena, such as sexism and racism, at least in its DPM model basis. More research is needed in this field to better understand the applicability of the DPM model to ageism.

  16. A dual and opposite effect of Calendula officinalis flower extract: chemoprotector and promoter in a rat hepatocarcinogenesis model.

    Science.gov (United States)

    Barajas-Farias, L M; Pérez-Carreón, J I; Arce-Popoca, E; Fattel-Fazenda, S; Alemán-Lazarini, L; Hernández-García, S; Salcido-Neyoy, M; Cruz-Jiménez, F G; Camacho, J; Villa-Treviño, S

    2006-02-01

    Calendula officinalis extracts have protective and cytotoxic effects. We previously reported the dual activity of C. officinalis in primary rat hepatocyte cultures treated with N-nitrosodiethylamine. At nM concentrations it was anti-genotoxic while at microM concentrations it exhibited genotoxic effects. Here we tested the activity of Calendula officinalis in vivo in male Fischer 344 rats initiated with N-nitrosodiethylamine, promoted with 2-acetylaminofluorene, and 70 % partially hepatectomized. Liver gamma-glutamyltranspeptidase positively altered hepatocyte foci 25 days after initiation were our end point. The protective effect of C. officinalis started at 0.1 mg/kg concentration, increased at 0.5 mg/kg and reached its maximum at 2.5 mg/kg, when it decreased the area and number of altered foci by 55 % and 49 %, respectively, in comparison with rats treated only with carcinogen. At 5 mg/kg the number and area of altered hepatocyte foci were still lower, but almost reached the figures of carcinogen-treated rats. Ten and 20 mg/kg doses produced a notorious increment in the area and number of altered hepatic foci, and at 40 mg/kg of extract the increment was 40 % and 53 %, respectively. Additionally, when 2-acetylaminofluorene was substituted by a 40 mg/kg C. officinalis extract, a promoting effect was observed with increments of 175 % and 266 % in area and number of altered hepatocyte foci with respect to controls. When N-nitrosodiethylamine was substituted by 40 mg/kg of extract, the latter did not show initiator activity. In summary, we showed a protecting activity of C. officinalis at low doses, but doses above 10 mg/kg increased altered hepatocyte foci. This dual effect is an example of the phenomenon of hormesis. Furthermore, 40 mg/kg of dry weight extract administered instead of 2-acetylaminofluorene induced a clear promoting activity. These in vivo results are similar and consistent with those reported by us in primary rat liver cell cultures.

  17. Uncovering introductory astronomy students' conceptual modules of lunar phases

    Science.gov (United States)

    Lindell, Rebecca; Traxler, Adrienne

    2017-01-01

    Brewe, Bruun and Bearden developed Module Analysis of Multiple Choice Responses (MAMCR) methodology for using network analysis to uncover the underlying conceptual modules of student performance on multiple-choice assessments. The Lunar Phases Concept Inventory (LPCI) assesses students understanding of lunar phases across 8 separate dimensions of understanding based on the results of a detailed qualitative phenomenology of college students' understanding of lunar phases. Unlike many concept inventories, the LPCI has multiple items for each dimension of understanding and each response corresponds to either the scientifically correct answer or to an alternative idea uncovered from the qualitative investigation. In this study, we have combined MAMCR with the database of nearly 2000 LPCI pre-test results. We will report on the preliminary different conceptual modules of lunar phases and the relationship of these modules to previous qualitative research.

  18. Anxiety and categorisation effects in student nurses' attitudes towards young and older patients: A dual pathway model.

    Science.gov (United States)

    van Leeuwen, Esther; Oosterhuis, Misha; Ruyter, Sofie

    2016-04-01

    Student nurses often have a negative attitude towards older patients due to negative stereotypes, which may explain their reluctance to work in geriatric care. The aim of this study was to investigate a dual effect (direct and indirect via anxiety) of patients' age on student nurses' attitudes towards their patients. Quantitative survey study with 2 between-subjects conditions (patient age: young patients vs. older patients; both n's=52). Two schools for higher vocational education in the Netherlands. 104 student nurses between the ages of 16-30 in the third or fourth year of their nursing education (Mage=21.58, SD=2.22; 93 women). Attitudes towards older patients were more negative than those towards young patients. Older patients also elicited less anxiety compared to young patients, and anxiety had a weaker relationship with attitudes towards older patients than attitudes towards younger patients. Attitudes towards younger patients, but not towards older patients, were depressed by anxiety. Older patients generate more negative attitudes among student nurses, but can also improve attitudes indirectly by lowering intergroup anxiety. Older people may be therefore be especially suitable as a patient group to receive care from young nurses in training, who can mature in their profession without being anxious over making a wrong impression. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Uncovering Student Ideas in Astronomy 45 Formative Assessment Probes

    CERN Document Server

    Keeley, Page

    2012-01-01

    What do your students know-or think they know-about what causes night and day, why days are shorter in winter, and how to tell a planet from a star? Find out with this book on astronomy, the latest in NSTA's popular Uncovering Student Ideas in Science series. The 45 astronomy probes provide situations that will pique your students' interest while helping you understand how your students think about key ideas related to the universe and how it operates.

  20. Consolidity: Mystery of inner property of systems uncovered

    OpenAIRE

    Hassen T. Dorrah

    2012-01-01

    This paper uncovers the mystery of consolidity, an inner property of systems that was amazingly hidden. Consolidity also reveals the secrecy of why strong stable and highly controllable systems are not invulnerable of falling and collapsing. Consolidity is measured by its Consolidity Index, defined as the ratio of overall changes of output parameters over combined changes of input and system parameters, all operating in fully fuzzy environment. Under this notion, systems are classified into c...

  1. Analysis of Operation Parameters in a Dual Fluidized Bed Biomass Gasifier Integrated with a Biomass Rotary Dryer: Development and Application of a System Model

    Directory of Open Access Journals (Sweden)

    Nargess Puadian

    2014-07-01

    Full Text Available An integrated system model was developed in UniSim Design for a dual fluidized bed (DFB biomass gasifier and a rotary biomass dryer using a combination of user-defined and built-in unit operations. A quasi-equilibrium model was used for modelling biomass steam gasification in the DFB gasifier. The biomass drying was simulated with consideration of mass and energy balances, heat transfer, and dryer’s configuration. After validation using experimental data, the developed system model was applied to investigate: (1 the effects of gasification temperature and steam to biomass (S/B ratio on the gasification performance; (2 the effect of air supplied to the fast fluidized bed (FFB reactor and feed biomass moisture content on the integrated system performance, energy and exergy efficiencies. It was found that gasification temperature and S/B ratio have positive effects on the gasification yields; a H2/CO ratio of 1.9 can be achieved at the gasification temperature of 850 °C with a S/B ratio of 1.2. Consumption of excessive fuel in the system at higher biomass feed moisture content can be compensated by the heat recovery such as steam generation while it has adverse impact on exergy efficiency of the system.

  2. Uncovering signal transduction networks from high-throughput data by integer linear programming.

    Science.gov (United States)

    Zhao, Xing-Ming; Wang, Rui-Sheng; Chen, Luonan; Aihara, Kazuyuki

    2008-05-01

    Signal transduction is an important process that transmits signals from the outside of a cell to the inside to mediate sophisticated biological responses. Effective computational models to unravel such a process by taking advantage of high-throughput genomic and proteomic data are needed to understand the essential mechanisms underlying the signaling pathways. In this article, we propose a novel method for uncovering signal transduction networks (STNs) by integrating protein interaction with gene expression data. Specifically, we formulate STN identification problem as an integer linear programming (ILP) model, which can be actually solved by a relaxed linear programming algorithm and is flexible for handling various prior information without any restriction on the network structures. The numerical results on yeast MAPK signaling pathways demonstrate that the proposed ILP model is able to uncover STNs or pathways in an efficient and accurate manner. In particular, the prediction results are found to be in high agreement with current biological knowledge and available information in literature. In addition, the proposed model is simple to be interpreted and easy to be implemented even for a large-scale system.

  3. Immunogenicity and therapeutic efficacy of a dual-component genetic cancer vaccine cotargeting carcinoembryonic antigen and HER2/neu in preclinical models.

    Science.gov (United States)

    Aurisicchio, Luigi; Peruzzi, Daniela; Koo, Gloria; Wei, Wei-Zen; La Monica, Nicola; Ciliberto, Gennaro

    2014-02-01

    Several cancer vaccine efforts have been directed to simultaneously cotarget multiple tumor antigens, with the intent to achieve broader immune responses and more effective control of cancer growth. Genetic cancer vaccines based on in vivo muscle electro-gene-transfer of plasmid DNA (DNA-EGT) and adenoviral vectors represent promising modalities to elicit powerful immune responses against tumor-associated antigens (TAAs) such as carcinoembryonic antigen (CEA) and human epidermal growth factor receptor-2 (HER2)/neu. Combinations of these modalities of immunization (heterologous prime-boost) can induce superior immune reactions as compared with single-modality vaccines. We have generated a dual component-dual target genetic cancer vaccine consisting of a DNA moiety containing equal amounts of two plasmids, one encoding the extracellular and transmembrane domains of HER2 (ECD.TM) and the other encoding CEA fused to the B subunit of Escherichia coli heat-labile toxin (LTB), and of an adenoviral subtype 6 dicistronic vector carrying the same two tumor antigens gene constructs. The CEA/HER2 vaccine was tested in two different CEA/HER2 double-transgenic mouse models and in NOD/scid-DR1 mice engrafted with the human immune system. The immune response was measured by enzyme-linked immunospot assay, flow cytometry, and ELISA. The CEA/HER2 vaccine was able to break immune tolerance against both antigens. Induction of a T cell and antibody immune response was detected in immune-tolerant mice. Most importantly, the vaccine was able to slow the growth of HER2/neu⁺ and CEA⁺ tumors. A significant T cell response was measured in NOD/scid-DR1 mice engrafted with human cord blood cells. In conclusion, the CEA/HER2 genetic vaccine was immunogenic and able to confer significant therapeutic effects. These data warrant the evaluation of this vaccination strategy in human clinical trials.

  4. Calibration model of a dual gain flat panel detector for 2D and 3D x-ray imaging

    International Nuclear Information System (INIS)

    Schmidgunst, C.; Ritter, D.; Lang, E.

    2007-01-01

    The continuing research and further development in flat panel detector technology have led to its integration into more and more medical x-ray systems for two-dimensional (2D) and three-dimensional (3D) imaging, such as fixed or mobile C arms. Besides the obvious advantages of flat panel detectors, like the slim design and the resulting optimum accessibility to the patient, their success is primarily a product of the image quality that can be achieved. The benefits in the physical and performance-related features as opposed to conventional image intensifier systems (e.g., distortion-free reproduction of imaging information or almost linear signal response over a large dynamic range) can be fully exploited, however, only if the raw detector images are correctly calibrated and postprocessed. Previous procedures for processing raw data contain idealizations that, in the real world, lead to artifacts or losses in image quality. Thus, for example, temperature dependencies or changes in beam geometry, as can occur with mobile C arm systems, have not been taken into account up to this time. Additionally, adverse characteristics such as image lag or aging effects have to be compensated to attain the best possible image quality. In this article a procedure is presented that takes into account the important dependencies of the individual pixel sensitivity of flat panel detectors used in 2D or 3D imaging and simultaneously minimizes the work required for an extensive recalibration. It is suitable for conventional detectors with only one gain mode as well as for the detectors specially developed for 3D imaging with dual gain read-out technology

  5. Virtual iron concentration imaging based on dual-energy CT for noninvasive quantification and grading of liver iron content: An iron overload rabbit model study

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Xian Fu; Yang, Yi; Xie, Xue Qian; Zhang, Huan; Chai, Wei Min; Yan, Fu Hua [Shanghai Jiao Tong University School of Medicine, Department of Radiology, Ruijin Hospital, Shanghai (China); Yan, Jing [Siemens Shanghai Medical Equipment Ltd., Shanghai (China); Wang, Li [Fudan University, Center of Analysis and Measurement, Shanghai (China); Schmidt, Bernhard [Siemens AG, Healthcare Sector, Forchheim (Germany)

    2015-09-15

    To assess the accuracy of liver iron content (LIC) quantification and grading ability associated with clinical LIC stratification using virtual iron concentration (VIC) imaging on dual-energy CT (DECT) in an iron overload rabbit model. Fifty-one rabbits were prepared as iron-loaded models by intravenous injection of iron dextran. DECT was performed at 80 and 140 kVp. VIC images were derived from an iron-specific algorithm. Postmortem LIC assessments were conducted on an inductively coupled plasma (ICP) spectrometer. Correlation between VIC and LIC was analyzed. VIC were stratified according to the corresponding clinical LIC thresholds of 1.8, 3.2, 7.0, and 15.0 mg Fe/g. Diagnostic performance of stratification was evaluated by receiver operating characteristic analysis. VIC linearly correlated with LIC (r = 0.977, P < 0.01). No significant difference was observed between VIC-derived LICs and ICP (P > 0.05). For the four clinical LIC thresholds, the corresponding cutoff values of VIC were 19.6, 25.3, 36.9, and 61.5 HU, respectively. The highest sensitivity (100 %) and specificity (100 %) were achieved at the threshold of 15.0 mg Fe/g. Virtual iron concentration imaging on DECT showed potential ability to accurately quantify and stratify hepatic iron accumulation in the iron overload rabbit model. (orig.)

  6. Evaluation of Lunar Prodigy dual-energy X-ray absorptiometry for assessing body composition in healthy persons and patients by comparison with the criterion 4-component model.

    Science.gov (United States)

    Williams, Jane E; Wells, Jonathan C K; Wilson, Catherine M; Haroun, Dalia; Lucas, Alan; Fewtrell, Mary S

    2006-05-01

    Dual-energy X-ray absorptiometry (DXA) is widely used to assess body composition in research and clinical practice. Several studies have evaluated its accuracy in healthy persons; however, little attention has been directed to the same issue in patients. The objective was to compare the accuracy of the Lunar Prodigy DXA for body-composition analysis with that of the reference 4-component (4C) model in healthy subjects and in patients with 1 of 3 disease states. A total of 215 subjects aged 5.0-21.3 y (n = 122 healthy nonobese subjects, n = 55 obese patients, n = 26 cystic fibrosis patients, and n = 12 patients with glycogen storage disease). Fat mass (FM), fat-free mass (FFM), and weight were measured by DXA and the 4C model. The accuracy of DXA-measured body-composition outcomes differed significantly between groups. Factors independently predicting bias in weight, FM, FFM, and percentage body fat in multivariate models included age, sex, size, and disease state. Biases in FFM were not mirrored by equivalent opposite biases in FM because of confounding biases in weight. The bias of DXA varies according to the sex, size, fatness, and disease state of the subjects, which indicates that DXA is unreliable for patient case-control studies and for longitudinal studies of persons who undergo significant changes in nutritional status between measurements. A single correction factor cannot adjust for inconsistent biases.

  7. To Resolve or Not To Resolve, that Is the Question: The Dual-Path Model of Incongruity Resolution and Absurd Verbal Humor by fMRI.

    Science.gov (United States)

    Dai, Ru H; Chen, Hsueh-Chih; Chan, Yu C; Wu, Ching-Lin; Li, Ping; Cho, Shu L; Hu, Jon-Fan

    2017-01-01

    It is well accepted that the humor comprehension processing involves incongruity detection and resolution and then induces a feeling of amusement. However, this three-stage model of humor processing does not apply to absurd humor (so-called nonsense humor). Absurd humor contains an unresolvable incongruity but can still induce a feeling of mirth. In this study, we used functional magnetic resonance imaging (fMRI) to identify the neural mechanisms of absurd humor. Specifically, we aimed to investigate the neural substrates associated with the complete resolution of incongruity resolution humor and partial resolution of absurd humor. Based on the fMRI data, we propose a dual-path model of incongruity resolution and absurd verbal humor. According to this model, the detection and resolution for the incongruity of incongruity resolution humor activate brain regions involved in the temporo-parietal lobe (TPJ) implicated in the integration of multiple information and precuneus, likely to be involved in the ability of perspective taking. The appreciation of incongruity resolution humor activates regions the posterior cingulate cortex (PCC), implicated in autobiographic or event memory retrieval, and parahippocampal gyrus (PHG), implying the funny feeling. By contrast, the partial resolution of absurd humor elicits greater activation in the fusiform gyrus which have been implicated in word processing, inferior frontal gyrus (IFG) for the process of incongruity resolution and superior temporal gyrus (STG) for the pragmatic awareness.

  8. Self-dual nonsupersymmetric Type II String Compactifications

    International Nuclear Information System (INIS)

    Kachru, Shamit; Silverstein, Eva

    1998-01-01

    It has recently been proposed that certain nonsupersymmetric type II orbifolds have vanishing perturbative contributions to the cosmological constant. We show that techniques of Sen and Vafa allow one to construct dual type II descriptions of these models (some of which have no weakly coupled heterotic dual). The dual type II models are given by the same orbifolds with the string coupling S and a T 2 volume T exchanged. This allows us to argue that in various strongly coupled limits of the original type II models, there are weakly coupled duals which exhibit the same perturbative cancellations as the original models

  9. Mechanism-based pharmacokinetic/pharmacodynamic modeling of rat prefrontal cortical dopamine response to dual acting norepinephrine reuptake inhibitor and 5-HT1A partial agonist.

    Science.gov (United States)

    Li, Cheryl Shuang-wu; Zhang, Liming; Haske, Taraneh; Dounay, Amy; Gray, David; Barta, Nancy; Brodfuehrer, Joanne; Lepsy, Christopher; Campbell, Brian

    2012-06-01

    Evidence suggests that compounds possessing both norepinephrine reuptake inhibition and 5-HT(1A) partial agonism (NRI/5-HT(1A)) activities may have a greater efficacy in treating neuropsychiatric disorders than compounds possessing either activity alone. The objectives of the present study were first to characterize the pharmacokinetic/pharmacodynamic (PK/PD) relationship of the plasma concentrations of atomoxetine (NRI) and buspirone (5-HT(1A) partial agonist), administered alone and in combination, on the prefrontal cortex dopamine levels in rats, and second to use the model developed to characterize the PK/PD relationship of novel NRI/5-HT(1A) compounds, PF-04269339 and PF-03529936, in a NRI/5-HT(1A) drug discovery program. Maximal dopamine elevation was twofold higher after administration of atomoxetine and buspirone in combination, PF-04269339, or PF-03529936 than after administration of atomoxetine or buspirone alone. A mechanism-based extended indirect response model characterized the time profiles of the prefrontal cortex dopamine response to atomoxetine and buspirone, administered alone or in combination. After fixing three mechanism-specific pharmacodynamic parameters (I (max) and γ2 for NRI and γ1 for 5-HT(1A)) based on the model for atomoxetine and/or buspirone, the model fitted the exposure-response profiles of PF-04269339 and PF-03529936 well. Good in vitro-to-in vivo correlation was demonstrated with the compound-specific pharmacodynamic parameters (IC(50) for NRI and SC(50) and S (max) for 5-HT(1A)) across the compounds. In summary, a piecewise modeling approach was used successfully for the characterization of the PK/PD relationship of novel NRI/5-HT(1A) compounds on prefrontal cortex dopamine levels in rats. The application and value of the mechanism-based modeling in the dual pharmacology drug discovery program are also discussed.

  10. Dual Income Taxes

    DEFF Research Database (Denmark)

    Sørensen, Peter Birch

    This paper discusses the principles and practices of dual income taxation in the Nordic countries. The first part of the paper explains the rationale and the historical background for the introduction of the dual income tax and describes the current Nordic tax practices. The second part...... of the paper focuses on the problems of taxing income from small businesses and the issue of corporate-personal tax integration under the dual income tax, considering alternative ways of dealing with these challenges. In the third and final part of the paper, I briefly discuss whether introducing a dual income...

  11. Dual-Doppler Feasibility Study

    Science.gov (United States)

    Huddleston, Lisa L.

    2012-01-01

    When two or more Doppler weather radar systems are monitoring the same region, the Doppler velocities can be combined to form a three-dimensional (3-D) wind vector field thus providing for a more intuitive analysis of the wind field. A real-time display of the 3-D winds can assist forecasters in predicting the onset of convection and severe weather. The data can also be used to initialize local numerical weather prediction models. Two operational Doppler Radar systems are in the vicinity of Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS); these systems are operated by the 45th Space Wing (45 SW) and the National Weather Service Melbourne, Fla. (NWS MLB). Dual-Doppler applications were considered by the 45 SW in choosing the site for the new radar. Accordingly, the 45th Weather Squadron (45 WS), NWS MLB and the National Aeronautics and Space Administration tasked the Applied Meteorology Unit (AMU) to investigate the feasibility of establishing dual-Doppler capability using the two existing systems. This study investigated technical, hardware, and software requirements necessary to enable the establishment of a dual-Doppler capability. Review of the available literature pertaining to the dual-Doppler technique and consultation with experts revealed that the physical locations and resulting beam crossing angles of the 45 SW and NWS MLB radars make them ideally suited for a dual-Doppler capability. The dual-Doppler equations were derived to facilitate complete understanding of dual-Doppler synthesis; to determine the technical information requirements; and to determine the components of wind velocity from the equation of continuity and radial velocity data collected by the two Doppler radars. Analysis confirmed the suitability of the existing systems to provide the desired capability. In addition, it is possible that both 45 SW radar data and Terminal Doppler Weather Radar data from Orlando International Airport could be used to alleviate any

  12. Dual quaternions and dual projective spaces

    Energy Technology Data Exchange (ETDEWEB)

    Ata, Erhan [Department of Mathematics, Dumlupinar University, 43100 Kutahya (Turkey)], E-mail: eata@dumlupinar.edu.tr; Yayli, Yusuf [Department of Mathematics, Ankara University, 06100 Ankara (Turkey)

    2009-05-15

    In this study, dual unitary matrices SU{sub D}(2) were obtained. We correspond to one to one elements of the unit dual sphere S{sub D}{sup 3} with the dual unitary matrices SU{sub D}(2). Thus, we express spherical concepts such as meridians of longitude and parallels of latitude on SU{sub D}(2). The equality SO(R{sup 3}) {approx_equal} S{sup 3}/{l_brace}{+-}1{r_brace} = RP{sup 3} known as the real projective spaces was generalized to the dual projective space and then, the equality SO(D{sup 3}){approx_equal}S{sub D}{sup 3}/{l_brace}{+-}1{r_brace}=DP{sup 3} was acquired. In particular, 2-sphere S{sup 2} was obtained by considering dual parts as zero of S{sub D}{sup 3}. Hence, it was found that Hop fibriation map of S{sup 2} can be used for Twistors in quantum mechanics applications.

  13. Benchmark Comparison of Dual- and Quad-Core Processor Linux Clusters with Two Global Climate Modeling Workloads

    Science.gov (United States)

    McGalliard, James

    2008-01-01

    This viewgraph presentation details the science and systems environments that NASA High End computing program serves. Included is a discussion of the workload that is involved in the processing for the Global Climate Modeling. The Goddard Earth Observing System Model, Version 5 (GEOS-5) is a system of models integrated using the Earth System Modeling Framework (ESMF). The GEOS-5 system was used for the Benchmark tests, and the results of the tests are shown and discussed. Tests were also run for the Cubed Sphere system, results for these test are also shown.

  14. Testing for the dual-route cascade reading model in the brain: an fMRI effective connectivity account of an efficient reading style.

    Science.gov (United States)

    Levy, Jonathan; Pernet, Cyril; Treserras, Sébastien; Boulanouar, Kader; Aubry, Florent; Démonet, Jean-François; Celsis, Pierre

    2009-08-18

    Neuropsychological data about the forms of acquired reading impairment provide a strong basis for the theoretical framework of the dual-route cascade (DRC) model which is predictive of reading performance. However, lesions are often extensive and heterogeneous, thus making it difficult to establish precise functional anatomical correlates. Here, we provide a connective neural account in the aim of accommodating the main principles of the DRC framework and to make predictions on reading skill. We located prominent reading areas using fMRI and applied structural equation modeling to pinpoint distinct neural pathways. Functionality of regions together with neural network dissociations between words and pseudowords corroborate the existing neuroanatomical view on the DRC and provide a novel outlook on the sub-regions involved. In a similar vein, congruent (or incongruent) reliance of pathways, that is reliance on the word (or pseudoword) pathway during word reading and on the pseudoword (or word) pathway during pseudoword reading predicted good (or poor) reading performance as assessed by out-of-magnet reading tests. Finally, inter-individual analysis unraveled an efficient reading style mirroring pathway reliance as a function of the fingerprint of the stimulus to be read, suggesting an optimal pattern of cerebral information trafficking which leads to high reading performance.

  15. Testing for the dual-route cascade reading model in the brain: an fMRI effective connectivity account of an efficient reading style.

    Directory of Open Access Journals (Sweden)

    Jonathan Levy

    Full Text Available Neuropsychological data about the forms of acquired reading impairment provide a strong basis for the theoretical framework of the dual-route cascade (DRC model which is predictive of reading performance. However, lesions are often extensive and heterogeneous, thus making it difficult to establish precise functional anatomical correlates. Here, we provide a connective neural account in the aim of accommodating the main principles of the DRC framework and to make predictions on reading skill. We located prominent reading areas using fMRI and applied structural equation modeling to pinpoint distinct neural pathways. Functionality of regions together with neural network dissociations between words and pseudowords corroborate the existing neuroanatomical view on the DRC and provide a novel outlook on the sub-regions involved. In a similar vein, congruent (or incongruent reliance of pathways, that is reliance on the word (or pseudoword pathway during word reading and on the pseudoword (or word pathway during pseudoword reading predicted good (or poor reading performance as assessed by out-of-magnet reading tests. Finally, inter-individual analysis unraveled an efficient reading style mirroring pathway reliance as a function of the fingerprint of the stimulus to be read, suggesting an optimal pattern of cerebral information trafficking which leads to high reading performance.

  16. Dual gravity and matter

    NARCIS (Netherlands)

    Bergshoeff, Eric A.; Roo, Mees de; Kerstan, Sven F.; Kleinschmidt, Axel; Riccioni, Fabio

    We consider the problem of finding a dual formulation of gravity in the presence of non-trivial matter couplings. In the absence of matter a dual graviton can be introduced only for linearised gravitational interactions. We show that the coupling of linearised gravity to matter poses obstructions to

  17. A Dual Egalitarian Solution

    NARCIS (Netherlands)

    Klijn, F.; Slikker, M.; Tijs, S.H.

    2000-01-01

    In this note we introduce an egalitarian solution, called the dual egalitarian solution, that is the natural counterpart of the egalitarian solution of Dutta and Ray (1989).We prove, among others, that for a convex game the egalitarian solution coincides with the dual egalitarian solution for its

  18. Dual Credit Report

    Science.gov (United States)

    Light, Noreen

    2016-01-01

    In 2015, legislation to improve access to dual-credit programs and to reduce disparities in access and completion--particularly for low income and underrepresented students--was enacted. The new law focused on expanding access to College in the High School but acknowledged issues in other dual-credit programs and reinforced the notion that cost…

  19. The Dual Career Family.

    Science.gov (United States)

    Gurtin, Lee

    1980-01-01

    The dual career couple is forced to make a series of choices and compromises that impact the realms of marriage and career. The dilemmas that confront dual career marriages can be overcome only by compromise, accommodation, and mutual understanding on the part of the individuals involved. A revamping of human resources and recruitment programs is…

  20. Co-firing straw with coal in a swirl-stabilized dual-feed burner: modelling and experimental validation

    DEFF Research Database (Denmark)

    Yin, Chungen; Kær, Søren Knudsen; Rosendahl, Lasse

    2010-01-01

    ) are independently fed into the burner through two concentric injection tubes, i.e., the centre and annular tubes, respectively. Multiple simulations are performed, using three meshes, two global reaction mechanisms for homogeneous combustion, two turbulent combustion models, and two models for fuel particle...... conversion. It is found that for pulverized biomass particles of a few hundred microns in diameter the intra-particle heat and mass transfer is a secondary issue at most in their conversion, and the global four-step mechanism of Jones and Lindstedt may be better used in modelling volatiles combustion....... The baseline CFD models show a good agreement with the measured maps of main species in the reactor. The straw particles, less affected by the swirling secondary air jet due to the large fuel/air jet momentum and large particle response time, travels in a nearly straight line and penetrate through the oxygen...

  1. Detection of motor imagery of swallow EEG signals based on the dual-tree complex wavelet transform and adaptive model selection

    Science.gov (United States)

    Yang, Huijuan; Guan, Cuntai; Sui Geok Chua, Karen; San Chok, See; Wang, Chuan Chu; Kok Soon, Phua; Tang, Christina Ka Yin; Keng Ang, Kai

    2014-06-01

    Objective. Detection of motor imagery of hand/arm has been extensively studied for stroke rehabilitation. This paper firstly investigates the detection of motor imagery of swallow (MI-SW) and motor imagery of tongue protrusion (MI-Ton) in an attempt to find a novel solution for post-stroke dysphagia rehabilitation. Detection of MI-SW from a simple yet relevant modality such as MI-Ton is then investigated, motivated by the similarity in activation patterns between tongue movements and swallowing and there being fewer movement artifacts in performing tongue movements compared to swallowing. Approach. Novel features were extracted based on the coefficients of the dual-tree complex wavelet transform to build multiple training models for detecting MI-SW. The session-to-session classification accuracy was boosted by adaptively selecting the training model to maximize the ratio of between-classes distances versus within-class distances, using features of training and evaluation data. Main results. Our proposed method yielded averaged cross-validation (CV) classification accuracies of 70.89% and 73.79% for MI-SW and MI-Ton for ten healthy subjects, which are significantly better than the results from existing methods. In addition, averaged CV accuracies of 66.40% and 70.24% for MI-SW and MI-Ton were obtained for one stroke patient, demonstrating the detectability of MI-SW and MI-Ton from the idle state. Furthermore, averaged session-to-session classification accuracies of 72.08% and 70% were achieved for ten healthy subjects and one stroke patient using the MI-Ton model. Significance. These results and the subjectwise strong correlations in classification accuracies between MI-SW and MI-Ton demonstrated the feasibility of detecting MI-SW from MI-Ton models.

  2. Organization of physical interactomes as uncovered by network schemas.

    Science.gov (United States)

    Banks, Eric; Nabieva, Elena; Chazelle, Bernard; Singh, Mona

    2008-10-01

    Large-scale protein-protein interaction networks provide new opportunities for understanding cellular organization and functioning. We introduce network schemas to elucidate shared mechanisms within interactomes. Network schemas specify descriptions of proteins and the topology of interactions among them. We develop algorithms for systematically uncovering recurring, over-represented schemas in physical interaction networks. We apply our methods to the S. cerevisiae interactome, focusing on schemas consisting of proteins described via sequence motifs and molecular function annotations and interacting with one another in one of four basic network topologies. We identify hundreds of recurring and over-represented network schemas of various complexity, and demonstrate via graph-theoretic representations how more complex schemas are organized in terms of their lower-order constituents. The uncovered schemas span a wide range of cellular activities, with many signaling and transport related higher-order schemas. We establish the functional importance of the schemas by showing that they correspond to functionally cohesive sets of proteins, are enriched in the frequency with which they have instances in the H. sapiens interactome, and are useful for predicting protein function. Our findings suggest that network schemas are a powerful paradigm for organizing, interrogating, and annotating cellular networks.

  3. Air Force Journal of Logistics. Development and Analysis of a Dual-Role Fighter Deployment Footprint Logistics Planning Model. Volume XXI, Number 1

    National Research Council Canada - National Science Library

    Griffis, Stanley

    1997-01-01

    .... The Joint Strike Fighter (JSF) is the next-generation, multi-service, multi-national dual-role fighter acquisition program focusing on the development, testing, and fielding of a replacement aircraft for aging air-to-ground...

  4. Functional test of pedotransfer functions to predict water flow and solute transport with the dual-permeability model MACRO

    Science.gov (United States)

    Moeys, J.; Larsbo, M.; Bergström, L.; Brown, C. D.; Coquet, Y.; Jarvis, N. J.

    2012-07-01

    Estimating pesticide leaching risks at the regional scale requires the ability to completely parameterise a pesticide fate model using only survey data, such as soil and land-use maps. Such parameterisations usually rely on a set of lookup tables and (pedo)transfer functions, relating elementary soil and site properties to model parameters. The aim of this paper is to describe and test a complete set of parameter estimation algorithms developed for the pesticide fate model MACRO, which accounts for preferential flow in soil macropores. We used tracer monitoring data from 16 lysimeter studies, carried out in three European countries, to evaluate the ability of MACRO and this "blind parameterisation" scheme to reproduce measured solute leaching at the base of each lysimeter. We focused on the prediction of early tracer breakthrough due to preferential flow, because this is critical for pesticide leaching. We then calibrated a selected number of parameters in order to assess to what extent the prediction of water and solute leaching could be improved. Our results show that water flow was generally reasonably well predicted (median model efficiency, ME, of 0.42). Although the general pattern of solute leaching was reproduced well by the model, the overall model efficiency was low (median ME = -0.26) due to errors in the timing and magnitude of some peaks. Preferential solute leaching at early pore volumes was also systematically underestimated. Nonetheless, the ranking of soils according to solute loads at early pore volumes was reasonably well estimated (concordance correlation coefficient, CCC, between 0.54 and 0.72). Moreover, we also found that ignoring macropore flow leads to a significant deterioration in the ability of the model to reproduce the observed leaching pattern, and especially the early breakthrough in some soils. Finally, the calibration procedure showed that improving the estimation of solute transport parameters is probably more important than the

  5. Functional test of pedotransfer functions to predict water flow and solute transport with the dual-permeability model MACRO

    Directory of Open Access Journals (Sweden)

    J. Moeys

    2012-07-01

    Full Text Available Estimating pesticide leaching risks at the regional scale requires the ability to completely parameterise a pesticide fate model using only survey data, such as soil and land-use maps. Such parameterisations usually rely on a set of lookup tables and (pedotransfer functions, relating elementary soil and site properties to model parameters. The aim of this paper is to describe and test a complete set of parameter estimation algorithms developed for the pesticide fate model MACRO, which accounts for preferential flow in soil macropores. We used tracer monitoring data from 16 lysimeter studies, carried out in three European countries, to evaluate the ability of MACRO and this "blind parameterisation" scheme to reproduce measured solute leaching at the base of each lysimeter. We focused on the prediction of early tracer breakthrough due to preferential flow, because this is critical for pesticide leaching. We then calibrated a selected number of parameters in order to assess to what extent the prediction of water and solute leaching could be improved.

    Our results show that water flow was generally reasonably well predicted (median model efficiency, ME, of 0.42. Although the general pattern of solute leaching was reproduced well by the model, the overall model efficiency was low (median ME = −0.26 due to errors in the timing and magnitude of some peaks. Preferential solute leaching at early pore volumes was also systematically underestimated. Nonetheless, the ranking of soils according to solute loads at early pore volumes was reasonably well estimated (concordance correlation coefficient, CCC, between 0.54 and 0.72. Moreover, we also found that ignoring macropore flow leads to a significant deterioration in the ability of the model to reproduce the observed leaching pattern, and especially the early breakthrough in some soils. Finally, the calibration procedure showed that improving the estimation of solute transport parameters is

  6. Pressure Transient Analysis of Dual Fractal Reservoir

    Directory of Open Access Journals (Sweden)

    Xiao-Hua Tan

    2013-01-01

    Full Text Available A dual fractal reservoir transient flow model was created by embedding a fracture system simulated by a tree-shaped fractal network into a matrix system simulated by fractal porous media. The dimensionless bottom hole pressure model was created using the Laplace transform and Stehfest numerical inversion methods. According to the model's solution, the bilogarithmic type curves of the dual fractal reservoirs are illustrated, and the influence of different fractal factors on pressure transient responses is discussed. This semianalytical model provides a practical and reliable method for empirical applications.

  7. Total Retinal Blood Flow in a Nonhuman Primate Optic Nerve Transection Model Using Dual-Beam Bidirectional Doppler FD-OCT and Microsphere Method.

    Science.gov (United States)

    Told, Reinhard; Wang, Lin; Cull, Grant; Thompson, Simon J; Burgoyne, Claude F; Aschinger, Gerold C; Schmetterer, Leopold; Werkmeister, René M

    2016-03-01

    We validated noninvasive Doppler-optical coherence tomography (OCT) blood flow measurements against the terminal microsphere method in a surgical induced optic nerve transection nonhuman primate model. In 6 nonhuman primates, total retinal blood flow (TRBF) was measured with a custom-built dual-beam bidirectional Doppler Fourier Domain (FD)-OCT. Peripapillary retinal nerve fiber layer thickness (RNFLT) was measured by Spectralis spectral-domain (SD)-OCT. Measurements were performed every 10 to 15 days before and after unilateral optic nerve transection (ONT) until RNFLT was reduced by more than 40% from baseline. Before the animals were killed, TRBF was measured using the microsphere technique. A significant correlation between all arterial and venous Doppler OCT TRBF measurements was found in ONT and contralateral control eyes (both P FD-OCT and the microsphere method. It also was possible to monitor changes over time in TRBF after ONT with Doppler OCT. These findings highlight the accuracy and potential of noninvasive Doppler OCT to provide valuable information for detecting early changes in ocular disease in future.

  8. Estimation of rice grain yield from dual-polarization Radarsat-2 SAR data by integrating a rice canopy scattering model and a genetic algorithm

    Science.gov (United States)

    Zhang, Yuan; Yang, Bin; Liu, Xiaohui; Wang, Cuizhen

    2017-05-01

    Fast and accurate estimation of rice yield plays a role in forecasting rice productivity for ensuring regional or national food security. Microwave synthetic aperture radar (SAR) data has been proved to have a great potential for rice monitoring and parameters retrieval. In this study, a rice canopy scattering model (RCSM) was revised and then was applied to simulate the backscatter of rice canopy. The combination of RCSM and genetic algorithm (GA) was proposed for retrieving two important rice parameters relating to grain yield, ear length and ear number density, from a C-band, dual-polarization (HH and HV) Radarsat-2 SAR data. The stability of retrieved results of GA inversion was also evaluated by changing various parameter configurations. Results show that RCSM can effectively simulate backscattering coefficients of rice canopy at HH and HV mode with an error of <1 dB. Reasonable selection of GA's parameters is essential for stability and efficiency of rice parameter retrieval. Two rice parameters are retrieved by the proposed RCSM-GA technology with better accuracy. The rice ear length are estimated with error of <1.5 cm, and ear number density with error of <23 #/m2. Rice grain yields are effectively estimated and mapped by the retrieved ear length and number density via a simple yield regression equation. This study further illustrates the capability of C-band Radarsat-2 SAR data on retrieval of rice ear parameters and the practicability of radar remote sensing technology for operational yield estimation.

  9. Beyond dual systems: A genetically-informed, latent factor model of behavioral and self-report measures related to adolescent risk-taking

    Directory of Open Access Journals (Sweden)

    K. Paige Harden

    2017-06-01

    Full Text Available The dual systems model posits that adolescent risk-taking results from an imbalance between a cognitive control system and an incentive processing system. Researchers interested in understanding the development of adolescent risk-taking use a diverse array of behavioral and self-report measures to index cognitive control and incentive processing. It is currently unclear whether different measures commonly interpreted as indicators of the same psychological construct do, in fact, tap the same underlying dimension of individual differences. In a diverse sample of 810 adolescent twins and triplets (M age = 15.9 years, SD = 1.4 years from the Texas Twin Project, we investigated the factor structure of fifteen self-report and task-based measures relevant to adolescent risk-taking. These measures can be organized into four factors, which we labeled premeditation, fearlessness, cognitive dyscontrol, and reward seeking. Most behavioral measures contained large amounts of task-specific variance; however, most genetic variance in each measure was shared with other measures of the corresponding factor. Behavior genetic analyses further indicated that genetic influences on cognitive dyscontrol overlapped nearly perfectly with genetic influences on IQ (rA = −0.91. These findings underscore the limitations of using single laboratory tasks in isolation, and indicate that the study of adolescent risk taking will benefit from applying multimethod approaches.

  10. Dual Effects of Bisphosphonates on Ectopic Skin and Vascular Soft Tissue Mineralization versus Bone Microarchitecture in a Mouse Model of Generalized Arterial Calcification of Infancy

    Science.gov (United States)

    Li, Qiaoli; Kingman, Joshua; Sundberg, John P.; Levine, Michael A.; Uitto, Jouni

    2015-01-01

    Generalized arterial calcification of infancy (GACI) is an intractable ectopic mineralization disorder caused by mutations in the ENPP1 gene resulting in reduced plasma inorganic pyrophosphate levels. We previously characterized the Enpp1asj mutant mouse as a model of GACI, and we have now explored the potential efficacy of bisphosphonates, non-hydrolyzable PPi analogs, in preventing ectopic mineralization in these mice. These mice were maintained on either basic diet (control) or diets containing etidronate or alendronate in three different concentrations (experimental). Considering low bioavailability of bisphosphonates when administered orally, subsequent studies tested the mice with subcutaneous injections of etidronate. The treatments were initiated at 4 weeks of age, and the degree of mineralization was assessed at 12 weeks of age by quantitation of calcium deposits in the muzzle skin containing dermal sheath of vibrissae and in aorta. We found that bisphosphonate treatments significantly reduced mineralization in skin and aorta. These changes in treated mice were accompanied with restoration of their bone microarchitecture, determined bymicrocomputed tomography. The inhibitory capacity of bisphosphonates, with mechanistic implications, was confirmed in a cell-based mineralization assay in vitro. Collectively, these results suggest that bisphosphonate treatment may be beneficial by a dual effect for preventing ectopic soft tissue mineralization while correcting decreased bone mineralization in GACI caused by ENPP1 mutations. PMID:26763447

  11. A Dual Step Transfer Model: Sport and Non-Sport Extracurricular Activities and the Enhancement of Academic Achievement

    Science.gov (United States)

    Bradley, John L.; Conway, Paul F.

    2016-01-01

    This paper explores the influence that school sport and non-sport extracurricular activities (ssEC and nsEC) can have on academic achievement. A central thesis of this paper is that, despite the literature on the perceived and presumed benefits of school sport and of non-sport activities, theorising a model of the process by which the benefit is…

  12. Hepatic insulin sensitivity in healthy and prediabetic subjects: from a dual- to a single-tracer oral minimal model.

    Science.gov (United States)

    Visentin, Roberto; Dalla Man, Chiara; Basu, Rita; Basu, Ananda; Rizza, Robert A; Cobelli, Claudio

    2015-07-15

    Recently, a model was proposed to assess hepatic insulin sensitivity during a meal, i.e., the ability of insulin to suppress glucose production (EGP), SI (P). The model was developed on EGP data obtained from a triple-tracer meal and the tracer-to-tracee clamp technique and validated against the euglycemic hyperinsulinemic clamp. The aim of this study was to assess whether SI (P) can be obtained from plasma concentrations measured after a single-tracer meal by incorporating the above EGP model into the oral glucose minimal model by describing both glucose production and disposal (OMM(PD)). Triple-tracer meal data of two databases (20 healthy and 60 healthy and prediabetic subjects) were used. Virtually model-independent EGP estimates were calculated. OMM(PD) was identified on exogenous and endogenous glucose concentrations, providing indices of SI (P), disposal insulin sensitivity (SI (D)), and EGP. The model fitted the data well, and SI (P) and SI (D) were estimated with precision in both databases (SI (P) = 5.48 ± 0.54 10(-4) dl·kg(-1)·min(-1) per μU/ml and SI (D) = 9.93 ± 2.18 10(-4) dl·kg(-1)·min(-1) per μU/ml in healthy; SI (P) = 5.41 ± 3.55 10(-4) dl·kg(-1)·min(-1) per μU/ml and SI (D) = 5.34 ± 6.17 10(-4) dl·kg(-1)·min(-1) per μU/ml, in healthy and prediabetic subjects). Estimated SI (P) and that derived from the triple-tracer EGP model were very similar on average. Moreover, the time course of EGP normalized to basal EGP (EGPb), and EGP/EGPb agreed with the results obtained using the triple-tracer method. In this study, we have demonstrated that SI (P), SI (D), and EGP/EGPb time course can be estimated reliably from a single-tracer meal protocol in both healthy and prediabetic subjects. Copyright © 2015 the American Physiological Society.

  13. Uncovering Sundanese Values by Analyzing Symbolic Meaning of Ménak Priangan Clothing (1800-1942)

    Science.gov (United States)

    Karmila, M.; Suciati; Widiaty, I.

    2016-04-01

    This study investigates symbolic meanings found in the Sunda ethnic clothing, particularly the Menak Priangan clothing. This study aims to uncover and document those symbolic meanings found in the Menak Priangan clothing as an effort to develop Sunda cultural artefacts of West Java. This study on Menak Priangan clothing applies ethnography (visual) and aesthetic methods. The visual method is utilized in order to uncover local cultural (Sunda) values found in Menak Priangan clothing visualization, including: design, model, name, and representing colours, which then directed towards local Sundanese aesthetic concepts living within the Priangan community. Furthermore, aesthetic method is used to explore role of aesthetic values in empowering visual cultural values within certain community, particularly Sunda aesthetic values. The study results show that since the 19th century, Sunda ethnic clothing was limited to Priangan Sunda only, while traditional clothing wearing by Priangan people reflects their social strata, consisting of: a. Menak Gede (Menak pangluhurna: mayor), bearing raden title, b. Menak Leutik/Santana (mayor assistant), titles: asep, mas, agus, ujang, (Nyimas for woman), c. Somah/Cacah: ordinary people/lower class. Clothing is a cultural phenomenon within certain culture reflecting such society experiences. For Menak people, clothing and its accessories have important meanings. They wear such traditional clothing and accessories as a symbol of power they have within bureaucratic structure and as a symbol of social status they bear within traditional community structure.

  14. Absorbing Markov Chain Models to Determine Optimum Process Target Levels in Production Systems with Dual Correlated Quality Characteristics

    Directory of Open Access Journals (Sweden)

    Mohammad Saber Fallah Nezhad

    2012-03-01

    Full Text Available For a manufacturing organization to compete effectively in the global marketplace, cutting costs and improving overall efficiency is essential.  A single-stage production system with two independent quality characteristics and different costs associated with each quality characteristic that falls below a lower specification limit (scrap or above an upper specification limit (rework is presented in this paper. The amount of reworks and scraps are assumed to be depending on the process parameters such as process mean and standard deviation thus the expected total profit is significantly dependent on the process parameters. This paper develops a Markovian decision making model for determining the process means. Sensitivity analyzes is performed to validate, and a numerical example is given to illustrate the proposed model. The results showed that the optimal process means extremely effects on the quality characteristics’ parameters.

  15. Simultaneous Pharmacokinetic Modeling of Alkylresorcinols and Their Main Metabolites Indicates Dual Absorption Mechanisms and Enterohepatic Elimination in Humans

    DEFF Research Database (Denmark)

    Marklund, Matti; Strömberg, Eric A,; Lærke, Helle Nygaard

    2014-01-01

    was to develop a combined pharmacokinetic model for plasma concentrations of alkylresorcinols and their 2 major metabolites, 3,5-dihydroxybenzoic acid (DHBA) and 3-(3,5-dihydroxyphenyl)-propanoic acid (DHPPA).Methods: The model was established by using plasma samples collected from 3 women and 2 men after...... a single dose (120 g) of rye bran and validated against fasting plasma concentrations from 8 women and 7 men with controlled rye bran intake (23, 45, or 90 g/d). Alkylresorcinols in the lymph and plasma of a pig fed a single alkylresorcinol dose (1.3 mmol) were quantified to assess absorption. Human......% of the alkylresorcinol dose was recovered in the lymph. DHPPA was identified in both human ileostomal effluent and pig bile, indicating availability of DHPPA for absorption and enterohepatic circulation.Conclusion: Intact alkylresorcinols have advantages over DHBA and DHPPA as plasma biomarkers for whole-grain wheat...

  16. A dual theory of price and value in a meso-scale economic model with stochastic profit rate

    Science.gov (United States)

    Greenblatt, R. E.

    2014-12-01

    The problem of commodity price determination in a market-based, capitalist economy has a long and contentious history. Neoclassical microeconomic theories are based typically on marginal utility assumptions, while classical macroeconomic theories tend to be value-based. In the current work, I study a simplified meso-scale model of a commodity capitalist economy. The production/exchange model is represented by a network whose nodes are firms, workers, capitalists, and markets, and whose directed edges represent physical or monetary flows. A pair of multivariate linear equations with stochastic input parameters represent physical (supply/demand) and monetary (income/expense) balance. The input parameters yield a non-degenerate profit rate distribution across firms. Labor time and price are found to be eigenvector solutions to the respective balance equations. A simple relation is derived relating the expected value of commodity price to commodity labor content. Results of Monte Carlo simulations are consistent with the stochastic price/labor content relation.

  17. Comparing Two Numerical Models in Simulating Hydrodynamics and Sediment Transport at a Dual Inlet System, West-Central Florida

    Science.gov (United States)

    2015-05-15

    Pass, the Willmott skill was 0.989 for CMS and 0.938 for DELFT3D. Qualitatively, as compared to flow field measurements using a ship- mounted ADCP , both...offshore, providing boundary conditions for the numerical models. Several methods were used to measure the flow field. An upward-looking ADCP was...deployed in the main channel of each inlet to measured current profiles. A side-looking ADCP was deployed at each inlet to measured cross-channel

  18. Uncovering dental implants using a new thermo-optically powered (TOP) technology with tissue air-cooling.

    Science.gov (United States)

    Romanos, Georgios E; Belikov, Andrey V; Skrypnik, Alexei V; Feldchtein, Felix I; Smirnov, Michael Z; Altshuler, Gregory B

    2015-07-01

    Uncovering implants with lasers, while bloodless, has been associated with a risk of implant and bone overheating. The present study evaluated the effect of using a new generation of high-power diode lasers on the temperature of a dental implant and the surrounding tissues using an in vitro model. The implant temperature was measured at three locations using micro thermocouples. Collateral thermal damage of uncovered soft tissues was evaluated using NTBC stain. Implant temperature rise during and collateral thermal soft-tissue damage following implant uncovering with and without tissue air-cooling was studied using both the classic operational mode and the new thermo-optically powered (TOP) technology. For the classic surgical mode using a cork-initiated tip and constant laser power set at 3.4 W, the maximum temperature rise in the coronal and apical parts of the implant was 23.2 ± 4.1°С and 9.5 ± 1.8°С, respectively, while 1.5 ± 0.5 mm of collateral thermal damage of the soft tissue surrounding the implant model occurred. Using the TOP surgical tip with constant laser power reduced implant overheating by 30%; collateral thermal soft-tissue damage was 0.8 ± 0.2 mm. Using the TOP surgical mode with a tip temperature setting of 800°C and air-cooling reduced the implant temperature rise by more than 300%, and only 0.2 ± 0.1 mm of collateral thermal soft-tissue damage occurred, typical for optimized CO2 laser surgery. Furthermore, use of the new generation diode technology (TOP surgical mode) appeared to reduce the time required for implant uncovering by a factor of two, compared to the standard surgical mode. Use of the new generation diode technology (TOP surgical mode) may significantly reduce overheating of dental implants during uncovering and seems to be safer for the adjacent soft and hard tissues. Use of such diode lasers with air-cooling can radically reduce the rise in implant temperatures (by more than three times

  19. Dual Credit/Dual Enrollment and Data Driven Policy Implementation

    Science.gov (United States)

    Lichtenberger, Eric; Witt, M. Allison; Blankenberger, Bob; Franklin, Doug

    2014-01-01

    The use of dual credit has been expanding rapidly. Dual credit is a college course taken by a high school student for which both college and high school credit is given. Previous studies provided limited quantitative evidence that dual credit/dual enrollment is directly connected to positive student outcomes. In this study, predictive statistics…

  20. Dual education and industrial cooperation in electrical engineering

    Science.gov (United States)

    Váradiné Szarka, A.

    2016-11-01

    Dual education in higher education is a new system in Hungary introduced by Mercedes Benz with cooperation of Kecskemet College. In the new system companies support certain number of students and provide them strong practical education in their field. Students applying successfully for dual education study together with non-dual students at the university, so they go through the same university courses as their non-dual colleagues, but while non-dual students’ academic year includes 2×14 weeks active semester and 2×6 weeks exam session, all over 40 weeks, dual students have 48 working weeks including study at the university and practicing at the company. The main question of the success which one is the most effective model to be applied. This paper summarises 2 models of dual education with their advantages and disadvantages and also it presents practical realization at the University of Debrecen with special attention to measurement and instrumentation. Dual education in BSc level electrical engineering course cooperates with 6 multinational companies of the region in four specialization. Dual education also has great impact to the modernisation of engineering education. Detailed study of dual education in field of instrumentation and measurement is provided in the paper.