Van Stee, Stephanie K; Yang, Qinghua
2017-10-30
This study applied the comprehensive model of information seeking (CMIS) to online cancer information and extended the model by incorporating an exogenous variable: interest in online health information exchange with health providers. A nationally representative sample from the Health Information National Trends Survey 4 Cycle 4 was analyzed to examine the extended CMIS in predicting online cancer information seeking. Findings from a structural equation model supported most of the hypotheses derived from the CMIS, as well as the extension of the model related to interest in online health information exchange. In particular, socioeconomic status, beliefs, and interest in online health information exchange predicted utility. Utility, in turn, predicted online cancer information seeking, as did information-carrier characteristics. An unexpected but important finding from the study was the significant, direct relationship between cancer worry and online cancer information seeking. Theoretical and practical implications are discussed.
Bornkessel, Ina; Schlesewsky, Matthias
2006-10-01
Real-time language comprehension is a principal cognitive ability and thereby relates to central properties of the human cognitive architecture. Yet how do the presumably universal cognitive and neural substrates of language processing relate to the astounding diversity of human languages (over 5,000)? The authors present a neurocognitive model of online comprehension, the extended argument dependency model (eADM), that accounts for cross-linguistic unity and diversity in the processing of core constituents (verbs and arguments). The eADM postulates that core constituent processing proceeds in three hierarchically organized phases: (1) constituent structure building without relational interpretation, (2) argument role assignment via a restricted set of cross-linguistically motivated information types (e.g., case, animacy), and (3) completion of argument interpretation using information from further domains (e.g., discourse context, plausibility). This basic architecture is assumed to be universal, with cross-linguistic variation deriving primarily from the information types applied in Phase 2 of comprehension. This conception can derive the appearance of similar neurophysiological and neuroanatomical processing correlates in seemingly disparate structures in different languages and, conversely, of cross-linguistic differences in the processing of similar sentence structures. Copyright 2006 APA.
Extending comprehensive models of the Earth's magnetic field with Ørsted and CHAMP data
Sabaka, Terence J.; Olsen, Nils; Purucker, Michael E.
2004-11-01
A new model of the quiet-time, near-Earth magnetic field has been derived using a comprehensive approach, which includes not only POGO and Magsat satellite data, but also data from the Ørsted and CHAMP satellites. The resulting model shows great improvement over its predecessors in terms of completeness of sources, time span and noise reduction in parameters. With its well separated fields and extended time domain of 1960 to mid-2002, the model is able to detect the known sequence of geomagnetic jerks within this frame and gives evidence for an event of interest around 1997. Because all sources are coestimated in a comprehensive approach, intriguing north-south features typically filtered out with other methods are being discovered in the lithospheric representation of the model, such as the S Atlantic spreading ridge and Andean subduction zone lineations. In addition, this lithospheric field exhibits significantly less noise than previous models as a result of improved data selection. The F-region currents, through which the satellites pass, are now treated as lying within meridional planes, as opposed to being purely radial. Results are consistent with those found previously for Magsat, but an analysis at Ørsted altitude shows exciting evidence that the meridional currents associated with the equatorial electrojet likely close beneath the satellite. Besides the model, a new analysis technique has been developed to infer the portion of a model parameter state resolved by a particular data subset. This has proven very useful in diagnosing the cause of peculiar artefacts in the Magsat vector data, which seem to suggest the presence of a small misalignment bias in the vector magnetometer.
Extending comprehensive models of the Earth's magnetic field with Orsted and CHAMP data
DEFF Research Database (Denmark)
Sabaka, T.J.; Olsen, Nils; Purucker, M.E.
2004-01-01
A new model of the quiet-time, near-Earth magnetic field has been derived using a comprehensive approach, which includes not only POGO and Magsat satellite data, but also data from the Orsted and CHAMP satellites. The resulting model shows great improvement over its predecessors in terms of compl......A new model of the quiet-time, near-Earth magnetic field has been derived using a comprehensive approach, which includes not only POGO and Magsat satellite data, but also data from the Orsted and CHAMP satellites. The resulting model shows great improvement over its predecessors in terms...
Bornkessel, Ina; Schlesewsky, Matthias
2006-01-01
Real-time language comprehension is a principal cognitive ability and thereby relates to central properties of the human cognitive architecture. Yet how do the presumably universal cognitive and neural substrates of language processing relate to the astounding diversity of human languages (over 5,000)? The authors present a neurocognitive model of…
Reading Comprehension, Extended Processing and Attention Dysfunction.
Cherkes-Julkowski, Miriam; Stolzenberg, Jonathan
This study investigated the role of executive function in children with attention deficit disorders (ADD) by comparing differences resulting when diagnostic measures of reading comprehension consisting of either short or long passages were used. Subjects (all in grades 1-12) were grouped as having an attention deficit disorder (ADD) and not taking…
Extending reference assembly models
DEFF Research Database (Denmark)
Church, Deanna M.; Schneider, Valerie A.; Steinberg, Karyn Meltz
2015-01-01
The human genome reference assembly is crucial for aligning and analyzing sequence data, and for genome annotation, among other roles. However, the models and analysis assumptions that underlie the current assembly need revising to fully represent human sequence diversity. Improved analysis tools...... and updated data reporting formats are also required....
Extended Fundamental Model of Resonance
Breiter, Sławomir
2003-03-01
Fundamental models are the simplest, one degree of freedom Hamiltonians that serve as a tool to understand the qualitative effects of various resonances. A new, extended fundamental model (EFM) is proposed in order to improve the classical, Andoyer type, second fundamental model (SFM). The EFM Hamiltonian differs from the SFM by the addition of a term with the third power of momentum; it depends on two free parameters. The new model is studied for the case of a first-order resonance, where up to five critical points can be present. Similarly, to the respective SFM, it admits only the saddle-node bifurcations of critical points, but its advantage lies in the capability of generating the separatrix bifurcations, known also as saddle connections. The reduction of parameters for the EFM has been performed in a way that allows the use of the model in the case of the so-called abnormal resonance.
Center for Extended Magnetohydrodynamics Modeling
Energy Technology Data Exchange (ETDEWEB)
Ramos, Jesus [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
2017-02-14
This researcher participated in the DOE-funded Center for Extended Magnetohydrodynamics Modeling (CEMM), a multi-institutional collaboration led by the Princeton Plasma Physics Laboratory with Dr. Stephen Jardin as the overall Principal Investigator. This project developed advanced simulation tools to study the non-linear macroscopic dynamics of magnetically confined plasmas. The collaborative effort focused on the development of two large numerical simulation codes, M3D-C1 and NIMROD, and their application to a wide variety of problems. Dr. Ramos was responsible for theoretical aspects of the project, deriving consistent sets of model equations applicable to weakly collisional plasmas and devising test problems for verification of the numerical codes. This activity was funded for twelve years.
Modeling survival data extending the cox model
Therneau, Terry M
2000-01-01
Extending the Cox Model is aimed at researchers, practitioners, and graduate students who have some exposure to traditional methods of survival analysis The emphasis is on semiparametric methods based on the proportional hazards model The inclusion of examples with SAS and S-PLUS code will make the book accessible to most working statisticians
A model of comprehensive unification
Reig, Mario; Valle, José W. F.; Vaquera-Araujo, C. A.; Wilczek, Frank
2017-11-01
Comprehensive - that is, gauge and family - unification using spinors has many attractive features, but it has been challenged to explain chirality. Here, by combining an orbifold construction with more traditional ideas, we address that difficulty. Our candidate model features three chiral families and leads to an acceptable result for quantitative unification of couplings. A potential target for accelerator and astronomical searches emerges.
The Comprehensive Counseling Center Model
Brunner, Jon; Wallace, David; Keyes, Lee N.; Polychronis, Paul D.
2017-01-01
The authors outline a four-factor model and philosophy for college mental health services that addresses the loss of comprehensiveness in some centers due to changes in organizational structure. Given research on demand for services and retention of those seen in centers, emphasis is placed in particular upon the value of consultation, outreach,…
A model of poetic comprehension
Energy Technology Data Exchange (ETDEWEB)
Haase, K. [MIT Media Lab., Cambridge, MA (United States)
1996-12-31
This article introduces an account of aesthetic comprehension and experience together with an implemented miniature which generates analogical interpretations from a semi-automatic parse of Wordsworth`s {open_quotes}Lines Written in Early Spring{close_quotes}. In our account, a poem serves as an analogy teaching machine by using formal structure to cue the formation of novel analogies. This account builds on an analogical model of comprehension previously applied to large corpora of newspaper summaries. In the miniature, an automatic grammatical and semantic analysis of the text is augmented with information about rhyme and rhythm. These formal cues allow the system to determine analogies which it would not otherwise consider. The article describes the comprehension framework, the annotated piece, and the matcher`s performance on the piece. It closes with a discussion of possible objections to aspects of the thesis or experiment and suggested directions for future work.
The Comprehensive Emergent Literacy Model
Directory of Open Access Journals (Sweden)
Leigh Rohde
2015-03-01
Full Text Available The early skills of Emergent Literacy include the knowledge and abilities related to the alphabet, phonological awareness, symbolic representation, and communication. However, existing models of emergent literacy focus on discrete skills and miss the perspective of the surrounding environment. Early literacy skills, including their relationship to one another, and the substantial impact of the setting and context, are critical in ensuring that children gain all of the preliminary skills and awareness they will need to become successful readers and writers. Research findings over the last few decades have led to a fuller understanding of all that emergent literacy includes, resulting in a need for a new, more comprehensive model. A new model, described in this article, strives to explain how emergent literacy can be viewed as an interactive process of skills and context rather than a linear series of individual components. Early literacy learning opportunities are more likely to happen when teachers have a solid knowledge base of emergent literacy and child development. Research has shown that preschool teachers with limited knowledge about literacy development are significantly less able to provide such experiences for children. Teachers will be better able to facilitate all of the components of emergent literacy if they have access to, and understanding of, a model that describes the components, their interactions, and the importance of environmental factors in supporting children.
Building Information Modeling Comprehensive Overview
Directory of Open Access Journals (Sweden)
Sergey Kalinichuk
2015-07-01
Full Text Available The article is addressed to provide a comprehensive review on recently accelerated development of the Information Technology within project market such as industrial, engineering, procurement and construction. Author’s aim is to cover the last decades of the growth of the Information and Communication Technology in construction industry in particular Building Information Modeling and testifies that the problem of a choice of the effective project realization method not only has not lost its urgency, but has also transformed into one of the major condition of the intensive technology development. All of it has created a great impulse on shortening the project duration and has led to the development of various schedule compression techniques what becomes a focus of modern construction.
Lens-focused transducer modeling using an extended KLM model.
Maréchal, Pierre; Levassort, Franck; Tran-Huu-Hue, Louis-Pascal; Lethiecq, Marc
2007-05-01
The goal of this work was to develop an extended ultrasound transducer model that would optimize the trade-off between accuracy of the calculation and computational time. The derivations are presented for a generalized transducer model, that is center frequency, pulse duration and physical dimensions are all normalized. The paper presents a computationally efficient model for lens-focused, circular (axisymmetric) single element piezoelectric ultrasound transducer. Specifically, the goal of the model is to determine the lens effect on the electro-acoustic response, both on focusing and on matching acoustic properties. The effective focal distance depends on the lens geometry and refraction index, but also on the near field limit, i.e. wavelength and source radius, and on the spectrum bandwidth of the ultrasound source. The broadband (80%) source generated by the transducer was therefore considered in this work. A new model based on a longitudinal-wave assumption is presented and the error introduced by this assumption is discussed in terms of its maximum value (16%) and mean value (5.9%). The simplified model was based on an extension of the classical KLM model for transducer structures and on the related assumptions. The validity of the implemented extended KLM model was evaluated by comparison with finite element modeling, itself previously validated analytically for the one-dimensional planar geometry considered. The pressure field was then propagated using the adequate formulation of the Rayleigh integral for both the extended KLM and finite element results. The simplified approach based on the KLM model delivered the focused response with good accuracy, and hundred-fold lower calculation time in comparison with a mode comprehensive FEM method. The trade-off between precision and time thus becomes compatible with an iterative procedure, used here for the optimization of the acoustic impedance of the lens for the chosen configuration. An experimental comparison
Robinson, Jack; Reed, William; Strauss, Richard
2011-01-01
This study sought to examine the impact of teachers' participation in an extended period of embedded professional development (PD) emphasizing teachers' use of assessment for learning practices (AFL) in extended problem based units of instruction within a comprehensive AFL framework. The extended and comprehensive approach of using both course…
Modeling extended lactations of dairy cows.
Vargas, B; Koops, W J; Herrero, M; Van Arendonk, J A
2000-06-01
Nine mathematical models were compared for their ability to predict daily milk yields (n = 294,986) in standard 305-d and extended lactations of dairy cows of Costa Rica. Lactations were classified by parity (first and later), lactation length (9 to 10, 11 to 12, 13 to 14, 15 to 16, and 16 to 17 mo), and calving to conception interval (1 to 2, 3 to 4, 5 to 6, 7 to 8, and 9 to 10 mo). Of the nine models, the diphasic model and lactation persistency model resulted in the best goodness of fit as measured by adjusted coefficient of determination, residual standard deviation, and Durbin-Watson coefficient. All other models showed less accuracy and positively correlated residuals. In extended lactations, models were also fitted using only test-day records before 305 d, which resulted in a different ranking. The diphasic model showed the best prediction of milk yield in standard and extended lactations. We concluded that the diphasic model provided accurate estimates of milk yield for standard and extended lactations. Interpretation of parameters deserves further attention because of the large variation observed. As expected, the calving to conception interval was found to have a negative effect on milk yield for cows with a standard lactation length. In extended lactations, these negative effects of pregnancy on milk yield were not observed.
Modeling the Extended Warranty: A Managerial Focus
Myung, Noah; Eger, Robert J.
2015-01-01
We provide a model of an extended warranty. To maximize profit, a producer always wants to sell with some type of warranty as opposed to selling with no warranty. The extended warranty is more likely to be provided as the consumer becomes more patient, as the producer becomes impatient, or if the likelihood of product failure does not increase too much in the extended period. We show that there is a separating equilibrium in which the high quality producers sell with warranties and the low qu...
Remarkable connections between extended magnetohydrodynamics models
Energy Technology Data Exchange (ETDEWEB)
Lingam, M., E-mail: manasvi@physics.utexas.edu; Morrison, P. J., E-mail: morrison@physics.utexas.edu; Miloshevich, G., E-mail: gmilosh@physics.utexas.edu [Department of Physics and Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712 (United States)
2015-07-15
Through the use of suitable variable transformations, the commonality of all extended magnetohydrodynamics (MHD) models is established. Remarkable correspondences between the Poisson brackets of inertialess Hall MHD and inertial MHD (which has electron inertia, but not the Hall drift) and extended MHD (which has both effects) are established. The helicities (two in all) for each of these models are obtained through these correspondences. The commonality of all the extended MHD models is traced to the existence of two Lie-dragged 2-forms, which are closely associated with the canonical momenta of the two underlying species. The Lie-dragging of these 2-forms by suitable velocities also leads to the correct equations of motion. The Hall MHD Poisson bracket is analyzed in detail, the Jacobi identity is verified through a detailed proof, and this proof ensures the Jacobi identity for the Poisson brackets of all the models.
Modelling extended lactations of dairy cows
Vargas, B.; Koops, W.J.; Herrero, M.; Arendonk, van J.A.M.
2000-01-01
Nine mathematical models were compared for their ability to predict daily milk yields (n = 294,986) in standard 305-d and extended lactations of dairy cows of Costa Rica. Lactations were classified by parity (first and later), lactation length (9 to 10, 11 to 12, 13 to 14, 15 to 16, and 16 to 17
Comprehensive asymmetric dark matter model
Lonsdale, Stephen J.; Volkas, Raymond R.
2018-01-01
Asymmetric dark matter (ADM) is motivated by the similar cosmological mass densities measured for ordinary and dark matter. We present a comprehensive theory for ADM that addresses the mass density similarity, going beyond the usual ADM explanations of similar number densities. It features an explicit matter-antimatter asymmetry generation mechanism, has one fully worked out thermal history and suggestions for other possibilities, and meets all phenomenological, cosmological and astrophysical...
Extended Higgs sectors in radiative neutrino models
Directory of Open Access Journals (Sweden)
Oleg Antipin
2017-05-01
Full Text Available Testable Higgs partners may be sought within the extensions of the SM Higgs sector aimed at generating neutrino masses at the loop level. We study a viability of extended Higgs sectors for two selected models of radiative neutrino masses: a one-loop mass model, providing the Higgs partner within a real triplet scalar representation, and a three-loop mass model, providing it within its two-Higgs-doublet sector. The Higgs sector in the one-loop model may remain stable and perturbative up to the Planck scale, whereas the three-loop model calls for a UV completion around 106 GeV. Additional vector-like lepton and exotic scalar fields, which are required to close one- and three-loop neutrino-mass diagrams, play a decisive role for the testability of the respective models. We constrain the parameter space of these models using LHC bounds on diboson resonances.
Topological Characterization of Extended Quantum Ising Models.
Zhang, G; Song, Z
2015-10-23
We show that a class of exactly solvable quantum Ising models, including the transverse-field Ising model and anisotropic XY model, can be characterized as the loops in a two-dimensional auxiliary space. The transverse-field Ising model corresponds to a circle and the XY model corresponds to an ellipse, while other models yield cardioid, limacon, hypocycloid, and Lissajous curves etc. It is shown that the variation of the ground state energy density, which is a function of the loop, experiences a nonanalytical point when the winding number of the corresponding loop changes. The winding number can serve as a topological quantum number of the quantum phases in the extended quantum Ising model, which sheds some light upon the relation between quantum phase transition and the geometrical order parameter characterizing the phase diagram.
Signatures of Extended Storage of Used Nuclear Fuel Comprehensive Final Report
Energy Technology Data Exchange (ETDEWEB)
Rauch, Eric Benton [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2016-09-21
This report serves as a comprehensive overview of the Extended Storage of Used Nuclear Fuel work performed for the Material Protection, Accounting and Control Technologies campaign under the Department of Energy Office of Nuclear Energy. This paper describes a signature based on the source and fissile material distribution found within a population of used fuel assemblies combined with the neutron absorbers found within cask design that is unique to a specific cask with its specific arrangement of fuel. The paper describes all the steps used in producing and analyzing this signature from the beginning to the project end.
Exploring Social Structures in Extended Team Model
DEFF Research Database (Denmark)
Zahedi, Mansooreh; Ali Babar, Muhammad
2013-01-01
Extended Team Model (ETM) as a type of offshore outsourcing is increasingly becoming popular mode of Global Software Development (GSD). There is little knowledge about the social structures in ETM and their impact on collaboration. Within a large interdisciplinary project to develop the next...... generation of GSD technologies, we are exploring the role of social structures to support collaboration. This paper reports some details of our research design and initial findings about the mechanisms to support social structures and their impact on collaboration in an ETM....
Directory of Open Access Journals (Sweden)
Katja Münster
2018-01-01
Full Text Available More and more findings suggest a tight temporal coupling between (non-linguistic socially interpreted context and language processing. Still, real-time language processing accounts remain largely elusive with respect to the influence of biological (e.g., age and experiential (e.g., world and moral knowledge comprehender characteristics and the influence of the ‘socially interpreted’ context, as for instance provided by the speaker. This context could include actions, facial expressions, a speaker’s voice or gaze, and gestures among others. We review findings from social psychology, sociolinguistics and psycholinguistics to highlight the relevance of (the interplay between the socially interpreted context and comprehender characteristics for language processing. The review informs the extension of an extant real-time processing account (already featuring a coordinated interplay between language comprehension and the non-linguistic visual context with a variable (‘ProCom’ that captures characteristics of the language user and with a first approximation of the comprehender’s speaker representation. Extending the CIA to the sCIA (social Coordinated Interplay Account is the first step toward a real-time language comprehension account which might eventually accommodate the socially situated communicative interplay between comprehenders and speakers.
Comprehensive model of a hermetic reciprocating compressor
Yang, B.; Ziviani, D.; Groll, E. A.
2017-08-01
A comprehensive simulation model is presented to predict the performance of a hermetic reciprocating compressor and to reveal the underlying mechanisms when the compressor is running. The presented model is composed of sub-models simulating the in-cylinder compression process, piston ring/journal bearing frictional power loss, single phase induction motor and the overall compressor energy balance among different compressor components. The valve model, leakage through piston ring model and in-cylinder heat transfer model are also incorporated into the in-cylinder compression process model. A numerical algorithm solving the model is introduced. The predicted results of the compressor mass flow rate and input power consumption are compared to the published compressor map values. Future work will focus on detailed experimental validation of the model and parametric studies investigating the effects of structural parameters, including the stroke-to-bore ratio, on the compressor performance.
Extended model for Richtmyer-Meshkov mix
Energy Technology Data Exchange (ETDEWEB)
Mikaelian, K O
2009-11-18
We examine four Richtmyer-Meshkov (RM) experiments on shock-generated turbulent mix and find them to be in good agreement with our earlier simple model in which the growth rate h of the mixing layer following a shock or reshock is constant and given by 2{alpha}A{Delta}v, independent of initial conditions h{sub 0}. Here A is the Atwood number ({rho}{sub B}-{rho}{sub A})/({rho}{sub B} + {rho}{sub A}), {rho}{sub A,B} are the densities of the two fluids, {Delta}V is the jump in velocity induced by the shock or reshock, and {alpha} is the constant measured in Rayleigh-Taylor (RT) experiments: {alpha}{sup bubble} {approx} 0.05-0.07, {alpha}{sup spike} {approx} (1.8-2.5){alpha}{sup bubble} for A {approx} 0.7-1.0. In the extended model the growth rate beings to day after a time t*, when h = h*, slowing down from h = h{sub 0} + 2{alpha}A{Delta}vt to h {approx} t{sup {theta}} behavior, with {theta}{sup bubble} {approx} 0.25 and {theta}{sup spike} {approx} 0.36 for A {approx} 0.7. They ascribe this change-over to loss of memory of the direction of the shock or reshock, signaling transition from highly directional to isotropic turbulence. In the simplest extension of the model h*/h{sub 0} is independent of {Delta}v and depends only on A. They find that h*/h{sub 0} {approx} 2.5-3.5 for A {approx} 0.7-1.0.
The importance of extended high viremics in models of HIV spread in South Africa.
Armbruster, Benjamin; Beck, Ekkehard C; Waheed, Mustafa
2014-06-01
Recent studies found a substantial fraction of 'extended high viremics' among HIV-1 subtype C, the most common subtype in southern Africa. Extended high viremics are HIV infected individuals who maintain a high viral load for a longer time period than usual after the initial infection. They are more infectious during this period, and their infection progresses to full-blown AIDS and death much faster than usual. This study investigates the impact of extended high viremics on the spread of the HIV epidemic in South Africa. We develop a simple deterministic compartmental model for HIV infection that includes extended high viremics. As the available data on extended high viremics are limited, we parameterize this model using only the fraction of extended high viremics among new infections and the reduced life-span of extended high viremics. We find that without extended high viremics, the HIV prevalence in South Africa would have remained close to its 1990 level, instead of increasing to the current epidemic levels. We also find that the greater the fraction of extended high viremics among susceptibles, the greater the steady-state HIV prevalence and the more sensitive the steady-state prevalence is to the HIV transmission probability. These results suggest that extended high viremics have an impact on the HIV epidemic in South Africa; justify the need for comprehensive epidemiological studies since the current data is limited; and suggest that future models of HIV for southern Africa should explicitly model extended high viremics.
The comprehensive process model of engagement.
Cohen-Mansfield, Jiska; Marx, Marcia S; Freedman, Laurence S; Murad, Havi; Regier, Natalie G; Thein, Khin; Dakheel-Ali, Maha
2011-10-01
Engagement refers to the act of being occupied or involved with an external stimulus. In dementia, engagement is the antithesis of apathy. The Comprehensive Process Model of Engagement was examined, in which environmental, personal, and stimulus characteristics impact the level of engagement. : Participants were 193 residents of 7 Maryland nursing with a diagnosis of dementia. Stimulus engagement was assessed via the Observational Measure of Engagement, measuring duration, attention, and attitude to the stimulus. Twenty-five stimuli were presented, which were categorized as live human social stimuli, simulated social stimuli, inanimate social stimuli, a reading stimulus, manipulative stimuli, a music stimulus, task and work-related stimuli, and two different self-identity stimuli. All stimuli elicited significantly greater engagement in comparison to the control stimulus. In the multivariate model, music significantly increased engagement duration, whereas all other stimuli significantly increased duration, attention, and attitude. Significant environmental variables in the multivariate model that increased engagement were: use of the long introduction with modeling (relative to minimal introduction), any level of sound (especially moderate sound), and the presence of between 2 and 24 people in the room. Significant personal attributes included Mini-Mental State Examination scores, activities of daily living performance and clarity of speech, which were positively associated with higher engagement scores. Results are consistent with the Comprehensive Process Model of Engagement. Personal attributes, environmental factors, and stimulus characteristics all contribute to the level and nature of engagement, with a secondary finding being that exposure to any stimulus elicits engagement in persons with dementia.
Evidence for geomagnetic jerks in comprehensive models
Chambodut, A.; Mandea, M.
2005-02-01
The rate of secular variation occasionally undergoes a sudden, sharp change, called a geomagnetic jerk. Such jerks have been detected in geomagnetic time series, centered—over the last four decades—around 1971, 1980, 1991, and 1999; others have been inferred from historical records. The geomagnetic jerks represent a reorganization of the secular variation, implying an internal origin, as established through spherical harmonic and wavelet analysis. However, some characteristics of jerks are not well understood. Here we estimate the occurrence dates for geomagnetic jerks, as they can be detected from a global geomagnetic model. This choice makes the present study novel, for two reasons. First, utilizing the comprehensive modelling approach allows for the use of a secular variation signal free of time-varying external fields and their corresponding induced counterpart, and observatory biases. Second, the model utilizes satellite data when available, in addition to observatory data. Indeed, POGO (1967 to 1971), MAGSAT (1979 to 1980), Ørsted (1999 to present time) and CHAMP (2000 to present time) satellite measurements help to separate the different magnetic sources. In this study the CM4 comprehensive model is used for a global search of geomagnetic jerks and their occurrence dates. Our first result indicates that found geomagnetic jerks might not have been worldwide in occurrence. Moreover, the obtained dates suggest that jerks detected in the CM4 model over the last four decades occurred not simultaneously but at slightly different times around 1971, 1980 and 1991.
Various Models for Reading Comprehension Process
Directory of Open Access Journals (Sweden)
Parastoo Babashamsi
2013-11-01
Full Text Available In recent years reading can be viewed as a process, as a form of thinking, as a true experience, and as a tool subject. As a process, reading includes visual discrimination, independent recognition of word, rhythmic progression along a line of print, precision in the return sweep of the eyes, and adjustment of rate. In the same line, the present paper aims at considering the various models of reading process. Moreover, the paper will take a look at various factors such as schema and vocabulary knowledge which affect reading comprehension process.
Description of a comprehensive mathematical model
DEFF Research Database (Denmark)
Li, Xiyan; Yin, Chungen
2017-01-01
Biomass gasification is still a promising technology after over 30 years’ research and development and has success only in a few niche markets. In this paper, a comprehensive mathematical model for biomass particle gasification is developed within a generic particle framework, assuming the feed...... evaporation, pyrolysis, heterogeneous char reactions, intra-particle heat and mass transfer, and changes in thermos-physical properties and so on, are properly taken into account to update the densities of various solid/liquid components in each cell as well as to provide source terms to the relevant gas...
Comprehensive decision tree models in bioinformatics.
Stiglic, Gregor; Kocbek, Simon; Pernek, Igor; Kokol, Peter
2012-01-01
Classification is an important and widely used machine learning technique in bioinformatics. Researchers and other end-users of machine learning software often prefer to work with comprehensible models where knowledge extraction and explanation of reasoning behind the classification model are possible. This paper presents an extension to an existing machine learning environment and a study on visual tuning of decision tree classifiers. The motivation for this research comes from the need to build effective and easily interpretable decision tree models by so called one-button data mining approach where no parameter tuning is needed. To avoid bias in classification, no classification performance measure is used during the tuning of the model that is constrained exclusively by the dimensions of the produced decision tree. The proposed visual tuning of decision trees was evaluated on 40 datasets containing classical machine learning problems and 31 datasets from the field of bioinformatics. Although we did not expected significant differences in classification performance, the results demonstrate a significant increase of accuracy in less complex visually tuned decision trees. In contrast to classical machine learning benchmarking datasets, we observe higher accuracy gains in bioinformatics datasets. Additionally, a user study was carried out to confirm the assumption that the tree tuning times are significantly lower for the proposed method in comparison to manual tuning of the decision tree. The empirical results demonstrate that by building simple models constrained by predefined visual boundaries, one not only achieves good comprehensibility, but also very good classification performance that does not differ from usually more complex models built using default settings of the classical decision tree algorithm. In addition, our study demonstrates the suitability of visually tuned decision trees for datasets with binary class attributes and a high number of possibly
Vectorial Representations of Meaning for a Computational Model of Language Comprehension
Wu, Stephen Tze-Inn
2010-01-01
This thesis aims to define and extend a line of computational models for text comprehension that are humanly plausible. Since natural language is human by nature, computational models of human language will always be just that--models. To the degree that they miss out on information that humans would tap into, they may be improved by considering…
One-dimensional extended Hubbard model in the atomic limit.
Mancini, F; Mancini, F P
2008-06-01
We present the exact solution of the one-dimensional extended Hubbard model in the atomic limit within the Green's function and equations of motion formalism. We provide a comprehensive and systematic analysis of the model by considering all the relevant response and correlation functions as well as thermodynamic quantities in the whole parameters space. At zero temperature we identify four phases in the plane (U,n) ( U is the on-site potential and n is the filling) and relative phase transitions as well as different types of charge ordering. These features are endorsed by investigating at T=0 the chemical potential and pertinent local correlators, the particle and double occupancy correlation functions, the entropy, and by studying the behavior in the limit T-->0 of the charge and spin susceptibilities. A detailed study of the thermodynamic quantities is also presented at finite temperature. This study evidences that a finite-range order persists for a wide range of the temperature, as shown by the behavior of the correlation functions and by the two-peak structure exhibited by the charge susceptibility and by the entropy. Moreover, the equations of motion formalism, together with the use of composite operators, allows us to exactly determine the set of elementary excitations. As a result, the density of states can be determined and a detailed analysis of the specific heat allows for identifying the excitations and for ascribing its two-peak structure to a redistribution of the charge density.
Extending models for two-dimensional constraints
DEFF Research Database (Denmark)
Forchhammer, Søren
2009-01-01
for models of two-dimensional constraints and as examples we apply it to the hard-square constraint and the no isolated bits (n.i.b) constraint. The iterative scaling can ensure that the entropy of the extension is optimized and that the entropy is increased compared to the initial model defined on 2 times 2...... elements. Application to a simple stationary model with hidden states is also outlined. For the n.i.b constraint, the initial model is based on elements defined by blocks of (1 times 2) binary symbols....
Micro dosimetry model. An extended version
Energy Technology Data Exchange (ETDEWEB)
Vroegindewey, C.
1994-07-01
In an earlier study a relative simple mathematical model has been constructed to simulate the energy transfer on a cellular scale and thus gain insight in the fundamental processes of BNCT. Based on this work, a more realistic micro dosimetry model is developed. The new facets of the model are: the treatment of proton recoil, the calculation of the distribution of energy depositions, and the determination of the number of particles crossing the target nucleus subdivided in place of origin. Besides these extensions, new stopping power tables for the emitted particles are generated and biased Monte Carlo techniques are used to reduce computer time. (orig.).
A Novel Biped Pattern Generator Based on Extended ZMP and Extended Cart-Table Model
Directory of Open Access Journals (Sweden)
Guangbin Sun
2015-07-01
Full Text Available This paper focuses on planning patterns for biped walking on complex terrains. Two problems are solved: ZMP (zero moment point cannot be used on uneven terrain, and the conventional cart-table model does not allow vertical CM (centre of mass motion. For the ZMP definition problem, we propose the extended ZMP (EZMP concept as an extension of ZMP to uneven terrains. It can be used to judge dynamic balance on universal terrains. We achieve a deeper insight into the connection and difference between ZMP and EZMP by adding different constraints. For the model problem, we extend the cart-table model by using a dynamic constraint instead of constant height constraint, which results in a mathematically symmetric set of three equations. In this way, the vertical motion is enabled and the resultant equations are still linear. Based on the extended ZMP concept and extended cart-table model, a biped pattern generator using triple preview controllers is constructed and implemented simultaneously to three dimensions. Using the proposed pattern generator, the Atlas robot is simulated. The simulation results show the robot can walk stably on rather complex terrains by accurately tracking extended ZMP.
MacDonald, Deborah J.; Blazer, Kathleen R.; Weitzel, Jeffrey N.
2012-01-01
Rapidly evolving genetic and genomic technologies for genetic cancer risk assessment (GCRA) are revolutionizing our approach to targeted therapy and cancer screening and prevention, heralding the era of personalized medicine. Although many academic medical centers provide GCRA services, most people receive their medical care in the community setting. Yet, few community clinicians have the knowledge or time needed to adequately select, apply and interpret genetic/genomic tests. This article describes alternative approaches to the delivery of GCRA services, profiling the City of Hope Cancer Screening & Prevention Program Network (CSPPN) academic and community-based health center partnership as a model for the delivery of the highest quality evidence-based GCRA services while promoting research participation in the community setting. Growth of the CSPPN was enabled by information technology, with videoconferencing for telemedicine and web conferencing for remote participation in interdisciplinary genetics tumor boards. Grant support facilitated the establishment of an underserved minority outreach clinic in the regional County hospital. Innovative clinician education, technology and collaboration are powerful tools to extend GCRA expertise from a NCI-designated Comprehensive Cancer Center, enabling diffusion of evidenced-base genetic/genomic information and best practice into the community setting. PMID:20495088
Extending the prevalent consumer loyalty modelling
DEFF Research Database (Denmark)
Olsen, Svein Ottar; Tudoran, Ana Alina; Brunsø, Karen
2013-01-01
Purpose: This study addresses the role of habit strength in explaining loyalty behaviour. Design/methodology/approach: The study uses 2063 consumers’ data from a survey in Denmark and Spain, and multigroup structural equation modelling to analyse the data. The paper describes an approach employing...... the psychological meanings of the habit construct, such as automaticity, lack of awareness or very little conscious deliberation. Findings: The findings suggest that when habits start to develop and gain strength, less planning is involved, and that the loyalty behaviour sequence mainly occurs guided...... by automaticity and inertia. A new model with habit strength as a mediator between satisfaction and loyalty behaviour provides a substantial increase in explained variance in loyalty behaviour over the traditional model with intention as a mediator. Originality/value: This study contributes to the existent...
Extended Linear Models with Gaussian Priors
DEFF Research Database (Denmark)
Quinonero, Joaquin
2002-01-01
on the parameters. The Relevance Vector Machine, introduced by Tipping, is a particular case of such a model. I give the detailed derivations of the expectation-maximisation (EM) algorithm used in the training. These derivations are not found in the literature, and might be helpful for newcomers....
Extending Social Cognition Models of Health Behaviour
Abraham, Charles; Sheeran, Paschal; Henderson, Marion
2011-01-01
A cross-sectional study assessed the extent to which indices of social structure, including family socio-economic status (SES), social deprivation, gender and educational/lifestyle aspirations correlated with adolescent condom use and added to the predictive utility of a theory of planned behaviour model. Analyses of survey data from 824 sexually…
Extending product modeling methods for integrated product development
DEFF Research Database (Denmark)
Bonev, Martin; Wörösch, Michael; Hauksdóttir, Dagný
2013-01-01
. Updated design requirements have then to be made explicit and mapped against the existing product architecture. In this paper, existing methods are adapted and extended through linking updated requirements to suitable product models. By combining several established modeling techniques, such as the DSM......Despite great efforts within the modeling domain, the majority of methods often address the uncommon design situation of an original product development. However, studies illustrate that development tasks are predominantly related to redesigning, improving, and extending already existing products...
Developing linguistic literacy: a comprehensive model.
Ravid, Dorit; Tolchinsky, Liliana
2002-05-01
This is a position paper modelling the domain of linguistic literacy and its development through the life span. It aims to provide a framework for the analysis of language development in the school years, integrating sociolinguistic and psycholinguistic notions of variation, language awareness, and literacy in a comprehensive model. The paper focuses on those aspects of literacy competence that are expressed in language as well as aspects of linguistic knowledge that are affected by literacy competence, tracing the route that children take in appropriating linguistic literacy as part of their cognitive abilities and examining the effect of literacy on language across development. Our view of linguistic literacy consists of one defining feature: control over linguistic variation from both a user-dependent ('lectal') and a context-dependent (modality, genre, and register) perspective; of one concomitant process: metalanguage and its role in language development; and of one condition: familiarity with writing and written language from two aspects: written language as discourse style--the recognition that the kind of language used for writing is essentially different from the one used for speech; and written language as a notational system--the perception and growing command of the representational system that is used in the written modality. Linguistic literacy is viewed as a constituent of language knowledge characterized by the availability of multiple linguistic resources and by the ability to consciously access one's own linguistic knowledge and to view language from various perspectives.
Developing and Extending a Cyberinfrastructure Model
Energy Technology Data Exchange (ETDEWEB)
Alvarez, Rosio
2007-11-13
Increasingly, research and education institutions are realizing the strategic value and challenge of deploying and supporting institutional cyberinfrastructure (CI). Cyberinfrastructure is composed of high performance computing systems, massive storage systems, visualization systems, and advanced networks to interconnect the components within and across institutions and research communities. CI also includes the professionals with expertise in scientific application and algorithm development and parallel systems operation. Unlike ?regular? IT infrastructure, the manner in which the components are configured and skills to do so are highly specific and specialized. Planning and coordinating these assets is a fundamental step toward enhancing an institution?s research competitiveness and return on personnel, technology, and facilities investments. Coordinated deployment of CI assets has implications across the institution. Consider the VC for Research whose new faculty in the Life Sciences are now asking for simulation systems rather than wet labs, or the Provost who lost another faculty candidate to a peer institution that offered computational support for research, or the VC for Administration who has seen a spike in power and cooling demands from many of the labs and office spaces being converted to house systems. These are just some of the issues that research institutions are wrestling with as research becomes increasingly computational, data-intensive and interdisciplinary. This bulletin will discuss these issues and will present an approach for developing a cyberinfrastructure model that was successfully developed at one institution and then deployed across institutions.
Extended models for nosocomial infection: parameter estimation and model selection.
Thomas, Alun; Khader, Karim; Redd, Andrew; Leecaster, Molly; Zhang, Yue; Jones, Makoto; Greene, Tom; Samore, Matthew
2017-10-12
We consider extensions to previous models for patient level nosocomial infection in several ways, provide a specification of the likelihoods for these new models, specify new update steps required for stochastic integration, and provide programs that implement these methods to obtain parameter estimates and model choice statistics. Previous susceptible-infected models are extended to allow for a latent period between initial exposure to the pathogen and the patient becoming themselves infectious, and the possibility of decolonization. We allow for multiple facilities, such as acute care hospitals or long-term care facilities and nursing homes, and for multiple units or wards within a facility. Patient transfers between units and facilities are tracked and accounted for in the models so that direct importation of a colonized individual from one facility or unit to another might be inferred. We allow for constant transmission rates, rates that depend on the number of colonized individuals in a unit or facility, or rates that depend on the proportion of colonized individuals. Statistical analysis is done in a Bayesian framework using Markov chain Monte Carlo methods to obtain a sample of parameter values from their joint posterior distribution. Cross validation, deviance information criterion and widely applicable information criterion approaches to model choice fit very naturally into this framework and we have implemented all three. We illustrate our methods by considering model selection issues and parameter estimation for data on methicilin-resistant Staphylococcus aureus surveillance tests over 1 year at a Veterans Administration hospital comprising seven wards. © The authors 2017. Published by Oxford University Press on behalf of the Institute of Mathematics and its Applications. All rights reserved.
Extending Research on Oral Reading Fluency Measures, Reading Speed, and Comprehension
Schall, Megan; Skinner, Christopher H.; Cazzell, Samantha; Ciancio, Dennis; Ruddy, Jonah; Thompson, Kelly
2016-01-01
Middle-school students completed a comprehension assessment. The following day, they read four, 120-word passages, two standard and two non-standard ransom-note passages with altered font sizes. Altering font sizes increased students' reading time (i.e., reduced reading speed) by an average of 3 s and decreased students' words correct per minute…
Effects of Note-Taking and Extended Writing on Expository Text Comprehension: Who Benefits?
Hebert, Michael; Graham, Steve; Rigby-Wills, Hope; Ganson, Katie
2014-01-01
Writing may be an especially useful tool for improving the reading comprehension of lower performing readers and students with disabilities. However, it is reasonable to expect that students with poor writing skills in particular, may actually be less adept at using writing to improve their reading skills, and may not be able to do so without…
Building and testing models with extended Higgs sectors
Ivanov, Igor P.
2017-07-01
Models with non-minimal Higgs sectors represent a mainstream direction in theoretical exploration of physics opportunities beyond the Standard Model. Extended scalar sectors help alleviate difficulties of the Standard Model and lead to a rich spectrum of characteristic collider signatures and astroparticle consequences. In this review, we introduce the reader to the world of extended Higgs sectors. Not pretending to exhaustively cover the entire body of literature, we walk through a selection of the most popular examples: the two- and multi-Higgs-doublet models, as well as singlet and triplet extensions. We will show how one typically builds models with extended Higgs sectors, describe the main goals and the challenges which arise on the way, and mention some methods to overcome them. We will also describe how such models can be tested, what are the key observables one focuses on, and illustrate the general strategy with a subjective selection of results.
Towards a comprehensive model of feather regeneration.
Maderson, Paul F A; Hillenius, Willem J; Hiller, Uwe; Dove, Carla C
2009-10-01
Understanding of the regeneration of feathers, despite a 140 year tradition of study, has remained substantially incomplete. Moreover, accumulated errors and mis-statements in the literature have confounded the intrinsic difficulties in describing feather regeneration. Lack of allusion to Rudall's (Rudall [1947] Biochem Biophys Acta 1:549-562) seminal X-ray diffraction study that revealed two distinct keratins, beta- and alpha-, in a mature feather, is one of the several examples where lack of citation long inhibited progress in understanding. This article reviews and reevaluates the available literature and provides a synthetic, comprehensive, morphological model for the regeneration of a generalized, adult contour feather. Particular attention is paid to several features that have previously been largely ignored. Some of these, such as the beta-keratogenic sheath and the alpha-keratogenic, supra-umbilical, pulp caps, are missing from mature, functional feathers sensu stricto because they are lost through preening, but these structures nevertheless play a critical role in development. A new developmental role for a tissue unique to feathers, the medullary pith of the rachis and barb rami, and especially its importance in the genesis of the superior umbilical region (SUR) that forms the transition from the spathe (rachis and vanes) to the calamus, is described. It is postulated that feathers form through an intricate interplay between cyto- and histodifferentiative processes, determined by patterning signals that emanate from the dermal core, and a suite of interacting biomechanical forces. Precisely regulated patterns of loss of intercellular adhesivity appear to be the most fundamental aspect of feather morphogenesis and regeneration: rather than a hierarchically branched structure, it appears more appropriate to conceive of feathers as a sheet of mature keratinocytes that is "full of holes. 2009 Wiley-Liss, Inc.
Extended-release divalproex in bipolar and other psychiatric disorders: A comprehensive review
Directory of Open Access Journals (Sweden)
Steven C Stoner
2007-01-01
Full Text Available Steven C Stoner1, Megan M Dahmen21Northwest Missouri Psychiatric Rehabilitation Center, Department of Pharmacy, St. Joseph, Missouri, USA; 2University of Missouri-Kansas City School of Pharmacy, Division of Pharmacy Practice, Kansas City, Missouri, USAAbstract: Bipolar disorder can be a devastating disease state for individuals with the disease and also for family members. Proper recognition and treatment is vital to the successful management of this disease state. Through increased community and practitioner awareness, along with efforts to increase awareness for proper assessment, the rate of diagnosed bipolar disorder is increasing. Recent years have brought about the introduction of several new medications with approved indications for the treatment of bipolar disorder. In addition to new agents, traditional mood stabilizing medications have also been released in different formulations to better enhance tolerability without jeopardizing efficacy. One particular product is extended-release divalproex sodium. In the following article, we review the clinical presentation of bipolar disorder, its epidemiology, and the pharmacokinetics and mechanism of action for divalproex. In addition, we specifically review the role of extended-release divalproex in bipolar disorder through a critical analysis of the currently available published primary literature.Keywords: extended-release divalproex, divalproex, bipolar disorder, mania, depression
Statistical model of stress corrosion cracking based on extended ...
Indian Academy of Sciences (India)
The mechanism of stress corrosion cracking (SCC) has been discussed for decades. Here I propose a model of SCC reflecting the feature of fracture in brittle manner based on the variational principle under approximately supposed thermal equilibrium. In that model the functionals are expressed with extended forms of ...
Extended Hubbard models for ultracold atoms in optical lattices
Energy Technology Data Exchange (ETDEWEB)
Juergensen, Ole
2015-06-05
In this thesis, the phase diagrams and dynamics of various extended Hubbard models for ultracold atoms in optical lattices are studied. Hubbard models are the primary description for many interacting particles in periodic potentials with the paramount example of the electrons in solids. The very same models describe the behavior of ultracold quantum gases trapped in the periodic potentials generated by interfering beams of laser light. These optical lattices provide an unprecedented access to the fundamentals of the many-particle physics that govern the properties of solid-state materials. They can be used to simulate solid-state systems and validate the approximations and simplifications made in theoretical models. This thesis revisits the numerous approximations underlying the standard Hubbard models with special regard to optical lattice experiments. The incorporation of the interaction between particles on adjacent lattice sites leads to extended Hubbard models. Offsite interactions have a strong influence on the phase boundaries and can give rise to novel correlated quantum phases. The extended models are studied with the numerical methods of exact diagonalization and time evolution, a cluster Gutzwiller approximation, as well as with the strong-coupling expansion approach. In total, this thesis demonstrates the high relevance of beyond-Hubbard processes for ultracold atoms in optical lattices. Extended Hubbard models can be employed to tackle unexplained problems of solid-state physics as well as enter previously inaccessible regimes.
Disordered Supersolids in the Extended Bose-Hubbard Model.
Lin, Fei; Maier, T A; Scarola, V W
2017-10-06
The extended Bose-Hubbard model captures the essential properties of a wide variety of physical systems including ultracold atoms and molecules in optical lattices, Josephson junction arrays, and certain narrow band superconductors. It exhibits a rich phase diagram including a supersolid phase where a lattice solid coexists with a superfluid. We use quantum Monte Carlo to study the supersolid part of the phase diagram of the extended Bose-Hubbard model on the simple cubic lattice. We add disorder to the extended Bose-Hubbard model and find that the maximum critical temperature for the supersolid phase tends to be suppressed by disorder. But we also find a narrow parameter window in which the supersolid critical temperature is enhanced by disorder. Our results show that supersolids survive a moderate amount of spatial disorder and thermal fluctuations in the simple cubic lattice.
Creating a Generic Extended Enterprise Management Model using GERAM
DEFF Research Database (Denmark)
Larsen, Lars Bjørn; Kaas-Pedersen, Carsten; Vesterager, Johan
1998-01-01
of virtual enterprises. Through the introduction of GERAM (Generalised Enterprise Reference Architecture and Methodology) an initial version of a basic framework for extended enterprise management is introduced. This basic framework is the first step towards the creation of a generic extended enterprise......The two main themes of the Globeman21 (Global Manufacturing in the 21st century) project are product life cycle management and extended enterprise management. This article focus on the later of these subjects and an illustration of the concept is given together with a discussion of the concept...... management model. By working with GERAM in relation to extended enterprise management it has been found that it provides a useful background for organising knowledge, experience and the activities within the project...
A Lattice Model of the Development of Reading Comprehension.
Connor, Carol McDonald
2016-12-01
In this article, I present a developmental model of how children learn to comprehend what they read, which builds on current models of reading comprehension and integrates findings from instructional research and evidence-based models of development in early and middle childhood. The lattice model holds that children's developing reading comprehension is a function of the interacting, reciprocal, and bootstrapping effects of developing text-specific, linguistic, and social-cognitive processes, which interact with instruction as child-characteristic-by-instruction (CXI) interaction effects. The processes develop over time and in the context of classroom, home, peer, community, and other influences to affect children's development of proficient reading comprehension. I first describe models of reading comprehension. I then review the basic processes in the model, the role of instruction, and CXI interactions in the context of the lattice model. I then discuss implications for instruction and research.
Monte Carlo modelling of an extended DXA technique
Michael, G. J.; Henderson, C. J.
1998-09-01
The precision achieved in measuring bone mineral density (BMD) by commercial dual-energy x-ray absorptiometry (DXA) machines is typically better than 1%, but accuracy is considerably worse. Errors, due to inhomogeneous distributions of fat, of up to 10% have been reported. These errors arise because the DXA technique assumes a two-component model for the human body, i.e. bone mineral and soft tissue. This paper describes an extended DXA technique that uses a three-component model of human tissue and significantly reduces errors due to inhomogeneous fat distribution. In addition to two x-ray transmission measurements, a measurement of the path length of the x-ray beam within the patient is required. This provides a third equation, i.e. where T, , and are the total, lean soft tissue, bone mineral and fatty tissue thicknesses respectively. Monte Carlo modelling was undertaken to make a comparison of the standard and extended DXA techniques in the presence of inhomogeneous fat distribution. Two geometries of varying complexity were simulated. In each case the extended DXA technique produced BMD measurements that were independent of soft tissue composition whereas the standard technique produced BMD measurements that were strongly dependent on soft tissue composition. For example, in one case, the gradients of the plots of BMD versus fractional fat content were for standard DXA and for extended DXA . In all cases the extended DXA method produced more accurate but less precise results than the standard DXA technique.
An Assessment Model for Proof Comprehension in Undergraduate Mathematics
Mejia-Ramos, Juan Pablo; Fuller, Evan; Weber, Keith; Rhoads, Kathryn; Samkoff, Aron
2012-01-01
Although proof comprehension is fundamental in advanced undergraduate mathematics courses, there has been limited research on what it means to understand a mathematical proof at this level and how such understanding can be assessed. In this paper, we address these issues by presenting a multidimensional model for assessing proof comprehension in…
Extended Cellular Automata Models of Particles and Space-Time
Beedle, Michael
2005-04-01
Models of particles and space-time are explored through simulations and theoretical models that use Extended Cellular Automata models. The expanded Cellular Automata Models consist go beyond simple scalar binary cell-fields, into discrete multi-level group representations like S0(2), SU(2), SU(3), SPIN(3,1). The propagation and evolution of these expanded cellular automatas are then compared to quantum field theories based on the "harmonic paradigm" i.e. built by an infinite number of harmonic oscillators, and with gravitational models.
Extended period simulation (EPS) modelling of urban water ...
African Journals Online (AJOL)
Water distribution network was constructed, calibrated and validated for extended period simulation studies using the network's physical, operational, calibration and validation data. The model was then applied to evaluate: (i) effects of fluctuating water demand on system storage over 24 hour period and (ii) level of service ...
The one-dimensional extended Bose–Hubbard model
Indian Academy of Sciences (India)
Unknown
We use the finite-size, density-matrix-renormalization-group (DMRG) ... excitations; other topics in quantum fluids and solids; liquid and solid helium. ..... 3. Conclusions. In conclusion, then, we have studied the complete phase diagram of the one-dimensional, extended Bose–Hubbard model for mean boson density ρ= 1 by ...
The Extended Parallel Process Model: Illuminating the Gaps in Research
Popova, Lucy
2012-01-01
This article examines constructs, propositions, and assumptions of the extended parallel process model (EPPM). Review of the EPPM literature reveals that its theoretical concepts are thoroughly developed, but the theory lacks consistency in operational definitions of some of its constructs. Out of the 12 propositions of the EPPM, a few have not…
Comprehensive FDTD modelling of photonic crystal waveguide components
DEFF Research Database (Denmark)
Lavrinenko, Andrei; Borel, Peter Ingo; Frandsen, Lars Hagedorn
2004-01-01
Planar photonic crystal waveguide structures have been modelled using the finite-difference-time-domain method and perfectly matched layers have been employed as boundary conditions. Comprehensive numerical calculations have been performed and compared to experimentally obtained transmission spec...
Comprehensive Care For Joint Replacement Model - Provider Data
U.S. Department of Health & Human Services — Comprehensive Care for Joint Replacement Model - provider data. This data set includes provider data for two quality measures tracked during an episode of care:...
Bollenbach, Carolyn
1986-01-01
Teaching comprehension skills requires teaching to intuition with activities such as presenting puzzling situations to introduce a topic, using art to elicit latent feelings, using imagery and improvisations to enhance visualization, and using music and dance to encourage nonverbal expressions. (DB)
Mixing Paradigms for More Comprehensible Models
DEFF Research Database (Denmark)
Westergaard, Michael; Slaats, Tijs
2013-01-01
features of models, or processes which are highly dynamic, overly complex. Declarative modeling, such as is supported by Declare and DCR graphs, focus on control-flow, but does not specify it explicitly; instead specifications come in the form of constraints on the order or appearance of tasks...
Constructing Multidatabase Collections Using Extended ODMG Object Model
Directory of Open Access Journals (Sweden)
Adrian Skehill Mark Roantree
1999-11-01
Full Text Available Collections are an important feature in database systems. They provide us with the ability to group objects of interest together, and then to manipulate them in the required fashion. The OASIS project is focused on the construction a multidatabase prototype which uses the ODMG model and a canonical model. As part of this work we have extended the base model to provide a more powerful collection mechanism, and to permit the construction of a federated collection, a collection of heterogenous objects taken from distributed data sources
Extended Cann Model for Behavioral Modeling of Envelope Tracking Power Amplifiers
DEFF Research Database (Denmark)
Tafuri, Felice Francesco; Larsen, Torben
2013-01-01
extending the well-known Cann model. The Cann model is extended including the modulated supply voltage Venv as a new independent variable, enhancing the AM/AM model so that it can mimic PA memory effects and defining a dynamic nonlinear AM/PM function that can model the phase distortions introduced...
Comprehensive areal model of residential heating demands
Energy Technology Data Exchange (ETDEWEB)
Tessmer, R.G. Jr.
1978-01-01
Data sources and methodology for modeling annual residential heating demands are described. A small areal basis is chosen, census tract or minor civil division, to permit estimation of demand densities and economic evaluation of community district heating systems. The demand model is specified for the entire nation in order to provide general applicability and to permit validation with other published fuel consumption estimates for 1970.
General Friction Model Extended by the Effect of Strain Hardening
DEFF Research Database (Denmark)
Nielsen, Chris V.; Martins, Paulo A.F.; Bay, Niels
2016-01-01
contact area as function of the normalized contact pressure is based on slip-line analysis and hence on the assumption of rigid-ideally plastic material behavior. In the present work, a general finite element model is established to, firstly, reproduce the original model under the assumption of rigid......-ideally plastic material, and secondly, to extend the solution by the influence of material strain hardening. This corresponds to adding a new variable and, therefore, a new axis to the general friction model. The resulting model is presented in a combined function suitable for e.g. finite element modeling...... of friction in metal forming, where the material generally strain hardens. The extension of the model to cover strain hardening materials is validated by comparison to previously published experimental data....
Extended cox regression model: The choice of timefunction
Isik, Hatice; Tutkun, Nihal Ata; Karasoy, Durdu
2017-07-01
Cox regression model (CRM), which takes into account the effect of censored observations, is one the most applicative and usedmodels in survival analysis to evaluate the effects of covariates. Proportional hazard (PH), requires a constant hazard ratio over time, is the assumptionofCRM. Using extended CRM provides the test of including a time dependent covariate to assess the PH assumption or an alternative model in case of nonproportional hazards. In this study, the different types of real data sets are used to choose the time function and the differences between time functions are analyzed and discussed.
Modeling human comprehension of data visualizations
Energy Technology Data Exchange (ETDEWEB)
Matzen, Laura E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Haass, Michael Joseph [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Divis, Kristin Marie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wilson, Andrew T. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
2017-09-01
This project was inspired by two needs. The first is a need for tools to help scientists and engineers to design effective data visualizations for communicating information, whether to the user of a system, an analyst who must make decisions based on complex data, or in the context of a technical report or publication. Most scientists and engineers are not trained in visualization design, and they could benefit from simple metrics to assess how well their visualization's design conveys the intended message. In other words, will the most important information draw the viewer's attention? The second is the need for cognition-based metrics for evaluating new types of visualizations created by researchers in the information visualization and visual analytics communities. Evaluating visualizations is difficult even for experts. However, all visualization methods and techniques are intended to exploit the properties of the human visual system to convey information efficiently to a viewer. Thus, developing evaluation methods that are rooted in the scientific knowledge of the human visual system could be a useful approach. In this project, we conducted fundamental research on how humans make sense of abstract data visualizations, and how this process is influenced by their goals and prior experience. We then used that research to develop a new model, the Data Visualization Saliency Model, that can make accurate predictions about which features in an abstract visualization will draw a viewer's attention. The model is an evaluation tool that can address both of the needs described above, supporting both visualization research and Sandia mission needs.
Various Models for Reading Comprehension Process
Parastoo Babashamsi; Saeideh Bolandifar; Nahid Shakib
2013-01-01
In recent years reading can be viewed as a process, as a form of thinking, as a true experience, and as a tool subject. As a process, reading includes visual discrimination, independent recognition of word, rhythmic progression along a line of print, precision in the return sweep of the eyes, and adjustment of rate. In the same line, the present paper aims at considering the various models of reading process. Moreover, the paper will take a look at various factors such as schema and vocabular...
Phenomenological comparison of models with extended Higgs sectors
Mühlleitner, Margarete; Sampaio, Marco O. P.; Santos, Rui; Wittbrodt, Jonas
2017-08-01
Beyond the Standard Model (SM) extensions usually include extended Higgs sectors. Models with singlet or doublet fields are the simplest ones that are compatible with the ρ parameter constraint. The discovery of new non-SM Higgs bosons and the identification of the underlying model requires dedicated Higgs properties analyses. In this paper, we compare several Higgs sectors featuring 3 CP-even neutral Higgs bosons that are also motivated by their simplicity and their ability to solve some of the flaws of the SM. They are: the SM extended by a complex singlet field (CxSM), the singlet extension of the 2-Higgs-Doublet Model (N2HDM), and the Next-to-Minimal Supersymmetric SM extension (NMSSM). In addition, we analyse the CP-violating 2-Higgs-Doublet Model (C2HDM), which provides 3 neutral Higgs bosons with a pseudoscalar admixture. This allows us to compare the effects of singlet and pseudoscalar admixtures. Through dedicated scans of the allowed parameter space of the models, we analyse the phenomenologically viable scenarios from the view point of the SM-like Higgs boson and of the signal rates of the non-SM-like Higgs bosons to be found. In particular, we analyse the effect of singlet/pseudoscalar admixture, and the potential to differentiate these models in the near future. This is supported by a study of couplings sums of the Higgs bosons to massive gauge bosons and to fermions, where we identify features that allow us to distinguish the models, in particular when only part of the Higgs spectrum is discovered. Our results can be taken as guidelines for future LHC data analyses, by the ATLAS and CMS experiments, to identify specific benchmark points aimed at revealing the underlying model.
Phenomenological comparison of models with extended Higgs sectors
Energy Technology Data Exchange (ETDEWEB)
Muehlleitner, Margarete [Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany). Inst. for Theoretical Physics; Sampaio, Marco O.P. [Aveiro Univ. e CIDMA (Portugal). Dept. de Fisica; Santos, Rui [Instituto Politecnico de Lisboa (Portugal). ISEL - Instituto Superior de Engenharia de Lisboa; Lisboa Univ. (Portugal). Centro de Fisica Teorica e Computacional; Univ. do Minho, Braga (Portugal). LIP, Dept. de Fisica; Wittbrodt, Jonas [Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany). Inst. for Theoretical Physics; Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)
2017-03-22
Beyond the Standard Model (SM) extensions usually include extended Higgs sectors. Models with singlet or doublet fields are the simplest ones that are compatible with the ρ parameter constraint. The discovery of new non-SM Higgs bosons and the identification of the underlying model requires dedicated Higgs properties analyses. In this paper, we compare several Higgs sectors featuring 3 CP-even neutral Higgs bosons that are also motivated by their simplicity and their capability to solve some of the flaws of the SM. They are: the SM extended by a complex singlet field (C x SM), the singlet extension of the 2-Higgs-Doublet Model (N2HDM), and the Next-to-Minimal Supersymmetric SM extension (NMSSM). In addition, we analyse the CP-violating 2-Higgs-Doublet Model (C2HDM), which provides 3 neutral Higgs bosons with a pseudoscalar admixture. This allows us to compare the effects of singlet and pseudoscalar admixtures. Through dedicated scans of the allowed parameter space of the models, we analyse the phenomenologically viable scenarios from the view point of the SM-like Higgs boson and of the signal rates of the non-SM-like Higgs bosons to be found. In particular, we analyse the effect of singlet/pseudoscalar admixture, and the potential to differentiate these models in the near future. This is supported by a study of couplings sums of the Higgs bosons to massive gauge bosons and to fermions, where we identify features that allow us to distinguish the models, in particular when only part of the Higgs spectrum is discovered. Our results can be taken as guidelines for future LHC data analyses, by the ATLAS and CMS experiments, to identify specific benchmark points aimed at revealing the underlying model.
Wave speeds in the macroscopic extended model for ultrarelativistic gases
Energy Technology Data Exchange (ETDEWEB)
Borghero, F., E-mail: borghero@unica.it [Dip. Matematica e Informatica, Università di Cagliari, Via Ospedale 72, 09124 Cagliari (Italy); Demontis, F., E-mail: fdemontis@unica.it [Dip. Matematica, Università di Cagliari, Viale Merello 92, 09123 Cagliari (Italy); Pennisi, S., E-mail: spennisi@unica.it [Dip. Matematica, Università di Cagliari, Via Ospedale 72, 09124 Cagliari (Italy)
2013-11-15
Equations determining wave speeds for a model of ultrarelativistic gases are investigated. This model is already present in literature; it deals with an arbitrary number of moments and it was proposed in the context of exact macroscopic approaches in Extended Thermodynamics. We find these results: the whole system for the determination of the wave speeds can be divided into independent subsystems which are expressed by linear combinations, through scalar coefficients, of tensors all of the same order; some wave speeds, but not all of them, are expressed by square roots of rational numbers; finally, we prove that these wave speeds for the macroscopic model are the same of those furnished by the kinetic model.
Extended Group Contribution Model for Polyfunctional Phase Equilibria
DEFF Research Database (Denmark)
Abildskov, Jens
-liquid equilibria from data on binary mixtures, composed of structurally simple molecules with a single functional group. More complex is the situation with mixtures composed of structurally more complicated molecules or molecules with more than one functional group. The UNIFAC method is extended to handle...... on ideas applied to modelling of pure component properties. Chapter 2 describes the conceptual background of the approach. Three extensions of the present first-order UNIFAC model are formulated in chapter 3. These obey the Gibbs-Duhem restriction, and satisfy other traditional consistency requirements....... In chapter 4 parameters are estimated for the first-order UNIFAC model, based on which parameters are estimated for one of the second-order models described in chapter 3. The parameter estimation is based on measured binary data on around 4000 systems, covering 11 C-, H- and O-containing functional groups...
Developing a Model of Teaching Reading Comprehension for EFL Students
Hamra, Arifuddin; Syatriana, Eny
2010-01-01
This study aimed at designing a model of teaching reading comprehension based on the objectives of teaching reading at the senior high school and the teachers' understanding of the school curriculum and to describe the implementation of the model. The subject consisted of 24 teachers, 167 students of five SMAs (senior high schools) in South…
A Parallel Distributed Processing Model of Story Comprehension and Recall.
Golden, Richard M.; Rumelhart, David E.
1993-01-01
Introduces a multistate probabilistic causal chain notation for describing the knowledge structures implicitly represented by the subjective conditional probability distribution. Proposes a psychological process model of how story comprehension and recall processes operate using causal chain representations. Compares the model's story-recall…
OSeMOSYS Energy Modeling Using an Extended UTOPIA Model
Lavigne, Denis
2017-01-01
The OSeMOSYS project offers open-access energy modeling to a wide audience. Its relative simplicity makes it appealing for academic research and governmental organizations to study the impacts of policy decisions on an energy system in the context of possibly severe greenhouse gases emissions limitations. OSeMOSYS is a tool that enhances the…
Extended Neural Metastability in an Embodied Model of Sensorimotor Coupling
Aguilera, Miguel; Bedia, Manuel G.; Barandiaran, Xabier E.
2016-01-01
The hypothesis that brain organization is based on mechanisms of metastable synchronization in neural assemblies has been popularized during the last decades of neuroscientific research. Nevertheless, the role of body and environment for understanding the functioning of metastable assemblies is frequently dismissed. The main goal of this paper is to investigate the contribution of sensorimotor coupling to neural and behavioral metastability using a minimal computational model of plastic neural ensembles embedded in a robotic agent in a behavioral preference task. Our hypothesis is that, under some conditions, the metastability of the system is not restricted to the brain but extends to the system composed by the interaction of brain, body and environment. We test this idea, comparing an agent in continuous interaction with its environment in a task demanding behavioral flexibility with an equivalent model from the point of view of “internalist neuroscience.” A statistical characterization of our model and tools from information theory allow us to show how (1) the bidirectional coupling between agent and environment brings the system closer to a regime of criticality and triggers the emergence of additional metastable states which are not found in the brain in isolation but extended to the whole system of sensorimotor interaction, (2) the synaptic plasticity of the agent is fundamental to sustain open structures in the neural controller of the agent flexibly engaging and disengaging different behavioral patterns that sustain sensorimotor metastable states, and (3) these extended metastable states emerge when the agent generates an asymmetrical circular loop of causal interaction with its environment, in which the agent responds to variability of the environment at fast timescales while acting over the environment at slow timescales, suggesting the constitution of the agent as an autonomous entity actively modulating its sensorimotor coupling with the world. We
Extending Primitive Spatial Data Models to Include Semantics
Reitsma, F.; Batcheller, J.
2009-04-01
Our traditional geospatial data model involves associating some measurable quality, such as temperature, or observable feature, such as a tree, with a point or region in space and time. When capturing data we implicitly subscribe to some kind of conceptualisation. If we can make this explicit in an ontology and associate it with the captured data, we can leverage formal semantics to reason with the concepts represented in our spatial data sets. To do so, we extend our fundamental representation of geospatial data in a data model by including a URI in our basic data model that links it to our ontology defining our conceptualisation, We thus extend Goodchild et al's geo-atom [1] with the addition of a URI: (x, Z, z(x), URI) . This provides us with pixel or feature level knowledge and the ability to create layers of data from a set of pixels or features that might be drawn from a database based on their semantics. Using open source tools, we present a prototype that involves simple reasoning as a proof of concept. References [1] M.F. Goodchild, M. Yuan, and T.J. Cova. Towards a general theory of geographic representation in gis. International Journal of Geographical Information Science, 21(3):239-260, 2007.
Extended Nambu-Jona-Lasinio Model vs QCD Sum Rules
Yamawaki, Koichi; Zakharov, V.I.
1994-01-01
We argue that the extended Nambu-Jona-Lasinio model of hadrons can be be probed and constrained in a nontrivial way via QCD sum rules. While there arise rather restrictive bounds on the strength of the effective four-fermion interaction in the vector channel, introduction of the four-fermion interaction in the pseudoscalar channel could resolve a long standing puzzle of QCD sum rules. We speculate also on possible connection between effective four-quark interactions describing the low-energy ...
An extended lattice model accounting for traffic jerk
Redhu, Poonam; Siwach, Vikash
2018-02-01
In this paper, a flux difference lattice hydrodynamics model is extended by considering the traffic jerk effect which comes due to vehicular motion of non-motor automobiles. The effect of traffic jerk has been examined through linear stability analysis and shown that it can significantly enlarge the unstable region on the phase diagram. To describe the phase transition of traffic flow, mKdV equation near the critical point is derived through nonlinear stability analysis. The theoretical findings have been verified using numerical simulation which confirms that the jerk parameter plays an important role in stabilizing the traffic jam efficiently in sensing the flux difference of leading sites.
Extending the transdiagnostic model of attachment and psychopathology
Directory of Open Access Journals (Sweden)
Tsachi eEin-Dor
2016-03-01
Full Text Available Research has suggested that high levels of attachment insecurities that are formed through interactions with significant others are associated with a general vulnerability to mental disorders. In the present paper, we extend Ein-Dor and Doron's (2015 transdiagnostic model linking attachment orientations with internalizing and externalizing symptoms, to include thought disorder spectrum symptoms. Specifically, we speculate on the processes that mediate the linkage between attachment insecurities and psychosis and obsessive compulsive disorder (OCD symptoms, and indicate the different contexts that might set a trajectory of one individual to one set of symptoms while another individual to a different set of symptoms.
Extending the Modelling Framework for Gas-Particle Systems
DEFF Research Database (Denmark)
Rosendahl, Lasse Aistrup
An extended Lagrangian particle tracking and combustion model for non-conventional solid fuels such as chopped straw has been developed. Based on an extension of the existing tracking techniques, shapes are based on a superelliptic equation capable of assuming forms ranging from spheres...... to cylinders, through simple parameter variation. Using a concept of aerodynamical similarity, a drag coefficient accounting for orientability as well as shape variations has been defined. The model has been applied to two isothermal testcases, where different types of particles are injected into swirling flow...... configurations. In both cases, the model performs efficiently, and indicates a pronounced difference in terms of the aerodynamic properties of the different particle shapes. For validation purposes, terminal velocity predictions of different shapes have been carried out, and compared to experimental data...
An extended differentiated optical services model for WDM optical networks
Ouyang, Yong; Zeng, Qingji; Wei, Wei
2004-04-01
The need to provide QoS-guaranteed services in the WDM optical networks is becoming increasingly important because of a variety of candidate client networks (e.g., IP, ATM, SONET/SDH) and the requirement for QoS-delivery within the transport layers. This article addresses the QoS problem and presents a framework of QoS provisioning in the WDM optical network. We first characterize the QoS problem in the WDM optical network by comparing with that in the traditional networks. Then we propose a QoS service model in the optical domain called extended differentiated optical services (E-DoS) model based on a set of optical parameters that captures the quality, the reliability and the priority of an optical connection. Each component of the E-DoS model has been analyzed in detail in this article.
Extended Nonnegative Tensor Factorisation Models for Musical Sound Source Separation
Directory of Open Access Journals (Sweden)
Derry FitzGerald
2008-01-01
Full Text Available Recently, shift-invariant tensor factorisation algorithms have been proposed for the purposes of sound source separation of pitched musical instruments. However, in practice, existing algorithms require the use of log-frequency spectrograms to allow shift invariance in frequency which causes problems when attempting to resynthesise the separated sources. Further, it is difficult to impose harmonicity constraints on the recovered basis functions. This paper proposes a new additive synthesis-based approach which allows the use of linear-frequency spectrograms as well as imposing strict harmonic constraints, resulting in an improved model. Further, these additional constraints allow the addition of a source filter model to the factorisation framework, and an extended model which is capable of separating mixtures of pitched and percussive instruments simultaneously.
Experimental validation of the multiphase extended Leblond's model
Weisz-Patrault, Daniel
2017-10-01
Transformation induced plasticity is a crucial contribution of the simulation of several forming processes involving phase transitions under mechanical loads, resulting in large irreversible strain even though the applied stress is under the yield stress. One of the most elegant and widely used models is based on analytic homogenization procedures and has been proposed by Leblond et al. [1-4]. Very recently, a simple extension of the Leblond's model has been developed by Weisz-Patrault [8]. Several product phases are taken into account and several assumptions are relaxed in order to extend the applicability of the model. The present contribution compares experimental tests with numerical computations, in order to discuss the validity of the developed theory. Thus, experimental results extracted from the existing literature are analyzed. Results show a good agreement between measurements and theoretical computations.
Tighe, Elizabeth L.; Schatschneider, Christopher
2016-01-01
This study extended the findings of Tighe and Schatschneider (2015) by investigating the predictive utility of separate dimensions of morphological awareness as well as vocabulary knowledge to reading comprehension in adult basic education (ABE) students. We competed two- and three-factor structural equation models of reading comprehension. A three-factor model of real word morphological awareness, pseudoword morphological awareness, and vocabulary knowledge emerged as the best fit and accounted for 79% of the reading comprehension variance. The results indicated that the constructs contributed jointly to reading comprehension; however, vocabulary knowledge was the only potentially unique predictor (p = 0.052), accounting for an additional 5.6% of the variance. This study demonstrates the feasibility of applying a latent variable modeling approach to examine individual differences in the reading comprehension skills of ABE students. Further, this study replicates the findings of Tighe and Schatschneider (2015) on the importance of differentiating among dimensions of morphological awareness in this population. PMID:26869981
Tighe, Elizabeth L; Schatschneider, Christopher
2016-01-01
This study extended the findings of Tighe and Schatschneider (2015) by investigating the predictive utility of separate dimensions of morphological awareness as well as vocabulary knowledge to reading comprehension in adult basic education (ABE) students. We competed two- and three-factor structural equation models of reading comprehension. A three-factor model of real word morphological awareness, pseudoword morphological awareness, and vocabulary knowledge emerged as the best fit and accounted for 79% of the reading comprehension variance. The results indicated that the constructs contributed jointly to reading comprehension; however, vocabulary knowledge was the only potentially unique predictor (p = 0.052), accounting for an additional 5.6% of the variance. This study demonstrates the feasibility of applying a latent variable modeling approach to examine individual differences in the reading comprehension skills of ABE students. Further, this study replicates the findings of Tighe and Schatschneider (2015) on the importance of differentiating among dimensions of morphological awareness in this population.
Extending the cascading gravity model to lower dimensions
Hao, Peng; Stojkovic, Dejan
2014-07-01
The cascading gravity model was proposed to eliminate instabilities of the original Dvali, Gabadadze, Porrati model by embedding our 4D (where D refers to the number of space-time dimensions) Universe into a 5D brane, which is itself embedded in a 6D bulk. Thus gravity cascades from 6D down to 4D as we decrease the length scales. We show that it is possible to extend this setup to lower dimensions as well, i.e. there is a self-consistent embedding of a 3D brane into a 4D brane, which is itself embedded in a 5D bulk and so on. This extension fits well into the "vanishing dimensions" framework in which dimensions open up as we increase the length scales.
Situation models, mental simulations, and abstract concepts in discourse comprehension
R.A. Zwaan (Rolf)
2016-01-01
textabstractThis article sets out to examine the role of symbolic and sensorimotor representations in discourse comprehension. It starts out with a review of the literature on situation models, showing how mental representations are constrained by linguistic and situational factors. These ideas are
A Process Model for the Comprehension of Organic Chemistry Notation
Havanki, Katherine L.
2012-01-01
This dissertation examines the cognitive processes individuals use when reading organic chemistry equations and factors that affect these processes, namely, visual complexity of chemical equations and participant characteristics (expertise, spatial ability, and working memory capacity). A six stage process model for the comprehension of organic…
Analysis of the phase structure in extended Higgs models
Energy Technology Data Exchange (ETDEWEB)
Seniuch, M.
2006-07-07
We study the generation of the baryon asymmetry in the context of electroweak baryogenesis in two different extensions of the Standard Model. First, we consider an effective theory, in which the Standard Model is augmented by an additional dimension-six Higgs operator. The effects of new physics beyond a cut-off scale are parameterized by this operator. The second model is the two-Higgs-doublet model, whose particle spectrum is extended by two further neutral and two charged heavy Higgs bosons. In both cases we focus on the properties of the electroweak phase transition, especially on its strength and the profile of the nucleating bubbles. After reviewing some general aspects of the electroweak phase transition and baryogenesis we derive the respective thermal effective potentials to one-loop order. We systematically study the parameter spaces, using numerical methods, and compute the strength of the phase transition and the wall thickness as a function of the Higgs masses. We find a strong first order transition for a light Higgs state with a mass up to about 200 GeV. In case of the dimension-six model the cut-off scale has to stay between 500 and 850 GeV, in the two-Higgs-doublet model one needs at least one heavy Higgs mass of 300 GeV. The wall thickness varies for both theories in the range roughly from two to fifteen, in units of the inverse critical temperature. We also estimate the size of the electron and neutron electric dipole moments, since new sources of CP violation give rise to them. In wide ranges of the parameter space we are not in conflict with the experimental bounds. Finally the baryon asymmetry, which is predicted by these models, is related to the Higgs mass and the other appropriate input parameters. In both models the measured baryon asymmetry can be achieved for natural values of the model parameters. (orig.)
Extended nonlinear feedback model for describing episodes of high inflation
Szybisz, Martín A.; Szybisz, Leszek
2017-01-01
An extension of the nonlinear feedback (NLF) formalism to describe regimes of hyper- and high-inflation in economy is proposed in the present work. In the NLF model the consumer price index (CPI) exhibits a finite time singularity of the type 1 /(tc - t) (1 - β) / β, with β > 0, predicting a blow up of the economy at a critical time tc. However, this model fails in determining tc in the case of weak hyperinflation regimes like, e.g., that occurred in Israel. To overcome this trouble, the NLF model is extended by introducing a parameter γ, which multiplies all terms with past growth rate index (GRI). In this novel approach the solution for CPI is also analytic being proportional to the Gaussian hypergeometric function 2F1(1 / β , 1 / β , 1 + 1 / β ; z) , where z is a function of β, γ, and tc. For z → 1 this hypergeometric function diverges leading to a finite time singularity, from which a value of tc can be determined. This singularity is also present in GRI. It is shown that the interplay between parameters β and γ may produce phenomena of multiple equilibria. An analysis of the severe hyperinflation occurred in Hungary proves that the novel model is robust. When this model is used for examining data of Israel a reasonable tc is got. High-inflation regimes in Mexico and Iceland, which exhibit weaker inflations than that of Israel, are also successfully described.
Directory of Open Access Journals (Sweden)
Michael Phillips
Full Text Available BACKGROUND: Comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GCxGC-TOF MS has been proposed as a powerful new tool for multidimensional analysis of complex chemical mixtures. We investigated GCxGC-TOF MS as a new method for identifying volatile organic compounds (VOCs in normal human breath. METHODS: Samples of alveolar breath VOCs and ambient room air VOC were collected with a breath collection apparatus (BCA onto separate sorbent traps from 34 normal healthy volunteers (mean age = 40 yr, SD = 17 yr, male/female = 19/15. VOCs were separated on two serial capillary columns separated by a cryogenic modulator, and detected with TOF MS. The first and second dimension columns were non-polar and polar respectively. RESULTS: BCA collection combined with GC×GC-TOF MS analysis identified approximately 2000 different VOCs in samples of human breath, many of which have not been previously reported. The 50 VOCs with the highest alveolar gradients (abundance in breath minus abundance in ambient room air mostly comprised benzene derivatives, acetone, methylated derivatives of alkanes, and isoprene. CONCLUSIONS: Collection and analysis of breath VOCs with the BCA-GC×GC-TOF MS system extended the size of the detectable human volatile metabolome, the volatome, by an order of magnitude compared to previous reports employing one-dimensional GC-MS. The size of the human volatome has been under-estimated in the past due to coelution of VOCs in one-dimensional GC analytical systems.
A comprehensive elementary model of the mammalian circulatory system.
Sandquist, G M; Olsen, D B; Kolff, W J
1982-01-01
Beginning with a set of simplifying assumptions and the statements for the hydrodynamic and thermodynamic processes involved, a comprehensive mathematical model for the mammalian circulatory system is developed and evaluated. Analytical relationships are derived and examined for the circulatory component pressures, flow rates, blood volumes, flow resistances, pumping power and pumping rate. The essential circulatory model parameters are identified and inspected for their influence upon circulatory behavior. A complete and consistent set of circulatory model parameters is given for the adult human male and the model response is examined. In general, agreement of the model predictions for man with experimental data is good.
Neutrino Oscillations in Extended Anti-GUT Model
Froggatt, C.D.; Takanishi, Y.
2000-01-01
What we call the Anti-GUT model is extended a bit to include also right-handed neutrinos and thus make use of the see-saw mechanism for neutrino masses. This model consists in assigning gauge quantum numbers to the known Weyl fermions and the three see-saw right-handed neutrinos. Each family (generation) is given its own Standard Model gauge fields and a gauge field coupled to the $B-L$ quantum number for that family alone. Further we assign a rather limited number of Higgs fields, so as to break these gauge groups down to the Standard Model gauge group and to fit, w.r.t. order of magnitude, the spectra and mixing angles of the quarks and leptons. We find a rather good fit, which for neutrino oscillations favours the small mixing angle MSW solution, although the mixing angle predicted is closest to the upper side of the uncertainty range for the measured solar neutrino mixing angle. An idea for making a ``finetuning''-principle to ``explain'' the large ratios found empirically in physics, and answer such ques...
A multifluid model extended for strong temperature nonequilibrium
Energy Technology Data Exchange (ETDEWEB)
Chang, Chong [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2016-08-08
We present a multifluid model in which the material temperature is strongly affected by the degree of segregation of each material. In order to track temperatures of segregated form and mixed form of the same material, they are defined as different materials with their own energy. This extension makes it necessary to extend multifluid models to the case in which each form is defined as a separate material. Statistical variations associated with the morphology of the mixture have to be simplified. Simplifications introduced include combining all molecularly mixed species into a single composite material, which is treated as another segregated material. Relative motion within the composite material, diffusion, is represented by material velocity of each component in the composite material. Compression work, momentum and energy exchange, virtual mass forces, and dissipation of the unresolved kinetic energy have been generalized to the heterogeneous mixture in temperature nonequilibrium. The present model can be further simplified by combining all mixed forms of materials into a composite material. Molecular diffusion in this case is modeled by the Stefan-Maxwell equations.
Phase diagram of the triangular extended Hubbard model.
Tocchio, Luca F; Gros, Claudius; Zhang, Xue-Feng; Eggert, Sebastian
2014-12-12
We study the extended Hubbard model on the triangular lattice as a function of filling and interaction strength. The complex interplay of kinetic frustration and strong interactions on the triangular lattice leads to exotic phases where long-range charge order, antiferromagnetic order, and metallic conductivity can coexist. Variational Monte Carlo simulations show that three kinds of ordered metallic states are stable as a function of nearest neighbor interaction and filling. The coexistence of conductivity and order is explained by a separation into two functional classes of particles: part of them contributes to the stable order, while the other part forms a partially filled band on the remaining substructure. The relation to charge ordering in charge transfer salts is discussed.
Extending 3D city models with legal information
Frank, A. U.; Fuhrmann, T.; Navratil, G.
2012-10-01
3D city models represent existing physical objects and their topological and functional relations. In everyday life the rights and responsibilities connected to these objects, primarily legally defined rights and obligations but also other socially and culturally established rights, are of importance. The rights and obligations are defined in various laws and it is often difficult to identify the rules applicable for a certain case. The existing 2D cadastres show civil law rights and obligations and plans to extend them to provide information about public law restrictions for land use are in several countries under way. It is tempting to design extensions to the 3D city models to provide information about legal rights in 3D. The paper analyses the different types of information that are needed to reduce conflicts and to facilitate decisions about land use. We identify the role 3D city models augmented with planning information in 3D can play, but do not advocate a general conversion from 2D to 3D for the legal cadastre. Space is not anisotropic and the up/down dimension is practically very different from the two dimensional plane - this difference must be respected when designing spatial information systems. The conclusions are: (1) continue the current regime for ownership of apartments, which is not ownership of a 3D volume, but co-ownership of a building with exclusive use of some rooms; such exclusive use rights could be shown in a 3D city model; (2) ownership of 3D volumes for complex and unusual building situations can be reported in a 3D city model, but are not required everywhere; (3) indicate restrictions for land use and building in 3D city models, with links to the legal sources.
New extended standard model, dark matters and relativity theory
Hwang, Jae-Kwang
2016-03-01
Three-dimensional quantized space model is newly introduced as the extended standard model. Four three-dimensional quantized spaces with total 12 dimensions are used to explain the universes including ours. Electric (EC), lepton (LC) and color (CC) charges are defined to be the charges of the x1x2x3, x4x5x6 and x7x8x9 warped spaces, respectively. Then, the lepton is the xi(EC) - xj(LC) correlated state which makes 3x3 = 9 leptons and the quark is the xi(EC) - xj(LC) - xk(CC) correlated state which makes 3x3x3 = 27 quarks. The new three bastons with the xi(EC) state are proposed as the dark matters seen in the x1x2x3 space, too. The matter universe question, three generations of the leptons and quarks, dark matter and dark energy, hadronization, the big bang, quantum entanglement, quantum mechanics and general relativity are briefly discussed in terms of this new model. The details can be found in the article titled as ``journey into the universe; three-dimensional quantized spaces, elementary particles and quantum mechanics at https://www.researchgate.net/profile/J_Hwang2''.
Extended MHD modeling of nonlinear instabilities in fusion and space plasmas
Energy Technology Data Exchange (ETDEWEB)
Germaschewski, Kai [Univ. of New Hampshire, Durham, NH (United States)
2017-11-15
A number of different sub-projects where pursued within this DOE early career project. The primary focus was on using fully nonlinear, curvilinear, extended MHD simulations of instabilities with applications to fusion and space plasmas. In particular, we performed comprehensive studies of the dynamics of the double tearing mode in different regimes and confi gurations, using Cartesian and cyclindrical geometry and investigating both linear and non-linear dynamics. In addition to traditional extended MHD involving Hall term and electron pressure gradient, we also employed a new multi-fluid moment model, which shows great promise to incorporate kinetic effects, in particular off-diagonal elements of the pressure tensor, in a fluid model, which is naturally computationally much cheaper than fully kinetic particle or Vlasov simulations. We used our Vlasov code for detailed studies of how weak collisions effect plasma echos. In addition, we have played an important supporting role working with the PPPL theory group around Will Fox and Amitava Bhattacharjee on providing simulation support for HED plasma experiments performed at high-powered laser facilities like OMEGA-EP in Rochester, NY. This project has support a great number of computational advances in our fluid and kinetic plasma models, and has been crucial to winning multiple INCITE computer time awards that supported our computational modeling.
Doublon dynamics in the extended Fermi-Hubbard model
Hofmann, Felix; Potthoff, Michael
2012-05-01
Two fermions occupying the same site of a lattice model with strongly repulsive Hubbard-type interaction U form a doublon, a long-living excitation, the decay of which is suppressed because of energy conservation. By means of an exact-diagonalization approach based on the Krylov-space technique, we study the dynamics of a single doublon, of two doublons, and of a doublon in the presence of two additional fermions prepared locally in the initial state of the extended Hubbard model. The time dependence of the expectation value of the double occupancy at the different sites of a large one-dimensional lattice is analyzed by perturbative arguments. In this way the spatiotemporal evolution of the doublon can be understood. The initial decay takes place on a short time scale 1/U, and the long-time average of the decayed fraction of the total double occupancy scales as 1/U2. We demonstrate how the dynamics of a doublon in the initial state is related to the spectrum of two-fermion excitations obtained from linear-response theory, we work out the difference between doublons composed of fermions vs doublons composed of bosons, and we show that despite the increase of phase space for inelastic decay processes, the stability of a doublon is enhanced by the presence of additional fermions on an intermediate time scale.
Toward a comprehensive areal model of earthquake-induced landslides
Miles, S.B.; Keefer, D.K.
2009-01-01
This paper provides a review of regional-scale modeling of earthquake-induced landslide hazard with respect to the needs for disaster risk reduction and sustainable development. Based on this review, it sets out important research themes and suggests computing with words (CW), a methodology that includes fuzzy logic systems, as a fruitful modeling methodology for addressing many of these research themes. A range of research, reviewed here, has been conducted applying CW to various aspects of earthquake-induced landslide hazard zonation, but none facilitate comprehensive modeling of all types of earthquake-induced landslides. A new comprehensive areal model of earthquake-induced landslides (CAMEL) is introduced here that was developed using fuzzy logic systems. CAMEL provides an integrated framework for modeling all types of earthquake-induced landslides using geographic information systems. CAMEL is designed to facilitate quantitative and qualitative representation of terrain conditions and knowledge about these conditions on the likely areal concentration of each landslide type. CAMEL is highly modifiable and adaptable; new knowledge can be easily added, while existing knowledge can be changed to better match local knowledge and conditions. As such, CAMEL should not be viewed as a complete alternative to other earthquake-induced landslide models. CAMEL provides an open framework for incorporating other models, such as Newmark's displacement method, together with previously incompatible empirical and local knowledge. ?? 2009 ASCE.
A Comprehensive and Harmonized Digital Forensic Investigation Process Model.
Valjarevic, Aleksandar; Venter, Hein S
2015-11-01
Performing a digital forensic investigation (DFI) requires a standardized and formalized process. There is currently neither an international standard nor does a global, harmonized DFI process (DFIP) exist. The authors studied existing state-of-the-art DFIP models and concluded that there are significant disparities pertaining to the number of processes, the scope, the hierarchical levels, and concepts applied. This paper proposes a comprehensive model that harmonizes existing models. An effort was made to incorporate all types of processes proposed by the existing models, including those aimed at achieving digital forensic readiness. The authors introduce a novel class of processes called concurrent processes. This is a novel contribution that should, together with the rest of the model, enable more efficient and effective DFI, while ensuring admissibility of digital evidence. Ultimately, the proposed model is intended to be used for different types of DFI and should lead to standardization. © 2015 American Academy of Forensic Sciences.
Extended Hubbard model on a C{sub 20} molecule
Energy Technology Data Exchange (ETDEWEB)
Lin Fei [Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Soerensen, Erik S [Department of Physics and Astronomy, McMaster University, Hamilton, ON, L8S 4M1 (Canada); Kallin, Catherine [Department of Physics and Astronomy, McMaster University, Hamilton, ON, L8S 4M1 (Canada); Berlinsky, A John [Department of Physics and Astronomy, McMaster University, Hamilton, ON, L8S 4M1 (Canada)
2007-11-14
The electronic correlations on a C{sub 20} molecule, as described by an extended Hubbard Hamiltonian with a nearest-neighbor Coulomb interaction of strength V, are studied using quantum Monte Carlo and exact diagonalization methods. For electron-doped C{sub 20}, it is known that pair binding arising from a purely electronic mechanism is absent within the standard Hubbard model (V = 0). Here we show that this is also the case for hole doping for 0
An Extended Production and Inspection Model with Nonrigid Demand
Directory of Open Access Journals (Sweden)
Neng-Hui Shih
2013-01-01
Full Text Available This paper extends a previous production and inspection (PI model in relation to market demand that is nonrigid to consider an imperfect process that has a general hazard rate instead of a constant failure rate. Products are produced by an imperfect process that may shift randomly from the IN state to the OUT state. When the process is in the OUT state, it has a higher probability of producing a nonconforming product than when it is in the IN state. To achieve the zero defects policy, all products before delivery to the market should be inspected and the inspection order follows their production sequence. Furthermore, the inspection information from all previous products is used to decide either that the next candidate product should be inspected or that the inspection procedure for the current production lot should be terminated. When the inspection procedure is terminated, the remaining unmet demand is regarded as a shortage. An algorithm is developed to determine an optimal PI policy that minimizes the expected total cost, which includes the cost of inspection, of shortage, and of production.
Kuilman, Maartje; Karlsson, Bodil; Benze, Susanne; Megner, Linda
2017-11-01
Ice particles in the summer mesosphere - such as those connected to noctilucent clouds and polar mesospheric summer echoes - have since their discovery contributed to the uncovering of atmospheric processes on various scales ranging from interactions on molecular levels to global scale circulation patterns. While there are numerous model studies on mesospheric ice microphysics and how the clouds relate to the background atmosphere, there are at this point few studies using comprehensive global climate models to investigate observed variability and climatology of noctilucent clouds. In this study it is explored to what extent the large-scale inter-annual characteristics of noctilucent clouds are captured in a 30-year run - extending from 1979 to 2009 - of the nudged and extended version of the Canadian Middle Atmosphere Model (CMAM30). To construct and investigate zonal mean inter-seasonal variability in noctilucent cloud occurrence frequency and ice mass density in both hemispheres, a simple cloud model is applied in which it is assumed that the ice content is solely controlled by the local temperature and water vapor volume mixing ratio. The model results are compared to satellite observations, each having an instrument-specific sensitivity when it comes to detecting noctilucent clouds. It is found that the model is able to capture the onset dates of the NLC seasons in both hemispheres as well as the hemispheric differences in NLCs, such as weaker NLCs in the SH than in the NH and differences in cloud height. We conclude that the observed cloud climatology and zonal mean variability are well captured by the model.
Comprehensive Power Losses Model for Electronic Power Transformer
DEFF Research Database (Denmark)
Yue, Quanyou; Li, Canbing; Cao, Yijia
2018-01-01
The electronic power transformer (EPT) has highe rpower losses than the conventional transformer. However, the EPT can correct the power factor, compensate the unbalanced current and reduce the line power losses in the distribution network.Therefore, the higher losses of the EPT and the consequent......-losses and considering the impact of the non-unity power factor and the three-phase unbalanced current, the overall power losses in the distribution network when using the EPT to replace the conventional transformer is analyzed, and the conditions in which the application of the EPT can cause less power losses...... reduced power losses in the distribution network require a comprehensive consideration when comparing the power losses of theEPT and conventional transformer. In this paper, a comprehensive power losses analysis model for the EPT in distribution networks is proposed. By analyzing the EPT self...
Tam, Ka-Ming; Tsai, Shan-Wen; Campbell, David K.
2014-01-01
The search for realistic one-dimensional (1D) models that exhibit dominant superconducting (SC) fluctuations effects has a long history. In these 1D systems, the effects of commensurate band fillings—strongest at half-filling—and electronic repulsions typically lead to a finite charge gap and the favoring of insulating density wave ordering over superconductivity. Accordingly, recent proposals suggesting a gapless metallic state in the Holstein-Hubbard (HH) model, possibly superconducting, have generated considerable interest and controversy, with the most recent work demonstrating that the putative dominant superconducting state likely does not exist. In this paper we study a model with nonlocal electron-phonon interactions, in addition to electron-electron interactions. This model unambiguously possesses dominant superconducting fluctuations at half filling in a large region of parameter space. Using both the numerical multi-scale functional renormalization group (MFRG) for the full model and an analytic conventional renormalization group for a bosonized version of the model, we demonstrate the existence of these dominant SC fluctuations and show that they arise because the spin-charge coupling at high energies is weakened by the nonlocal electron-phonon interaction and the charge gap is destroyed by the resultant suppression of the Umklapp process. The existence of the dominant SC pairing instability in this half-filled 1D system suggests that nonlocal boson-mediated interactions may be important in the superconductivity observed in the organic superconductors.
Modeling of heavy metal salt solubility using the Extended UNIQUAC model
DEFF Research Database (Denmark)
Iliuta, Maria Cornelia; Thomsen, Kaj; Rasmussen, Peter
2002-01-01
Solid-liquid equilibria in complex aqueous systems involving a heavy metal cation (Mn2+, Fe2+, Co2+, Ni2+, Cu2+, or Zn2+) and one or more ions for which Extended UNIQUAC parameters have been published previously are modeled using the Extended UNIQUAC model. Model parameters are determined on the ...... on the basis of a data bank with more than 4, 000 experimental data points for binary and ternary aqueous systems. The parameters are generally valid in the temperature range from the freezing point to the boiling point of the respective solutions....
Thermodynamic modelling of acid gas removal from natural gas using the Extended UNIQUAC model
DEFF Research Database (Denmark)
Sadegh, Negar; Stenby, Erling Halfdan; Thomsen, Kaj
2017-01-01
Thermodynamics of natural gas sweetening process needs to be known for proper design of natural gas treating plants. Absorption with aqueous N-Methyldiethanolamine is currently the most commonly used process for removal of acid gas (CO2 and H2S) impurities from natural gas. Model parameters...... for the Extended UNIQUAC model have already been determined by the same authors to calculate single acid gas solubility in aqueous MDEA. In this study, the model is further extended to estimate solubility of CO2 and H2S and their mixture in aqueous MDEA at high pressures with methane as a makeup gas....
Tong, Shijie
Energy storage is one of society's grand challenges for the 21st century. Lithium ion batteries (LIBs) are widely used in mobile devices, transportation, and stationary energy storages due to lowering cost combined with excellent power/energy density as well as cycle durability. The need for a battery management system (BMS) arises from a demand to improve cycle life, assure safety, and optimize the full pack performance. In this work, we proposed a model based battery on-line state of charge (SoC) and state of health (SoH) estimator for LIBs. The estimator incorporates a comprehensive Equivalent Circuit Model (ECM) as reference, an Extended Kalman Filter (EKF) as state observer, a Recursive Least Square (RLS) algorithm as parameter identifier, and Parameter Varying Approach (PVA) based optimization algorithms for the parameter function regressions. The developed adaptive estimator was applied to a 10kW smart grid energy storage application using retired electric vehicle batteries. The estimator exhibits a high numerical efficiency as well as an excellent accuracy in estimating SoC and SoH. The estimator also provides a novel method to optimize the correlation between battery open circuit voltage (OCV) and SoC, which further improves states estimation accuracy.
Cognitive Modeling of Individual Variation in Reference Production and Comprehension
Directory of Open Access Journals (Sweden)
Petra eHendriks
2016-04-01
Full Text Available A challenge for most theoretical and computational accounts of linguistic reference is the observation that language users vary considerably in their referential choices. Part of the variation observed among and within language users and across tasks may be explained from variation in the cognitive resources available to speakers and listeners. This paper presents a computational model of reference production and comprehension developed within the cognitive architecture ACT-R. Through simulations with this ACT-R model, it is investigated how cognitive constraints interact with linguistic constraints and features of the linguistic discourse in speakers’ production and listeners’ comprehension of referring expressions in specific tasks, and how this interaction may give rise to variation in referential choice. The ACT-R model of reference explains and predicts variation among language users in their referential choices as a result of individual and task-related differences in processing speed and working memory capacity. Because of limitations in their cognitive capacities, speakers sometimes underspecify or overspecify their referring expressions, and listeners sometimes choose incorrect referents or are overly liberal in their interpretation of referring expressions.
Cognitive Modeling of Individual Variation in Reference Production and Comprehension
Hendriks, Petra
2016-01-01
A challenge for most theoretical and computational accounts of linguistic reference is the observation that language users vary considerably in their referential choices. Part of the variation observed among and within language users and across tasks may be explained from variation in the cognitive resources available to speakers and listeners. This paper presents a computational model of reference production and comprehension developed within the cognitive architecture ACT-R. Through simulations with this ACT-R model, it is investigated how cognitive constraints interact with linguistic constraints and features of the linguistic discourse in speakers’ production and listeners’ comprehension of referring expressions in specific tasks, and how this interaction may give rise to variation in referential choice. The ACT-R model of reference explains and predicts variation among language users in their referential choices as a result of individual and task-related differences in processing speed and working memory capacity. Because of limitations in their cognitive capacities, speakers sometimes underspecify or overspecify their referring expressions, and listeners sometimes choose incorrect referents or are overly liberal in their interpretation of referring expressions. PMID:27092101
Meyler, Ann; Keller, Timothy A.; Cherkassky, Vladimir L.; Gabrieli, John D. E.; Just, Marcel Adam
2008-01-01
This study used fMRI to longitudinally assess the impact of intensive remedial instruction on cortical activation among 5th grade poor readers during a sentence comprehension task. The children were tested at three time points: prior to remediation, after 100 h of intensive instruction, and 1 year after the instruction had ended. Changes in brain…
Gelzheiser, Lynn M.; Scanlon, Donna; Vellutino, Frank; Hallgren-Flynn, Laura; Schatschneider, Christopher
2011-01-01
To implement Response to Intervention with intermediate-grade struggling readers, there is a need for interventions that are responsive to individual student needs, and sufficiently comprehensive to support the many dimensions of the reading process. This research examined the efficacy of such an intervention, the Interactive Strategies…
A comprehensive model of simultaneous denitrification and methanogenic fermentation processes.
Tugtas, A Evren; Tezel, U; Pavlostathis, Spyros G
2010-01-01
The denitrification process was incorporated into the IWA Anaerobic Digestion Model No. 1 (ADM1) in order to account for the effect of denitrification on the methanogenic fermentation process. The model was calibrated and optimized using previously published experimental data and kinetic parameter values obtained with a mixed, mesophilic (35 degrees C) methanogenic culture. Model simulations were used to predict the effect of nitrate reduction on the methanogenic fermentation process in batch, semi-continuous, and continuous flow reactors experiencing operational changes and/or system disturbances. The extended model clearly revealed the importance of substrate competition between denitrifiers and non-denitrifiers as well as the impact of N-oxide inhibition on process interactions between fermentation, methanogenesis, and denitrification.
Park, Yu Rang; Yoon, Young Jo; Jang, Tae Hun; Seo, Hwa Jeong; Kim, Ju Han
2014-01-01
Extension of the standard model while retaining compliance with it is a challenging issue because there is currently no method for semantically or syntactically verifying an extended data model. A metadata-based extended model, named CCR+, was designed and implemented to achieve interoperability between standard and extended models. Furthermore, a multilayered validation method was devised to validate the standard and extended models. The American Society for Testing and Materials (ASTM) Community Care Record (CCR) standard was selected to evaluate the CCR+ model; two CCR and one CCR+ XML files were evaluated. In total, 188 metadata were extracted from the ASTM CCR standard; these metadata are semantically interconnected and registered in the metadata registry. An extended-data-model-specific validation file was generated from these metadata. This file can be used in a smartphone application (Health Avatar CCR+) as a part of a multilayered validation. The new CCR+ model was successfully evaluated via a patient-centric exchange scenario involving multiple hospitals, with the results supporting both syntactic and semantic interoperability between the standard CCR and extended, CCR+, model. A feasible method for delivering an extended model that complies with the standard model is presented herein. There is a great need to extend static standard models such as the ASTM CCR in various domains: the methods presented here represent an important reference for achieving interoperability between standard and extended models.
An extended rational thermodynamics model for surface excess fluxes
Sagis, L.M.C.
2012-01-01
In this paper, we derive constitutive equations for the surface excess fluxes in multiphase systems, in the context of an extended rational thermodynamics formalism. This formalism allows us to derive Maxwell–Cattaneo type constitutive laws for the surface extra stress tensor, the surface thermal
DEFF Research Database (Denmark)
Jørgensen, Peter Løchte
Extended Nelson-Siegel models are widely used by e.g. practitioners and central banks to estimate current term structures of riskless zero-coupon interest rates, whereas other models such as the extended Vasicek model (a.k.a. the Hull-White model) are popular for pricing interest rate derivatives....... This paper establishes theoretical consistency between these two types of models by showing how to specify the extended Vasicek model such that its implied initial term structure curve precisely matches a given extended Nelson-Siegel specification. That is, we show how to reconcile the two classes of models...
DEFF Research Database (Denmark)
Sadegh, Negar; Stenby, Erling Halfdan; Thomsen, Kaj
2015-01-01
Aqueous MDEA is the most commonly used solvent for H2S removal from natural gas. A reliable thermodynamic model is required for the proper design of natural gas sweetening processes. In this study, a rigorous thermodynamic model is developed to represent properties of the H2S-MDEA-H2O ternary...... system. The Extended UNIQUAC model is used to represent the system behavior. The model is created based on models for the constituent binary subsystems. The developed model provides accurate representation of VLE and heat of absorption for the studied system and subsystem in the temperature range of 0...
Bayesian Network Webserver: a comprehensive tool for biological network modeling.
Ziebarth, Jesse D; Bhattacharya, Anindya; Cui, Yan
2013-11-01
The Bayesian Network Webserver (BNW) is a platform for comprehensive network modeling of systems genetics and other biological datasets. It allows users to quickly and seamlessly upload a dataset, learn the structure of the network model that best explains the data and use the model to understand relationships between network variables. Many datasets, including those used to create genetic network models, contain both discrete (e.g. genotype) and continuous (e.g. gene expression traits) variables, and BNW allows for modeling hybrid datasets. Users of BNW can incorporate prior knowledge during structure learning through an easy-to-use structural constraint interface. After structure learning, users are immediately presented with an interactive network model, which can be used to make testable hypotheses about network relationships. BNW, including a downloadable structure learning package, is available at http://compbio.uthsc.edu/BNW. (The BNW interface for adding structural constraints uses HTML5 features that are not supported by current version of Internet Explorer. We suggest using other browsers (e.g. Google Chrome or Mozilla Firefox) when accessing BNW). ycui2@uthsc.edu. Supplementary data are available at Bioinformatics online.
A Footprint Family extended MRIO model to support Europe's transition to a One Planet Economy.
Galli, Alessandro; Weinzettel, Jan; Cranston, Gemma; Ercin, Ertug
2013-09-01
Currently, the European economy is using nearly three times the ecological assets that are locally available. This situation cannot be sustained indefinitely. Tools are needed that can help reverse the unsustainable trend. In 2010, an EC funded One Planet Economy Network: Europe (OPEN:EU) project was launched to develop the evidence and innovative practical tools that will allow policy-makers and civil society to identify policy interventions to transform Europe into a One Planet Economy, by 2050. Building on the premise that no indicator alone is able to comprehensively monitor (progress towards) sustainability, the project has drawn on the Ecological, Carbon and Water Footprints to define a Footprint Family suite of indicators, to track human pressure on the planet. An environmentally-extended multi-regional input-output (MRIO) model has then been developed to group the Footprint Family under a common framework and combine the indicators in the family with national economic accounts and trade statistics. Although unable to monitor the full spectrum of human pressures, once grouped within the MRIO model, the Footprint Family is able to assess the appropriation of ecological assets, GHG emissions as well as freshwater consumption and pollution associated with consumption of specific products and services within a specified country. Using MRIO models within the context of Footprint analyses also enables the Footprint Family to take into account full production chains with technologies specific to country of origin. Copyright © 2012 Elsevier B.V. All rights reserved.
A Process Model for the Comprehension of Organic Chemistry Notation
Havanki, Katherine L.
This dissertation examines the cognitive processes individuals use when reading organic chemistry equations and factors that affect these processes, namely, visual complexity of chemical equations and participant characteristics (expertise, spatial ability, and working memory capacity). A six stage process model for the comprehension of organic chemistry notation was proposed that accounts for the movement of the eyes across the chemical equation (get next); the search of a chemical structure for key features (search); the encoding of features to create an internal representation (encoding and access lexicon); the assignments of relationships among features in the same molecule (intramolecular relationship) and between molecules (intermolecular relationship); and a check of the internal representation for inconsistencies (reaction wrap-up). Two studies were conducted in this investigation. The first study assessed the validity and ability of the Complexity Rubric for Organic Chemistry Notation to quantify visual complexity of structural formulas. A three-part investigation examined the content of the rubric, its capacity to measure visual complexity, and its ability to predict visual complexity as perceived by novices. The results suggest that the rubric differentiates structural formulas with high visual complexity from those with medium-low visual complexity. A follow-up study examined the effect of prior knowledge on the encoding of organic formulas and suggests that knowledge from domains outside chemistry plays a role in the perceived complexity of structural formulas. In the second study, eye tracking methodology was used to validate the proposed process model for the comprehension of organic chemistry notation and examine factors that affect these processes. Eight instructors and 19 students were eye tracked while reading five high/low complexity pairs of organic chemistry equations for comprehension. The frequency, duration, and sequence of participants
Tzeng, Yuhtsuen; van den Broek, Paul; Kendeou, Panayiota; Lee, Chengyuan
2005-05-01
The complexity of text comprehension demands a computational approach to describe the cognitive processes involved. In this article, we present the computational implementation of the landscape model of reading. This model captures both on-line comprehension processes during reading and the off-line memory representation after reading is completed, incorporating both memory-based and coherence-based mechanisms of comprehension. The overall architecture and specific parameters of the program are described, and a running example is provided. Several studies comparing computational and behavioral data indicate that the implemented model is able to account for cycle-by-cycle comprehension processes and memory for a variety of text types and reading situations.
Audigier, Chloé; Mansi, Tommaso; Delingette, Hervé; Rapaka, Saikiran; Passerini, Tiziano; Mihalef, Viorel; Jolly, Marie-Pierre; Pop, Raoul; Diana, Michele; Soler, Luc; Kamen, Ali; Comaniciu, Dorin; Ayache, Nicholas
2017-09-01
We aim at developing a framework for the validation of a subject-specific multi-physics model of liver tumor radiofrequency ablation (RFA). The RFA computation becomes subject specific after several levels of personalization: geometrical and biophysical (hemodynamics, heat transfer and an extended cellular necrosis model). We present a comprehensive experimental setup combining multimodal, pre- and postoperative anatomical and functional images, as well as the interventional monitoring of intra-operative signals: the temperature and delivered power. To exploit this dataset, an efficient processing pipeline is introduced, which copes with image noise, variable resolution and anisotropy. The validation study includes twelve ablations from five healthy pig livers: a mean point-to-mesh error between predicted and actual ablation extent of 5.3 ± 3.6 mm is achieved. This enables an end-to-end preclinical validation framework that considers the available dataset.
Semi-nonparametric estimation of extended ordered probit models
Mark Stewart
2002-01-01
This paper presents a semi-nonparametric estimator for a series of generalized models that nest the ordered probit model and thereby relax the distributional assumption in that model. It describes a new Stata command for fitting such models and presents an illustration of the approach. Copyright 2004 by StataCorp LP.
A comprehensive approach to age-dependent dosimetric modeling
Energy Technology Data Exchange (ETDEWEB)
Leggett, R.W.; Cristy, M.; Eckerman, K.F.
1986-01-01
In the absence of age-specific biokinetic models, current retention models of the International Commission on Radiological Protection (ICRP) frequently are used as a point of departure for evaluation of exposures to the general population. These models were designed and intended for estimation of long-term integrated doses to the adult worker. Their format and empirical basis preclude incorporation of much valuable physiological information and physiologically reasonable assumptions that could be used in characterizing the age-specific behavior of radioelements in humans. In this paper we discuss a comprehensive approach to age-dependent dosimetric modeling in which consideration is given not only to changes with age in masses and relative geometries of body organs and tissues but also to best available physiological and radiobiological information relating to the age-specific biobehavior of radionuclides. This approach is useful in obtaining more accurate estimates of long-term dose commitments as a function of age at intake, but it may be particularly valuable in establishing more accurate estimates of dose rate as a function of age. Age-specific dose rates are needed for a proper analysis of the potential effects on estimates or risk of elevated dose rates per unit intake in certain stages of life, elevated response per unit dose received during some stages of life, and age-specific non-radiogenic competing risks.
A short mnemonic to support the comprehensive geriatric assessment model.
Han, Brenda; Grant, Cristin
2016-10-06
With an increasing number of older people using emergency services, researchers have raised concerns about the quality of care in an environment that is not designed to address older patients' specific needs and conditions. The comprehensive geriatric assessment (CGA) model was developed to address these issues, and to optimise healthcare delivery to older adults. This article introduces a complementary mnemonic, FRAIL, that refers to important elements of health information to consider before initiating care for older patients - falls/functional decline, reactions, altered mental status, illnesses, and living situation. It is not intended to replace the CGA, but can help to quickly identify high-risk older patients who warrant a more in-depth clinical assessment with CGA.
Numerical modeling of an estuary: A comprehensive skill assessment
Warner, J.C.; Geyer, W.R.; Lerczak, J.A.
2005-01-01
Numerical simulations of the Hudson River estuary using a terrain-following, three-dimensional model (Regional Ocean Modeling System (ROMS)) are compared with an extensive set of time series and spatially resolved measurements over a 43 day period with large variations in tidal forcing and river discharge. The model is particularly effective at reproducing the observed temporal variations in both the salinity and current structure, including tidal, spring neap, and river discharge-induced variability. Large observed variations in stratification between neap and spring tides are captured qualitatively and quantitatively by the model. The observed structure and variations of the longitudinal salinity gradient are also well reproduced. The most notable discrepancy between the model and the data is in the vertical salinity structure. While the surface-to-bottom salinity difference is well reproduced, the stratification in the model tends to extend all the way to the water surface, whereas the observations indicate a distinct pycnocline and a surface mixed layer. Because the southern boundary coindition is located near the mouth the estuary, the salinity within the domain is particularly sensitive to the specification of salinity at the boundary. A boundary condition for the horizontal salinity gradient, based on the local value of salinity, is developed to incorporate physical processes beyond the open boundary not resolved by the model. Model results are sensitive to the specification of the bottom roughness length and vertical stability functions, insofar as they influence the intensity of vertical mixing. The results only varied slightly between different turbulence closure methods of k-??, k-??, and k-kl. Copyright 2005 by the American Geophysical Union.
Faraway, Julian J
2005-01-01
Linear models are central to the practice of statistics and form the foundation of a vast range of statistical methodologies. Julian J. Faraway''s critically acclaimed Linear Models with R examined regression and analysis of variance, demonstrated the different methods available, and showed in which situations each one applies. Following in those footsteps, Extending the Linear Model with R surveys the techniques that grow from the regression model, presenting three extensions to that framework: generalized linear models (GLMs), mixed effect models, and nonparametric regression models. The author''s treatment is thoroughly modern and covers topics that include GLM diagnostics, generalized linear mixed models, trees, and even the use of neural networks in statistics. To demonstrate the interplay of theory and practice, throughout the book the author weaves the use of the R software environment to analyze the data of real examples, providing all of the R commands necessary to reproduce the analyses. All of the ...
Assessing the Comprehensive Seismic Earth Model using normal mode data
Koelemeijer, Paula; Afanasiev, Michael; Fichtner, Andreas; Gokhberg, Alexey
2016-04-01
Advances in computational resources and numerical methods allow the simulation of realistic seismic wave propagation through complex media, while ensuring that the complete wave field is correctly represented in synthetic seismograms. This full waveform inversion is widely applied on regional and continental scales, where particularly dense data sampled can be achieved leading to an increased resolution in the obtained model images. On a global scale, however, full waveform tomography is still and will continue to be limited to longer length scales due to the large computational costs. Normal mode tomography provides an alternative fast full waveform approach for imaging seismic structures in a global way. Normal modes are not limited by the poor station-earthquake distribution and provide sensitivity to density structure. Using normal modes, a more robust long wavelength background model can be obtained, leading to more accurate absolute velocity models for tectonic and mineral physics interpretations. In addition, it is vital to combine all seismic data types across accessible periods to obtain a more complete, consistent and interpretable image of the Earth's interior. Here, we aim to combine the globally sensitive long period normal modes with shorter period full waveform modelling within the multi-scale framework of the Comprehensive Seismic Earth Model (CSEM). The multi-scale inversion framework of the CSEM allows exploitation of the full waveform capacity on both sides of the seismic spectrum. As the CSEM includes high-resolution subregions with velocity variations at much shorter wavelengths than normal modes could constrain, the question arises whether these small-scale variations are noticeable in normal mode data, and which modes respond in particular. We report here on experiments in which we address these questions. We separately investigate the effects of small-scale variations in shear-wave velocity and compressional wave velocity compared to the
Towards a computational model of actor-based language comprehension.
Alday, Phillip M; Schlesewsky, Matthias; Bornkessel-Schlesewsky, Ina
2014-01-01
Neurophysiological data from a range of typologically diverse languages provide evidence for a cross-linguistically valid, actor-based strategy of understanding sentence-level meaning. This strategy seeks to identify the participant primarily responsible for the state of affairs (the actor) as quickly and unambiguously as possible, thus resulting in competition for the actor role when there are multiple candidates. Due to its applicability across languages with vastly different characteristics, we have proposed that the actor strategy may derive from more basic cognitive or neurobiological organizational principles, though it is also shaped by distributional properties of the linguistic input (e.g. the morphosyntactic coding strategies for actors in a given language). Here, we describe an initial computational model of the actor strategy and how it interacts with language-specific properties. Specifically, we contrast two distance metrics derived from the output of the computational model (one weighted and one unweighted) as potential measures of the degree of competition for actorhood by testing how well they predict modulations of electrophysiological activity engendered by language processing. To this end, we present an EEG study on word order processing in German and use linear mixed-effects models to assess the effect of the various distance metrics. Our results show that a weighted metric, which takes into account the weighting of an actor-identifying feature in the language under consideration outperforms an unweighted distance measure. We conclude that actor competition effects cannot be reduced to feature overlap between multiple sentence participants and thereby to the notion of similarity-based interference, which is prominent in current memory-based models of language processing. Finally, we argue that, in addition to illuminating the underlying neurocognitive mechanisms of actor competition, the present model can form the basis for a more comprehensive
Extending Isobar Model for Kaon Photoproduction up to 16 GeV
Mart, T
2003-01-01
We extend the isobar model for kaon photoproduction to consider higher energy data by combining the model with a Regge approach. The extended model works nicely between threshold and 16 GeV. It is shown that model with crossing symmetric Born terms leads to a better description of experimental data. We use the model to calculate contributions of kaon channels to the Gerasimov-Drell-Hearn sum rule up to 16 GeV.
Extending enterprise architecture modelling with business goals and requirements
Engelsman, W.; Quartel, Dick; Jonkers, Henk; van Sinderen, Marten J.
The methods for enterprise architecture (EA), such as The Open Group Architecture Framework, acknowledge the importance of requirements modelling in the development of EAs. Modelling support is needed to specify, document, communicate and reason about goals and requirements. The current modelling
Modeling the effect of comprehensive interventions on Ebola virus transmission
Shen, Mingwang; Xiao, Yanni; Rong, Libin
2015-10-01
Since the re-emergence of Ebola in West Africa in 2014, comprehensive and stringent interventions have been implemented to decelerate the spread of the disease. The effectiveness of interventions still remains unclear. In this paper, we develop an epidemiological model that includes various controlling measures to systematically evaluate their effects on the disease transmission dynamics. By fitting the model to reported cumulative cases and deaths in Guinea, Sierra Leone and Liberia until March 22, 2015, we estimate the basic reproduction number in these countries as 1.2552, 1.6093 and 1.7994, respectively. Model analysis shows that there exists a threshold of the effectiveness of isolation, below which increasing the fraction of latent individuals diagnosed prior to symptoms onset or shortening the duration between symptoms onset and isolation may lead to more Ebola infection. This challenges an existing view. Media coverage plays a substantial role in reducing the final epidemic size. The response to reported cumulative infected cases and deaths may have a different effect on the epidemic spread in different countries. Among all the interventions, we find that shortening the duration between death and burial and improving the effectiveness of isolation are two effective interventions for controlling the outbreak of Ebola virus infection.
A cosmological dust model with extended f({chi}) gravity
Energy Technology Data Exchange (ETDEWEB)
Carranza, D.A.; Mendoza, S.; Torres, L.A. [Universidad Nacional Autonoma de Mexico, Instituto de Astronomia, AP 70-264, Distrito Federal (Mexico)
2013-01-15
Introducing a fundamental constant of nature with dimensions of acceleration into the theory of gravity makes it possible to extend gravity in a very consistent manner. At the non-relativistic level a MOND-like theory with a modification in the force sector is obtained, which is the limit of a very general metric relativistic theory of gravity. Since the mass and length scales involved in the dynamics of the whole universe require small accelerations of the order of Milgrom's acceleration constant a{sub 0}, it turns out that the relativistic theory of gravity can be used to explain the expansion of the universe. In this work it is explained how to use that relativistic theory of gravity in such a way that the overall large-scale dynamics of the universe can be treated in a pure metric approach without the need to introduce dark matter and/or dark energy components. (orig.)
Extending enterprise architecture modelling with business goals and requirements
Engelsman, Wilco; Quartel, Dick; Jonkers, Henk; van Sinderen, Marten
2011-02-01
The methods for enterprise architecture (EA), such as The Open Group Architecture Framework, acknowledge the importance of requirements modelling in the development of EAs. Modelling support is needed to specify, document, communicate and reason about goals and requirements. The current modelling techniques for EA focus on the products, services, processes and applications of an enterprise. In addition, techniques may be provided to describe structured requirements lists and use cases. Little support is available however for modelling the underlying motivation of EAs in terms of stakeholder concerns and the high-level goals that address these concerns. This article describes a language that supports the modelling of this motivation. The definition of the language is based on existing work on high-level goal and requirements modelling and is aligned with an existing standard for enterprise modelling: the ArchiMate language. Furthermore, the article illustrates how EA can benefit from analysis techniques from the requirements engineering domain.
Faculty's Acceptance of Computer Based Technology: Cross-Validation of an Extended Model
Ahmad, Tunku Badariah Tunku; Madarsha, Kamal Basha; Zainuddin, Ahmad Marzuki; Ismail, Nik Ahmad Hisham; Nordin, Mohamad Sahari
2010-01-01
The first aim of the present study is to validate an extended technology acceptance model (TAME) on the data derived from the faculty members of a university in an ongoing, computer mediated work setting. The study extended the original TAM model by including an intrinsic motivation component--computer self efficacy. In so doing, the study…
Students Working Online for Group Projects: A Test of an Extended Theory of Planned Behaviour Model
Cheng, Eddie W. L.
2017-01-01
This study examined an extended theory of planned behaviour (TPB) model that specified factors affecting students' intentions to collaborate online for group work. Past behaviour, past experience and actual behavioural control were incorporated in the extended TPB model. The mediating roles of attitudes, subjective norms and perceived behavioural…
Extending Growth Mixture Models Using Continuous Non-Elliptical Distributions
Wei, Yuhong; Tang, Yang; Shireman, Emilie; McNicholas, Paul D.; Steinley, Douglas L.
2017-01-01
Growth mixture models (GMMs) incorporate both conventional random effects growth modeling and latent trajectory classes as in finite mixture modeling; therefore, they offer a way to handle the unobserved heterogeneity between subjects in their development. GMMs with Gaussian random effects dominate the literature. When the data are asymmetric and/or have heavier tails, more than one latent class is required to capture the observed variable distribution. Therefore, a GMM with continuous non-el...
Symbolic LTL Compilation for Model Checking: Extended Abstract
Rozier, Kristin Y.; Vardi, Moshe Y.
2007-01-01
In Linear Temporal Logic (LTL) model checking, we check LTL formulas representing desired behaviors against a formal model of the system designed to exhibit these behaviors. To accomplish this task, the LTL formulas must be translated into automata [21]. We focus on LTL compilation by investigating LTL satisfiability checking via a reduction to model checking. Having shown that symbolic LTL compilation algorithms are superior to explicit automata construction algorithms for this task [16], we concentrate here on seeking a better symbolic algorithm.We present experimental data comparing algorithmic variations such as normal forms, encoding methods, and variable ordering and examine their effects on performance metrics including processing time and scalability. Safety critical systems, such as air traffic control, life support systems, hazardous environment controls, and automotive control systems, pervade our daily lives, yet testing and simulation alone cannot adequately verify their reliability [3]. Model checking is a promising approach to formal verification for safety critical systems which involves creating a formal mathematical model of the system and translating desired safety properties into a formal specification for this model. The complement of the specification is then checked against the system model. When the model does not satisfy the specification, model-checking tools accompany this negative answer with a counterexample, which points to an inconsistency between the system and the desired behaviors and aids debugging efforts.
Extending a configuration model to find communities in complex networks
Jin, Di; He, Dongxiao; Hu, Qinghua; Baquero, Carlos; Yang, Bo
2013-09-01
Discovery of communities in complex networks is a fundamental data analysis task in various domains. Generative models are a promising class of techniques for identifying modular properties from networks, which has been actively discussed recently. However, most of them cannot preserve the degree sequence of networks, which will distort the community detection results. Rather than using a blockmodel as most current works do, here we generalize a configuration model, namely, a null model of modularity, to solve this problem. Towards decomposing and combining sub-graphs according to the soft community memberships, our model incorporates the ability to describe community structures, something the original model does not have. Also, it has the property, as with the original model, that it fixes the expected degree sequence to be the same as that of the observed network. We combine both the community property and degree sequence preserving into a single unified model, which gives better community results compared with other models. Thereafter, we learn the model using a technique of nonnegative matrix factorization and determine the number of communities by applying consensus clustering. We test this approach both on synthetic benchmarks and on real-world networks, and compare it with two similar methods. The experimental results demonstrate the superior performance of our method over competing methods in detecting both disjoint and overlapping communities.
An application of the Rasch model to reading comprehension measurement
National Research Council Canada - National Science Library
Santos, Sandra; Cadime, Irene; Viana, Fernanda Leopoldina; Prieto, Gerardo; Chaves-Sousa, Séli; Spinillo, Alina Galvão; Ribeiro, Iolanda
2016-01-01
An effective reading comprehension measurement demands robust psychometric tools that allow teachers and researchers to evaluate the educational practices and track changes in students’ performance...
Meyler, Ann; Keller, Timothy A; Cherkassky, Vladimir L; Gabrieli, John D E; Just, Marcel Adam
2008-08-01
This study used fMRI to longitudinally assess the impact of intensive remedial instruction on cortical activation among 5th grade poor readers during a sentence comprehension task. The children were tested at three time points: prior to remediation, after 100 h of intensive instruction, and 1 year after the instruction had ended. Changes in brain activation were also measured among 5th grade good readers at the same time points for comparison. The central finding was that prior to instruction, the poor readers had significantly less activation than good readers bilaterally in the parietal cortex. Immediately after instruction, poor readers made substantial gains in reading ability, and demonstrated significantly increased activation in the left angular gyrus and the left superior parietal lobule. Activation in these regions continued to increase among poor readers 1 year post-remediation, resulting in a normalization of the activation. These results are interpreted as reflecting changes in the processes involved in word-level and sentence-level assembly. Areas of overactivation were also found among poor readers in the medial frontal cortex, possibly indicating a more effortful and attentive guided reading strategy.
Hazard identification by extended multilevel flow modelling with function roles
DEFF Research Database (Denmark)
Wu, Jing; Zhang, Laibin; Jørgensen, Sten Bay
2014-01-01
HAZOP studies are widely accepted in chemical and petroleum industries as the method for conducting process hazard analysis related to design, maintenance and operation of th e systems. In this paper, a HAZOP reasoning method based on function-oriented modelling, multilevel flow modelling (MFM...
Hyperstate matrix models : extending demographic state spaces to higher dimensions
Roth, G.; Caswell, H.
2016-01-01
1. Demographic models describe population dynamics in terms of the movement of individuals among states (e.g. size, age, developmental stage, parity, frailty, physiological condition). Matrix population models originally classified individuals by a single characteristic. This was enlarged to two
Statistical model of stress corrosion cracking based on extended ...
Indian Academy of Sciences (India)
2013-12-01
Dec 1, 2013 ... Abstract. The mechanism of stress corrosion cracking (SCC) has been discussed for decades. Here I propose a model of SCC reflecting the feature of fracture in brittle manner based on the vari- ational principle under approximately supposed thermal equilibrium. In that model the functionals are expressed ...
Generative probabilistic models extend the scope of inferential structure determination
DEFF Research Database (Denmark)
Olsson, Simon; Boomsma, Wouter; Frellsen, Jes
2011-01-01
demonstrate that the use of generative probabilistic models instead of physical forcefields in the Bayesian formalism is not only conceptually attractive, but also improves precision and efficiency. Our results open new vistas for the use of sophisticated probabilistic models of biomolecular structure...
Comprehensive model for disruption erosion in a reactor environment
Energy Technology Data Exchange (ETDEWEB)
Hassanein, A. [Argonne National Lab., IL (United States); Konkashbaev, I. [Troitsk Institute for Innovation, Moscow Region (Russia)
1994-08-01
Disruptions in tokamak reactors are still of serious concern and present a potential obstacle for successful operation and reliable design. Erosion of plasma-facing materials due to thermal energy dump during a disruption can severely limit the lifetime of these components, therefore diminishes the economic feasibility of the reactor. A comprehensive disruption erosion model which takes into account the interplay of all physical processes during plasma-material interaction has been developed. The initial burst of energy delivered to facing-material surfaces from direct impact of plasma particles causes sudden ablation of these materials. As a result, a vapor cloud is formed in front of the incident plasma particles. Shortly thereafter, the plasma particles are stopped in the vapor cloud, heating and ionizing it. The energy transmitted to the material surfaces is then dominated by photon radiation. It is the dynamics and the evolution of this vapor cloud that finally determines the net erosion rate and, consequently, the component lifetime. The model integrates with sufficient detail and in a self-consistent way, material thermal evolution response, plasma-vapor interaction physics, vapor hydrodynamics and radiation transport in order to realistically simulate the effects of a plasma disruption on plasma-facing components. Candidate materials such as beryllium and carbon have.been analyzed. The dependence of the net erosion rate on disruption physics and various parameters was analyzed and is discussed.
Extended Poisson process modelling and analysis of grouped binary data.
Faddy, Malcolm J; Smith, David M
2012-05-01
A simple extension of the Poisson process results in binomially distributed counts of events in a time interval. A further extension generalises this to probability distributions under- or over-dispersed relative to the binomial distribution. Substantial levels of under-dispersion are possible with this modelling, but only modest levels of over-dispersion - up to Poisson-like variation. Although simple analytical expressions for the moments of these probability distributions are not available, approximate expressions for the mean and variance are derived, and used to re-parameterise the models. The modelling is applied in the analysis of two published data sets, one showing under-dispersion and the other over-dispersion. More appropriate assessment of the precision of estimated parameters and reliable model checking diagnostics follow from this more general modelling of these data sets. © 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
Towards a comprehensive developmental model of pathological gambling.
Blanco, Carlos; Hanania, Joan; Petry, Nancy M; Wall, Melanie M; Wang, Shuai; Jin, Chelsea J; Kendler, Kenneth S
2015-08-01
To develop a comprehensive etiological model of pathological gambling (PG) for men and women based on Kendler's development model for major depression, which groups 22 risk factors into five developmental tiers (childhood, early adolescence, late adolescence, adulthood, last year). We hypothesized that: (1) all risk factors would be associated significantly with PG; (2) the effect of risk factors in earlier developmental tiers would be accounted for by later tiers; and (3) there would be few gender differences. Separate models were built for life-time gambling and for 12-month PG among those with life-time gambling. Data drawn from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) in the United States. Respondents to NESARC wave 1 (n = 43 093). Odds ratios (OR) and adjusted OR (AOR) were used to determine the risk factors in multiple models. After mutually adjusting for other risk factors, family history of substance use disorders (SUD) or depression, impulsivity, childhood-onset anxiety, number of Axis I and II disorders, history of SUD, nicotine dependence, social deviance in adulthood, and past-year history of SUD, nicotine dependence and independent stressful life events predicted life-time gambling. Past history of PG, number of personality disorders and past year nicotine dependence were associated significantly with 12-month PG (all P gambling. Life-time history of gambling and 12-month pathological gambling appear to be determined by risk factors in several developmental levels, with the effect of earlier development tiers accounted for by later ones. © 2015 Society for the Study of Addiction.
Extended Rasch Modeling: The eRm Package for the Application of IRT Models in R
Directory of Open Access Journals (Sweden)
Patrick Mair
2007-02-01
Full Text Available Item response theory models (IRT are increasingly becoming established in social science research, particularly in the analysis of performance or attitudinal data in psychology, education, medicine, marketing and other fields where testing is relevant. We propose the R package eRm (extended Rasch modeling for computing Rasch models and several extensions. A main characteristic of some IRT models, the Rasch model being the most prominent, concerns the separation of two kinds of parameters, one that describes qualities of the subject under investigation, and the other relates to qualities of the situation under which the response of a subject is observed. Using conditional maximum likelihood (CML estimation both types of parameters may be estimated independently from each other. IRT models are well suited to cope with dichotomous and polytomous responses, where the response categories may be unordered as well as ordered. The incorporation of linear structures allows for modeling the effects of covariates and enables the analysis of repeated categorical measurements. The eRm package fits the following models: the Rasch model, the rating scale model (RSM, and the partial credit model (PCM as well as linear reparameterizations through covariate structures like the linear logistic test model (LLTM, the linear rating scale model (LRSM, and the linear partial credit model (LPCM. We use an unitary, efficient CML approach to estimate the item parameters and their standard errors. Graphical and numeric tools for assessing goodness-of-fit are provided.
CM5: A pre-Swarm magnetic field model based upon the comprehensive modeling approach
DEFF Research Database (Denmark)
Sabaka, T.; Olsen, Nils; Tyler, Robert
2014-01-01
We have developed a model based upon the very successful Comprehensive Modeling (CM) approach using recent CHAMP, Ørsted, SAC-C and observatory hourly-means data from September 2000 to the end of 2013. This CM, called CM5, was derived from the algorithm that will provide a consistent line of Leve...
COMPREHENSIVE PBPK MODELING APPROACH USING THE EXPOSURE RELATED DOSE ESTIMATING MODEL (ERDEM)
ERDEM, a complex PBPK modeling system, is the result of the implementation of a comprehensive PBPK modeling approach. ERDEM provides a scalable and user-friendly environment that enables researchers to focus on data input values rather than writing program code. It efficiently ...
Standard State Space Models of Unawareness (Extended Abstract
Directory of Open Access Journals (Sweden)
Peter Fritz
2016-06-01
Full Text Available The impossibility theorem of Dekel, Lipman and Rustichini has been thought to demonstrate that standard state-space models cannot be used to represent unawareness. We first show that Dekel, Lipman and Rustichini do not establish this claim. We then distinguish three notions of awareness, and argue that although one of them may not be adequately modeled using standard state spaces, there is no reason to think that standard state spaces cannot provide models of the other two notions. In fact, standard space models of these forms of awareness are attractively simple. They allow us to prove completeness and decidability results with ease, to carry over standard techniques from decision theory, and to add propositional quantifiers straightforwardly.
Modern elementary particle physics explaining and extending the standard model
Kane, Gordon
2017-01-01
This book is written for students and scientists wanting to learn about the Standard Model of particle physics. Only an introductory course knowledge about quantum theory is needed. The text provides a pedagogical description of the theory, and incorporates the recent Higgs boson and top quark discoveries. With its clear and engaging style, this new edition retains its essential simplicity. Long and detailed calculations are replaced by simple approximate ones. It includes introductions to accelerators, colliders, and detectors, and several main experimental tests of the Standard Model are explained. Descriptions of some well-motivated extensions of the Standard Model prepare the reader for new developments. It emphasizes the concepts of gauge theories and Higgs physics, electroweak unification and symmetry breaking, and how force strengths vary with energy, providing a solid foundation for those working in the field, and for those who simply want to learn about the Standard Model.
Comprehensible knowledge model creation for cancer treatment decision making.
Afzal, Muhammad; Hussain, Maqbool; Ali Khan, Wajahat; Ali, Taqdir; Lee, Sungyoung; Huh, Eui-Nam; Farooq Ahmad, Hafiz; Jamshed, Arif; Iqbal, Hassan; Irfan, Muhammad; Abbas Hydari, Manzar
2017-03-01
A wealth of clinical data exists in clinical documents in the form of electronic health records (EHRs). This data can be used for developing knowledge-based recommendation systems that can assist clinicians in clinical decision making and education. One of the big hurdles in developing such systems is the lack of automated mechanisms for knowledge acquisition to enable and educate clinicians in informed decision making. An automated knowledge acquisition methodology with a comprehensible knowledge model for cancer treatment (CKM-CT) is proposed. With the CKM-CT, clinical data are acquired automatically from documents. Quality of data is ensured by correcting errors and transforming various formats into a standard data format. Data preprocessing involves dimensionality reduction and missing value imputation. Predictive algorithm selection is performed on the basis of the ranking score of the weighted sum model. The knowledge builder prepares knowledge for knowledge-based services: clinical decisions and education support. Data is acquired from 13,788 head and neck cancer (HNC) documents for 3447 patients, including 1526 patients of the oral cavity site. In the data quality task, 160 staging values are corrected. In the preprocessing task, 20 attributes and 106 records are eliminated from the dataset. The Classification and Regression Trees (CRT) algorithm is selected and provides 69.0% classification accuracy in predicting HNC treatment plans, consisting of 11 decision paths that yield 11 decision rules. Our proposed methodology, CKM-CT, is helpful to find hidden knowledge in clinical documents. In CKM-CT, the prediction models are developed to assist and educate clinicians for informed decision making. The proposed methodology is generalizable to apply to data of other domains such as breast cancer with a similar objective to assist clinicians in decision making and education. Copyright © 2017 Elsevier Ltd. All rights reserved.
A Proof Theory for Model Checking: An Extended Abstract
Directory of Open Access Journals (Sweden)
Quentin Heath
2017-01-01
Full Text Available While model checking has often been considered as a practical alternative to building formal proofs, we argue here that the theory of sequent calculus proofs can be used to provide an appealing foundation for model checking. Since the emphasis of model checking is on establishing the truth of a property in a model, we rely on the proof theoretic notion of additive inference rules, since such rules allow provability to directly describe truth conditions. Unfortunately, the additive treatment of quantifiers requires inference rules to have infinite sets of premises and the additive treatment of model descriptions provides no natural notion of state exploration. By employing a focused proof system, it is possible to construct large scale, synthetic rules that also qualify as additive but contain elements of multiplicative inference. These additive synthetic rules—essentially rules built from the description of a model—allow a direct treatment of state exploration. This proof theoretic framework provides a natural treatment of reachability and non-reachability problems, as well as tabled deduction, bisimulation, and winning strategies.
Extending the LCDM model through shear-free anisotropies
Pereira, Thiago S
2016-01-01
If the spacetime metric has anisotropic spatial curvature, one can afford to expand the universe isotropically, provided that the energy-momentum tensor satisfy a certain con- straint. This leads to the so-called shear-free metrics, which have the interesting property of violating the cosmological principle while still preserving the isotropy of the cosmic mi- crowave background (CMB) radiation. In this work we show that shear-free cosmologies correspond to an attractor solution in the space of models with anisotropic spatial curva- ture. Through a rigorous definition of linear perturbation theory in these spacetimes, we show that shear-free models represent a viable alternative to describe the large-scale evo- lution of the universe, leading, in particular, to a kinematically equivalent Sachs-Wolfe effect. Alternatively, we discuss some specific signatures that shear-free models would imprint on the temperature spectrum of CMB.
Extending the dimensionality of flatland with attribute view probabilistic models
Neufeld, Eric; Bickis, Mikelis; Grant, Kevin
2008-01-01
In much of Bertin's Semiology of Graphics, marks representing individuals are arranged on paper according to their various attributes (components). Paper and computer monitors can conveniently map two attributes to width and height, and can map other attributes into nonspatial dimensions such as texture, or colour. Good visualizations exploit the human perceptual apparatus so that key relationships are quickly detected as interesting patterns. Graphical models take a somewhat dual approach with respect to the original information. Components, rather than individuals, are represented as marks. Links between marks represent conceptually simple, easily computable, and typically probabilistic relationships of possibly varying strength, and the viewer studies the diagram to discover deeper relationships. Although visually annotated graphical models have been around for almost a century, they have not been widely used. We argue that they have the potential to represent multivariate data as generically as pie charts represent univariate data. The present work suggests a semiology for graphical models, and discusses the consequences for information visualization.
Elementary particles, dark matter candidate and new extended standard model
Hwang, Jaekwang
2017-01-01
Elementary particle decays and reactions are discussed in terms of the three-dimensional quantized space model beyond the standard model. Three generations of the leptons and quarks correspond to the lepton charges. Three heavy leptons and three heavy quarks are introduced. And the bastons (new particles) are proposed as the possible candidate of the dark matters. Dark matter force, weak force and strong force are explained consistently. Possible rest masses of the new particles are, tentatively, proposed for the experimental searches. For more details, see the conference paper at https://www.researchgate.net/publication/308723916.
Extending MBI Model using ITIL and COBIT Processes
Directory of Open Access Journals (Sweden)
Sona Karkoskova
2015-10-01
Full Text Available Most organizations today operate in a highly complex and competitive business environment and need to be able to react to rapidly changing market conditions. IT management frameworks are widely used to provide effective support for business objectives through aligning IT with business and optimizing the use of IT resources. In this paper we analyze three IT management frameworks (ITIL, COBIT and MBI with the objective to identify the relationships between these frameworks, and mapping ITIL and COBIT processes to MBI tasks. As a result of this analysis we propose extensions to the MBI model to incorporate IT Performance Management and a Capability Maturity Model.
Experimental validation of extended NO and soot model for advanced HD diesel engine combustion
Seykens, X.L.J.; Baert, R.S.G.; Somers, L.M.T.; Willems, F.P.T.
2009-01-01
A computationally efficient engine model is developed based on an extended NO emission model and state-of-the-art soot model. The model predicts exhaust NO and soot emission for both conventional and advanced, high-EGR (up to 50%), heavy-duty DI diesel combustion. Modeling activities have aimed at
Charged excitons in doped extended Hubbard model systems
van den Brink, J.; Eder, R; Sawatzky, G.A
1997-01-01
We show that the charge transfer excitons in a Hubbard model system including nearest-neighbor Coulomb interactions effectively attain some charge in doped systems and become visible in photoelectron and inverse photoelectron spectroscopies. This shows that the description of a doped system by an
An extended topological model for binary phosphate glasses
DEFF Research Database (Denmark)
Hermansen, Christian; Rodrigues, B.P.; Wondraczek, L.
2014-01-01
the model reduces to classical constraint counting. The constraints on the modifying cations are linear constraints to first neighbor NBOs, and all angular constraints are broken as expected for ionic bonding. For small modifying cations, such as Li+, the linear constraints are almost fully intact...
Extended Langmuir model fitting to the filter column adsorption data ...
African Journals Online (AJOL)
Leachate samples collected at different depths of WQD column were analyzed for concentrations of zinc and copper ions using atomic absorption spectrometer. The removal efficiency was around 94% and 92% for zinc and copper respectively using column depth of 1 M at a flow rate of 12 ml/min. The adsorption model ...
Searches for Neutral Higgs Bosons in Extended Models
Abdallah, J; Adam, W; Adzic, P; Albrecht, T; Alderweireld, T; Alemany-Fernandez, R; Allmendinger, T; Allport, P P; Amaldi, Ugo; Amapane, N; Amato, S; Anashkin, E; Andreazza, A; Andringa, S; Anjos, N; Antilogus, P; Apel, W D; Arnoud, Y; Ask, S; Åsman, B; Augustin, J E; Augustinus, A; Baillon, Paul; Ballestrero, A; Bambade, P; Barbier, R; Bardin, Dimitri Yuri; Barker, G J; Baroncelli, A; Battaglia, Marco; Baubillier, M; Becks, K H; Begalli, M; Behrmann, A; Ben-Haim, E; Benekos, N C; Benvenuti, Alberto C; Bérat, C; Berggren, M; Berntzon, L; Bertrand, D; Besançon, M; Besson, N; Bloch, D; Blom, M; Bluj, M; Bonesini, M; Boonekamp, M; Booth, P S L; Borisov, G; Botner, O; Bouquet, B; Bowcock, T J V; Boyko, I; Bracko, M; Brenner, R; Brodet, E; Brückman, P; Brunet, J M; Bugge, L; Buschmann, P; Calvi, M; Camporesi, T; Canale, V; Carena, F; Castro, N; Cavallo, F R; Chapkin, M M; Charpentier, P; Checchia, P; Chierici, R; Shlyapnikov, P; Chudoba, J; Chung, S U; Cieslik, K; Collins, P; Contri, R; Cosme, G; Cossutti, F; Costa, M J; Crennell, D J; Cuevas-Maestro, J; D'Hondt, J; Dalmau, J; Da Silva, T; Da Silva, W; Della Ricca, G; De Angelis, A; de Boer, Wim; De Clercq, C; De Lotto, B; De Maria, N; De Min, A; De Paula, L S; Di Ciaccio, L; Di Simone, A; Doroba, K; Drees, J; Dris, M; Eigen, G; Ekelöf, T J C; Ellert, M; Elsing, M; Espirito-Santo, M C; Fanourakis, G K; Fassouliotis, D; Feindt, M; Fernández, J; Ferrer, A; Ferro, F; Flagmeyer, U; Föth, H; Fokitis, E; Fulda-Quenzer, F; Fuster, J A; Gandelman, M; García, C; Gavillet, P; Gazis, E N; Gokieli, R; Golob, B; Gómez-Ceballos, G; Gonçalves, P; Graziani, E; Grosdidier, G; Grzelak, K; Guy, J; Haag, C; Hallgren, A; Hamacher, K; Hamilton, K; Haug, S; Hauler, F; Hedberg, V; Hennecke, M; Herr, H; Hoffman, J; Holmgren, S O; Holt, P J; Houlden, M A; Hultqvist, K; Jackson, J N; Jarlskog, G; Jarry, P; Jeans, D; Johansson, E K; Johansson, P D; Jonsson, P; Joram, C; Jungermann, L; Kapusta, F; Katsanevas, S; Katsoufis, E C; Kernel, G; Kersevan, B P; Kerzel, U; Kiiskinen, A P; King, B T; Kjaer, N J; Kluit, P; Kokkinias, P; Kourkoumelis, C; Kuznetsov, O; Krumshtein, Z; Kucharczyk, M; Lamsa, J; Leder, G; Ledroit, F; Leinonen, L; Leitner, R; Lemonne, J; Lepeltier, V; Lesiak, T; Liebig, W; Liko, D; Lipniacka, A; Lopes, J H; López, J M; Loukas, D; Lutz, P; Lyons, L; MacNaughton, J; Malek, A; Maltezos, S; Mandl, F; Marco, J; Marco, R; Maréchal, B; Margoni, M; Marin, J C; Mariotti, C; Markou, A; Martínez-Rivero, C; Masik, J; Mastroyiannopoulos, N; Matorras, F; Matteuzzi, C; Mazzucato, F; Mazzucato, M; McNulty, R; Meroni, C; Migliore, E; Mitaroff, W A; Mjörnmark, U; Moa, T; Moch, M; Mönig, K; Monge, R; Montenegro, J; Moraes, D; Moreno, S; Morettini, P; Müller, U; Münich, K; Mulders, M; Mundim, L; Murray, W; Muryn, B; Myatt, G; Myklebust, T; Nassiakou, M; Navarria, Francesco Luigi; Nawrocki, K; Nicolaidou, R; Nikolenko, M; Oblakowska-Mucha, A; Obraztsov, V F; Olshevskii, A G; Onofre, A; Orava, R; Österberg, K; Ouraou, A; Oyanguren, A; Paganoni, M; Paiano, S; Palacios, J P; Palka, H; Papadopoulou, T D; Pape, L; Parkes, C; Parodi, F; Parzefall, U; Passeri, A; Passon, O; Peralta, L; Perepelitsa, V F; Perrotta, A; Petrolini, A; Piedra, J; Pieri, L; Pierre, F; Pimenta, M; Piotto, E; Podobnik, T; Poireau, V; Pol, M E; Polok, G; Pozdnyakov, V; Pukhaeva, N; Pullia, A; Rames, J; Read, A; Rebecchi, P; Rehn, J; Reid, D; Reinhardt, R; Renton, P B; Richard, F; Rídky, J; Rivero, M; Rodríguez, D; Romero, A; Ronchese, P; Roudeau, P; Rovelli, T; Ruhlmann-Kleider, V; Ryabtchikov, D; Sadovskii, A; Salmi, L; Salt, J; Sander, C; Savoy-Navarro, A; Schwickerath, U; Segar, A; Sekulin, R L; Siebel, M; Sissakian, A N; Smadja, G; Smirnova, O G; Sokolov, A; Sopczak, A; Sosnowski, R; Spassoff, Tz; Stanitzki, M; Stocchi, A; Strauss, J; Stugu, B; Szczekowski, M; Szeptycka, M; Szumlak, T; Tabarelli de Fatis, T; Taffard, A C; Tegenfeldt, F; Timmermans, J; Tkatchev, L G; Tobin, M; Todorovova, S; Tomé, B; Tonazzo, A; Tortosa, P; Travnicek, P; Treille, D; Tristram, G; Trochimczuk, M; Troncon, C; Turluer, M L; Tyapkin, I A; Tyapkin, P; Tzamarias, S; Uvarov, V; Valenti, G; van Dam, P; Van Eldik, J; Van Lysebetten, A; Van Remortel, N; Van Vulpen, I; Vegni, G; Veloso, F; Venus, W; Verdier, P; Verzi, V; Vilanova, D; Vitale, L; Vrba, V; Wahlen, H; Washbrook, A J; Weiser, C; Wicke, D; Wickens, J; Wilkinson, G; Winter, M; Witek, M; Yushchenko, O P; Zalewska-Bak, A; Zalewski, P; Zavrtanik, D; Zhuravlov, V; Zimin, N I; Zintchenko, A; Zupan, M
2004-01-01
Searches for neutral Higgs bosons produced at LEP in association with Z bosons, in pairs and in the Yukawa process are presented in this paper. Higgs boson decays into b quarks, tau leptons, or other Higgs bosons are considered, giving rise to four-b, four-b+jets, six-b and four-tau final states, as well as mixed modes with b quarks and tau leptons. The whole mass domain kinematically accessible at LEP in these topologies is searched. The analysed data set covers both the LEP1 and LEP2 energy ranges and exploits most of the luminosity recorded by the DELPHI experiment. No convincing evidence for a signal is found, and results are presented in the form of mass-dependent upper bounds on coupling factors (in units of model-independent reference cross-sections) for all processes, allowing interpretation of the data in a large class of models.
Aerodynamic model of transport airplane in extended envelope for simulation of upset recovery
Abramov, Nikolay; Goman, M.; Khrabrov, A. N. (Alexander N.); E. N. Kolesnikov; Sidoryuk, M. E. (Maria E.); Soemarwoto, B.; Smaili, H.
2012-01-01
The paper presents the aerodynamic model in extended flight envelope for a generic airliner with under wing engines and conventional tail developed within the EU Framework Programme (FP7) research project Simulation of Upset Recovery in Aviation (SUPRA) (www.supra.aero). The SUPRA aerodynamic model is covering angles of attack beyond stall and speeds from take-off to cruise flight. The aerodynamic model in extended flight envelope developed for piloted simulation of upset prevention and recov...
Jones, Valerie M.; Rensink, Arend; Brinksma, Hendrik
2005-01-01
Mobile health systems can extend the enterprise computing system of the healthcare provider by bringing services to the patient any time and anywhere. We propose a model-driven design and development methodology for the development of the m-health components in such extended enterprise computing systems. The methodology applies a model-driven design and development approach augmented with formal validation and verification to address quality and correctness and to support model transformation...
Jones, Valerie M.; Rensink, Arend; Brinksma, Hendrik
2005-01-01
Mobile health systems can extend the enterprise computing system of the healthcare provider by bringing services to the patient any time and anywhere. We propose a model-driven design and development methodology for the development of the m-health components in such extended enterprise computing
Extended social force model with a dynamic navigation field for bidirectional pedestrian flow
Jiang, Yan-Qun; Chen, Bo-Kui; Wang, Bing-Hong; Wong, Weng-Fai; Cao, Bing-Yang
2017-10-01
An extended social force model with a dynamic navigation field is proposed to study bidirectional pedestrian movement. The dynamic navigation field is introduced to describe the desired direction of pedestrian motion resulting from the decision-making processes of pedestrians. The macroscopic fundamental diagrams obtained using the extended model are validated against camera-based observations. Numerical results show that this extended model can reproduce collective phenomena in pedestrian traffic, such as dynamic multilane flow and stable separate-lane flow. Pedestrians' path choice behavior significantly affects the probability of congestion and the number of self-organized lanes.
Extended Group Contribution Model for Polyfunctional Phase Equilibria
DEFF Research Database (Denmark)
Abildskov, Jens
Material and energy balances and equilibrium data form the basis of most design calculations. While material and energy balances may be stated without much difficulty, the design engineer is left with a choice between a wide variety of models for describing phase equilibria in the design...... of physical separation processes. In a thermodynamic sense, design requires detailed knowledge of activity coefficients in the phases at equilibrium. The prediction of these quantities from a minimum of experimental data is the broad scope of this thesis. Adequate equations exist for predicting vapor-liquid...
Extended Group Contribution Model for Polyfunctional Phase Equilibria
DEFF Research Database (Denmark)
Abildskov, Jens
Material and energy balances and equilibrium data form the basis of most design calculations. While material and energy balances may be stated without much difficulty, the design engineer is left with a choice between a wide variety of models for describing phase equilibria in the design...... of physical separation processes. In a thermodynamic sense, design requires detailed knowledge of activity coefficients in the phases at equilibrium. The prediction of these quantities from a minimum of experimental data is the broad scope of this thesis. Adequate equations exist for predicting vapor...
Extended Group Contribution Model for Polyfunctional Phase Equilibria
DEFF Research Database (Denmark)
Abildskov, Jens
of physical separation processes. In a thermodynamic sense, design requires detailed knowledge of activity coefficients in the phases at equilibrium. The prediction of these quantities from a minimum of experimental data is the broad scope of this thesis. Adequate equations exist for predicting vapor-liquid......Material and energy balances and equilibrium data form the basis of most design calculations. While material and energy balances may be stated without much difficulty, the design engineer is left with a choice between a wide variety of models for describing phase equilibria in the design...
Floquet topological semimetal phases of an extended kicked Harper model
Bomantara, Raditya Weda; Raghava, Gudapati Naresh; Zhou, Longwen; Gong, Jiangbin
2016-02-01
Recent discoveries on topological characterization of gapless systems have attracted interest in both theoretical studies and experimental realizations. Examples of such gapless topological phases are Weyl semimetals, which exhibit three-dimensional (3D) Dirac cones (Weyl points), and nodal line semimetals, which are characterized by line nodes (two bands touching along a line). Inspired by our previous discoveries that the kicked Harper model exhibits many fascinating features of Floquet topological phases, in this paper we consider a generalization of the model, where two additional periodic system parameters are introduced into the Hamiltonian to serve as artificial dimensions, so as to simulate a 3 D periodically driven system. We observe that by increasing the hopping strength and the kicking strength of the system, many new Floquet band touching points at Floquet quasienergies 0 and π will start to appear. Some of them are Weyl points, while the others form line nodes in the parameter space. By taking open boundary conditions along the physical dimension, edge states analogous to Fermi arcs in static Weyl semimetal systems are observed. Finally, by designing an adiabatic pumping scheme, the chirality of the Floquet-band Weyl points and the π Berry phase around Floquet-band line nodes can be manifested.
EXTENDE MODEL OF COMPETITIVITY THROUG APPLICATION OF NEW APPROACH DIRECTIVES
Directory of Open Access Journals (Sweden)
Slavko Arsovski
2009-03-01
Full Text Available The basic subject of this work is the model of new approach impact on quality and safety products, and competency of our companies. This work represents real hypothesis on the basis of expert's experiences, in regard to that the infrastructure with using new approach directives wasn't examined until now, it isn't known which product or industry of Serbia is related to directives of the new approach and CE mark, and it is not known which are effects of the use of the CE mark. This work should indicate existing quality reserves and product's safety, the level of possible competency improvement and increasing the profit by discharging new approach directive requires.
Extended Mixed-Efects Item Response Models with the MH-RM Algorithm
Chalmers, R. Philip
2015-01-01
A mixed-effects item response theory (IRT) model is presented as a logical extension of the generalized linear mixed-effects modeling approach to formulating explanatory IRT models. Fixed and random coefficients in the extended model are estimated using a Metropolis-Hastings Robbins-Monro (MH-RM) stochastic imputation algorithm to accommodate for…
Bipolarons in one-dimensional extended Peierls-Hubbard models
Sous, John; Chakraborty, Monodeep; Krems, Roman; Berciu, Mona
2017-04-01
We study two particles in an infinite chain and coupled to phonons by interactions that modulate their hopping as described by the Peierls/Su-Schrieffer-Heeger (SSH) model. In the case of hard-core bare particles, we show that exchange of phonons generates effective nearest-neighbor repulsion between particles and also gives rise to interactions that move the pair as a whole. The two-polaron phase diagram exhibits two sharp transitions, leading to light dimers at strong coupling and the flattening of the dimer dispersion at some critical values of the parameters. This dimer (quasi)self-trapping occurs at coupling strengths where single polarons are mobile. On the other hand, in the case of soft-core particles/ spinfull fermions, we show that phonon-mediated interactions are attractive and result in strongly bound and mobile bipolarons in a wide region of parameter space. This illustrates that, depending on the strength of the phonon-mediated interactions and statistics of bare particles, the coupling to phonons may completely suppress or strongly enhance quantum transport of correlated particles. This work was supported by NSERC of Canada and the Stewart Blusson Quantum Matter Institute.
National Aeronautics and Space Administration — Estimation of aerodynamic models for the control of damaged aircraft using an innovative differential vortex lattice method tightly coupled with an extended Kalman...
Kieffer, Michael J.; Petscher, Yaacov; Proctor, C. Patrick; Silverman, Rebecca D.
2016-01-01
Language comprehension is crucial to reading. However, theoretical models and recent research raise questions about what constitutes this multifaceted domain. We present two related studies examining the dimensionality of language comprehension and relations to reading comprehension in the upper elementary grades. Studies 1 (Grade 6; N = 148) and…
The Extended Perturbation Method: New Insights on the New Keynesian Model
DEFF Research Database (Denmark)
Andreasen, Martin Møller; Kronborg, Anders Farver
This paper introduces the extended perturbation method, which improves upon standard perturbation by removing approximation errors under perfect foresight. For the New Keynesian model, we show that standard perturbation generates explosive sample paths because it does not account for the upper...... bound on inflation as implied by Calvo pricing. In contrast, extended perturbation generates stable dynamics as it enforces this bound. Extended perturbation also adds to existing evidence on downward nominal wage rigidities in the New Keynesian model, as we only find support for this friction when...
Extended ARMA models for estimating price developments on day-ahead electricity markets
Energy Technology Data Exchange (ETDEWEB)
Swider, Derk J. [Institute of Energy Economics and the Rational Use of Energy, University of Stuttgart, Hessbruehlstr. 49a, 70565 Stuttgart (Germany); Weber, Christoph [University of Duisburg-Essen, Universitaetsstr. 12, 45117 Essen (Germany)
2007-04-15
In this paper extended models for estimating price developments on electricity markets are presented. The models consider deviations from the normality hypothesis of the prices. Based on an ARMA model combination with GARCH, Gaussian-mixture and switching-regime approaches are comparatively discussed. The comparison is based on historic electricity prices of the spot and two reserve markets in Germany. It is shown that the proposed extended models lead to significantly improved representations of the considered stochastic price processes. It is inferred that these models may be preferred for estimating price developments on electricity markets. (author)
Comprehensive mechanisms for combustion chemistry: Experiment, modeling, and sensitivity analysis
Energy Technology Data Exchange (ETDEWEB)
Dryer, F.L.; Yetter, R.A. [Princeton Univ., NJ (United States)
1993-12-01
This research program is an integrated experimental/numerical effort to study pyrolysis and oxidation reactions and mechanisms for small-molecule hydrocarbon structures under conditions representative of combustion environments. The experimental aspects of the work are conducted in large diameter flow reactors, at pressures from one to twenty atmospheres, temperatures from 550 K to 1200 K, and with observed reaction times from 10{sup {minus}2} to 5 seconds. Gas sampling of stable reactant, intermediate, and product species concentrations provides not only substantial definition of the phenomenology of reaction mechanisms, but a significantly constrained set of kinetic information with negligible diffusive coupling. Analytical techniques used for detecting hydrocarbons and carbon oxides include gas chromatography (GC), and gas infrared (NDIR) and FTIR methods are utilized for continuous on-line sample detection of light absorption measurements of OH have also been performed in an atmospheric pressure flow reactor (APFR), and a variable pressure flow (VPFR) reactor is presently being instrumented to perform optical measurements of radicals and highly reactive molecular intermediates. The numerical aspects of the work utilize zero and one-dimensional pre-mixed, detailed kinetic studies, including path, elemental gradient sensitivity, and feature sensitivity analyses. The program emphasizes the use of hierarchical mechanistic construction to understand and develop detailed kinetic mechanisms. Numerical studies are utilized for guiding experimental parameter selections, for interpreting observations, for extending the predictive range of mechanism constructs, and to study the effects of diffusive transport coupling on reaction behavior in flames. Modeling using well defined and validated mechanisms for the CO/H{sub 2}/oxidant systems.
Model-based safety analysis of a control system using Simulink and Simscape extended models
Directory of Open Access Journals (Sweden)
Shao Nian
2017-01-01
Full Text Available The aircraft or system safety assessment process is an integral part of the overall aircraft development cycle. It is usually characterized by a very high timely and financial effort and can become a critical design driver in certain cases. Therefore, an increasing demand of effective methods to assist the safety assessment process arises within the aerospace community. One approach is the utilization of model-based technology, which is already well-established in the system development, for safety assessment purposes. This paper mainly describes a new tool for Model-Based Safety Analysis. A formal model for an example system is generated and enriched with extended models. Then, system safety analyses are performed on the model with the assistance of automation tools and compared to the results of a manual analysis. The objective of this paper is to improve the increasingly complex aircraft systems development process. This paper develops a new model-based analysis tool in Simulink/Simscape environment.
Component Model of Reading Comprehension for Adult Education Participants
Mellard, Daryl F.; Fall, Emily
2012-01-01
The following insights into the reading skills of 312 participants in adult basic and secondary education programs are based on a principal components analysis of reading components' contributions to variance in reading comprehension. Overall, 75% of variance was explained by four composite variables representing word skills, language…
A Model of Reading Comprehension in Chinese Elementary School Children
Yeung, Pui-sze; Ho, Connie Suk-han; Chan, David Wai-ock; Chung, Kevin Kien-hoa; Wong, Yau-kai
2013-01-01
The relationships of reading-related skills (rapid naming, morphological awareness, syntactic skills, discourse skills, and verbal working memory) and word reading to reading comprehension were examined among 248 Chinese fourth graders in Hong Kong. Multiple regression analysis results showed that syntactic skills (word order knowledge,…
A Conceptual Process Model for Improving Youth Science Comprehension
Skelton, Peter; Seevers, Brenda; Dormody, Tom; Hodnett, Frank
2012-01-01
Improving youth science comprehension in the United States is imperative to reverse current trends in student achievement and to meet an expected shortage of scientists in the future. This lag in achievement scores and need for future scientists is a problem. One challenge is to link inquiry-based learning and experiential education with…
A comprehensive experimental and modeling study of isobutene oxidation
Zhou, Chong-Wen
2016-03-17
Isobutene is an important intermediate in the pyrolysis and oxidation of higher-order branched alkanes, and it is also a component of commercial gasolines. To better understand its combustion characteristics, a series of ignition delay time (IDT) and laminar flame speed (LFS) measurements have been performed. In addition, flow reactor speciation data recorded for the pyrolysis and oxidation of isobutene is also reported. Predictions of an updated kinetic model described herein are compared with each of these data sets, as well as with existing jet-stirred reactor (JSR) species measurements. IDTs of isobutene oxidation were measured in four different shock tubes and in two rapid compression machines (RCMs) under conditions of relevance to practical combustors. The combination of shock tube and RCM data greatly expands the range of available validation data for isobutene oxidation models to pressures of 50 atm and temperatures in the range 666–1715 K. Isobutene flame speeds were measured experimentally at 1 atm and at unburned gas temperatures of 298–398 K over a wide range of equivalence ratios. For the flame speed results, there was good agreement between different facilities and the current model in the fuel-rich region. Ab initio chemical kinetics calculations were carried out to calculate rate constants for important reactions such as H-atom abstraction by hydroxyl and hydroperoxyl radicals and the decomposition of 2-methylallyl radicals. A comprehensive chemical kinetic mechanism has been developed to describe the combustion of isobutene and is validated by comparison to the presently considered experimental measurements. Important reactions, highlighted via flux and sensitivity analyses, include: (a) hydrogen atom abstraction from isobutene by hydroxyl and hydroperoxyl radicals, and molecular oxygen; (b) radical–radical recombination reactions, including 2-methylallyl radical self-recombination, the recombination of 2-methylallyl radicals with
[A new model of comprehensive data linkage--evaluation of its application in femoral neck fracture].
Ohmann, Christian; Smektala, Rüdiger; Pientka, Ludger; Paech, Stefan; Neuhaus, Elke; Rieger, Martin; Schwabe, Wolfgang; Debold, Peter; Jonas, Michael; Hupe, Klaus; Bücker-Nott, Hans-Joachim; Guido, Giani; Szucs, Thomas D
2005-01-01
Aim of the project was a comprehensive assessment of short- and middle-term outcome of femoral neck fracture by linkage and analysis of available data from routine care. For this purpose, a generic model of data linkage was developed, agreed with the data security officer, and practically applied. Included were all patients of the AOK Westphalia-Lippe, who were treated in a general or trauma surgery hospital in 1995/1999 for a femoral neck fracture (ICD-9: 820). For these patients, the linkage was based on the following sources: the data regarding the initial hospital stay were provided by the office of quality assurance of the chamber of physicians of Westphalia-Lippe; the administrative data were provided by the AOKWestphalia-Lippe; and the data evaluating the nursing needs were obtained from the Medical Services of the Health Insurance of Westphalia-Lippe (MDK). This paper presents the model of data linkage and describes its practical implementation; it also presents medical data demonstrating that femoral neck fractures are associated with high mortality and increase of nursing needs in the course of disease. The benefit of the new model is manifold and can be easily extended to other clinical questions.
The Community Multiscale Air Quality (CMAQ) modeling system is extended to simulate ozone, particulate matter, and related precursor distributions throughout the Northern Hemisphere. Modeled processes were examined and enhanced to suitably represent the extended space and timesca...
A Bayesian Reformulation of the Extended Drift-Diffusion Model in Perceptual Decision Making.
Fard, Pouyan R; Park, Hame; Warkentin, Andrej; Kiebel, Stefan J; Bitzer, Sebastian
2017-01-01
Perceptual decision making can be described as a process of accumulating evidence to a bound which has been formalized within drift-diffusion models (DDMs). Recently, an equivalent Bayesian model has been proposed. In contrast to standard DDMs, this Bayesian model directly links information in the stimulus to the decision process. Here, we extend this Bayesian model further and allow inter-trial variability of two parameters following the extended version of the DDM. We derive parameter distributions for the Bayesian model and show that they lead to predictions that are qualitatively equivalent to those made by the extended drift-diffusion model (eDDM). Further, we demonstrate the usefulness of the extended Bayesian model (eBM) for the analysis of concrete behavioral data. Specifically, using Bayesian model selection, we find evidence that including additional inter-trial parameter variability provides for a better model, when the model is constrained by trial-wise stimulus features. This result is remarkable because it was derived using just 200 trials per condition, which is typically thought to be insufficient for identifying variability parameters in DDMs. In sum, we present a Bayesian analysis, which provides for a novel and promising analysis of perceptual decision making experiments.
A Bayesian Reformulation of the Extended Drift-Diffusion Model in Perceptual Decision Making
Fard, Pouyan R.; Park, Hame; Warkentin, Andrej; Kiebel, Stefan J.; Bitzer, Sebastian
2017-01-01
Perceptual decision making can be described as a process of accumulating evidence to a bound which has been formalized within drift-diffusion models (DDMs). Recently, an equivalent Bayesian model has been proposed. In contrast to standard DDMs, this Bayesian model directly links information in the stimulus to the decision process. Here, we extend this Bayesian model further and allow inter-trial variability of two parameters following the extended version of the DDM. We derive parameter distributions for the Bayesian model and show that they lead to predictions that are qualitatively equivalent to those made by the extended drift-diffusion model (eDDM). Further, we demonstrate the usefulness of the extended Bayesian model (eBM) for the analysis of concrete behavioral data. Specifically, using Bayesian model selection, we find evidence that including additional inter-trial parameter variability provides for a better model, when the model is constrained by trial-wise stimulus features. This result is remarkable because it was derived using just 200 trials per condition, which is typically thought to be insufficient for identifying variability parameters in DDMs. In sum, we present a Bayesian analysis, which provides for a novel and promising analysis of perceptual decision making experiments. PMID:28553219
A Bayesian Reformulation of the Extended Drift-Diffusion Model in Perceptual Decision Making
Directory of Open Access Journals (Sweden)
Pouyan R. Fard
2017-05-01
Full Text Available Perceptual decision making can be described as a process of accumulating evidence to a bound which has been formalized within drift-diffusion models (DDMs. Recently, an equivalent Bayesian model has been proposed. In contrast to standard DDMs, this Bayesian model directly links information in the stimulus to the decision process. Here, we extend this Bayesian model further and allow inter-trial variability of two parameters following the extended version of the DDM. We derive parameter distributions for the Bayesian model and show that they lead to predictions that are qualitatively equivalent to those made by the extended drift-diffusion model (eDDM. Further, we demonstrate the usefulness of the extended Bayesian model (eBM for the analysis of concrete behavioral data. Specifically, using Bayesian model selection, we find evidence that including additional inter-trial parameter variability provides for a better model, when the model is constrained by trial-wise stimulus features. This result is remarkable because it was derived using just 200 trials per condition, which is typically thought to be insufficient for identifying variability parameters in DDMs. In sum, we present a Bayesian analysis, which provides for a novel and promising analysis of perceptual decision making experiments.
Quinn, Jamie M; Wagner, Richard K; Petscher, Yaacov; Lopez, Danielle
2015-01-01
The present study followed a sample of first-grade (N = 316, Mage = 7.05 at first test) through fourth-grade students to evaluate dynamic developmental relations between vocabulary knowledge and reading comprehension. Using latent change score modeling, competing models were fit to the repeated measurements of vocabulary knowledge and reading comprehension to test for the presence of leading and lagging influences. Univariate models indicated growth in vocabulary knowledge, and reading comprehension was determined by two parts: constant yearly change and change proportional to the previous level of the variable. Bivariate models indicated previous levels of vocabulary knowledge acted as leading indicators of reading comprehension growth, but the reverse relation was not found. Implications for theories of developmental relations between vocabulary and reading comprehension are discussed. © 2014 The Authors. Child Development © 2014 Society for Research in Child Development, Inc.
Directory of Open Access Journals (Sweden)
Yi Tang
2017-11-01
Full Text Available With increasing penetration of wind power into the power system, wind power participation in frequency regulation is regarded as a beneficial strategy to improve the dynamic frequency response characteristics of power systems. The traditional power system frequency response (SFR model, which only includes synchronous generators, is no longer suitable for power systems with high penetrated wind power. An extended SFR model, based on the reduced-order model of wind turbine generator (WTG and the traditional SFR model, is presented in this paper. In the extended SFR model, the reduced-order model of WTG with combined frequency control is deduced by employing small signal analysis theory. Afterwards, the stability analysis of a closed-loop control system for the extended SFR model is carried out. Time-domain simulations using a test system are performed to validate the effectiveness of the extended SFR model; this model can provide a simpler, clearer and faster way to analyze the dynamic frequency response characteristic for a high-wind integrated power systems. The impact of additional frequency control parameters and wind speed disturbances on the system dynamic frequency response characteristics are investigated.
Dems, Maciej; Beling, Piotr; Gebski, Marcin; Piskorski, Łukasz; Walczak, Jarosław; Kuc, Maciej; Frasunkiewicz, Leszek; Wasiak, Michał; Sarzała, Robert; Czyszanowski, Tomasz
2015-03-01
In the talk we show the process of modeling complete physical properties of VCSELs and we present a step-by-step development of its complete multi-physics model, gradually improving its accuracy. Then we introduce high contrast gratings to the VCSEL design, which strongly complicates its optical modeling, making the comprehensive multi-physics VCSEL simulation a challenging task. We show, however, that a proper choice of a self-consistent simulation algorithm can still make such a simulation a feasible one, which is necessary for an efficient optimization of the laser prior to its costly manufacturing.
Extending the Langevin model to variable-density pressure-gradient-driven turbulence
Bakosi, J
2011-01-01
We extend the generalized Langevin model, originally developed for the Lagrangian fluid particle velocity in constant-density shear-driven turbulence, to variable-density (VD) pressure-gradient-driven flows. VD effects due to non-uniform mass concentrations (e.g. mixing of different species) are considered. In the extended model large density fluctuations leading to large differential fluid accelerations are accounted for. This is an essential ingredient to represent the strong coupling between the density and velocity fields in VD hydrodynamics driven by active scalar mixing. The small scale anisotropy, a fundamentally "non-Kolmogorovian" feature of pressure-gradient-driven flows, is captured by a tensorial stochastic diffusion term. The extension is so constructed that it reduces to the original Langevin model in the limit of constant density. We show that coupling a Lagrangian mass-density particle model to the proposed extended velocity equation results in a statistical representation of VD turbulence tha...
Extending the Real-Time Maude Semantics of Ptolemy to Hierarchical DE Models
Directory of Open Access Journals (Sweden)
Peter Csaba Ölveczky
2010-09-01
Full Text Available This paper extends our Real-Time Maude formalization of the semantics of flat Ptolemy II discrete-event (DE models to hierarchical models, including modal models. This is a challenging task that requires combining synchronous fixed-point computations with hierarchical structure. The synthesis of a Real-Time Maude verification model from a Ptolemy II DE model, and the formal verification of the synthesized model in Real-Time Maude, have been integrated into Ptolemy II, enabling a model-engineering process that combines the convenience of Ptolemy II DE modeling and simulation with formal verification in Real-Time Maude.
Klein, Daniel; Zezula, Ivan
The extended growth curve model is discussed in this paper. There are two versions of the model studied in the literature, which differ in the way how the column spaces of the design matrices are nested. The nesting is applied either to the between-individual or to the within-individual design
3D Printed Molecules and Extended Solid Models for Teaching Symmetry and Point Groups
Scalfani, Vincent F.; Vaid, Thomas P.
2014-01-01
Tangible models help students and researchers visualize chemical structures in three dimensions (3D). 3D printing offers a unique and straightforward approach to fabricate plastic 3D models of molecules and extended solids. In this article, we prepared a series of digital 3D design files of molecular structures that will be useful for teaching…
2D Modeling and Classification of Extended Objects in a Network of HRR Radars
Fasoula, A.
2011-01-01
In this thesis, the modeling of extended objects with low-dimensional representations of their 2D geometry is addressed. The ultimate objective is the classification of the objects using libraries of such compact 2D object models that are much smaller than in the state-of-the-art classification
Characteristics of the Frontier Extended Stay Clinic: a new facility model
Directory of Open Access Journals (Sweden)
Rosyland Frazier
2013-08-01
Full Text Available Purpose. In 2004, 5 remote clinics – 4 in rural frontier communities in Alaska and 1 in Washington – were funded to pilot and examine the effectiveness and appropriateness of a new facility model. Transporting patients from these locations to higher levels of care is not always possible requiring these facilities to expand their scope of services and provide care for extended periods. The Frontier Extended Stay Clinic (FESC model is staffed and equipped to provide the combined services usually found in the separate settings of an outpatient primary-care clinic, inpatient acute care hospital and emergency room. This is a descriptive study of the characteristics of these pilot facilities and an analysis of patient utilization and outcomes. Methods . The 5 clinics collected outcome data for 2,226 extended-stay encounters of 4 hours or longer from 15 September 2005 to 14 September 2010. Data from these extended-stay encounters were summarized, and descriptive statistics were used to describe: number and duration of encounters, when the encounters started, chief compliant, discharge diagnoses, transfer destination, Medicare and Medicaid eligibility, and type of encounter. Findings . From 2005 to 2010, the mean duration of an extended-stay encounter was 9.1 hours. All of the clinics experienced many extended-stay encounters that were initiated or continued after normal business hours. The 5 most frequent diagnoses at discharge for extended encounters were cardiovascular, gastrointestinal, injury, substance abuse and pneumonia/bronchitis. Almost half, 47.6%, of extended-stay encounters resulted in discharge of the patient without a need for either non-urgent follow-up referral or transport. Extended-stay encounters that ended in a patient being transported to another medical facility were 43.7% of the total. More than a quarter (26.9% of extended-stay encounters were eligible for Medicare payment. Conclusion . While many of communities can support
The Flipped Classroom Model to Develop Egyptian EFL Students' Listening Comprehension
Ahmad, Samah Zakareya
2016-01-01
The present study aimed at investigating the effect of the flipped classroom model on Egyptian EFL students' listening comprehension. A one-group pre-posttest design was adopted. Thirty-four 3rd-year EFL students at the Faculty of Education, Suez University, were pretested on listening comprehension before the experiment and then posttested after…
Research on a Frame-Based Model of Reading Comprehension. Final Report.
Goldstein, Ira
This report summarizes computational investigations of language comprehension based on Marvin Minsky's theory of frames, a recent advance in artifical intelligence theories about the representation of knowledge. The investigations discussed explored frame theory as a basis for text comprehension by implementing models of the theory and developing…
Reconciling Time, Space and Function: A New Dorsal-Ventral Stream Model of Sentence Comprehension
Bornkessel-Schlesewsky, Ina; Schlesewsky, Matthias
2013-01-01
We present a new dorsal-ventral stream framework for language comprehension which unifies basic neurobiological assumptions (Rauschecker & Scott, 2009) with a cross-linguistic neurocognitive sentence comprehension model (eADM; Bornkessel & Schlesewsky, 2006). The dissociation between (time-dependent) syntactic structure-building and…
Fermion Masses and Mixing in SUSY Grand Unified Gauge Models with Extended Gut Gauge Groups
Energy Technology Data Exchange (ETDEWEB)
Chou, Chih-Lung
2005-04-05
The authors discuss a class of supersymmetric (SUSY) grand unified gauge (GUT) models based on the GUT symmetry G x G or G x G x G, where G denotes the GUT group that has the Standard Model symmetry (SU(3){sub c} x SU(2){sub L} x U(1){sub Y}) embedded as a subgroup. As motivated from string theory, these models are constructed without introducing any Higgs field of rani two or higher. Thus all the Higgs fields are in the fundamental representations of the extended GUT symmetry or, when G = SO(10), in the spinorial representation. These Higgs fields, when acquiring their vacuum expectation values, would break the extended GUT symmetry down to the Standard Model symmetry. In this dissertation, they argue that the features required of unified models, such as the Higgs doublet-triplet splitting, proton stability, and the hierarchy of fermion masses and mixing angles, could have natural explanations in the framework of the extended SUSY GUTs. Furthermore, they argue that the frameworks used previously to construct SO(10) GUT models using adjoint Higgs fields can naturally arise from the SO(10) x SO(10) and SO(10) x SO(10) x SO(10) models by integrating out heavy fermions. This observation thus suggests that the traditional SUSY GUT SO(10) theories can be viewed as the low energy effective theories generated by breaking the extended GUT symmetry down to the SO(10) symmetry.
The Implementation of C-ID, R2D2 Model on Learning Reading Comprehension
Rayanto, Yudi Hari; Rusmawan, Putu Ngurah
2016-01-01
The purposes of this research are to find out, (1) whether C-ID, R2D2 model is effective to be implemented on learning Reading comprehension, (2) college students' activity during the implementation of C-ID, R2D2 model on learning Reading comprehension, and 3) college students' learning achievement during the implementation of C-ID, R2D2 model on…
Fahimi, Farzad; Yaseen, Zaher Mundher; El-shafie, Ahmed
2017-05-01
Since the middle of the twentieth century, artificial intelligence (AI) models have been used widely in engineering and science problems. Water resource variable modeling and prediction are the most challenging issues in water engineering. Artificial neural network (ANN) is a common approach used to tackle this problem by using viable and efficient models. Numerous ANN models have been successfully developed to achieve more accurate results. In the current review, different ANN models in water resource applications and hydrological variable predictions are reviewed and outlined. In addition, recent hybrid models and their structures, input preprocessing, and optimization techniques are discussed and the results are compared with similar previous studies. Moreover, to achieve a comprehensive view of the literature, many articles that applied ANN models together with other techniques are included. Consequently, coupling procedure, model evaluation, and performance comparison of hybrid models with conventional ANN models are assessed, as well as, taxonomy and hybrid ANN models structures. Finally, current challenges and recommendations for future researches are indicated and new hybrid approaches are proposed.
Yeari, Menahem; van den Broek, Paul
2016-09-01
It is a well-accepted view that the prior semantic (general) knowledge that readers possess plays a central role in reading comprehension. Nevertheless, computational models of reading comprehension have not integrated the simulation of semantic knowledge and online comprehension processes under a unified mathematical algorithm. The present article introduces a computational model that integrates the landscape model of comprehension processes with latent semantic analysis representation of semantic knowledge. In three sets of simulations of previous behavioral findings, the integrated model successfully simulated the activation and attenuation of predictive and bridging inferences during reading, as well as centrality estimations and recall of textual information after reading. Analyses of the computational results revealed new theoretical insights regarding the underlying mechanisms of the various comprehension phenomena.
Extended charge banking model of dual path shocks for implantable cardioverter defibrillators.
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.
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,
Testing Different Types of Genotype-Environment Correlation: An Extended Children-of Twins Model
Narusyte, Jurgita; Neiderhiser, Jenae M.; D'Onofrio, Brian M.; Reiss, David; Spotts, Erica L.; Ganiban, Jody; Lichtenstein, Paul
2008-01-01
This study presents an extended children-of-twins model, which allowed the authors to test the direction of the association between parenting and child adjustment. Three mechanisms were examined: direct phenotypic influence of parenting on child behavior (controlling for both parental and child genotype), passive genotype-environment correlation,…
A novel model for extending international co-operation in science and education
de Boer, S.J.; Ji-zehn, Q.
2004-01-01
Journal of Zhejiang University SCIENCE (ISSN 1009-3095, Monthly) 2004 Vol. 5 No. 3 p.358-364 --------------------------------------------------------------------------------A novel model for extending international co-operation in science and educationDE BOER Sirp J.1, QIU Ji-zhen 2(1International
Tribimaximal mixing in a viable family symmetry unified model with an extended seesaw mechanism
Bazzocchi, F.; Varzielas, I.D.
2009-01-01
We present a grand unified model based on SO(10) with a Δ(27) family symmetry. Fermion masses and mixings are fitted and agree well with experimental values. An extended seesaw mechanism plays a key role in the generation of the leptonic mixing, which is approximately tribimaximal. © 2009 The
Invariance of an Extended Technology Acceptance Model Across Gender and Age Group
Ahmad, Tunku Badariah Tunku; Madarsha, Kamal Basha; Zainuddin, Ahmad Marzuki; Ismail, Nik Ahmad Hisham; Khairani, Ahmad Zamri; Nordin, Mohamad Sahari
2011-01-01
In this study, we examined the likelihood of a TAME (extended technology acceptance model), in which the interrelationships among computer self-efficacy, perceived usefulness, intention to use and self-reported use of computer-mediated technology were tested. In addition, the gender- and age-invariant of its causal structure were evaluated. The…
Directory of Open Access Journals (Sweden)
Ahmad Neirameh
2018-07-01
Full Text Available In this study, we propose a new algorithm to find exact solitary wave solutions of nonlinear time- fractional order of extended biological population model. The new algorithm basically illustrates how two powerful algorithms, conformable fractional derivative and the homogeneous balance method can be combined and used to get exact solutions of fractional partial differential equations.
Stall Recovery in a Centrifuge-Based Flight Simulator With an Extended Aerodynamic Model
Ledegang, W.D.; Groen, E.L.
2015-01-01
We investigated the performance of 12 airline pilots in recovering from an asymmetrical stall in a flight simulator featuring an extended aerodynamic model of a transport-category aircraft, and a centrifuge-based motion platform capable of generating enhanced buffet motion and g-cueing. All pilots
Perrault, Evan K.; Clark, Scott K.
2018-01-01
Purpose: A planet that can no longer sustain life is a frightening thought--and one that is often present in mass media messages. Therefore, this study aims to test the components of a classic fear appeal theory, the extended parallel process model (EPPM) and to determine how well its constructs predict sustainability behavioral intentions. This…
Modeling of VSC-Based Power Systems in The Extended Harmonic Domain
DEFF Research Database (Denmark)
Esparza, Miguel; Segundo-Ramirez, Juan; Kwon, Jun Bum
2017-01-01
Averaged modeling is a commonly used approach used to obtain mathematical representations of VSC-based systems. However, essential characteristics mainly related to the modulation process and the harmonic distortion of the signals are not able to be accurately captured and analyzed. The extended ...
Predicting the sky from 30 MHz to 800 GHz: the extended Global Sky Model
Liu, Adrian
We propose to construct the extended Global Sky Model (eGSM), a software package and associated data products that are capable of generating maps of the sky at any frequency within a broad range (30 MHz to 800 GHz). The eGSM is constructed from archival data, and its outputs will include not only "best estimate" sky maps, but also accurate error bars and the ability to generate random realizations of missing modes in the input data. Such views of the sky are crucial in the practice of precision cosmology, where our ability to constrain cosmological parameters and detect new phenomena (such as B-mode signatures from primordial gravitational waves, or spectral distortions of the Cosmic Microwave Background; CMB) rests crucially on our ability to remove systematic foreground contamination. Doing so requires empirical measurements of the foreground sky brightness (such as that arising from Galactic synchrotron radiation, among other sources), which are typically performed only at select narrow wavelength ranges. We aim to transcend traditional wavelength limits by optimally combining existing data to provide a comprehensive view of the foreground sky at any frequency within the broad range of 30 MHz to 800 GHz. Previous efforts to interpolate between multi-frequency maps resulted in the Global Sky Model (GSM) of de Oliveira-Costa et al. (2008), a software package that outputs foreground maps at any frequency of the user's choosing between 10 MHz and 100 GHz. However, the GSM has a number of shortcomings. First and foremost, the GSM does not include the latest archival data from the Planck satellite. Multi-frequency models depend crucially on data from Planck, WMAP, and COBE to provide high-frequency "anchor" maps. Another crucial shortcoming is the lack of error bars in the output maps. Finally, the GSM is only able to predict temperature (i.e., total intensity) maps, and not polarization information. With the recent release of Planck's polarized data products, the
Extended Holography: Double-Trace Deformation and Brane-Induced Gravity Models
Barvinsky, A. O.
2017-03-01
We put forward a conjecture that for a special class of models - models of the double-trace deformation and brane-induced gravity types - the principle of holographic dualitiy can be extended beyond conformal invariance and anti-de Sitter (AdS) isometry. Such an extension is based on a special relation between functional determinants of the operators acting in the bulk and on the boundary.
Long-Range Charge Order in the Extended Holstein-Hubbard Model
Miyao, Tadahiro
2016-10-01
This study investigated the extended Holstein-Hubbard model at half-filling as a model for describing the interplay of electron-electron and electron-phonon couplings. When the electron-phonon and nearest-neighbor electron-electron interactions are strong, we prove the existence of long-range charge order in three or more dimensions at a sufficiently low temperature. As a result, we rigorously justify the phase competition between the antiferromagnetism and charge orders.
Ferrari, G.; Kozarski, M.; Gu, Y. J.; De Lazzari, C.; Di Molfetta, A.; Palko, K. J.; Zielinski, K.; Gorczynska, K.; Darowski, M.; Rakhorst, G.
2008-01-01
Purpose: Application of a comprehensive, user-friendly, digital computer circulatory model to estimate hemodynamic and ventricular variables. Methods: The closed-loop lumped parameter circulatory model represents the circulation at the level of large vessels. A variable elastance model reproduces
A Local Search Modeling for Constrained Optimum Paths Problems (Extended Abstract
Directory of Open Access Journals (Sweden)
Quang Dung Pham
2009-10-01
Full Text Available Constrained Optimum Path (COP problems appear in many real-life applications, especially on communication networks. Some of these problems have been considered and solved by specific techniques which are usually difficult to extend. In this paper, we introduce a novel local search modeling for solving some COPs by local search. The modeling features the compositionality, modularity, reuse and strengthens the benefits of Constrained-Based Local Search. We also apply the modeling to the edge-disjoint paths problem (EDP. We show that side constraints can easily be added in the model. Computational results show the significance of the approach.
Energy parameters and novel algorithms for an extended nearest neighbor energy model of RNA.
Dotu, Ivan; Mechery, Vinodh; Clote, Peter
2014-01-01
We describe the first algorithm and software, RNAenn, to compute the partition function and minimum free energy secondary structure for RNA with respect to an extended nearest neighbor energy model. Our next-nearest-neighbor triplet energy model appears to lead to somewhat more cooperative folding than does the nearest neighbor energy model, as judged by melting curves computed with RNAenn and with two popular software implementations for the nearest-neighbor energy model. A web server is available at http://bioinformatics.bc.edu/clotelab/RNAenn/.
A comprehensive Network Security Risk Model for process control networks.
Henry, Matthew H; Haimes, Yacov Y
2009-02-01
The risk of cyber attacks on process control networks (PCN) is receiving significant attention due to the potentially catastrophic extent to which PCN failures can damage the infrastructures and commodity flows that they support. Risk management addresses the coupled problems of (1) reducing the likelihood that cyber attacks would succeed in disrupting PCN operation and (2) reducing the severity of consequences in the event of PCN failure or manipulation. The Network Security Risk Model (NSRM) developed in this article provides a means of evaluating the efficacy of candidate risk management policies by modeling the baseline risk and assessing expectations of risk after the implementation of candidate measures. Where existing risk models fall short of providing adequate insight into the efficacy of candidate risk management policies due to shortcomings in their structure or formulation, the NSRM provides model structure and an associated modeling methodology that captures the relevant dynamics of cyber attacks on PCN for risk analysis. This article develops the NSRM in detail in the context of an illustrative example.
STAC: a comprehensive sensor fusion model for scene characterization
Kira, Zsolt; Wagner, Alan R.; Kennedy, Chris; Zutty, Jason; Tuell, Grady
2015-05-01
We are interested in data fusion strategies for Intelligence, Surveillance, and Reconnaissance (ISR) missions. Advances in theory, algorithms, and computational power have made it possible to extract rich semantic information from a wide variety of sensors, but these advances have raised new challenges in fusing the data. For example, in developing fusion algorithms for moving target identification (MTI) applications, what is the best way to combine image data having different temporal frequencies, and how should we introduce contextual information acquired from monitoring cell phones or from human intelligence? In addressing these questions we have found that existing data fusion models do not readily facilitate comparison of fusion algorithms performing such complex information extraction, so we developed a new model that does. Here, we present the Spatial, Temporal, Algorithm, and Cognition (STAC) model. STAC allows for describing the progression of multi-sensor raw data through increasing levels of abstraction, and provides a way to easily compare fusion strategies. It provides for unambiguous description of how multi-sensor data are combined, the computational algorithms being used, and how scene understanding is ultimately achieved. In this paper, we describe and illustrate the STAC model, and compare it to other existing models.
A comprehensive model to predict mitotic division in budding yeasts.
Sutradhar, Sabyasachi; Yadav, Vikas; Sridhar, Shreyas; Sreekumar, Lakshmi; Bhattacharyya, Dibyendu; Ghosh, Santanu Kumar; Paul, Raja; Sanyal, Kaustuv
2015-11-05
High-fidelity chromosome segregation during cell division depends on a series of concerted interdependent interactions. Using a systems biology approach, we built a robust minimal computational model to comprehend mitotic events in dividing budding yeasts of two major phyla: Ascomycota and Basidiomycota. This model accurately reproduces experimental observations related to spindle alignment, nuclear migration, and microtubule (MT) dynamics during cell division in these yeasts. The model converges to the conclusion that biased nucleation of cytoplasmic microtubules (cMTs) is essential for directional nuclear migration. Two distinct pathways, based on the population of cMTs and cortical dyneins, differentiate nuclear migration and spindle orientation in these two phyla. In addition, the model accurately predicts the contribution of specific classes of MTs in chromosome segregation. Thus we present a model that offers a wider applicability to simulate the effects of perturbation of an event on the concerted process of the mitotic cell division. © 2015 Sutradhar, Yadav, Sridhar, et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).
Towards a comprehensive model for a resonant nanoelectromechanical system
Calvert, S. L.; Shen, Y.; Sabater, A. B.; Mohammadi, S.; Rhoads, J. F.
2015-09-01
The mass production and very large scale integration (VLSI) of micro/nanoelectromechanical systems (M/NEMS) requires the development and use of accurate models and simulations, which are capable of rapidly evaluating potential designs. Because of the large range of applications that have been proposed for M/NEMS, the most useful models are those that can accurately capture a system’s response under widely varying input and operating conditions. This allows the M/NEMS devices to be treated as well understood circuit components in simulation contexts. It is towards this end that a first-principles based model is proposed for a resonant nanosystem inclusive of an electrostatically-actuated fixed-fixed beam resonator, test equipment and system parasitics. By encoding the algebraic and differential equations which describe the system into circuit components using Verilog-A, an experimental test setup was simulated using Spectre and subsequently compared to experimental results for qualitative validation of the model. The simulation was then used to investigate the behavior of a representative device for a basic input configuration that more closely represents a final-use scenario for the nanoresonator. Discrepancies between the commonly-employed experimental methodology and the practical final-use scenario are discussed and used as a platform to encourage the development of improved experimental methodologies, while also emphasizing the need for robust and accurate system-level models.
An extended continuum model considering optimal velocity change with memory and numerical tests
Qingtao, Zhai; Hongxia, Ge; Rongjun, Cheng
2018-01-01
In this paper, an extended continuum model of traffic flow is proposed with the consideration of optimal velocity changes with memory. The new model's stability condition and KdV-Burgers equation considering the optimal velocities change with memory are deduced through linear stability theory and nonlinear analysis, respectively. Numerical simulation is carried out to study the extended continuum model, which explores how optimal velocity changes with memory affected velocity, density and energy consumption. Numerical results show that when considering the effects of optimal velocity changes with memory, the traffic jams can be suppressed efficiently. Both the memory step and sensitivity parameters of optimal velocity changes with memory will enhance the stability of traffic flow efficiently. Furthermore, numerical results demonstrates that the effect of optimal velocity changes with memory can avoid the disadvantage of historical information, which increases the stability of traffic flow on road, and so it improve the traffic flow stability and minimize cars' energy consumptions.
Modeling and Extended State Observer Based Dynamic Surface Control for Cold Rolling Mill System
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Xu Li
2016-01-01
Full Text Available The modeling and control problems are investigated for cold rolling mill system. Firstly, we establish a monitor automatic gauge control (MAGC model for a practical cold rolling mill system. The new model is with mismatched uncertainties. Then, an extended state observer (ESO is developed to estimate uncertainties. In the general high-order systems, the ESO is also used to estimate states. By dynamic surface control method, we design the controller to guarantee stabilization of the cold rolling mill system. Furthermore, we extend proposed method to general high-order systems, in which we analyze the difference from cold rolling mill system. Finally, simulation results for MAGC system are presented to demonstrate the effectiveness of the proposed control strategy.
A comprehensive gaze stabilization controller based on cerebellar internal models
DEFF Research Database (Denmark)
Vannucci, Lorenzo; Falotico, Egidio; Tolu, Silvia
2017-01-01
based on the coordination of VCR and VOR and OKR. The model, inspired by neuroscientific cerebellar theories, is provided with learning and adaptation capabilities based on internal models. We present the results for the gaze stabilization model on three sets of experiments conducted on the SABIAN robot......Gaze stabilization is essential for clear vision; it is the combined effect of two reflexes relying on vestibular inputs: the vestibulocollic reflex (VCR), which stabilizes the head in space and the vestibulo-ocular reflex (VOR), which stabilizes the visual axis to minimize retinal image motion...... and on the iCub simulator, validating the robustness of the proposed control method. The first set of experiments focused on the controller response to a set of disturbance frequencies along the vertical plane. The second shows the performances of the system under three-dimensional disturbances. The last set...
Conflict Detection for Edits on Extended Feature Models using Symbolic Graph Transformation
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Frederik Deckwerth
2016-03-01
Full Text Available Feature models are used to specify variability of user-configurable systems as appearing, e.g., in software product lines. Software product lines are supposed to be long-living and, therefore, have to continuously evolve over time to meet ever-changing requirements. Evolution imposes changes to feature models in terms of edit operations. Ensuring consistency of concurrent edits requires appropriate conflict detection techniques. However, recent approaches fail to handle crucial subtleties of extended feature models, namely constraints mixing feature-tree patterns with first-order logic formulas over non-Boolean feature attributes with potentially infinite value domains. In this paper, we propose a novel conflict detection approach based on symbolic graph transformation to facilitate concurrent edits on extended feature models. We describe extended feature models formally with symbolic graphs and edit operations with symbolic graph transformation rules combining graph patterns with first-order logic formulas. The approach is implemented by combining eMoflon with an SMT solver, and evaluated with respect to applicability.
Practical Modeling and Comprehensive System Identification of a BLDC Motor
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Changle Xiang
2015-01-01
Full Text Available The aim of this paper is to outline all the steps in a rigorous and simple procedure for system identification of BLDC motor. A practical mathematical model for identification is derived. Frequency domain identification techniques and time domain estimation method are combined to obtain the unknown parameters. The methods in time domain are founded on the least squares approximation method and a disturbance observer. Only the availability of experimental data for rotor speed and armature current are required for identification. The proposed identification method is systematically investigated, and the final identified model is validated by experimental results performed on a typical BLDC motor in UAV.
Marriage of Electromagnetism and Gravity in an Extended Space Model and Astrophysical Phenomena
Andreev, V. A.; Tsipenyuk, D. Yu.
2013-09-01
The generalization of Einstein's special theory of relativity (SRT) is proposed. In this model the possibility of unification of scalar gravity and electromagnetism into a single unified field is considered. Formally, the generalization of the SRT is that instead of (1+3)-dimensional Minkowski space the (1+4)-dimensional extension G is considered. As a fifth additional coordinate the interval S is used. This value is saved under the usual Lorentz transformations in Minkowski space M, but it changes when the transformations in the extended space G are used. We call this model the extended space model (ESM). From a physical point of view our expansion means that processes in which the rest mass of the particles changes are acceptable now. If the rest mass of a particle does not change and the physical quantities do not depend on an additional variable S, then the electromagnetic and gravitational fields exist independently of each other. But if the rest mass is variable and there is a dependence on S, then these two fields are combined into a single unified field. In the extended space model a photon can have a nonzero mass and this mass can be either positive or negative. The gravitational effects such as the speed of escape, gravitational red shift and detection of light can be analyzed in the frame of the extended space model. In this model all these gravitational effects can be found algebraically by the rotations in the (1+4) dimensional space. Now it becomes possible to predict some future results of visible size of supermassive objects in our Universe due to new stage of experimental astronomy development in the RadioAstron Project and analyze phenomena is an explosion of the star V838 Mon.
Data surrounding the needs of human disease and toxicity modeling are largely siloed limiting the ability to extend and reuse modules across knowledge domains. Using an infrastructure that supports integration across knowledge domains (animal toxicology, high-throughput screening...
A Comprehensive X-Ray Absorption Model for Atomic Oxygen
Gorzyca, T.W.; Bautista, M.A.; Hasoglu, M.F.; García, J.; Gatuzz, E.; Kaastra, J.S.; Kallman, T.R.; Manson, S.T.; Mendoza, C.; Raassen, A.J.J.; de Vries, C.P.; Zatsarinny, O.
2013-01-01
An analytical formula is developed to accurately represent the photoabsorption cross section of O I for all energies of interest in X-ray spectral modeling. In the vicinity of the K edge, a Rydberg series expression is used to fit R-matrix results, including important orbital relaxation effects,
Comprehensive X-Ray Absorption Models for Oxygen and Neon
Gorczyca, Thomas
2013-09-01
We propose to perform state-of-the-art R-matrix calculations for the oxygen and neon photoabsorption cross sections to improve upon earlier, incomplete data. Several important higher-order effects will be addressed: orbital relaxation, Auger line broadening, two-electron shake, and elimination of pseudoresonances. The computed atomic cross sections will first be fit by a recently-developed analytical fitting formula, and then benchmarked further to experimental and Chandra observed absorption lines. The resulting data will be uploaded into the AtomDB, XSPEC, and ISIS databases for spectral modeling use. These definitive cross sections will resolve an outstanding discrepancy between XSTAR and SPEX spectral modeling predictions of molecular (dust and/or ice) abundances in the ISM.
A Comprehensive Numerical Model for Simulating Fluid Transport in Nanopores
Zhang, Yuan; Yu, Wei; Sepehrnoori, Kamy; di, Yuan
2017-01-01
Since a large amount of nanopores exist in tight oil reservoirs, fluid transport in nanopores is complex due to large capillary pressure. Recent studies only focus on the effect of nanopore confinement on single-well performance with simple planar fractures in tight oil reservoirs. Its impacts on multi-well performance with complex fracture geometries have not been reported. In this study, a numerical model was developed to investigate the effect of confined phase behavior on cumulative oil and gas production of four horizontal wells with different fracture geometries. Its pore sizes were divided into five regions based on nanopore size distribution. Then, fluid properties were evaluated under different levels of capillary pressure using Peng-Robinson equation of state. Afterwards, an efficient approach of Embedded Discrete Fracture Model (EDFM) was applied to explicitly model hydraulic and natural fractures in the reservoirs. Finally, three fracture geometries, i.e. non-planar hydraulic fractures, non-planar hydraulic fractures with one set natural fractures, and non-planar hydraulic fractures with two sets natural fractures, are evaluated. The multi-well performance with confined phase behavior is analyzed with permeabilities of 0.01 md and 0.1 md. This work improves the analysis of capillarity effect on multi-well performance with complex fracture geometries in tight oil reservoirs.
A Comprehensive X-Ray Absorption Model for Atomic Oxygen
Gorczyca, T. W.; Bautista, M. A.; Hasoglu, M. F.; Garcia, J.; Gatuzz, E.; Kaastra, J. S.; Kallman, T. R.; Manson, S. T.; Mendoza, C.; Raassen, A. J. J.;
2013-01-01
An analytical formula is developed to accurately represent the photoabsorption cross section of atomic Oxygen for all energies of interest in X-ray spectral modeling. In the vicinity of the K edge, a Rydberg series expression is used to fit R-matrix results, including important orbital relaxation effects, that accurately predict the absorption oscillator strengths below threshold and merge consistently and continuously to the above-threshold cross section. Further, minor adjustments are made to the threshold energies in order to reliably align the atomic Rydberg resonances after consideration of both experimental and observed line positions. At energies far below or above the K-edge region, the formulation is based on both outer- and inner-shell direct photoionization, including significant shake-up and shake-off processes that result in photoionization-excitation and double-photoionization contributions to the total cross section. The ultimate purpose for developing a definitive model for oxygen absorption is to resolve standing discrepancies between the astronomically observed and laboratory-measured line positions, and between the inferred atomic and molecular oxygen abundances in the interstellar medium from XSTAR and SPEX spectral models.
A comprehensive experimental and modeling study of 2-methylbutanol combustion
Park, Sungwoo
2015-05-01
2-Methylbutanol (2-methyl-1-butanol) is one of several next-generation biofuels that can be used as an alternative fuel or blending component for combustion engines. This paper presents new experimental data for 2-methylbutanol, including ignition delay times in a high-pressure shock tube and premixed laminar flame speeds in a constant volume combustion vessel. Shock tube ignition delay times were measured for 2-methylbutanol/air mixtures at three equivalence ratios, temperatures ranging from 750 to 1250. K, and at nominal pressures near 20 and 40. bar. Laminar flame speed data were obtained using the spherically propagating premixed flame configuration at pressures of 1, 2, and 5. bar. A detailed chemical kinetic model for 2-methylbutanol oxidation was developed including high- and low-temperature chemistry based on previous modeling studies on butanol and pentanol isomers. The proposed model was tested against new and existing experimental data at pressures of 1-40. atm, temperatures of 740-1636. K, equivalence ratios of 0.25-2.0. Reaction path and sensitivity analyses were conducted for identifying key reactions at various combustion conditions, and to obtain better understanding of the combustion characteristics of larger alcohols.
Model-Based Engine Control Architecture with an Extended Kalman Filter
Csank, Jeffrey T.; Connolly, Joseph W.
2016-01-01
This paper discusses the design and implementation of an extended Kalman filter (EKF) for model-based engine control (MBEC). Previously proposed MBEC architectures feature an optimal tuner Kalman Filter (OTKF) to produce estimates of both unmeasured engine parameters and estimates for the health of the engine. The success of this approach relies on the accuracy of the linear model and the ability of the optimal tuner to update its tuner estimates based on only a few sensors. Advances in computer processing are making it possible to replace the piece-wise linear model, developed off-line, with an on-board nonlinear model running in real-time. This will reduce the estimation errors associated with the linearization process, and is typically referred to as an extended Kalman filter. The nonlinear extended Kalman filter approach is applied to the Commercial Modular Aero-Propulsion System Simulation 40,000 (C-MAPSS40k) and compared to the previously proposed MBEC architecture. The results show that the EKF reduces the estimation error, especially during transient operation.
Extending the 4I Organizational Learning Model: Information Sources, Foraging Processes and Tools
Directory of Open Access Journals (Sweden)
Tracy A. Jenkin
2013-08-01
Full Text Available The continued importance of organizational learning has recently led to several calls for further developing the theory. This article addresses these calls by extending Crossan, Lane and White’s (1999 4I model to include a fifth process, information foraging, and a fourth level, the tool. The resulting 5I organizational learning model can be generalized to a number of learning contexts, especially those that involve understanding and making sense of data and information. Given the need for organizations to both innovate and increase productivity, and the volumes of data and information that are available to support both, the 5I model addresses an important organizational issue.
Comprehensive Analysis of Chicken Vessels as Microvascular Anastomosis Training Model
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Bo Young Kang
2017-01-01
Full Text Available BackgroundNonliving chickens are commonly used as a microvascular anastomosis training model. However, previous studies have investigated only a few types of vessel, and no study has compared the characteristics of the various vessels. The present study evaluated the anatomic characteristics of various chicken vessels as a training model.MethodsEight vessels—the brachial artery, basilic vein, radial artery, ulnar artery, ischiatic artery and vein, cranial tibial artery, and common dorsal metatarsal artery—were evaluated in 26 fresh chickens and 30 chicken feet for external diameter (ED and thicknesses of the tunica adventitia and media. The dissection time from skin incision to application of vessel clamps was also measured.ResultsThe EDs of the vessels varied. The ischiatic vein had the largest ED of 2.69±0.33 mm, followed by the basilic vein (1.88±0.36 mm, ischiatic artery (1.68±0.24 mm, common dorsal metatarsal artery (1.23±0.23 mm, cranial tibial artery (1.18±0.19 mm, brachial artery (1.08±0.15 mm, ulnar artery (0.82±0.13 mm, and radial artery (0.56±0.12 mm, and the order of size was consistent across all subjects. Thicknesses of the tunica adventitia and media were also diverse, ranging from 74.09±19.91 µm to 158.66±40.25 µm (adventitia and from 31.2±7.13 µm to 154.15±46.48 µm (media, respectively. Mean dissection time was <3 minutes for all vessels.ConclusionsOur results suggest that nonliving chickens can provide various vessels with different anatomic characteristics, which can allow trainees the choice of an appropriate microvascular anastomosis training model depending on their purpose and skillfulness.
Parametrization of contrails in a comprehensive climate model
Energy Technology Data Exchange (ETDEWEB)
Ponater, M.; Brinkop, S.; Sausen, R.; Schumann, U. [Deutsche Forschungs- und Versuchsanstalt fuer Luft- und Raumfahrt e.V., Oberpfaffenhofen (Germany). Inst. fuer Physik der Atmosphaere
1997-12-31
A contrail parametrization scheme for a general circulation model (GCM) is presented. Guidelines for its development were that it should be based on the thermodynamic theory of contrail formation and that it should be consistent with the cloud parametrization scheme of the GCM. Results of a six-year test integration indicate reasonable results concerning the spatial and temporal development of both contrail coverage and contrail optical properties. Hence, the scheme forms a promising basis for the quantitative estimation of the contrail climatic impact. (author) 9 refs.
Towards consistent nuclear models and comprehensive nuclear data evaluations
Energy Technology Data Exchange (ETDEWEB)
Bouland, O [Los Alamos National Laboratory; Hale, G M [Los Alamos National Laboratory; Lynn, J E [Los Alamos National Laboratory; Talou, P [Los Alamos National Laboratory; Bernard, D [FRANCE; Litaize, O [FRANCE; Noguere, G [FRANCE; De Saint Jean, C [FRANCE; Serot, O [FRANCE
2010-01-01
The essence of this paper is to enlighten the consistency achieved nowadays in nuclear data and uncertainties assessments in terms of compound nucleus reaction theory from neutron separation energy to continuum. Making the continuity of theories used in resolved (R-matrix theory), unresolved resonance (average R-matrix theory) and continuum (optical model) rangcs by the generalization of the so-called SPRT method, consistent average parameters are extracted from observed measurements and associated covariances are therefore calculated over the whole energy range. This paper recalls, in particular, recent advances on fission cross section calculations and is willing to suggest some hints for future developments.
CAN “THE IDEAL” ECONOMIC MODELS BE CONSIDERED COMPREHENSIBLE ?!
Directory of Open Access Journals (Sweden)
A.A. Kuklin
2006-03-01
Full Text Available This article opens the cycle of authors’ publications on the questions of theoretical approaches and representations of systems’ economics development. Digression of origin and development of social-economical formations is given. The attempt to consider the transformation of systems’ economics with the consideration of latent dynamic characteristics, to reveal the laws of structural-genetic and functional attribute of changing economy forming was made. Also it is offered to consider the models of systems’ economics transformation and their influence on territorial economic safety of different level.
FLS and FES: comprehensive models of training and assessment.
Vassiliou, Melina C; Dunkin, Brian J; Marks, Jeffrey M; Fried, Gerald M
2010-06-01
The Fundamentals of Laparoscopic surgery (FLS) is a validated program for the teaching and evaluation of the basic knowledge and skills required to perform laparoscopic surgery. The educational component includes didactic, Web-based material and a simple, affordable physical simulator with specific tasks and a recommended curriculum. FLS certification requires passing a written multiple-choice examination and a proctored manual skills examination in the FLS simulator. The metrics for the FLS program have been rigorously validated to meet the highest educational standards, and certification is now a requirement for the American Board of Surgery. This article summarizes the validation process and the FLS-related research that has been done to date. The Fundamentals of Endoscopic Surgery is a program modeled after FLS with a similar mission for flexible endoscopy. It is currently in the final stages of development and will be launched in April 2010. The program also includes learning and assessment components, and is undergoing the same meticulous validation process as FLS. These programs serve as models for the creation of simulation-based tools to teach skills and assess competence with the intention of optimizing patient safety and the quality of surgical education. Copyright 2010 Elsevier Inc. All rights reserved.
Bai, Ge; Luo, Li
2013-08-01
This investigation analyzes the management of medical schools merged with comprehensive universities through internet search and research review to reveal management model and effect of the merger. The conclusion is safely reached that governance models are divided into two different patterns: centralized management and decentralized management. Eight universities, representing the two models, were selected and evaluated comprehensively. Among them, the universities that carried out decentralized management have greater development after the merger based on a quality comparison concerning freshmen, faculty, teaching, and research between the two patterns. © 2013 Wiley Publishing Asia Pty Ltd and Chinese Cochrane Center, West China Hospital of Sichuan University.
Murthy, D N Prabhakar
2014-01-01
Serving to unify the existing literature on extended warranties, maintenance service contracts and lease contracts, this book also presents a unique perspective on the topic focussed on cost analysis and decision-making from the perspectives of the parties involved. Using a game theoretic approach together with mathematical modelling, results are presented in an integrated manner with key topics that require further research highlighted in order to serve as a starting point for researchers (engineers and statisticians) who are interested in doing further work in these areas. Designed to assist practitioners (managers, engineers, applied statisticians) who are involved with extended warranties, maintenance service contracts and lease contracts, the book provides them with the models and techniques needed for proper cost analysis and effective decision-making. The book is also suitable for use as a reference text in industrial engineering, applied statistics, operations research and management.
CSIR Research Space (South Africa)
Grobler, Inus
2013-09-01
Full Text Available Extended Conducted Electromagnetic Interference in Densely Packed DC- DC Converter I Grobler1 and MN Gitau2 Department of Electrical, Electronic and Computer Engineering, University of Pretoria, South Africa. igrobler@csir.co.za1, mgitau.... This will improve the overall design efficiency and shorten the crucial time to market period [1]. It is of utmost importance to try and model the electromagnetic compatibility concurrent with the power processor design stage. The marketplace is in need...
Juarez Collazo, N. A.; Wu, X.; Elen, J.; G. Clarebout
2014-01-01
This study adopts the Technology Acceptance Model (TAM) and extends it to study the effects of different variables on tool use. The influence of perceptions on tool use was studied in two different conditions: with and without explanation of the tool functionality. As an external variable, self-efficacy was entered in the TAM and the main research question thus focused on the mediating effects of perceptions (perceived tool functionality and perceived tool usability) between self-efficacy on ...
Valery Ivanovich ELFIMOV; Hamid KHAKZAD
2014-01-01
In this study, the performance of the extended shallow water model (ESWM) in evaluation of the flow regime of turbidity currents entering the Dez Reservoir was investigated. The continuity equations for fluid and particles and the Navier-Stokes equations govern the entire flow of turbidity currents. The shallow water equations governing the flow of the depositing phase of turbidity currents are derived from these equations. A case study was conducted on the flow regime of turbidity currents e...
Extended Holstein small polaron model for charge transfer in dry DNA.
Wang, Yi; Fu, Liang; Wang, Ke-Lin
2006-01-20
In this paper, the charge transfer problem in dry DNA was investigated by employing an extended Holstein small polaron model with external potential traps being involved in consideration. The ground state energy and the probability amplitude of polaron in various DNA chains with different external trap potentials were obtained by variational method with the trial function being taken in coherent state form. The stability of transfered charges in various circumstances was discussed accordingly.
Ward, Donald E.
1983-01-01
Describes models dealing with metatheory, group work, and client functioning level, and presents suggestions for integrating the models into a comprehensive system. A three-dimensional affective-cognitive-behavioral schema is suggested for guiding the selection of specific theories. (Author/JAC)
A Comprehensive Planning Model and Delivery System for Leadership Training Programs.
Janosik, Steven M.; Sina, Julie A.
1988-01-01
Presents an eight-step planning model that operationally defines a comprehensive delivery systems approach to campuswide leadership training. Lists four goals of the model: to increase efficiency of leadership training through shared resources, to decrease costs, to provide quality control, and to increase impact of programming effort by creating…
A Comprehensive Multi-Level Model for Campus-Based Leadership Education
Rosch, David; Spencer, Gayle L.; Hoag, Beth L.
2017-01-01
Within this application brief, we propose a comprehensive model for mapping the shape and optimizing the effectiveness of leadership education in campus-wide university settings. The four-level model is highlighted by inclusion of a philosophy statement detailing the values and purpose of leadership education on campus, a set of skills and…
Puerto Rico Univ., San Juan. School of Dentistry.
This annex supplements the Puerto Rico Experimental Model Dental Training Program Comprehensive Report (CE 028 213) and is comprised of exhibits A through F. Among the information included in the exhibits is the experimental model schedule, the schematic representation, the content display, and the course outlines for all courses in the program.…
Carlson, Abby G.; Curby, Timothy W.; Brown, Chavaughn A.; Trygstad, Kelly M.; Truong, Felicia R.
2017-01-01
The current study evaluates the effectiveness of a comprehensive instructional model, ("Every Child Ready"), as a vehicle to provide equitable education experiences for all children by compensating for gaps in teacher knowledge. The ECR instructional model addresses several challenges facing the early childhood landscape. Specifically,…
Karimi, Mehrnoosh; Hamzavi, Raouf
2017-01-01
The present study aimed at investigating the effect of flipped model of instruction on EFL learners' reading comprehension ability. Moreover, this study aimed at identifying EFL students' attitudes toward flipped model of instruction. To this end, 60 EFL learners studying at an accredited private language institute in Isfahan were first…
Charalambous, Charalambos; Kyriakides, Leonidas; Philippou, George
2003-01-01
The study reported in this paper is an attempt to develop a comprehensive model of measuring problem solving and posing (PSP) skills based on Marshall's schema theory (ST). A battery of tests on PSP skills was administered to 5th and 6th grade Cypriot students (n=2519). The Rasch model was used and a scale was created for the battery of tests and…
Quinn, Jamie M.; Wagner, Richard K.; Petscher, Yaacov; Lopez, Danielle
2015-01-01
The present study followed a sample of first-grade (N = 316, M[subscript age] = 7.05 at first test) through fourth-grade students to evaluate dynamic developmental relations between vocabulary knowledge and reading comprehension. Using latent change score modeling, competing models were fit to the repeated measurements of vocabulary knowledge and…
Laser-Plasma Modeling Using PERSEUS Extended-MHD Simulation Code for HED Plasmas
Hamlin, Nathaniel; Seyler, Charles
2017-10-01
We discuss the use of the PERSEUS extended-MHD simulation code for high-energy-density (HED) plasmas in modeling the influence of Hall and electron inertial physics on laser-plasma interactions. By formulating the extended-MHD equations as a relaxation system in which the current is semi-implicitly time-advanced using the Generalized Ohm's Law, PERSEUS enables modeling of extended-MHD phenomena (Hall and electron inertial physics) without the need to resolve the smallest electron time scales, which would otherwise be computationally prohibitive in HED plasma simulations. We first consider a laser-produced plasma plume pinched by an applied magnetic field parallel to the laser axis in axisymmetric cylindrical geometry, forming a conical shock structure and a jet above the flow convergence. The Hall term produces low-density outer plasma, a helical field structure, flow rotation, and field-aligned current, rendering the shock structure dispersive. We then model a laser-foil interaction by explicitly driving the oscillating laser fields, and examine the essential physics governing the interaction. This work is supported by the National Nuclear Security Administration stewardship sciences academic program under Department of Energy cooperative agreements DE-FOA-0001153 and DE-NA0001836.
Comprehensive model for predicting elemental composition of coal pyrolysis products
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Ricahrds, Andrew P. [Brigham Young Univ., Provo, UT (United States); Shutt, Tim [Brigham Young Univ., Provo, UT (United States); Fletcher, Thomas H. [Brigham Young Univ., Provo, UT (United States)
2017-04-23
Large-scale coal combustion simulations depend highly on the accuracy and utility of the physical submodels used to describe the various physical behaviors of the system. Coal combustion simulations depend on the particle physics to predict product compositions, temperatures, energy outputs, and other useful information. The focus of this paper is to improve the accuracy of devolatilization submodels, to be used in conjunction with other particle physics models. Many large simulations today rely on inaccurate assumptions about particle compositions, including that the volatiles that are released during pyrolysis are of the same elemental composition as the char particle. Another common assumption is that the char particle can be approximated by pure carbon. These assumptions will lead to inaccuracies in the overall simulation. There are many factors that influence pyrolysis product composition, including parent coal composition, pyrolysis conditions (including particle temperature history and heating rate), and others. All of these factors are incorporated into the correlations to predict the elemental composition of the major pyrolysis products, including coal tar, char, and light gases.
Energy Technology Data Exchange (ETDEWEB)
Ma, Jie; Wang, Bo [State Key Laboratory of Advanced Special Steel, Shanghai University, Shanghai 200072 (China); Shanghai Engineering Technology Research Center of Special Casting, Shanghai 201605 (China); Zhao, Shunli [Research Institute, Baoshan Iron & Steel Co., Ltd, Shanghai 201900 (China); Wu, Guangxin [State Key Laboratory of Advanced Special Steel, Shanghai University, Shanghai 200072 (China); Shanghai Engineering Technology Research Center of Special Casting, Shanghai 201605 (China); Zhang, Jieyu, E-mail: zjy6162@staff.shu.edu.cn [State Key Laboratory of Advanced Special Steel, Shanghai University, Shanghai 200072 (China); Shanghai Engineering Technology Research Center of Special Casting, Shanghai 201605 (China); Yang, Zhiliang [State Key Laboratory of Advanced Special Steel, Shanghai University, Shanghai 200072 (China); Shanghai Engineering Technology Research Center of Special Casting, Shanghai 201605 (China)
2016-05-25
We have extended the dendritic growth model first proposed by Boettinger, Coriell and Trivedi (here termed EBCT) for microstructure simulations of rapidly solidified non-dilute alloys. The temperature-dependent distribution coefficient, obtained from calculations of phase equilibria, and the continuous growth model (CGM) were adopted in the present EBCT model to describe the solute trapping behaviors. The temperature dependence of the physical properties, which were not used in previous dendritic growth models, were also considered in the present EBCT model. These extensions allow the present EBCT model to be used for microstructure simulations of non-dilute alloys. The comparison of the present EBCT model with the BCT model proves that the considerations of the distribution coefficient and physical properties are necessary for microstructure simulations, especially for small particles with high undercoolings. Finally, the EBCT model was incorporated into the cellular automaton-finite element (CAFE) model to simulate microstructures of gas-atomized ASP30 high speed steel particles that were then compared with experimental results. Both the simulated and experimental results reveal that a columnar dendritic microstructure preferentially forms in small particles and an equiaxed microstructure forms otherwise. The applications of the present EBCT model provide a convenient way to predict the microstructure of non-dilute alloys. - Highlights: • A dendritic growth model was developed considering non-equilibrium distribution coefficient. • The physical properties with temperature dependence were considered in the extended model. • The extended model can be used to non-dilute alloys and the extensions are necessary in small particles. • Microstructure of ASP30 steel was investigated using the present model and verified by experiment.
Yang, Shan-Shan; Pang, Ji-Wei; Guo, Wan-Qian; Yang, Xiao-Yin; Wu, Zhong-Yang; Ren, Nan-Qi; Zhao, Zhi-Qing
2017-05-01
This paper presents the results of an extended ASM2 model for the modeling and calibration of the role of extracellular polymeric substances (EPS) in phosphorus (P) removal in an anaerobic-aerobic process. In this extended ASM2 model, two new components, the bound EPS (XEPS) and the soluble EPS (SEPS), are introduced. Compared with the ASM2, 7.71, 8.53, and 9.28% decreases in polyphosphate (polyP) were observed in the extended ASM2 in three sequencing batch reactors feeding with different COD/P ratios, indicating that 7.71-9.28% of P in the liquid was adsorbed by EPS. Sensitive analysis indicated that, five parameters were the significant influential parameters and had been chosen for further model calibration by using the least square method to simulate by MATLAB. This extended ASM2 has been successfully established to simulate the output variables and provides a useful reference for the mathematic simulations of the role of EPS in biological phosphorus removal process. Copyright © 2017. Published by Elsevier Ltd.
Teo, Timothy
2016-01-01
The aim of this study is to examine the factors that influenced the use of Facebook among university students. Using an extended technology acceptance model (TAM) with emotional attachment (EA) as an external variable, a sample of 498 students from a public-funded Thailand university were surveyed on their responses to five variables hypothesized…
Multipartite quantum correlations in the extended J1-J2 Heisenberg model
Batle, J.; Tarawneh, O.; Nagata, Koji; Nakamura, Tadao; Abdalla, S.; Farouk, Ahmed
2017-11-01
Multipartite entanglement and the maximum violation of Bell inequalities are studied in finite clusters of spins in an extended J1-J2 Heisenberg model at zero temperature. The ensuing highly frustrated states will unveil a rich structure for different values of the corresponding spin-spin interaction strengths. The interplay between nearest-neighbors, next-nearest neighbors and further couplings will be explored using multipartite correlations. The model is relevant to certain quantum annealing computation architectures where an all-to-all connectivity is considered.
Doping driven metal-insulator transitions and charge orderings in the extended Hubbard model
Kapcia, K J; Capone, M; Amaricci, A
2016-01-01
We perform a thorough study of an extended Hubbard model featuring local and nearest-neighbor Coulomb repulsion. Using dynamical mean-field theory we investigated the zero temperature phase-diagram of this model as a function of the chemical doping. The interplay between local and non-local interaction drives a variety of phase-transitions connecting two distinct charge-ordered insulators, i.e., half-filled and quarter-filled, a charge-ordered metal and a Mott insulating phase. We characterize these transitions and the relative stability of the solutions and we show that the two interactions conspire to stabilize the quarter-filled charge ordered phase.
Luminosity variation in the extended one-zone RR Lyrae model
Directory of Open Access Journals (Sweden)
Pricopi D.
2005-01-01
Full Text Available The Stellingwerf one-zone stellar model is extended by assuming, a slow and uniform rotation that leads to a very small oblateness of the star. The matter in the core-surrounding shell is supposed to consists of a mixture of ideal gas and radiation. This one-zone stellar pulsation model is proposed as a tool to investigate the factors affecting luminosity variations of pulsating stars. Linear and nonlinear analyses of the resulting equations are described. The results are in very good agreement with the observed RR Lyrae light curves. .
Momentum Distribution Functions in a One-Dimensional Extended Periodic Anderson Model
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I. Hagymási
2015-01-01
Full Text Available We study the momentum distribution of the electrons in an extended periodic Anderson model, where the interaction, Ucf, between itinerant and localized electrons is taken into account. In the symmetric half-filled model, due to the increase of the interorbital interaction, the f electrons become more and more delocalized, while the itinerancy of conduction electrons decreases. Above a certain value of Ucf the f electrons become again localized together with the conduction electrons. In the less than half-filled case, we observe that Ucf causes strong correlations between the f electrons in the mixed valence regime.
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Shinya Ito
Full Text Available Transfer entropy (TE is an information-theoretic measure which has received recent attention in neuroscience for its potential to identify effective connectivity between neurons. Calculating TE for large ensembles of spiking neurons is computationally intensive, and has caused most investigators to probe neural interactions at only a single time delay and at a message length of only a single time bin. This is problematic, as synaptic delays between cortical neurons, for example, range from one to tens of milliseconds. In addition, neurons produce bursts of spikes spanning multiple time bins. To address these issues, here we introduce a free software package that allows TE to be measured at multiple delays and message lengths. To assess performance, we applied these extensions of TE to a spiking cortical network model (Izhikevich, 2006 with known connectivity and a range of synaptic delays. For comparison, we also investigated single-delay TE, at a message length of one bin (D1TE, and cross-correlation (CC methods. We found that D1TE could identify 36% of true connections when evaluated at a false positive rate of 1%. For extended versions of TE, this dramatically improved to 73% of true connections. In addition, the connections correctly identified by extended versions of TE accounted for 85% of the total synaptic weight in the network. Cross correlation methods generally performed more poorly than extended TE, but were useful when data length was short. A computational performance analysis demonstrated that the algorithm for extended TE, when used on currently available desktop computers, could extract effective connectivity from 1 hr recordings containing 200 neurons in ∼5 min. We conclude that extending TE to multiple delays and message lengths improves its ability to assess effective connectivity between spiking neurons. These extensions to TE soon could become practical tools for experimentalists who record hundreds of spiking neurons.
Ito, Shinya; Hansen, Michael E; Heiland, Randy; Lumsdaine, Andrew; Litke, Alan M; Beggs, John M
2011-01-01
Transfer entropy (TE) is an information-theoretic measure which has received recent attention in neuroscience for its potential to identify effective connectivity between neurons. Calculating TE for large ensembles of spiking neurons is computationally intensive, and has caused most investigators to probe neural interactions at only a single time delay and at a message length of only a single time bin. This is problematic, as synaptic delays between cortical neurons, for example, range from one to tens of milliseconds. In addition, neurons produce bursts of spikes spanning multiple time bins. To address these issues, here we introduce a free software package that allows TE to be measured at multiple delays and message lengths. To assess performance, we applied these extensions of TE to a spiking cortical network model (Izhikevich, 2006) with known connectivity and a range of synaptic delays. For comparison, we also investigated single-delay TE, at a message length of one bin (D1TE), and cross-correlation (CC) methods. We found that D1TE could identify 36% of true connections when evaluated at a false positive rate of 1%. For extended versions of TE, this dramatically improved to 73% of true connections. In addition, the connections correctly identified by extended versions of TE accounted for 85% of the total synaptic weight in the network. Cross correlation methods generally performed more poorly than extended TE, but were useful when data length was short. A computational performance analysis demonstrated that the algorithm for extended TE, when used on currently available desktop computers, could extract effective connectivity from 1 hr recordings containing 200 neurons in ∼5 min. We conclude that extending TE to multiple delays and message lengths improves its ability to assess effective connectivity between spiking neurons. These extensions to TE soon could become practical tools for experimentalists who record hundreds of spiking neurons.
Validating and extending the three process model of alertness in airline operations.
Directory of Open Access Journals (Sweden)
Michael Ingre
Full Text Available Sleepiness and fatigue are important risk factors in the transport sector and bio-mathematical sleepiness, sleep and fatigue modeling is increasingly becoming a valuable tool for assessing safety of work schedules and rosters in Fatigue Risk Management Systems (FRMS. The present study sought to validate the inner workings of one such model, Three Process Model (TPM, on aircrews and extend the model with functions to model jetlag and to directly assess the risk of any sleepiness level in any shift schedule or roster with and without knowledge of sleep timings. We collected sleep and sleepiness data from 136 aircrews in a real life situation by means of an application running on a handheld touch screen computer device (iPhone, iPod or iPad and used the TPM to predict sleepiness with varying level of complexity of model equations and data. The results based on multilevel linear and non-linear mixed effects models showed that the TPM predictions correlated with observed ratings of sleepiness, but explorative analyses suggest that the default model can be improved and reduced to include only two-processes (S+C, with adjusted phases of the circadian process based on a single question of circadian type. We also extended the model with a function to model jetlag acclimatization and with estimates of individual differences including reference limits accounting for 50%, 75% and 90% of the population as well as functions for predicting the probability of any level of sleepiness for ecological assessment of absolute and relative risk of sleepiness in shift systems for safety applications.
Validating and Extending the Three Process Model of Alertness in Airline Operations
Ingre, Michael; Van Leeuwen, Wessel; Klemets, Tomas; Ullvetter, Christer; Hough, Stephen; Kecklund, Göran; Karlsson, David; Åkerstedt, Torbjörn
2014-01-01
Sleepiness and fatigue are important risk factors in the transport sector and bio-mathematical sleepiness, sleep and fatigue modeling is increasingly becoming a valuable tool for assessing safety of work schedules and rosters in Fatigue Risk Management Systems (FRMS). The present study sought to validate the inner workings of one such model, Three Process Model (TPM), on aircrews and extend the model with functions to model jetlag and to directly assess the risk of any sleepiness level in any shift schedule or roster with and without knowledge of sleep timings. We collected sleep and sleepiness data from 136 aircrews in a real life situation by means of an application running on a handheld touch screen computer device (iPhone, iPod or iPad) and used the TPM to predict sleepiness with varying level of complexity of model equations and data. The results based on multilevel linear and non-linear mixed effects models showed that the TPM predictions correlated with observed ratings of sleepiness, but explorative analyses suggest that the default model can be improved and reduced to include only two-processes (S+C), with adjusted phases of the circadian process based on a single question of circadian type. We also extended the model with a function to model jetlag acclimatization and with estimates of individual differences including reference limits accounting for 50%, 75% and 90% of the population as well as functions for predicting the probability of any level of sleepiness for ecological assessment of absolute and relative risk of sleepiness in shift systems for safety applications. PMID:25329575
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Haigen Yang
2015-01-01
Full Text Available In order to accurately model the hysteresis and dynamic characteristics of piezoelectric stack actuators (PSAs, consider that a linear force and a hysteresis force will be generated by piezoelectric wafers under the voltage applied to a PSA, and the total force suffering from creep will result in the forced vibration of the two-degree-of-freedom mass-spring-damper system composed of the equivalent mass, stiffness, and damping of the piezoelectric wafers and the bonding layers. A modified comprehensive model for PSAs is put forward by using a linear function, an asymmetrical Bouc-Wen hysteresis operator, and a creep function to model the linear force, the hysteresis force, and the creep characteristics, respectively. In this way, the effect of the bonding layers on the hysteresis and dynamic characteristics of PSAs can be analyzed via the modified comprehensive model. The experimental results show that the modified comprehensive model for PSAs with the corresponding parameter identification method can accurately portray the hysteresis and dynamic characteristics of PSAs fabricated by different layering/stacking processes. Finally, the theoretical analyzing on utilizing the modified comprehensive model to linearize the hysteresis characteristics and design the dynamic characteristics of PSAs is given.
Pairwise-interaction extended point-particle model for particle-laden flows
Akiki, G.; Moore, W. C.; Balachandar, S.
2017-12-01
In this work we consider the pairwise interaction extended point-particle (PIEP) model for Euler-Lagrange simulations of particle-laden flows. By accounting for the precise location of neighbors the PIEP model goes beyond local particle volume fraction, and distinguishes the influence of upstream, downstream and laterally located neighbors. The two main ingredients of the PIEP model are (i) the undisturbed flow at any particle is evaluated as a superposition of the macroscale flow and a microscale flow that is approximated as a pairwise superposition of perturbation fields induced by each of the neighboring particles, and (ii) the forces and torque on the particle are then calculated from the undisturbed flow using the Faxén form of the force relation. The computational efficiency of the standard Euler-Lagrange approach is retained, since the microscale perturbation fields induced by a neighbor are pre-computed and stored as PIEP maps. Here we extend the PIEP force model of Akiki et al. [3] with a corresponding torque model to systematically include the effect of perturbation fields induced by the neighbors in evaluating the net torque. Also, we use DNS results from a uniform flow over two stationary spheres to further improve the PIEP force and torque models. We then test the PIEP model in three different sedimentation problems and compare the results against corresponding DNS to assess the accuracy of the PIEP model and improvement over the standard point-particle approach. In the case of two sedimenting spheres in a quiescent ambient the PIEP model is shown to capture the drafting-kissing-tumbling process. In cases of 5 and 80 sedimenting spheres a good agreement is obtained between the PIEP simulation and the DNS. For all three simulations, the DEM-PIEP was able to recreate, to a good extent, the results from the DNS, while requiring only a negligible fraction of the numerical resources required by the fully-resolved DNS.
Gu, Xiaojun; Zhang, Weihong; Zaki, Wael; Moumni, Ziad
2017-09-01
The model presented in this paper was shown to successfully account for cyclic loading effects and thermomechanical coupling in SMAs, including the influence of load rate and temperature on both the rate and value at saturation of the residual strain. It is the first such comprehensive model to be successfully utilized for relatively complex simulations involving SMAs subjected to multiaxial nonproportional loading, which possibly result in strong stress gradients such as fracture mechanics. In fact, it is known that the high stress concentration at the tip of a crack in SMAs results in increased martensite transformation and reorientation, which influence the growth of the crack. The derivation of the constitutive equations as well as the time integration and relevant algorithmic considerations are presented in detail. The model was shown to allow reasonable agreement with several sets of reference experimental and simulation data taken from the literature.
Energy Technology Data Exchange (ETDEWEB)
Glinsky, M.E.; Amendt, P.A.; Bailey, D.S.; London, R.A.; Rubenchik, A.M. [Lawrence Livermore National Lab., CA (United States); Strauss, M. [Israel Atomic Energy Commission, Beersheba (Israel). Nuclear Research Center-Negev
1997-03-04
The validity of an extended Rayleigh model for laser generated bubbles in soft tissue is examined. This model includes surface tension, viscosity, a realistic water equation of state, material strength and failure, stress wave emission, and linear growth of interface instabilities. It is compared to dynamic simulations using LATIS, which include stress wave propagation, water equation of state, material strength and failure, and viscosity. The model and the simulations are compared using 1-D spherical geometry with bubble in center and a 2-D cylindrical geometry of a laser fiber in water with a bubble formed at the end of the fiber. The model executes over 300x faster on computer than the dynamic simulations.
Double beta decay nuclear matrix elements in extended shell model spaces
Horoi, Mihai
2017-09-01
In a recent publication we concluded that the shell model double beta decay nuclear matrix elements may be affected to certain degrees by the lack of pairing correlations with orbitals outside the typical shell model spaces. Here we report results of calculations for 48Ca that includes 21 spherical orbitals for both protons and neutrons. We are using a realistic Hamiltonian inside the fp model space, thus maintaining a good description of the nuclear structure properties of the nuclei of interest. We are only allowing pairing interactions between the fp orbitals and the remaining 17 orbitals, and up to two particle excitations in and out of the fp model space. This approach could be also extended to the case of 82Se. Support from U.S. NSF Grant PHY-1404442 and DOE Grants DE-SC0008529 and DE-SC0015376 is acknowledged.
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Wenjun Huang
2017-01-01
Full Text Available Mechanical extending limit in horizontal drilling means the maximum horizontal extending length of a horizontal well under certain ground and down-hole mechanical constraint conditions. Around this concept, the constrained optimization model of mechanical extending limits is built and simplified analytical results for pick-up and slack-off operations are deduced. The horizontal extending limits for kinds of tubular strings under different drilling parameters are calculated and drawn. To improve extending limits, an optimal design model of drill strings is built and applied to a case study. The results indicate that horizontal extending limits are underestimated a lot when the effects of friction force on critical helical buckling loads are neglected. Horizontal extending limits firstly increase and tend to stable values with vertical depths. Horizontal extending limits increase faster but finally become smaller with the increase of horizontal pushing forces for tubular strings of smaller modulus-weight ratio. Sliding slack-off is the main limit operation and high axial friction is the main constraint factor constraining horizontal extending limits. A sophisticated installation of multiple tubular strings can greatly inhibit helical buckling and increase horizontal extending limits. The optimal design model is called only once to obtain design results, which greatly increases the calculation efficiency.
Low-dose rapamycin extends lifespan in a mouse model of mtDNA depletion syndrome.
Siegmund, Stephanie E; Yang, Hua; Sharma, Rohit; Javors, Martin; Skinner, Owen; Mootha, Vamsi; Hirano, Michio; Schon, Eric A
2017-12-01
Mitochondrial disorders affecting oxidative phosphorylation (OxPhos) are caused by mutations in both the nuclear and mitochondrial genomes. One promising candidate for treatment is the drug rapamycin, which has been shown to extend lifespan in multiple animal models, and which was previously shown to ameliorate mitochondrial disease in a knock-out mouse model lacking a nuclear-encoded gene specifying an OxPhos structural subunit (Ndufs4). In that model, relatively high-dose intraperitoneal rapamycin extended lifespan and improved markers of neurological disease, via an unknown mechanism. Here, we administered low-dose oral rapamycin to a knock-in (KI) mouse model of authentic mtDNA disease, specifically, progressive mtDNA depletion syndrome, resulting from a mutation in the mitochondrial nucleotide salvage enzyme thymidine kinase 2 (TK2). Importantly, low-dose oral rapamycin was sufficient to extend Tk2KI/KI mouse lifespan significantly, and did so in the absence of detectable improvements in mitochondrial dysfunction. We found no evidence that rapamycin increased survival by acting through canonical pathways, including mitochondrial autophagy. However, transcriptomics and metabolomics analyses uncovered systemic metabolic changes pointing to a potential 'rapamycin metabolic signature.' These changes also implied that rapamycin may have enabled the Tk2KI/KI mice to utilize alternative energy reserves, and possibly triggered indirect signaling events that modified mortality through developmental reprogramming. From a therapeutic standpoint, our results support the possibility that low-dose rapamycin, while not targeting the underlying mtDNA defect, could represent a crucial therapy for the treatment of mtDNA-driven, and some nuclear DNA-driven, mitochondrial diseases. © The Author 2017. Published by Oxford University Press.
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Fadare Oluwaseun Gbenga
2013-12-01
Full Text Available This paper examines various constructs of an extended TAM, Technology Acceptance Model, that are theoretically influencing the adoption and acceptability of mobile learning among 3G enabled mobile users. Mobile learning activity- based, used for this study were drawn from behaviourist and “learning and teaching support” educational paradigms. An online and manual survey instruments were used to gather data. The structural equation modelling techniques were then employed to explain the adoption processes of hypothesized research model. A theoretical model ETAM is developed based on TAM. Our result proved that psychometric constructs of TAM can be extended and that ETAM is well suited, and of good pedagogical tool in understanding mobile learning among 3G enabled handheld devices in southwest part of Nigeria. Cognitive constructs, attitude toward m-learning, self-efficacy play significant roles in influencing behavioural intention for mobile learning, of which self-efficacy is the most importance construct. Implications of results and directions for future research are discussed.
Building Models for Extended Radio Sources: Implications for Epoch of Reionisation Science
Trott, Cathryn M.; Wayth, Randall B.
2017-11-01
We test the hypothesis that limitations in the sky model used to calibrate an interferometric radio telescope, where the model contains extended radio sources, will generate bias in the Epoch of Reionisation power spectrum. The information contained in a calibration model about the spatial and spectral structure of an extended source is incomplete because a radio telescope cannot sample all Fourier components. Application of an incomplete sky model to calibration of Epoch of Reionisation data will imprint residual error in the data, which propagates forward to the Epoch of Reionisation power spectrum. This limited information is studied in the context of current and future planned instruments and surveys at Epoch of Reionisation frequencies, such as the Murchison Widefield Array (MWA), Giant Metrewave Radio Telescope and the Square Kilometre Array (SKA1-Low). For the MWA Epoch of Reionisation experiment, we find that both the additional short baseline uv-coverage of the compact Epoch of Reionisation array, and the additional long baselines provided by TGSS and planned MWA expansions, are required to obtain sufficient information on all relevant scales. For SKA1-Low, arrays with maximum baselines of 49 km and 65 km yield comparable performance at 50 MHz and 150 MHz, while 39 km, 14 km, and 4 km arrays yield degraded performance.
Renormalization group running of fermion observables in an extended non-supersymmetric SO(10) model
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Meloni, Davide [Dipartimento di Matematica e Fisica, Università di Roma Tre,Via della Vasca Navale 84, 00146 Rome (Italy); Ohlsson, Tommy; Riad, Stella [Department of Physics, School of Engineering Sciences,KTH Royal Institute of Technology - AlbaNova University Center,Roslagstullsbacken 21, 106 91 Stockholm (Sweden)
2017-03-08
We investigate the renormalization group evolution of fermion masses, mixings and quartic scalar Higgs self-couplings in an extended non-supersymmetric SO(10) model, where the Higgs sector contains the 10{sub H}, 120{sub H}, and 126{sub H} representations. The group SO(10) is spontaneously broken at the GUT scale to the Pati-Salam group and subsequently to the Standard Model (SM) at an intermediate scale M{sub I}. We explicitly take into account the effects of the change of gauge groups in the evolution. In particular, we derive the renormalization group equations for the different Yukawa couplings. We find that the computed physical fermion observables can be successfully matched to the experimental measured values at the electroweak scale. Using the same Yukawa couplings at the GUT scale, the measured values of the fermion observables cannot be reproduced with a SM-like evolution, leading to differences in the numerical values up to around 80%. Furthermore, a similar evolution can be performed for a minimal SO(10) model, where the Higgs sector consists of the 10{sub H} and 126{sub H} representations only, showing an equally good potential to describe the low-energy fermion observables. Finally, for both the extended and the minimal SO(10) models, we present predictions for the three Dirac and Majorana CP-violating phases as well as three effective neutrino mass parameters.
Low-lying Photoexcited States of a One-Dimensional Ionic Extended Hubbard Model
Yokoi, Kota; Maeshima, Nobuya; Hino, Ken-ichi
2017-10-01
We investigate the properties of low-lying photoexcited states of a one-dimensional (1D) ionic extended Hubbard model at half-filling. Numerical analysis by using the full and Lanczos diagonalization methods shows that, in the ionic phase, there exist low-lying photoexcited states below the charge transfer gap. As a result of comparison with numerical data for the 1D antiferromagnetic (AF) Heisenberg model, it was found that, for a small alternating potential Δ, these low-lying photoexcited states are spin excitations, which is consistent with a previous analytical study [Katsura et al., https://doi.org/10.1103/PhysRevLett.103.177402" xlink:type="simple">Phys. Rev. Lett. 103, 177402 (2009)]. As Δ increases, the spectral intensity of the 1D ionic extended Hubbard model rapidly deviates from that of the 1D AF Heisenberg model and it is clarified that this deviation is due to the neutral-ionic domain wall, an elementary excitation near the neutral-ionic transition point.
Ion gyroradius effects on zonal flows in extended Hasegawa-Mima models
Gallagher, Stephen; Hnat, Bogdan; Connaughton, Colm; Nazarenko, Sergey
2012-10-01
Zonal flows are important in fusion plasma where they regulate drift wave turbulence and improve plasma confinement. Two mechanisms can lead to the creation of zonal flows: an inverse cascade of energy, similar to that observed for 2D turbulence, and a coupling between wave modes known as the modulational instability. This work focused on the modulational instability; a four mode truncation of the extended Hasegawa-Mima system was derived to model this. The extended Hasegawa-Mima model is more appropriate for tokamaks than its predecessors as it decouples global flows from the flux surface averaged potential of the system. In addition to this truncated model a linearised set of equations for the system has been derived and used to produce a dispersion relation. Finite difference simulations of the whole system have been used to check these models. Previous work, which has largely considered the case where the ion gyroradius has been taken to its limits, has been expanded upon to show how the ion gyroradius can effect the behaviour of drift waves. It has been shown that the ion gyroradius can be used to change the strength of the nonlinearity of the system leading to changes in behaviour that have previously been demonstrated by altering the initial amplitude of the drift wave.
A 3-Factor Model Relating Communication to Risk Mitigation of Extended Information System Failover
Directory of Open Access Journals (Sweden)
Athanasios Podaras
2015-06-01
Full Text Available This paper aims to analyse the relation between timely and effective communication and risk mitigation of late recovery after an unexpected information system outage in enterprises. An unforeseen information system failure in modern enterprise units, may result to significant operational and financial damage. In such a critical incident, effective communication between the team leaders and the recovery team involved, can minimize or even eliminate this negative impact. An extended information system outage can be perceived as a time deviation from the Maximum Accepted Outage (ΜΑΟ timeframe, proposed by the business continuity management, according to the value of which dependent business functions may be interrupted without any serious effects to the company. The paper examines the relation between 3 basic factors and the efficient communication between team members. The factors are: timely information distribution, staff availability and network availability. Through the current paper, the author proposes a risk analysis model, based on the Composite Risk Index theory of Risk Management, which can significantly diminish the possibility of an extended information system outage, as well as calculate the extended time required to recover a system when the aforementioned factors emerge in their worst form. The precise calculation of recovery time can be achieved via the execution of business continuity tests which include scenarios, according to which an unexpected system outage coexists with delayed information distribution as well as low staff and network availability.
Proposal of Comprehensive Model of Teaching Basic Nursing Skills Under Goal-Based Scenario Theory.
Sannomiya, Yuri; Muranaka, Yoko; Teraoka, Misako; Suzuki, Sayuri; Saito, Yukie; Yamato, Hiromi; Ishii, Mariko
2016-01-01
The purpose of this study is to design and develop a comprehensive model of teaching basic nursing skills on GBS theory and Four-Stage Performance Cycle. We designed a basic nursing skill program that consists of three courses: basic, application and multi-tasking. The program will be offered as blended study, utilizing e-learning.
A Comprehensive Model of Career Development in Early Adulthood. Occasional Paper No. 12.
Crites, John O.
The paper proposes a comprehensive model of career development in early adulthood and addresses some of the theoretical and research issues central to furthering knowledge of how and why young adults enter and adjust to their jobs. The disciplines of vocational and organizational psychology, adjustment and developmental psychology, and industrial…
Vanberkel, Peter T.; Blake, J.T.
2008-01-01
This thesis describes the use of operational research techniques to analyze the wait list for the division of general surgery at the Capital District Health Authority (CDHA) in Halifax, Nova Scotia, Canada. A comprehensive simulation model was developed to facilitate capacity planning decisions and
Puerto Rico Univ., San Juan. School of Dentistry.
This annex supplements the Puerto Rico Experimental Model Dental Training Program Comprehensive Report (CE 028 213) and is comprised of exhibits G through L. Among the information included in the exhibits is the evaluation reports of the commission on accreditation, the detailed curriculum, and the accredited program's scope, sequence, and course…
Comprehension of Multiple Documents with Conflicting Information: A Two-Step Model of Validation
Richter, Tobias; Maier, Johanna
2017-01-01
In this article, we examine the cognitive processes that are involved when readers comprehend conflicting information in multiple texts. Starting from the notion of routine validation during comprehension, we argue that readers' prior beliefs may lead to a biased processing of conflicting information and a one-sided mental model of controversial…
Beyond Sexual Assault Surveys: A Model for Comprehensive Campus Climate Assessments
McMahon, Sarah; Stepleton, Kate; Cusano, Julia; O'Connor, Julia; Gandhi, Khushbu; McGinty, Felicia
2018-01-01
The White House Task Force to Protect Students from Sexual Assault identified campus climate surveys as "the first step" for addressing campus sexual violence. Through a process case study, this article presents one model for engaging in a comprehensive, action-focused campus climate assessment process. Rooted in principles of…
Zhang, Dongbo
2012-01-01
Using structural equation modeling analysis, this study examined the contribution of vocabulary and grammatical knowledge to second language reading comprehension among 190 advanced Chinese English as a foreign language learners. Vocabulary knowledge was measured in both breadth (Vocabulary Levels Test) and depth (Word Associates Test);…
Sun, Fengxin; Wang, Jufeng; Cheng, Rongjun; Ge, Hongxia
2018-02-01
The optimal driving speeds of the different vehicles may be different for the same headway. In the optimal velocity function of the optimal velocity (OV) model, the maximum speed vmax is an important parameter determining the optimal driving speed. A vehicle with higher maximum speed is more willing to drive faster than that with lower maximum speed in similar situation. By incorporating the anticipation driving behavior of relative velocity and mixed maximum speeds of different percentages into optimal velocity function, an extended heterogeneous car-following model is presented in this paper. The analytical linear stable condition for this extended heterogeneous traffic model is obtained by using linear stability theory. Numerical simulations are carried out to explore the complex phenomenon resulted from the cooperation between anticipation driving behavior and heterogeneous maximum speeds in the optimal velocity function. The analytical and numerical results all demonstrate that strengthening driver's anticipation effect can improve the stability of heterogeneous traffic flow, and increasing the lowest value in the mixed maximum speeds will result in more instability, but increasing the value or proportion of the part already having higher maximum speed will cause different stabilities at high or low traffic densities.
Crossover from reptation to Rouse dynamics in the extended Rubinstein-Duke model.
Drzewiński, Andrzej; van Leeuwen, J M J
2008-03-01
The competition between reptation and Rouse dynamics is incorporated in the Rubinstein-Duke model for polymer motion by extending it with sideways motions, which cross barriers and create or annihilate hernias. Using the density-matrix renormalization-group method as a solver of the master equation, the renewal time and the diffusion coefficient are calculated as functions of the length of the chain and the strength of the sideways motion. These types of moves have a strong and delicate influence on the asymptotic behavior of long polymers. The effects are analyzed as functions of the chain length in terms of effective exponents and crossover scaling functions.
White, Ronald J.; Leonard, Joel I.; Srinivasan, R. Srini; Charles, John B.
1991-01-01
The purpose of NASA's Extended Duration Orbiter program is a gradual extension of the capabilities of the Space Shuttle Orbiter beyond its current 7-10 day limit on mission duration, as warranted by deepening understanding of the long-term physiological effects of weightlessness. Attention is being given to the cardiovascular problem of orthostatic tolerance loss due to its adverse effects on crew performance and health during reentry and initial readaptation to earth gravity. An account is given of the results of the application of proven mathematical models of circulatory and cardiovascular systems under microgravity conditions.
Energy Technology Data Exchange (ETDEWEB)
Cuta, Judith M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Suffield, Sarah R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fort, James A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Adkins, Harold E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
2013-08-15
The work reported here is an investigation of the sensitivity of component temperatures of a storage system, including fuel cladding temperatures, in response to age-related changes that could degrade the design-basis thermal behavior of the system. The purpose of these sensitivity studies is to provide a realistic example of how changes in the physical properties or configuration of the storage system components can affect temperatures and temperature distributions. The magnitudes of these sensitivities can provide guidance for identifying appropriate modeling assumptions for thermal evaluations extending long term storage out beyond 50, 100, 200, and 300 years.
The extended clearance model and its use for the interpretation of hepatobiliary elimination data
Directory of Open Access Journals (Sweden)
Gian Camenisch
2015-03-01
Full Text Available Hepatic elimination is a function of the interplay between different processes such as sinusoidal uptake, intracellular metabolism, canalicular (biliary secretion, and sinusoidal efflux. In this review, we outline how drugs can be classified according to their in vitro determined clearance mechanisms using the extended clearance model as a reference. The approach enables the determination of the rate-determining hepatic clearance step. Some successful applications will be highlighted, together with a discussion on the major consequences for the pharmacokinetics and the drug-drug interaction potential of drugs. Special emphasize is put on the role of passive permeability and active transport processes in hepatic elimination.
EXTENDING THE DEEP PACKET INSPECTION MODEL TO THE GCC/MENA REGION
Directory of Open Access Journals (Sweden)
Alfred H. Miller
2013-12-01
Full Text Available This study seeks to explore extending the technology acceptance model (DPAM from a 2011 quantitative study—Modeling Intention to Use Deep Packet Inspection Technology in the United Arab Emirates, to the cyber security practitioner community of the Gulf Cooperation Council (GCC and greater Middle East North Africa (MENA Region. Analysis of regression between independent variable model factors of computer self efficacy, attitude toward ICT, perceived usefulness of ecommerce, intention to use ecommerce, societal trust and Internet filtration toward the dependent variable intention to use deep packet inspection, to determine parsimony, using confirmatory factor analysis (CFA, multinomial regression to assess correlation of independent and dependent variables, and assessment of the cross-suitability of DPAM across the MENA/GCC states through a MANOVA assessment. A qualitative component of the instrument enables collection of data about specific hardware and software deployed for deep packet inspection and cyber security systems.
Extended soft wall model with background related to features of QCD thermodynamics
Energy Technology Data Exchange (ETDEWEB)
Zoellner, R.; Kaempfer, B. [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); TU Dresden, Institut fuer Theoretische Physik, Dresden (Germany)
2017-06-15
The soft wall model is extended to accommodate at the same time i) approximately linear ρ meson Regge trajectories at zero temperature T, ii) various options for the thermodynamics with reference to QCD (cross-over or second-order transition or first-order transition at T{sub c}), and iii) the appearance of vector meson states at T
Liu, Kai; Balachandar, S.
2017-11-01
We perform a series of Euler-Lagrange direct numerical simulations (DNS) for multiphase jets and sedimenting particles. The forces the flow exerts on the particles in these two-way coupled simulations are computed using the Basset-Bousinesq-Oseen (BBO) equations. These forces do not explicitly account for particle-particle interactions, even though such pairwise interactions induced by the perturbations from neighboring particles may be important especially when the particle volume fraction is high. Such effects have been largely unaddressed in the literature. Here, we implement the Pairwise Interaction Extended Point-Particle (PIEP) model to simulate the effect of neighboring particle pairs. A simple collision model is also applied to avoid unphysical overlapping of solid spherical particles. The simulation results indicate that the PIEP model provides a more elaborative and complicated movement of the dispersed phase (droplets and particles). Office of Naval Research (ONR) Multidisciplinary University Research Initiative (MURI) project N00014-16-1-2617.
Extended Parker-Sochacki method for Michaelis-Menten enzymatic reaction model.
Abdelrazik, Ismail M; Elkaranshawy, Hesham A
2016-03-01
In this article, a new approach--namely, the extended Parker-Sochacki method (EPSM)--is presented for solving the Michaelis-Menten nonlinear enzymatic reaction model. The Parker-Sochacki method (PSM) is combined with a new resummation method called the Sumudu-Padé resummation method to obtain approximate analytical solutions for the model. The obtained solutions by the proposed approach are compared with the solutions of PSM and the Runge-Kutta numerical method (RKM). The comparison proves the practicality, efficiency, and correctness of the presented approach. It serves as a basis for solving other nonlinear biochemical reaction models in the future. Copyright © 2015 Elsevier Inc. All rights reserved.
The implementation of a comprehensive PBPK modeling approach resulted in ERDEM, a complex PBPK modeling system. ERDEM provides a scalable and user-friendly environment that enables researchers to focus on data input values rather than writing program code. ERDEM efficiently m...
In vitro 3-D model based on extending time of culture for studying chronological epidermis aging.
Dos Santos, Morgan; Metral, Elodie; Boher, Aurélie; Rousselle, Patricia; Thepot, Amélie; Damour, Odile
2015-09-01
Skin aging is a complex phenomenon in which several mechanisms operate simultaneously. Among them, intrinsic aging is a time-dependent process, which leads to gradual skin changes affecting its structure and function such as thinning down of both epidermal and dermal compartments and a flattening and fragility of the dermo-epidermal junction. Today, several approaches have been proposed for the generation of aged skin in vitro, including skin explants from aged donors and three-dimensional skin equivalent treated by aging-inducing chemical compounds or engineered with human cells isolated from aged donors. The aim of this study was to develop and validate a new in vitro model of aging based on skin equivalent demonstrating the same phenotypic changes that were observed in chronological aging. By using prolonged culture as a proxy for cellular aging, we extended to 120 days the culture time of a skin equivalent model based on collagen-glycosaminoglycan-chitosan porous polymer and engineered with human skin cells from photo-protected sites of young donors. Morphological, immunohistological and ultrastructural analysis at different time points of the culture allowed characterizing the phenotypic changes observed in our model in comparison to samples of non photo-exposed normal human skin from different ages. We firstly confirmed that long-term cultured skin equivalents are still morphologically consistent and functionally active even after 120 days of culture. However, similar to in vivo chronological skin aging a significant decrease of the epidermis thickness as well as the number of keratinocyte expressing proliferation marker Ki67 are observed in extended culture time skin equivalent. Epidermal differentiation markers loricrin, filaggrin, involucrin and transglutaminase, also strongly decreased. Ultrastructural analysis of basement membrane showed typical features of aged skin such as duplication of lamina densa and alterations of hemidesmosomes. Moreover, the
An Extended Non-Lane-Based Optimal Velocity Model with Dynamic Collaboration
Directory of Open Access Journals (Sweden)
Zhipeng Li
2013-01-01
Full Text Available Incorporating the effects of the lane width in traffic, in this paper, we propose a dynamical model based on the strategy of three-vehicle cooperation driving. We obtain the smoother acceleration distribution in the new model through considering the dynamic collaboration with the nearest preceding vehicle and the nearest following vehicle. It is proved that the stability of the new model is greatly improved compared to the early non-lane-based car following model by using the linear stability theory. We find that when the parameter of lateral separation distance is identified, the amplitude of traffic congestion decreases with increasing the strength of dynamic collaboration in the simulation experiments. In addition, we apply the new extended model to simulate the motions of cars starting from a traffic signal and the dissipating of the traffic congestion; it is found that our new model can predict realistic delay time and kinematic wave speed and obtained a faster dissipation speed of traffic congestion than the traffic flow model without considering the dynamic collaboration.
Hund, S J; Antaki, J F
2011-01-01
Transport phenomena of platelets and white blood cells (WBCs) are fundamental to the processes of vascular disease and thrombosis. Unfortunately, the dilute volume occupied by these cells is not amenable to fluid-continuum modeling, and yet the cell count is large enough that modeling each individual cell is impractical for most applications. The most feasible option is to treat them as dilute species governed by convection and diffusion; however, this is further complicated by the role of the red blood cell (RBC) phase on the transport of these cells. We therefore propose an extended convection–diffusion (ECD) model based on the diffusive balance of a fictitious field potential, Ψ, that accounts for the gradients of both the dilute phase and the local hematocrit. The ECD model was applied to the flow of blood in a tube and between parallel plates in which a profile for the RBC concentration field was imposed and the resulting platelet concentration field predicted. Compared to prevailing enhanced-diffusion models that dispersed the platelet concentration field, the ECD model was able to simulate a near-wall platelet excess, as observed experimentally. The extension of the ECD model depends only on the ability to prescribe the hematocrit distribution, and therefore may be applied to a wide variety of geometries to investigate platelet-mediated vascular disease and device-related thrombosis. PMID:19809124
Online Parameter Identification of Ultracapacitor Models Using the Extended Kalman Filter
Directory of Open Access Journals (Sweden)
Lei Zhang
2014-05-01
Full Text Available Ultracapacitors (UCs are the focus of increasing attention in electric vehicle and renewable energy system applications due to their excellent performance in terms of power density, efficiency, and lifespan. Modeling and parameterization of UCs play an important role in model-based regulation and management for a reliable and safe operation. In this paper, an equivalent circuit model template composed of a bulk capacitor, a second-order capacitance-resistance network, and a series resistance, is employed to represent the dynamics of UCs. The extended Kalman Filter is then used to recursively estimate the model parameters in the Dynamic Stress Test (DST on a specially established test rig. The DST loading profile is able to emulate the practical power sinking and sourcing of UCs in electric vehicles. In order to examine the accuracy of the identified model, a Hybrid Pulse Power Characterization test is carried out. The validation result demonstrates that the recursively calibrated model can precisely delineate the dynamic voltage behavior of UCs under the discrepant loading condition, and the online identification approach is thus capable of extracting the model parameters in a credible and robust manner.
Establishment of Comprehensive Evaluation Model of the New Generation Migrant Workers' Employability
GAO, Jianli; ZHANG, Tongquan
2013-01-01
Through literature research and expert interviews, we extract 10 variables influencing the new generation migrant workers' employability, and establish the comprehensive evaluation model of the new generation migrant workers' employability. Using factor analysis, we derive that the model includes three factors: skill literacy, relationship literacy and basic literacy. The weights of each factor are 0.580, 0.244 and 0.174 8, respectively. Skill literacy is affected by skill level, learning abi...
Ramos-Méndez, J.; Perl, J.; Schümann, J.; Shin, J.; Paganetti, H.; Faddegon, B.
2015-07-01
The aim of this work was to develop a framework for modeling organ effects within TOPAS (TOol for PArticle Simulation), a wrapper of the Geant4 Monte Carlo toolkit that facilitates particle therapy simulation. The DICOM interface for TOPAS was extended to permit contour input, used to assign voxels to organs. The following dose response models were implemented: The Lyman-Kutcher-Burman model, the critical element model, the population based critical volume model, the parallel-serial model, a sigmoid-based model of Niemierko for normal tissue complication probability and tumor control probability (TCP), and a Poisson-based model for TCP. The framework allows easy manipulation of the parameters of these models and the implementation of other models. As part of the verification, results for the parallel-serial and Poisson model for x-ray irradiation of a water phantom were compared to data from the AAPM Task Group 166. When using the task group dose-volume histograms (DVHs), results were found to be sensitive to the number of points in the DVH, with differences up to 2.4%, some of which are attributable to differences between the implemented models. New results are given with the point spacing specified. When using Monte Carlo calculations with TOPAS, despite the relatively good match to the published DVH’s, differences up to 9% were found for the parallel-serial model (for a maximum DVH difference of 2%) and up to 0.5% for the Poisson model (for a maximum DVH difference of 0.5%). However, differences of 74.5% (in Rectangle1), 34.8% (in PTV) and 52.1% (in Triangle) for the critical element, critical volume and the sigmoid-based models were found respectively. We propose a new benchmark for verification of organ effect models in proton therapy. The benchmark consists of customized structures in the spread out Bragg peak plateau, normal tissue, tumor, penumbra and in the distal region. The DVH’s, DVH point spacing, and results of the organ effect models are provided
A COMPREHENSIVE MODEL FOR THE POWER TRANSFORMER DIGITAL DIFFERENTIAL PROTECTION FUNCTIONING RESEARCH
Directory of Open Access Journals (Sweden)
Yu. V. Rumiantsev
2016-01-01
Full Text Available This article presents a comprehensive model for the two-winding power transformer digital differential protection functioning research. Considered comprehensive model is developed in MatLab-Simulink dynamic simulation environment with the help of SimPowerSystems component library and includes the following elements: power supply, three-phase power transformer, wye-connected current transformers and two-winding power transformer digital differential protection model. Each element of the presented model is described in the degree sufficient for its implementation in the dynamic simulation environment. Particular attention is paid to the digital signal processing principles and to the ways of differential and restraining currents forming of the considered comprehensive model main element – power transformer digital differential protection. With the help of this model the power transformer digital differential protection functioning was researched during internal and external faults: internal short-circuit, external short-circuit with and without current transformers saturation on the power transformer low-voltage side. Each experiment is illustrated with differential and restraining currents waveforms of the digital differential protection under research. Particular attention was paid to the digital protection functioning analysis during power transformer abnormal modes: overexcitation and inrush current condition. Typical current waveforms during these modes were showed and their harmonic content was investigated. The causes of these modes were analyzed in details. Digital differential protection blocking algorithms based on the harmonic content were considered. Drawbacks of theses algorithms were observed and the need of their further technical improvement was marked.
Directory of Open Access Journals (Sweden)
Rawid Banchuin
2014-01-01
Full Text Available In this research, the analysis of statistical variations in subthreshold MOSFET's high frequency characteristics defined in terms of gate capacitance and transition frequency, have been shown and the resulting comprehensive analytical models of such variations in terms of their variances have been proposed. Major imperfection in the physical level properties including random dopant fluctuation and effects of variations in MOSFET's manufacturing process, have been taken into account in the proposed analysis and modeling. The up to dated comprehensive analytical model of statistical variation in MOSFET's parameter has been used as the basis of analysis and modeling. The resulting models have been found to be both analytic and comprehensive as they are the precise mathematical expressions in terms of physical level variables of MOSFET. Furthermore, they have been verified at the nanometer level by using 65~nm level BSIM4 based benchmarks and have been found to be very accurate with smaller than 5 % average percentages of errors. Hence, the performed analysis gives the resulting models which have been found to be the potential mathematical tool for the statistical and variability aware analysis and design of subthreshold MOSFET based VHF circuits, systems and applications.
White, Ronald J.; Leonard, Joel I.; Srinivasan, R. Srini; Charles, John B.
The Extended Duration Orbiter (EDO) program aims to extend the capability of the Shuttle orbiter beyond its current 7-10 day limit on mission duration. This goal is to be accomplished in steps, partly due to our limited knowledge of the physiological changes resulting from long-term exposure to weightlessness and their likely influence on critical mission operations involved in EDO flights. Answers to questions related to physiologic adaptation to weightlessness are being actively sought at the present time to help implement the EDO program. In the cardiovascular area, the loss of orthostatic tolerance is a medical concern because of its potential adverse effects on crew performance and safety during reentry and following return to earth. Flight and ground-based physiologic studies are being planned to understand the mechanism and time course of spaceflight-induced orthostatic intolerance and to develop effective countermeasures for improving post-flight cardiovascular performance. Where feasible, these studies are aided by theoretical analyses using mathematical modeling and computer simulation of physiological systems. This paper is concerned with the application of proven models of circulatory and cardiovascular systems in the analysis of chronic cardiovascular changes under weightless conditions.
Akman, Ibrahim; Turhan, Cigdem
2017-01-01
This study aims to explore the users' behaviour and acceptance of social media for learning in higher educational institutions with the help of the extended Technology Acceptance Model (TAM). TAM has been extended to investigate how ethical and security awareness of users affect the actual usage of social learning applications. For this purpose, a…
Sittig, D F
1999-01-01
Experts disagree on the parameters to use to identify the "best" serials within a scientific field. The author set out to develop an extension to Dhawan's journal selection model for ranking serials in any scientific field. Comparison of three different instantiations of Dhawan's model were used to rank thirty-four biomedical informatics serials. The first instantiation of Dhawan's model identified seven serials and divided them into two groups. The second instantiation of Dhawan's model identified twelve serials and separated them into two groups. Using fuzzy set theory the new extended model produced a rank ordered list of the top twelve biomedical informatics serials. Use of fuzzy set theory to assign set membership and combine data in Dhawan's journal selection model allows one to: (1) eliminate the need to determine arbitrary cutoff points for inclusion of serials within each of Dhawan's evaluation criteria categories, (2) combine data from disparate sources, and (3) obtain a rank-ordered list of the biomedical informatics serials rather than simply identifying a set of the "top" serials. Such a ranked list provides librarians and researchers alike with the information necessary to help them make their biomedical informatics serial selection decisions based on objective, quantifiable data.
Extended numerical modeling of impurity neoclassical transport in tokamak edge plasmas
Energy Technology Data Exchange (ETDEWEB)
Inoue, H.; Yamoto, S.; Hatayama, A. [Graduate School of Science and Technology, Keio University, Hiyoshi, Yokohama (Japan); Homma, Y. [Graduate School of Science and Technology, Keio University, Hiyoshi, Yokohama (Japan); Research Fellow of Japan Society for the Promotion of Science, Tokyo (Japan)
2016-08-15
Understanding of impurity transport in tokamaks is an important issue in order to reduce the impurity contamination in fusion core plasmas. Recently, a new kinetic numerical scheme of impurity classical/neoclassical transport has been developed. This numerical scheme makes it possible to include classical self-diffusion (CL SD), classical inward pinch (CL IWP), and classical temperature screening effect (CL TSE) of impurity ions. However, impurity neoclassical transport has been modeled only in the case where background plasmas are in the Pfirsch-Schluter (PS) regime. The purpose of this study is to extend our previous model to wider range of collisionality regimes, i.e., not only the PS regime, but also the plateau regime. As in the previous study, a kinetic model with Binary Collision Monte-Carlo Model (BMC) has been adopted. We focus on the modeling of the neoclassical self-diffusion (NC SD) and the neoclassical inward pinch (NC IWP). In order to simulate the neoclassical transport with the BCM, velocity distribution of background plasma ions has been modeled as a deformed Maxwell distribution which includes plasma density gradient. Some test simulations have been done. As for NC SD of impurity ions, our scheme reproduces the dependence on the collisionality parameter in wide range of collisionality regime. As for NC IWP, in cases where test impurity ions and background ions are in the PS and plateau regimes, parameter dependences have been reproduced. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
Top quark rare decays via loop-induced FCNC interactions in extended mirror fermion model
Directory of Open Access Journals (Sweden)
P.Q. Hung
2018-02-01
Full Text Available Flavor changing neutral current (FCNC interactions for a top quark t decays into Xq with X represents a neutral gauge or Higgs boson, and q a up- or charm-quark are highly suppressed in the Standard Model (SM due to the Glashow–Iliopoulos–Miami mechanism. Whilst current limits on the branching ratios of these processes have been established at the order of 10−4 from the Large Hadron Collider experiments, SM predictions are at least nine orders of magnitude below. In this work, we study some of these FCNC processes in the context of an extended mirror fermion model, originally proposed to implement the electroweak scale seesaw mechanism for non-sterile right-handed neutrinos. We show that one can probe the process t→Zc for a wide range of parameter space with branching ratios varying from 10−6 to 10−8, comparable with various new physics models including the general two Higgs doublet model with or without flavor violations at tree level, minimal supersymmetric standard model with or without R-parity, and extra dimension model.
Directory of Open Access Journals (Sweden)
Yu Hsing
2009-12-01
Full Text Available Extending the open-economy loanable funds model, this paper finds that more government deficit as a percentage of GDP does not lead to a higher government bond yield. In addition, a higher real Treasury bill rate, a higher expected inflation rate, a higher EU government bond yield, or an expected depreciation of the euro against the U.S. dollar would increase Slovenia’s long-term interest rate. The negative coefficient of the percentage change in real GDP is insignificant at the10% level. Applying the standard closed-economy or open-economy loanable funds model without including the world interest rate and the expected exchange rate, we find similar conclusions except that the positive coefficient of the ratio of the net capital inflow to GDP has a wrong sign and is insignificant at the 10% level.
Extended versus standard Holstein model: Results in two and three dimensions
Chandler, Carl J.; Marsiglio, F.
2014-09-01
We present numerically exact solutions to the problem of a single electron interacting through an extended interaction with optical phonons in two and three dimensions. Comparisons are made with results for the standard Holstein model and with perturbative approaches from both the weak coupling and strong coupling sides. We find, in agreement with earlier work, that the polaron effective mass increases (decreases) in the weak (strong) coupling regime, respectively. However, in two dimensions, the decrease in effective mass still results in too large an effective mass to be relevant in realistic models of normal metals. In three dimensions the decrease can be more relevant but exists only over a very limited range of coupling strengths.
Extending Lattice Discrete Particle Model of Concrete for Non-circular Aggregates
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M. Kamza
2016-09-01
Full Text Available In this paper, Lattice-Discrete Particle Model (LDPM of concrete has been extended in 2-D to account for the effect of non-circular aggregates. To this end, the flexible equation of super-ellipse is employed for generating aggregates in order to add the simulation possibility of a greater spectrum of aggregate samples in 2-D to lattice-Discrete particle Model. Alongside this extention, required procedures for the generation of aggregates, their packing in space, the determination of influencing region of each particle, the definition of interacting surfaces and computational points and the definition of strains are outlined. Finally, the effects of aggregates geometry on macro-scale compressive strength and softening curve and also cracking pattern of concrete under uniaxial compression are discussed.
Study on queueing behavior in pedestrian evacuation by extended cellular automata model
Hu, Jun; You, Lei; Zhang, Hong; Wei, Juan; Guo, Yangyong
2018-01-01
This paper proposes a pedestrian evacuation model for effective simulation of evacuation efficiency based on extended cellular automata. In the model, pedestrians' momentary transition probability to a target position is defined in terms of the floor field and queueing time, and the critical time is defined as the waiting time threshold in a queue. Queueing time and critical time are derived using Fractal Brownian Motion through analysis of pedestrian arrival characteristics. Simulations using the platform and actual evacuations were conducted to study the relationships among system evacuation time, average system velocity, pedestrian density, flow rate, and critical time. The results demonstrate that at low pedestrian density, evacuation efficiency can be improved through adoption of the shortest route strategy, and critical time has an inverse relationship with average system velocity. Conversely, at higher pedestrian densities, it is better to adopt the shortest queueing time strategy, and critical time is inversely related to flow rate.
Extended hidden Markov model for optimized segmentation of breast thermography images
Mahmoudzadeh, E.; Montazeri, M. A.; Zekri, M.; Sadri, S.
2015-09-01
Breast cancer is the most commonly diagnosed form of cancer in women. Thermography has been shown to provide an efficient screening modality for detecting breast cancer as it is able to detect small tumors and hence can lead to earlier diagnosis. This paper presents a novel extended hidden Markov model (EHMM), for optimized segmentation of breast thermogram for more effective image interpretation and easier analysis of Infrared (IR) thermal patterns. Competitive advantage of EHMM method refers to handling random sampling of the breast IR images with re-estimation of the model parameters. The performance of the algorithm is illustrated by applying EHMM segmentation method on the images of IUT_OPTIC database and compared with previously related methods. Simulation results indicate the remarkable capabilities of the proposed approach. It is worth noting that the presented algorithm is able to map semi hot regions into distinct areas and extract the regions of breast thermal images significantly, while the execution time is reduced.
An extended car-following model with consideration of speed guidance at intersections
Zhao, Jing; Li, Peng
2016-11-01
The main motivation of this paper is to analyze the influences of speed guidance strategies on the driving behaviors under four different traffic signalized conditions and to investigate an extended car-following model to explore how the speed guidance affects two different vehicle types that are intelligent vehicles and traditional vehicles during the phase-change periods. The numerical results show that the proposed model can qualitatively describe the impacts of the speed guidance strategies on vehicle's movement trail including the acceleration strategy, smooth braking strategy, and deceleration strategy. Moreover, the benefits of the speed guidance could be enhanced by lengthening the guiding space range, expanding permitted guiding speed range, and increasing the percentage of the intelligent vehicles.
The water-induced linear reduction gas diffusivity model extended to three pore regions
DEFF Research Database (Denmark)
Chamindu, Deepagoda; De Jonge, Lis Wollesen; Kawamoto, Ken
2015-01-01
gas diffusivity from moist to dry conditions across differently structured porous media, including narrow soil size fractions, perforated plastic blocks, fractured limestone, peaty soils, aggregated volcanic ash soils, and particulate substrates for Earth- or space-based applications. The new Cip......An existing gas diffusivity model developed originally for sieved, repacked soils was extended to characterize gas diffusion in differently structured soils and functional pore networks. A gas diffusivity-derived pore connectivity index was used as a measure of soil structure development....... Characterization of soil functional pore structure is an essential prerequisite to understand key gas transport processes in variably saturated soils in relation to soil ecosystems, climate, and environmental services. In this study, the water-induced linear reduction (WLR) soil gas diffusivity model originally...
Excited scalar and pseudoscalar mesons in the extended linear sigma model
Energy Technology Data Exchange (ETDEWEB)
Parganlija, Denis [Technische Universitaet Wien, Institut fuer Theoretische Physik, Vienna (Austria); Giacosa, Francesco [Jan Kochanowski University, Institute of Physics, Kielce (Poland); Johann Wolfgang Goethe-Universitaet, Institut fuer Theoretische Physik, Frankfurt am Main (Germany)
2017-07-15
We present an in-depth study of masses and decays of excited scalar and pseudoscalar anti qq states in the Extended Linear Sigma Model (eLSM). The model also contains ground-state scalar, pseudoscalar, vector and axial-vector mesons. The main objective is to study the consequences of the hypothesis that the f{sub 0}(1790) resonance, observed a decade ago by the BES Collaboration and recently by LHCb, represents an excited scalar quarkonium. In addition we also analyse the possibility that the new a{sub 0}(1950) resonance, observed recently by BABAR, may also be an excited scalar state. Both hypotheses receive justification in our approach although there appears to be some tension between the simultaneous interpretation of f{sub 0}(1790)/a{sub 0}(1950) and pseudoscalar mesons η(1295), π(1300), η(1440) and K(1460) as excited anti qq states. (orig.)
Decays of open charmed mesons in the extended Linear Sigma Model
Directory of Open Access Journals (Sweden)
Eshraim Walaa I.
2014-01-01
Full Text Available We enlarge the so-called extended linear Sigma model (eLSM by including the charm quark according to the global U(4r × U(4l chiral symmetry. In the eLSM, besides scalar and pseudoscalar mesons, also vector and axial-vector mesons are present. Almost all the parameters of the model were fixed in a previous study of mesons below 2 GeV. In the extension to the four-flavor case, only three additional parameters (all of them related to the bare mass of the charm quark appear.We compute the (OZI dominant strong decays of open charmed mesons. The results are compatible with the experimental data, although the theoretical uncertainties are still large.
Kuang, Hua; Xu, Zhi-Peng; Li, Xing-Li; Lo, Siu-Ming
2017-04-01
In this paper, an extended car-following model is proposed to simulate traffic flow by considering average headway of preceding vehicles group in intelligent transportation systems environment. The stability condition of this model is obtained by using the linear stability analysis. The phase diagram can be divided into three regions classified as the stable, the metastable and the unstable ones. The theoretical result shows that the average headway plays an important role in improving the stabilization of traffic system. The mKdV equation near the critical point is derived to describe the evolution properties of traffic density waves by applying the reductive perturbation method. Furthermore, through the simulation of space-time evolution of the vehicle headway, it is shown that the traffic jam can be suppressed efficiently with taking into account the average headway effect, and the analytical result is consistent with the simulation one.
Parametric study of extended end-plate connection using finite element modeling
Mureşan, Ioana Cristina; Bâlc, Roxana
2017-07-01
End-plate connections with preloaded high strength bolts represent a convenient, fast and accurate solution for beam-to-column joints. The behavior of framework joints build up with this type of connection are sensitive dependent on geometrical and material characteristics of the elements connected. This paper presents results of parametric analyses on the behavior of a bolted extended end-plate connection using finite element modeling program Abaqus. This connection was experimentally tested in the Laboratory of Faculty of Civil Engineering from Cluj-Napoca and the results are briefly reviewed in this paper. The numerical model of the studied connection was described in detail in [1] and provides data for this parametric study.
Modeling thermal responses in human subjects following extended exposure to radiofrequency energy
Directory of Open Access Journals (Sweden)
Foster Kenneth R
2004-02-01
Full Text Available Abstract Background This study examines the use of a simple thermoregulatory model for the human body exposed to extended (45 minute exposures to radiofrequency/microwave (RF/MW energy at different frequencies (100, 450, 2450 MHz and under different environmental conditions. The exposure levels were comparable to or above present limits for human exposure to RF energy. Methods We adapted a compartmental model for the human thermoregulatory system developed by Hardy and Stolwijk, adding power to the torso skin, fat, and muscle compartments to simulate exposure to RF energy. The model uses values for parameters for "standard man" that were originally determined by Hardy and Stolwijk, with no additional adjustment. The model predicts changes in core and skin temperatures, sweat rate, and changes in skin blood flow as a result of RF energy exposure. Results The model yielded remarkably good quantitative agreement between predicted and measured changes in skin and core temperatures, and qualitative agreement between predicted and measured changes in skin blood flow. The model considerably underpredicted the measured sweat rates. Conclusions The model, with previously determined parameter values, was successful in predicting major aspects of human thermoregulatory response to RF energy exposure over a wide frequency range, and at different environmental temperatures. The model was most successful in predicting changes in skin temperature, and it provides insights into the mechanisms by which the heat added to body by RF energy is dissipated to the environment. Several factors are discussed that may have contributed to the failure to account properly for sweat rate. Some features of the data, in particular heating of the legs and ankles during exposure at 100 MHz, would require a more complex model than that considered here.
A Predictive Model for Extended Postanesthesia Care Unit Length of Stay in Outpatient Surgeries.
Gabriel, Rodney A; Waterman, Ruth S; Kim, Jihoon; Ohno-Machado, Lucila
2017-05-01
A predictive model that can identify patients who are at an increased risk for prolonged postanesthesia care unit (PACU) stay could help optimize resource utilization and case sequencing. Although previous studies identified some predictors, there is not a model that only utilizes various patients demographic and comorbidities, that are already known preoperatively, and that may affect PACU length of stay for outpatient procedures requiring the care of an anesthesiologist. We collected data from 4151 patients at a single institution from 2014 to 2015. The data set was split into a training set (cases before 2015) and a test set (cases during 2015). Bootstrap samples were chosen (R = 1000 replicates) and a logistic regression model was built on the samples using a combined method of forward selection and backward elimination based on the Akaike Information Criterion. The trained model was applied to the test set. Model performance was evaluated with the area under the receiver operating characteristic (ROC) Curve (AUC) for discrimination and the Hosmer-Lemeshow (HL) test for goodness-of-fit. The final model had 5 predictor variables for prolonged PACU length of stay, which included the following: morbid obesity, hypertension, surgical specialty, primary anesthesia type, and scheduled case duration. The model had an AUC value of 0.754 (95% confidence interval 0.733-0.774) on the training set and 0.722 (95% confidence interval 0.698-0.747) on the test set, with no difference between the 2 ROC curves (P = .06). The model had good calibration for the data in both the training and test data set indicated by nonsignificant P values from the HL test (P = .211 and .719 for the training and test set, respectively). We developed a predictive model with excellent discrimination and goodness-of-fit that can help identify those at higher odds for extended PACU length of stay. This information may help optimize case-sequencing methodologies.
Extending rule-based methods to model molecular geometry and 3D model resolution.
Hoard, Brittany; Jacobson, Bruna; Manavi, Kasra; Tapia, Lydia
2016-08-01
Computational modeling is an important tool for the study of complex biochemical processes associated with cell signaling networks. However, it is challenging to simulate processes that involve hundreds of large molecules due to the high computational cost of such simulations. Rule-based modeling is a method that can be used to simulate these processes with reasonably low computational cost, but traditional rule-based modeling approaches do not include details of molecular geometry. The incorporation of geometry into biochemical models can more accurately capture details of these processes, and may lead to insights into how geometry affects the products that form. Furthermore, geometric rule-based modeling can be used to complement other computational methods that explicitly represent molecular geometry in order to quantify binding site accessibility and steric effects. We propose a novel implementation of rule-based modeling that encodes details of molecular geometry into the rules and binding rates. We demonstrate how rules are constructed according to the molecular curvature. We then perform a study of antigen-antibody aggregation using our proposed method. We simulate the binding of antibody complexes to binding regions of the shrimp allergen Pen a 1 using a previously developed 3D rigid-body Monte Carlo simulation, and we analyze the aggregate sizes. Then, using our novel approach, we optimize a rule-based model according to the geometry of the Pen a 1 molecule and the data from the Monte Carlo simulation. We use the distances between the binding regions of Pen a 1 to optimize the rules and binding rates. We perform this procedure for multiple conformations of Pen a 1 and analyze the impact of conformation and resolution on the optimal rule-based model. We find that the optimized rule-based models provide information about the average steric hindrance between binding regions and the probability that antibodies will bind to these regions. These optimized models
Dissecting jets and missing energy searches using n-body extended simplified models
Cohen, Timothy; Dolan, Matthew J.; El Hedri, Sonia; Hirschauer, James; Tran, Nhan; Whitbeck, Andrew
2016-08-01
Simplified Models are a useful way to characterize new physics scenarios for the LHC. Particle decays are often represented using non-renormalizable operators that involve the minimal number of fields required by symmetries. Generalizing to a wider class of decay operators allows one to model a variety of final states. This approach, which we dub the n-body extension of Simplified Models, provides a unifying treatment of the signal phase space resulting from a variety of signals. In this paper, we present the first application of this framework in the context of multijet plus missing energy searches. The main result of this work is a global performance study with the goal of identifying which set of observables yields the best discriminating power against the largest Standard Model backgrounds for a wide range of signal jet multiplicities. Our analysis compares combinations of one, two and three variables, placing emphasis on the enhanced sensitivity gain resulting from non-trivial correlations. Utilizing boosted decision trees, we compare and classify the performance of missing energy, energy scale and energy structure observables. We demonstrate that including an observable from each of these three classes is required to achieve optimal performance. This work additionally serves to establish the utility of n-body extended Simplified Models as a diagnostic for unpacking the relative merits of different search strategies, thereby motivating their application to new physics signatures beyond jets and missing energy.
Comprehensive Weighted Clique Degree Ranking Algorithms and Evolutionary Model of Complex Network
Directory of Open Access Journals (Sweden)
Xu Jie
2016-01-01
Full Text Available This paper analyses the degree ranking (DR algorithm, and proposes a new comprehensive weighted clique degree ranking (CWCDR algorithms for ranking importance of nodes in complex network. Simulation results show that CWCDR algorithms not only can overcome the limitation of degree ranking algorithm, but also can find important nodes in complex networks more precisely and effectively. To the shortage of small-world model and BA model, this paper proposes an evolutionary model of complex network based on CWCDR algorithms, named CWCDR model. Simulation results show that the CWCDR model accords with power-law distribution. And compare with the BA model, this model has better average shortest path length, and clustering coefficient. Therefore, the CWCDR model is more consistent with the real network.
Epistemic beliefs as predictors of epistemic emotions: Extending a theoretical model.
Rosman, Tom; Mayer, Anne-Kathrin
2017-09-21
The cognitive incongruity model of epistemic beliefs and emotions states that if students' beliefs about the nature of knowledge (e.g., knowledge as simple and absolute) are incompatible with the epistemic nature of learning materials (e.g., complex and contradictory), cognitive incongruity arises. This, in turn, entails negative emotional consequences. The epistemic nature of contradictory learning materials might be perceived differently depending on whether individuals resolve the contradictions or not. Therefore, extending the cognitive incongruity model, the present paper argues that cognitive (in)congruity also depends on how individuals act on the learning materials. We expect that only if students resolve contradictory scientific claims (e.g., by identifying moderators), more advanced epistemic beliefs (e.g., evaluativism) have positive emotional effects and vice versa. A field-experimental study with N = 86 undergraduate psychology students was conducted. Using a multiple-texts approach, participants were first presented controversial evidence on gender stereotyping from 18 different (fictional) studies. In contrast to similar multiple-texts approaches, all contradictions could be resolved by identifying the contextual factors that a certain type of stereotype discrimination occurs in ('resolvable controversies'). After reading, the experimental group was asked to resolve the contradictions, whereas two control groups read the same texts, but were not required to resolve the controversies. Results revealed that absolute beliefs positively and evaluativistic beliefs negatively predict negative emotions, but only if students were instructed to resolve the contradictions. Our results suggest that extending the cognitive incongruity model by how students deal with controversial learning materials might be worthwhile. © 2017 The British Psychological Society.
Stuparu, Dana; Bachmann, Daniel; Bogaard, Tom; Twigt, Daniel; Verkade, Jan; de Bruijn, Karin; de Leeuw, Annemargreet
2017-04-01
Flood forecasts, warning and emergency response are important components in flood risk management. Most flood forecasting systems use models to translate weather predictions to forecasted discharges or water levels. However, this information is often not sufficient for real time decisions. A sound understanding of the reliability of embankments and flood dynamics is needed to react timely and reduce the negative effects of the flood. Where are the weak points in the dike system? When, how much and where the water will flow? When and where is the greatest impact expected? Model-based flood impact forecasting tries to answer these questions by adding new dimensions to the existing forecasting systems by providing forecasted information about: (a) the dike strength during the event (reliability), (b) the flood extent in case of an overflow or a dike failure (flood spread) and (c) the assets at risk (impacts). This work presents three study-cases in which such a set-up is applied. Special features are highlighted. Forecasting of dike strength. The first study-case focusses on the forecast of dike strength in the Netherlands for the river Rhine branches Waal, Nederrijn and IJssel. A so-called reliability transformation is used to translate the predicted water levels at selected dike sections into failure probabilities during a flood event. The reliability of a dike section is defined by fragility curves - a summary of the dike strength conditional to the water level. The reliability information enhances the emergency management and inspections of embankments. Ensemble forecasting. The second study-case shows the setup of a flood impact forecasting system in Dumfries, Scotland. The existing forecasting system is extended with a 2D flood spreading model in combination with the Delft-FIAT impact model. Ensemble forecasts are used to make use of the uncertainty in the precipitation forecasts, which is useful to quantify the certainty of a forecasted flood event. From global
Mass of a lattice polaron from an extended Holstein model using the Yukawa potential
Energy Technology Data Exchange (ETDEWEB)
Yavidov, B.Ya., E-mail: yavidov@inp.u [Institute of Nuclear Physics, 100214 Ulughbek, Tashkent (Uzbekistan); Djumanov, Sh.S.; Dzhumanov, S. [Institute of Nuclear Physics, 100214 Ulughbek, Tashkent (Uzbekistan)
2010-06-14
Renormalization of the mass of an electron is studied within the framework of the Extended Holstein model at strong coupling regime and nonadiabatic limit. In order to take into account an effect of screening of an electron-phonon interaction on a polaron it is assumed that the electron-phonon interaction potential has the Yukawa form and screening of the electron-phonon interaction is due to the presence of other electrons in a lattice. The forces are derived from the Yukawa type electron-phonon interaction potential. It is emphasized that the early considered screened force of (Kornilovitch (1998), Spencer et al. (2005), Hague et al. (2006), Hague and Kornilovitch (2009)) Refs. is a particular case of the force deduced from the Yukawa potential and is approximately valid at large screening radiuses compared to the distances under consideration. The Extended Holstein polaron with the Yukawa type potential is found to be a more mobile than polaron studied in early works at the same screening regime.
On the importance of comprehensible classification models for protein function prediction.
Freitas, Alex A; Wieser, Daniela C; Apweiler, Rolf
2010-01-01
The literature on protein function prediction is currently dominated by works aimed at maximizing predictive accuracy, ignoring the important issues of validation and interpretation of discovered knowledge, which can lead to new insights and hypotheses that are biologically meaningful and advance the understanding of protein functions by biologists. The overall goal of this paper is to critically evaluate this approach, offering a refreshing new perspective on this issue, focusing not only on predictive accuracy but also on the comprehensibility of the induced protein function prediction models. More specifically, this paper aims to offer two main contributions to the area of protein function prediction. First, it presents the case for discovering comprehensible protein function prediction models from data, discussing in detail the advantages of such models, namely, increasing the confidence of the biologist in the system's predictions, leading to new insights about the data and the formulation of new biological hypotheses, and detecting errors in the data. Second, it presents a critical review of the pros and cons of several different knowledge representations that can be used in order to support the discovery of comprehensible protein function prediction models.
Tighe, Elizabeth L.; Wagner, Richard K.; Schatschneider, Christopher
2015-01-01
This study demonstrates the utility of applying a causal indicator modeling framework to investigate important predictors of reading comprehension in third, seventh, and tenth grade students. The results indicated that a 4-factor multiple indicator multiple indicator cause (MIMIC) model of reading comprehension provided adequate fit at each grade…
Energy Technology Data Exchange (ETDEWEB)
Zhao, Haihua [Idaho National Laboratory; Zhang, Hongbin [Idaho National Laboratory; Zou, Ling [Idaho National Laboratory; Martineau, Richard Charles [Idaho National Laboratory
2015-03-01
The reactor core isolation cooling (RCIC) system in a boiling water reactor (BWR) provides makeup cooling water to the reactor pressure vessel (RPV) when the main steam lines are isolated and the normal supply of water to the reactor vessel is lost. The RCIC system operates independently of AC power, service air, or external cooling water systems. The only required external energy source is from the battery to maintain the logic circuits to control the opening and/or closure of valves in the RCIC systems in order to control the RPV water level by shutting down the RCIC pump to avoid overfilling the RPV and flooding the steam line to the RCIC turbine. It is generally considered in almost all the existing station black-out accidents (SBO) analyses that loss of the DC power would result in overfilling the steam line and allowing liquid water to flow into the RCIC turbine, where it is assumed that the turbine would then be disabled. This behavior, however, was not observed in the Fukushima Daiichi accidents, where the Unit 2 RCIC functioned without DC power for nearly three days. Therefore, more detailed mechanistic models for RCIC system components are needed to understand the extended SBO for BWRs. As part of the effort to develop the next generation reactor system safety analysis code RELAP-7, we have developed a strongly coupled RCIC system model, which consists of a turbine model, a pump model, a check valve model, a wet well model, and their coupling models. Unlike the traditional SBO simulations where mass flow rates are typically given in the input file through time dependent functions, the real mass flow rates through the turbine and the pump loops in our model are dynamically calculated according to conservation laws and turbine/pump operation curves. A simplified SBO demonstration RELAP-7 model with this RCIC model has been successfully developed. The demonstration model includes the major components for the primary system of a BWR, as well as the safety
Modeling of carbon dioxide absorption by aqueous ammonia solutions using the Extended UNIQUAC model
DEFF Research Database (Denmark)
Darde, Victor Camille Alfred; van Well, Willy J. M.; Stenby, Erling Halfdan
2010-01-01
ranges, enthalpy change from partial evaporation measurements, speciation data, heat capacity, enthalpy of solution and enthalpy of dilution data have been used to refit 43 model parameters and standard state properties. Henry’s law constant correlations have been used for extrapolating standard state...
Nonlinear reduced order models for fluids systems using extended dynamic mode decomposition
Dawson, Scott; Rowley, Clarence
2015-11-01
The development of techniques that can extract simple, accurate, and computationally tractable models from fluids data is of importance for enhanced prediction, control, and fundamental understanding of such systems. Modeling approaches can take the form of identifying modes upon which to project the governing equations (e.g., Galerkin projection onto a set of POD modes), or in determining (or calibrating) the temporal dynamics from data, such as in dynamic mode decomposition (DMD), or various modifications to Galerkin projection. Here, we demonstrate that choosing appropriate observables (such as linear and quadratic monomials of POD coefficients) can allow for nonlinear behavior to be accurately captured using the recently proposed extended DMD algorithm. For cylinder wake data spanning the transient and vortex shedding limit cycle regimes, the identified nonlinear models show significant improvement in accuracy and robustness over standard DMD and Galerkin projection. Compared to traditional DMD, this approach should also allow for a better global approximation of the Koopman operator for the dynamical system. We make connections with other related model identification algorithms, and additionally investigate the performance of the method upon spatially sparse and noisy data. This work was supported by the Air Force Office of Scientific Research, under award No. FA9550-12-1-0075.
Examining Mechanisms Underlying Fear-Control in the Extended Parallel Process Model.
Quick, Brian L; LaVoie, Nicole R; Reynolds-Tylus, Tobias; Martinez-Gonzalez, Andrea; Skurka, Chris
2017-01-17
This investigation sought to advance the extended parallel process model in important ways by testing associations among the strengths of efficacy and threat appeals with fear as well as two outcomes of fear-control processing, psychological reactance and message minimization. Within the context of print ads admonishing against noise-induced hearing loss (NIHL) and the fictitious Trepidosis virus, partial support was found for the additive model with no support for the multiplicative model. High efficacy appeals mitigated freedom threat perceptions across both contexts. Fear was positively associated with both freedom threat perceptions within the NIHL context and favorable attitudes for both NIHL and Trepidosis virus contexts. In line with psychological reactance theory, a freedom threat was positively associated with psychological reactance. Reactance, in turn, was positively associated with message minimization. The models supported reactance preceding message minimization across both message contexts. Both the theoretical and practical implications are discussed with an emphasis on future research opportunities within the fear-appeal literature.
Modelling waste stabilisation ponds with an extended version of ASM3.
Gehring, T; Silva, J D; Kehl, O; Castilhos, A B; Costa, R H R; Uhlenhut, F; Alex, J; Horn, H; Wichern, M
2010-01-01
In this paper an extended version of IWA's Activated Sludge Model No 3 (ASM3) was developed to simulate processes in waste stabilisation ponds (WSP). The model modifications included the integration of algae biomass and gas transfer processes for oxygen, carbon dioxide and ammonia depending on wind velocity and a simple ionic equilibrium. The model was applied to a pilot-scale WSP system operated in the city of Florianópolis (Brazil). The system was used to treat leachate from a municipal waste landfill. Mean influent concentrations to the facultative pond of 1,456 g(COD)/m(3) and 505 g(NH4-N)/m(3) were measured. Experimental results indicated an ammonia nitrogen removal of 89.5% with negligible rates of nitrification but intensive ammonia stripping to the atmosphere. Measured data was used in the simulations to consider the impact of wind velocity on oxygen input of 11.1 to 14.4 g(O2)/(m(2) d) and sun radiation on photosynthesis. Good results for pH and ammonia removal were achieved with mean stripping rates of 18.2 and 4.5 g(N)/(m(2) d) for the facultative and maturation pond respectively. Based on measured chlorophyll a concentrations and depending on light intensity and TSS concentration it was possible to model algae concentrations.
Higgs-Yukawa model with higher dimension operators via extended mean field theory
Akerlund, Oscar
2016-01-01
Using Extended Mean Field Theory (EMFT) on the lattice, we study properties of the Higgs-Yukawa model as an approximation of the Standard Model Higgs sector, and the effect of higher dimension operators. We note that the discussion of vacuum stability is completely modified in the presence of a $\\phi^6$ term, and that the Higgs mass no longer appears fine tuned. We also study the finite temperature transition. Without higher dimension operators the transition is found to be second order (crossover with gauge fields) for the experimental value of the Higgs mass $M_h=125$ GeV. By taking a $\\phi^6$ interaction in the Higgs potential as a proxy for a UV completion of the Standard Model, the transition becomes stronger and turns first order if the scale of new physics, i.e. the mass of the lightest mediator particle, is around $1.5$ TeV. This implies that electroweak baryogenesis may be viable in models which introduce new particles around that scale.
Spectral theory of extended Harper's model and a question by Erdős and Szekeres
Avila, A.; Jitomirskaya, S.; Marx, C. A.
2017-10-01
The extended Harper's model, proposed by D.J. Thouless in 1983, generalizes the famous almost Mathieu operator, allowing for a wider range of lattice geometries (parametrized by three coupling parameters) by permitting 2D electrons to hop to both nearest and next nearest neighboring (NNN) lattice sites, while still exhibiting its characteristic symmetry (Aubry duality). Previous understanding of the spectral theory of this model was restricted to two dual regions of the parameter space, one of which is characterized by the positivity of the Lyapunov exponent. In this paper, we complete the picture with a description of the spectral measures over the entire remaining (self-dual) region, for all irrational values of the frequency parameter (the magnetic flux in the model). Most notably, we prove that in the entire interior of this regime, the model exhibits a collapse from purely ac spectrum to purely sc spectrum when the NNN interaction becomes symmetric. In physics literature, extensive numerical analysis had indicated such "spectral collapse," however so far not even a heuristic argument for this phenomenon could be provided. On the other hand, in the remaining part of the self-dual region, the spectral measures are singular continuous irrespective of such symmetry. The analysis requires some rather delicate number theoretic estimates, which ultimately depend on the solution of a problem posed by Erd\\H{o}s and Szekeres.
Comprehensive Laser-induced Incandescence (LII) modeling for soot particle sizing
Lisanti, Joel
2015-03-30
To evaluate the current state of the art in LII particle sizing, a comprehensive model for predicting the temporal incandescent response of combustion-generated soot to absorption of a pulsed laser is presented. The model incorporates particle heating through laser absorption, thermal annealing, and oxidation at the surface as well as cooling through sublimation and photodesorption, radiation, conduction and thermionic emission. Thermodynamic properties and the thermal accommodation coefficient utilized in the model are temperature dependent. In addition, where appropriate properties are also phase dependent, thereby accounting for annealing effects during laser heating and particle cooling.
Costa, Rafael S; Hartmann, Andras; Gaspar, Paula; Neves, Ana R; Vinga, Susana
2014-03-04
Biomedical research and biotechnological production are greatly benefiting from the results provided by the development of dynamic models of microbial metabolism. Although several kinetic models of Lactococcus lactis (a Lactic Acid Bacterium (LAB) commonly used in the dairy industry) have been developed so far, most of them are simplified and focus only on specific metabolic pathways. Therefore, the application of mathematical models in the design of an engineering strategy for the production of industrially important products by L. lactis has been very limited. In this work, we extend the existing kinetic model of L. lactis central metabolism to include industrially relevant production pathways such as mannitol and 2,3-butanediol. In this way, we expect to study the dynamics of metabolite production and make predictive simulations in L. lactis. We used a system of ordinary differential equations (ODEs) with approximate Michaelis-Menten-like kinetics for each reaction, where the parameters were estimated from multivariate time-series metabolite concentrations obtained by our team through in vivo Nuclear Magnetic Resonance (NMR). The results show that the model captures observed transient dynamics when validated under a wide range of experimental conditions. Furthermore, we analyzed the model using global perturbations, which corroborate experimental evidence about metabolic responses upon enzymatic changes. These include that mannitol production is very sensitive to lactate dehydrogenase (LDH) in the wild type (W.T.) strain, and to mannitol phosphoenolpyruvate: a phosphotransferase system (PTS(Mtl)) in a LDH mutant strain. LDH reduction has also a positive control on 2,3-butanediol levels. Furthermore, it was found that overproduction of mannitol-1-phosphate dehydrogenase (MPD) in a LDH/PTS(Mtl) deficient strain can increase the mannitol levels. The results show that this model has prediction capability over new experimental conditions and offers promising
Extended Kinship in the United States: Competing Models and the Case of La Familia Chicana.
Sena-Rivera, Jaime
1979-01-01
Extended kinship among Chicanos is explored through intensive open-ended interviews with four cases of three generations of Mexican-descent families. "La familia chicana" is posited as a modified extended or kin-integrated family extending over time and space from Mexico at the turn of the century to present day industrial America. (Author)
Vowles, Kevin E; Sowden, Gail; Ashworth, Julie
2014-05-01
The therapeutic model underlying Acceptance and Commitment Therapy (ACT) is reasonably well-established as it applies to chronic pain. Several studies have examined measures of single ACT processes, or subsets of processes, and have almost uniformly indicated reliable relations with patient functioning. To date, however, no study has performed a comprehensive examination of the entire ACT model, including all of its component processes, as it relates to functioning. The present study performed this examination in 274 individuals with chronic pain presenting for an assessment appointment. Participants completed a battery of self-report questionnaires, assessing multiple aspects of the ACT model, as well as pain intensity, disability, and emotional distress. Initial exploratory factor analyses examined measures of the ACT model and measures of patient functioning separately with each analysis identifying three factors. Next, the fit of a model including ACT processes on the one hand and patient functioning on the other was examined using Structural Equation Modeling. Overall model fit was acceptable and indicated moderate correlations among the ACT processes themselves, as well as significant relations with pain intensity, emotional distress, and disability. These analyses build on the existing literature by providing, to our knowledge, the most comprehensive evaluation of the ACT theoretical model in chronic pain to date. Copyright © 2014. Published by Elsevier Ltd.
Directory of Open Access Journals (Sweden)
X. Huang
2016-03-01
Full Text Available New particle formation (NPF has been investigated intensively during the last 2 decades because of its influence on aerosol population and the possible contribution to cloud condensation nuclei. However, intensive measurements and modelling activities on this topic in urban metropolitan areas in China with frequent high-pollution episodes are still very limited. This study provides results from a comprehensive modelling study on the occurrence of NPF events in the western part of the Yangtze River Delta (YRD region, China. The comprehensive modelling system, which combines the WRF-Chem (the Weather Research and Forecasting model coupled with Chemistry regional chemical transport model and the MALTE-BOX sectional box model (the model to predict new aerosol formation in the lower troposphere, was shown to be capable of simulating atmospheric nucleation and subsequent growth. Here we present a detailed discussion of three typical NPF days, during which the measured air masses were notably influenced by either anthropogenic activities, biogenic emissions, or mixed ocean and continental sources. Overall, simulated NPF events were generally in good agreement with the corresponding measurements, enabling us to get further insights into NPF processes in the YRD region. Based on the simulations, we conclude that biogenic organic compounds, particularly monoterpenes, play an essential role in the initial condensational growth of newly formed clusters through their low-volatility oxidation products. Although some uncertainties remain in this modelling system, this method provides a possibility to better understand particle formation and growth processes.
Plasma contactor modeling with NASCAP/LEO - Extending laboratory results to space systems
Davis, V. A.; Katz, I.; Mandell, M. J.
1990-01-01
In the laboratory, hollow cathode-based plasma contactors have been observed to both emit and collect ampere-level electron currents with low impedance. The laboratory behavior of hollow cathode-based plasma contactors and the limited space experience with hollow cathodes suggest that, for many applications, a hollow cathode-based plasma contactor is the ideal device to provide electrical connection with the space plasma. In order to confidently extend the laboratory experience to the low-earth-orbit environment, a series of plasma contactor computer models has been developed. Calculations show that a hollow cathode plasma contactor that collects 0.5 A in the laboratory will only collect 2.4 mA in space. The simplest way to boost the collected current is to increase the gas flow. A mole of gas is enough to collect ampere level currents for 5-1/2 hours.
Feynman-Weinberg Quantum Gravity and the Extended Standard Model as a Theory of Everything
Tipler, Frank J
2005-01-01
I argue that the (extended) Standard Model (SM) of particle physics and the renormalizable Feynman-Weinberg theory of quantum gravity comprise a theory of everything. I show that imposing the appropriate cosmological boundary conditions make the theory finite. The infinities that are normally renormalized away and the series divergence infinities are both eliminated by the same mechanism. Furthermore, this theory can resolve the horizon, flatness, and isotropy problems of cosmology. Joint mathematical consistency naturally yields a scale-free, Gaussian, adiabatic perturbation spectrum, and more matter than antimatter. I show that mathematical consistency of the theory requires the universe to begin at an initial singularity with a pure $SU(2)_L$ gauge field. I show that quantum mechanics requires this field to have a Planckian spectrum whatever its temperature. If this field has managed to survive thermalization to the present day, then it would be the CMBR. If so, then we would have a natural explanation for...
Zhou, Kejin; Nguyen, Liem H; Miller, Jason B; Yan, Yunfeng; Kos, Petra; Xiong, Hu; Li, Lin; Hao, Jing; Minnig, Jonathan T; Zhu, Hao; Siegwart, Daniel J
2016-01-19
RNA-based cancer therapies are hindered by the lack of delivery vehicles that avoid cancer-induced organ dysfunction, which exacerbates carrier toxicity. We address this issue by reporting modular degradable dendrimers that achieve the required combination of high potency to tumors and low hepatotoxicity to provide a pronounced survival benefit in an aggressive genetic cancer model. More than 1,500 dendrimers were synthesized using sequential, orthogonal reactions where ester degradability was systematically integrated with chemically diversified cores, peripheries, and generations. A lead dendrimer, 5A2-SC8, provided a broad therapeutic window: identified as potent [EC50 75 mg/kg dendrimer repeated dosing). Delivery of let-7 g microRNA (miRNA) mimic inhibited tumor growth and dramatically extended survival. Efficacy stemmed from a combination of a small RNA with the dendrimer's own negligible toxicity, therefore illuminating an underappreciated complication in treating cancer with RNA-based drugs.
Nearest-Neighbor Repulsion and Competing Charge and Spin Order in the Extended Hubbard Model.
Bahman, Davoudi; Tremblay, A.-M. S.
2006-03-01
We generalize the Two-Particle Self-Consistent (TPSC) approach to study the extended Hubbard model where the nearest-neighbor interaction V is present in addition to the local interaction U. Our results are in good agreement with available Quantum Monte-Carlo results over the whole range of density n up to intermediate coupling. As a function of U, V and n we observe different kinds of charge and spin orders, like commensurate/incommensurate charge and spin density wave, phase separation, and ferromagnetic order. For attractive V superconductivity could exist in the regions where the other types of charge and spin orders do not dominate. Ref.: B. Davoudi and A.-M.S. Tremblay, cond-mat/0509707
Singlet exciton condensation and bond-order-wave phase in the extended Hubbard model
Hafez-Torbati, Mohsen; Uhrig, Götz S.
2017-09-01
The competition of interactions implies the compensation of standard mechanisms, which leads to the emergence of exotic phases between conventional phases. The extended Hubbard model (EHM) is a fundamental example for the competition of the local Hubbard interaction and the nearest-neighbor density-density interaction, which at half-filling and in one dimension leads to a bond-order wave (BOW) between a charge-density wave (CDW) and a quasi-long-range order Mott insulator. We study the full momentum-resolved excitation spectrum of the one-dimensional EHM in the CDW phase, and we clarify the relation between different elementary energy gaps. We show that the CDW-to-BOW transition is driven by the softening of a singlet exciton at momentum π . The BOW is realized as the condensate of this singlet exciton.
A Relevance-Extended Multi-dimensional Model for a Data Warehouse Contextualized with Documents
DEFF Research Database (Denmark)
Perez, Juan Manuel; Pedersen, Torben Bach; Berlanga, Rafael
2005-01-01
Current data warehouse and OLAP technologies can be applied to analyze the structured data that companies store in their databases. The circumstances that describe the context associated with these data can be found in other internal and external sources of documents. In this paper we propose...... to combine the traditional corporate data warehouse with a document warehouse, resulting in a contextualized warehouse. Thus, contextualized warehouses keep a historical record of the facts and their contexts as described by the documents. In this framework, the user selects an analysis context which...... with the documents that explain their circumstances. In this work we extend an existing multi-dimensional data model and algebra for representing the R-cubes....
When subgroups secede: extending and refining the social psychological model of schism in groups.
Sani, Fabio
2005-08-01
This article is about a field study (N=1,080) concerning the secession of a subgroup from the Church of England, and it is aimed at extending and refining the existing social psychological model of schisms in groups. It was found that the first step toward a schism is the belief that the group identity has been subverted. This belief will prompt negative emotions (i.e., dejection and agitation) and decrease both group identification and perceived group entitativity (i.e., cohesion, oneness). In turn, low group entitativity will reduce the level of group identification. Finally, low group identification and high negative emotions will increase schismatic intentions. It is also demonstrated that the negative impact of group identification, and the positive impact of negative emotions, on schismatic intentions is moderated by the perceived ability to voice dissent (i.e., the greater the perceived voice, the weaker the impact).
Process simulation of CO2 capture with aqueous ammonia using the Extended UNIQUAC model
DEFF Research Database (Denmark)
Darde, Victor Camille Alfred; Maribo-Mogensen, Bjørn; van Well, Willy J.M.
2012-01-01
The use of aqueous ammonia is a promising option to capture carbon dioxide from power plants thanks to the potential low heat requirement during the carbon dioxide desorption compared to monoethanolamine (MEA) based process. The patented Chilled Ammonia Process developed by Alstom absorbs carbon...... of the process is necessary.In this work, the performance of the carbon dioxide capture process using aqueous ammonia has been analyzed by process simulation. The Extended UNIQUAC thermodynamic model available for the CO2–NH3–H2O system has been implemented in the commercial simulator Aspen Plus®1 by using...... to be in the same range as the values reported recently for advanced amine processes. Assuming that cold cooling water is available, the electricity consumption remains limited. Hence the Chilled Ammonia Process is a promising option for post combustion carbon dioxide capture....
Extended Generalized-K (EGK): A New Simple and General Model for Composite Fading Channels
Yilmaz, Ferkan
2010-01-01
In this paper, we introduce a generalized composite fading distribution (termed extended generalized-K (EGK)) to model the envelope and the power of the received signal in millimeter wave (60 GHz or above) and free-space optical channels. We obtain the first and the second-order statistics of the received signal envelope characterized by the EGK composite fading distribution. In particular, expressions for probability density function, cumulative distribution function, level crossing rate and average fade duration, and fractional moments are derived. In addition performance measures such as amount of fading, average bit error probability, outage probability, average capacity, and outage capacity are offered in closed-form. Selected numerical and computer simulation examples validate the accuracy of the presented mathematical analysis.
Video Game Acceptance: A Meta-Analysis of the Extended Technology Acceptance Model.
Wang, Xiaohui; Goh, Dion Hoe-Lian
2017-11-01
The current study systematically reviews and summarizes the existing literature of game acceptance, identifies the core determinants, and evaluates the strength of the relationships in the extended technology acceptance model. Moreover, this study segments video games into two categories: hedonic and utilitarian and examines player acceptance of these two types separately. Through a meta-analysis of 50 articles, we find that perceived ease of use (PEOU), perceived usefulness (PU), and perceived enjoyment (PE) significantly associate with attitude and behavioral intention. PE is the dominant predictor of hedonic game acceptance, while PEOU and PU are the main determinants of utilitarian game acceptance. Furthermore, we find that respondent type and game platform are significant moderators. Findings of this study provide critical insights into the phenomenon of game acceptance and suggest directions for future research.
University staff adoption of iPads: An empirical study using an extended TAM model
Directory of Open Access Journals (Sweden)
Michael Steven Lane
2014-11-01
Full Text Available This research examined key factors influencing adoption of iPads by university staff. An online survey collected quantitative data to test hypothesised relationships in an extended TAM model. The findings show that university staff consider iPads easy to use and useful, with a high level of compatibility with their work. Social status had no influence on their attitude to using an iPad. However older university staff and university staff with no previous experience in using a similar technology such as an iPhone or smartphone found iPads less easy to use. Furthermore, a lack of formal end user ICT support impacted negatively on the use of iPads.
Archetype-Based Modeling of Persona for Comprehensive Personality Computing from Personal Big Data.
Guo, Ao; Ma, Jianhua
2018-02-25
A model describing the wide variety of human behaviours called personality, is becoming increasingly popular among researchers due to the widespread availability of personal big data generated from the use of prevalent digital devices, e.g., smartphones and wearables. Such an approach can be used to model an individual and even digitally clone a person, e.g., a Cyber-I (cyber individual). This work is aimed at establishing a unique and comprehensive description for an individual to mesh with various personalized services and applications. An extensive research literature on or related to psychological modelling exists, i.e., into automatic personality computing. However, the integrity and accuracy of the results from current automatic personality computing is insufficient for the elaborate modeling in Cyber-I due to an insufficient number of data sources. To reach a comprehensive psychological description of a person, it is critical to bring in heterogeneous data sources that could provide plenty of personal data, i.e., the physiological data, and the Internet data. In addition, instead of calculating personality traits from personal data directly, an approach to a personality model derived from the theories of Carl Gustav Jung is used to measure a human subject's persona. Therefore, this research is focused on designing an archetype-based modeling of persona covering an individual's facets in different situations to approach a comprehensive personality model. Using personal big data to measure a specific persona in a certain scenario, our research is designed to ensure the accuracy and integrity of the generated personality model.
Archetype-Based Modeling of Persona for Comprehensive Personality Computing from Personal Big Data
Directory of Open Access Journals (Sweden)
Ao Guo
2018-02-01
Full Text Available A model describing the wide variety of human behaviours called personality, is becoming increasingly popular among researchers due to the widespread availability of personal big data generated from the use of prevalent digital devices, e.g., smartphones and wearables. Such an approach can be used to model an individual and even digitally clone a person, e.g., a Cyber-I (cyber individual. This work is aimed at establishing a unique and comprehensive description for an individual to mesh with various personalized services and applications. An extensive research literature on or related to psychological modelling exists, i.e., into automatic personality computing. However, the integrity and accuracy of the results from current automatic personality computing is insufficient for the elaborate modeling in Cyber-I due to an insufficient number of data sources. To reach a comprehensive psychological description of a person, it is critical to bring in heterogeneous data sources that could provide plenty of personal data, i.e., the physiological data, and the Internet data. In addition, instead of calculating personality traits from personal data directly, an approach to a personality model derived from the theories of Carl Gustav Jung is used to measure a human subject’s persona. Therefore, this research is focused on designing an archetype-based modeling of persona covering an individual’s facets in different situations to approach a comprehensive personality model. Using personal big data to measure a specific persona in a certain scenario, our research is designed to ensure the accuracy and integrity of the generated personality model.
Use of the extended parallel processing model to evaluate culturally relevant kernicterus messages.
Russell, Jessica C; Smith, Sandi; Novales, Wilma; Massi Lindsey, Lisa L; Hanson, Joseph
2013-01-01
Kernicterus is a serious but easily preventable disease in newborns that is not well-known even by some health care professionals. This study evaluated a parent guide and poster on kernicterus awareness and prevention generated by the Centers for Disease Control and Prevention. The extended parallel processing model was used as a framework for creating the interview protocol and analyzing the results. In-depth interviews were conducted with four parents and six health care personnel of different ethnicities to evaluate the materials. Content for the parent guide and poster was held constant, but photos were varied according to the ethnicity of the baby (white, African American, or Hispanic) and the language in which the interviews were conducted (English and Spanish). The parent guide was evaluated positively, but reactions to the poster were varied. The consensus was that the poster drew more attention than the pocket guide but lacked sufficient information about what jaundice is or how to treat it, while the pocket guide provided information, especially with regard to efficacy. The extended parallel processing model claims that when efficacy is equal to or higher than perceived threat, respondents should engage in recommended responses, which was the general finding from these interviews. Recommendations for improvements of the materials are presented. The focus on different ethnicities in the materials was perceived as unnecessary and potentially counter-productive. Both parents and health care professionals mentioned the lack of information regarding treatment. Providing information on the length and effectiveness of treatment for jaundice and kernicterus might increase efficacy in averting the threat in both conditions. Copyright © 2013 National Association of Pediatric Nurse Practitioners. Published by Mosby, Inc. All rights reserved.
Dansgaard Oeschger Dynamics: Clearly Revealed in a Comprehensive Model of Glacial Climate
Peltier, W. Richard; Vettoretti, Guido
2017-04-01
More than 30 years ago, Willi Dansgaard in Copenhagen and Hans Oeschger in Bern established the existence of millennium timescale oscillations in oxygen isotope stratigraphies from Greenland ice cores. This isotopic signal was interpreted as implying large amplitude variations in surface air temperature. Until the publication of Peltier and Vettoretti (2014, GRL) the prevalent view had been that this exclusively ice-age phenomenon, thought to be linked to variability in the strength of the Atlantic MOC, was considered to be forced by the episodic release of freshwater from the continental ice sheets, each oscillation requiring its own freshwater input. In Peltier and Vettoretti (2014) this phenomenon was recovered for the first time in a comprehensive model of glacial climate, specifically the CESM1 model of the NCAR laboratory. Attention was drawn to the fact that individual D-O oscillations, or Bond Cycle clusters of such oscillations, were inevitably preceded by individual Heinrich events. In Peltier and Vettoretti (2014) it was shown that, following the "spin-up" of CESM1 into the glacial state, with continental ice sheet volume held fixed, a sequence of nonlinear unforced and therefor "free" oscillations of the MOC occurred, following a sharp Heinrich event-like sharp suppression of MOC strength. All of the salient characteristics of the D-O process inferred on the basis of ice core evidence from both hemispheres were fully captured in these high (CMIP5) resolution simulations, namely: (i) the pulse shape of the individual oscillations characterized by an extremely rapid shift from cold stadial to warm interstadial conditions followed by a slow return to the stadial state, (ii) the peak-to-peak variations in Greenland surface air temperature of 10-15 degrees Centigrade during individual oscillations, (iii) the "bi-polar see saw" connection between this Northern Hemisphere process and that recorded in the EDML and WAIS Divide ice cores from Antarctica, (iv) the
An Extended Global Sensitivity Analysis Implemented on a 1D Land Biosphere Model
Ioannou-Katidis, Pavlos; Petropoulos, George; Griffiths, Hywel; Bevan, Rhodri
2014-05-01
The implementation of sophisticated mathematical models is undoubtedly becoming increasingly widely used in a variety of fields in geosciences. SimSphere belongs to a special category of land biosphere models called Soil Vegetation Atmosphere Transfer (SVAT) models. Those provide representations, in a vertical profile, of the physical mechanisms controlling the physical interactions occurring in the soil/vegetation/atmosphere continuum at a temporal resolution that is in good agreement with the dynamic timescale of the atmospheric and surface processes. This study builds on previous works conducted by the authors and aims at extending our understanding of this model structure and further establishing its coherence. Herein we present the results from a thorough sensitivity analysis (SA) performed on SimSphere using a cutting edge and robust Global Sensitivity Analysis (GSA) approach, based on the use of the Gaussian Emulation Machine for Sensitivity Analysis (GEM-SA) tool. In particular, the sensitivity of selected key variables characterising land surface interactions simulated by SimSphere were evaluated at different times of model output. All model inputs were assumed to be normally distributed with their probability distribution functions (PDFs) defined using mean and variance taken from the entire theoretical range that these inputs can take in SimSphere. The sensitivity of the following SimSphere outputs was evaluated: Daily Average Net Radiation, Daily Average Latent Heat flux, Daily Average Sensible Heat flux, Daily Average Air Temperature , Daily Average Radiometric Temperature, Daily Average Surface Moisture Availability, Daily Average Evaporative Fraction and Daily Average Non-Evaporative Fraction. Our results showed largely comparable trends in terms of identifying the most sensitive model inputs in respect to the model outputs examined. In addition, a high percentage of first order interactions between the model inputs were reported, suggesting strong
DEFF Research Database (Denmark)
Faramarzi, Leila; Kontogeorgis, Georgios; Thomsen, Kaj
2009-01-01
and they cover a very wide range of conditions. Vapor-liquid equilibrium (VLE) data for the aqueous alkanolamine systems containing CO2 in the pressure range of 3-13,000 kPa and temperatures of 25-200 C are used. The model is also regressed with the VLE and freezing point depression data of the binary aqueous...... alkanolamine systems (MEA-water and MDEA-water). The two just mentioned types of data cover the full concentration range of alkanolamines from extremely dilute to almost pure. The experimental freezing point depression data down to the temperature of -20 degrees C are used. Experimental excess enthalpy (H...
A Bioinspired Neural Model Based Extended Kalman Filter for Robot SLAM
Directory of Open Access Journals (Sweden)
Jianjun Ni
2014-01-01
Full Text Available Robot simultaneous localization and mapping (SLAM problem is a very important and challenging issue in the robotic field. The main tasks of SLAM include how to reduce the localization error and the estimated error of the landmarks and improve the robustness and accuracy of the algorithms. The extended Kalman filter (EKF based method is one of the most popular methods for SLAM. However, the accuracy of the EKF based SLAM algorithm will be reduced when the noise model is inaccurate. To solve this problem, a novel bioinspired neural model based SLAM approach is proposed in this paper. In the proposed approach, an adaptive EKF based SLAM structure is proposed, and a bioinspired neural model is used to adjust the weights of system noise and observation noise adaptively, which can guarantee the stability of the filter and the accuracy of the SLAM algorithm. The proposed approach can deal with the SLAM problem in various situations, for example, the noise is in abnormal conditions. Finally, some simulation experiments are carried out to validate and demonstrate the efficiency of the proposed approach.
Directory of Open Access Journals (Sweden)
Xi Wu
2008-01-01
Full Text Available A mathematical model of a cracked rotor and an asymmetric rotor with two disks representing a turbine and a generator is utilized to study the vibrations due to imbalance and side load. Nonlinearities typically related with a “breathing” crack are included using a Mayes steering function. Numerical simulations demonstrate how the variations of rotor parameters affect the vibration response and the effect of coupling between torsional and lateral modes. Bode, spectrum, and orbit plots are used to show the differences between the vibration signatures associated with cracked shafts versus asymmetric shafts. Results show how nonlinear lateral-torsional coupling shifts the resonance peaks in the torsional vibration response for cracked shafts and asymmetric rotors. The resonance peaks shift depending on the ratio of the lateral-to-torsional natural frequencies with the peak responses occurring at noninteger values of the lateral natural frequency. When the general nonlinear models used in this study are constrained to reduce to linear torsional vibration, the peak responses occur at commonly reported integer ratios. Full spectrum analyses of the X and Y vibrations reveal distinct vibration characteristics of both cracked and asymmetric rotors including reverse vibration components. Critical speeds and vibration orders predicted using the models presented herein include and extend diagnostic indicators commonly reported.
Hilpert, Markus; Rasmuson, Anna; Johnson, William
2017-04-01
Transport of colloids in saturated porous media is significantly influenced by colloidal interactions with grain surfaces. Near-surface fluid domain colloids experience relatively low fluid drag and relatively strong colloidal forces that slow their down-gradient translation relative to colloids in bulk fluid. Near surface fluid domain colloids may re-enter into the bulk fluid via diffusion (nanoparticles) or expulsion at rear flow stagnation zones, they may immobilize (attach) via strong primary minimum interactions, or they may move along a grain-to-grain contact to the near surface fluid domain of an adjacent grain. We introduce a simple model that accounts for all possible permutations of mass transfer within a dual pore and grain network. The primary phenomena thereby represented in the model are mass transfer of colloids between the bulk and near-surface fluid domains and immobilization onto grain surfaces. Colloid movement is described by a sequence of trials in a series of unit cells, and the binomial distribution is used to calculate the probabilities of each possible sequence. Pore-scale simulations provide mechanistically-determined likelihoods and timescales associated with the above pore-scale colloid mass transfer processes, whereas the network-scale model employs pore and grain topology to determine probabilities of transfer from up-gradient bulk and near-surface fluid domains to down-gradient bulk and near-surface fluid domains. Inter-grain transport of colloids in the near surface fluid domain can cause extended tailing.
Error model of geomagnetic-field measurement and extended Kalman-filter based compensation method.
Ge, Zhilei; Liu, Suyun; Li, Guopeng; Huang, Yan; Wang, Yanni
2017-01-01
The real-time accurate measurement of the geomagnetic-field is the foundation to achieving high-precision geomagnetic navigation. The existing geomagnetic-field measurement models are essentially simplified models that cannot accurately describe the sources of measurement error. This paper, on the basis of systematically analyzing the source of geomagnetic-field measurement error, built a complete measurement model, into which the previously unconsidered geomagnetic daily variation field was introduced. This paper proposed an extended Kalman-filter based compensation method, which allows a large amount of measurement data to be used in estimating parameters to obtain the optimal solution in the sense of statistics. The experiment results showed that the compensated strength of the geomagnetic field remained close to the real value and the measurement error was basically controlled within 5nT. In addition, this compensation method has strong applicability due to its easy data collection and ability to remove the dependence on a high-precision measurement instrument.
Application of the Extended Health Control Belief Model to Predict Hepatitis A and B Vaccinations.
Reynolds, Grace L; Nguyen, Hannah H; Singh-Carlson, Savitri; Fisher, Dennis G; Odell, Anne; Xandre, Pamela
2016-09-01
Adult vaccination compliance rates vary according to sample and type of vaccine administered (influenza, pneumococcal). This study looked at vaccination of a community sample of low-income, minority adults. Nurses offered free vaccination for hepatitis A and B in the form of the combined Twinrix vaccine to adults on a walk-in basis. In addition to dosing information, participants completed the Risk Behavior Assessment, the Coping Strategies Indicator and the Cardiovascular Risk Assessment. Skaff's extended Health Belief Model was used as the theoretical framework. Count regression was used to model receipt of one, two, or three doses. The majority of participants were male with a mean age of 40 years. The distribution of doses was: 173 individuals (27.6%) received one dose only, 261 (41.7%) received two doses, and 191 (30.5%) received three doses of vaccine. The multivariate count regression model including being male, having previously been told by a health care provider that one has syphilis, having severe negative emotions, and perceived social support were associated with participants' receiving fewer doses of hepatitis vaccine. A greater problem-solving score was associated with a higher number of vaccine doses received. Despite free vaccinations offered in an easily accessible community setting, the majority of participants failed to complete the hepatitis vaccine series. More effort is needed to get adult men to participate in hepatitis vaccination clinics. Additional research is necessary to understand barriers other than cost to adults receiving vaccination. © 2016 Wiley Periodicals, Inc.
Exact solutions to a spatially extended model of kinase-receptor interaction
Szopa, Piotr; Lipniacki, Tomasz; Kazmierczak, Bogdan
2011-10-01
B and Mast cells are activated by the aggregation of the immune receptors. Motivated by this phenomena we consider a simple spatially extended model of mutual interaction of kinases and membrane receptors. It is assumed that kinase activates membrane receptors and in turn the kinase molecules bound to the active receptors are activated by transphosphorylation. Such a type of interaction implies positive feedback and may lead to bistability. In this study we apply the Steklov eigenproblem theory to analyze the linearized model and find exact solutions in the case of non-uniformly distributed membrane receptors. This approach allows us to determine the critical value of receptor dephosphorylation rate at which cell activation (by arbitrary small perturbation of the inactive state) is possible. We found that cell sensitivity grows with decreasing kinase diffusion and increasing anisotropy of the receptor distribution. Moreover, these two effects are cooperating. We showed that the cell activity can be abruptly triggered by the formation of the receptor aggregate. Since the considered activation mechanism is not based on receptor crosslinking by polyvalent antigens, the proposed model can also explain B cell activation due to receptor aggregation following binding of monovalent antigens presented on the antigen presenting cell.
Szczęsna, Agnieszka; Pruszowski, Przemysław
2016-01-01
Inertial orientation tracking is still an area of active research, especially in the context of out-door, real-time, human motion capture. Existing systems either propose loosely coupled tracking approaches where each segment is considered independently, taking the resulting drawbacks into account, or tightly coupled solutions that are limited to a fixed chain with few segments. Such solutions have no flexibility to change the skeleton structure, are dedicated to a specific set of joints, and have high computational complexity. This paper describes the proposal of a new model-based extended quaternion Kalman filter that allows for estimation of orientation based on outputs from the inertial measurements unit sensors. The filter considers interdependencies resulting from the construction of the kinematic chain so that the orientation estimation is more accurate. The proposed solution is a universal filter that does not predetermine the degree of freedom at the connections between segments of the model. To validation the motion of 3-segments single link pendulum captured by optical motion capture system is used. The next step in the research will be to use this method for inertial motion capture with a human skeleton model.
Excitation function of elastic $pp$ scattering from a unitarily extended Bialas-Bzdak model
Nemes, F.; Csanád, M.
2015-01-01
The Bialas-Bzdak model of elastic proton-proton scattering assumes a purely imaginary forward scattering amplitude, which consequently vanishes at the diffractive minima. We extended the model to arbitrarily large real parts in a way that constraints from unitarity are satisfied. The resulting model is able to describe elastic $pp$ scattering not only at the lower ISR energies but also at $\\sqrt{s}=$7~TeV in a statistically acceptable manner, both in the diffractive cone and in the region of the first diffractive minimum. The total cross-section as well as the differential cross-section of elastic proton-proton scattering is predicted for the future LHC energies of $\\sqrt{s}=$13, 14, 15~TeV and also to 28~TeV. A non-trivial, significantly non-exponential feature of the differential cross-section of elastic proton-proton scattering is analyzed and the excitation function of the non-exponential behavior is predicted. The excitation function of the shadow profiles is discussed and related to saturation at small ...
Pairing symmetries of a hole-doped extended two-orbital model for the pnictides
Energy Technology Data Exchange (ETDEWEB)
Nicholson, Andrew D [ORNL; Ge, Weihao [University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL); Riera, J. A. [Universidad Nacional de Rosario; Daghofer, Maria [ORNL; Moreo, Adriana [ORNL; Dagotto, Elbio R [ORNL
2012-01-01
The hole-doped ground state of a recently introduced extended t-U-J two-orbital Hubbard model for the Fe-based superconductors is studied via exact diagonalization methods on small clusters. Similarly as in the previously studied case of electron doping [A. Nicholson et al., Phys. Rev. Lett. 106, 217002 (2011)], upon hole doping it is observed that there are several competing pairing symmetries, including A1g , B1g , and B2g . However, contrary to the electron-doped case, the ground state of the hole-doped state has pseudocrystal momentum k = ( , ) in the unfolded Brillouin zone. In the two Fe-atom per unit cell representation, this indicates that the ground state involves antibonding, rather than bonding, combinations of the orbitals of the two Fe atoms in the unit cell. The lowest state with k = (0,0) has only a slightly higher energy. These results indicate that this simple two-orbital model may be useful to capture some subtle aspects of the hole-doped pnictides, since calculations for the five-orbital model have unveiled a hole pocket centered at M [k = ( , )] in the unfolded Brillouin zone.
Geometric-model-free tracking of extended targets using 3D lidar measurements
Steinemann, Philipp; Klappstein, Jens; Dickmann, Juergen; von Hundelshausen, Felix; Wünsche, Hans-Joachim
2012-06-01
Tracking of extended targets in high definition, 360-degree 3D-LIDAR (Light Detection and Ranging) measurements is a challenging task and a current research topic. It is a key component in robotic applications, and is relevant to path planning and collision avoidance. This paper proposes a new method without a geometric model to simultaneously track and accumulate 3D-LIDAR measurements of an object. The method itself is based on a particle filter and uses an object-related local 3D grid for each object. No geometric object hypothesis is needed. Accumulation allows coping with occlusions. The prediction step of the particle filter is governed by a motion model consisting of a deterministic and a probabilistic part. Since this paper is focused on tracking ground vehicles, a bicycle model is used for the deterministic part. The probabilistic part depends on the current state of each particle. A function for calculating the current probability density function for state transition is developed. It is derived in detail and based on a database consisting of vehicle dynamics measurements over several hundreds of kilometers. The adaptive probability density function narrows down the gating area for measurement data association. The second part of the proposed method addresses weighting the particles with a cost function. Different 3D-griddependent cost functions are presented and evaluated. Evaluations with real 3D-LIDAR measurements show the performance of the proposed method. The results are also compared to ground truth data.
Extended QoS modelling based on multi-application environment in network on chip
Saadaoui, Abdelkader; Nasri, Salem
2015-01-01
Until now, there is no standard method of the quality of service (QoS) measurement and fewer techniques have been used to provide its definition. Therefore, researchers are looking for a projection of QoS on quantifiable space, since it is qualitative, subjective and not measurable. However, a few tentatives have studied QoS parameter estimation. Many applications in network on chip (NoC) present variable QoS parameters such as packet loss rate (PLR), end-to-end delay (EED) and throughput (Thp). However, there are a few papers that have developed different methods to modelise QoS in NoC. Their QoS presentation does not provide a multi-application parameter arbiter. Independently of the approach used, an important challenge associated with QoS provision is the development of an efficient and flexible way to monitor QoS. The originality of our approach is based on a proposition of a QoS-intellectual property module in NoC architecture to improve network performances. We implement an extended approach of QoS metrics modelling for NoC on multi-parameter and multi-application environment. The QoS metrics model is based on QoS parameters such as PLR, EED and Thp for different applications. To validate this work, a dynamic routing simulation for 4 × 4 mesh NoC behaviour under three different applications, namely transmission control protocol, variable bit rate and constant bit rate, is considered. To achieve an ideal network behaviour, load balancing on NoC with multiple concurrent applications is improved using QoS metrics measurement based on dynamic routing. The results have shown that extended QoS modelling approach is easy and cheap to implement in hardware-software quantifiable representation. Thus, implementing a quantifiable representation of QoS can be used to provide a NoC services arbiter. QoS arbiter interacts with other routers to ensure flit flow and QoS modelling to provide a QoS value.
MetaboTools: A comprehensive toolbox for analysis of genome-scale metabolic models
Directory of Open Access Journals (Sweden)
Maike Kathrin Aurich
2016-08-01
Full Text Available Metabolomic data sets provide a direct read-out of cellular phenotypes and are increasingly generated to study biological questions. Previous work, by us and others, revealed the potential of analyzing extracellular metabolomic data in the context of the metabolic model using constraint-based modeling. With the MetaboTools , we make our methods available to the broader scientific community. The MetaboTools consist of a protocol, a toolbox, and tutorials of two use cases. The protocol describes, in a step-wise manner, the workflow of data integration and computational analysis. The MetaboTools comprise the Matlab code required to complete the workflow described in the protocol. Tutorials explain the computational steps for integration of two different data sets and demonstrate a comprehensive set of methods for the computational analysis of metabolic models and stratification thereof into different phenotypes. The presented workflow supports integrative analysis of multiple omics data sets. Importantly, all analysis tools can be applied to metabolic models without performing the entire workflow. Taken together, the MetaboTools constitute a comprehensive guide to the intra-model analysis of extracellular metabolomic data from microbial, plant, or human cells. This computational modeling resource offers a broad set of computational analysis tools for a wide biomedical and non-biomedical research community.
Sankar, I. V.; Chatterjee, Ashok
2014-07-01
The two-dimensional extended Holstein-Hubbard model is investigated in the strong correlation regime to study the nature of self-trapping transition and the polaron phase diagram in the absence of superconductivity. Using a series of canonical transformations followed by zero-phonon averaging the extended Holstein-Hubbard model is converted into an effective extended Hubbard model which is subsequently transformed into an effective t- J model in the strong correlation limit. This effective t- J model is finally solved using the mean-field Hartree-Fock approximation to show that the self-trapping transition is continuous in the anti-adiabatic limit while it is discontinuous in the adiabatic limit. The phase diagrams for the localization-delocalization transition, namely the phase line and the phase surface separating the small polaron and large polaron states are also shown.
HOCOMOCO: A comprehensive collection of human transcription factor binding sites models
Kulakovskiy, Ivan V.
2012-11-21
Transcription factor (TF) binding site (TFBS) models are crucial for computational reconstruction of transcription regulatory networks. In existing repositories, a TF often has several models (also called binding profiles or motifs), obtained from different experimental data. Having a single TFBS model for a TF is more pragmatic for practical applications. We show that integration of TFBS data from various types of experiments into a single model typically results in the improved model quality probably due to partial correction of source specific technique bias. We present the Homo sapiens comprehensive model collection (HOCOMOCO, http://autosome.ru/HOCOMOCO/, http://cbrc.kaust.edu.sa/ hocomoco/) containing carefully hand-curated TFBS models constructed by integration of binding sequences obtained by both low- and high-throughput methods. To construct position weight matrices to represent these TFBS models, we used ChIPMunk software in four computational modes, including newly developed periodic positional prior mode associated with DNA helix pitch. We selected only one TFBS model per TF, unless there was a clear experimental evidence for two rather distinct TFBS models. We assigned a quality rating to each model. HOCOMOCO contains 426 systematically curated TFBS models for 401 human TFs, where 172 models are based on more than one data source. The Author(s) 2012.
HOCOMOCO: a comprehensive collection of human transcription factor binding sites models.
Kulakovskiy, Ivan V; Medvedeva, Yulia A; Schaefer, Ulf; Kasianov, Artem S; Vorontsov, Ilya E; Bajic, Vladimir B; Makeev, Vsevolod J
2013-01-01
Transcription factor (TF) binding site (TFBS) models are crucial for computational reconstruction of transcription regulatory networks. In existing repositories, a TF often has several models (also called binding profiles or motifs), obtained from different experimental data. Having a single TFBS model for a TF is more pragmatic for practical applications. We show that integration of TFBS data from various types of experiments into a single model typically results in the improved model quality probably due to partial correction of source specific technique bias. We present the Homo sapiens comprehensive model collection (HOCOMOCO, http://autosome.ru/HOCOMOCO/, http://cbrc.kaust.edu.sa/hocomoco/) containing carefully hand-curated TFBS models constructed by integration of binding sequences obtained by both low- and high-throughput methods. To construct position weight matrices to represent these TFBS models, we used ChIPMunk software in four computational modes, including newly developed periodic positional prior mode associated with DNA helix pitch. We selected only one TFBS model per TF, unless there was a clear experimental evidence for two rather distinct TFBS models. We assigned a quality rating to each model. HOCOMOCO contains 426 systematically curated TFBS models for 401 human TFs, where 172 models are based on more than one data source.
Utility of ionosphere and troposphere models for extending the range of high-accuracy GPS
Dodd, David William
This dissertation studied the use of NOAA real-time ionosphere and troposphere products in extending the range of long-baseline, high-accuracy DGPS for real-time positioning. The question being addressed by this work is; can existing real-time ionosphere and troposphere models reduce the observation uncertainties to the level where they can be used to reliably resolve integer ambiguities, in real-time, over long baselines (>30km). In-house GPS processing software (USM_OTF) was developed to ingest the models and compute epoch-to-epoch, float and fixed ambiguity position solutions. Single baseline processing, ranging from 20 to 740 kin, over several days in four separate sessions (July 2004, January 2005, August 2005 and July 2006) incorporating four regions of the U.S.A. (Michigan, California, Central and the South East), were evaluated. The first session looked at the NOAA real-time troposphere model and the second session looked at the NOAA real-time ionosphere model. The third and fourth sessions looked at the use of both the NOAA real-time ionosphere and troposphere models. Results showed that the NOAA troposphere model reduced the height bias uncertainty by up to 30 cm, under high activity conditions. They also showed that the troposphere model increased the uncertainty standard deviation under these high activity conditions. The results from the first tests of the real-time NOAA ionosphere model showed that, due to satellite coverage issues, it produced worse results than other real-time models. The NOAA model suffered from lack of satellite coverage corrections, especially in areas near the limits of the model, and at the beginning and end of a satellite's flight path. A reduction in satellite numbers lead to weaker geometry and less reliable position solutions. These tests showed that it was better to provide less accurate ionosphere estimates than to leave the satellites out of the solution. These problems were addressed by NOAA prior to the final tests
Tighe, Elizabeth L.; Wagner, Richard K.; Schatschneider, Christopher
2015-01-01
This study demonstrates the utility of applying a causal indicator modeling framework to investigate important predictors of reading comprehension in third, seventh, and tenth grade students. The results indicated that a 4-factor multiple indicator multiple indicator cause (MIMIC) model of reading comprehension provided adequate fit at each grade level. This model included latent predictor constructs of decoding, verbal reasoning, nonverbal reasoning, and working memory and accounted for a large portion of the reading comprehension variance (73% to 87%) across grade levels. Verbal reasoning contributed the most unique variance to reading comprehension at all grade levels. In addition, we fit a multiple group 4-factor MIMIC model to investigate the relative stability (or variability) of the predictor contributions to reading comprehension across development (i.e., grade levels). The results revealed that the contributions of verbal reasoning, nonverbal reasoning, and working memory to reading comprehension were stable across the three grade levels. Decoding was the only predictor that could not be constrained to be equal across grade levels. The contribution of decoding skills to reading comprehension was higher in third grade and then remained relatively stable between seventh and tenth grade. These findings illustrate the feasibility of using MIMIC models to explain individual differences in reading comprehension across the development of reading skills. PMID:25821346
Study of a 30-M Boom For Solar Sail-Craft: Model Extendibility and Control Strategy
Keel, Leehyun
2005-01-01
Space travel propelled by solar sails is motivated by the fact that the momentum exchange that occurs when photons are reflected and/or absorbed by a large solar sail generates a small but constant acceleration. This acceleration can induce a constant thrust in very large sails that is sufficient to maintain a polar observing satellite in a constant position relative to the Sun or Earth. For long distance propulsion, square sails (with side length greater than 150 meters) can reach Jupiter in two years and Pluto in less than ten years. Converting such design concepts to real-world systems will require accurate analytical models and model parameters. This requires extensive structural dynamics tests. However, the low mass and high flexibility of large and light weight structures such as solar sails makes them unsuitable for ground testing. As a result, validating analytical models is an extremely difficult problem. On the other hand, a fundamental question can be asked. That is whether an analytical model that represents a small-scale version of a solar-sail boom can be extended to much larger versions of the same boom. To answer this question, we considered a long deployable boom that will be used to support the solar sails of the sail-craft. The length of fully deployed booms of the actual solar sail-craft will exceed 100 meters. However, the test-bed we used in our study is a 30 meter retractable boom at MSFC. We first develop analytical models based on Lagrange s equations and the standard Euler-Bernoulli beam. Then the response of the models will be compared with test data of the 30 meter boom at various deployed lengths. For this stage of study, our analysis was limited to experimental data obtained at 12ft and 18ft deployment lengths. The comparison results are positive but speculative. To observe properly validate the analytic model, experiments at longer deployment lengths, up to the full 30 meter, have been requested. We expect the study to answer the
Wang, Binhao; Sorin, Wayne V.; Palermo, Samuel; Tan, Michael R. T.
2016-12-01
Directly modulated vertical-cavity surface-emitting lasers (VCSELs) are commonly used in short-reach optical interconnect applications. To enable efficient optical interconnect transceiver systems operating at data rates up to 25 Gb/s and beyond, cosimulation environments, which allow for the optimization of driver circuitry with accurate compact VCSEL models, are necessary. A comprehensive VCSEL model, which captures thermally dependent electrical and optical dynamics and provides direct current, small-, and large-signal simulation capabilities with self-consistency, is presented. The device's electrical behavior is described with an equivalent circuit, which captures both large-signal operation and electrical parasitics, while the optical response is captured with a rate-equation-based model. Bias and temperature dependencies are incorporated into both key electrical and optical model parameters. Experimental verification of the model is performed at 25 Gb/s with a 990-nm VCSEL to study the impact of bias current level and substrate temperature.
Fuzzy comprehensive evaluation model of interuniversity collaborative learning based on network
Wenhui, Ma; Yu, Wang
2017-06-01
Learning evaluation is an effective method, which plays an important role in the network education evaluation system. But most of the current network learning evaluation methods still use traditional university education evaluation system, which do not take into account of web-based learning characteristics, and they are difficult to fit the rapid development of interuniversity collaborative learning based on network. Fuzzy comprehensive evaluation method is used to evaluate interuniversity collaborative learning based on the combination of fuzzy theory and analytic hierarchy process. Analytic hierarchy process is used to determine the weight of evaluation factors of each layer and to carry out the consistency check. According to the fuzzy comprehensive evaluation method, we establish interuniversity collaborative learning evaluation mathematical model. The proposed scheme provides a new thought for interuniversity collaborative learning evaluation based on network.
Gallimore, P. J.; Griffiths, P. T.; Pope, F. D.; Reid, J. P.; Kalberer, M.
2017-04-01
The chemical composition of organic aerosols profoundly influences their atmospheric properties, but a detailed understanding of heterogeneous and in-particle reactivity is lacking. We present here a combined experimental and modeling study of the ozonolysis of oleic acid particles. An online mass spectrometry (MS) method, Extractive Electrospray Ionization (EESI), is used to follow the composition of the aerosol at a molecular level in real time; relative changes in the concentrations of both reactants and products are determined during aerosol aging. The results show evidence for multiple non-first-order reactions involving stabilized Criegee intermediates, including the formation of secondary ozonides and other oligomers. Offline liquid chromatography MS is used to confirm the online MS assignment of the monomeric and dimeric products. We explain the observed EESI-MS chemical composition changes, and chemical and physical data from previous studies, using a process-based aerosol chemistry simulation, the Pretty Good Aerosol Model (PG-AM). In particular, we extend previous studies of reactant loss by demonstrating success in reproducing the time dependence of product formation and the evolving particle size. This advance requires a comprehensive chemical scheme coupled to the partitioning of semivolatile products; relevant reaction and evaporation parameters have been refined using our new measurements in combination with PG-AM.
Halder, Amit; Black, D Glenn; Davidson, P Michael; Datta, Ashim
2010-08-01
The objective of this study was to use an existing database of food products and their associated processes, link it with a list of the foodborne pathogenic microorganisms associated with those products and finally identify growth and inactivation kinetic parameters associated with those pathogens. The database was to be used as a part of the development of comprehensive software which could predict food safety and quality for any food product. The main issues in building such a predictive system included selection of predictive models, associations of different food types with pathogens (as determined from outbreak histories), and variability in data from different experiments. More than 1000 data sets from published literature were analyzed and grouped according to microorganisms and food types. Final grouping of data consisted of the 8 most prevalent pathogens for 14 different food groups, covering all of the foods (>7000) listed in the USDA Natl. Nutrient Database. Data for each group were analyzed in terms of 1st-order inactivation, 1st-order growth, and sigmoidal growth models, and their kinetic response for growth and inactivation as a function of temperature were reported. Means and 95% confidence intervals were calculated for prediction equations. The primary advantage in obtaining group-specific kinetic data is the ability to extend microbiological growth and death simulation to a large array of product and process possibilities, while still being reasonably accurate. Such simulation capability could provide vital ''what if'' scenarios for industry, Extension, and academia in food safety.
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.
Directory of Open Access Journals (Sweden)
Ilaria Barone
Full Text Available Slow, progressive rod degeneration followed by cone death leading to blindness is the pathological signature of all forms of human retinitis pigmentosa (RP. Therapeutic schemes based on intraocular delivery of neuroprotective agents prolong the lifetime of photoreceptors and have reached the stage of clinical trial. The success of these approaches depends upon optimization of chronic supply and appropriate combination of factors. Environmental enrichment (EE, a novel neuroprotective strategy based on enhanced motor, sensory and social stimulation, has already been shown to exert beneficial effects in animal models of various disorders of the CNS, including Alzheimer and Huntington disease. Here we report the results of prolonged exposure of rd10 mice, a mutant strain undergoing progressive photoreceptor degeneration mimicking human RP, to such an enriched environment from birth. By means of microscopy of retinal tissue, electrophysiological recordings, visual behaviour assessment and molecular analysis, we show that EE considerably preserves retinal morphology and physiology as well as visual perception over time in rd10 mutant mice. We find that protective effects of EE are accompanied by increased expression of retinal mRNAs for CNTF and mTOR, both factors known as instrumental to photoreceptor survival. Compared to other rescue approaches used in similar animal models, EE is highly effective, minimally invasive and results into a long-lasting retinal protection. These results open novel perspectives of research pointing to environmental strategies as useful tools to extend photoreceptor survival.
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.
The attentional drift-diffusion model extends to simple purchasing decisions.
Krajbich, Ian; Lu, Dingchao; Camerer, Colin; Rangel, Antonio
2012-01-01
How do we make simple purchasing decisions (e.g., whether or not to buy a product at a given price)? Previous work has shown that the attentional drift-diffusion model (aDDM) can provide accurate quantitative descriptions of the psychometric data for binary and trinary value-based choices, and of how the choice process is guided by visual attention. Here we extend the aDDM to the case of purchasing decisions, and test it using an eye-tracking experiment. We find that the model also provides a reasonably accurate quantitative description of the relationship between choice, reaction time, and visual fixations using parameters that are very similar to those that best fit the previous data. The only critical difference is that the choice biases induced by the fixations are about half as big in purchasing decisions as in binary choices. This suggests that a similar computational process is used to make binary choices, trinary choices, and simple purchasing decisions.
Directory of Open Access Journals (Sweden)
Siu Hing Lo
2014-02-01
Full Text Available From a corporate social responsibility perspective, there are many reasons to promote teleconference use as an alternative to business travel. The present study examines psychosocial and organizational factors relevant to teleconference use. We tested an extended Theory of Planned Behavior model of teleconference use among office workers of four organizations. Results indicate that intention was the strongest direct predictor of teleconference use. Habit and perceived norm, in turn, were the strongest predictors of intention to use teleconference. In contrast, attitude was only weakly predictive and perceived control not predictive at all of intention to use teleconference. We also examined how this model was influenced by the organizational context by comparing organizations from two different regions, and organizations from the private vs. the public sector. Most teleconference-related beliefs differed between regions and organizational sectors. The relevance of specific attitudinal and normative beliefs to the overall attitude and perceived norm also differed between organizational sectors. Implications for practice and future research are discussed.
Extending Validated Human Performance Models to Explore NextGen Concepts
Gore, Brian Francis; Hooey, Becky Lee; Mahlstedt, Eric; Foyle, David C.
2012-01-01
To meet the expected increases in air traffic demands, NASA and FAA are researching and developing Next Generation Air Transportation System (NextGen) concepts. NextGen will require substantial increases in the data available to pilots on the flight deck (e.g., weather,wake, traffic trajectory predictions, etc.) to support more precise and closely coordinated operations (e.g., self-separation, RNAV/RNP, and closely spaced parallel operations, CSPOs). These NextGen procedures and operations, along with the pilot's roles and responsibilities, must be designed with consideration of the pilot's capabilities and limitations. Failure to do so will leave the pilots, and thus the entire aviation system, vulnerable to error. A validated Man-machine Integration and design Analysis System (MIDAS) v5 model was extended to evaluate anticipated changes to flight deck and controller roles and responsibilities in NextGen approach and Land operations. Compared to conditions when the controllers are responsible for separation on decent to land phase of flight, the output from these model predictions suggest that the flight deck response time to detect the lead aircraft blunder will decrease, pilot scans to the navigation display will increase, and workload will increase.
Low energy gamma ray excess confronting a singlet scalar extended inert doublet dark matter model
Directory of Open Access Journals (Sweden)
Amit Dutta Banik
2015-04-01
Full Text Available Recent study of gamma rays originating from the region of galactic centre has confirmed an anomalous γ-ray excess within the energy range 1–3 GeV. This can be explained as the consequence of pair annihilation of a 31–40 GeV dark matter into bb¯ with thermal annihilation cross-section σv∼1.4–2.0×10−26 cm3/s. In this work we revisit the Inert Doublet Model (IDM in order to explain this gamma ray excess. Taking the lightest inert particle (LIP as a stable DM candidate we show that a 31–40 GeV dark matter derived from IDM will fail to satisfy experimental limits on dark matter direct detection cross-section obtained from ongoing direct detection experiments and is also inconsistent with LHC findings. We show that a singlet extended inert doublet model can easily explain the reported γ-ray excess which is as well in agreement with Higgs search results at LHC and other observed results like DM relic density and direct detection constraints.
Continuous data assimilation for the three-dimensional Brinkman–Forchheimer-extended Darcy model
Markowich, Peter A.
2016-03-09
In this paper we introduce and analyze an algorithm for continuous data assimilation for a three-dimensional Brinkman-Forchheimer-extended Darcy (3D BFeD) model of porous media. This model is believed to be accurate when the flow velocity is too large for Darcy\\'s law to be valid, and additionally the porosity is not too small. The algorithm is inspired by ideas developed for designing finite-parameters feedback control for dissipative systems. It aims to obtain improved estimates of the state of the physical system by incorporating deterministic or noisy measurements and observations. Specifically, the algorithm involves a feedback control that nudges the large scales of the approximate solution toward those of the reference solution associated with the spatial measurements. In the first part of the paper, we present a few results of existence and uniqueness of weak and strong solutions of the 3D BFeD system. The second part is devoted to the convergence analysis of the data assimilation algorithm. © 2016 IOP Publishing Ltd & London Mathematical Society.
Development of Extended Period Pressure-Dependent Demand Water Distribution Models
Energy Technology Data Exchange (ETDEWEB)
Judi, David R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mcpherson, Timothy N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2015-03-20
Los Alamos National Laboratory (LANL) has used modeling and simulation of water distribution systems for N-1 contingency analyses to assess criticality of water system assets. Critical components considered in these analyses include pumps, tanks, and supply sources, in addition to critical pipes or aqueducts. A contingency represents the complete removal of the asset from system operation. For each contingency, an extended period simulation (EPS) is run using EPANET. An EPS simulates water system behavior over a time period, typically at least 24 hours. It assesses the ability of a system to respond and recover from asset disruption through distributed storage in tanks throughout the system. Contingencies of concern are identified as those in which some portion of the water system has unmet delivery requirements. A delivery requirement is defined as an aggregation of water demands within a service area, similar to an electric power demand. The metric used to identify areas of unmet delivery requirement in these studies is a pressure threshold of 15 pounds per square inch (psi). This pressure threshold is used because it is below the required pressure for fire protection. Any location in the model with pressure that drops below this threshold at any time during an EPS is considered to have unmet service requirements and is used to determine cascading consequences. The outage area for a contingency is the aggregation of all service areas with a pressure below the threshold at any time during the EPS.
Liao, Yi; Ma, Xiao-Dong
2017-07-01
We revisit the effective field theory of the standard model that is extended with sterile neutrinos, N . We examine the basis of complete and independent effective operators involving N up to mass dimension seven (dim-7). By employing equations of motion, integration by parts, and Fierz and group identities, we construct relations among operators that were considered independent in the previous literature, and we find 7 redundant operators at dim-6, as well as 16 redundant operators and two new operators at dim-7. The correct numbers of operators involving N are, without counting Hermitian conjugates, 16 (L ∩B )+1 (L ∩B )+2 (L ∩ B) at dim-6 and 47 (L ∩B )+5 (L ∩ B) at dim-7. Here L /B (L/B) stands for lepton/baryon number conservation (violation). We verify our counting by the Hilbert series approach for nf generations of the standard model fermions and sterile neutrinos. When operators involving different flavors of fermions are counted separately and their Hermitian conjugates are included, we find there are 29 (1614) and 80 (4206) operators involving sterile neutrinos at dim-6 and dim-7, respectively, for nf=1 (3).
Extending the GEM model to support knowledge extraction from textual guidelines.
Georg, Gersende; Séroussi, Brigitte; Bouaud, Jacques
2005-03-01
Clinical Practice Guidelines (CPGs) are being developed as a tool to promote best practice in medicine. However, the diffusion of paper guidelines has been shown to only have a limited impact. This is why computerization of CPGs has recently been suggested as a means to improve their dissemination as well as physicians' compliance. The Guideline Elements Model (GEM) has been proposed to facilitate the encoding of CPGs and support the automatic processing of marked-up documents. In this paper, we explore the automatic generation of a rule base from a textual guideline using GEM. In this study, we propose an extension of the GEM model that introduces additional levels of structuring centered on decision variables. This allows a more efficient representation of the decision processes, which supports the automatic generation of decision rules from textual guidelines. The 1999 Canadian recommendations for the management of hypertension have been marked-up as a GEM-encoded instance of our extended DTD. We derived a rule base using an XML parser to extract the relevant elements to instantiate the IF and THEN clauses of decision rules. The rule base automatically generated compares favourably with the manual generation of decision rules in the ASTI project. This approach is an interesting case study in the computerization of CPGs, as it illustrates processing steps that are relevant to the various aspects of CPGs life-cycle, from production to consultation and use.
Right-handed neutrino dark matter in the classically conformal U(1 ) ' extended standard model
Oda, Satsuki; Okada, Nobuchika; Takahashi, Dai-suke
2017-11-01
We consider the dark matter (DM) scenario in the context of the classically conformal U(1 ) ' extended standard model (SM), with three right-handed neutrinos (RHNs) and the U(1 ) ' Higgs field. The model is free from all of the U(1 ) ' gauge and gravitational anomalies in the presence of the three RHNs. We introduce a Z2 parity in the model, under which an odd parity is assigned to one RHN, while all of the other particles are assigned to be Z2 even, and hence the Z2-odd RHN serves as a DM candidate. In this model, the U(1 ) ' gauge symmetry is radiatively broken through the Coleman-Weinberg mechanism, by which the electroweak symmetry breaking is triggered. There are three free parameters in our model—the U(1 ) ' charge of the SM Higgs doublet (xH ), the new U(1 ) ' gauge coupling (gX ), and the U(1 ) ' gauge boson (Z') mass (mZ')—which are severely constrained in order to solve the electroweak vacuum instability problem, and satisfy the LHC Run-2 bounds from the search for the Z' boson resonance. In addition to these constraints, we investigate the RHN DM physics. Because of the nature of classical conformality, we find that a RHN DM pair mainly annihilates into the SM particles through Z' boson exchange. This is the so-called Z'-portal DM scenario. Combining the electroweak vacuum stability condition, the LHC Run-2 bounds, and the cosmological constraint from the observed DM relic density, we find that all constraints work together to narrow the allowed parameter regions and, in particular, exclude mZ'≲3.5 TeV . For the obtained allowed regions, we calculate the spin-independent cross section of the RHN DM with nucleons. We find that the resultant cross section is well below the current experimental upper bounds.
St Hilaire, Melissa A; Rüger, Melanie; Fratelli, Federico; Hull, Joseph T; Phillips, Andrew J K; Lockley, Steven W
2017-01-01
Intraindividual night-to-night sleep duration is often insufficient and variable. Here we report the effects of such chronic variable sleep deficiency on neurobehavioral performance and the ability of state-of-the-art models to predict these changes. Eight healthy males (mean age ± SD: 23.9 ± 2.4 years) studied at our inpatient intensive physiologic monitoring unit completed an 11-day protocol with a baseline 10-hour sleep opportunity and three cycles of two 3-hour time-in-bed (TIB) and one 10-hour TIB sleep opportunities. Participants received one of three polychromatic white light interventions (200 lux 4100K, 200 or 400 lux 17000K) for 3.5 hours on the morning following the second 3-hour TIB opportunity each cycle. Neurocognitive performance was assessed using the psychomotor vigilance test (PVT) administered every 1-2 hours. PVT data were compared to predictions of five group-average mathematical models that incorporate chronic sleep loss functions. While PVT performance deteriorated cumulatively following each cycle of two 3-hour sleep opportunities, and improved following each 10-hour sleep opportunity, performance declined cumulatively throughout the protocol at a more accelerated rate than predicted by state-of-the-art group-average mathematical models. Subjective sleepiness did not reflect performance. The light interventions had minimal effect. Despite apparent recovery following each extended sleep opportunity, residual performance impairment remained and deteriorated rapidly when rechallenged with subsequent sleep loss. None of the group-average models were capable of predicting both the build-up in impairment and recovery profile of performance observed at the group or individual level, raising concerns regarding their use in real-world settings to predict performance and improve safety.
A Generic Bilevel Formalism for Unifying and Extending Model Reduction Methods
National Research Council Canada - National Science Library
Flippen, L
2000-01-01
An abstract, algebraic bilevel version of conventional multigrid methods has been developed that formally unifies and extends the reduced basis, substructuring, smoothing/homogenization, and frequency...
Prediction of L70 lumen maintenance and chromaticity for LEDs using extended Kalman filter models
Energy Technology Data Exchange (ETDEWEB)
Lall, Pradeep; Wei, Junchao; Davis, Lynn
2013-09-30
Solid-state lighting (SSL) luminaires containing light emitting diodes (LEDs) have the potential of seeing excessive temperatures when being transported across country or being stored in non-climate controlled warehouses. They are also being used in outdoor applications in desert environments that see little or no humidity but will experience extremely high temperatures during the day. This makes it important to increase our understanding of what effects high temperature exposure for a prolonged period of time will have on the usability and survivability of these devices. Traditional light sources “burn out” at end-of-life. For an incandescent bulb, the lamp life is defined by B50 life. However, the LEDs have no filament to “burn”. The LEDs continually degrade and the light output decreases eventually below useful levels causing failure. Presently, the TM-21 test standard is used to predict the L70 life of LEDs from LM-80 test data. Several failure mechanisms may be active in a LED at a single time causing lumen depreciation. The underlying TM-21 Model may not capture the failure physics in presence of multiple failure mechanisms. Correlation of lumen maintenance with underlying physics of degradation at system-level is needed. In this paper, Kalman Filter (KF) and Extended Kalman Filters (EKF) have been used to develop a 70-percent Lumen Maintenance Life Prediction Model for LEDs used in SSL luminaires. Ten-thousand hour LM-80 test data for various LEDs have been used for model development. System state at each future time has been computed based on the state space at preceding time step, system dynamics matrix, control vector, control matrix, measurement matrix, measured vector, process noise and measurement noise. The future state of the lumen depreciation has been estimated based on a second order Kalman Filter model and a Bayesian Framework. The measured state variable has been related to the underlying damage using physics-based models. Life
Extending the radial diffusion model of Falthammar to non-dipole background field
Energy Technology Data Exchange (ETDEWEB)
Cunningham, Gregory Scott [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2015-05-26
A model for radial diffusion caused by electromagnetic disturbances was published by Falthammar (1965) using a two-parameter model of the disturbance perturbing a background dipole magnetic field. Schulz and Lanzerotti (1974) extended this model by recognizing the two parameter perturbation as the leading (non--dipole) terms of the Mead Williams magnetic field model. They emphasized that the magnetic perturbation in such a model induces an electric ield that can be calculated from the motion of field lines on which the particles are ‘frozen’. Roederer and Zhang (2014) describe how the field lines on which the particles are frozen can be calculated by tracing the unperturbed field lines from the minimum-B location to the ionospheric footpoint, and then tracing the perturbed field (which shares the same ionospheric footpoint due to the frozen -in condition) from the ionospheric footpoint back to a perturbed minimum B location. The instantaneous change n Roederer L*, dL*/dt, can then be computed as the product (dL*/dphi)*(dphi/dt). dL*/Dphi is linearly dependent on the perturbation parameters (to first order) and is obtained by computing the drift across L*-labeled perturbed field lines, while dphi/dt is related to the bounce-averaged gradient-curvature drift velocity. The advantage of assuming a dipole background magnetic field, as in these previous studies, is that the instantaneous dL*/dt can be computed analytically (with some approximations), as can the DLL that results from integrating dL*/dt over time and computing the expected value of (dL*)^2. The approach can also be applied to complex background magnetic field models like T89 or TS04, on top of which the small perturbations are added, but an analytical solution is not possible and so a numerical solution must be implemented. In this talk, I discuss our progress in implementing a numerical solution to the calculation of DL*L* using arbitrary background field models with simple electromagnetic
So, Jiyeon
2013-01-01
For two decades, the extended parallel process model (EPPM; Witte, 1992 ) has been one of the most widely used theoretical frameworks in health risk communication. The model has gained much popularity because it recognizes that, ironically, preceding fear appeal models do not incorporate the concept of fear as a legitimate and central part of them. As a remedy to this situation, the EPPM aims at "putting the fear back into fear appeals" ( Witte, 1992 , p. 330). Despite this attempt, however, this article argues that the EPPM still does not fully capture the essence of fear as an emotion. Specifically, drawing upon Lazarus's (1991 ) cognitive appraisal theory of emotion and the concept of dispositional coping style ( Miller, 1995 ), this article seeks to further extend the EPPM. The revised EPPM incorporates a more comprehensive perspective on risk perceptions as a construct involving both cognitive and affective aspects (i.e., fear and anxiety) and integrates the concept of monitoring and blunting coping style as a moderator of further information seeking regarding a given risk topic.
Joe H. Scott; Robert E. Burgan
2005-01-01
This report describes a new set of standard fire behavior fuel models for use with Rothermel's surface fire spread model and the relationship of the new set to the original set of 13 fire behavior fuel models. To assist with transition to using the new fuel models, a fuel model selection guide, fuel model crosswalk, and set of fuel model photos are provided.
Kwiatkowska-White, Bozena; Kirby, John R.; Lee, Elizabeth A.
2016-01-01
This longitudinal study of 78 Canadian English-speaking students examined the applicability of the stability, cumulative, and compensatory models in reading comprehension development. Archival government-mandated assessments of reading comprehension at Grades 3, 6, and 10, and the Canadian Test of Basic Skills measure of reading comprehension…
Cheng, Rongjun; Ge, Hongxia; Wang, Jufeng
2017-08-01
Due to the maximum velocity and safe headway distance of the different vehicles are not exactly the same, an extended macro model of traffic flow with the consideration of multiple optimal velocity functions with probabilities is proposed in this paper. By means of linear stability theory, the new model's linear stability condition considering multiple probabilities optimal velocity is obtained. The KdV-Burgers equation is derived to describe the propagating behavior of traffic density wave near the neutral stability line through nonlinear analysis. The numerical simulations of influences of multiple maximum velocities and multiple safety distances on model's stability and traffic capacity are carried out. The cases of two different kinds of maximum speeds with same safe headway distance, two different types of safe headway distances with same maximum speed and two different max velocities and two different time-gaps are all explored by numerical simulations. First cases demonstrate that when the proportion of vehicles with a larger vmax increase, the traffic tends to unstable, which also means that jerk and brakes is not conducive to traffic stability and easier to result in stop and go phenomenon. Second cases show that when the proportion of vehicles with greater safety spacing increases, the traffic tends to be unstable, which also means that too cautious assumptions or weak driving skill is not conducive to traffic stability. Last cases indicate that increase of maximum speed is not conducive to traffic stability, while reduction of the safe headway distance is conducive to traffic stability. Numerical simulation manifests that the mixed driving and traffic diversion does not have effect on the traffic capacity when traffic density is low or heavy. Numerical results also show that mixed driving should be chosen to increase the traffic capacity when the traffic density is lower, while the traffic diversion should be chosen to increase the traffic capacity when
Greater deciduous shrub abundance extends tundra peak season and increases modeled net CO2 uptake.
Sweet, Shannan K; Griffin, Kevin L; Steltzer, Heidi; Gough, Laura; Boelman, Natalie T
2015-06-01
Satellite studies of the terrestrial Arctic report increased summer greening and longer overall growing and peak seasons since the 1980s, which increases productivity and the period of carbon uptake. These trends are attributed to increasing air temperatures and reduced snow cover duration in spring and fall. Concurrently, deciduous shrubs are becoming increasingly abundant in tundra landscapes, which may also impact canopy phenology and productivity. Our aim was to determine the influence of greater deciduous shrub abundance on tundra canopy phenology and subsequent impacts on net ecosystem carbon exchange (NEE) during the growing and peak seasons in the arctic foothills region of Alaska. We compared deciduous shrub-dominated and evergreen/graminoid-dominated community-level canopy phenology throughout the growing season using the normalized difference vegetation index (NDVI). We used a tundra plant-community-specific leaf area index (LAI) model to estimate LAI throughout the green season and a tundra-specific NEE model to estimate the impact of greater deciduous shrub abundance and associated shifts in both leaf area and canopy phenology on tundra carbon flux. We found that deciduous shrub canopies reached the onset of peak greenness 13 days earlier and the onset of senescence 3 days earlier compared to evergreen/graminoid canopies, resulting in a 10-day extension of the peak season. The combined effect of the longer peak season and greater leaf area of deciduous shrub canopies almost tripled the modeled net carbon uptake of deciduous shrub communities compared to evergreen/graminoid communities, while the longer peak season alone resulted in 84% greater carbon uptake in deciduous shrub communities. These results suggest that greater deciduous shrub abundance increases carbon uptake not only due to greater leaf area, but also due to an extension of the period of peak greenness, which extends the period of maximum carbon uptake. © 2015 John Wiley & Sons Ltd.
Jambunathan, V.; Murthy, V. R.
1993-01-01
A generic mathematical model that is capable of accurately modeling the multiple load path bearingless rotor blade is developed. A comprehensive, finite element based solution for the natural vibration of the rotor blade is developed. An iterative scheme based on harmonic balance is used to evaluate the nonlinear response of the rotor to control inputs and a Newton-Raphson procedure is employed to evaluate the trim of rotorcraft. Linearized perturbation model of the nonlinear system are presented. The model is validated by comparing with existing whirl tower, wind tunnel and flight test results of BMR/BO-105 helicopter. Frequencies of two bearingless rotor blades compare well with results from experiments. Nonlinear response and trim results are presented for the bearingless BMR/BO-105 rotor. Aeroelastic stability in forward flight, evaluated using floquet theory agrees with test data in general.
Directory of Open Access Journals (Sweden)
Parneet Paul
2015-01-01
Full Text Available Membrane bioreactors (MBRs are now main stream wastewater treatment technologies. In recent times, novel pressure driven rotating membrane disc modules have been specially developed that induce high shear on the membrane surface, thereby reducing fouling. Previous research has produced dead-end filtration fouling model which combines all three classical mechanisms that was later used by another researcher as a starting point for a greatly refined model of a cross flow side-stream MBR that incorporated both hydrodynamics and soluble microbial products’ (SMP effects. In this study, a comprehensive fouling model was created based on this earlier work that incorporated all three classical fouling mechanisms for a rotating MBR system. It was tested and validated for best fit using appropriate data sets. The initial model fit appeared good for all simulations, although it still needs to be calibrated using further appropriate data sets.
Training Inference Making Skills Using a Situation Model Approach Improves Reading Comprehension.
Bos, Lisanne T; De Koning, Bjorn B; Wassenburg, Stephanie I; van der Schoot, Menno
2016-01-01
This study aimed to enhance third and fourth graders' text comprehension at the situation model level. Therefore, we tested a reading strategy training developed to target inference making skills, which are widely considered to be pivotal to situation model construction. The training was grounded in contemporary literature on situation model-based inference making and addressed the source (text-based versus knowledge-based), type (necessary versus unnecessary for (re-)establishing coherence), and depth of an inference (making single lexical inferences versus combining multiple lexical inferences), as well as the type of searching strategy (forward versus backward). Results indicated that, compared to a control group (n = 51), children who followed the experimental training (n = 67) improved their inference making skills supportive to situation model construction. Importantly, our training also resulted in increased levels of general reading comprehension and motivation. In sum, this study showed that a 'level of text representation'-approach can provide a useful framework to teach inference making skills to third and fourth graders.
Training Inference Making Skills Using a Situation Model Approach Improves Reading Comprehension
Directory of Open Access Journals (Sweden)
Lisanne eBos
2016-02-01
Full Text Available This study aimed to enhance third and fourth graders’ text comprehension at the situation model level. Therefore, we tested a reading strategy training developed to target inference making skills, which are widely considered to be pivotal to situation model construction. The training was grounded in contemporary literature on situation model-based inference making and addressed the source (text-based versus knowledge-based, type (necessary versus unnecessary for (re-establishing coherence, and depth of an inference (making single lexical inferences versus combining multiple lexical inferences, as well as the type of searching strategy (forward versus backward. Results indicated that, compared to a control group (n = 51, children who followed the experimental training (n = 67 improved their inference making skills supportive to situation model construction. Importantly, our training also resulted in increased levels of general reading comprehension and motivation. In sum, this study showed that a ‘level of text representation’-approach can provide a useful framework to teach inference making skills to third and fourth graders.
Training Inference Making Skills Using a Situation Model Approach Improves Reading Comprehension
Bos, Lisanne T.; De Koning, Bjorn B.; Wassenburg, Stephanie I.; van der Schoot, Menno
2016-01-01
This study aimed to enhance third and fourth graders’ text comprehension at the situation model level. Therefore, we tested a reading strategy training developed to target inference making skills, which are widely considered to be pivotal to situation model construction. The training was grounded in contemporary literature on situation model-based inference making and addressed the source (text-based versus knowledge-based), type (necessary versus unnecessary for (re-)establishing coherence), and depth of an inference (making single lexical inferences versus combining multiple lexical inferences), as well as the type of searching strategy (forward versus backward). Results indicated that, compared to a control group (n = 51), children who followed the experimental training (n = 67) improved their inference making skills supportive to situation model construction. Importantly, our training also resulted in increased levels of general reading comprehension and motivation. In sum, this study showed that a ‘level of text representation’-approach can provide a useful framework to teach inference making skills to third and fourth graders. PMID:26913014
Wu, Xiaoyu; Gao, Yuan
2011-01-01
This paper applies the extended technology acceptance model (exTAM) in information systems research to the use of clickers in student learning. The technology acceptance model (TAM) posits that perceived ease of use and perceived usefulness of technology influence users' attitudes toward using and intention to use technology. Research subsequent…
Janicak, Philip G; O'Reardon, John P; Sampson, Shirlene M; Husain, Mustafa M; Lisanby, Sarah H; Rado, Jeffrey T; Heart, Karen L; Demitrack, Mark A
2008-02-01
Transcranial magnetic stimulation (TMS) has demonstrated efficacy in the treatment of major depressive disorder; however, prior studies have provided only partial safety information. We examined the acute efficacy of TMS in a randomized sham-controlled trial, under open-label conditions, and its durability of benefit. Aggregate safety data were obtained from a comprehensive clinical development program examining the use of TMS in the treatment of major depressive disorder. There were 3 separate clinical protocols, including 325 patients from 23 clinical sites in the United States, Australia, and Canada. Active enrollment occurred between January 2004 and August 2005. Adverse events were assessed at each study visit by review of spontaneous reports with separate reporting of serious adverse events. Safety assessments were also completed for cognitive function and auditory threshold. Assessment of disease-specific risk included the potential for worsening of depressive symptoms. Finally, the time course and accommodation to the most commonly appearing adverse events were considered. TMS was administered in over 10,000 cumulative treatment sessions in the study program. There were no deaths or seizures. Most adverse events were mild to moderate in intensity. Transient headaches and scalp discomfort were the most common adverse events. Auditory threshold and cognitive function did not change. There was a low discontinuation rate (4.5%) due to adverse events during acute treatment. TMS was associated with a low incidence of adverse events that were mild to moderate in intensity and demonstrated a largely predictable time course of resolution. TMS may offer clinicians a novel, well-tolerated alternative for the treatment of major depressive disorder that can be safely administered in an outpatient setting. clinicaltrials.gov Identifier: NCT00104611.
Inoue, Kentaro; Maeda, Kazuhiro; Miyabe, Takaaki; Matsuoka, Yu; Kurata, Hiroyuki
2014-09-01
Mathematical modeling has become a standard technique to understand the dynamics of complex biochemical systems. To promote the modeling, we had developed the CADLIVE dynamic simulator that automatically converted a biochemical map into its associated mathematical model, simulated its dynamic behaviors and analyzed its robustness. To enhance the feasibility by CADLIVE and extend its functions, we propose the CADLIVE toolbox available for MATLAB, which implements not only the existing functions of the CADLIVE dynamic simulator, but also the latest tools including global parameter search methods with robustness analysis. The seamless, bottom-up processes consisting of biochemical network construction, automatic construction of its dynamic model, simulation, optimization, and S-system analysis greatly facilitate dynamic modeling, contributing to the research of systems biology and synthetic biology. This application can be freely downloaded from http://www.cadlive.jp/CADLIVE_MATLAB/ together with an instruction.
Dasgupta, Anandaroop; Sansgiry, Sujit S; Sherer, Jeff T; Wallace, David; Sikri, Samir
2009-01-01
To evaluate pharmacists' behavioral intention to use personal digital assistants (PDAs) in their profession, by means of the Extended Technology Acceptance Model (ETAM). Prospective cross-sectional study. Hospital and community pharmacies in Houston, TX, in 2004. Convenience sample of 295 practicing pharmacists. A prevalidated survey containing 30 items, evaluated on a 5-point Likert scale (1, strongly disagree, to 5, strongly agree), which measured the ETAM variables. Predictors of intention to use PDA for pharmacists owning the device. Among the surveyed population, 49% of pharmacists owned PDAs. Overall, the ETAM constructs showed fairly good reliability. Stepwise regression analysis showed that the ETAM explained 69% of the variance in intention to use PDAs for pharmacists owning the device. Result demonstrability (beta = 0.53), subjective norm (beta = 0.25), and voluntariness (beta = -0.10) were significant (P ETAM proved useful in predicting pharmacists' behavior in using PDAs. With improvements in technology, PDAs be an effective tool for pharmacists in providing better patient care.
Detection of Emerging Faults on Industrial Gas Turbines Using Extended Gaussian Mixture Models
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Yu Zhang
2017-01-01
Full Text Available This paper extends traditional Gaussian mixture model (GMM techniques to provide recognition of operational states and detection of emerging faults for industrial systems. A variational Bayesian method allows a GMM to cluster with its mixture components to facilitate the extraction of steady-state operational behaviour; this is recognised as being a primary factor in reducing the susceptibility of alternative prognostic/diagnostic techniques, which would initiate false-alarms resulting from control set-point and load changes. Furthermore, a GMM with an outlier component is discussed and applied for direct novelty/fault detection. An advantage of the variational Bayesian method over traditional predefined thresholds is the extraction of steady-state data during both full- and part-load cases, and a primary advantage of the GMM with an outlier component is its applicability for novelty detection when there is a lack of prior knowledge of fault patterns. Results obtained from the real-time measurements on the operational industrial gas turbines have shown that the proposed technique provides integrated preprocessing, benchmarking, and novelty/fault detection methodology.
Numerical modeling approach of sinkhole propagation using the eXtended FEM code 'roxol'
Schneider-Löbens, Christiane; Wuttke, Manfred W.; Backers, Tobias; Krawczyk, Charlotte
2015-04-01
Subrosion and underground cavities lead to instability of the earth's surface. To minimize sinkhole hazard, it is necessary to have a better understanding of the processes and collapse mechanisms. Recent cases of subrosion in Germany that result in collapse structures (sinkholes) are used as a basis for this study. The aim is to simulate the collapse mechanism in order to specify the conditions in which sinkholes form. Using the XFEM code `roxol` (geomecon GmbH), it is possible to localize zones, in which rock failure occurs. Initiation of fracture propagation and interaction within these zones can be simulated. As a first approximation, we use a 2D model with simplified excavation and fault geometry and assume linear elastic, impermeable and non-poroelastic material behavior for the overburden layers; local stress field parameters are supplied by boundary conditions. We estimate the distribution of stress and strain in areas with critical loads to simulate failure under the influence of the stress field, material properties, as well as fault and joint geometry. Varying these parameters allows the calculation of the critical loads in which fractures propagate and failure occurs. The XFEM code `roxol` is a suitable approach to simulate the development of sinkholes. In this study, fracture propagation, as well as the interaction between existing joints are the most important parameters. Therefore, our first approach will be extended by local input parameters to develop predictions of time-dependent rock failure.
E-COCOMO: The Extended COst Constructive MOdel for Cleanroom Software Engineering
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Hitesh KUMAR SHARMA
2014-02-01
Full Text Available Mistakes create rework. Rework takes time and increases costs. The traditional software engineering methodology defines the ratio of Design:Code:Test as 40:20:40. As we can easily see that 40% time and efforts are used in testing phase in traditional approach, that means we have to perform rework again if we found some bugs in testing phase. This rework is being performed after Design and code phase. This rework will increase the cost exponentially. The cleanroom software engineering methodology controls the exponential growth in cost by removing this rework. It says that "do the work correct in first attempt and move to next phase after getting the proof of correctness". This new approach minimized the rework and reduces the cost in the exponential ratio. Due to the removal of testing phase, the COCOMO (COst COnstructive MOdel used for the traditional engineering is not directly applicable in cleanroom software engineering. The traditional cost drivers used for traditional COCOMO needs to be revised. We have proposed the Extended version of COCOMO (i.e. E-COCOMO in which we have incorporated some new cost drivers. This paper explains the proposed E-COCOMO and the detailed description of proposed new cost driver.
An Extended Finite Element Model for Fluid Flow in Fractured Porous Media
Directory of Open Access Journals (Sweden)
Fei Liu
2015-01-01
Full Text Available This paper proposes a numerical model for the fluid flow in fractured porous media with the extended finite element method. The governing equations account for the fluid flow in the porous medium and the discrete natural fractures, as well as the fluid exchange between the fracture and the porous medium surrounding the fracture. The pore fluid pressure is continuous, while its derivatives are discontinuous on both sides of these high conductivity fractures. The pressure field is enriched by the absolute signed distance and appropriate asymptotic functions to capture the discontinuities in derivatives. The most important advantage of this method is that the domain can be partitioned as nonmatching grid without considering the presence of fractures. Arbitrarily multiple, kinking, branching, and intersecting fractures can be treated with the new approach. In particular, for propagating fractures, such as hydraulic fracturing or network volume fracturing in fissured reservoirs, this method can process the complex fluid leak-off behavior without remeshing. Numerical examples are presented to demonstrate the capability of the proposed method in saturated fractured porous media.
Numerical Device Modeling, Analysis, and Optimization of Extended-SWIR HgCdTe Infrared Detectors
Schuster, J.; DeWames, R. E.; DeCuir, E. A.; Bellotti, E.; Dhar, N.; Wijewarnasuriya, P. S.
2016-09-01
Imaging in the extended short-wavelength infrared (eSWIR) spectral band (1.7-3.0 μm) for astronomy applications is an area of significant interest. However, these applications require infrared detectors with extremely low dark current (less than 0.01 electrons per pixel per second for certain applications). In these detectors, sources of dark current that may limit the overall system performance are fundamental and/or defect-related mechanisms. Non-optimized growth/device processing may present material point defects within the HgCdTe bandgap leading to Shockley-Read-Hall dominated dark current. While realizing contributions to the dark current from only fundamental mechanisms should be the goal for attaining optimal device performance, it may not be readily feasible with current technology and/or resources. In this regard, the U.S. Army Research Laboratory performed physics-based, two- and three-dimensional numerical modeling of HgCdTe photovoltaic infrared detectors designed for operation in the eSWIR spectral band. The underlying impetus for this capability and study originates with a desire to reach fundamental performance limits via intelligent device design.
Directory of Open Access Journals (Sweden)
Valery Ivanovich ELFIMOV
2014-07-01
Full Text Available In this study, the performance of the extended shallow water model (ESWM in evaluation of the flow regime of turbidity currents entering the Dez Reservoir was investigated. The continuity equations for fluid and particles and the Navier-Stokes equations govern the entire flow of turbidity currents. The shallow water equations governing the flow of the depositing phase of turbidity currents are derived from these equations. A case study was conducted on the flow regime of turbidity currents entering the Dez Reservoir in Iran from January 2002 to July 2003. Facing a serious sedimentation problem, the dead storage of the Dez Reservoir will be full in the coming 10 years, and the inflowing water in the hydropower conduit system is now becoming turbid. Based on the values of the dimensionless friction number ( and dimensionless entrainment number ( of turbidity currents, and the coefficient of determination between the observed and predicted deposit depths (R2 = 0.86 for the flow regime of negligible friction and negligible entrainment (NFNE, the flow regime of turbidity currents coming into the Dez Reservoir is considered to be NFNE. The results suggest that the ESWM is an appropriate approach for evaluation of the flow regime of turbidity currents in dam reservoirs where the characteristics of turbidity currents, such as the deposit depth, must be evaluated.
Ochoa, Maicol A.; Bruch, Anton; Nitzan, Abraham
2016-07-01
We study the energy distribution in the extended resonant level model at equilibrium. Previous investigations [Phys. Rev. B 89, 161306 (2014), 10.1103/PhysRevB.89.161306; Phys. Rev. B 93, 115318 (2016), 10.1103/PhysRevB.93.115318] have found, for a resonant electronic level interacting with a thermal free-electron wide-band bath, that the expectation value for the energy of the interacting subsystem can be correctly calculated by considering a symmetric splitting of the interaction Hamiltonian between the subsystem and the bath. However, the general implications of this approach were questioned [Phys. Rev. B 92, 235440 (2015), 10.1103/PhysRevB.92.235440]. Here, we show that, already at equilibrium, such splitting fails to describe the energy fluctuations, as measured here by the second and third central moments (namely, width and skewness) of the energy distribution. Furthermore, we find that when the wide-band approximation does not hold, no splitting of the system-bath interaction can describe the system thermodynamics. We conclude that in general no proper division subsystem of the Hamiltonian of the composite system can account for the energy distribution of the subsystem. This also implies that the thermodynamic effects due to local changes in the subsystem cannot in general be described by such splitting.
Dey, Mahua; Yu, Dou; Kanojia, Deepak; Li, Gina; Sukhanova, Madina; Spencer, Drew A; Pituch, Katatzyna C; Zhang, Lingjiao; Han, Yu; Ahmed, Atique U; Aboody, Karen S; Lesniak, Maciej S; Balyasnikova, Irina V
2016-09-13
The challenges to effective drug delivery to brain tumors are twofold: (1) there is a lack of non-invasive methods of local delivery and (2) the blood-brain barrier limits systemic delivery. Intranasal delivery of therapeutics to the brain overcomes both challenges. In mouse model of malignant glioma, we observed that a small fraction of intranasally delivered neural stem cells (NSCs) can migrate to the brain tumor site. Here, we demonstrate that hypoxic preconditioning or overexpression of CXCR4 significantly enhances the tumor-targeting ability of NSCs, but without altering their phenotype only in genetically modified NSCs. Modified NSCs deliver oncolytic virus to glioma more efficiently and extend survival of experimental animals in the context of radiotherapy. Our findings indicate that intranasal delivery of stem cell-based therapeutics could be optimized for future clinical applications, and allow for safe and repeated administration of biological therapies to brain tumors and other CNS disorders. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.
Neuron-specific antioxidant OXR1 extends survival of a mouse model of amyotrophic lateral sclerosis.
Liu, Kevin X; Edwards, Benjamin; Lee, Sheena; Finelli, Mattéa J; Davies, Ben; Davies, Kay E; Oliver, Peter L
2015-05-01
Amyotrophic lateral sclerosis is a devastating neurodegenerative disorder characterized by the progressive loss of spinal motor neurons. While the aetiological mechanisms underlying the disease remain poorly understood, oxidative stress is a central component of amyotrophic lateral sclerosis and contributes to motor neuron injury. Recently, oxidation resistance 1 (OXR1) has emerged as a critical regulator of neuronal survival in response to oxidative stress, and is upregulated in the spinal cord of patients with amyotrophic lateral sclerosis. Here, we tested the hypothesis that OXR1 is a key neuroprotective factor during amyotrophic lateral sclerosis pathogenesis by crossing a new transgenic mouse line that overexpresses OXR1 in neurons with the SOD1(G93A) mouse model of amyotrophic lateral sclerosis. Interestingly, we report that overexpression of OXR1 significantly extends survival, improves motor deficits, and delays pathology in the spinal cord and in muscles of SOD1(G93A) mice. Furthermore, we find that overexpression of OXR1 in neurons significantly delays non-cell-autonomous neuroinflammatory response, classic complement system activation, and STAT3 activation through transcriptomic analysis of spinal cords of SOD1(G93A) mice. Taken together, these data identify OXR1 as the first neuron-specific antioxidant modulator of pathogenesis and disease progression in SOD1-mediated amyotrophic lateral sclerosis, and suggest that OXR1 may serve as a novel target for future therapeutic strategies. © The Author (2015). Published by Oxford University Press on behalf of the Guarantors of Brain.
Rosa, Regis Goulart; Tonietto, Tulio Frederico; da Silva, Daiana Barbosa; Gutierres, Franciele Aparecida; Ascoli, Aline Maria; Madeira, Laura Cordeiro; Rutzen, William; Falavigna, Maicon; Robinson, Caroline Cabral; Salluh, Jorge Ibrain; Cavalcanti, Alexandre Biasi; Azevedo, Luciano Cesar; Cremonese, Rafael Viegas; Haack, Tarissa Ribeiro; Eugênio, Cláudia Severgnini; Dornelles, Aline; Bessel, Marina; Teles, José Mario Meira; Skrobik, Yoanna; Teixeira, Cassiano
2017-10-01
To evaluate the effect of an extended visitation model compared with a restricted visitation model on the occurrence of delirium among ICU patients. Prospective single-center before and after study. Thirty-one-bed medical-surgical ICU. All patients greater than or equal to 18 years old with expected length of stay greater than or equal to 24 hours consecutively admitted to the ICU from May 2015 to November 2015. Change of visitation policy from a restricted visitation model (4.5 hr/d) to an extended visitation model (12 hr/d). Two hundred eighty-six patients were enrolled (141 restricted visitation model, 145 extended visitation model). The primary outcome was the cumulative incidence of delirium, assessed bid using the confusion assessment method for the ICU. Predefined secondary outcomes included duration of delirium/coma; any ICU-acquired infection; ICU-acquired bloodstream infection, pneumonia, and urinary tract infection; all-cause ICU mortality; and length of ICU stay. The median duration of visits increased from 133 minutes (interquartile range, 97.7-162.0) in restricted visitation model to 245 minutes (interquartile range, 175.0-272.0) in extended visitation model (p delirium in extended visitation model compared with 29 (20.5%) in restricted visitation model (adjusted relative risk, 0.50; 95% CI, 0.26-0.95). In comparison with restricted visitation model patients, extended visitation model patients had shorter length of delirium/coma (1.5 d [interquartile range, 1.0-3.0] vs 3.0 d [interquartile range, 2.5-5.0]; p = 0.03) and ICU stay (3.0 d [interquartile range, 2.0-4.0] vs 4.0 d [interquartile range, 2.0-6.0]; p = 0.04). The rate of ICU-acquired infections and all-cause ICU mortality did not differ significantly between the two study groups. In this medical-surgical ICU, an extended visitation model was associated with reduced occurrence of delirium and shorter length of delirium/coma and ICU stay.
One facility's experience in reframing nonfeeding into a comprehensive palliative care model.
Vesely, Claire; Beach, Barbara
2013-01-01
In Western culture, feeding is viewed as symbolic of life, and nonfeeding at the end of life is often considered unacceptable. This sentiment is magnified for infants. Reframing nonfeeding into comprehensive care can be achieved by anticipatory guidance, which can make the experience of infant death meaningful for parents. Since 2004, the George Mark Children's House, an inpatient pediatric palliative care center, has offered this model of care and supported families with challenging clinical experiences. A case study is provided. © 2013 AWHONN, the Association of Women's Health, Obstetric and Neonatal Nurses.
Non-equilibrium modeling of the PMSE Overshoot Effect revisited: A comprehensive study
Biebricher, Alexander; Havnes, Ove
2012-06-01
Numerical investigations of the Polar Mesosphere Summer Echoes (PMSE) Overshoot Effect have to date been undertaken under the premise of plasma neutrality and current equilibrium at any time. We find it necessary to revisit the calculations without these restrictions, since electrons and ions are attached to and absorbed by mesospheric dust particles at vastly different rates under PMSE conditions. We find that differences to earlier modeling might be so significant as to warrant further investigation. Furthermore, we conduct comprehensive studies of the PMSE Overshoot Effect and put the results in the context of experimental realities.
Energy Technology Data Exchange (ETDEWEB)
Hassanein, A.
1998-08-26
Damage to plasma-facing components (PFCS) from plasma instabilities remains a major obstacle to a successful tokamak concept. The extent of the damage depends on the detailed physics of the disrupting plasma, as well as on the physics of plasma-material interactions. A comprehensive computer package called High Energy Interaction with General Heterogeneous Target Systems (HEIGHTS) has been developed and consists of several integrated computer models that follow the beginning of a plasma disruption at the scrape-off layer (SOL) through the transport of the eroded debris and splashed target materials to nearby locations as a result of the deposited energy. The package can study, for the first time, plasma-turbulent behavior in the SOL and predict the plasma parameters and conditions at the divertor plate. Full two-dimensional (2-D) comprehensive radiation magnetohydrodynamic (MHD) models are coupled with target thermodynamics and liquid hydrodynamics to evaluate the integrated response of plasma-facing materials. Factors that influence the lifetime of plasma-facing and nearby components, such as loss of vapor-cloud confinement and vapor removal due to MHD effects, damage to nearby components due to intense vapor radiation, melt splashing, and brittle destruction of target materials, are also modeled and discussed.
Pan, Xinyi; Li, Cheng; Ying, Kui; Weng, Dehe; Qin, Wen; Li, Kuncheng
2010-04-01
A model-based proton resonance frequency shift (PRFS) thermometry method was developed to significantly reduce the temperature quantification errors encountered in the conventional phase mapping method and the spatiotemporal limitations of the spectroscopic thermometry method. Spectral data acquired using multi-echo gradient echo (GRE) is fit into a two-component signal model containing temperature information and fat is used as the internal reference. The noniterative extended Prony algorithm is used for the signal fitting and frequency estimate. Monte Carlo simulations demonstrate the advantages of the method for optimal water-fat separation and temperature estimation accuracy. Phantom experiments demonstrate that the model-based method effectively reduces the interscan motion effects and frequency disturbances due to the main field drift. The thermometry result of ex vivo goose liver experiment with high intensity focused ultrasound (HIFU) heating was also presented in the paper to indicate the feasibility of the model-based method in real tissue. Copyright 2010 Elsevier Inc. All rights reserved.
Flórez, Gerardo; Casas, Alfonso; Kreis, Mette K F; Forti, Leonello; Martínez, Joaquín; Fernández, Juan; Conde, Manuel; Vázquez-Noguerol, Raúl; Blanco, Tania; Hoff, Helge A; Cooke, David J
2015-10-01
The Comprehensive Assessment of Psychopathic Personality (CAPP) is a newly developed, lexically based, conceptual model of psychopathy. The content validity of the Spanish language CAPP model was evaluated using prototypicality analysis. Prototypicality ratings were collected from 187 mental health experts and from samples of 143 health professionals and 282 community residents. Across the samples the majority of CAPP items were rated as highly prototypical of psychopathy. The Self, Dominance, and Attachment domains were evaluated as being more prototypical than the Behavioral and Cognitive domains. These findings are consistent with findings from similar studies in other languages and provide further support for the content validation of the CAPP model across languages and the lexical approach.
Major, Jason T.; Johnson, Wendy; Deary, Ian J.
2012-01-01
Three prominent theories of intelligence, the Cattell-Horn-Carroll (CHC), extended fluid-crystallized (Gf-Gc) and verbal-perceptual-image rotation (VPR) theories, provide differing descriptions of the structure of intelligence (McGrew, 2009; Horn & Blankson, 2005; Johnson & Bouchard, 2005b). To compare these theories, models representing them were…
CSIR Research Space (South Africa)
Machaka, R
2015-05-01
Full Text Available A brief background to compaction equations and their application to titanium powder is presented. The behavior and mechanisms of densification in selected titanium powders is critically analyzed by means of a comprehensive inter-model comparison...
Computational exploration of metaphor comprehension processes using a semantic space model.
Utsumi, Akira
2011-03-01
Recent metaphor research has revealed that metaphor comprehension involves both categorization and comparison processes. This finding has triggered the following central question: Which property determines the choice between these two processes for metaphor comprehension? Three competing views have been proposed to answer this question: the conventionality view (Bowdle & Gentner, 2005), aptness view (Glucksberg & Haught, 2006b), and interpretive diversity view (Utsumi, 2007); these views, respectively, argue that vehicle conventionality, metaphor aptness, and interpretive diversity determine the choice between the categorization and comparison processes. This article attempts to answer the question regarding which views are plausible by using cognitive modeling and computer simulation based on a semantic space model. In the simulation experiment, categorization and comparison processes are modeled in a semantic space constructed by latent semantic analysis. These two models receive word vectors for the constituent words of a metaphor and compute a vector for the metaphorical meaning. The resulting vectors can be evaluated according to the degree to which they mimic the human interpretation of the same metaphor; the maximum likelihood estimation determines which of the two models better explains the human interpretation. The result of the model selection is then predicted by three metaphor properties (i.e., vehicle conventionality, aptness, and interpretive diversity) to test the three views. The simulation experiment for Japanese metaphors demonstrates that both interpretive diversity and vehicle conventionality affect the choice between the two processes. On the other hand, it is found that metaphor aptness does not affect this choice. This result can be treated as computational evidence supporting the interpretive diversity and conventionality views. Copyright © 2010 Cognitive Science Society, Inc.
Comas-Herrera, Adelina; Knapp, Martin; Wittenberg, Raphael; Banerjee, Sube; Bowling, Ann; Grundy, Emily; Jagger, Carol; Farina, Nicolas; Lombard, Daniel; Lorenz, Klara; McDaid, David
2017-01-11
The MODEM project (A comprehensive approach to MODelling outcome and costs impacts of interventions for DEMentia) explores how changes in arrangements for the future treatment and care of people living with dementia, and support for family and other unpaid carers, could result in better outcomes and more efficient use of resources. MODEM starts with a systematic mapping of the literature on effective and (potentially) cost-effective interventions in dementia care. Those findings, as well as data from a cohort, will then be used to model the quality of life and cost impacts of making these evidence-based interventions more widely available in England over the period from now to 2040. Modelling will use a suite of models, combining microsimulation and macrosimulation methods, modelling the costs and outcomes of care, both for an individual over the life-course from the point of dementia diagnosis, and for individuals and England as a whole in a particular year. Project outputs will include an online Dementia Evidence Toolkit, making evidence summaries and a literature database available free to anyone, papers in academic journals and other written outputs, and a MODEM Legacy Model, which will enable local commissioners of services to apply the model to their own populations. Modelling the effects of evidence-based cost-effective interventions and making this information widely available has the potential to improve the health and quality of life both of people with dementia and their carers, while ensuring that resources are used efficiently.
Energy Technology Data Exchange (ETDEWEB)
Dzhioev, Alan [Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation)]. E-mail: dzhioev@thsun1.jinr.ru; Wambach, J. [Institut fuer Kernphysik, Technische Universitaet Darmstadt, D-64289 Darmstadt (Germany); Gesellschaft fuer Schwerionenforschung, D-64291 Darmstadt (Germany)]. E-mail: wambach@physik.tu-darmstadt.de; Vdovin, A. [Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation)]. E-mail: vdovin@thsun1.jinr.ru; Aouissat, Z. [Institut fuer Kernphysik, Technische Universitaet Darmstadt, D-64289 Darmstadt (Germany)
2005-02-21
Symmetry conserving 1/N expansion method combined with the Holstein-Primakoff mapping for bosonic systems is applied to the quantum anharmonic O(N+1) oscillator model which imitates essential features of the quantum-field linear sigma model. The Holstein-Primakoff mapping earlier extended to incorporate both single- and double-boson images is used. In the leading and next-to-leading order the existence of N-Goldstone modes and the validity of the Ward identity are proved. For matrix elements of the pion-pion interaction we show the equivalence of the results obtained via a diagrammatic technique and the extended Holstein-Primakoff mapping.
The comprehensive cohort model in a pilot trial in orthopaedic trauma
Directory of Open Access Journals (Sweden)
Parsons Nick R
2011-04-01
preference group to create a comprehensive cohort of patients has been suggested as a way of increasing the power of such trials. In our study, the comprehensive cohort model doubled the number of patients involved in the study. However, a strong preference for non-operative treatment meant that the increased number of patients did not significantly increase the ability of the trial to detect a difference between the two interventions. Trial registration ISRCTN: ISRCTN29053307
The benefits of extended plate motion history in mantle circulation models
Webb, Peter; Davies, Huw; Davies, Rhodri; Hochard, Cyril; Stampfli, Gerard
2010-05-01
Mantle Circulation Models (MCMs) are mantle convection simulations conditioned with plate motion history. Due to difficulties in reconstructing plate motions beyond ≈ 120 Ma, MCMs often only incorporate the most recent 120 Myr of plate tectonic evolution. We find that such models are strongly influenced by initial conditions. The development of a new series of tectonic reconstructions extending back to the Triassic (230 Ma) and including careful reconstruction of the oceanic parts of the plates (modified from Stampfli and Borel, 2004, Stampfli et al. 2008 and references therein) should prove to be of huge importance to MCMs. In this study we present a comparison between the traditionally used 120 Myr and the latest 230 Myr plate motion histories. We use the three-dimensional spherical mantle convection code TERRA (Bunge et al., 2003) to simulate convection at Earth like vigour. Here we apply the plate motion history as a surface velocity boundary condition to drive the internal convection of an already well-mixed system. The forward models from a chosen starting point to present day yield information on mantle temperature (as well as pressure, velocity and material properties) throughout the volume. One of the ways to validate our results is to compare these with tomographic models. Seismic tomography provides us with a snapshot of Earth's mantle at present day. Assuming that the mantle is driven largely by thermal convection, we can assume that the seismically fast regions are associated with cooler, denser material. The most significant of these can be interpreted as remnants of subducted slabs (Hafkenscheid et al 2006, van der Meer et al. 2010). We convert the temperatures predicted by the MCM to seismic velocities using the latest techniques (e.g. Cobden et al., 2008) and compare the calculated velocities to a range of seismic tomography models (both P and S wave). This way we can examine the validity of the surface velocity boundary condition and identify
UV-extended E-MILES stellar population models: young components in massive early-type galaxies
Vazdekis, A.; Koleva, M.; Ricciardelli, E.; Röck, B.; Falcón-Barroso, J.
2016-01-01
We present UV extended E MILES stellar population synthesis models covering the spectral range ?? 1680 50 000 Å at moderately high resolution. We employ the NGSL space based stellar library to compute spectra of single age single metallicity stellar populations in the wavelength range from 1680 to 3540 Å. These models represent a significant improvement in resolution and age/metallicity coverage over previous studies based on earlier space based libraries. These model spectra were joined with...
Birbarah, Patrick; Li, Zhaoer; Pauls, Alexander; Miljkovic, Nenad
2015-07-21
Superhydrophobic micro/nanostructured surfaces for dropwise condensation have recently received significant attention due to their potential to enhance heat transfer performance by shedding positively charged water droplets via coalescence-induced droplet jumping at length scales below the capillary length and allowing the use of external electric fields to enhance droplet removal and heat transfer, in what has been termed electric-field-enhanced (EFE) jumping-droplet condensation. However, achieving optimal EFE conditions for enhanced heat transfer requires capturing the details of transport processes that is currently lacking. While a comprehensive model has been developed for condensation on micro/nanostructured surfaces, it cannot be applied for EFE condensation due to the dynamic droplet-vapor-electric field interactions. In this work, we developed a comprehensive physical model for EFE condensation on superhydrophobic surfaces by incorporating individual droplet motion, electrode geometry, jumping frequency, field strength, and condensate vapor-flow dynamics. As a first step toward our model, we simulated jumping droplet motion with no external electric field and validated our theoretical droplet trajectories to experimentally obtained trajectories, showing excellent temporal and spatial agreement. We then incorporated the external electric field into our model and considered the effects of jumping droplet size, electrode size and geometry, condensation heat flux, and droplet jumping direction. Our model suggests that smaller jumping droplet sizes and condensation heat fluxes require less work input to be removed by the external fields. Furthermore, the results suggest that EFE electrodes can be optimized such that the work input is minimized depending on the condensation heat flux. To analyze overall efficiency, we defined an incremental coefficient of performance and showed that it is very high (∼10(6)) for EFE condensation. We finally proposed mechanisms
Enomoto, Masataka; Kigin, Patricia D; Bledsoe, David; Slone, Robyn; Hash, Jonathan; Smith, Charles E; Lascelles, B Duncan X
2017-01-24
Non-steroidal anti-inflammatory drugs (NSAIDs), transdermal fentanyl patches, and transmucosal buprenorphine are probably the most commonly used options for providing post-operative analgesia in the early at-home period. However, these require daily administration or are associated with abuse concerns. One of the significant unmet needs in veterinary surgery and pain management is for longer acting opioids for cats to effectively bridge the gap between the in-hospital and at-home recovery periods. A proof of concept study of an extended release formulation of buprenorphine HCL (ER-Bup) was conducted using objective kinetic measures and a unilateral onychectomy model. Using a blinded, randomized, two period crossover design, four cats were allocated to control (saline) or ER-Bup (0.6 mg/kg, subcutaneously [SC]) treatment groups. All animals underwent a unilateral forelimb onychectomy per period with a washout/recovery period in between. Observational pain scores and kinetic data (using a pressure sensitive walkway [PSW]) were collected prior to (baseline) and at intervals for 72 h following surgery. Symmetry indices were derived for kinetic variables (peak vertical force [PVF]; vertical impulse [VI]) of each forelimb for landing following a jump and for walking. A rescue analgesic protocol was in place. Effect of surgery and treatment were evaluated using a mixed model statistical approach. No cats required rescue analgesics based on subjective pain score. ER-Bup had a positive influence on subjective pain scores during the 72 h postsurgery (p = 0.0473). PVF and VI of the operated limb were significantly decreased for both landing (p < 0.0001 and p < 0.0001) and walking (p < 0.0001 and p < 0.0001 respectively) compared to control. ER-Bup resulted in significantly decreased asymmetry in limb use during landing (PVF, p < 0.0001; VI, p < 0.0001) and walking (PVF, p = 0.0002, VI, p < 0.0001). The novel use of data collected
Akeson, Rachel
Measuring the occurrence rate of extrasolar planets is one of the most fundamental constraints on our understanding of planets throughout the Galaxy. By studying planet populations across a wide parameter space in stellar age, type, metallicity, and multiplicity, we can inform planet formation, migration and evolution theories. The ground-based ELTs and the flagship space missions that NASA is planning in the next decades and beyond will be designed to make the first observations of potential biomarkers in the atmospheres of extrasolar planets understanding how common these planets and how they are distributed will be crucial for this effort. One of the most important results of the main Kepler mission was a measurement of the frequency of planets orbiting FGK dwarfs. Although that result is crucial for estimating the frequency of planetary systems orbiting middle-aged Sun-like stars, the majority of stars in the galaxy have lower masses. We propose to extend the Kepler occurrence rates to lower stellar masses by using publicly available data from the second-generation K2 mission to estimate the frequency of planets orbiting low-mass stars. The confluence of the lower temperature, smaller size, and relative abundance of M dwarfs makes them attractive and efficient targets for habitable planet detection and characterization. The archived K2 data contain nearly an order of magnitude more M dwarfs than the original Kepler data set ( 30,000 compared to 3700), allowing us to constrain occurrence rates both more precisely and with more granularity across the M dwarf parameter range. We will also take advantage of the wide variety of stellar environments sampled by the community-driven K2 mission to estimate the frequency of planets orbiting stars with a range of metallicities and ages. The K2 mission has observed several clusters across a wide range of ages, including the Upper Scorpius OB association (10My old), the Pleiades cluster (115My old), and the Hyades and
Directory of Open Access Journals (Sweden)
Kreuchwig Annika
2011-05-01
Full Text Available Abstract Background G protein-coupled receptors (GPCRs transduce a wide variety of extracellular signals to within the cell and therefore have a key role in regulating cell activity and physiological function. GPCR malfunction is responsible for a wide range of diseases including cancer, diabetes and hyperthyroidism and a large proportion of drugs on the market target these receptors. The three dimensional structure of GPCRs is important for elucidating the molecular mechanisms underlying these diseases and for performing structure-based drug design. Although structural data are restricted to only a handful of GPCRs, homology models can be used as a proxy for those receptors not having crystal structures. However, many researchers working on GPCRs are not experienced homology modellers and are therefore unable to benefit from the information that can be gleaned from such three-dimensional models. Here, we present a comprehensive database called the GPCR-SSFE, which provides initial homology models of the transmembrane helices for a large variety of family A GPCRs. Description Extending on our previous theoretical work, we have developed an automated pipeline for GPCR homology modelling and applied it to a large set of family A GPCR sequences. Our pipeline is a fragment-based approach that exploits available family A crystal structures. The GPCR-SSFE database stores the template predictions, sequence alignments, identified sequence and structure motifs and homology models for 5025 family A GPCRs. Users are able to browse the GPCR dataset according to their pharmacological classification or search for results using a UniProt entry name. It is also possible for a user to submit a GPCR sequence that is not contained in the database for analysis and homology model building. The models can be viewed using a Jmol applet and are also available for download along with the alignments. Conclusions The data provided by GPCR-SSFE are useful for investigating
Kuno, Yoshihito; Sakane, Shinya; Kasamatsu, Kenichi; Ichinose, Ikuo; Matsui, Tetsuo
2016-01-01
In this paper, we study atomic quantum simulations of $(1+1)$-dimensional($(1+1)$D) U(1) gauge-Higgs models (GHMs) defined on a lattice. We explain how U(1) lattice GHMs appear from an extended Bose-Hubbard model (EBHM) describing ultra-cold atoms with a nearest neighbor repulsion in a 1D optical lattice. We first study a phase diagram of the 1D EBHM at low fillings by means of a quantum Monte-Carlo(MC) simulation. Next, we study the EBHM at large fillings and also GHMs by the MC simulations in the path-integral formalism and show that there are four phases, i.e., the Higgs phase(superfluid), the confinement phase (Mott insulator), and phases corresponding to the density wave and the supersolid. With the obtained phase diagrams, we investigate the relationship between the two models. Finally, we study real-time dynamic of an electric flux in the GHMs by the Gross-Pitaevskii equations and the truncated Wigner approximation.
Shahmoradi, Leila; Ahmadi, Maryam; Sadoughi, Farahnaz; Piri, Zakieh; Gohari, Mahmood Reza
2015-01-01
A knowledge management audit (KMA) is the first phase in knowledge management implementation. Incomplete or incomprehensive execution of the KMA has caused many knowledge management programs to fail. A study was undertaken to investigate how KMAs are performed systematically in organizations and present a comprehensive model for performing KMAs based on a systematic review. Studies were identified by searching electronic databases such as Emerald, LISA, and the Cochrane library and e-journals such as the Oxford Journal and hand searching of printed journals, theses, and books in the Tehran University of Medical Sciences digital library. The sources used in this study consisted of studies available through the digital library of the Tehran University of Medical Sciences that were published between 2000 and 2013, including both Persian- and English-language sources, as well as articles explaining the steps involved in performing a KMA. A comprehensive model for KMAs is presented in this study. To successfully execute a KMA, it is necessary to perform the appropriate preliminary activities in relation to the knowledge management infrastructure, determine the knowledge management situation, and analyze and use the available data on this situation.
Yang, Weichao; Xu, Kui; Lian, Jijian; Bin, Lingling; Ma, Chao
2018-03-02
Flood is a serious challenge that increasingly affects the residents as well as policymakers. Flood vulnerability assessment is becoming gradually relevant in the world. The purpose of this study is to develop an approach to reveal the relationship between exposure, sensitivity and adaptive capacity for better flood vulnerability assessment, based on the fuzzy comprehensive evaluation method (FCEM) and coordinated development degree model (CDDM). The approach is organized into three parts: establishment of index system, assessment of exposure, sensitivity and adaptive capacity, and multiple flood vulnerability assessment. Hydrodynamic model and statistical data are employed for the establishment of index system; FCEM is used to evaluate exposure, sensitivity and adaptive capacity; and CDDM is applied to express the relationship of the three components of vulnerability. Six multiple flood vulnerability types and four levels are proposed to assess flood vulnerability from multiple perspectives. Then the approach is applied to assess the spatiality of flood vulnerability in Hainan's eastern area, China. Based on the results of multiple flood vulnerability, a decision-making process for rational allocation of limited resources is proposed and applied to the study area. The study shows that multiple flood vulnerability assessment can evaluate vulnerability more completely, and help decision makers learn more information about making decisions in a more comprehensive way. In summary, this study provides a new way for flood vulnerability assessment and disaster prevention decision. Copyright © 2018 Elsevier Ltd. All rights reserved.
The Mouse Tumor Biology Database: A Comprehensive Resource for Mouse Models of Human Cancer.
Krupke, Debra M; Begley, Dale A; Sundberg, John P; Richardson, Joel E; Neuhauser, Steven B; Bult, Carol J
2017-11-01
Research using laboratory mice has led to fundamental insights into the molecular genetic processes that govern cancer initiation, progression, and treatment response. Although thousands of scientific articles have been published about mouse models of human cancer, collating information and data for a specific model is hampered by the fact that many authors do not adhere to existing annotation standards when describing models. The interpretation of experimental results in mouse models can also be confounded when researchers do not factor in the effect of genetic background on tumor biology. The Mouse Tumor Biology (MTB) database is an expertly curated, comprehensive compendium of mouse models of human cancer. Through the enforcement of nomenclature and related annotation standards, MTB supports aggregation of data about a cancer model from diverse sources and assessment of how genetic background of a mouse strain influences the biological properties of a specific tumor type and model utility. Cancer Res; 77(21); e67-70. ©2017 AACR. ©2017 American Association for Cancer Research.
A Comprehensive Model of the Near-Earth Magnetic Field. Phase 3
Sabaka, Terence J.; Olsen, Nils; Langel, Robert A.
2000-01-01
The near-Earth magnetic field is due to sources in Earth's core, ionosphere, magnetosphere, lithosphere, and from coupling currents between ionosphere and magnetosphere and between hemispheres. Traditionally, the main field (low degree internal field) and magnetospheric field have been modeled simultaneously, and fields from other sources modeled separately. Such a scheme, however, can introduce spurious features. A new model, designated CMP3 (Comprehensive Model: Phase 3), has been derived from quiet-time Magsat and POGO satellite measurements and observatory hourly and annual means measurements as part of an effort to coestimate fields from all of these sources. This model represents a significant advancement in the treatment of the aforementioned field sources over previous attempts, and includes an accounting for main field influences on the magnetosphere, main field and solar activity influences on the ionosphere, seasonal influences on the coupling currents, a priori characterization of ionospheric and magnetospheric influence on Earth-induced fields, and an explicit parameterization and estimation of the lithospheric field. The result of this effort is a model whose fits to the data are generally superior to previous models and whose parameter states for the various constituent sources are very reasonable.
A Study of Wind Turbine Comprehensive Operational Assessment Model Based on EM-PCA Algorithm
Zhou, Minqiang; Xu, Bin; Zhan, Yangyan; Ren, Danyuan; Liu, Dexing
2018-01-01
To assess wind turbine performance accurately and provide theoretical basis for wind farm management, a hybrid assessment model based on Entropy Method and Principle Component Analysis (EM-PCA) was established, which took most factors of operational performance into consideration and reach to a comprehensive result. To verify the model, six wind turbines were chosen as the research objects, the ranking obtained by the method proposed in the paper were 4#>6#>1#>5#>2#>3#, which are completely in conformity with the theoretical ranking, which indicates that the reliability and effectiveness of the EM-PCA method are high. The method could give guidance for processing unit state comparison among different units and launching wind farm operational assessment.
Hydrodynamic Instability in an Extended Landau/Levich Model of Liquid-Propellant Combustion
Margolis, Stephen B.; Sackesteder, Kurt (Technical Monitor)
1998-01-01
The classical Landau/Levich models of liquid propellant combustion, which serve as seminal examples of hydrodynamic instability in reactive systems, have been combined and extended to account for a dynamic dependence, absent in the original formulations, of the local burning rate on the local pressure and/or temperature fields. The resulting model admits an extremely rich variety of both hydrodynamic and reactive/diffusive instabilities that can be analyzed in various limiting parameter regimes. In the present work, a formal asymptotic analysis, based on the realistic smallness of the gas-to-liquid density ratio, is developed to investigate the combined effects of gravity, surface tension and viscosity on the hydrodynamic instability of the propagating liquid/gas interface. In particular, a composite asymptotic expression, spanning three distinguished wavenumber regimes, is derived for both cellular and pulsating hydrodynamic neutral stability boundaries A(sub p)(k), where A(sub p) is the pressure sensitivity of the burning rate and k is the disturbance wavenumber. For the case of cellular (Landau) instability, the results demonstrate explicitly the stabilizing effect of gravity on long-wave disturbances, the stabilizing effect of viscosity and surface tension on short-wave perturbations, and the instability associated with intermediate wavenumbers for critical negative values of A(sub p). In the limiting case of weak gravity, it is shown that cellular hydrodynamic instability in this context is a long-wave instability phenomenon, whereas at normal gravity, this instability is first manifested through O(l) wavenumber disturbances. It is also demonstrated that, in the large wavenumber regime, surface tension and both liquid and gas viscosity all produce comparable stabilizing effects in the large-wavenumber regime, thereby providing significant modifications to previous analyses of Landau instability in which one or more of these effects were neglected. In contrast
Evaluation of CAMEL - comprehensive areal model of earthquake-induced landslides
Miles, S.B.; Keefer, D.K.
2009-01-01
A new comprehensive areal model of earthquake-induced landslides (CAMEL) has been developed to assist in planning decisions related to disaster risk reduction. CAMEL provides an integrated framework for modeling all types of earthquake-induced landslides using fuzzy logic systems and geographic information systems. CAMEL is designed to facilitate quantitative and qualitative representation of terrain conditions and knowledge about these conditions on the likely areal concentration of each landslide type. CAMEL has been empirically evaluated with respect to disrupted landslides (Category I) using a case study of the 1989 M = 6.9 Loma Prieta, CA earthquake. In this case, CAMEL performs best in comparison to disrupted slides and falls in soil. For disrupted rock fall and slides, CAMEL's performance was slightly poorer. The model predicted a low occurrence of rock avalanches, when none in fact occurred. A similar comparison with the Loma Prieta case study was also conducted using a simplified Newmark displacement model. The area under the curve method of evaluation was used in order to draw comparisons between both models, revealing improved performance with CAMEL. CAMEL should not however be viewed as a strict alternative to Newmark displacement models. CAMEL can be used to integrate Newmark displacements with other, previously incompatible, types of knowledge. ?? 2008 Elsevier B.V.
Toward a comprehensive, theoretical model of compassion fatigue: An integrative literature review.
Coetzee, Siedine K; Laschinger, Heather K S
2017-11-20
This study was an integrative literature review in relation to compassion fatigue models, appraising these models, and developing a comprehensive theoretical model of compassion fatigue. A systematic search on PubMed, EbscoHost (Academic Search Premier, E-Journals, Medline, PsycINFO, Health Source Nursing/Academic Edition, CINAHL, MasterFILE Premier and Health Source Consumer Edition), gray literature, and manual searches of included reference lists was conducted in 2016. The studies (n = 11) were analyzed, and the strengths and limitations of the compassion fatigue models identified. We further built on these models through the application of the conservation of resources theory and the social neuroscience of empathy. The compassion fatigue model shows that it is not empathy that puts nurses at risk of developing compassion fatigue, but rather a lack of resources, inadequate positive feedback, and the nurse's response to personal distress. By acting on these three aspects, the risk of developing compassion fatigue can be addressed, which could improve the retention of a compassionate and committed nurse workforce. © 2017 John Wiley & Sons Australia, Ltd.
An EMTP Comprehensive Model of Tower Grounding and its Simulation Analysis
Wang, Zicheng; Zhang, Yadong; Guo, Jin; Luo, Rong
2017-05-01
For the purpose of designing the grounding device of the poles and towers an improved EMTP model is put forward in this paper. The impulse characteristics of the tower grounding under impulse currents are simulated and analysed based on circuit theory. Only the non-linear effects caused by soil ionization are considered in the current studies. And the interactions deriving from the coexistence of segmented grounding electrodes have been neglected. Consequently, the calculated results of the impulse grounding resistance of the complex grounding device such as the tower grounding are not enough accurate using the traditional models. The soil ionization effects are simulated through the non-linear resistance. The current-controlled voltage sources are introduced in the model to take into account the interactions of the segmented grounding electrodes. Then the comprehensive model of the tower grounding is established. Comparison of simulation results with experimental data implies that the tower grounding model proposed in this paper is more accurate and effective than the traditional model.
Energy Technology Data Exchange (ETDEWEB)
Sakai, T [Synchrotron Radiation Research Center, Japan Atomic Energy Agency (JAEA), SPring-8, Hyogo 679-5148 and CREST, JST (Japan)], E-mail: sakai@spring8.or.jp
2008-03-15
The phonon effect of the in-plane oxygen breathing vibration in the high-Tc cuprates is investigated by the numerical diagonalization of an extended t-J-Holstein model, including the modulation of t. As a result, it is found that if the modulation of t due to the phonon is sufficiently large, the breathing mode possibly stabilizes the superconductivity.
Directory of Open Access Journals (Sweden)
Shouyan Jiang
2017-01-01
Full Text Available We model the fluid flow within the crack as one-dimensional flow and assume that the flow is laminar; the fluid is incompressible and accounts for the time-dependent rate of crack opening. Here, we discretise the flow equation by finite volume methods. The extended finite element methods are used for solving solid medium with crack under dynamic loads. Having constructed the approximation of dynamic extended finite element methods, the derivation of governing equation for dynamic extended finite element methods is presented. The implicit time algorithm is elaborated for the time descritisation of dominant equation. In addition, the interaction integral method is given for evaluating stress intensity factors. Then, the coupling model for modelling hydraulic fracture can be established by the extended finite element methods and the finite volume methods. We compare our present numerical results with our experimental results for verifying the proposed model. Finally, we investigate the water pressure distribution along crack surface and the effect of water pressure distribution on the fracture property.
The Agricultural Policy/Environmental eXtender (APEX) is a watershed-scale water quality model that includes detailed representation of agricultural management but currently does not have microbial fate and transport simulation capabilities. The objective of this work was to develop a process-based ...
2015-02-01
The Maryland State Highway Administration (SHA) has initiated major planning efforts to improve transportation : efficiency, safety, and sustainability on critical highway corridors through its Comprehensive Highway Corridor : (CHC) program. This pro...
Directory of Open Access Journals (Sweden)
R. Mathur
2017-10-01
Full Text Available The Community Multiscale Air Quality (CMAQ modeling system is extended to simulate ozone, particulate matter, and related precursor distributions throughout the Northern Hemisphere. Modeled processes were examined and enhanced to suitably represent the extended space and timescales for such applications. Hemispheric-scale simulations with CMAQ and the Weather Research and Forecasting (WRF model are performed for multiple years. Model capabilities for a range of applications including episodic long-range pollutant transport, long-term trends in air pollution across the Northern Hemisphere, and air pollution–climate interactions are evaluated through detailed comparison with available surface, aloft, and remotely sensed observations. The expansion of CMAQ to simulate the hemispheric scales provides a framework to examine interactions between atmospheric processes occurring on various spatial and temporal scales with physical, chemical, and dynamical consistency.
A comprehensive and systematic evaluation framework for a parsimonious daily rainfall field model
Bennett, Bree; Thyer, Mark; Leonard, Michael; Lambert, Martin; Bates, Bryson
2018-01-01
The spatial distribution of rainfall has a significant influence on catchment dynamics and the generation of streamflow time series. However, there are few stochastic models that can simulate long sequences of stochastic rainfall fields continuously in time and space. To address this issue, the first goal of this study was to present a new parsimonious stochastic model that produces daily rainfall fields across the catchment. To achieve parsimony, the model used the latent-variable approach (because this parsimoniously simulates rainfall occurrences as well as amounts) and several other assumptions (including contemporaneous and separable spatiotemporal covariance structures). The second goal was to develop a comprehensive and systematic evaluation (CASE) framework to identify model strengths and weaknesses. This included quantitative performance categorisation that provided a systematic, succinct and transparent method to assess and summarise model performance over a range of statistics, sites, scales and seasons. The model is demonstrated using a case study from the Onkaparinga catchment in South Australia. The model showed many strengths in reproducing the observed rainfall characteristics with the majority of statistics classified as either statistically indistinguishable from the observed or within 5% of the observed across the majority of sites and seasons. These included rainfall occurrences/amounts, wet/dry spell distributions, annual volumes/extremes and spatial patterns, which are important from a hydrological perspective. One of the few weaknesses of the model was that the total annual rainfall in dry years (lower 5%) was overestimated by 15% on average over all sites. An advantage of the CASE framework was that it was able to identify the source of this overestimation was poor representation of the annual variability of rainfall occurrences. Given the strengths of this continuous daily rainfall field model it has a range of potential hydrological
Isms dimensions: toward a more comprehensive and integrative model of belief-system components.
Saucier, Gerard
2013-05-01
Psychological research on beliefs, values, worldview, and ideology has been limited by inadequate structural models to organize the plethora of constructs. The present studies investigate the potential of a dimensional model based on lexical, dictionary-represented -ism concepts to form an organizing structural model. Four isms factors found previously in college samples are shown to replicate in community-sample data with better controls for acquiescent responding. But analyses also reveal a 5th factor involving egalitarianism and inequality-aversion, increasing the comprehensiveness of the structural model. Relations of frequently used constructs (values, authoritarianism, social dominance orientation) to the isms dimensions are detailed, demonstrating both the integrative and value-adding potentials of the model. The possibility of potential additional nonlexical factors (Trust in Government, Ethnocentrism, Xenophobia, and Nativism) is evaluated. Factors identified in these studies are demonstrated to show interesting relations with political-party preference, subjective well-being, and change over time in the Big Five personality dimensions. PsycINFO Database Record (c) 2013 APA, all rights reserved
Directory of Open Access Journals (Sweden)
Hadi Kalantari
2015-08-01
Full Text Available Background and Objectives: In all health systems, maternity health program has an important role for its great effects. Therefore, the evaluation of this program constantly was at the center of attention of managers and policy makers. The current study aimed to analyze maternity health program by focusing on the evaluation process according to the evaluation comprehensive model (CIPPI in East Azarbaijan. Material and Methods: This is a descriptive cross-sectional study and its data were collected by qualitative methods such as observing and interviewing. By evaluating different levels of delivered services, interviewing process owners and customers and reviewing the documents, evaluation process was studied and the results were compared with CIPPI model. Results: The yielded results from the comparison of this program with CIPPI model indicated that from 24 analyzed items in 5 dimensions of this program, only 5 items were measured completely, 5 items measured partially and 14 items were not measured at all. There were other problems including weaknesses in checklist, standards and during the process of evaluation. Conclusion: According to the results, it is concluded that the current model of maternity health evaluation program in Eastern Azarbaijan has a notable gap with an ideal evaluation program and the need for a revise of this program according to efficient and effective evaluation models seems necessary.
A comprehensive energy and mass balance firn model for simulations over multiple glacial cycles
Imhof, Michael; Born, Andreas; Stocker, Thomas
2017-04-01
We present a fast yet physically comprehensive glacier surface mass balance model capable of simulations that cover the entire Northern Hemisphere over several glacial cycles. Fluxes of energy and mass are calculated between the atmosphere and a multilayer snow cover, including internal processes like densification and water percolation as well as snow and ice melt. The model is especially designed to provide upper boundary conditions to force ice sheet models on time scales of up to 106 years. To achieve a high numerical efficiency, the model employs a variable time stepping scheme on the grid point level and a Lagrangian grid attached to the snow mass. The input variables are short wave radiation, air temperature and precipitation with half-weekly or daily time steps. This new surface mass balance model has been tested in extensive ensemble simulations and yields realistic representations of present-day ice sheets. The extent of the intra-annual snow cover on the Northern Hemisphere correlates temporally and spatially well with satellite measurements. Perennial firn aquifers are simulated realistically in Greenland and the simulated densification and snow temperature at two bore hole sites in central Greenland yield promising results.
The comprehensive diagnostic study is suggested as a design to model the diagnostic process.
Donner-Banzhoff, Norbert; Haasenritter, Jörg; Hüllermeier, Eyke; Viniol, Annika; Bösner, Stefan; Becker, Annette
2014-02-01
The classical diagnostic cross-sectional study has a focus on one disease only. Generalist clinicians, however, are confronted with a wide range of diagnoses. We propose the "comprehensive diagnostic study design" to evaluate diagnostic tests regarding more than one disease outcome. We present the secondary analysis of a data set obtained from patients presenting with chest pain in primary care. Participating clinicians recorded 42 items of the history and physical examination. Diagnostic outcomes were reviewed by an independent panel after 6-month follow-up (n = 710 complete cases). We used Shannon entropy as a measure of uncertainty before and after testing. Four different analytical strategies modeling specific clinical ways of reasoning were evaluated. Although the "global entropy" strategy reduced entropy most, it is unlikely to be of clinical use because of its complexity. "Inductive" and "fixed-set" strategies turned out to be efficient requiring a small amount of data only. The "deductive" procedure resulted in the smallest reduction of entropy. We suggest that the comprehensive diagnostic study design is a feasible and valid option to improve our understanding of the diagnostic process. It is also promising as a justification for clinical recommendations. Copyright © 2014 Elsevier Inc. All rights reserved.
DEFF Research Database (Denmark)
Garcia, Ada V.; Thomsen, Kaj; Stenby, Erling Halfdan
2005-01-01
Pressure parameters are added to the Extended UNIQUAC model presented by Thomsen and Rasmussen (1999). The improved model has been used for correlation and prediction of solid-liquid equilibrium (SLE) of scaling minerals (CaSO4, CaSO4·2H2O, BaSO4 and SrSO4) at temperatures up to 300°C and pressur...
Extending Galactic Habitable Zone Modelling to Include the Emergence of Intelligent Life
Morrison, I. S.; Gowanlock, M. G.
2014-03-01
Previous studies of the Galactic Habitable Zone (GHZ) have been concerned with identifying those regions of the Galaxy that may favour the emergence of "complex life" - typically defined to be land-based life. A planet is deemed "habitable" if it meets a set of assumed criteria for supporting the emergence of such complex life. The notion of the GHZ, and the premise that sufficient chemical evolution is required for planet formation, was quantified by Gonzalez et al. (2001). This work was later broadened to include dangers to the formation and habitability of terrestrial planets by Lineweaver et al. (2004) and then studied using a Monte Carlo simulation on the resolution of individual stars in the previous work of Gowanlock et al. (2011). The model developed in the latter work considers the stellar number density distribution and formation history of the Galaxy, planet formation mechanisms and the hazards to planetary biospheres as a result of supernova sterilization events that take place in the vicinity of the planets. Based on timescales taken from the origin and evolution of complex life on Earth, the model suggests large numbers of potentially habitable planets exist in our Galaxy, with the greatest concentration likely being towards the inner Galaxy. In this work we extend the assessment of habitability to consider the potential for life to further evolve on habitable planets to the point of intelligence - which we term the propensity for the emergence of intelligent life. We assume the propensity is strongly influenced by the time durations available for evolutionary processes to proceed undisturbed by the "resetting" effect of nearby supernovae. The model of Gowanlock et al. (2011) is used to produce a representative population of habitable planets by matching major observable properties of the Milky Way. Account is taken of the birth and death dates of each habitable planet and the timing of supernova events in each planet's vicinity. The times between
ANALISIS BELANJA ONLINE MELALUI SMARTPHONE DENGAN MENGGUNAKAN EXTENDED TECHNOLOGY ACCEPTANCE MODEL
Directory of Open Access Journals (Sweden)
Nining Heriyanti
2016-04-01
appropriate marketing strategies to take advantage of both the perpetrator marketing of new marketing channels, namely smart phones as shopping online media. Originality of this research is specifically discusses online shopping on one device, especially smart phones are still rare. Keyword:Online shopping, extended technology acceptance model
Directory of Open Access Journals (Sweden)
M. Bangert
2011-05-01
Full Text Available We have extended the coupled mesoscale atmosphere and chemistry model COSMO-ART to account for the transformation of aerosol particles into cloud condensation nuclei and to quantify their interaction with warm cloud microphysics on the regional scale. The new model system aims to fill the gap between cloud resolving models and global scale models. It represents the very complex microscale aerosol and cloud physics as detailed as possible, whereas the continental domain size and efficient codes will allow for both studying weather and regional climate. The model system is applied in a first extended case study for Europe for a cloudy five day period in August 2005.
The model results show that the mean cloud droplet number concentration of clouds is correlated with the structure of the terrain, and we present a terrain slope parameter TS to classify this dependency. We propose to use this relationship to parameterize the probability density function, PDF, of subgrid-scale cloud updraft velocity in the activation parameterizations of climate models.
The simulations show that the presence of cloud condensation nuclei (CCN and clouds are closely related spatially. We find high aerosol and CCN number concentrations in the vicinity of clouds at high altitudes. The nucleation of secondary particles is enhanced above the clouds. This is caused by an efficient formation of gaseous aerosol precursors above the cloud due to more available radiation, transport of gases in clean air above the cloud, and humid conditions. Therefore the treatment of complex photochemistry is crucial in atmospheric models to simulate the distribution of CCN.
The mean cloud droplet number concentration and droplet diameter showed a close link to the change in the aerosol. To quantify the net impact of an aerosol change on the precipitation we calculated the precipitation susceptibility β for the whole model domain over a period of two days with
Fersch, Benjamin; Senatore, Alfonso; Kunstmann, Harald
2017-04-01
Fully-coupled hydrometeorological modeling enables investigations about the complex and often non-linear exchange mechanisms among subsurface, land, and atmosphere with respect to water and energy fluxes. The consideration of lateral redistribution of surface and subsurface water in such modeling systems is a crucial enhancement, allowing for a better representation of surface spatial patterns and providing also channel discharge predictions. However, the evaluation of fully-coupled simulations is difficult since the amount of physical detail along with feedback mechanisms leads to high degrees of freedom. Therefore, comprehensive observation data is required to obtain meaningful model configurations. We present a case study for a medium-sized river catchment in southern Germany that includes the calibration of the stand-alone and the evaluation of the fully-coupled WRF-Hydro modeling system with a horizontal resolution of 1 x 1 km2, for the period June to August 2015. ECMWF ERA-Interim reanalysis is used for model driving. Land-surface processes are represented by the Noah-MP land surface model. Land-cover is described by the EU CORINE data set. Observations for model evaluation are obtained from the TERENO Pre-Alpine observatory (http://www.imk-ifu.kit.edu/tereno.php) and are complemented by further measurements from the ScaleX campaign (http://scalex.imk-ifu.kit.edu) such as atmospheric profiles obtained from radiometer sounding and airborne systems as well as soil moisture and -temperature networks. We show how well water budgets and heat-fluxes are being reproduced by the stand-alone WRF, the stand-alone WRF-Hydro and the fully-coupled WRF-Hydro model.
Performance Modelling of Automatic Identification System with Extended Field of View
DEFF Research Database (Denmark)
Lauersen, Troels; Mortensen, Hans Peter; Pedersen, Nikolaj Bisgaard
2010-01-01
This paper deals with AIS (Automatic Identification System) behavior, to investigate the severity of packet collisions in an extended field of view (FOV). This is an important issue for satellite-based AIS, and the main goal is a feasibility study to find out to what extent an increased FOV...
Strahm, Ivo; Munz, Nicole; Braun, Christian; Gälli, René; Leu, Christian; Stamm, Christian
2014-05-01
Water quality in the Swiss river network is affected by many micropollutants from a variety of diffuse sources. This study compares, for the first time, in a comprehensive manner the diffuse sources and the substance groups that contribute the most to water contamination in Swiss streams and highlights the major regions for water pollution. For this a simple but comprehensive model was developed to estimate emission from diffuse sources for the entire Swiss river network of 65 000 km. Based on emission factors the model calculates catchment specific losses to streams for more than 15 diffuse sources (such as crop lands, grassland, vineyards, fruit orchards, roads, railways, facades, roofs, green space in urban areas, landfills, etc.) and more than 130 different substances from 5 different substance groups (pesticides, biocides, heavy metals, human drugs, animal drugs). For more than 180 000 stream sections estimates of mean annual pollutant loads and mean annual concentration levels were modeled. This data was validated with a set of monitoring data and evaluated based on annual average environmental quality standards (AA-EQS). Model validation showed that the estimated mean annual concentration levels are within the range of measured data. Therefore simulations were considered as adequately robust for identifying the major sources of diffuse pollution. The analysis depicted that in Switzerland widespread pollution of streams can be expected. Along more than 18 000 km of the river network one or more simulated substances has a concentration exceeding the AA-EQS. In single stream sections it could be more than 50 different substances. Moreover, the simulations showed that in two-thirds of small streams (Strahler order 1 and 2) at least one AA-EQS is always exceeded. The highest number of substances exceeding the AA-EQS are in areas with large fractions of arable cropping, vineyards and fruit orchards. Urban areas are also of concern even without considering
A Fuzzy Comprehensive Evaluation Model for Sustainability Risk Evaluation of PPP Projects
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Libiao Bai
2017-10-01
Full Text Available Evaluating the sustainability risk level of public–private partnership (PPP projects can reduce project risk incidents and achieve the sustainable development of the organization. However, the existing studies about PPP projects risk management mainly focus on exploring the impact of financial and revenue risks but ignore the sustainability risks, causing the concept of “sustainability” to be missing while evaluating the risk level of PPP projects. To evaluate the sustainability risk level and achieve the most important objective of providing a reference for the public and private sectors when making decisions on PPP project management, this paper constructs a factor system of sustainability risk of PPP projects based on an extensive literature review and develops a mathematical model based on the methods of fuzzy comprehensive evaluation model (FCEM and failure mode, effects and criticality analysis (FMECA for evaluating the sustainability risk level of PPP projects. In addition, this paper conducts computational experiment based on a questionnaire survey to verify the effectiveness and feasibility of this proposed model. The results suggest that this model is reasonable for evaluating the sustainability risk level of PPP projects. To our knowledge, this paper is the first study to evaluate the sustainability risk of PPP projects, which would not only enrich the theories of project risk management, but also serve as a reference for the public and private sectors for the sustainable planning and development. Keywords: sustainability risk eva
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Tuan Anh Nguyen
2014-01-01
Full Text Available It is important to assess availability of virtualized systems in IT business infrastructures. Previous work on availability modeling and analysis of the virtualized systems used a simplified configuration and assumption in which only one virtual machine (VM runs on a virtual machine monitor (VMM hosted on a physical server. In this paper, we show a comprehensive availability model using stochastic reward nets (SRN. The model takes into account (i the detailed failures and recovery behaviors of multiple VMs, (ii various other failure modes and corresponding recovery behaviors (e.g., hardware faults, failure and recovery due to Mandelbugs and aging-related bugs, and (iii dependency between different subcomponents (e.g., between physical host failure and VMM, etc. in a virtualized servers system. We also show numerical analysis on steady state availability, downtime in hours per year, transaction loss, and sensitivity analysis. This model provides a new finding on how to increase system availability by combining both software rejuvenations at VM and VMM in a wise manner.
PALADYN, a comprehensive land surface-vegetation-carbon cycle model of intermediate complexity
Willeit, Matteo; Ganopolski, Andrey
2016-04-01
PALADYN is presented, a new comprehensive and computationally efficient land surface-vegetation-carbon cycle model designed to be used in Earth system models of intermediate complexity for long-term simulations and paleoclimate studies. The model treats in a consistent manner the interaction between atmosphere, terrestrial vegetation and soil through the fluxes of energy, water and carbon. Energy, water and carbon are conserved. The model explicitly treats permafrost, both in physical processes and as important carbon pool. The model distinguishes 9 surface types of which 5 are different vegetation types, bare soil, land ice, lake and ocean shelf. Including the ocean shelf allows to treat continuous changes in sea level and shelf area associated with glacial cycles. Over each surface type the model solves the surface energy balance and computes the fluxes of sensible, latent and ground heat and upward shortwave and longwave radiation. It includes a single snow layer. The soil model distinguishes between three different macro surface types which have their own soil column: vegetation and bare soil, ice sheet and ocean shelf. The soil is vertically discretized into 5 layers where prognostic equations for temperature, water and carbon are consistently solved. Phase changes of water in the soil are explicitly considered. A surface hydrology module computes precipitation interception by vegetation, surface runoff and soil infiltration. The soil water equation is based on Darcy's law. Given soil water content, the wetland fraction is computed based on a topographic index. Photosynthesis is computed using a light use efficiency model. Carbon assimilation by vegetation is coupled to the transpiration of water through stomatal conductance. The model includes a dynamic vegetation module with 5 plant functional types competing for the gridcell share with their respective net primary productivity. Each macro surface type has its own carbon pools represented by a litter, a fast
Directory of Open Access Journals (Sweden)
Megan A Cummins
2014-03-01
Full Text Available Reverse rate dependence is a problematic property of antiarrhythmic drugs that prolong the cardiac action potential (AP. The prolongation caused by reverse rate dependent agents is greater at slow heart rates, resulting in both reduced arrhythmia suppression at fast rates and increased arrhythmia risk at slow rates. The opposite property, forward rate dependence, would theoretically overcome these parallel problems, yet forward rate dependent (FRD antiarrhythmics remain elusive. Moreover, there is evidence that reverse rate dependence is an intrinsic property of perturbations to the AP. We have addressed the possibility of forward rate dependence by performing a comprehensive analysis of 13 ventricular myocyte models. By simulating populations of myocytes with varying properties and analyzing population results statistically, we simultaneously predicted the rate-dependent effects of changes in multiple model parameters. An average of 40 parameters were tested in each model, and effects on AP duration were assessed at slow (0.2 Hz and fast (2 Hz rates. The analysis identified a variety of FRD ionic current perturbations and generated specific predictions regarding their mechanisms. For instance, an increase in L-type calcium current is FRD when this is accompanied by indirect, rate-dependent changes in slow delayed rectifier potassium current. A comparison of predictions across models identified inward rectifier potassium current and the sodium-potassium pump as the two targets most likely to produce FRD AP prolongation. Finally, a statistical analysis of results from the 13 models demonstrated that models displaying minimal rate-dependent changes in AP shape have little capacity for FRD perturbations, whereas models with large shape changes have considerable FRD potential. This can explain differences between species and between ventricular cell types. Overall, this study provides new insights, both specific and general, into the determinants of
DEFF Research Database (Denmark)
Boiocchi, Riccardo; Sin, Gürkan; Gernaey, Krist V.
2015-01-01
In this work the Benchmark Simulation Model No.2 is extended with processes for nitrous oxide production and for side-stream partial nitritation/Anammox (PN/A) treatment. For these extensions the Activated Sludge Model for Greenhouse gases No.1 was used to describe the main waterline, whereas...... increased the total nitrogen removal by 10%; (ii) reduced the aeration demand by 16% compared to the base case, and (iii) the activity of ammonia-oxidizing bacteria is most influencing nitrous oxide emissions. The extended model provides a simulation platform to generate, test and compare novel control...... strategies to improve operation performance and to meet the new plant performance criteria such as minimization of greenhouse gas (in particular of nitrous oxide) emissions....
Marr, T David; Pinelli, Nicole R; Jarmul, Jamie A; Waldron, Kayla M; Eckel, Stephen F; Cicci, Jonathan D; Bates, Jill S; Amerine, Lindsey B
2017-10-01
Pharmacy practice models that foster pharmacists' accountability for medication-related outcomes are imperative for the profession. Comprehensive medication management (CMM) is an opportunity to advance patient care. The objective of this study was to evaluate the impact of a CMM practice model in the acute care setting on organizational, patient, and financial outcomes. Three adult service lines focused on at-risk patients identified using internal risk stratification methodology were implemented. Core CMM elements included medication reconciliation, differentiated clinical pharmacy services, inpatient MTM consultations, discharge services, and documentation. Mixed methods compared the effect of the CMM model before and after implementation. Historical patients served as comparative controls in an observational design. Pharmacists completed a 60-minute interview regarding their experiences. Qualitative data were analyzed using thematic coding to characterize perception of the model. Three pharmacists implemented the model on cardiology, hematology/oncology, and surgery transplant services and provided services to 75 patients during the study. A total of 145 medication-related problems were identified and resolved. CMM was associated with a nonsignificant reduction of 8.8% in 30-day hospital readmission rates ( P = 0.64) and a 24.9% reduction in 30-day hospital utilization ( P = 0.41) as well as a significant reduction of 86.5% in emergency department visits ( P = 0.02). Patients receiving discharge prescriptions from our outpatient pharmacies increased by 21.4%, resulting in an 11.3% increase in discharge prescription capture and additional revenue of $5780. Themes identified from qualitative interviews included CMM structure, challenges, value, and resources. This study demonstrated successful implementation of a CMM model that positively affected organizational, patient, and financial outcomes.
Jerrold E. Winandy
2000-01-01
One of the most, if not the most, efficient methods of extending our existing forest resource is to prolong the service life of wood currently in-service by using those existing structures to meet our future needs (Hamilton and Winandy 1998). It is currently estimated that over 7 x 109 m3 (3 trillion bd. ft) of wood is currently in service within the United States of...
Xiong, Guanglei; Sun, Peng; Zhou, Haoyin; Ha, Seongmin; Hartaigh, Briain O; Truong, Quynh A; Min, James K
2017-02-01
In clinical cardiology, both anatomy and physiology are needed to diagnose cardiac pathologies. CT imaging and computer simulations provide valuable and complementary data for this purpose. However, it remains challenging to gain useful information from the large amount of high-dimensional diverse data. The current tools are not adequately integrated to visualize anatomic and physiologic data from a complete yet focused perspective. We introduce a new computer-aided diagnosis framework, which allows for comprehensive modeling and visualization of cardiac anatomy and physiology from CT imaging data and computer simulations, with a primary focus on ischemic heart disease. The following visual information is presented: (1) Anatomy from CT imaging: geometric modeling and visualization of cardiac anatomy, including four heart chambers, left and right ventricular outflow tracts, and coronary arteries; (2) Function from CT imaging: motion modeling, strain calculation, and visualization of four heart chambers; (3) Physiology from CT imaging: quantification and visualization of myocardial perfusion and contextual integration with coronary artery anatomy; (4) Physiology from computer simulation: computation and visualization of hemodynamics (e.g., coronary blood velocity, pressure, shear stress, and fluid forces on the vessel wall). Substantially, feedback from cardiologists have confirmed the practical utility of integrating these features for the purpose of computer-aided diagnosis of ischemic heart disease.
Comprehensive model of annual plankton succession based on the whole-plankton time series approach.
Romagnan, Jean-Baptiste; Legendre, Louis; Guidi, Lionel; Jamet, Jean-Louis; Jamet, Dominique; Mousseau, Laure; Pedrotti, Maria-Luiza; Picheral, Marc; Gorsky, Gabriel; Sardet, Christian; Stemmann, Lars
2015-01-01
Ecological succession provides a widely accepted description of seasonal changes in phytoplankton and mesozooplankton assemblages in the natural environment, but concurrent changes in smaller (i.e. microbes) and larger (i.e. macroplankton) organisms are not included in the model because plankton ranging from bacteria to jellies are seldom sampled and analyzed simultaneously. Here we studied, for the first time in the aquatic literature, the succession of marine plankton in the whole-plankton assemblage that spanned 5 orders of magnitude in size from microbes to macroplankton predators (not including fish or fish larvae, for which no consistent data were available). Samples were collected in the northwestern Mediterranean Sea (Bay of Villefranche) weekly during 10 months. Simultaneously collected samples were analyzed by flow cytometry, inverse microscopy, FlowCam, and ZooScan. The whole-plankton assemblage underwent sharp reorganizations that corresponded to bottom-up events of vertical mixing in the water-column, and its development was top-down controlled by large gelatinous filter feeders and predators. Based on the results provided by our novel whole-plankton assemblage approach, we propose a new comprehensive conceptual model of the annual plankton succession (i.e. whole plankton model) characterized by both stepwise stacking of four broad trophic communities from early spring through summer, which is a new concept, and progressive replacement of ecological plankton categories within the different trophic communities, as recognised traditionally.
A Comprehensive Breath Plume Model for Disease Transmission via Expiratory Aerosols
Halloran, S. K.; Wexler, A. S.; Ristenpart, W. D.
2012-11-01
The peak in influenza incidence during wintertime represents a longstanding unresolved scientific question. One hypothesis is that the efficacy of airborne transmission via aerosols is increased at low humidity and temperature, conditions that prevail in wintertime. Recent experiments with guinea pigs suggest that transmission is indeed maximized at low humidity and temperature, a finding which has been widely interpreted in terms of airborne influenza virus survivability. This interpretation, however, neglects the effect of the airflow on the transmission probability. Here we provide a comprehensive model for assessing the probability of disease transmission via expiratory aerosols between test animals in laboratory conditions. The spread of aerosols emitted from an infected animal is modeled using dispersion theory for a homogeneous turbulent airflow. The concentration and size distribution of the evaporating droplets in the resulting ``Gaussian breath plume'' are calculated as functions of downstream position. We demonstrate that the breath plume model is broadly consistent with the guinea pig experiments, without invoking airborne virus survivability. Moreover, the results highlight the need for careful characterization of the airflow in airborne transmission experiments.
DEFF Research Database (Denmark)
A computer game's player is experiencing not only the game as a designer-made artefact, but also a multitude of social and cultural practices and contexts of both computer game play and everyday life. As a truly multidisciplinary anthology, Extending Experiences sheds new light on the mesh...... of possibilities and influences the player engages with. Part one, Experiential Structures of Play, considers some of the key concepts commonly used to address the experience of a computer game player. The second part, Bordering Play, discusses conceptual and practical overlaps of games and everyday life...... and the impacts of setting up, crossing and breaking the boundaries of game and non-game. Part three, Interfaces of Play, looks at games as technological and historical artefacts and commodities. The fourth part, Beyond Design, introduces new models for the practical and theoretical dimensions of game design....
Extended icosahedral structures
Jaric, Marko V
1989-01-01
Extended Icosahedral Structures discusses the concepts about crystal structures with extended icosahedral symmetry. This book is organized into six chapters that focus on actual modeling of extended icosahedral crystal structures. This text first presents a tiling approach to the modeling of icosahedral quasiperiodic crystals. It then describes the models for icosahedral alloys based on random connections between icosahedral units, with particular emphasis on diffraction properties. Other chapters examine the glassy structures with only icosahedral orientational order and the extent of tra
Directory of Open Access Journals (Sweden)
Sangjun Park
2013-12-01
Full Text Available A power-based vehicle fuel consumption model, entitled the Virginia Tech Comprehensive Power-based Fuel Consumption Model (VT-CPFM that was developed in an earlier publication is validated against in-field fuel consumption measurements. The study demonstrates that the VT-CPFMs calibrated using the EPA city and highway fuel economy ratings generally provide reliable fuel consumption estimates with a coefficient of determination in the range of 0.96. More importantly, both estimates and measurements produce very similar behavioral changes depending on engine load conditions. The VT-CPFMs are demonstrated to be easily calibrated using publically available data without the need to gather in-field instantaneous data.
Yang, Xiaoxia; Duan, John; Fisher, Jeffrey
2016-01-01
A previously presented physiologically-based pharmacokinetic model for immediate release (IR) methylphenidate (MPH) was extended to characterize the pharmacokinetic behaviors of oral extended release (ER) MPH formulations in adults for the first time. Information on the anatomy and physiology of the gastrointestinal (GI) tract, together with the biopharmaceutical properties of MPH, was integrated into the original model, with model parameters representing hepatic metabolism and intestinal non-specific loss recalibrated against in vitro and in vivo kinetic data sets with IR MPH. A Weibull function was implemented to describe the dissolution of different ER formulations. A variety of mathematical functions can be utilized to account for the engineered release/dissolution technologies to achieve better model performance. The physiological absorption model tracked well the plasma concentration profiles in adults receiving a multilayer-release MPH formulation or Metadate CD, while some degree of discrepancy was observed between predicted and observed plasma concentration profiles for Ritalin LA and Medikinet Retard. A local sensitivity analysis demonstrated that model parameters associated with the GI tract significantly influenced model predicted plasma MPH concentrations, albeit to varying degrees, suggesting the importance of better understanding the GI tract physiology, along with the intestinal non-specific loss of MPH. The model provides a quantitative tool to predict the biphasic plasma time course data for ER MPH, helping elucidate factors responsible for the diverse plasma MPH concentration profiles following oral dosing of different ER formulations. PMID:27723791
Petscher, Yaacov; Justice, Laura M; Hogan, Tiffany
2017-07-05
This study examined change in early language comprehension from 15 to 54 months for fifth-grade typical readers (n = 35), poor decoders (n = 11), or poor comprehenders (n = 16) from a nationally representative study of early child-care experiences. Changing measures of language comprehension were captured across early childhood for the 62 children. Multiple-group quasi-simplex and latent growth models were used on rank-transformed outcomes to examine children's relative rank change. Results showed that future poor comprehenders significantly declined in language comprehension over time relative to others who gradually improved. Efforts to improve language skills as a means to improve reading comprehension hinge upon the perspective that language weaknesses are a causal contributor to reading difficulties. © 2017 The Authors. Child Development © 2017 Society for Research in Child Development, Inc.
National Research Council Canada - National Science Library
Pan, Xinyi; Li, Cheng; Li, Kuncheng; Ying, Kui; Weng, Dehe; Qin, Wen
2010-01-01
.... The noniterative extended Prony algorithm is used for the signal fitting and frequency estimate. Monte Carlo simulations demonstrate the advantages of the method for optimal water-fat separation and temperature estimation accuracy...
Characterization of the cardiac Na+/K+ pump by development of a comprehensive and mechanistic model.
Oka, Chiaki; Cha, Chae Young; Noma, Akinori
2010-07-07
A large amount of experimental data on the characteristics of the cardiac Na(+)/K(+) pump have been accumulated, but it remains difficult to predict the quantitative contribution of the pump in an intact cell because most measurements have been made under non-physiological conditions. To extrapolate the experimental findings to intact cells, we have developed a comprehensive Na(+)/K(+) pump model based on the thermodynamic framework (Smith and Crampin, 2004) of the Post-Albers reaction cycle combined with access channel mechanisms. The new model explains a variety of experimental results for the Na(+)/K(+) pump current (I(NaK)), including the dependency on the concentrations of Na(+) and K(+), the membrane potential and the free energy of ATP hydrolysis. The model demonstrates that both the apparent affinity and the slope of the substrate-I(NaK) relationship measured experimentally are affected by the composition of ions in the extra- and intracellular solutions, indirectly through alteration in the probability distribution of individual enzyme intermediates. By considering the voltage dependence in the Na(+)- and K(+)-binding steps, the experimental voltage-I(NaK) relationship could be reconstructed with application of experimental ionic compositions in the model, and the view of voltage-dependent K(+) binding was supported. Re-evaluation of charge movements accompanying Na(+) and K(+) translocations gave a reasonable number for the site density of the Na(+)/K(+) pump on the membrane. The new model is relevant for simulation of cellular functions under various interventions, such as depression of energy metabolism. (c) 2010 Elsevier Ltd. All rights reserved.
Sanchez, Pablo; Zorrilla, Marta; Duque, Rafael; Nieto-Reyes, Alicia
2011-01-01
Models in Software Engineering are considered as abstract representations of software systems. Models highlight relevant details for a certain purpose, whereas irrelevant ones are hidden. Models are supposed to make system comprehension easier by reducing complexity. Therefore, models should play a key role in education, since they would ease the…
National Research Council Canada - National Science Library
Steiber, Annika; Alänge, Sverker
2015-01-01
..., especially the processes through which organizational innovations are created, diffused, and sustained. There is thus a need for a more comprehensive understanding of mechanisms catalyzing organizational development...
Lorenzo Sacconi
2004-01-01
This paper is the first part of a two parts essay aimed at giving a contractarian foundation to the concept of Corporate Social Responsibility (CSR) meant as an extended model of corporate governance of the firm. I fist present the heuristics of the scientific program meant to theorizing over an institution like a system of corporate governance, which is partitioned in two domains, the justification domain and the compliance domain. Bargaining theory, reputation game and reciprocity theories,...