CSIR Research Space (South Africa)
Leenen, L
2007-12-01
Full Text Available The authors present a variant of the Weighted Maximum Satisfiability Problem (Weighted Max-SAT), which is a modeling of the Semiring Constraint Satisfaction framework. They show how to encode a Semiring Constraint Satisfaction Problem (SCSP...
Model Transformations? Transformation Models!
Bézivin, J.; Büttner, F.; Gogolla, M.; Jouault, F.; Kurtev, I.; Lindow, A.
2006-01-01
Much of the current work on model transformations seems essentially operational and executable in nature. Executable descriptions are necessary from the point of view of implementation. But from a conceptual point of view, transformations can also be viewed as descriptive models by stating only the
Directory of Open Access Journals (Sweden)
Guoqing Zhou
2016-06-01
Full Text Available This paper proposes a novel rigorous transformation model for 2D-3D registration to address the difficult problem of obtaining a sufficient number of well-distributed ground control points (GCPs in urban areas with tall buildings. The proposed model applies two types of geometric constraints, co-planarity and perpendicularity, to the conventional photogrammetric collinearity model. Both types of geometric information are directly obtained from geometric building structures, with which the geometric constraints are automatically created and combined into the conventional transformation model. A test field located in downtown Denver, Colorado, is used to evaluate the accuracy and reliability of the proposed method. The comparison analysis of the accuracy achieved by the proposed method and the conventional method is conducted. Experimental results demonstrated that: (1 the theoretical accuracy of the solved registration parameters can reach 0.47 pixels, whereas the other methods reach only 1.23 and 1.09 pixels; (2 the RMS values of 2D-3D registration achieved by the proposed model are only two pixels along the x and y directions, much smaller than the RMS values of the conventional model, which are approximately 10 pixels along the x and y directions. These results demonstrate that the proposed method is able to significantly improve the accuracy of 2D-3D registration with much fewer GCPs in urban areas with tall buildings.
Geometric constraint solving with geometric transformation
Institute of Scientific and Technical Information of China (English)
无
2001-01-01
This paper proposes two algorithms for solving geometric constraint systems. The first algorithm is for constrained systems without loops and has linear complexity. The second algorithm can solve constraint systems with loops. The latter algorithm is of quadratic complexity and is complete for constraint problems about simple polygons. The key to it is to combine the idea of graph based methods for geometric constraint solving and geometric transformations coming from rule-based methods.
Model-Driven Constraint Programming
Chenouard, Raphael; Soto, Ricardo; 10.1145/1389449.1389479
2010-01-01
Constraint programming can definitely be seen as a model-driven paradigm. The users write programs for modeling problems. These programs are mapped to executable models to calculate the solutions. This paper focuses on efficient model management (definition and transformation). From this point of view, we propose to revisit the design of constraint-programming systems. A model-driven architecture is introduced to map solving-independent constraint models to solving-dependent decision models. Several important questions are examined, such as the need for a visual highlevel modeling language, and the quality of metamodeling techniques to implement the transformations. A main result is the s-COMMA platform that efficiently implements the chain from modeling to solving constraint problems
Rewriting Constraint Models with Metamodels
Chenouard, Raphael; Soto, Ricardo
2010-01-01
An important challenge in constraint programming is to rewrite constraint models into executable programs calculat- ing the solutions. This phase of constraint processing may require translations between constraint programming lan- guages, transformations of constraint representations, model optimizations, and tuning of solving strategies. In this paper, we introduce a pivot metamodel describing the common fea- tures of constraint models including different kinds of con- straints, statements like conditionals and loops, and other first-class elements like object classes and predicates. This metamodel is general enough to cope with the constructions of many languages, from object-oriented modeling languages to logic languages, but it is independent from them. The rewriting operations manipulate metamodel instances apart from languages. As a consequence, the rewriting operations apply whatever languages are selected and they are able to manage model semantic information. A bridge is created between the metamode...
Constraint-Preserving Architecture Transformations: A Graph Rewriting Approach
Institute of Scientific and Technical Information of China (English)
YUAN Chun; CHEN Yiyun
2001-01-01
Architecture transformations are frequently performed during software design and maintenance. However this activity is not well supported at a sufficiently abstract level.In this paper, the authors characterize architecture transformations using graph rewriting rules,where architectures are represented in graph notations. Architectures are usually required to satisfy certain constraints during evolution. Therefore a way is presented to construct the sufficient and necessary condition for a transformation to preserve a constraint. The condition can be verified before the application of the transformation. Validated transformations are guaranteed not to violate corresponding constraints whenever applied.
Constraints Modeling in FRBR Data Model Using OCL
Rudić, Gordana
2011-09-01
Transformation of the conceptual FRBR data model to the class diagram in UML 2.0 notation is given. The class diagram is formed using MagicDraw CASE tool. The paper presents a class diagram for the first group of FRBR entities ie. classes (the product of intellectual or artistic endeavour). It is demonstrated how to model constraints over relationships between classes in FRBR object data model using OCL 2.0.
Constraints on the timeon model
Araki, Takeshi; Geng, C. Q.
2009-04-01
The timeon model recently proposed by Friedberg and Lee has a potential problem of flavor changing neutral currents (FCNCs) if the mass of the timeon is small. In order to avoid, we introduce a small dimensionless parameter to suppress FCNCs. Even in this case, we find that the timeon mass must be larger than 151 GeV to satisfy all the constraints from processes involving FCNCs in the quark sectors. We also extend the timeon model to the lepton sector and examine the leptonic processes.
Scalable Models Using Model Transformation
2008-07-13
and the following companies: Agilent, Bosch, HSBC , Lockheed-Martin, National Instruments, and Toyota. Scalable Models Using Model Transformation...parametrization, and workflow automation. (AFRL), the State of California Micro Program, and the following companies: Agi- lent, Bosch, HSBC , Lockheed
Minimal Model Semantics for Sorted Constraint Representation
Institute of Scientific and Technical Information of China (English)
廖乐健; 史忠植
1995-01-01
Sorted constraint representation is a very useful representation in AI which combines class hierarchies and constraint networks.For such sorted constraint representation,a problem is how to generalize the idea of default inheritance to constraint network,where the attributes in a class or between different classes interact with each other via the network.To give a formal account for the defeasible reasoning in such representation,a general sorted constraint logic is proposed,and a minimal-model semantics for the logic is presented.
Gato-Rivera, Beatriz
1993-01-01
We use the Kontsevich-Miwa transform to relate the different pictures describing matter coupled to topological gravity in two dimensions: topological theories, Virasoro constraints on integrable hierarchies, and a DDK-type formalism. With the help of the Kontsevich-Miwa transform, we solve the Virasoro constraints on the KP hierarchy in terms of minimal models dressed with a (free) Liouville-like scalar. The dressing prescription originates in a topological (twisted N=2) theory. The Virasoro constraints are thus related to essentially the N=2 null state decoupling equations. The N=2 generators are constructed out of matter, the `Liouville' scalar, and $c=-2$ ghosts. By a `dual' construction involving the reparametrization $c=-26$ ghosts, the DDK dressing prescription is reproduced from the N=2 symmetry. As a by-product we thus observe that there are two ways to dress arbitrary $d\\leq1$ or $d\\geq25$ matter theory, that allow its embedding into a topological theory. By th e Kontsevich-Miwa transform, which intr...
Constraint theory multidimensional mathematical model management
Friedman, George J
2017-01-01
Packed with new material and research, this second edition of George Friedman’s bestselling Constraint Theory remains an invaluable reference for all engineers, mathematicians, and managers concerned with modeling. As in the first edition, this text analyzes the way Constraint Theory employs bipartite graphs and presents the process of locating the “kernel of constraint” trillions of times faster than brute-force approaches, determining model consistency and computational allowability. Unique in its abundance of topological pictures of the material, this book balances left- and right-brain perceptions to provide a thorough explanation of multidimensional mathematical models. Much of the extended material in this new edition also comes from Phan Phan’s PhD dissertation in 2011, titled “Expanding Constraint Theory to Determine Well-Posedness of Large Mathematical Models.” Praise for the first edition: "Dr. George Friedman is indisputably the father of the very powerful methods of constraint theory...
Expressing Model Constraints Visually with VMQL
DEFF Research Database (Denmark)
Störrle, Harald
2011-01-01
OCL is the de facto standard language for expressing constraints and queries on UML models. However, OCL expressions are very difficult to create, understand, and maintain, even with the sophisticated tool support now available. In this paper, we propose to use the Visual Model Query Language (VMQL......) for specifying constraints on UML models. We examine VMQL's usability by controlled experiments and its expressiveness by a representative sample. We conclude that VMQL is less expressive than OCL, although expressive enough for most of the constraints in the sample. In terms of usability, however, VMQL...... is superior to OCL, although the experimental evidence we present here is not as compelling as the one we presented when comparing VMQL and OCL on model querying....
A Transformational Approach for Proving Properties of the CHR Constraint Store
Pilozzi, Paolo; Schrijvers, Tom; Bruynooghe, Maurice
Proving termination of, or generating efficient control for Constraint Handling Rules (CHR) programs requires information about the kinds of constraints that can show up in the CHR constraint store. In contrast to Logic Programming (LP), there are not many tools available for deriving such information for CHR. Hence, instead of building analyses for CHR from scratch, we define a transformation from CHR to Prolog and reuse existing analysis tools for Prolog.
MCC: A Model Transformation Environment
Kleppe, A.G.
2006-01-01
In the model driven software development process, software is built by constructing one or more models and transforming these into other models. In turn these output models may be transformed into another set of models until finally the output consists of program code that can be executed. Ultimatel
Fourier-positivity constraints on QCD dipole models
Directory of Open Access Journals (Sweden)
Bertrand G. Giraud
2016-09-01
Full Text Available Fourier-positivity (F-positivity, i.e. the mathematical property that a function has a positive Fourier transform, can be used as a constraint on the parametrization of QCD dipole-target cross-sections or Wilson line correlators in transverse position space r. They are Bessel transforms of positive transverse momentum dependent gluon distributions. Using mathematical F-positivity constraints on the limit r→0 behavior of the dipole amplitudes, we identify the common origin of the violation of F-positivity for various, however phenomenologically convenient, dipole models. It is due to the behavior r2+ϵ, ϵ>0 softer, even slightly, than color transparency. F-positivity seems thus to conflict with the present dipole formalism when it includes a QCD running coupling constant α(r.
Constraints on galactic wind models
Meiksin, Avery
2016-09-01
Observational implications are derived for two standard models of supernovae-driven galactic winds: a freely expanding steady-state wind and a wind sourced by a self-similarly expanding superbubble including thermal heat conduction. It is shown that, for the steady-state wind, matching the measured correlation between the soft X-ray luminosity and star formation rate of starburst galaxies is equivalent to producing a scaled wind mass-loading factor relative to the star formation rate of 0.5-3, in agreement with the amount inferred from metal absorption line measurements. The match requires the asymptotic wind velocity v∞ to scale with the star formation rate dot{M}_{ast } (in M⊙ yr-1) approximately as v_∞ ≃ (700-1000) {{km s^{-1}}} {dot{M}_{ast }}^{1/6}. The implied mass injection rate is close to the amount naturally provided by thermal evaporation from the wall of a superbubble in a galactic disc, suggesting that thermal evaporation may be a major source of mass loading. The predicted mass-loading factors from thermal evaporation within the galactic disc alone, however, are somewhat smaller, 0.2-2, so that a further contribution from cloud ablation or evaporation within the wind may be required. Both models may account for the 1.4 GHz luminosity of unresolved radio sources within starburst galaxies for plausible parameters describing the distribution of relativistic electrons. Further observational tests to distinguish the models are suggested.
Enceladus: UVIS Constraints and Modeling
Hansen, Candice; Esposito, Larry W.; Shemansky, Donald; Stewart, Ian; Hendrix, Amanda
The Cassini Ultraviolet Imaging Spectrograph (UVIS) will observe an occultation of the sun by Enceladus' water vapor plume on May 18, 2010. UVIS will use its extreme ultraviolet (EUV) channel for this new observation, to detect absorptions in the wavelength range 55 to 110 nm. Molecular nitrogen and carbon dioxide gas have absorptions in this range. The N2 b(3,0) line is at 97.2 nm, extinguishing the solar H Lyman gamma emission. Cassini's Ion and Neutral Mass Spectrometer (INMS) has detected a species with an atomic mass of 28 amu, at a 4.4 The identification of N2 is important for models of the interior and the source of the plume, as its presence would be consistent with liquid water in Enceladus' interior. N2 is not believed to be primordial in Saturn's system based on the lack of argon in Titan's N2 atmosphere [3] so its presence in Enceladus' plume implies thermal decomposition of NH3 [4] at temperatures above the melting point of water ice. Quantification of the amount of N2 in the plume will enable improved models of the possible aqueous geochemistry taking place in the interior [5]. UVIS will be able to detect N2 at a mixing ratio as low as 0.005 in the water vapor plume. If there is 4.4 Results of the two stellar occultations observed by UVIS in 2005 and 2007 in the far ultraviolet (FUV) channel gave the column density of water vapor in the plume, structure of the vapor jets, and allowed us to derive the flux of water into Saturn's system which ultimately supplies the neutral atomic oxygen that profoundly influences the processes in the magnetosphere [6, 7]. The new opportunity afforded by this solar occultation will be used to further model the structure and dynamics of the plume, allowing us to probe the source of the enigmatic activity below Enceladus' surface. References: 1. Waite, J. H. et al, Science 311:1419-1422 (2006). 2. Waite, J. H. et al, Nature 460:487-490 (2009). 3. Niemann, H. B. et al, Nature 438:779-784 (2005). 4. Matson, D. L. et al
Constraints on galactic wind models
Meiksin, Avery
2016-01-01
Observational implications are derived for two standard models of supernovae-driven galactic winds: a freely expanding steady-state wind and a wind sourced by a self-similarly expanding superbubble including thermal heat conduction. It is shown that, for the steady-state wind, matching the measured correlation between the soft x-ray luminosity and star formation rate of starburst galaxies is equivalent to producing a scaled wind mass-loading factor relative to the star-formation rate of 0.5 - 3, in agreement with the amount inferred from metal absorption line measurements. The match requires the asymptotic wind velocity v_inf to scale with the star formation rate SFR (in solar masses per year) approximately as v_inf ~ (700 - 1000) km/s SFR^{1/6}. The corresponding mass injection rate is close to the amount naturally provided by thermal evaporation from the wall of a superbubble in a galactic disc, suggesting thermal evaporation may be a major source of mass-loading. The predicted mass-loading factors from the...
Hierarchical Geometric Constraint Model for Parametric Feature Based Modeling
Institute of Scientific and Technical Information of China (English)
高曙明; 彭群生
1997-01-01
A new geometric constraint model is described,which is hierarchical and suitable for parametric feature based modeling.In this model,different levels of geometric information are repesented to support various stages of a design process.An efficient approach to parametric feature based modeling is also presented,adopting the high level geometric constraint model.The low level geometric model such as B-reps can be derived automatically from the hig level geometric constraint model,enabling designers to perform their task of detailed design.
Institute of Scientific and Technical Information of China (English)
无
2009-01-01
This paper analyzes the constraint factors of forestry scientific and technological achievements transformation and explores the countermeasures and measures to promote the transformation. It points out that to achieve maximum return from investment funds in forestry research, it shall improve the transformation of scientific and technological achievements, enhance independent innovation capability, and greatly enhance the supply capacity of scientific and technological achievements, so as to provide endles...
A Constraint Model for Constrained Hidden Markov Models
DEFF Research Database (Denmark)
Christiansen, Henning; Have, Christian Theil; Lassen, Ole Torp
2009-01-01
A Hidden Markov Model (HMM) is a common statistical model which is widely used for analysis of biological sequence data and other sequential phenomena. In the present paper we extend HMMs with constraints and show how the familiar Viterbi algorithm can be generalized, based on constraint solving...
INFORMATION MODEL OF SOCIAL TRANSFORMATIONS
Directory of Open Access Journals (Sweden)
Мария Васильевна Комова
2013-09-01
Full Text Available The social transformation is considered as a process of qualitative changes of the society, creating a new level of organization in all areas of life, in different social formations, societies of different types of development. The purpose of the study is to create a universal model for studying social transformations based on their understanding as the consequence of the information exchange processes in the society. After defining the conceptual model of the study, the author uses the following methods: the descriptive method, analysis, synthesis, comparison.Information, objectively existing in all elements and systems of the material world, is an integral attribute of the society transformation as well. The information model of social transformations is based on the definition of the society transformation as the change in the information that functions in the society’s information space. The study of social transformations is the study of information flows circulating in the society and being characterized by different spatial, temporal, and structural states. Social transformations are a highly integrated system of social processes and phenomena, the nature, course and consequences of which are affected by the factors representing the whole complex of material objects. The integrated information model of social transformations foresees the interaction of the following components: social memory, information space, and the social ideal. To determine the dynamics and intensity of social transformations the author uses the notions of "information threshold of social transformations" and "information pressure".Thus, the universal nature of information leads to considering social transformations as a system of information exchange processes. Social transformations can be extended to any episteme actualized by social needs. The establishment of an information threshold allows to simulate the course of social development, to predict the
A Hybrid Model Predictive Control for Handling Infeasibility and Constraint Prioritization
Institute of Scientific and Technical Information of China (English)
王宇红; 黄德先; 金以慧
2005-01-01
A hybrid approach using MLD (mixed logical dynamical) framework to handle infeasibility and constraint prioritization issues in MPC (model predictive control) based on input-output model is introduced. By expressing constraint priorities as propositional logics and by transforming the propositional logics into inequalities,the infeasibility and constraint prioritization issues are solved in the MPC. Constraints with higher priorities are met first, and then these with lower priorities are satisfied as much as possible. This new approach is illustrated in the control of a heavy oil fractionator-Shell column. The overall control performance has been significantly improved through the infeasibility and control priorities handling.
Observational constraints on the LLTB model
Marra, Valerio
2010-01-01
We directly compare the concordance LCDM model to the inhomogeneous matter-only alternative represented by LTB void models. To achieve a "democratic" confrontation we explore LLTB models with non-vanishing cosmological constant and perform a global likelihood analysis in the parameter space of cosmological constant and void radius. In our analysis we carefully consider SNe, Hubble constant, CMB and BAO measurements, marginalizing over the age of the universe and the background curvature. We find that the LCDM model is not the only possibility compatible with the observations, and that a matter-only void model is a viable alternative to the concordance model only if the BAO constraints are relaxed. Moreover, we will show that the areas of the parameter space which give a good fit to the observations are always disconnected with the result that a small local void does not significantly affect the parameter extraction for LCDM models.
A Complete and Terminating Execution Model for Constraint Handling Rules
Betz, Hariolf; Frühwirth, Thom; 10.1017/S147106841000030X
2010-01-01
We observe that the various formulations of the operational semantics of Constraint Handling Rules proposed over the years fall into a spectrum ranging from the analytical to the pragmatic. While existing analytical formulations facilitate program analysis and formal proofs of program properties, they cannot be implemented as is. We propose a novel operational semantics, which has a strong analytical foundation, while featuring a terminating execution model. We prove its soundness and completeness with respect to existing analytical formulations and we provide an implementation in the form of a source-to-source transformation to CHR with rule priorities.
Implementing network constraints in the EMPS model
Energy Technology Data Exchange (ETDEWEB)
Helseth, Arild; Warland, Geir; Mo, Birger; Fosso, Olav B.
2010-02-15
This report concerns the coupling of detailed market and network models for long-term hydro-thermal scheduling. Currently, the EPF model (Samlast) is the only tool available for this task for actors in the Nordic market. A new prototype for solving the coupled market and network problem has been developed. The prototype is based on the EMPS model (Samkjoeringsmodellen). Results from the market model are distributed to a detailed network model, where a DC load flow detects if there are overloads on monitored lines or intersections. In case of overloads, network constraints are generated and added to the market problem. Theoretical and implementation details for the new prototype are elaborated in this report. The performance of the prototype is tested against the EPF model on a 20-area Nordic dataset. (Author)
Institute of Scientific and Technical Information of China (English)
WANG Qingfei; DENG Jun; HUANG Dinghua; YANG Liqiang; GAO Bangfei; XU Hao; JIANG Shaoqing
2006-01-01
During the Paleozoic, the Ordos area in the western North China Plate was located at the intersecting position of microplates and controlled by their interaction. The structural framework in the Ordos area, which underwent transformations in the Ordovician, the Carboniferous and the Permian respectively, was dominated by the alternation of uplift and depression. The transformations of structural framework are utilized as the clues to investigate the microplates' interacting type and its response in the Ordos area. According to the regional structural evolution, the Ordos area is simplified into an isopachous, isotropic and elastic shell model, and under proposed various boundary conditions,three series of numerical simulations corresponding to the three structural transformations are carried out to determine the detailed tectonic constraints. Numerical simulations reveal that the structure of the uplift and depression, which is similar to the actual pattern, develops only under one special boundary condition in each of the three series, indicating that the structural framework responds to the unique tectonic background. The simulation results show that in the Early Paleozoic, the L-shaped paleouplift formed nearby the southwestern corner of the Ordos area because the intensity of the compressions in the southern and western boundaries resulting from the ocean-continent collisions was similar. In the Late Paleozoic, it evolved into continent-continent (or arc-continent) interaction in the southern and northern boundaries; in the preliminary stage of the interaction, since the interface between the North China Plate and the plates on the south and north was narrow, the relative acting force was little and the regional western boundary immobile, and the structural framework in the basin was characterized by the N-S trending slender-waist-shaped uplift; as the interface between the plates expanded gradually, the extrusive force in the southern and northern boundaries
Placing Observational Constraints on Massive Star Models
Rosenfield, Philip
2011-10-01
The lives and deaths of massive stars are intricately linked to the evolution of galaxies. Yet, despite their integral importance to understanding galaxy evolution, models of massive stars are inconsistent with observations. These uncertainties can be traced to limited observational constraints available for improving massive star models. A sensitive test of the underlying physics of massive stars, e.g., convection, rotation, and mass loss is to measure the ratio of blue core helium burning stars {BHeB} to red core helium burning stars {RHeB}, 5-20Msun stars in the stage evolution immediately following the main sequence. Even the most sophisticated models cannot accurately predict the observed ratio over a range of metallicities, suggesting an insufficient understanding of the underlying physics. However, observational measurements of this ratio over a wide range of environments would provide substantial constraints on the physical parameters governing the evolution of all stars >5 Msun.We propose to place stringent observational constraints on the physics of massive star evolution by uniformly measuring the B/R HeB ratio in a wide range of galaxies. The HST archive contains high quality optical imaging of resolved stellar populations of dozens of nearby galaxies. From the ANGST program, we identified 38 galaxies, spanning 2 dex in metallicity that have significant BHeB and RHeB populations. Using this sample, we will empirically characterize the colors of the BHeB and RHeB sequences as a function of luminosity and metallicity, measure the B/R ratio, and constrain the lifetimes of the BHeB and RHeBs in the Padova stellar evolution models and the Cambridge STARS code.
Specifying Usage Control ModelWith Object Constraint Language
Directory of Open Access Journals (Sweden)
Min Li
2013-02-01
Full Text Available The recent usage control model (UCON is a foundation for next-generation access control models with distinguishing properties of decision continuity and attribute mutability. Constraints in UCON are one of the most important components that have involved in the principle motivations of usage analysis and design. The importance of constraints associated with authorizations, obligations, and conditions in UCON has been recognized but modeling these constraints has not been received much attention. In this paper we use a de facto constraints specification language in software engineering to analyze the constraints in UCON model. We show how to represent constraints with object constraint language (OCL and give out a formalized specification of UCON model which is built from basic constraints, such as authorization predicates, obligation actions and condition requirements. Further, we show the flexibility and expressive capability of this specified UCON model with extensive examples.
Finite BRST-BFV transformations for dynamical systems with second-class constraints
Batalin, Igor A.; Lavrov, Peter M.; Tyutin, Igor V.
2015-06-01
We study finite field-dependent BRST-BFV transformations for dynamical systems with first- and second-class constraints within the generalized Hamiltonian formalism. We find explicitly their Jacobians and the form of a solution to the compensation equation necessary for generating an arbitrary finite change of gauge-fixing functionals in the path integral.
Finite BRST-BFV transformations for dynamical systems with second-class constraints
Batalin, Igor A; Tyutin, Igor V
2015-01-01
We study finite field dependent BRST-BFV transformations for dynamical systems with first- and second-class constraints within the generalized Hamiltonian formalism. We find explicitly their Jacobians and the form of a solution to the compensation equation necessary for generating an arbitrary finite change of gauge-fixing functionals in the path integral.
Infrared Constraints on AGN Tori Models
Hatziminaoglou, E; Pérez-Fournon, I; Franceschini, A; Hernan-Caballero, A; Afonso-Luis, A; Lonsdale, C; Fang, F; Oliver, S; Rowan-Robinson, M; Shupe, D; Smith, H; Surace, J; Gonzales-Solares, E
2006-01-01
This work focuses on the properties of dusty tori in active galactic nuclei (AGN) derived from the comparison of SDSS type 1 quasars with mid-Infrared (MIR) counterparts and a new, detailed torus model. The infrared data were taken by the Spitzer Wide-area InfraRed Extragalactic (SWIRE) Survey. Basic model parameters are constraint, such as the density law of the graphite and silicate grains, the torus size and its opening angle. A whole variety of optical depths is supported. The favoured models are those with decreasing density with distance from the centre, while there is no clear tendency as to the covering factor, ie small, medium and large covering factors are almost equally distributed. Based on the models that better describe the observed SEDs, properties such as the accretion luminosity, the mass of dust, the inner to outer radius ratio and the hydrogen column density are computed.
Observation Constraints on the Simplified GCG Model
Institute of Scientific and Technical Information of China (English)
DONG Su-Mei; WU Pu-Xun
2007-01-01
A simplified version of generalized Chaplygin gas (GCG) as a dark energy model is studied. By using the latest 162 ESSENCE type la supernovae (Sne la) data, 30 high redshift Sne la data, the baryonk acoustic oscillation peak from SDSS and the CMB data from WMAP3, a strong constraint on this simplified GCG model is obtained. At the 95.4% confidence level we obtain 0.21 ≤ Ωm ≤ 0.31 and 0.994 ≤ a ≤ 1.0 with the best fit fim = 0.25 and a = 1. This best fit scenario corresponds to an accelerating universe with qo ～_0.65 and z ～- 0.81 (a redshift of cosmic phase transition from deceleration to acceleration).
Directory of Open Access Journals (Sweden)
Paweł Sitek
2016-01-01
Full Text Available This paper presents a hybrid method for modeling and solving supply chain optimization problems with soft, hard, and logical constraints. Ability to implement soft and logical constraints is a very important functionality for supply chain optimization models. Such constraints are particularly useful for modeling problems resulting from commercial agreements, contracts, competition, technology, safety, and environmental conditions. Two programming and solving environments, mathematical programming (MP and constraint logic programming (CLP, were combined in the hybrid method. This integration, hybridization, and the adequate multidimensional transformation of the problem (as a presolving method helped to substantially reduce the search space of combinatorial models for supply chain optimization problems. The operation research MP and declarative CLP, where constraints are modeled in different ways and different solving procedures are implemented, were linked together to use the strengths of both. This approach is particularly important for the decision and combinatorial optimization models with the objective function and constraints, there are many decision variables, and these are summed (common in manufacturing, supply chain management, project management, and logistic problems. The ECLiPSe system with Eplex library was proposed to implement a hybrid method. Additionally, the proposed hybrid transformed model is compared with the MILP-Mixed Integer Linear Programming model on the same data instances. For illustrative models, its use allowed finding optimal solutions eight to one hundred times faster and reducing the size of the combinatorial problem to a significant extent.
Flavor Constraints on Split Fermion Models
Energy Technology Data Exchange (ETDEWEB)
Lillie, Ben
2003-06-26
We examine the contributions to rare processes that arise in models where the Standard Model fermions are localized at distinct points in compact extra dimensions. Tree-level flavor changing neutral current interactions for the Kaluza-Klein (KK) gauge field excitations are induced in such models, and hence strong constraints are thought to exist on the size of the additional dimensions. We find a general parameterization of the model which does not depend on any specific fermion geography and show that typical values of the parameters can reproduce the fermion hierarchy pattern. Using this parameterization, we reexamine the contributions to neutral meson mixing, rare meson decays, and single top-quark production in e{sup +}e{sup -} collisions. We find that is it possible to evade the stringent bounds for natural regions of the parameters, while retaining finite separations between the fermion fields and without introducing a new hierarchy. The resulting limits on the size of the compact dimension can be as low as TeV{sup -1}.
Flavor Constraints on Split Fermion Models
Lillie, Benjamin Huntington; Lillie, Ben; Hewett, JoAnne
2003-01-01
We examine the contributions to rare processes that arise in models where the Standard Model fermions are localized at distinct points in compact extra dimensions. Tree-level flavor changing neutral current interactions for the Kaluza-Klein (KK) gauge field excitations are induced in such models, and hence strong constraints are thought to exist on the size of the additional dimensions. We find a general parameterization of the model which does not depend on any specific fermion geography and show that typical values of the parameters can reproduce the fermion hierarchy pattern. Using this parameterization, we reexamine the contributions to neutral meson mixing, rare meson decays, and single top-quark production in $e^+e^-$ collisions. We find that is it possible to evade the stringent bounds for natural regions of the parameters, while retaining finite separations between the fermion fields and without introducing a new hierarchy. The resulting limits on the size of the compact dimension can be as low as TeV...
Stability Constraints for Robust Model Predictive Control
Directory of Open Access Journals (Sweden)
Amanda G. S. Ottoni
2015-01-01
Full Text Available This paper proposes an approach for the robust stabilization of systems controlled by MPC strategies. Uncertain SISO linear systems with box-bounded parametric uncertainties are considered. The proposed approach delivers some constraints on the control inputs which impose sufficient conditions for the convergence of the system output. These stability constraints can be included in the set of constraints dealt with by existing MPC design strategies, in this way leading to the “robustification” of the MPC.
A model for strategy in constraint solving
Wijk, J.J. van
1997-01-01
The use of constraints for the definition of graphical user interfaces has been recognized as a great concept. However, often many valuations of the variables will satisfy the constraints, and which particular valuation matches best with the expectation of the user cannot be decided without further
Integrable Bogoliubov Transform and Integrable Model
Institute of Scientific and Technical Information of China (English)
王宁
2003-01-01
By defining Bogoliubov transform as a function of parameters, the integrability of the Bogoliubov transform in parameter space is investigated. It is shown that integrable Bogoliubov transform is closely related to the known integrable model. The relation between the integrable Bogoliubov transform and geometric phase of vacuum induced by the Bogoliubov transform is also discussed.
Laboratory constraints on models of earthquake recurrence
Beeler, Nicholas M.; Tullis, Terry; Junger, Jenni; Kilgore, Brian D.; Goldsby, David L.
2014-01-01
In this study, rock friction ‘stick-slip’ experiments are used to develop constraints on models of earthquake recurrence. Constant-rate loading of bare rock surfaces in high quality experiments produces stick-slip recurrence that is periodic at least to second order. When the loading rate is varied, recurrence is approximately inversely proportional to loading rate. These laboratory events initiate due to a slip rate-dependent process that also determines the size of the stress drop [Dieterich, 1979; Ruina, 1983] and as a consequence, stress drop varies weakly but systematically with loading rate [e.g., Gu and Wong, 1991; Karner and Marone, 2000; McLaskey et al., 2012]. This is especially evident in experiments where the loading rate is changed by orders of magnitude, as is thought to be the loading condition of naturally occurring, small repeating earthquakes driven by afterslip, or low-frequency earthquakes loaded by episodic slip. As follows from the previous studies referred to above, experimentally observed stress drops are well described by a logarithmic dependence on recurrence interval that can be cast as a non-linear slip-predictable model. The fault’s rate dependence of strength is the key physical parameter. Additionally, even at constant loading rate the most reproducible laboratory recurrence is not exactly periodic, unlike existing friction recurrence models. We present example laboratory catalogs that document the variance and show that in large catalogs, even at constant loading rate, stress drop and recurrence co-vary systematically. The origin of this covariance is largely consistent with variability of the dependence of fault strength on slip rate. Laboratory catalogs show aspects of both slip and time predictability and successive stress drops are strongly correlated indicating a ‘memory’ of prior slip history that extends over at least one recurrence cycle.
Transparent Model Transformation: Turning Your Favourite Model Editor into a Transformation Tool
DEFF Research Database (Denmark)
Acretoaie, Vlad; Störrle, Harald; Strüber, Daniel
2015-01-01
Current model transformation languages are supported by dedicated editors, often closely coupled to a single execution engine. We introduce Transparent Model Transformation, a paradigm enabling modelers to specify transformations using a familiar tool: their model editor. We also present VMTL......, the first transformation language implementing the principles of Transparent Model Transformation: syntax, environment, and execution transparency. VMTL works by weaving a transformation aspect into its host modeling language. We show how our implementation of VMTL turns any model editor into a flexible...
Register Allocation By Model Transformer Semantics
Wang, Yin
2012-01-01
Register allocation has long been formulated as a graph coloring problem, coloring the conflict graph with physical registers. Such a formulation does not fully capture the goal of the allocation, which is to minimize the traffic between registers and memory. Linear scan has been proposed as an alternative to graph coloring, but in essence, it can be viewed as a greedy algorithm for graph coloring: coloring the vertices not in the order of their degrees, but in the order of their occurence in the program. Thus it suffers from almost the same constraints as graph coloring. In this article, I propose a new method of register allocation based on the ideas of model transformer semantics (MTS) and static cache replacement (SCR). Model transformer semantics captures the semantics of registers and the stack. Static cache replacement relaxes the assumptions made by graph coloring and linear scan, aiming directly at reducing register-memory traffic. The method explores a much larger solution space than that of graph c...
Pitts, J. Brian
2014-12-01
In Dirac-Bergmann constrained dynamics, a first-class constraint typically does not alone generate a gauge transformation. By direct calculation it is found that each first-class constraint in Maxwell's theory generates a change in the electric field E → by an arbitrary gradient, spoiling Gauss's law. The secondary first-class constraint pi,i = 0 still holds, but being a function of derivatives of momenta (mere auxiliary fields), it is not directly about the observable electric field (a function of derivatives of Aμ), which couples to charge. Only a special combination of the two first-class constraints, the Anderson-Bergmann-Castellani gauge generator G, leaves E → unchanged. Likewise only that combination leaves the canonical action invariant-an argument independent of observables. If one uses a first-class constraint to generate instead a canonical transformation, one partly strips the canonical coordinates of physical meaning as electromagnetic potentials, vindicating the Anderson-Bergmann Lagrangian orientation of interesting canonical transformations. The need to keep gauge-invariant the relation q ˙ -δH/δp = -Ei -pi = 0 supports using the gauge generator and primary Hamiltonian rather than the separate first-class constraints and the extended Hamiltonian. Partly paralleling Pons's criticism, it is shown that Dirac's proof that a first-class primary constraint generates a gauge transformation, by comparing evolutions from identical initial data, cancels out and hence fails to detect the alterations made to the initial state. It also neglects the arbitrary coordinates multiplying the secondary constraints inside the canonical Hamiltonian. Thus the gauge-generating property has been ascribed to the primaries alone, not the primary-secondary team G. Hence the Dirac conjecture about secondary first-class constraints as generating gauge transformations rests upon a false presupposition about primary first-class constraints. Clarity about Hamiltonian
Model Validation in Ontology Based Transformations
Directory of Open Access Journals (Sweden)
Jesús M. Almendros-Jiménez
2012-10-01
Full Text Available Model Driven Engineering (MDE is an emerging approach of software engineering. MDE emphasizes the construction of models from which the implementation should be derived by applying model transformations. The Ontology Definition Meta-model (ODM has been proposed as a profile for UML models of the Web Ontology Language (OWL. In this context, transformations of UML models can be mapped into ODM/OWL transformations. On the other hand, model validation is a crucial task in model transformation. Meta-modeling permits to give a syntactic structure to source and target models. However, semantic requirements have to be imposed on source and target models. A given transformation will be sound when source and target models fulfill the syntactic and semantic requirements. In this paper, we present an approach for model validation in ODM based transformations. Adopting a logic programming based transformational approach we will show how it is possible to transform and validate models. Properties to be validated range from structural and semantic requirements of models (pre and post conditions to properties of the transformation (invariants. The approach has been applied to a well-known example of model transformation: the Entity-Relationship (ER to Relational Model (RM transformation.
Finding Deadlocks of Event-B Models by Constraint Solving
DEFF Research Database (Denmark)
Hallerstede, Stefan; Leuschel, Michael
we propose a constraint-based approach to nding deadlocks employing the ProB constraint solver to nd values for the constants and variables of formal models that describe a deadlocking state. We discuss the principles of the technique implemented in ProB's Prolog kernel and present some results...
Managing Green Business Model Transformations
Sommer, Axel
2012-01-01
Environmental sustainability creates both tremendous business opportunities and formidable threats to established companies across virtually all industry sectors. Yet many companies tackle the issue in a superficial or passive way through increased environmental reporting, the use of “greenspeak” in their corporate communication activities or isolated efforts to create green products or reduce pollution. In contrast, there are a small but increasing number of firms that employ a holistic approach to sustainability and consider fundamental changes to their existing business models. By ignoring the opportunities of Green Business Model Transformations, companies exclude themselves from a large variety of potential means to create economic value. In addition to ordinary product and process innovations, they can change “the rules of the game” within an industry towards environmental sustainability. This can facilitate the commercialisation of new green products that would not be competitive otherwise targ...
Energy Technology Data Exchange (ETDEWEB)
Pitts, J. Brian, E-mail: jbp25@cam.ac.uk
2014-12-15
In Dirac–Bergmann constrained dynamics, a first-class constraint typically does not alone generate a gauge transformation. By direct calculation it is found that each first-class constraint in Maxwell’s theory generates a change in the electric field E{sup →} by an arbitrary gradient, spoiling Gauss’s law. The secondary first-class constraint p{sup i},{sub i}=0 still holds, but being a function of derivatives of momenta (mere auxiliary fields), it is not directly about the observable electric field (a function of derivatives of A{sub μ}), which couples to charge. Only a special combination of the two first-class constraints, the Anderson–Bergmann–Castellani gauge generator G, leaves E{sup →} unchanged. Likewise only that combination leaves the canonical action invariant—an argument independent of observables. If one uses a first-class constraint to generate instead a canonical transformation, one partly strips the canonical coordinates of physical meaning as electromagnetic potentials, vindicating the Anderson–Bergmann Lagrangian orientation of interesting canonical transformations. The need to keep gauge-invariant the relation q-dot −(δH)/(δp) =−E{sub i}−p{sup i}=0 supports using the gauge generator and primary Hamiltonian rather than the separate first-class constraints and the extended Hamiltonian. Partly paralleling Pons’s criticism, it is shown that Dirac’s proof that a first-class primary constraint generates a gauge transformation, by comparing evolutions from identical initial data, cancels out and hence fails to detect the alterations made to the initial state. It also neglects the arbitrary coordinates multiplying the secondary constraints inside the canonical Hamiltonian. Thus the gauge-generating property has been ascribed to the primaries alone, not the primary–secondary team G. Hence the Dirac conjecture about secondary first-class constraints as generating gauge transformations rests upon a false presupposition about
Statistical and Energetic Constraints in Population Synthesis Models
Buzzoni, A
1998-01-01
Physical and numerical constraints in building up self-consistent population synthesis models are briefly analysed discussing their application to most of the current synthesis codes widely adopted in Galactic and extragalactic studies.
Wu, Guocan; Zheng, Xiaogu; Dan, Bo
2016-04-01
The shallow soil moisture observations are assimilated into Common Land Model (CoLM) to estimate the soil moisture in different layers. The forecast error is inflated to improve the analysis state accuracy and the water balance constraint is adopted to reduce the water budget residual in the assimilation procedure. The experiment results illustrate that the adaptive forecast error inflation can reduce the analysis error, while the proper inflation layer can be selected based on the -2log-likelihood function of the innovation statistic. The water balance constraint can result in reducing water budget residual substantially, at a low cost of assimilation accuracy loss. The assimilation scheme can be potentially applied to assimilate the remote sensing data.
Observational constraints on inflation models with nonminimal scalar field
Noh, H
2001-01-01
We present the power spectra of the scalar- and tensor-type structures generated in an inflation model based on the nonminimally coupled scalar field with a self coupling. By comparing the contributions of these structures to the anisotropy of the cosmic microwave background radiation with the four year COBE DMR data we derive strong constraints on model parameters and the inflation model.
Genetic spectrum assignment model with constraints in cognitive radio networks
Directory of Open Access Journals (Sweden)
Fang Ye
2011-06-01
Full Text Available The interference constraints of genetic spectrum assignment model in cognitive radio networks are analyzed in this paper. An improved genetic spectrum assignment model is proposed. The population of genetic algorithm is divided into two sets, the feasible spectrum assignment strategies and the randomly updated spectrum assignment strategies. The penalty function is added to the utility function to achieve the spectrum assignment strategy that satisfies the interference constraints and has better fitness. The proposed method is applicable in both the genetic spectrum assignment model and the quantum genetic spectrum assignment mode. It can ensure the randomness of partial chromosomes in the population to some extent, and reduce the computational complexity caused by the constraints-free procedure after the update of population. Simulation results show that the proposed method can achieve better performance than the conventional genetic spectrum assignment model and quantum genetic spectrum assignment model
Thermal Constraints on the Rheology of Segmented Oceanic Transform Fault Systems
Wolfson-Schwehr, M. L.; Boettcher, M. S.; Behn, M. D.
2012-12-01
Mid-ocean ridge transform fault (RTF) systems may be comprised of two or more fault segments that are physically offset by an extensional basin or intra-transform spreading center. These intra-transform offsets affect the thermal structure underlying the transform fault and may act as barriers to rupture propagation. The seismogenic zone of RTFs is thermally controlled and limited by the 600°C isotherm, as evidenced by earthquake hypocentral depths and laboratory friction experiments. Observations from a recent ocean bottom seismic study found that RTF earthquakes rarely occur above ~2 km depth. These findings suggest that the seismogenic zone on RTFs likely extends from ~2 km to the 600°C isotherm. Here we utilize finite element analysis to model the thermal structure of a RTF system comprised of two transform fault segments separated by an extensional offset. The mantle is assumed to have a visco-plastic rheology to simulate brittle failure at temperatures bounded by areas of increased microseismicity, which act as barriers to large rupture propagation. Previously, we used well-located earthquakes recorded on a NOAA hydrophone array together with a relative relocation technique to determine the absolute positions for the five rupture patches on Discovery, which host 5.4 ≤ Mw ≤ 6.0 earthquakes. In this study, we combine absolute locations of the largest earthquakes, our detailed analysis of the fault trace of Discovery, and our thermal modeling results to assess how intra-transform offsets on Discovery affect the subsurface thermal structure. Along the 6 km intra-transform spreading center we find the 600°C isotherm is shallower than 2 km, suggesting that the thermal structure of this offset creates a rupture barrier between the adjoining fault segments. By contrast, intra-transform offsets surface trace of each segment only minimally affect the depth of the 600°C isotherm, resulting in a continuous seismogenic zone between the fault segments. This
A Data Flow Behavior Constraints Model for Branch Decisionmaking Variables
Directory of Open Access Journals (Sweden)
Lu Yan
2012-06-01
Full Text Available In order to detect the attacks to decision-making variable, this paper presents a data flow behavior constraint model for branch decision-making variables. Our model is expanded from the common control flow model, itemphasizes on the analysis and verification about the data flow for decision-making variables, so that to ensure the branch statement can execute correctly and can also detect the attack to branch decision-making variableeasily. The constraints of our model include the collection of variables, the statements that the decision-making variables are dependent on and the data flow constraint with the use-def relation of these variables. Our experimental results indicate that it is effective in detecting the attacks to branch decision-making variables as well as the attacks to control-data.
Cosmological and astrophysical constraints on tachyon dark energy models
Martins, C J A P
2016-01-01
Rolling tachyon field models are among the candidates suggested as explanations for the recent acceleration of the Universe. In these models the field is expected to interact with gauge fields and lead to variations of the fine-structure constant $\\alpha$. Here we take advantage of recent observational progress and use a combination of background cosmological observations of Type Ia supernovas and astrophysical and local measurements of $\\alpha$ to improve constraints on this class of models. We show that the constraints on $\\alpha$ imply that the field dynamics must be extremely slow, leading to a constraint of the present-day dark energy equation of state $(1+w_0)<2.4\\times10^{-7}$ at the $99.7\\%$ confidence level. Therefore current and forthcoming standard background cosmology observational probes can't distinguish this class of models from a cosmological constant, while detections of $\\alpha$ variations could possibly do so since they would have a characteristic redshift dependence.
Cosmological and astrophysical constraints on tachyon dark energy models
Martins, C. J. A. P.; Moucherek, F. M. O.
2016-06-01
Rolling tachyon field models are among the candidates suggested as explanations for the recent acceleration of the Universe. In these models the field is expected to interact with gauge fields and lead to variations of the fine-structure constant α . Here we take advantage of recent observational progress and use a combination of background cosmological observations of type Ia supernovas and astrophysical and local measurements of α to improve constraints on this class of models. We show that the constraints on α imply that the field dynamics must be extremely slow, leading to a constraint of the present-day dark energy equation of state (1 +w0)<2.4 ×10-7 at the 99.7% confidence level. Therefore current and forthcoming standard background cosmology observational probes cannot distinguish this class of models from a cosmological constant, while detections of α variations could possibly do so since they would have a characteristic redshift dependence.
Relativistic Mean-Field Models and Nuclear Matter Constraints
Dutra, M; Carlson, B V; Delfino, A; Menezes, D P; Avancini, S S; Stone, J R; Providência, C; Typel, S
2013-01-01
This work presents a preliminary study of 147 relativistic mean-field (RMF) hadronic models used in the literature, regarding their behavior in the nuclear matter regime. We analyze here different kinds of such models, namely: (i) linear models, (ii) nonlinear \\sigma^3+\\sigma^4 models, (iii) \\sigma^3+\\sigma^4+\\omega^4 models, (iv) models containing mixing terms in the fields \\sigma and \\omega, (v) density dependent models, and (vi) point-coupling ones. In the finite range models, the attractive (repulsive) interaction is described in the Lagrangian density by the \\sigma (\\omega) field. The isospin dependence of the interaction is modeled by the \\rho meson field. We submit these sets of RMF models to eleven macroscopic (experimental and empirical) constraints, used in a recent study in which 240 Skyrme parametrizations were analyzed. Such constraints cover a wide range of properties related to symmetric nuclear matter (SNM), pure neutron matter (PNM), and both SNM and PNM.
Modelling the pulse transformer in SPICE
Godlewska, Malgorzata; Górecki, Krzysztof; Górski, Krzysztof
2016-01-01
The paper is devoted to modelling pulse transformers in SPICE. It shows the character of the selected models of this element, points out their advantages and disadvantages, and presents the results of experimental verification of the considered models. These models are characterized by varying degrees of complexity - from linearly coupled linear coils to nonlinear electrothermal models. The study was conducted for transformer with ring cores made of a variety of ferromagnetic materials, while exciting the sinusoidal signal of a frequency 100 kHz and different values of load resistance. The transformers operating conditions under which the considered models ensure the acceptable accuracy of calculations are indicated.
Modeling Peak Oil and the Geological Constraints on Oil Production
Okullo, S.J.; Reynes, F.; Hofkes, M.W.
2014-01-01
We propose a model to reconcile the theory of inter-temporal non-renewable resource depletion with well-known stylized facts concerning the exploitation of exhaustible resources such as oil. Our approach introduces geological constraints into a Hotelling type extraction-exploration model. We show th
Modeling Peak Oil and the Geological Constraints on Oil Production
Okullo, S.J.; Reynes, F.; Hofkes, M.W.
2014-01-01
We propose a model to reconcile the theory of inter-temporal non-renewable resource depletion with well-known stylized facts concerning the exploitation of exhaustible resources such as oil. Our approach introduces geological constraints into a Hotelling type extraction-exploration model. We show th
Modeling peak oil and the geological constraints on oil production
Okullo, S.J.; Reynès, F.; Hofkes, M.W.
2015-01-01
We propose a model to reconcile the theory of inter-temporal non-renewable resource depletion with well-known stylized facts concerning the exploitation of exhaustible resources such as oil. Our approach introduces geological constraints into a Hotelling type extraction-exploration model. We show
Reduced order modeling of steady flows subject to aerodynamic constraints
DEFF Research Database (Denmark)
Zimmermann, Ralf; Vendl, Alexander; Goertz, Stefan
2014-01-01
A novel reduced-order modeling method based on proper orthogonal decomposition for predicting steady, turbulent flows subject to aerodynamic constraints is introduced. Model-order reduction is achieved by replacing the governing equations of computational fluid dynamics with a nonlinear weighted ...
Modeling peak oil and the geological constraints on oil production
Okullo, S.J.; Reynès, F.; Hofkes, M.W.
2015-01-01
We propose a model to reconcile the theory of inter-temporal non-renewable resource depletion with well-known stylized facts concerning the exploitation of exhaustible resources such as oil. Our approach introduces geological constraints into a Hotelling type extraction-exploration model. We show th
Barrier Lyapunov function-based model-free constraint position control for mechanical systems
Energy Technology Data Exchange (ETDEWEB)
Han, Seong Ik; Ha, Hyun Uk; Lee, Jang Myung [Pusan National University, Busan (Korea, Republic of)
2016-07-15
In this article, a motion constraint control scheme is presented for mechanical systems without a modeling process by introducing a barrier Lyapunov function technique and adaptive estimation laws. The transformed error and filtered error surfaces are defined to constrain the motion tracking error in the prescribed boundary layers. Unknown parameters of mechanical systems are estimated using adaptive laws derived from the Lyapunov function. Then, robust control used the conventional sliding mode control, which give rise to excessive chattering, is changed to finite time-based control to alleviate undesirable chattering in the control action and to ensure finite-time error convergence. Finally, the constraint controller from the barrier Lyapunov function is designed and applied to the constraint of the position tracking error of the mechanical system. Two experimental examples for the XY table and articulated manipulator are shown to evaluate the proposed control scheme.
On the interoperability of model-to-model transformation languages
Jouault, Frédéric; Kurtev, Ivan
2007-01-01
Transforming models is a crucial activity in Model Driven Engineering (MDE). With the adoption of the OMG QVT standard for model transformation languages, it is anticipated that the experience in applying model transformations in various domains will increase. However, the QVT standard is just one p
Has the Nordic Welfare Model Been Transformed?
DEFF Research Database (Denmark)
Greve, Bent; Kvist, Jon
2011-01-01
The Nordic welfare model is undergoing a fundamental transformation. Using Denmark we show how a universal welfare state model is gradually being transformed into an emergent multi-tiered welfare state. Whereas the Danish pension system's having become multi-tiered in the 1990s, with private...
Extending models for two-dimensional constraints
DEFF Research Database (Denmark)
Forchhammer, Søren
2009-01-01
Random fields in two dimensions may be specified on 2 times 2 elements such that the probabilities of finite configurations and the entropy may be calculated explicitly. The Pickard random field is one example where probability of a new (non-boundary) element is conditioned on three previous...... elements. To extend the concept we consider extending such a field such that a vector or block of elements is conditioned on a larger set of previous elements. Given a stationary model defined on 2 times 2 elements, iterative scaling is used to define the extended model. The extended model may be used...
New Results on Robust Model Predictive Control for Time-Delay Systems with Input Constraints
Directory of Open Access Journals (Sweden)
Qing Lu
2014-01-01
Full Text Available This paper investigates the problem of model predictive control for a class of nonlinear systems subject to state delays and input constraints. The time-varying delay is considered with both upper and lower bounds. A new model is proposed to approximate the delay. And the uncertainty is polytopic type. For the state-feedback MPC design objective, we formulate an optimization problem. Under model transformation, a new model predictive controller is designed such that the robust asymptotical stability of the closed-loop system can be guaranteed. Finally, the applicability of the presented results are demonstrated by a practical example.
A Probabilistic Model for Face Transformation with Application to Person Identification
Directory of Open Access Journals (Sweden)
Rose Kenneth
2004-01-01
Full Text Available A novel approach for content-based image retrieval and its specialization to face recognition are described. While most face recognition techniques aim at modeling faces, our goal is to model the transformation between face images of the same person. As a global face transformation may be too complex to be modeled directly, it is approximated by a collection of local transformations with a constraint that imposes consistency between neighboring transformations. Local transformations and neighborhood constraints are embedded within a probabilistic framework using two-dimensional hidden Markov models (2D HMMs. We further introduce a new efficient technique, called turbo-HMM (T-HMM for approximating intractable 2D HMMs. Experimental results on a face identification task show that our novel approach compares favorably to the popular eigenfaces and fisherfaces algorithms.
Modeling Network Transition Constraints with Hypergraphs
DEFF Research Database (Denmark)
Harrod, Steven
2011-01-01
Discrete time dynamic graphs are frequently used to model multicommodity flows or activity paths through constrained resources, but simple graphs fail to capture the interaction effects of resource transitions. The resulting schedules are not operationally feasible, and return inflated objective...
Fine-structure constant constraints on Bekenstein-type models
Leal, P M M; Ventura, L B
2014-01-01
Astrophysical tests of the stability of dimensionless fundamental couplings, such as the fine-structure constant $\\alpha$, are an area of much increased recent activity, following some indications of possible spacetime variations at the few parts per million level. Here we obtain updated constraints on the Bekenstein-Sandvik-Barrow-Magueijo model, which is arguably the simplest model allowing for $\\alpha$ variations. Recent accurate spectroscopic measurements allow us to improve previous constraints by about an order of magnitude. We briefly comment on the dependence of the results on the data sample, as well as on the improvements expected from future facilities.
Precision Electroweak Measurements and Constraints on the Standard Model
Alcaraz, J; Barberio, E; Bourilkov, D; Checchia, P; Chierici, R; Clare, R; D'Hondt, J; de la Cruz, B; de Jong, P; Della Ricca, G; Dierckxsens, M; Duchesneau, D; Duckeck, G; Elsing, M; Grünewald, M W; Gurtu, A; Hansen, J B; Hawkings, R; Jezequel, St; Jones, R W L; Kawamoto, T; Lançon, E; Liebig, W; Malgeri, L; Mele, S; Minard, M N; Mönig, K; Parkes, C; Parzefall, U; Pietrzyk, B; Quast, G; Renton, P B; Riemann, S; Sachs, K; Strässner, A; Strom, D; Tenchini, R; Teubert, F; Thomson, M A; Todorova-Nová, S; Valassi, A; Venturi, A; Voss, H; Ward, C P; Watson, N K; Wells, P S; Wynhoff, St
2007-01-01
This note presents constraints on Standard Model parameters using published and preliminary precision electroweak results measured at the electron-positron colliders LEP and SLC. The results are compared with precise electroweak measurements from other experiments, notably CDF and D{\\O}at the Tevatron. Constraints on the input parameters of the Standard Model are derived from the results obtained in high-$Q^2$ interactions, and used to predict results in low-$Q^2$ experiments, such as atomic parity violation, M{\\o}ller scattering, and neutrino-nucleon scattering.
Modeling of austenite to ferrite transformation
Indian Academy of Sciences (India)
Mohsen Kazeminezhad
2012-06-01
In this research, an algorithm based on the -state Potts model is presented for modeling the austenite to ferrite transformation. In the algorithm, it is possible to exactly track boundary migration of the phase formed during transformation. In the algorithm, effects of changes in chemical free energy, strain free energy and interfacial energies of austenite–austenite, ferrite–ferrite and austenite–ferrite during transformation are considered. From the algorithm, the kinetics of transformation and mean ferrite grain size for different cooling rates are calculated. It is found that there is a good agreement between the calculated and experimental results.
Quantum decoration transformation for spin models
Braz, F. F.; Rodrigues, F. C.; de Souza, S. M.; Rojas, Onofre
2016-09-01
It is quite relevant the extension of decoration transformation for quantum spin models since most of the real materials could be well described by Heisenberg type models. Here we propose an exact quantum decoration transformation and also showing interesting properties such as the persistence of symmetry and the symmetry breaking during this transformation. Although the proposed transformation, in principle, cannot be used to map exactly a quantum spin lattice model into another quantum spin lattice model, since the operators are non-commutative. However, it is possible the mapping in the "classical" limit, establishing an equivalence between both quantum spin lattice models. To study the validity of this approach for quantum spin lattice model, we use the Zassenhaus formula, and we verify how the correction could influence the decoration transformation. But this correction could be useless to improve the quantum decoration transformation because it involves the second-nearest-neighbor and further nearest neighbor couplings, which leads into a cumbersome task to establish the equivalence between both lattice models. This correction also gives us valuable information about its contribution, for most of the Heisenberg type models, this correction could be irrelevant at least up to the third order term of Zassenhaus formula. This transformation is applied to a finite size Heisenberg chain, comparing with the exact numerical results, our result is consistent for weak xy-anisotropy coupling. We also apply to bond-alternating Ising-Heisenberg chain model, obtaining an accurate result in the limit of the quasi-Ising chain.
A taste of Hamiltonian constraint in spin foam models
Bonzom, Valentin
2011-01-01
The asymptotics of some spin foam amplitudes for a quantum 4-simplex is known to display rapid oscillations whose frequency is the Regge action. In this note, we reformulate this result through a difference equation, asymptotically satisfied by these models, and whose semi-classical solutions are precisely the sine and the cosine of the Regge action. This equation is then interpreted as coming from the canonical quantization of a simple constraint in Regge calculus. This suggests to lift and generalize this constraint to the phase space of loop quantum gravity parametrized by twisted geometries. The result is a reformulation of the flat model for topological BF theory from the Hamiltonian perspective. The Wheeler-de-Witt equation in the spin network basis gives difference equations which are exactly recursion relations on the 15j-symbol. Moreover, the semi-classical limit is investigated using coherent states, and produces the expected results. It mimics the classical constraint with quantized areas, and for ...
Dark Matter Constraints on Composite Higgs Models
Fonseca, Nayara; Lessa, Andre; Lopez-Honorez, Laura
2015-01-01
In composite Higgs models the pseudo-Nambu-Goldstone Boson (pNGB) nature of the Higgs field is an interesting alternative for explaning the smallness of the electroweak scale with respect to the beyond the Standard Model scale. In non-minimal models additional pNGB states are present and can be a Dark Matter (DM) candidate, if there is an approximate symmetry suppressing their decay. Here we assume that the low energy effective theory (for scales much below the compositeness scale) corresponds to the Standard Model with a pNGB Higgs doublet and a pNGB DM multiplet. We derive general effective DM Lagrangians for several possible DM representations (under the SM gauge group), including the singlet, doublet and triplet cases. Within this framework we discuss how the DM observables (relic abundance, direct and indirect detection) constrain the dimension-6 operators induced by the strong sector assuming that DM behaves as a Weakly Interacting Particle (WIMP) and that the relic abundance is settled through the free...
Dark Matter constraints on composite Higgs models
Fonseca, Nayara; Funchal, Renata Zukanovich; Lessa, Andre; Lopez-Honorez, Laura
2015-06-01
In composite Higgs models the pseudo-Nambu-Goldstone Boson (pNGB) nature of the Higgs field is an interesting alternative for explaining the smallness of the electroweak scale with respect to the beyond the Standard Model scale. In non-minimal models additional pNGB states are present and can be a Dark Matter (DM) candidate, if there is an approximate symmetry suppressing their decay. Here we assume that the low energy effective theory (for scales much below the compositeness scale) corresponds to the Standard Model with a pNGB Higgs doublet and a pNGB DM multiplet. We derive general effective DM Lagrangians for several possible DM representations (under the SM gauge group), including the singlet, doublet and triplet cases. Within this framework we discuss how the DM observables (relic abundance, direct and indirect detection) constrain the dimension-6 operators induced by the strong sector assuming that DM behaves as a Weakly Interacting Particle (WIMP) and that the relic abundance is settled through the freeze-out mechanism. We also apply our general results to two specific cosets: SO(6)/SO(5) and SO(6)/SO(4)×SO(2), which contain a singlet and doublet DM candidate, respectively. In particular we show that if compositeness is a solution to the little hierarchy problem, representations larger than the triplet are strongly disfavored. Furthermore, we find that composite models can have viable DM candidates with much smaller direct detection cross-sections than their non-composite counterparts, making DM detection much more challenging.
Ontology Based Model Transformation Infrastructure
Göknil, A.; Topaloglu, N.Y.
2005-01-01
Using MDA in ontology development has been investigated in several works recently. The mappings and transformations between the UML constructs and the OWL elements to develop ontologies are the main concern of these research projects. We propose another approach in order to achieve the collaboration
Water Constraints in an Electric Sector Capacity Expansion Model
Energy Technology Data Exchange (ETDEWEB)
Macknick, Jordan [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Cohen, Stuart [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Newmark, Robin [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Martinez, Andrew [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Sullivan, Patrick [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Tidwell, Vince [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
2015-07-17
This analysis provides a description of the first U.S. national electricity capacity expansion model to incorporate water resource availability and costs as a constraint for the future development of the electricity sector. The Regional Energy Deployment System (ReEDS) model was modified to incorporate water resource availability constraints and costs in each of its 134 Balancing Area (BA) regions along with differences in costs and efficiencies of cooling systems. Water resource availability and cost data are from recently completed research at Sandia National Laboratories (Tidwell et al. 2013b). Scenarios analyzed include a business-as-usual 3 This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications. scenario without water constraints as well as four scenarios that include water constraints and allow for different cooling systems and types of water resources to be utilized. This analysis provides insight into where water resource constraints could affect the choice, configuration, or location of new electricity technologies.
Cosmological constraints on superconducting dark energy models
Keresztes, Zoltán; Harko, Tiberiu; Liang, Shi-Dong
2015-01-01
We consider cosmological tests of a scalar-vector-tensor gravitational model, in which the dark energy is included in the total action through a gauge invariant, electromagnetic type contribution. The ground state of dark energy, corresponding to a constant potential $V$ is a Bose-Einstein type condensate with spontaneously broken U(1) symmetry. In another words dark energy appears as a massive vector field emerging from a superposition of a massless vector and a scalar field, the latter corresponding to the Goldstone boson. Two particular cosmological models, corresponding to pure electric and pure magnetic type potentials, respectively are confronted with Type IA Supernovae and Hubble parameter data. In the electric case good fit is obtained along a narrow inclined stripe in the $\\Omega _{m}-\\Omega _{V}$ parameter plane, which includes the $\\Lambda $CDM limit. The other points on this admissible region represent superconducting dark energy as a sum of a cosmological constant and a time-evolving contribution...
Constraints on Dark Energy Models from Weak Gravity Conjecture
Institute of Scientific and Technical Information of China (English)
CHEN Xi-Ming; LIU Jie; GONG Yun-Gui
2008-01-01
@@ We study the constraints on the dark energy model with constant equation of state parameter w = p/p and the holographic dark energy model by using the weak gravity conjecture. The combination of weak gravity conjecture and the observational data gives w < -0.7 at the 3σ confidence level. The holographic dark energy model realized by a scalar field is in swampland.
Modeling Mathematical Programs with Equilibrium Constraints in Pyomo
Energy Technology Data Exchange (ETDEWEB)
Hart, William E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Siirola, John Daniel [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
2015-07-01
We describe new capabilities for modeling MPEC problems within the Pyomo modeling software. These capabilities include new modeling components that represent complementar- ity conditions, modeling transformations for re-expressing models with complementarity con- ditions in other forms, and meta-solvers that apply transformations and numeric optimization solvers to optimize MPEC problems. We illustrate the breadth of Pyomo's modeling capabil- ities for MPEC problems, and we describe how Pyomo's meta-solvers can perform local and global optimization of MPEC problems.
Classification of inflationary models and constraints on fundamental physics
Pieroni, Mauro
2016-01-01
This work is focused on the study of early time cosmology and in particular on the study of inflation. After an introduction on the standard Big Bang theory, we discuss the physics of CMB and we explain how its observations can be used to set constraints on cosmological models. We introduce inflation and we carry out its simplest realization by presenting the observables and the experimental constraints that can be set on inflationary models. The possibility of observing primordial gravitational waves (GWs) produced during inflation is discussed. We present the reasons to define a classification of inflationary models and introduce the \\beta-function formalism for inflation by explaining why in this framework we can naturally define a set of universality classes for inflationary models. Theoretical motivations to support the formulation of inflation in terms of this formalism are presented. Some generalized models of inflation are introduced and the extension of the \\beta-function formalism for inflation to t...
Constraints On Holographic Cosmological Models From Gamma Ray Bursts
Rivera, Alexander Bonilla
2016-01-01
We use Gamma Ray Bursts (GRBs) data to put additional constraints on a set of holographic dark energy models. GRBs are the most energetic events in the Universe and provide a complementary probe of dark energy by allowing the measurement of cosmic expansion history that extends to redshifts greater than 6 and they are complementary to SNIa test. We found that the LCDM model is the best fit to the data, although a preliminary statistical analysis seems to indicate that the holographic models studied show interesting agreement with observations, except Ricci Scale CPL model. These results show the importance of GRBs measurements to provide additional observational constraints to alternative cosmological models, which are necessary to clarify the way in the paradigm of dark energy or potential alternatives.
Cosmological constraint on Brans-Dicke Model
Li, Ji-Xia; Li, Yi-Chao; Gong, Yan; Chen, Xue-Lei
2015-01-01
We combine new Cosmic Microwave Background (CMB) data from Planck with Baryon Acoustic Oscillation (BAO) data to constrain the Brans-Dicke (BD) theory, in which the gravitational constant $G$ evolves with time. Observations of type Ia supernovae (SNeIa) provide another important set of cosmological data, as they may be regarded as standard candles after some empirical corrections. However, in theories that include modified gravity like the BD theory, there is some risk and complication when using the SNIa data because their luminosity may depend on $G$. In this paper, we assume a power law relation between the SNIa luminosity and $G$, but treat the power index as a free parameter. We then test whether the difference in distances measured with SNIa data and BAO data can be reduced in such a model. We also constrain the BD theory and cosmological parameters by making a global fit with the CMB, BAO and SNIa data set. For the CMB+BAO+SNIa data set, we find $0.08\\times10^{-2} < \\zeta <0.33\\times10^{-2} $ at ...
Solving Topological and Geometrical Constraints in Bridge Feature Model
Institute of Scientific and Technical Information of China (English)
PENG Weibing; SONG Liangliang; PAN Guoshuai
2008-01-01
The capacity that computer can solve more complex design problem was gradually increased.Bridge designs need a breakthrough in the current development limitations, and then become more intelli-gent and integrated. This paper proposes a new parametric and feature-based computer aided design (CAD) models which can represent families of bridge objects, includes knowledge representation, three-dimensional geometric topology relationships. The realization of a family member is found by solving first the geometdc constraints, and then the topological constraints. From the geometric solution, constraint equations are constructed. Topology solution is developed by feature dependencies graph between bridge objects. Finally, feature parameters are proposed to drive bridge design with feature parameters. Results from our implementation show that the method can help to facilitate bridge design.
Exploring a type-theoretic approach to accessibility constraint modelling
Pogodalla, Sylvain
2008-01-01
The type-theoretic modelling of DRT that [degroote06] proposed features continuations for the management of the context in which a clause has to be interpreted. This approach, while keeping the standard definitions of quantifier scope, translates the rules of the accessibility constraints of discourse referents inside the semantic recipes. In this paper, we deal with additional rules for these accessibility constraints. In particular in the case of discourse referents introduced by proper nouns, that negation does not block, and in the case of rhetorical relations that structure discourses. We show how this continuation-based approach applies to those accessibility constraints and how we can consider the parallel management of various principles.
A Constrained CA Model for Planning Simulation Incorporating Institutional Constraints
Institute of Scientific and Technical Information of China (English)
2010-01-01
In recent years,it is prevailing to simulate urban growth by means of cellular automata (CA in short) modeling,which is based on selforganizing theories and different from the system dynamic modeling.Since the urban system is definitely complex,the CA models applied in urban growth simulation should take into consideration not only the neighborhood influence,but also other factors influencing urban development.We bring forward the term of complex constrained CA (CC-CA in short) model,which integrates the constrained conditions of neighborhood,macro socio-economy,space and institution.Particularly,the constrained construction zoning,as one institutional constraint,is considered in the CC-CA modeling.In the paper,the conceptual CC-CA model is introduced together with the transition rules.Based on the CC-CA model for Beijing,we discuss the complex constraints to the urban development of,and we show how to set institutional constraints in planning scenario to control the urban growth pattern of Beijing.
The Reduced RUM as a Logit Model: Parameterization and Constraints.
Chiu, Chia-Yi; Köhn, Hans-Friedrich
2016-06-01
Cognitive diagnosis models (CDMs) for educational assessment are constrained latent class models. Examinees are assigned to classes of intellectual proficiency defined in terms of cognitive skills called attributes, which an examinee may or may not have mastered. The Reduced Reparameterized Unified Model (Reduced RUM) has received considerable attention among psychometricians. Markov Chain Monte Carlo (MCMC) or Expectation Maximization (EM) are typically used for estimating the Reduced RUM. Commercial implementations of the EM algorithm are available in the latent class analysis (LCA) routines of Latent GOLD and Mplus, for example. Fitting the Reduced RUM with an LCA routine requires that it be reparameterized as a logit model, with constraints imposed on the parameters. For models involving two attributes, these have been worked out. However, for models involving more than two attributes, the parameterization and the constraints are nontrivial and currently unknown. In this article, the general parameterization of the Reduced RUM as a logit model involving any number of attributes and the associated parameter constraints are derived. As a practical illustration, the LCA routine in Mplus is used for fitting the Reduced RUM to two synthetic data sets and to a real-world data set; for comparison, the results obtained by using the MCMC implementation in OpenBUGS are also provided.
MODELING COMPLIANT NON PENETRATION CONSTRAINT FOR VP MOTION SIMULATION
Institute of Scientific and Technical Information of China (English)
Wang Zheng; Tan Jianrong; Liu Zhenyu; Ji Yangjian
2005-01-01
A unilateral non-penetration constraint dynamical simulation model with friction is constructed based on compliant model for mechanical system VP (virtual prototyping) simulation. This model combines computer graphics with multi-body system dynamics. It avoids handling multiplicity of solution, such as cases of no solution, multi-solution brought about by friction during traditional construction of non-penetration constraint based on rigid model. At the same time, the realism of VE (virtual environment) is improved in process of simulation. Furthermore, the valid condition of rolling and sliding unilateral contact is constituted based on singular perturbation and linear complementary theory. Finally, the compliant method is verified by an interaction between a multi-legged robot and VE.
Samnett: the EMPS model with power flow constraints: implementation details
Energy Technology Data Exchange (ETDEWEB)
Helseth, Arild; Warland, Geir; Mo, Birger; Fosso, Olav B.
2011-12-15
This report describes the development and implementation of Samnett. Samnett is a new prototype for solving the coupled market and transmission network problem. The prototype is based on the EMPS model (Samkjoeringsmodellen). Results from the market model are distributed to a detailed transmission network model, where a DC power flow detects if there are overloads on monitored lines or interconnections. In case of overloads, power flow constraints are generated and added to the market problem. This report is an updated version of TR A6891 {sup I}mplementing Network Constraints in the EMPS model{sup .} It further elaborates on theoretical and implementation details in Samnett, but does not contain the case studies and file descriptions presented in TR A6891.(auth)
A Model of Technological Growth under Emission Constraints
Rovenskaya, E.
2006-01-01
We suggest and analyze a model of global technological growth under a prescribed constraint on the annual emission of greenhouse gases (GHG). The model assumes that industrial GHG emission is positively related to the world's production output driven by the development of the "production"technology stock. "Cleaning" technology is developed in parallel to keep the annual GHG emission within a "safety" zone. The ratio between annual investment in "cleaning" technology and annual investment in "...
Observational constraints on non-minimally coupled Galileon model
Jamil, Mubasher; Myrzakulov, Ratbay; 10.1140/epjc/s10052-013-2300-6
2013-01-01
As an extension of Dvali-Gabadadze-Porrati (DGP) model, the Galileon theory has been proposed to explain the "self-accelerating problem" and "ghost instability problem". In this Paper, we extend the Galileon theory by considering a non-minimally coupled Galileon scalar with gravity. We find that crossing of phantom divide line is possible for such model. Moreover we perform the statefinder analysis and $Om(z)$ diagnostic and constraint the model parameters from the latest Union 2 type Ia Supernova (SNe Ia) set and the baryonic acoustic oscillation (BAO). Using these data sets, we obtain the constraints $\\Omega_\\text{m0}=0.263_{-0.031}^{+0.031}$, $n=1.53_{-0.37}^{+0.21}$ (at the 95% confidence level) with $\\chi^2_{\\text{min}}=473.376$. Further we study the evolution of the equation of state parameter for the effective dark energy and observe that SNe Ia + BAO prefers a phantom-like dark energy.
CMB and reheating constraints to \\alpha-attractor inflationary models
Eshaghi, Mehdi; Riazi, Nematollah; Kiasatpour, Ahmad
2016-01-01
After Planck 2013, a broad class of inflationary models called \\alpha-attractors was developed which has universal observational predictions. For small values of the parameter \\alpha, the models have good consistency with the recent CMB data. In this work, we first calculate analytically (and verify numerically) the predictions of these models for spectral index, n_s and tensor-to-scalar ratio, r and then using BICEP2/Keck 2015 data we impose constraints on \\alpha-attractors. Then, we study the reheating in \\alpha-attractors. The reheating temperature, T_{re} and the number of e-folds during reheating, N_{re} are calculated as functions of n_s. Using these results, we determine the range of free parameter \\alpha for two clasees of \\alpha-attractors which satisfy the constraints of recent CMB data.
A novel fluence map optimization model incorporating leaf sequencing constraints.
Jin, Renchao; Min, Zhifang; Song, Enmin; Liu, Hong; Ye, Yinyu
2010-02-21
A novel fluence map optimization model incorporating leaf sequencing constraints is proposed to overcome the drawbacks of the current objective inside smoothing models. Instead of adding a smoothing item to the objective function, we add the total number of monitor unit (TNMU) requirement directly to the constraints which serves as an important factor to balance the fluence map optimization and leaf sequencing optimization process at the same time. Consequently, we formulate the fluence map optimization models for the trailing (left) leaf synchronized, leading (right) leaf synchronized and the interleaf motion constrained non-synchronized leaf sweeping schemes, respectively. In those schemes, the leaves are all swept unidirectionally from left to right. Each of those models is turned into a linear constrained quadratic programming model which can be solved effectively by the interior point method. Those new models are evaluated with two publicly available clinical treatment datasets including a head-neck case and a prostate case. As shown by the empirical results, our models perform much better in comparison with two recently emerged smoothing models (the total variance smoothing model and the quadratic smoothing model). For all three leaf sweeping schemes, our objective dose deviation functions increase much slower than those in the above two smoothing models with respect to the decreasing of the TNMU. While keeping plans in the similar conformity level, our new models gain much better performance on reducing TNMU.
BRST analysis of the gauged SU(2) WZW model and Darboux's transformations
Paschalis, J E
1996-01-01
The four dimensional SU(2) WZW model coupled to elecromagnetism is treated as a constraint system in the context of the BFV approach. We show that the Darboux's transformations which are used to diagonalize the canonical one-form in the Faddeev-Jackiw formalism, transform the fields of the model into BRST invariant ones. The same analysis is also carried out in the case of spinor electrodynamics.
Modeling and testing of ethernet transformers
Bowen, David
2011-12-01
Twisted-pair Ethernet is now the standard home and office last-mile network technology. For decades, the IEEE standard that defines Ethernet has required electrical isolation between the twisted pair cable and the Ethernet device. So, for decades, every Ethernet interface has used magnetic core Ethernet transformers to isolate Ethernet devices and keep users safe in the event of a potentially dangerous fault on the network media. The current state-of-the-art Ethernet transformers are miniature (explored which are capable of exceptional miniaturization or on-chip fabrication. This dissertation thoroughly explores the performance of the current commercial Ethernet transformers to both increase understanding of the device's behavior and outline performance parameters for replacement devices. Lumped element and distributed circuit models are derived; testing schemes are developed and used to extract model parameters from commercial Ethernet devices. Transfer relation measurements of the commercial Ethernet transformers are compared against the model's behavior and it is found that the tuned, distributed models produce the best transfer relation match to the measured data. Process descriptions and testing results on fabricated thin-film dielectric-core toroid transformers are presented. The best results were found for a 32-turn transformer loaded with 100Ω, the impedance of twisted pair cable. This transformer gave a flat response from about 10MHz to 40MHz with a height of approximately 0.45. For the fabricated transformer structures, theoretical methods to determine resistance, capacitance and inductance are presented. A special analytical and numerical analysis of the fabricated transformer inductance is presented. Planar cuts of magnetic slope fields around the dielectric-core toroid are shown that describe the effect of core height and winding density on flux uniformity without a magnetic core.
Pitts, J Brian
2013-01-01
In constrained dynamics, a first-class constraint typically does not_alone_ generate a gauge transformation. Each first-class constraint in Maxwell's theory changes the electric field by an arbitrary gradient, spoiling Gauss's law. The secondary p^i,_i=0 still holds, but being a function of derivatives of momenta, it is not directly about E (a function of derivatives of A_\\mu). Only a special combination of first-class constraints, the Anderson-Bergmann-Castellani gauge generator G, leaves E unchanged. This problem is avoided if one uses a first-class constraint as the generator of a_canonical transformation_; but that partly strips the canonical coordinates of physical meaning as electromagnetic potentials. Keeping gauge-invariant \\dot{q}- dH/dp= -E -p =0 supports using the primary rather than the extended Hamiltonian. The results extend the Lagrangian-oriented reforms of Castellani, Sugano, Pons, Salisbury, Shepley, etc. by showing the inequivalence of the extended Hamiltonian to the primary Hamiltonian (an...
Modeling and simulating of unloading welding transformer
Institute of Scientific and Technical Information of China (English)
无
2001-01-01
The simulation model of an unloading welding transformer was established on the basis of MATLAB software, and the modeling principle was described in detail in the paper. The model was made up of three sub-models, i.e. the linear inductor sub-model, the non-linear inductor sub-model and series connection sub-model controlled by current, and these sub-models were jointed together by means of segmented linearization. The simulating results showed that, in the conditions of the high convert frequency and the large cross section of the magnet core of a welding transformer, the non-linear inductor sub-model can be substituted by a linear inductor sub-model in the model; and the leakage reactance in the welding transformer is one of the main reasons of producing over-current and over-voltage in the inverter. The simulation results demonstrate that the over-voltage produced by leakage reactance is nearly two times of the input voltage supplied to the transformer, and the lasting time of over-voltage depends on time constant τ1. With reducing of τ1, the amplitude of the over-current will increase, and the lasting time becomes shorter. Contrarily, with increasing of τ1, the amplitude of the over-current will decrease, and the lasting time becomes longer. The model has played the important role for the development of the inverter resistance welding machine.
Observational constraints on the generalized $\\alpha$ attractor model
Shahalam, M; Myrzakul, Shynaray; Wang, Anzhong
2016-01-01
We study the generalized $\\alpha$ attractor model in context of late time cosmic acceleration; the model interpolates between freezing and thawing dark energy models. In the slow roll regime, the originally potential is modified whereas the modification ceases in the asymptotic regime and the effective potential behaves as quadratic. In our setting, field rolls slowly around the present epoch and mimics dark matter in future. We put observational constraints on the model parameters for which we use an integrated data base (SN+Hubble+BAO+CMB) for carrying out the data analysis.
Observational constraints on new generalized Chaplygin gas model
Liao, Kai; Zhu, Zong-Hong
2012-01-01
We use the latest data to investigate observational constraints on the new generalized Chaplygin gas (NGCG) model. Using the Markov Chain Monte Carlo (MCMC) method, we constrain the NGCG model with the type Ia supernovae (SNe Ia) from Union2 set (557 data), the usual baryonic acoustic oscillation (BAO) observation from the spectroscopic Sloan Digital Sky Survey (SDSS) data release 7 (DR7) galaxy sample, the cosmic microwave background (CMB) observation from the 7-year Wilkinson Microwave Anisotropy Probe (WMAP7) results, the newly revised $H(z)$ data, as well as a value of $\\theta_{BAO} (z=0.55) = (3.90 \\pm 0.38)^{\\circ}$ for the angular BAO scale. The constraint results for NGCG model are $\\omega_X = -1.0510_{-0.1685}^{+0.1563}(1\\sigma)_{-0.2398}^{+0.2226}(2\\sigma)$, $\\eta = 1.0117_{-0.0502}^{+0.0469}(1\\sigma)_{-0.0716}^{+0.0693}(2\\sigma)$, and $\\Omega_X = 0.7297_{-0.0276}^{+0.0229}(1\\sigma)_{-0.0402}^{+0.0329}(2\\sigma)$, which give a rather stringent constraint. From the results, we can see a phantom model ...
Observational constraints on the new generalized Chaplygin gas model
Institute of Scientific and Technical Information of China (English)
Kai Liao; Yu Pan; Zong-Hong Zhu
2013-01-01
We use the latest data to investigate observational constraints on the new generalized Chaplygin gas (NGCG) model.Using the Markov Chain Monte Carlo method,we constrain the NGCG model with type Ⅰa supernovae from the Union2 set (557 data),the usual baryonic acoustic oscillation (BAO) observation from the spectroscopic Sloan Digital Sky Survey data release 7 galaxy sample,the cosmic microwave background observation from the 7-year Wilkinson Microwave Anisotropy Probe results,newly revised data on H(z),as well as a value of θBAO (z =0.55) =(3.90° ± 0.38°) for the angular BAO scale.The constraint results for the NGCG model are ωx=-1.0510(-0.1685)(+0.1563)(1σ)(-0.2398)(+0.2226)(2σ),η=1.0117(-0.0502)(+0.0469)(1σ)(-0.0716)(+0.0693)(2σ) and Ωx=0.7297(-0.0276)(+0.0229)(1σ)(-0.0402)(+0.0329)(2σ),which give a rather stringent constraint.From the results,we can see that a phantom model is slightly favored and the proba-bility that energy transfers from dark matter to dark energy is a little larger than the inverse.
Light weakly coupled axial forces: models, constraints, and projections
Kahn, Yonatan; Krnjaic, Gordan; Mishra-Sharma, Siddharth; Tait, Tim M. P.
2017-05-01
We investigate the landscape of constraints on MeV-GeV scale, hidden U(1) forces with nonzero axial-vector couplings to Standard Model fermions. While the purely vector-coupled dark photon, which may arise from kinetic mixing, is a well-motivated scenario, several MeV-scale anomalies motivate a theory with axial couplings which can be UV-completed consistent with Standard Model gauge invariance. Moreover, existing constraints on dark photons depend on products of various combinations of axial and vector couplings, making it difficult to isolate the effects of axial couplings for particular flavors of SM fermions. We present a representative renormalizable, UV-complete model of a dark photon with adjustable axial and vector couplings, discuss its general features, and show how some UV constraints may be relaxed in a model with nonrenormalizable Yukawa couplings at the expense of fine-tuning. We survey the existing parameter space and the projected reach of planned experiments, briefly commenting on the relevance of the allowed parameter space to low-energy anomalies in π0 and 8Be∗ decay.
Light Weakly Coupled Axial Forces: Models, Constraints, and Projections
Kahn, Yonatan; Mishra-Sharma, Siddharth; Tait, Tim M P
2016-01-01
We investigate the landscape of constraints on MeV-GeV scale, hidden U(1) forces with nonzero axial-vector couplings to Standard Model fermions. While the purely vector-coupled dark photon, which may arise from kinetic mixing, is a well-motivated scenario, several MeV-scale anomalies motivate a theory with axial couplings which can be UV-completed consistent with Standard Model gauge invariance. Moreover, existing constraints on dark photons depend on products of various combinations of axial and vector couplings, making it difficult to isolate the effects of axial couplings for particular flavors of SM fermions. We present a representative renormalizable, UV-complete model of a dark photon with adjustable axial and vector couplings, discuss its general features, and show how some UV constraints may be relaxed in a model with nonrenormalizable Yukawa couplings at the expense of fine-tuning. We survey the existing parameter space and the projected reach of planned experiments, briefly commenting on the relevan...
Light Weakly Coupled Axial Forces: Models, Constraints, and Projections
Energy Technology Data Exchange (ETDEWEB)
Kahn, Yonatan [Princeton U.; Krnjaic, Gordan [Fermilab; Mishra-Sharma, Siddharth [Princeton U.; Tait, Tim P. [UC, Irvine
2016-09-28
We investigate the landscape of constraints on MeV-GeV scale, hidden U(1) forces with nonzero axial-vector couplings to Standard Model fermions. While the purely vector-coupled dark photon, which may arise from kinetic mixing, is a well-motivated scenario, several MeV-scale anomalies motivate a theory with axial couplings which can be UV-completed consistent with Standard Model gauge invariance. Moreover, existing constraints on dark photons depend on products of various combinations of axial and vector couplings, making it difficult to isolate the effects of axial couplings for particular flavors of SM fermions. We present a representative renormalizable, UV-complete model of a dark photon with adjustable axial and vector couplings, discuss its general features, and show how some UV constraints may be relaxed in a model with nonrenormalizable Yukawa couplings at the expense of fine-tuning. We survey the existing parameter space and the projected reach of planned experiments, briefly commenting on the relevance of the allowed parameter space to low-energy anomalies in pi^0 and 8-Be* decay.
Relativistic mean-field models and nuclear matter constraints
Energy Technology Data Exchange (ETDEWEB)
Dutra, M.; Lourenco, O.; Carlson, B. V. [Departamento de Fisica, Instituto Tecnologico de Aeronautica-CTA, 12228-900, Sao Jose dos Campos, SP (Brazil); Delfino, A. [Instituto de Fisica, Universidade Federal Fluminense, 24210-150, Boa Viagem, Niteroi, RJ (Brazil); Menezes, D. P.; Avancini, S. S. [Departamento de Fisica, CFM, Universidade Federal de Santa Catarina, CP. 476, CEP 88.040-900, Florianopolis, SC (Brazil); Stone, J. R. [Oxford Physics, University of Oxford, OX1 3PU Oxford (United Kingdom) and Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996 (United States); Providencia, C. [Centro de Fisica Computacional, Department of Physics, University of Coimbra, P-3004-516 Coimbra (Portugal); Typel, S. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Theorie, Planckstrasse 1,D-64291 Darmstadt (Germany)
2013-05-06
This work presents a preliminary study of 147 relativistic mean-field (RMF) hadronic models used in the literature, regarding their behavior in the nuclear matter regime. We analyze here different kinds of such models, namely: (i) linear models, (ii) nonlinear {sigma}{sup 3}+{sigma}{sup 4} models, (iii) {sigma}{sup 3}+{sigma}{sup 4}+{omega}{sup 4} models, (iv) models containing mixing terms in the fields {sigma} and {omega}, (v) density dependent models, and (vi) point-coupling ones. In the finite range models, the attractive (repulsive) interaction is described in the Lagrangian density by the {sigma} ({omega}) field. The isospin dependence of the interaction is modeled by the {rho} meson field. We submit these sets of RMF models to eleven macroscopic (experimental and empirical) constraints, used in a recent study in which 240 Skyrme parametrizations were analyzed. Such constraints cover a wide range of properties related to symmetric nuclear matter (SNM), pure neutron matter (PNM), and both SNM and PNM.
First cosmological constraints on the Superfluid Chaplygin gas model
Lazkoz, Ruth; Salzano, Vincenzo
2012-01-01
In this work we set observational constraints of the Superfluid Chaplygin gas model, which gives a unified description of the dark sector of the Universe as a Bose-Einstein condensate (BEC) that behaves as dark energy (DE) while it is in the ground state and as dark matter (DM) when it is in the excited state. We first show and perform the various steps leading to a form of the equations suitable for the observational tests to be carried out. Then, by using a Markov Chain Monte Carlo (MCMC) code, we constrain the model with a sample of cosmology-independent long gamma-ray bursts (LGRBs) calibrated using their Type I Fundamental Plane, as well as the Union2.1 set and observational Hubble parameter data. In this analysis, using our cosmological constraints, we sketch the effective equation of state parameter and deceleration parameter, and we also obtain the redshift of the transition from deceleration to acceleration: $z_t$.
Application of an analytical phase transformation model
Institute of Scientific and Technical Information of China (English)
LIU Feng; WANG Hai-feng; YANG Chang-lin; CHEN Zheng; YANG Wei; YANG Gen-cang
2006-01-01
Employing isothermal and isochronal differential scanning calorimetry, an analytical phase transformation model was used to study the kinetics of crystallization of amorphous Mg82.3Cu17.7 and Pd40Cu30P20Ni10 alloys. The analytical model comprised different combinations of various nucleation and growth mechanisms for a single transformation. Applying different combinations of nucleation and growth mechanisms, the nucleation and growth modes and the corresponding kinetic and thermodynamic parameters, have been determined. The influence of isothermal pre-annealing on subsequent isochronal crystallization kinetics with the increase of pre-annealing can be analyzed. The results show that the changes of the growth exponent, n, and the effective overall activation energy Q, occurring as function of the degree of transformation, do not necessarily imply a change of nucleation and growth mechanisms, i.e. such changes can occur while the transformation is isokinetic.
Correlating Formal Semantic Models of Reo Connectors: Connector Coloring and Constraint Automata
Directory of Open Access Journals (Sweden)
Sung-Shik T.Q. Jongmans
2011-07-01
Full Text Available Over the past decades, coordination languages have emerged for the specification and implementation of interaction protocols for communicating software components. This class of languages includes Reo, a platform for compositional construction of connectors. In recent years, various formalisms for describing the behavior of Reo connectors have come to existence, each of them serving its own purpose. Naturally, questions about how these models relate to each other arise. From a theoretical point of view, answers to these questions provide us with better insight into the fundamentals of Reo, while from a more practical perspective, these answers broaden the applicability of Reo's development tools. In this paper, we address one of these questions: we investigate the equivalence between coloring models and constraint automata, the two most dominant and practically relevant semantic models of Reo. More specifically, we define operators that transform one model to the other (and vice versa, prove their correctness, and show that they distribute over composition. To ensure that the transformation operators map one-to-one (instead of many-to-one, we extend coloring models with data constraints. Though primarily a theoretical contribution, we sketch some potential applications of our results: the broadening of the applicability of existing tools for connector verification and animation.
Rule-based transformations for geometric modelling
Directory of Open Access Journals (Sweden)
Thomas Bellet
2011-02-01
Full Text Available The context of this paper is the use of formal methods for topology-based geometric modelling. Topology-based geometric modelling deals with objects of various dimensions and shapes. Usually, objects are defined by a graph-based topological data structure and by an embedding that associates each topological element (vertex, edge, face, etc. with relevant data as their geometric shape (position, curve, surface, etc. or application dedicated data (e.g. molecule concentration level in a biological context. We propose to define topology-based geometric objects as labelled graphs. The arc labelling defines the topological structure of the object whose topological consistency is then ensured by labelling constraints. Nodes have as many labels as there are different data kinds in the embedding. Labelling constraints ensure then that the embedding is consistent with the topological structure. Thus, topology-based geometric objects constitute a particular subclass of a category of labelled graphs in which nodes have multiple labels.
Rule-based transformations for geometric modelling
Bellet, Thomas; Gall, Pascale Le; 10.4204/EPTCS.48.5
2011-01-01
The context of this paper is the use of formal methods for topology-based geometric modelling. Topology-based geometric modelling deals with objects of various dimensions and shapes. Usually, objects are defined by a graph-based topological data structure and by an embedding that associates each topological element (vertex, edge, face, etc.) with relevant data as their geometric shape (position, curve, surface, etc.) or application dedicated data (e.g. molecule concentration level in a biological context). We propose to define topology-based geometric objects as labelled graphs. The arc labelling defines the topological structure of the object whose topological consistency is then ensured by labelling constraints. Nodes have as many labels as there are different data kinds in the embedding. Labelling constraints ensure then that the embedding is consistent with the topological structure. Thus, topology-based geometric objects constitute a particular subclass of a category of labelled graphs in which nodes hav...
Six Sigma Driven Enterprise Model Transformation
Directory of Open Access Journals (Sweden)
Raymond Vella
2009-10-01
Full Text Available Enterprise architecture methods provide a structured system to understand enterprise activities. However, existing enterprise modelling methodologies take static views of the enterprise and do not naturally lead to a path of improvement during enterprise model transformation. This paper discusses the need for a methodology to facilitate changes for improvement in an enterprise. The six sigma methodology is proposed as the tool to facilitate progressive and continual Enterprise Model Transformation to allow businesses to adapt to meet increased customer expectation and global competition. An alignment of six sigma with phases of GERAM life cycle is described with inclusion of Critical-To-Satisfaction (CTS requirements. The synergies of combining the two methodologies are presented in an effort to provide a more culturally embedded framework for Enterprise Model Transformation that builds on the success of six sigma.
Modeling of Pulsed Transformer with Nanocrystalline Cores
Directory of Open Access Journals (Sweden)
Amir Baktash
2014-07-01
Full Text Available Recently tape wound cores, due to their excellent properties, are widely used in transformers for pulsed or high frequency applications. The spiral structure of these cores affects the flux distribution inside the core and causes complication of the magnetic analysis and consequently the circuit analysis. In this paper, a model based on reluctance networks method is used to analyze the magnetic flux in toroidal wound cores and losses calculation. A Preisach based hysteresis model is included in the model to consider the nonlinear characteristic of the core. Magnetic losses are calculated by having the flux density in different points of the core and using the hysteresis model. A transformer for using in a series resonant converter is modeled and implemented. The modeling results are compared with experimental measurements and FEM results to evaluate the validity of the model. Comparisons show the accuracy of the model besides its simplicity and fast convergence.
Modeling of Current Transformers Under Saturation Conditions
Directory of Open Access Journals (Sweden)
Martin Prochazka
2006-01-01
Full Text Available During a short circuit the input signal of the relay can be distort by the magnetic core saturation of the current transformer. It is useful to verify the behavior of CT by a mathematical model. The paper describes one phase and three phase models and it presents some methods of how to analyze and classify a deformed secondary current
Analysis of Crosscutting in Model Transformations
Berg, van den K.G.; Tekinerdogan, B.; Nguyen, H.; Aagedal, J.; Neple, T.; Oldevik, J.
2006-01-01
This paper describes an approach for the analysis of crosscutting in model transformations in the Model Driven Architecture (MDA). Software architectures should be amenable to changes in user requirements and technological platforms. Impact analysis of changes can be based on traceability of archite
Energy Technology Data Exchange (ETDEWEB)
Meyers, R E; Cederwall, R T; Ohmstede, W D; aufm Kampe, W
1976-01-01
Several steps are described that have been taken to advance the method of ''interpolation'' associated with meteorological measurements. These newer methods incorporate some physical constraints into the interpolation. It is the intent of this paper to qualitatively describe early fruits of a joint project at Brookhaven National Laboratory and White Sands Missile Range which has as its objective the formulation of a numerical objective methodology for reconstructing the meteorological fields suitable for the exercise of meso/regional scale transport, chemical and radioactive transformation, and diffusion models.
Consistent constraints on the Standard Model Effective Field Theory
Berthier, Laure
2015-01-01
We develop the global constraint picture in the (linear) effective field theory generalisation of the Standard Model, incorporating data from detectors that operated at PEP, PETRA, TRISTAN, SpS, Tevatron, SLAC, LEPI and LEP II, as well as low energy precision data. We fit one hundred observables. We develop a theory error metric for this effective field theory, which is required when constraints on parameters at leading order in the power counting are to be pushed to the percent level, or beyond, unless the cut off scale is assumed to be large, $\\Lambda \\gtrsim \\, 3 \\, {\\rm TeV}$. We more consistently incorporate theoretical errors in this work, avoiding this assumption, and as a direct consequence bounds on some leading parameters are relaxed. We show how an $\\rm S,T$ analysis is modified by the theory errors we include as an illustrative example.
Cosmological constraints on spontaneous R-symmetry breaking models
Energy Technology Data Exchange (ETDEWEB)
Hamada, Yuta; Kobayashi, Tatsuo [Kyoto Univ. (Japan). Dept. of Physics; Kamada, Kohei [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Ookouchi, Yutaka [Kyoto Univ. (Japan). Dept. of Physics; Kyoto Univ. (Japan). The Hakubi Center for Advanced Research and Dept. of Physics
2012-11-15
We study general constraints on spontaneous R-symmetry breaking models coming from the cosmological effects of the pseudo Nambu-Goldstone bosons, R-axions. They are substantially produced in the early Universe and may cause several cosmological problems. We focus on relatively long-lived R-axions and find that in a wide range of parameter space, models are severely constrained. In particular, R-axions with mass less than 1 MeV are generally ruled out for relatively high reheating temperature, T{sub R}>10 GeV.
CMB Constraints on Reheating Models with Varying Equation of State
de Freitas, Rodolfo C
2015-01-01
The temperature at the end of reheating and the length of this cosmological phase can be bound to the inflationary observables if one considers the cosmological evolution from the time of Hubble crossing until today. There are many examples in the literature where it is made for single-field inflationary models and a constant equation of state during reheating. We adopt two simple varying equation of state parameters during reheating, combine the allowed range of the reheating parameters with the observational limits of the scalar perturbations spectral index and compare the constraints of some inflationary models with the case of a constant equation of state parameter during reheating.
Explicit examples of DIM constraints for network matrix models
Awata, Hidetoshi; Matsumoto, Takuya; Mironov, Andrei; Morozov, Alexei; Morozov, Andrey; Ohkubo, Yusuke; Zenkevich, Yegor
2016-01-01
Dotsenko-Fateev and Chern-Simons matrix models, which describe Nekrasov functions for SYM theories in different dimensions, are all incorporated into network matrix models with the hidden Ding-Iohara-Miki (DIM) symmetry. This lifting is especially simple for what we call balanced networks. Then, the Ward identities (known under the names of Virasoro/W-constraints or loop equations or regularity condition for qq-characters) are also promoted to the DIM level, where they all become corollaries of a single identity.
Neural Modeling and Control of Diesel Engine with Pollution Constraints
Ouladsine, Mustapha; Dovifaaz, Xavier; 10.1007/s10846-005-3806-y
2009-01-01
The paper describes a neural approach for modelling and control of a turbocharged Diesel engine. A neural model, whose structure is mainly based on some physical equations describing the engine behaviour, is built for the rotation speed and the exhaust gas opacity. The model is composed of three interconnected neural submodels, each of them constituting a nonlinear multi-input single-output error model. The structural identi?cation and the parameter estimation from data gathered on a real engine are described. The neural direct model is then used to determine a neural controller of the engine, in a specialized training scheme minimising a multivariable criterion. Simulations show the effect of the pollution constraint weighting on a trajectory tracking of the engine speed. Neural networks, which are ?exible and parsimonious nonlinear black-box models, with universal approximation capabilities, can accurately describe or control complex nonlinear systems, with little a priori theoretical knowledge. The present...
Including Overweight or Obese Students in Physical Education: A Social Ecological Constraint Model
Li, Weidong; Rukavina, Paul
2012-01-01
In this review, we propose a social ecological constraint model to study inclusion of overweight or obese students in physical education by integrating key concepts and assumptions from ecological constraint theory in motor development and social ecological models in health promotion and behavior. The social ecological constraint model proposes…
Modeling and Measurement Constraints in Fault Diagnostics for HVAC Systems
Energy Technology Data Exchange (ETDEWEB)
Najafi, Massieh; Auslander, David M.; Bartlett, Peter L.; Haves, Philip; Sohn, Michael D.
2010-05-30
Many studies have shown that energy savings of five to fifteen percent are achievable in commercial buildings by detecting and correcting building faults, and optimizing building control systems. However, in spite of good progress in developing tools for determining HVAC diagnostics, methods to detect faults in HVAC systems are still generally undeveloped. Most approaches use numerical filtering or parameter estimation methods to compare data from energy meters and building sensors to predictions from mathematical or statistical models. They are effective when models are relatively accurate and data contain few errors. In this paper, we address the case where models are imperfect and data are variable, uncertain, and can contain error. We apply a Bayesian updating approach that is systematic in managing and accounting for most forms of model and data errors. The proposed method uses both knowledge of first principle modeling and empirical results to analyze the system performance within the boundaries defined by practical constraints. We demonstrate the approach by detecting faults in commercial building air handling units. We find that the limitations that exist in air handling unit diagnostics due to practical constraints can generally be effectively addressed through the proposed approach.
A delay-time model with safety constraint
Energy Technology Data Exchange (ETDEWEB)
Aven, Terje [University of Stavanger, 4036 Stavanger (Norway)], E-mail: terje.aven@uis.no; Castro, I.T. [Departamento de Matematicas, Escuela Politecnica, Universidad de Extremadura, 10071 Caceres (Spain)], E-mail: inmatorres@unex.es
2009-02-15
We consider the basic delay-time model in which a system has three states, the perfect functioning state, a defective state and the failure state. The system is deteriorating and to reduce the number of failures, preventive replacements are carried out when the system is in the defective state. The time in the defective state is referred to as the delay time. Inspections are required to check whether the system is in the defective state. System failures are safety critical and to control the risk, management considers two types of safety constraints: (i) the probability of at least one failure in the interval [0,A] should not exceed a fixed probability {omega}{sub 1} and (ii) the fraction of time the system is in the defective state should not exceed a fixed limit {omega}{sub 2}. The problem is to determine optimal inspection intervals T, minimizing the expected discounted costs under the safety constraints. Conditions are established for when the safety constraints affect the optimal inspection time and causes increased costs.
A point cloud modeling method based on geometric constraints mixing the robust least squares method
Yue, JIanping; Pan, Yi; Yue, Shun; Liu, Dapeng; Liu, Bin; Huang, Nan
2016-10-01
The appearance of 3D laser scanning technology has provided a new method for the acquisition of spatial 3D information. It has been widely used in the field of Surveying and Mapping Engineering with the characteristics of automatic and high precision. 3D laser scanning data processing process mainly includes the external laser data acquisition, the internal industry laser data splicing, the late 3D modeling and data integration system. For the point cloud modeling, domestic and foreign researchers have done a lot of research. Surface reconstruction technology mainly include the point shape, the triangle model, the triangle Bezier surface model, the rectangular surface model and so on, and the neural network and the Alfa shape are also used in the curved surface reconstruction. But in these methods, it is often focused on single surface fitting, automatic or manual block fitting, which ignores the model's integrity. It leads to a serious problems in the model after stitching, that is, the surfaces fitting separately is often not satisfied with the well-known geometric constraints, such as parallel, vertical, a fixed angle, or a fixed distance. However, the research on the special modeling theory such as the dimension constraint and the position constraint is not used widely. One of the traditional modeling methods adding geometric constraints is a method combing the penalty function method and the Levenberg-Marquardt algorithm (L-M algorithm), whose stability is pretty good. But in the research process, it is found that the method is greatly influenced by the initial value. In this paper, we propose an improved method of point cloud model taking into account the geometric constraint. We first apply robust least-squares to enhance the initial value's accuracy, and then use penalty function method to transform constrained optimization problems into unconstrained optimization problems, and finally solve the problems using the L-M algorithm. The experimental results
Abazajian, Kevork N.; Beacom, John F.; Bell, Nicole F.
2002-01-01
We assess a mechanism which can transform neutrino-antineutrino asymmetries between flavors in the early universe, and confirm that such transformation is unavoidable in the near bi-maximal framework emerging for the neutrino mixing matrix. We show that the process is a standard Mikheyev-Smirnov-Wolfenstein flavor transformation dictated by a synchronization of momentum states. We also show that flavor ``equilibration'' is a special feature of maximal mixing, and carefully examine new constra...
Singlet-Doublet model: dark matter searches and LHC constraints
Energy Technology Data Exchange (ETDEWEB)
Calibbi, Lorenzo [State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics,Chinese Academy of Sciences,Beijing 100190 (China); Service de Physique Théorique, Université Libre de Bruxelles,C.P. 225, B-1050, Brussels (Belgium); Mariotti, Alberto; Tziveloglou, Pantelis [Theoretische Natuurkunde and IIHE/ELEM, Vrije Universiteit Brussel,and International Solvay Institutes,Pleinlaan 2, B-1050 Brussels (Belgium)
2015-10-19
The Singlet-Doublet model of dark matter is a minimal extension of the Standard Model with dark matter that is a mixture of a singlet and a non-chiral pair of electroweak doublet fermions. The stability of dark matter is ensured by the typical parity symmetry, and, similar to a ‘Bino-Higgsino’ system, the extra matter content improves gauge coupling unification. We revisit the experimental constraints on the Singlet-Doublet dark matter model, combining the most relevant bounds from direct (spin independent and spin dependent) and indirect searches. We show that such comprehensive analysis sets strong constraints on a large part of the 4-dimensional parameter space, closing the notorious ‘blind-spots’ of spin independent direct searches. Our results emphasise the complementarity of direct and indirect searches in probing dark matter models in diverse mass scale regimes. We also discuss the LHC bounds on such scenario, which play a relevant role in the low mass region of the dark matter candidate.
Singlet-Doublet Model: Dark matter searches and LHC constraints
Calibbi, Lorenzo; Tziveloglou, Pantelis
2015-01-01
The Singlet-Doublet model of dark matter is a minimal extension of the Standard Model with dark matter that is a mixture of a singlet and a non-chiral pair of electroweak doublet fermions. The stability of dark matter is ensured by the typical parity symmetry, and, similar to a "Bino-Higgsino" system, the extra matter content improves gauge coupling unification. We revisit the experimental constraints on the Singlet-Doublet dark matter model, combining the most relevant bounds from direct (spin independent and spin dependent) and indirect searches. We show that such comprehensive analysis sets strong constraints on a large part of the 4-dimensional parameter space, closing the notorious "blind-spots" of spin independent direct searches. Our results emphasise the complementarity of direct and indirect searches in probing dark matter models in diverse mass scale regimes. We also discuss the LHC bounds on such scenario, which play a relevant role in the low mass region of the dark matter candidate.
Asymptotic dynamics of a frustrated model with spherical constraint
Energy Technology Data Exchange (ETDEWEB)
Mendoza-Coto, Alejandro [Departamento de Física, Universidade Federal do Rio Grande do Sul, CP 15051, 91501-970 Porto Alegre (Brazil); Díaz-Méndez, Rogelio, E-mail: rogelio@fisica.uh.cu [Nanophysics Group, Electric Engineering Faculty, CUJAE, CP 19390, La Habana (Cuba); Group of Complex Systems, Physics Faculty, University of Havana, CP 10400, La Habana (Cuba)
2013-11-15
We solve the Langevin dynamics of a continuum model with a spherical constraint, considering a ferromagnetic exchange and a long-range antiferromagnetic interaction. Analytical results within the Hartree approximation show an equivalence in the form of spatial and auto-correlation functions in the long time regime between this model and the recently studied Ginzburg–Landau frustrated model. The low-temperature behavior is discussed in the context of glassy dynamics. The emergence of interesting features regarding the establishment of the saturated phase is also analyzed in the view of recent literature. - Highlights: • We solve the long-time dynamics of a model with ferro and antiferromagnetic interactions and spherical restriction. • We find the critical behavior of spatial and self-correlations. • The new results are analyzed in the frame of existing literature on glassy states and thin films.
Theory and Model for Martensitic Transformations
DEFF Research Database (Denmark)
Lindgård, Per-Anker; Mouritsen, Ole G.
1986-01-01
Martensitic transformations are shown to be driven by the interplay between two fluctuating strain components. No soft mode is needed, but a central peak occurs representing the dynamics of strain clusters. A two-dimensional magnetic-analog model with the martensitic-transition symmetry...
Numerical modeling of transformer inrush currents
Cardelli, E.; Faba, A.
2014-02-01
This paper presents an application of a vector hysteresis model to the prediction of the inrush current due the arbitrary initial excitation of a transformer after a fault. The approach proposed seems promising in order to predict the transient overshoot in current and the optimal time to close the circuit after the fault.
Numerical modeling of transformer inrush currents
Energy Technology Data Exchange (ETDEWEB)
Cardelli, E. [Department of Industrial Engineering, University of Perugia, I-06125 Perugia (Italy); Center for Electric and Magnetic Applied Research (Italy); Faba, A., E-mail: faba@unipg.it [Department of Industrial Engineering, University of Perugia, I-06125 Perugia (Italy); Center for Electric and Magnetic Applied Research (Italy)
2014-02-15
This paper presents an application of a vector hysteresis model to the prediction of the inrush current due the arbitrary initial excitation of a transformer after a fault. The approach proposed seems promising in order to predict the transient overshoot in current and the optimal time to close the circuit after the fault.
Model-independent constraints on the cosmic opacity
Holanda, R F L; Alcaniz, J S
2012-01-01
We use current measurements of the expansion rate $H(z)$ and cosmic background radiation bounds on the spatial curvature of the Universe to impose cosmological model-independent constraints on cosmic opacity. To perform our analyses, we compare opacity-free distance modulus from $H(z)$ data with those from two supernovae Ia compilations, namely, the Union2 and Sloan Digital Sky Survey samples. The influence of different SNe Ia light-curve fitters (SALT2 and MLCS2K2) on the results is also discussed. We find that these fitters present a significant conflict, with the MLCS2K2 method being incompatible with a flat and transparent universe.
Jets from Young Stars I: Models and Constraints
Ferreira, Jonathan; Dougados, Catherine; Whelan, Emma
2007-09-01
This volume contains the edited lecture notes of the First JETSET School on Jets from Young Stars: Models and Constraints, held by the Marie Curie Research and Training Network on JET Simulations, Experiments and Theory. At this school the lecturers gave an introduction to observational properties and basic models describing the launching and collimation mechanisms of jets. The first half of the book is devoted to general observational constraints, covering the outflow phenomenon in young stars, the identification of magneto-centrifugal processes as the main jet driving mechanism, and the magnetic interaction between the star and its accretion disc. The second half of the book is devoted to theoretical knowledge of magneto-hydrodynamic processes pertinent to the jet launching mechanism in young stars. This comprises a general introduction to magneto-hydrodynamics, a description of the role of MHD processes in Standard Accretion Discs, and the physics of steady state MHD o! utflows, from the basic concepts and equations to modern self-similar solutions. Further lectures detail the various classes of steady magnetic-wind models currently discussed in the context of protostellar jets.
Modeling of open bank disturbution transformer connections
Lorber, Christa Kaye
1995-01-01
Distribution transformers are an essential part of any power distribution system. In order to thoroughly simulate and analyze such a system, accurate models must be developed that make use of readily available field data. In addition, unbalanced loading situations, which are encountered frequently in distribution transfonner utilization, must be handled properly. These requirements form the basis for the modeling of the open-wye/open-delta and open-delta/open-delta distribution...
Constraints in models and implementations of (VR) geo-info systems
Louwsma, J.; Zlatanova, S.; Lammeren, van R.J.A.; Oosterom, van P.
2005-01-01
Constraints are important elements of every modelling process but until now they have not received much attention in GIS. In GIS, constraints are conditions, which always have to be valid (true) within the model populated with real geographic object instances. In this paper we argue that constraints
LHC constraints on 3-3-1 models
Energy Technology Data Exchange (ETDEWEB)
Salazar, Camilo [Instituto de Física, Universidad de Antioquia,Calle 70 No. 52-21, Medellín (Colombia); Benavides, Richard H. [Facultad de Ciencias Exactas y Aplicadas, Instituto Tecnológico Metropolitano,Calle 73 No 76 A - 354, Vía el Volador, Medellín (Colombia); Ponce, William A. [Instituto de Física, Universidad de Antioquia,Calle 70 No. 52-21, Medellín (Colombia); Rojas, Eduardo [Instituto de Física, Universidad de Antioquia,Calle 70 No. 52-21, Medellín (Colombia); Laboratorio de Física Teórica e Computação Científica, Universidade Cruzeiro do Sul,01506-000, São Paulo (Brazil)
2015-07-20
The ATLAS detector data on di-lepton production is used in order to impose constraints on Z{sup ′} boson masses associated with a variety of 3-3-1 and E{sub 6} motivated Z{sup ′} models. Lower mass bounds for the different models are established at 95% confidence level. Our numerical analysis is extrapolated up to 14 TeV, and further to 30 TeV and 100 TeV, for a broad range of luminosities. Some of our results can be compared with the ATLAS published bounds, being, for those cases, in fairly good agreement. We also report the vector and axial charges for all the 3-3-1-motivated Z{sup ′} models without exotic electric charges for leptons, known in the literature. To the best of our knowledge most of this charges were not reported before.
Age constraints and fine tuning in VAMP models
Franca, U; Franca, Urbano; Rosenfeld, Rogerio
2004-01-01
VAMP (VAriable-Mass Particles) scenarios, in which the mass of the cold dark matter particles is a function of the scalar field responsible for the present acceleration of the universe, have been proposed as a solution to the cosmic coincidence problem, since in the attractor regime both dark energy and dark matter scale in the same way. We have calculated the age of the universe for an ensemble of models in this scenario obtaining $t_0 = 15.2^{+1.1}_{-0.8}$ Gyr, which is in poor agreement with the recent results obtained by the WMAP satellite. We show that observational constraints, particularly the age of the universe, require a strong fine tuning in the model. We conclude that VAMP models have difficulties to simultaneously account for the observed age of the universe and the current value of the dark energy equation of state.
Probabilistic Constraint Programming for Parameters Optimisation of Generative Models
Zanin, Massimiliano; Sousa, Pedro A C; Cruz, Jorge
2015-01-01
Complex networks theory has commonly been used for modelling and understanding the interactions taking place between the elements composing complex systems. More recently, the use of generative models has gained momentum, as they allow identifying which forces and mechanisms are responsible for the appearance of given structural properties. In spite of this interest, several problems remain open, one of the most important being the design of robust mechanisms for finding the optimal parameters of a generative model, given a set of real networks. In this contribution, we address this problem by means of Probabilistic Constraint Programming. By using as an example the reconstruction of networks representing brain dynamics, we show how this approach is superior to other solutions, in that it allows a better characterisation of the parameters space, while requiring a significantly lower computational cost.
Constraint programming for modelling and solving modal satisfiability
Brand, S.; Gennari, R.; de Rijke, M.
2003-01-01
We explore to what extent and how efficiently constraint programmingcan be used in the context of automated reasoning for modal logics. We encode modal satisfiability problems as constraint satisfactionproblems with non-boolean domains, together with suitable constraints.Experiments show that the ap
Constraint programming for modelling and solving modal satisfiability
Brand, S.; Gennari, R.; de Rijke, M.
2003-01-01
We explore to what extent and how efficiently constraint programmingcan be used in the context of automated reasoning for modal logics. We encode modal satisfiability problems as constraint satisfactionproblems with non-boolean domains, together with suitable constraints.Experiments show that the ap
Effective constraint potential in lattice Weinberg - Salam model
Polikarpov, M I
2011-01-01
We investigate lattice Weinberg - Salam model without fermions for the value of the Weinberg angle $\\theta_W \\sim 30^o$, and bare fine structure constant around $\\alpha \\sim 1/150$. We consider the value of the scalar self coupling corresponding to bare Higgs mass around 150 GeV. The effective constraint potential for the zero momentum scalar field is used in order to investigate phenomena existing in the vicinity of the phase transition between the physical Higgs phase and the unphysical symmetric phase of the lattice model. This is the region of the phase diagram, where the continuum physics is to be approached. We compare the above mentioned effective potential (calculated in selected gauges) with the effective potential for the value of the scalar field at a fixed space - time point. We also calculate the renormalized fine structure constant using the correlator of Polyakov lines and compare it with the one - loop perturbative estimate.
New constraints on seismic anisotropy along the Dead Sea transform fault
Kaviani, A.; Rumpker, G.; Asch, G.
2009-12-01
We study seismic anisotropy along the Dead Sea Transform fault (DST) by shear-wave splitting analysis of SKS and SKKS waveforms recorded at a dense network of broad-band and short-period stations of the DESIRE experiment. The DST accommodates the relative motion between Africa and Arabia through a sinistral strike-slip motion. The Dead Sea is a pull-apart basin formed along the DST as a result of stepwise fault-normal displacement. The DESIRE array of stations cover this portion of the DST. We measured the splitting parameters (delay times between the fast and slow components of the shear wave and fast polarization direction) in different period bands. We observed consistent fast polarization directions varying from N14W to N19E at different stations and delay times ranging between 1.0 and 2.5 s. Our preliminary examination reveals that the splitting parameters do not exhibit significant frequency dependence. However, we observe variations in the splitting parameters (mostly delay times) along an E-W profile crossing the DST, with smaller delay times in the middle of the profile, within the surface exposure of the DST shear zone, and with two lobes of relatively large delay times on both sides of the central region. The fast polarization directions along this profile change from a dominant NNW trend in the western side of the DST to a general N-S orientation in the central part and a dominant NNE trend to the east. Waveform modeling is required to infer the lateral and depth variations of the strength and orientation of anisotropy in the crust and upper mantle from these observations. We will also complement our results with the data from the DESERT experiment to provide an overall pattern of seismic anisotropy and structural fabric beneath the DST and surrounding regions from the north of the Dead Sea down to the Red sea.
Culture models of human mammary epithelial cell transformation
Energy Technology Data Exchange (ETDEWEB)
Stampfer, Martha R.; Yaswen, Paul
2000-11-10
Human pre-malignant breast diseases, particularly ductal carcinoma in situ (DCIS)3 already display several of the aberrant phenotypes found in primary breast cancers, including chromosomal abnormalities, telomerase activity, inactivation of the p53 gene and overexpression of some oncogenes. Efforts to model early breast carcinogenesis in human cell cultures have largely involved studies in vitro transformation of normal finite lifespan human mammary epithelial cells (HMEC) to immortality and malignancy. We present a model of HMEC immortal transformation consistent with the know in vivo data. This model includes a recently described, presumably epigenetic process, termed conversion, which occurs in cells that have overcome stringent replicative senescence and are thus able to maintain proliferation with critically short telomeres. The conversion process involves reactivation of telomerase activity, and acquisition of good uniform growth in the absence and presence of TFGB. We propose th at overcoming the proliferative constraints set by senescence, and undergoing conversion, represent key rate-limiting steps in human breast carcinogenesis, and occur during early stage breast cancer progression.
THE CLOWER CONSTRAINTS MODEL DARI SURPLUS ATAU DEFISIT FISKAL PEMERINTAH
Directory of Open Access Journals (Sweden)
Jonni Manurung
2006-01-01
Full Text Available This study has something as a purpose to building the empirical models and the new hypothesis between the broad money, surpluses or fiscal deficit, the general price index or inflation rate, demand for monetary base and demand for bank deposit. This study also head for optimal interest rate for bank deposit at the given value of broad money, surplus or fiscal deficit, general price index, demand for monetary base, and demand for bank deposit. The model build consist to balance central bank, intertemporal budget constraint at the maximum expected utility for hold monetary base and bank deposit. The evaluation of the surplus or fiscal deficit stabilization is with the alteration of the requirement reserve ratio, Gross Domestic Product, general price index and interest rate. The results of the study show that the requirement reserve ratio, Gross Domestic Product, general price index and interest rate is very respect to surplus or deficit fiscal. The contribution requirement reserve ratio and interest rate for surplus or deficit fiscal are relatively high. This results show that the clower constraint model can explain the necessary of fiscal and monetary coordinate. Fiscal policy still weak and cause the real business cycle slow down, high inflation and interest rate. The other hands, monetary policy is very strong and cause fiscal surplus is relatively high. The prudent of government and monetary authority are needed to build the fiscal and monetary policy for create the dynamic economy, lower inflation, requirement reserve ratio and interest rate, and the monetary and fiscal dynamic equilibrium. Abstract in Bahasa Indonesia : Studi ini bertujuan membuat model empiris dan hipotesis baru tentang faktor-faktor broad money, surplus dan defisit fiskal, tingkat bunga secara umum, atau tingkat inflasi, permintaan uang primer dan deposito. Selain itu studi ini juga mencari tingkat suku bunga deposito optimal pada nilai tertentu dari faktor-faktor tersebut
Multiphase Transformer Modelling using Finite Element Method
Directory of Open Access Journals (Sweden)
Nor Azizah Mohd Yusoff
2015-03-01
Full Text Available In the year of 1970 saw the starting invention of the five-phase motor as the milestone in advanced electric motor. Through the years, there are many researchers, which passionately worked towards developing for multiphase drive system. They developed a static transformation system to obtain a multiphase supply from the available three-phase supply. This idea gives an influence for further development in electric machines as an example; an efficient solution for bulk power transfer. This paper highlighted the detail descriptions that lead to five-phase supply with fixed voltage and frequency by using Finite-Element Method (FEM. Identifying of specification on a real transformer had been done before applied into software modeling. Therefore, Finite-Element Method provides clearly understandable in terms of visualize the geometry modeling, connection scheme and output waveform.
New constraints on supergravity models from b --> s$\\gamma$
López, J L; Wang, X; Zichichi, Antonino
1995-01-01
We perform a detailed study of the constraints from b\\to s\\gamma on a large class of supergravity models, including generic four-parameter supergravity models, the minimal SU(5) supergravity model, and SU(5)\\times U(1) supergravity. For each point in the parameter spaces of these models we obtain a range of B(b\\to s\\gamma) values which should conservatively account for the unknown next-to-leading-order QCD corrections. We then classify these points into three categories: ``excluded" points have ranges of B(b\\to s\\gamma) which do not overlap with the experimentally allowed range, ``preferred" points have B(b\\to s\\gamma) ranges which overlap with the Standard Model prediction, and ``Ok" points are neither ``excluded" nor ``preferred" but may become ``excluded" should new CLEO data be consistent with the Standard Model prediction. In {\\em all} cases we observe a strong tendency for the ``preferred" points towards one sign of the Higgs mixing parameter \\mu. For the opposite sign of \\mu there is an upper bound on ...
Electricity market equilibrium model with resource constraint and transmission congestion
Energy Technology Data Exchange (ETDEWEB)
Gao, F. [ABB, Inc., Santa Clara, CA 95050 (United States); Sheble, G.B. [Portland State University, Portland, OR 97207 (United States)
2010-01-15
Electricity market equilibrium model not only helps Independent System Operator/Regulator analyze market performance and market power, but also provides Market Participants the ability to build optimal bidding strategies based on Microeconomics analysis. Supply Function Equilibrium (SFE) is attractive compared to traditional models and many efforts have been made on it before. However, most past research focused on a single-period, single-market model and did not address the fact that GENCOs hold a portfolio of assets in both electricity and fuel markets. This paper first identifies a proper SFE model, which can be applied to a multiple-period situation. Then the paper develops the equilibrium condition using discrete time optimal control considering fuel resource constraints. Finally, the paper discusses the issues of multiple equilibria caused by transmission network and shows that a transmission constrained equilibrium may exist, however the shadow price may not be zero. Additionally, an advantage from the proposed model for merchant transmission planning is discussed. (author)
Sensor Optimization Selection Model Based on Testability Constraint
Institute of Scientific and Technical Information of China (English)
YANG Shuming; QIU Jing; LIU Guanjun
2012-01-01
Sensor selection and optimization is one of the important parts in design for testability.To address the problems that the traditional sensor optimization selection model does not take the requirements of prognostics and health management especially fault prognostics for testability into account and does not consider the impacts of sensor actual attributes on fault detectability,a novel sensor optimization selection model is proposed.Firstly,a universal architecture for sensor selection and optimization is provided.Secondly,a new testability index named fault predictable rate is defined to describe fault prognostics requirements for testability.Thirdly,a sensor selection and optimization model for prognostics and health management is constructed,which takes sensor cost as objective finction and the defined testability indexes as constraint conditions.Due to NP-hard property of the model,a generic algorithm is designed to obtain the optimal solution.At last,a case study is presented to demonstrate the sensor selection approach for a stable tracking servo platform.The application results and comparison analysis show the proposed model and algorithm are effective and feasible.This approach can be used to select sensors for prognostics and health management of any system.
Observational Constraints on Models of Rapidly Evolving Luminous Stars
Rosenfield, Philip; Dalcanton, Julianne; Bressan, Alessandro; Girardi, Leo; Marigo, Paola; Angst Team
2015-01-01
Resolved stellar populations in galaxies are excellent laboratories for testing our understanding of galaxy formation, integrated colors and luminosities, supernova progenitor masses, and energy input from stellar feedback. However, the usefulness of resolved stellar populations rests on the ability to accurately model the evolution of the underlying stars. Part of my thesis work is focused on two uncertain phases of stellar evolution; the luminous core helium burning (HeB) phase and the thermally pulsating AGB (TP-AGB) phase. Dwarf galaxies, imaged as part of the ACS Nearby Galaxy Survey Treasury and its HST/NIR follow-up campaign, provide ideal testing grounds for new models because the galaxies span ~2 dex in metallicity, many have significant HeB populations (i.e, the HeB sequence is populated with stars with masses from ~2-15 Msun), and many contain large numbers of TP-AGB stars. I will present how I used ANGST to constrain low metallicity stellar evolution models with the Padova-Trieste Stellar Evolution Code (PARSEC; the recently updated Padova Stellar Evolution Library) and COLIBRI (a new tool for modeling TP-AGB stars). Specifically, I will show how increasing the strength of core overshooting with increasing mass in HeB stars improves data and model agreement. I will also present constraints to the mass loss prescriptions of low mass, low metallicity TP-AGB stars.
Model-independent constraints on the cosmic opacity
Energy Technology Data Exchange (ETDEWEB)
Holanda, R.F.L. [Departamento de Física, Universidade Estadual da Paraíba, 58429-500, Campina Grande - PB (Brazil); Carvalho, J.C.; Alcaniz, J.S., E-mail: holanda@uepb.edu.br, E-mail: carvalho@dfte.ufrn.br, E-mail: alcaniz@on.br [Departamento de Astronomia, Observatório Nacional, 20921-400, Rio de Janeiro - RJ (Brazil)
2013-04-01
We use current measurements of the expansion rate H(z) and cosmic background radiation bounds on the spatial curvature of the Universe to impose cosmological model-independent constraints on cosmic opacity. To perform our analyses, we compare opacity-free distance modulus from H(z) data with those from two type Ia supernovae compilations, namely, the Union2.1 plus the most distant spectroscopically confirmed SNe Ia (SCP-0401 at z = 1.713) and two Sloan Digital Sky Survey (SDSS) subsamples. We find that a completely transparent universe is in full agreement with the Union 2.1 + SNe Ia SCP-0401 sample. For the SDSS compilations, such universe is compatible with observations at < 1.5σ level regardless the SNe Ia light-curve fitting used.
Universal Constraints on Low-Energy Flavour Models
Calibbi, Lorenzo; Pokorski, Stefan; Ziegler, Robert
2012-01-01
It is pointed out that in a general class of flavour models one can identify certain universally present FCNC operators, induced by the exchange of heavy flavour messengers. Their coefficients depend on the rotation angles that connect flavour and fermion mass basis. The lower bounds on the messenger scale are derived using updated experimental constraints on the FCNC operators. The obtained bounds are different for different operators and in addition they depend on the chosen set of rotations. Given the sensitivity expected in the forthcoming experiments, the present analysis suggests interesting room for discovering new physics. As the highlights emerge the leptonic processes, $\\mu\\rightarrow e\\gamma$, $\\mu\\rightarrow eee$ and $\\mu\\rightarrow e$ conversion in nuclei.
Institute of Scientific and Technical Information of China (English)
Wang Yafei; Huang Xiaojun
2007-01-01
Over the past 20 years, China has made spectacular achievements in economic growth as well as in the transformation of economic growth pattern. Industrial structure is being updated, and technology is playing a more and more important role in economic development. The energy and resource consumption in many industries and enterprises are reducing. However, we should realize that there are still many problems in changing the economic growth pattern,such as high input, high consumption, high discharge, inharmony, recycling difficulty, and low efficiency, which have greatly impaired and restrict Chinese economic development. Therefore, the fundamental change of the economic growth pattern is inevitable. Based on the analysis on the status quo and the exploit of resources, this paper suggests that the transformation from unsustainable to sustainable growth is the only choice in changing the economic growth pattern. In addition, the transformation should not completely rely on the fundamental effects of market mechanism. We should make full use of the power of governments to speed up the transformation of economic system.
Indirect constraints on the Georgi-Machacek model and implications for Higgs couplings
Hartling, Katy; Logan, Heather E
2014-01-01
We update the indirect constraints on the Georgi-Machacek model from $B$-physics and electroweak precision observables, including new constraints from $b \\to s \\gamma$ and $B^0_s \\to \\mu^+ \\mu^-$. We illustrate the effect of these constraints on the couplings of the Standard Model-like Higgs boson by performing scans using the most general scalar potential, subject to vacuum stability and perturbativity constraints. We find that simultaneous enhancements of all the Higgs production cross sections by up to 39\\% are still allowed after imposing these constraints. LHC rate measurements on the Higgs pole could be blind to these enhancements if unobserved non-standard Higgs decays are present.
Constraints on surface evapotranspiration: implications for modeling and observations
Gentine, P.
2015-12-01
The continental hydrological cycle and especially evapotranspiration are constrained by additional factors such as the energy availability and the carbon cycle. As a results trying to understand and predict the surface hydrologic cycle in isolation might be highly unreliable. We present two examples were constraints induced by 1) radiation control through cloud albedo feedback and 2) carbon control on the surface water use efficiency are essential to correctly predict the seasonal hydrologic cycle. In the first example we show that correctly modeling diurnal and seasonal convection and the associated cloud-albedo feedback (through land-atmosphere and convection-large-scale circulation feedbacks) is essential to correctly model the surface hydrologic cycle in the Amazon, and to correct biases observed in all general circulation models. This calls for improved modeling of convection to correctly predict the tropical continental hydrologic cycle.In the second example we show that typical drought index based only on energy want water availability misses vegetation physiological and carbon feedback and cannot correctly represent the seasonal cycle of soil moisture stress. The typical Palmer Drought Stress Index is shown to be incapable of rejecting water stress in the future. This calls for new drought assessment metrics that may include vegetation and carbon feedback.
Coaching Model + Clinical Playbook = Transformative Learning.
Fletcher, Katherine A; Meyer, Mary
2016-01-01
Health care employers demand that workers be skilled in clinical reasoning, able to work within complex interprofessional teams to provide safe, quality patient-centered care in a complex evolving system. To this end, there have been calls for radical transformation of nursing education including the development of a baccalaureate generalist nurse. Based on recommendations from the American Association of Colleges of Nursing, faculty concluded that clinical education must change moving beyond direct patient care by applying the concepts associated with designer, manager, and coordinator of care and being a member of a profession. To accomplish this, the faculty utilized a system of focused learning assignments (FLAs) that present transformative learning opportunities that expose students to "disorienting dilemmas," alternative perspectives, and repeated opportunities to reflect and challenge their own beliefs. The FLAs collected in a "Playbook" were scaffolded to build the student's competencies over the course of the clinical experience. The FLAs were centered on the 6 Quality and Safety Education for Nurses competencies, with 2 additional concepts of professionalism and systems-based practice. The FLAs were competency-based exercises that students performed when not assigned to direct patient care or had free clinical time. Each FLA had a lesson plan that allowed the student and faculty member to see the competency addressed by the lesson, resources, time on task, student instructions, guide for reflection, grading rubric, and recommendations for clinical instructor. The major advantages of the model included (a) consistent implementation of structured learning experiences by a diverse teaching staff using a coaching model of instruction; (b) more systematic approach to present learning activities that build upon each other; (c) increased time for faculty to interact with students providing direct patient care; (d) guaranteed capture of selected transformative
Erickson, Timmons M.; Pearce, Mark A.; Reddy, Steven M.; Timms, Nicholas E.; Cavosie, Aaron J.; Bourdet, Julien; Rickard, William D. A.; Nemchin, Alexander A.
2017-01-01
Zircon (ZrSiO4) is used to study impact structures because it responds to shock loading and unloading in unique, crystallographically controlled manners. One such phenomenon is the transformation of zircon to the high-pressure polymorph, reidite. This study quantifies the geometric and crystallographic orientation relationships between these two phases using naturally shocked zircon grains. Reidite has been characterized in 32 shocked zircon grains (shocked to stages II and III) using a combination of electron backscatter diffraction (EBSD) and focused ion beam cross-sectional imaging techniques. The zircon-bearing clasts were obtained from within suevite breccia from the Nördlingen 1973 borehole, close to the center of the 14.4 Ma Ries impact crater, in Bavaria, Germany. We have determined that multiple sets (up to 4) of reidite lamellae can form in a variety of non-rational habit planes within the parent zircon. However, EBSD mapping demonstrates that all occurrences of lamellar reidite have a consistent interphase misorientation relationship with the host zircon that is characterized by an approximate alignment of a {100}zircon with a {112}reidite and alignment of a {112}zircon with a conjugate {112}reidite. Given the tetragonal symmetry of zircon and reidite, we predict that there are eight possible variants of this interphase relationship for reidite transformation within a single zircon grain. Furthermore, laser Raman mapping of one reidite-bearing grain shows that moderate metamictization can inhibit reidite formation, thereby highlighting that the transformation is controlled by zircon crystallinity. In addition to lamellar reidite, submicrometer-scale granules of reidite were observed in one zircon. The majority of reidite granules have a topotaxial alignment that is similar to the lamellar reidite, with some additional orientation dispersion. We confirm that lamellar reidite likely forms via a deviatoric transformation mechanism in highly crystalline
DEFF Research Database (Denmark)
Greenyer, Joel; Kindler, Ekkart
2010-01-01
The Model Driven Architecture (MDA) is an approach to develop software based on different models. There are separate models for the business logic and for platform specific details. Moreover, code can be generated automatically from these models. This makes transformations a core technology for MDA...... and for model-based software engineering approaches in general. QVT (Query/View/Transformation) is the transformation technology recently proposed for this purpose by the OMG. TGGs (Triple Graph Grammars) are another transformation technology proposed in the mid-nineties, used for example in the FUJABA CASE...... tool. In contrast to many other transformation technologies, both QVT and TGGs declaratively define the relation between two models. With this definition, a transformation engine can execute a transformation in either direction and, based on the same definition, can also propagate changes from one...
TRANSFORM - TRANsient Simulation Framework of Reconfigurable Models
Energy Technology Data Exchange (ETDEWEB)
2017-09-01
Existing development tools for early stage design and scoping of energy systems are often time consuming to use, proprietary, and do not contain the necessary function to model complete systems (i.e., controls, primary, and secondary systems) in a common platform. The Modelica programming language based TRANSFORM tool (1) provides a standardized, common simulation environment for early design of energy systems (i.e., power plants), (2) provides a library of baseline component modules to be assembled into full plant models using available geometry, design, and thermal-hydraulic data, (3) defines modeling conventions for interconnecting component models, and (4) establishes user interfaces and support tools to facilitate simulation development (i.e., configuration and parameterization), execution, and results display and capture.
Weber, Arthur L.; Fonda, Mark (Technical Monitor)
2001-01-01
The thermodynamics of organic chemistry under mild aqueous conditions was examined in order to begin to understand its influence on the structure and operation of metabolism and its antecedents. Free energies were estimated for four types reactions of biochemical importance carbon-carbon bond cleavage and synthesis, hydrogen transfer between carbon groups, dehydration of alcohol groups, and aldo-keto isomerization. The energies were calculated for mainly aliphatic groups composed of carbon, hydrogen, and oxygen. The energy values showed that (1) when carbon-carbon bond cleavage involves two different types of functional groups, transfer of the shared electron-pair to the more reduced carbon group is energetically favored over transfer to the more oxidized carbon group, and (2) the energy of carbon-carbon bond transformation is strongly dependent on the type of functional group that donates the shared electron-pair during cleavage, and the group that accepts the shared electron-pair during synthesis, and (3) the energetics of C-C bond transformation is determined primarily by the half-reaction energies of the couples: carbonyl/carboxylic acid, carboxylic acid/carbon dioxide, alcohol/carbonyl, and hydrocarbon/alcohol. The energy of hydrogen-transfer between carbon groups was found to depend on the functional group class of both the hydrogen-donor and hydrogen-acceptor. From these and other observations we concluded that the chemistry of the origin of metabolism (and to a lesser degree modem metabolism) is strongly constrained by the (1) limited disproportionation energy of organic substrates that can be dissipated in a few irreversible reactions, (2) the energy-dominance of few half-reaction couples in carbon-carbon bond transformation that establishes whether a chemical reaction is energetically irreversible, reversible or unfeasible, and (3) the dependence of the transformation-energy on the oxidation state of carbon groups (functional group type) which is
Genome-scale constraint-based modeling of Geobacter metallireducens
Directory of Open Access Journals (Sweden)
Famili Iman
2009-01-01
Full Text Available Abstract Background Geobacter metallireducens was the first organism that can be grown in pure culture to completely oxidize organic compounds with Fe(III oxide serving as electron acceptor. Geobacter species, including G. sulfurreducens and G. metallireducens, are used for bioremediation and electricity generation from waste organic matter and renewable biomass. The constraint-based modeling approach enables the development of genome-scale in silico models that can predict the behavior of complex biological systems and their responses to the environments. Such a modeling approach was applied to provide physiological and ecological insights on the metabolism of G. metallireducens. Results The genome-scale metabolic model of G. metallireducens was constructed to include 747 genes and 697 reactions. Compared to the G. sulfurreducens model, the G. metallireducens metabolic model contains 118 unique reactions that reflect many of G. metallireducens' specific metabolic capabilities. Detailed examination of the G. metallireducens model suggests that its central metabolism contains several energy-inefficient reactions that are not present in the G. sulfurreducens model. Experimental biomass yield of G. metallireducens growing on pyruvate was lower than the predicted optimal biomass yield. Microarray data of G. metallireducens growing with benzoate and acetate indicated that genes encoding these energy-inefficient reactions were up-regulated by benzoate. These results suggested that the energy-inefficient reactions were likely turned off during G. metallireducens growth with acetate for optimal biomass yield, but were up-regulated during growth with complex electron donors such as benzoate for rapid energy generation. Furthermore, several computational modeling approaches were applied to accelerate G. metallireducens research. For example, growth of G. metallireducens with different electron donors and electron acceptors were studied using the genome
Constraints on the parameters of the Left Right Mirror Model
Cerón, V E; Díaz-Cruz, J L; Maya, M; Ceron, Victoria E.; Cotti, Umberto; Maya, Mario
1998-01-01
We study some phenomenological constraints on the parameters of a left right model with mirror fermions (LRMM) that solves the strong CP problem. In particular, we evaluate the contribution of mirror neutrinos to the invisible Z decay width (\\Gamma_Z^{inv}), and we find that the present experimental value on \\Gamma_Z^{inv}, can be used to place an upper bound on the Z-Z' mixing angle that is consistent with limits obtained previously from other low-energy observables. In this model the charged fermions that correspond to the standard model (SM) mix with its mirror counterparts. This mixing, simultaneously with the Z-Z' one, leads to modifications of the \\Gamma(Z --> f \\bar{f}) decay width. By comparing with LEP data, we obtain bounds on the standard-mirror lepton mixing angles. We also find that the bottom quark mixing parameters can be chosen to fit the experimental values of R_b, and the resulting values for the Z-Z' mixing angle do not agree with previous bounds. However, this disagreement disappears if on...
Concurrent Constraint Programming: A Language and Its Execution Model
Institute of Scientific and Technical Information of China (English)
廖乐健; 曹元大
2003-01-01
To overcome inefficiency in traditional logic programming, a declarative programming language COPS is designed based on the notion of concurrent constraint programming (CCP). The improvement is achieved by the adoption of constraint-based heuristic strategy and the introduction of deterministic components in the framework of CCP. Syntax specification and an operational semantic description are presented.
Iterated non-linear model predictive control based on tubes and contractive constraints.
Murillo, M; Sánchez, G; Giovanini, L
2016-05-01
This paper presents a predictive control algorithm for non-linear systems based on successive linearizations of the non-linear dynamic around a given trajectory. A linear time varying model is obtained and the non-convex constrained optimization problem is transformed into a sequence of locally convex ones. The robustness of the proposed algorithm is addressed adding a convex contractive constraint. To account for linearization errors and to obtain more accurate results an inner iteration loop is added to the algorithm. A simple methodology to obtain an outer bounding-tube for state trajectories is also presented. The convergence of the iterative process and the stability of the closed-loop system are analyzed. The simulation results show the effectiveness of the proposed algorithm in controlling a quadcopter type unmanned aerial vehicle.
Fleishman, Greg M.; Gutman, Boris A.; Fletcher, P. Thomas; Thompson, Paul
2015-03-01
Patients with Alzheimer's disease and other brain disorders often show a similar spatial distribution of volume change throughout the brain over time, but this information is not yet used in registration algorithms to refine the quantification of change. Here, we develop a mathematical basis to incorporate that prior information into a longitudinal structural neuroimaging study. We modify the canonical minimization problem for non-linear registration to include a term that couples a collection of registrations together to enforce group similarity. More specifically, throughout the computation we maintain a group-level representation of the transformations and constrain updates to individual transformations to be similar to this representation. The derivations necessary to produce the Euler-Lagrange equations for the coupling term are presented and a gradient descent algorithm based on the formulation was implemented. We demonstrate using 57 longitudinal image pairs from the Alzheimer's Disease Neuroimaging Initiative (ADNI) that longitudinal registration with such a groupwise coupling prior is more robust to noise in estimating change, suggesting such change maps may have several important applications.
An Efficient Constraint Boundary Sampling Method for Sequential RBDO Using Kriging Surrogate Model
Energy Technology Data Exchange (ETDEWEB)
Kim, Jihoon; Jang, Junyong; Kim, Shinyu; Lee, Tae Hee [Hanyang Univ., Seoul (Korea, Republic of); Cho, Sugil; Kim, Hyung Woo; Hong, Sup [Korea Research Institute of Ships and Ocean Engineering, Busan (Korea, Republic of)
2016-06-15
Reliability-based design optimization (RBDO) requires a high computational cost owing to its reliability analysis. A surrogate model is introduced to reduce the computational cost in RBDO. The accuracy of the reliability depends on the accuracy of the surrogate model of constraint boundaries in the surrogated-model-based RBDO. In earlier researches, constraint boundary sampling (CBS) was proposed to approximate accurately the boundaries of constraints by locating sample points on the boundaries of constraints. However, because CBS uses sample points on all constraint boundaries, it creates superfluous sample points. In this paper, efficient constraint boundary sampling (ECBS) is proposed to enhance the efficiency of CBS. ECBS uses the statistical information of a kriging surrogate model to locate sample points on or near the RBDO solution. The efficiency of ECBS is verified by mathematical examples.
Laplace transform in tracer kinetic modeling
Energy Technology Data Exchange (ETDEWEB)
Hauser, Eliete B., E-mail: eliete@pucrs.br [Instituto do Cerebro (InsCer/FAMAT/PUC-RS), Porto Alegre, RS, (Brazil). Faculdade de Matematica
2013-07-01
The main objective this paper is to quantify the pharmacokinetic processes: absorption, distribution and elimination of radiopharmaceutical(tracer), using Laplace transform method. When the drug is administered intravenously absorption is complete and is available in the bloodstream to be distributed throughout the whole body in all tissues and fluids, and to be eliminated. Mathematical modeling seeks to describe the processes of distribution and elimination through compartments, where distinct pools of tracer (spatial location or chemical state) are assigned to different compartments. A compartment model is described by a system of differential equations, where each equation represents the sum of all the transfer rates to and from a specific compartment. In this work a two-tissue irreversible compartment model is used for description of tracer, [{sup 18}F]2-fluor-2deoxy-D-glucose. In order to determine the parameters of the model, it is necessary to have information about the tracer delivery in the form of an input function representing the time-course of tracer concentration in arterial blood or plasma. We estimate the arterial input function in two stages and apply the Levenberg-Marquardt Method to solve nonlinear regressions. The transport of FDG across de arterial blood is very fast in the first ten minutes and then decreases slowly. We use de Heaviside function to represent this situation and this is the main contribution of this study. We apply the Laplace transform and the analytical solution for two-tissue irreversible compartment model is obtained. The only approach is to determinate de arterial input function. (author)
An Intelligent Response Surface Methodology for Modeling of Domain Level Constraints
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
An effective modeling method of domain level constraints in the constraint network for concurrent engineering (CE) was developed. The domain level constraints were analyzed and the framework of modeling of domain level constraints based on simulation and approximate technology was given. An intelligent response surface methodology (IRSM) was proposed, in which artificial intelligence technologies are introduced into the optimization process. The design of crank and connecting rod in the V6 engine as example was given to show the validity of the modeling method.
Zhu, Lin; Ma, Hongru
2015-01-01
We introduce a methodology to design high efficient wireless power transfer(WPT) devices inspired by transformation optics theory, and calculate its transmission power and efficiency by the scattering theory for electromagnetic (EM) wave. Using the series expansion methods, we demonstrate the WPT devices' transmission efficiency can be significantly improved by covered with super scatterer. The comparison with those results obtained by COMSOL shows the series expansion method is effective and expected to deal with long-distance transfer problem. We present some examples to exam our methodology, and showed how WPT devices' efficiency is significantly improved as our expectation. The transfer distances of such WPT devices are several meters and can be widely extended by regulating its parameters.
Minimal models from W-constrained hierarchies via the Kontsevich-Miwa transform
Gato-Rivera, Beatriz
1992-01-01
A direct relation between the conformal formalism for 2d-quantum gravity and the W-constrained KP hierarchy is found, without the need to invoke intermediate matrix model technology. The Kontsevich-Miwa transform of the KP hierarchy is used to establish an identification between W constraints on the KP tau function and decoupling equations corresponding to Virasoro null vectors. The Kontsevich-Miwa transform maps the $W^{(l)}$-constrained KP hierarchy to the $(p^\\prime,p)$ minimal model, with the tau function being given by the correlator of a product of (dressed) $(l,1)$ (or $(1,l)$) operators, provided the Miwa parameter $n_i$ and the free parameter (an abstract $bc$ spin) present in the constraints are expressed through the ratio $p^\\prime/p$ and the level $l$.
VMTL: a language for end-user model transformation
DEFF Research Database (Denmark)
Acretoaie, Vlad; Störrle, Harald; Strüber, Daniel
2016-01-01
, these languages are largely ill-equipped for adoption by end-user modelers in areas such as requirements engineering, business process management, or enterprise architecture. We aim to introduce a model transformation language addressing the skills and requirements of end-user modelers. With this contribution, we......Model transformation is a key enabling technology of Model-Driven Engineering (MDE). Existing model transformation languages are shaped by and for MDE practitioners—a user group with needs and capabilities which are not necessarily characteristic of modelers in general. Consequently...... hope to broaden the application scope of model transformation and MDE technology in general. We discuss the profile of end-user modelers and propose a set of design guidelines for model transformation languages addressing them. We then introduce Visual Model Transformation Language (VMTL) following...
Systematic assignment of thermodynamic constraints in metabolic network models
Directory of Open Access Journals (Sweden)
Heinemann Matthias
2006-11-01
Full Text Available Abstract Background The availability of genome sequences for many organisms enabled the reconstruction of several genome-scale metabolic network models. Currently, significant efforts are put into the automated reconstruction of such models. For this, several computational tools have been developed that particularly assist in identifying and compiling the organism-specific lists of metabolic reactions. In contrast, the last step of the model reconstruction process, which is the definition of the thermodynamic constraints in terms of reaction directionalities, still needs to be done manually. No computational method exists that allows for an automated and systematic assignment of reaction directions in genome-scale models. Results We present an algorithm that – based on thermodynamics, network topology and heuristic rules – automatically assigns reaction directions in metabolic models such that the reaction network is thermodynamically feasible with respect to the production of energy equivalents. It first exploits all available experimentally derived Gibbs energies of formation to identify irreversible reactions. As these thermodynamic data are not available for all metabolites, in a next step, further reaction directions are assigned on the basis of network topology considerations and thermodynamics-based heuristic rules. Briefly, the algorithm identifies reaction subsets from the metabolic network that are able to convert low-energy co-substrates into their high-energy counterparts and thus net produce energy. Our algorithm aims at disabling such thermodynamically infeasible cyclic operation of reaction subnetworks by assigning reaction directions based on a set of thermodynamics-derived heuristic rules. We demonstrate our algorithm on a genome-scale metabolic model of E. coli. The introduced systematic direction assignment yielded 130 irreversible reactions (out of 920 total reactions, which corresponds to about 70% of all irreversible
Energy Technology Data Exchange (ETDEWEB)
Barton, N R; Benson, D J; Becker, R; Bykov, Y; Caplan, M
2004-10-18
We present a crystal level model for thermo-mechanical deformation with phase transformation capabilities. The model is formulated to allow for large pressures (on the order of the elastic moduli) and makes use of a multiplicative decomposition of the deformation gradient. Elastic and thermal lattice distortions are combined into a single lattice stretch to allow the model to be used in conjunction with general equation of state relationships. Phase transformations change the mass fractions of the material constituents. The driving force for phase transformations includes terms arising from mechanical work, from the temperature dependent chemical free energy change on transformation, and from interaction energy among the constituents. Deformation results from both these phase transformations and elasto-viscoplastic deformation of the constituents themselves. Simulation results are given for the {alpha} to {epsilon} phase transformation in iron. Results include simulations of shock induced transformation in single crystals and of compression of polycrystals. Results are compared to available experimental data.
Constraints on Planetesimal Collision Models in Debris Disks
MacGregor, Meredith A; Chandler, Claire; Ricci, Luca; Maddison, Sarah T; Cranmer, Steven R; Andrews, Sean M; Hughes, A Meredith; Steele, Amy
2016-01-01
Observations of debris disks offer a window into the physical and dynamical properties of planetesimals in extrasolar systems through the size distribution of dust grains. In particular, the millimeter spectral index of thermal dust emission encodes information on the grain size distribution. We have made new VLA observations of a sample of seven nearby debris disks at 9 mm, with 3" resolution and $\\sim5$ $\\mu$Jy/beam rms. We combine these with archival ATCA observations of eight additional debris disks observed at 7 mm, together with up-to-date observations of all disks at (sub)millimeter wavelengths from the literature to place tight constraints on the millimeter spectral indices and thus grain size distributions. The analysis gives a weighted mean for the slope of the power law grain size distribution, $n(a)\\propto a^{-q}$, of $\\langle q \\rangle = 3.36\\pm0.02$, with a possible trend of decreasing $q$ for later spectral type stars. We compare our results to a range of theoretical models of collisional casca...
The Distributed Network Monitoring Model with Bounded Delay Constraints
Institute of Scientific and Technical Information of China (English)
LIU Xiang-hui; YIN Jian-ping; LU Xi-cheng; CAI Zhi-ping; ZHAO Jian-min
2004-01-01
We address the problem of optimizing a distributed monitoring system and the goal of the optimization is to reduce the cost of deployment of the monitoring infrastructure by identifying a minimum aggregating set subject to delay constraint on the aggregating path. We show that this problem is NP-hard and propose approximation algorithm proving the approximation ratio with ln m+1, where is the number of monitoring nodes. At last we extend our modal with more constraint of bounded delay variation.
Sum Rule Constraints and the Quality of Approximate Kubo-Transformed Correlation Functions.
Hernández de la Peña, Lisandro
2016-02-11
In this work, a general protocol for evaluating the quality of approximate Kubo correlation functions of nontrivial systems in many dimensions is discussed. We first note that the generalized deconvolution of the Kubo transformed correlation function onto a time correlation function at a given value τ in imaginary time, such that 0 function and whose iterative extension allows us to link derivatives of different order in the corresponding correlation functions. We focus on the case when τ = βℏ/2, for which all deconvolution kernels become real valued functions and their asymptotic behavior at long times exhibits a polynomial divergence. It is then shown that thermally symmetrized static averages, and the averages of the corresponding time derivatives, are ideally suited to investigate the quality of approximate Kubo correlation functions at successively larger (and up to arbitrarily long) times. This overall strategy is illustrated analytically for a harmonic system and numerically for a multidimensional double-well potential and a Lennard-Jones fluid. The analysis includes an assessment of RPMD position autocorrelation results as a function of the number of dimensions in a double-well potential and of the RPMD velocity autocorrelation function of liquid neon at 30 K.
A structure-based model of semantic integrity constraints for relational data bases
Rasdorf, William J.; Ulberg, Karen J.; Baugh, John W., Jr.
1987-01-01
Data base management systems (DBMSs) are in widespread use because of the ease and flexibility with which users access large volumes of data. Ensuring data accuracy through integrity constraints is a central aspect of DBMS use. However, many DBMSs still lack adequate integrity support. In additon, a comprehensive theoretical basis for such support the role of a constraint classification system - has yet to be developed. This paper presents a formalism that classifies semantic integrity constraints based on the structure of the relational model. Integrity constraints are characterized by the portion of the data base structure they access, whether one or more relations, attributes, or tuples. Thus, the model is completely general, allowing the arbitrary specification of any constraint. Examples of each type of constraint are illustrated using a small engineering data base, and various implementation issues are discussed.
Test-driven verification/validation of model transformations
Institute of Scientific and Technical Information of China (English)
László LENGYEL; Hassan CHARAF
2015-01-01
Why is it important to verify/validate model transformations? The motivation is to improve the quality of the trans-formations, and therefore the quality of the generated software artifacts. Verified/validated model transformations make it possible to ensure certain properties of the generated software artifacts. In this way, verification/validation methods can guarantee different requirements stated by the actual domain against the generated/modified/optimized software products. For example, a verified/ validated model transformation can ensure the preservation of certain properties during the model-to-model transformation. This paper emphasizes the necessity of methods that make model transformation verified/validated, discusses the different scenarios of model transformation verification and validation, and introduces the principles of a novel test-driven method for verifying/ validating model transformations. We provide a solution that makes it possible to automatically generate test input models for model transformations. Furthermore, we collect and discuss the actual open issues in the field of verification/validation of model transformations.
T:XML: A Tool Supporting User Interface Model Transformation
López-Jaquero, Víctor; Montero, Francisco; González, Pascual
Model driven development of user interfaces is based on the transformation of an abstract specification into the final user interface the user will interact with. The design of transformation rules to carry out this transformation process is a key issue in any model-driven user interface development approach. In this paper, we introduce T:XML, an integrated development environment for managing, creating and previewing transformation rules. The tool supports the specification of transformation rules by using a graphical notation that works on the basis of the transformation of the input model into a graph-based representation. T:XML allows the design and execution of transformation rules in an integrated development environment. Furthermore, the designer can also preview how the generated user interface looks like after the transformations have been applied. These previewing capabilities can be used to quickly create prototypes to discuss with the users in user-centered design methods.
Decision Model for Life Cycle Assessment of Power Transformer during Load Violation
Directory of Open Access Journals (Sweden)
S. S. Bhandari
2010-05-01
Full Text Available Utility have normally planned the power transformer based on its designed load demand for the long term. Due to unexpected penetration, the actual load profile does not always follow the designed load and load violation will occur at some points during the life cycle of the power transformer for which the utility is inevitably required to make strategic decision. In the past, the decisions were mainly focused on the technical condition of the assetwithout any consideration to investment budget limitation. In this paper, an alternative methodology comprising of knowledge based model, financial model and decision criteria is proposed to make an optimal decision during load violation. A generic power system similar to Nepal Electricity Authority’s context was utilized as a case study. The result depicts that this model can effectively assess the life cycle of power transformer balancing both the financialand technical constraints.
F-Alloy: An Alloy Based Model Transformation Language
Gammaitoni, Loïc; Kelsen, Pierre
2015-01-01
Model transformations are one of the core artifacts of a model-driven engineering approach. The relational logic language Alloy has been used in the past to verify properties of model transformations. In this paper we introduce the concept of functional Alloy modules. In essence a functional Alloy module can be viewed as an Alloy module representing a model transformation. We describe a sublanguage of Alloy called F-Alloy that allows the specification of functional Alloy modules. Module...
Institute of Scientific and Technical Information of China (English)
王宇红; 黄德先; 金以慧
2005-01-01
A hybrid approach using MLD (mixed logical dynamical) framework to handle infeasibility and constraint prioritization issues in MPC (model predictive control) based on input-output model is introduced. By expressing constraint priorities as propositional logics and by transforming the propositional logics into inequalities,the infeasibility and constraint prioritization issues are solved in the MPC. Constraints with higher priorities are met first, and then these with lower priorities are satisfied as much as possible. This new approach is illustrated in the control of a heavy oil fractionator-Shell column. The overall control performance has been significantly improved through the infeasibility and control priorities handling.
Constraint Specialisation in Horn Clause Verification
DEFF Research Database (Denmark)
Kafle, Bishoksan; Gallagher, John Patrick
2015-01-01
We present a method for specialising the constraints in constrained Horn clauses with respect to a goal. We use abstract interpretation to compute a model of a query-answer transformation of a given set of clauses and a goal. The effect is to propagate the constraints from the goal top......-down and propagate answer constraints bottom-up. Our approach does not unfold the clauses at all; we use the constraints from the model to compute a specialised version of each clause in the program. The approach is independent of the abstract domain and the constraints theory underlying the clauses. Experimental...
Consistency maintenance for constraint in role-based access control model
Institute of Scientific and Technical Information of China (English)
韩伟力; 陈刚; 尹建伟; 董金祥
2002-01-01
Constraint is an important aspect of role-based access control and is sometimes argued to be the principal motivation for role-based access control (RBAC). But so far'few authors have discussed consistency maintenance for constraint in RBAC model. Based on researches of constraints among roles and types of inconsistency among constraints, this paper introduces correaponding formal rules, rulebased reasoning and corresponding methods to detect, avoid and resolve these inconsistencies. Finally,the paper introduces briefly the application of consistency maintenance in ZD-PDM, an enterprise-ori-ented product data management (PDM) system.
Consistency maintenance for constraint in role-based access control model
Institute of Scientific and Technical Information of China (English)
韩伟力; 陈刚; 尹建伟; 董金祥
2002-01-01
Constraint is an important aspect of role-based access control and is sometimes argued to be the principal motivation for role-based access control (RBAC). But so far few authors have discussed consistency maintenance for constraint in RBAC model. Based on researches of constraints among roles and types of inconsistency among constraints, this paper introduces corresponding formal rules, rule-based reasoning and corresponding methods to detect, avoid and resolve these inconsistencies. Finally, the paper introduces briefly the application of consistency maintenance in ZD-PDM, an enterprise-oriented product data management (PDM) system.
Controlling reuse in pattern-based model-to-model transformations
Guerra, Esther,; De Lara, Juan,; Orejas, Fernando
2010-01-01
Model-to-model transformation is a central activity in Model-Driven Engineering that consists of transforming models from a source to a target language. Pattern-based model-to-model transformation is our approach for specifying transformations in a declarative, relational and formal style. The approach relies on patterns describing allowed or forbidden relations between two models. These patterns are compiled into operational mechanisms to perform forward and backward transformations. Inspire...
DEFF Research Database (Denmark)
Mödersheim, Sebastian Alexander; Basin, David; Viganò, Luca
2010-01-01
, under the assumption that the original constraint-based approach has these properties. Practically, as a concrete case study, we have integrated this technique into OFMC, a state-of-the-art model-checker for security protocol analysis, and demonstrated its effectiveness by extensive experimentation. Our......We introduce constraint differentiation, a powerful technique for reducing search when model-checking security protocols using constraint-based methods. Constraint differentiation works by eliminating certain kinds of redundancies that arise in the search space when using constraints to represent...
A hybrid Scatter/Transform cloaking model
Directory of Open Access Journals (Sweden)
Gad Licht
2015-01-01
Full Text Available A new Scatter/Transform cloak is developed that combines the light bending of refraction characteristic of a Transform cloak with the scatter cancellation characteristic of a Scatter cloak. The hybrid cloak incorporates both Transform’s variable index of refraction with modified linear intrusions to maximize the Scatter cloak effect. Scatter/Transform improved the scattering cross-section of cloaking in a 2-dimensional space to 51.7% compared to only 39.6% or 45.1% respectively with either Scatter or Transform alone. Metamaterials developed with characteristics based on the new ST hybrid cloak will exhibit superior cloaking capabilities.
Performance in model transformations: experiments with ATL and QVT
van Amstel, Marcel; Bosems, S.; Ivanov, Ivan; Ferreira Pires, Luis; Cabot, Jordi; Visser, Eelco
Model transformations are increasingly being incorporated in software development processes. However, as systems being developed with transformations grow in size and complexity, the performance of the transformations tends to degrade. In this paper we investigate the factors that have an impact on
$b \\rightarrow s \\gamma$ and $\\epsilon_b$ Constraints on Two Higgs Doublet Model
Park, G T
1994-01-01
We perform a combined analysis of two stringent constraints on the 2 Higgs doublet model, one coming from the recently announced CLEO II bound on $B(b \\rightarrow s \\gamma)$ and the other from the recent LEP data on $\\epsilon_b$. We have included one-loop vertex corrections to $Z \\rightarrow b \\overline b$ through $\\epsilon_b$ in the model. We find that the new $\\epsilon_b$ constraint excludes most of the less appealing window $\\tan\\beta\\lsim 1$ at $90\\%$C.~L. for $m_t=150\\GeV$. We also find that although $b \\rightarrow s \\gamma$ constraint is stronger for $\\tan\\beta>1$, $\\epsilon_b$ constraint is stronger for $\\tan\\beta\\lsim 1$, and therefore these two are the strongest and complimentary constraints present in the charged Higgs sector of the model.
On the Computational Expressiveness of Model Transformation Languages
DEFF Research Database (Denmark)
Al-Sibahi, Ahmad Salim
2015-01-01
Common folklore in the model transformation community dictates that most transformation languages are Turing-complete. It is however seldom that a proof or an explanation is provided on why such property holds; due to the widely different features and execution models in these language, it is not......Common folklore in the model transformation community dictates that most transformation languages are Turing-complete. It is however seldom that a proof or an explanation is provided on why such property holds; due to the widely different features and execution models in these language......, it is not immediately obvious what their computational expressiveness is. In this paper we present an analysis that clarifies the computational expressiveness of a large number of model transformation languages. The analysis confirms the folklore for all model transformation languages, except the bidirectional ones...
A Distributed Model of Four-Port Monolithic Transformer
Lee, Dong Ho; Ko, Sangsoo; Jeon, Sang-Hoon; Park, Jae-Woo; Hong, Songcheol
2004-01-01
This paper deals with modeling of a monolithic spiral transformer. The transformer is designed and fabricated as a symmetrical octagonal spiral structure using two-metal layer process on GaAs substrate for input balun applications of 2 GHz and 5 GHz push-pull power amplifiers. A distributed model of the transformer is developed to fit in wide frequency range with four ports. The model includes the skin effect which describes increase in series resistance with frequency. Six different se...
SARC Model for Three-Dimensional Coordinate Transformation
Institute of Scientific and Technical Information of China (English)
YAO Jili; WANG Shuguang; SUN Yating
2006-01-01
In this paper, a transformation model named SARC(static-filter adjustment with restricted condition) is presented, which is more practical and more rigorous in theory and fitting any angle of rotation parameter. The transformation procedure is divided into 4 steps: ① the original and object coordinates can be regarded as observations with errors; ② rigorous formula is firstly deduced in order to compute the first approximation of the transformation parameters by use of four common points and the transformation equation is linearized; ③ calculate the most probable values and variances of the seven transformation parameters by SARC model; ④ to demonstrate validity of SARC , an example is given.
Development and verification of printed circuit board toroidal transformer model
DEFF Research Database (Denmark)
Pejtersen, Jens; Mønster, Jakob Døllner; Knott, Arnold
2013-01-01
by comparing calculated parameters with 3D finite element simulations and experimental measurement results. The developed transformer model shows good agreement with the simulated and measured results. The model can be used to predict the parameters of printed circuit board toroidal transformer configurations......An analytical model of an air core printed circuit board embedded toroidal transformer configuration is presented. The transformer has been developed for galvanic isolation of very high frequency switch-mode dc-dc power converter applications. The theoretical model is developed and verified...
A transformation approach to modelling multi-modal diffusions
DEFF Research Database (Denmark)
Forman, Julie Lyng; Sørensen, Michael
2014-01-01
This paper demonstrates that flexible and statistically tractable multi-modal diffusion models can be attained by transformation of simple well-known diffusion models such as the Ornstein–Uhlenbeck model, or more generally a Pearson diffusion. The transformed diffusion inherits many properties...
Clone Detection for Graph-Based Model Transformation Languages
DEFF Research Database (Denmark)
Strüber, Daniel; Plöger, Jennifer; Acretoaie, Vlad
2016-01-01
has been proposed for programming and modeling languages; yet no specific ones have emerged for model transformation languages. In this paper, we explore clone detection for graph-based model transformation languages. We introduce potential use cases for such techniques in the context of constructive...
On phase transformation models for thermo-mechanically coupled response of Nitinol
Sengupta, Arkaprabha
2011-03-31
Fully coupled thermomechanical models for Nitinol at the grain level are developed in this work to capture the inter-dependence between deformation and temperature under non-isothermal conditions. The martensite transformation equations are solved using a novel algorithm which imposes all relevant constraints on the volume fractions. The numerical implementation of the resulting models within the finite element method is effected by the monolithic solution of the momentum and energy equations. Validation of the models is achieved by means of thin-tube experiments at different strain rates. © 2011 Springer-Verlag.
An ontological model of the practice transformation process.
Sen, Arun; Sinha, Atish P
2016-06-01
Patient-centered medical home is defined as an approach for providing comprehensive primary care that facilitates partnerships between individual patients and their personal providers. The current state of the practice transformation process is ad hoc and no methodological basis exists for transforming a practice into a patient-centered medical home. Practices and hospitals somehow accomplish the transformation and send the transformation information to a certification agency, such as the National Committee for Quality Assurance, completely ignoring the development and maintenance of the processes that keep the medical home concept alive. Many recent studies point out that such a transformation is hard as it requires an ambitious whole-practice reengineering and redesign. As a result, the practices suffer change fatigue in getting the transformation done. In this paper, we focus on the complexities of the practice transformation process and present a robust ontological model for practice transformation. The objective of the model is to create an understanding of the practice transformation process in terms of key process areas and their activities. We describe how our ontology captures the knowledge of the practice transformation process, elicited from domain experts, and also discuss how, in the future, that knowledge could be diffused across stakeholders in a healthcare organization. Our research is the first effort in practice transformation process modeling. To build an ontological model for practice transformation, we adopt the Methontology approach. Based on the literature, we first identify the key process areas essential for a practice transformation process to achieve certification status. Next, we develop the practice transformation ontology by creating key activities and precedence relationships among the key process areas using process maturity concepts. At each step, we employ a panel of domain experts to verify the intermediate representations of the
Observational constraints on the early dark energy model
Institute of Scientific and Technical Information of China (English)
Lei Feng; Yu-Peng Yang
2011-01-01
Dark energy can be studied by its influence on the expansion of the Universe. We investigate current constraints on early dark energy (EDE) achievable by the combined observational data from type Ia supernovae (557), baryon acoustic oscillations, the current cosmic microwave background and the observed Hubble parameter. We find that combining these data sets provides powerful constraints on early dark energy and the best fit values of the parameters in 68％ and 95％ confidencelevel regions are: Ωm0 = 0.2897+0.0149+0.0207 Ωe =0.0129+0.0272+0.0381 = 0.2897-0.0138-0.0194, = 0.0129-0.0129-0.0129, w0 = -1.04l5+0.0891+0.1182 and h = 0.6988+0.0059+0.0083- 1.04155-0.109-0.1604 , 0.6988-0.0058- 0.0081 .
Departure time choice: Modelling individual preferences, intention and constraints
DEFF Research Database (Denmark)
Thorhauge, Mikkel
working hours) as the penalty of late arrival is very likely to be higher for individuals with constraints on arrival time. However, flexibility is not only a matter of fixed arrival time. Activities can be mandatory or discretionary (Yamamoto and Kitamura, 1999), performed alone or jointly with family......D thesis is as follows. Firstly, it provides evidence of a fully efficient stated choice design for a departure time context. Using a pivot design (Rose et al., 2008) built around a reference trip (usually from the day before), the thesis shows that the efficient design performs well in cases where good...... whether they are constrained. The thesis also provides empirical evidences of the policy implication of not accounting for other activities and their constraints. Thirdly, the thesis shows that the departure time choice can be partly explained by psychological factors, which have previously been neglected...
A Three-Box Model of Thermohaline Circulation under the Energy Constraint
Institute of Scientific and Technical Information of China (English)
SHEN Yang; GUAN Yu-Ping; LIANG Chu-Jin; CHEN Da-Ke
2011-01-01
The driving mechanism of thermohaline circulation is still a controversial topic in physical oceanography. Classic theory is based on Stommel's two-box model under buoyancy constraint. Recently, Guan and Huang proposed a new viewpoint in the framework of energy constraint with a two-box model. We extend it to a three-box model,including the effect of wind-driven circulation. Using this simple model, we further study how ocean mixing impacts on thermohaline circulation under the energy constraint.%@@ The driving mechanism of thermohaline circulation is still a controversial topic in physical oceanography.Classic theory is based on Stommel's two-box model under buoyancy constraint.Recently,Guan and Huang proposed a new viewpoint in the framework of energy constraint with a two-box model.We extend it to a three-box model,including the effect of wind-driven circulation.Using this simple model,we further study how ocean mixing impacts on thermohaline circulation under the energy constraint.
Ip, Kuhn; Donoghue, Neil; Kim, Min Kyung; Lun, Desmond S
2014-10-01
Constraint-based modeling has been shown, in many instances, to be useful for metabolic engineering by allowing the prediction of the metabolic phenotype resulting from genetic manipulations. But the basic premise of constraint-based modeling-that of applying constraints to preclude certain behaviors-only makes sense for certain genetic manipulations (such as knockouts and knockdowns). In particular, when genes (such as those associated with a heterologous pathway) are introduced under artificial control, it is unclear how to predict the correct behavior. In this paper, we introduce a modeling method that we call proportional flux forcing (PFF) to model artificially induced enzymatic genes. The model modifications introduced by PFF can be transformed into a set of simple mass balance constraints, which allows computational methods for strain optimization based on flux balance analysis (FBA) to be utilized. We applied PFF to the metabolic engineering of Escherichia coli (E. coli) for free fatty acid (FFA) production-a metabolic engineering problem that has attracted significant attention because FFAs are a precursor to liquid transportation fuels such as biodiesel and biogasoline. We show that PFF used in conjunction with FBA-based computational strain optimization methods can yield non-obvious genetic manipulation strategies that significantly increase FFA production in E. coli. The two mutant strains constructed and successfully tested in this work had peak fatty acid (FA) yields of 0.050 g FA/g carbon source (17.4% theoretical yield) and 0.035 g FA/g carbon source (12.3% theoretical yield) when they were grown using a mixed carbon source of glucose and casamino acids in a ratio of 2-to-1. These yields represent increases of 5.4- and 3.8-fold, respectively, over the baseline strain.
Transformer Model in Wide Frequency Bandwidth for Power Electronics Systems
Directory of Open Access Journals (Sweden)
Carlos Gonzalez-Garcia
2013-01-01
Full Text Available The development of the smart grids leads to new challenges on the power electronics equipment and power transformers. The use of power electronic transformer presents several advantages, but new problems related with the application of high frequency voltage and current components come across. Thus, an accurate knowledge of the transformer behavior in a wide frequency range is mandatory. A novel modeling procedure to relate the transformer physical behavior and its frequency response by means of electrical parameters is presented. Its usability is demonstrated by an example where a power transformer is used as filter and voltage reducer in an AC-DC-AC converter.
Modelling the constraints on consanguineous marriage when fertility declines
Directory of Open Access Journals (Sweden)
Bilal Barakat
2014-01-01
Full Text Available Background: Consanguinity - or marriage between close blood relatives, in particular first cousins - is widely practised and even socially encouraged in many countries. However, in the face of fertility transition where the number of cousins eligible to marry declines, how might such constraints on consanguinity develop in the future? Objective: Numerous studies have stated that the practice cannot continue at present levels and in ist present form in the face of fertility transition. However, the future impact of fertility transition on availability of cousins to marry has not yet been quantified. Methods: We perform a simulation exercise using past and projected net reproduction rates (NRRs derived from the UN. We calculate the average number of cousins of the opposite sex as a function of the average number of children, the average probability of an individual having at least one eligible paternal cousin of the opposite sex, and conclude with an examination of constraints on consanguineous marriage in selected countries under different fertility assumptions. Results: Current and projected fertility levels in Middle Eastern countries will create challenging constraints on the custom once today's birth cohorts reach marriageable age. Conclusions: Either consanguinity prevalence will diminish significantly, or the institution will be forced to adapt by becoming more coercive in the face of reduced choice or at the expense of other social preferences (such as for an older groom wedding a younger bride. Fertility decline affects prospects for social change not only through its well-known consequences for mothers but also through shaping marriage conditions for the next generation.
Cosmological constraints on generalized Chaplygin gas model: Markov Chain Monte Carlo approach
Xu, Lixin; Lu, Jianbo
2010-01-01
We use the Markov Chain Monte Carlo method to investigate a global constraints on the generalized Chaplygin gas (GCG) model as the unification of dark matter and dark energy from the latest observational data: the Constitution dataset of type supernovae Ia (SNIa), the observational Hubble data (OHD), the cluster X-ray gas mass fraction, the baryon acoustic oscillation (BAO), and the cosmic microwave background (CMB) data. In a non-flat universe, the constraint results for GCG model are, $\\Ome...
Cosmological constraints on some supergravity-induced low-energy electroweak models
Energy Technology Data Exchange (ETDEWEB)
Girardi, G.; Salati, P.
1986-02-24
We present constraints on the parameters for models with gravity-induced supersymmetry breaking, obtained from cosmology. This is done by studying the evolution of the density of the lightest supersymmetric particle appearing in the mass spectrum. Our analysis, specifically done for models proposed by Cremmer, Fayet and Girardello, gives severe constraints on the mass of the neutral higgsinos, whereas those on the zino mass are very sensitive to the assumed value of the critical energy density of the Universe. (orig.).
Block Pickard Models for Two-Dimensional Constraints
DEFF Research Database (Denmark)
Forchhammer, Søren; Justesen, Jørn
2009-01-01
whether a PRF consistent with the distribution on the boundary and a 2-D constraint exists. Iterative scaling is used as part of the algorithm, which also determines the conditional probabilities yielding the maximum entropy for the given boundary description if a solution exists. A PRF is defined......In Pickard random fields (PRF), the probabilities of finite configurations and the entropy of the field can be calculated explicitly, but only very simple structures can be incorporated into such a field. Given two Markov chains describing a boundary, an algorithm is presented which determines...
An improved equivalent circuit model of radial mode piezoelectric transformer.
Huang, Yihua; Huang, Wei
2011-05-01
In this paper, both the equivalent circuit models of the radial mode and the coupled thickness vibration mode of the radial mode piezoelectric transformer are deduced, and then with the Y-parameter matrix method and the dual-port network theory, an improved equivalent circuit model for the multilayer radial mode piezoelectric transformer is established. A radial mode transformer sample is tested to verify the equivalent circuit model. The experimental results show that the model proposed in this paper is more precise than the typical model.
Active Versus Passive: Receiver Model Transforms for Diffusive Molecular Communication
Noel, Adam; Makrakis, Dimitrios; Hafid, Abdelhakim
2016-01-01
This paper presents an analytical comparison of the active and passive receiver models in diffusive molecular communication. In the active model, molecules are absorbed when they collide with the receiver surface. In the passive model, the receiver is a virtual boundary that does not affect molecule behavior. Two approaches are presented to derive transforms between the active and passive receiver signals. As an example, we unify the two models for an unbounded diffusion-only molecular communication system with a spherical receiver. As time increases in the three-dimensional system, the transform functions have constant scaling factors, such that the receiver models are effectively equivalent. Methods are presented to enable the transformation of stochastic simulations, which are used to verify the transforms and demonstrate that transforming the simulation of a passive receiver can be more efficient and more accurate than the direct simulation of an absorbing receiver.
Multiphase model for transformation induced plasticity. Extended Leblond's model
Weisz-Patrault, Daniel
2017-09-01
Transformation induced plasticity (TRIP) classically refers to plastic strains observed during phase transitions that occur under mechanical loads (that can be lower than the yield stress). A theoretical approach based on homogenization is proposed to deal with multiphase changes and to extend the validity of the well known and widely used model proposed by Leblond (1989). The approach is similar, but several product phases are considered instead of one and several assumptions have been released. Thus, besides the generalization for several phases, one can mention three main improvements in the calculation of the local equivalent plastic strain: the deviatoric part of the phase transformation is taken into account, both parent and product phases are elastic-plastic with linear isotropic hardening and the applied stress is considered. Results show that classical issues of singularities arising in the Leblond's model (corrected by ad hoc numerical functions or thresholding) are solved in this contribution excepted when the applied equivalent stress reaches the yield stress. Indeed, in this situation the parent phase is entirely plastic as soon as the phase transformation begins and the same singularity as in the Leblond's model arises. A physical explanation of the cutoff function is introduced in order to regularize the singularity. Furthermore, experiments extracted from the literature dealing with multiphase transitions and multiaxial loads are compared with the original Leblond's model and the proposed extended version. For the extended version, very good agreement is observed without any fitting procedures (i.e., material parameters are extracted from other dedicated experiments) and for the original version results are more qualitative.
VMTL: a language for end-user model transformation
DEFF Research Database (Denmark)
Acretoaie, Vlad; Störrle, Harald; Strüber, Daniel
2016-01-01
these guidelines. VMTL draws on our previous work on the usability-oriented Visual Model Query Language. We implement VMTL using the Henshin model transformation engine, and empirically investigate its learnability via two user experiments and a think-aloud protocol analysis. Our experiments, although conducted...... on computer science students exhibiting only some of the characteristics of end-user modelers, show that VMTL compares favorably in terms of learnability with two state-of the-art model transformation languages: Epsilon and Henshin. Our think-aloud protocol analysis confirms many of the design decisions......Model transformation is a key enabling technology of Model-Driven Engineering (MDE). Existing model transformation languages are shaped by and for MDE practitioners—a user group with needs and capabilities which are not necessarily characteristic of modelers in general. Consequently...
The Schwinger Dyson equations and the algebra of constraints of random tensor models at all orders
Energy Technology Data Exchange (ETDEWEB)
Gurau, Razvan, E-mail: rgurau@perimeterinstitute.ca [Perimeter Institute for Theoretical Physics, 31 Caroline St. N, ON N2L 2Y5, Waterloo (Canada)
2012-12-01
Random tensor models for a generic complex tensor generalize matrix models in arbitrary dimensions and yield a theory of random geometries. They support a 1/N expansion dominated by graphs of spherical topology. Their Schwinger Dyson equations, generalizing the loop equations of matrix models, translate into constraints satisfied by the partition function. The constraints have been shown, in the large N limit, to close a Lie algebra indexed by colored rooted D-ary trees yielding a first generalization of the Virasoro algebra in arbitrary dimensions. In this paper we complete the Schwinger Dyson equations and the associated algebra at all orders in 1/N. The full algebra of constraints is indexed by D-colored graphs, and the leading order D-ary tree algebra is a Lie subalgebra of the full constraints algebra.
Directory of Open Access Journals (Sweden)
Salvador Lucas
2015-12-01
Full Text Available Recent developments in termination analysis for declarative programs emphasize the use of appropriate models for the logical theory representing the program at stake as a generic approach to prove termination of declarative programs. In this setting, Order-Sorted First-Order Logic provides a powerful framework to represent declarative programs. It also provides a target logic to obtain models for other logics via transformations. We investigate the automatic generation of numerical models for order-sorted first-order logics and its use in program analysis, in particular in termination analysis of declarative programs. We use convex domains to give domains to the different sorts of an order-sorted signature; we interpret the ranked symbols of sorted signatures by means of appropriately adapted convex matrix interpretations. Such numerical interpretations permit the use of existing algorithms and tools from linear algebra and arithmetic constraint solving to synthesize the models.
An achievement-weighted constraint satisfaction approach to modeling user preferences
Kokawa, Takashi; Ogawa, Hitoshi
The presented study deals with the so-called soft constraint satisfaction problem (SCSP) and proposes an extension to the standard SCSP formulation to accommodate a wider class of over-constrained situations and allow for a generally higher level of flexibility in the constraint-driven problem-solving. The extended modeling approach called Achievement-Weighted Constraint Satisfaction (AWCS) assumes the definition of constraint parameters ``traditional'' for SCSPs, as well as additional parameters specified to dynamically manipulate constraint weights in the course of solution search. These latter parameters make it possible to ``relax'' over-constrained models and obtain a solution even when there are mutually contradicting rules utilized by an AWCS problem-solver. To explore the proposed modeling framework, a task of finding an optimal route in car navigation, based on user preferences - a popular are of research in SCSP studies - is considered. A case study is presented, in which an optimal route is first modeled with constraints reflecting user preferences. Problem solutions having different optimality levels are then obtained. A software system is developed to automate both the optimal route modeling (via interaction with the user) and the solution search processes. The system is applied in an experiment conducted to validate the theoretical ideas. Experimental results are discussed, and conclusions are drawn.
Constraint-Based Fuzzy Models for an Environment with Heterogeneous Information-Granules
Institute of Scientific and Technical Information of China (English)
K. Robert Lai; Yi-Yuan Chiang
2006-01-01
A novel framework for fuzzy modeling and model-based control design is described. Based on the theory of fuzzy constraint processing, the fuzzy model can be viewed as a generalized Takagi-Sugeno (TS) fuzzy model with fuzzy functional consequences. It uses multivariate antecedent membership functions obtained by granular-prototype fuzzy clustering methods and consequent fuzzy equations obtained by fuzzy regression techniques. Constrained optimization is used to estimate the consequent parameters, where the constraints are based on control-relevant a priori knowledge about the modeled process. The fuzzy-constraint-based approach provides the following features. 1) The knowledge base of a constraint-based fuzzy model can incorporate information with various types of fuzzy predicates. Consequently, it is easy to provide a fusion of different types of knowledge. The knowledge can be from data-driven approaches and/or from controlrelevant physical models. 2) A corresponding inference mechanism for the proposed model can deal with heterogeneous information granules. 3) Both numerical and linguistic inputs can be accepted for predicting new outputs.The proposed techniques are demonstrated by means of two examples: a nonlinear function-fitting problem and the well-known Box-Jenkins gas furnace process. The first example shows that the proposed model uses fewer fuzzy predicates achieving similar results with the traditional rule-based approach, while the second shows the performance can be significantly improved when the control-relevant constraints are considered.
Modeling of Incubation Time for Austenite to Ferrite Phase Transformation
Institute of Scientific and Technical Information of China (English)
ZHOU Xiao-guang; LIU Zhen-yu; WU Di; WANG Wei; JIAO Si-hai
2006-01-01
On the basis of the classical nucleation theory, a new model of incubation time for austenite to ferrite transformation has been developed, in which the effect of deformation on austenite has been taken into consideration. To prove the precision of modeling, ferrite transformation starting temperature (Ar3) has been calculated using the Scheil′s additivity rule, and the Ar3 values were measured using a Gleeble 1500 thermomechanical simulator. The Ar3 values provided by the modeling method coincide with the measured ones, indicating that the model is precise in predicting the incubation time for austenite to ferrite transformation in hot deformed steels.
Modelling and Analysis of Real Time Systems with Logic Programming and Constraints
DEFF Research Database (Denmark)
Banda, Gourinath
minimal model forms the basis for verifying the LHA model. We consider two techniques to verify the reactive properties specified as CTL formulas: (i) reachability analysis and (ii) model checking. A systematic translation of LHA models into constraint logic programs is de- fined. This is mechanised...... by a compiler. To facilitate forward and backward reasoning, two different ways to model an LHA are defined. A framework consist- ing of general purpose constraint logic program tools is presented to accomplish the reachability analysis to verify a class of safety and liveness properties. A tool to compute...
LMI-Based Fuzzy Optimal Variance Control of Airfoil Model Subject to Input Constraints
Swei, Sean S.M.; Ayoubi, Mohammad A.
2017-01-01
This paper presents a study of fuzzy optimal variance control problem for dynamical systems subject to actuator amplitude and rate constraints. Using Takagi-Sugeno fuzzy modeling and dynamic Parallel Distributed Compensation technique, the stability and the constraints can be cast as a multi-objective optimization problem in the form of Linear Matrix Inequalities. By utilizing the formulations and solutions for the input and output variance constraint problems, we develop a fuzzy full-state feedback controller. The stability and performance of the proposed controller is demonstrated through its application to the airfoil flutter suppression.
Dilepton constraints in the Inert Doublet Model from Run 1 of the LHC
Belanger, G; Goudelis, A; Herrmann, B; Kraml, S; Sengupta, D
2015-01-01
Searches in final states with two leptons plus missing transverse energy, targeting supersymmetric particles or invisible decays of the Higgs boson, were performed during Run 1 of the LHC. Recasting the results of these analyses in the context of the Inert Doublet Model (IDM) using MadAnalysis 5, we show that they provide constraints on inert scalars that significantly extend previous limits from LEP. Moreover, these LHC constraints allow to test the IDM in the limit of very small Higgs-inert scalar coupling, where the constraints from direct detection of dark matter and the invisible Higgs width vanish.
Observational constraints and differential diagnosis for cosmic evolutionary models
Wang, Deng
2016-01-01
In this paper, we have proposed a plotting method based on the " natural plotting rule " (NPR) which can be used to distinguish different cosmological scenarios more efficiently and obtain more useful information. By using the NPR, we have avoided the blindness to use different diagnostics when discovering that some scenarios can be hardly differentiated from each other, and develop a logical line to adopt different diagnostics. As a concrete instance, we take this method based on the NPR to distinguish several Cardassian scenarios from the base cosmology scenario, and one from the other. We place constraints on three Cardassian cosmological scenarios and their flat versions by utilizing the Type Ia supernovae (SNe Ia), baryonic acoustic oscillations (BAO), cosmic microwave background (CMB) radiation, observational Hubble parameter (OHD) data-sets as well as the single data point from the newest event GW150914, and discover that our results are more stringent than previous results for constraining the cosmolo...
An analysis dictionary learning algorithm under a noisy data model with orthogonality constraint.
Zhang, Ye; Yu, Tenglong; Wang, Wenwu
2014-01-01
Two common problems are often encountered in analysis dictionary learning (ADL) algorithms. The first one is that the original clean signals for learning the dictionary are assumed to be known, which otherwise need to be estimated from noisy measurements. This, however, renders a computationally slow optimization process and potentially unreliable estimation (if the noise level is high), as represented by the Analysis K-SVD (AK-SVD) algorithm. The other problem is the trivial solution to the dictionary, for example, the null dictionary matrix that may be given by a dictionary learning algorithm, as discussed in the learning overcomplete sparsifying transform (LOST) algorithm. Here we propose a novel optimization model and an iterative algorithm to learn the analysis dictionary, where we directly employ the observed data to compute the approximate analysis sparse representation of the original signals (leading to a fast optimization procedure) and enforce an orthogonality constraint on the optimization criterion to avoid the trivial solutions. Experiments demonstrate the competitive performance of the proposed algorithm as compared with three baselines, namely, the AK-SVD, LOST, and NAAOLA algorithms.
An Analysis Dictionary Learning Algorithm under a Noisy Data Model with Orthogonality Constraint
Directory of Open Access Journals (Sweden)
Ye Zhang
2014-01-01
Full Text Available Two common problems are often encountered in analysis dictionary learning (ADL algorithms. The first one is that the original clean signals for learning the dictionary are assumed to be known, which otherwise need to be estimated from noisy measurements. This, however, renders a computationally slow optimization process and potentially unreliable estimation (if the noise level is high, as represented by the Analysis K-SVD (AK-SVD algorithm. The other problem is the trivial solution to the dictionary, for example, the null dictionary matrix that may be given by a dictionary learning algorithm, as discussed in the learning overcomplete sparsifying transform (LOST algorithm. Here we propose a novel optimization model and an iterative algorithm to learn the analysis dictionary, where we directly employ the observed data to compute the approximate analysis sparse representation of the original signals (leading to a fast optimization procedure and enforce an orthogonality constraint on the optimization criterion to avoid the trivial solutions. Experiments demonstrate the competitive performance of the proposed algorithm as compared with three baselines, namely, the AK-SVD, LOST, and NAAOLA algorithms.
Verifying Embedded C Software with Timing Constraints using an Untimed Model Checker
Barreto, Raimundo; Fischer, Bernd
2011-01-01
Embedded systems are everywhere, from home appliances to critical systems such as medical devices. They usually have associated timing constraints that need to be verified for the implementation. Here, we use an untimed bounded model checker to verify timing properties of embedded C programs. We propose an approach to specify discrete time timing constraints using code annotations. The annotated code is then automatically translated to code that manipulates auxiliary timer variables and is thus suitable as input to conventional, untimed software model checker such as ESBMC. Thus, we can check timing constraints in the same way and at the same time as untimed system requirements, and even allow for interaction between them. We applied the proposed method in a case study, and verified timing constraints of a pulse oximeter, a noninvasive medical device that measures the oxygen saturation of arterial blood.
Constraint algebra of general relativity from a formal continuum limit of canonical tensor model
Energy Technology Data Exchange (ETDEWEB)
Sasakura, Naoki [Yukawa Institute for Theoretical Physics, Kyoto University,Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 (Japan); Sato, Yuki [National Institute for Theoretical Physics, School of Physics andMandelstam Institute for Theoretical Physics, University of the Witwatersrand,Wits 2050 (South Africa)
2015-10-16
Canonical tensor model (CTM for short below) is a rank-three tensor model formulated as a totally constrained system in the canonical formalism. In the classical case, the constraints form a first-class constraint Poisson algebra with structures similar to that of the ADM formalism of general relativity, qualifying CTM as a possible discrete formalism for quantum gravity. In this paper, we show that, in a formal continuum limit, the constraint Poisson algebra of CTM with no cosmological constant exactly reproduces that of the ADM formalism. To this end, we obtain the expression of the metric tensor field in general relativity in terms of one of the dynamical rank-three tensors in CTM, and determine the correspondence between the constraints of CTM and those of the ADM formalism. On the other hand, the cosmological constant term of CTM seems to induce non-local dynamics, and is inconsistent with an assumption about locality of the continuum limit.
Institute of Scientific and Technical Information of China (English)
ZHU Limin; HE Gaiyun; SONG Zhanjie
2016-01-01
Product variation reduction is critical to improve process efficiency and product quality, especially for multistage machining process (MMP). However, due to the variation accumulation and propagation, it becomes quite difficult to predict and reduce product variation for MMP. While the method of statistical process control can be used to control product quality, it is used mainly to monitor the process change rather than to analyze the cause of product variation. In this paper, based on a differential description of the contact kinematics of locators and part surfaces, and the geometric constraints equation defined by the locating scheme, an improved analytical variation propagation model for MMP is presented. In which the influence of both locator position and machining error on part quality is considered while, in traditional model, it usually focuses on datum error and fixture error. Coordinate transformation theory is used to reflect the generation and transmission laws of error in the establishment of the model. The concept of deviation matrix is heavily applied to establish an explicit mapping between the geometric deviation of part and the process error sources. In each machining stage, the part deviation is formulized as three separated components corresponding to three different kinds of error sources, which can be further applied to fault identification and design optimization for complicated machining process. An example part for MMP is given out to validate the effectiveness of the methodology. The experiment results show that the model prediction and the actual measurement match well. This paper provides a method to predict part deviation under the influence of fixture error, datum error and machining error, and it enriches the way of quality prediction for MMP.
Directory of Open Access Journals (Sweden)
Mihaela Poienar
2014-09-01
Full Text Available The clock hour figure mathematical model of a threephase transformer can be expressed, in the most plain form, through a 3X3 square matrix, called code matrix. The lines position reflect the modification in the high voltage windings terminal and the columns position reflect the modification in the low voltage winding terminal. The main changes on the transformer winding terminal are: the circular permutation of connection between windings; terminal supply reversal; reverse direction for the phase winding wrapping; reversal the beginning with the end for a phase winding; the connection conversion from N in Z between phase winding or inverse. The analytical form of these changes actually affect the configuration of the mathematical model expressed through a transformations diagram proposed and analyzed in two ways: bipolar version and unipolar version (fanwise. In the end of the paper are presented about the practical exploitation of the transformations diagram.
Modeling and Control of the Saturation’s Transformer
Directory of Open Access Journals (Sweden)
Arif J. Abbas
2013-05-01
Full Text Available This paper investigates the saturable transformer from modeling and control point of view. After implementing the Simulink model of the three phase transformer simulation of a three phase, two-winding transformer is used to examine the transformer under two operating conditions.The first is the secondary terminal short circuited and the second is the secondary terminals connected to a non-unity power factor load to verify the results obtained with those predicted from any analysis using the equivalent circuit. The graphical user interface is used for modeling transformer parameters, obtaining the results, check the stability of the control system, the settling time, the Bode plot, Nyquist and Nicols chart finally recording all currents, voltages and phase shift between them in the steady state condition, initial values of states variables for the nonlinear circuit parameters.
The Drivers of Success in Business Model Transformation
Directory of Open Access Journals (Sweden)
Nenad Savič
2016-01-01
Full Text Available Existing empirical literature on business models is still inconclusive about the key drivers of successful business model transformation. The paper explores this issue by using a single longitudinal case study design in combination with grounded theory approach on a medium-sized, high-tech and globally oriented company. Based on on-site visits, interviews and secondary documentation data analysis, the study identifies six generic drivers of successful business model transformation: transformational leadership, discovery driven decision-making, industry improvement – customer specific orientation, content-oriented communication, self-initiative collaborators, and phased separation strategy. The new drivers supplement our existing knowledge on how successful transformation takes place and add to existing drivers, while extensive discussion of their implications may help the managers to execute business transformations more effectively.
Typical Phases of Transformative Learning: A Practice-Based Model
Nohl, Arnd-Michael
2015-01-01
Empirical models of transformative learning offer important insights into the core characteristics of this concept. Whereas previous analyses were limited to specific social groups or topical terrains, this article empirically typifies the phases of transformative learning on the basis of a comparative analysis of various social groups and topical…
DEPICT: A High-level Formal Language for Modeling Constraint Satisfaction Problems
Institute of Scientific and Technical Information of China (English)
Abdulwahed M. Abbas; Edward P. K. Tsang; Ahmad H. Nasri
2008-01-01
The past decade witnessed rapid development of constraint satisfaction technologies, where algorithms are now able to cope with larger and harder problems. However, owing to the fact that constraints are inherently declarative, attention is quickly turning toward developing high-level programming languages within which such problems can be modeled and also solved. Along these lines, this paper presents DEPICT, the language. Its use is illustrated through modeling a number of benchmark examples. The paper continues with a description of a prototype system within which such models may be interpreted. The paper concludes with a description of a sample run of this interpreter showing how a problem modeled as such is typically solved.
Statistical analysis of probabilistic models of software product lines with quantitative constraints
DEFF Research Database (Denmark)
Beek, M.H. ter; Legay, A.; Lluch Lafuente, Alberto
2015-01-01
We investigate the suitability of statistical model checking for the analysis of probabilistic models of software product lines with complex quantitative constraints and advanced feature installation options. Such models are specified in the feature-oriented language QFLan, a rich process algebra...
MISTRAL: A language for model transformations in the MOF meta-modeling architecture
Kurtev, I.; Berg, van den K.G.
2005-01-01
In the Meta Object Facility (MOF) meta-modeling architecture a number of model transformation scenarios can be identified. It could be expected that a meta-modeling architecture will be accompanied by a transformation technology supporting the model transformation scenarios in a uniform way. Despite
Yu. Moshin, Pavel; Reshetnyak, Alexander A.
2016-07-01
We continue our research1-4 and extend the class of finite BRST-anti-BRST transformations with odd-valued parameters λa, a = 1, 2, introduced in these works. In doing so, we evaluate the Jacobians induced by finite BRST-anti-BRST transformations linear in functionally-dependent parameters, as well as those induced by finite BRST-anti-BRST transformations with arbitrary functional parameters. The calculations cover the cases of gauge theories with a closed algebra, dynamical systems with first-class constraints, and general gauge theories. The resulting Jacobians in the case of linearized transformations are different from those in the case of polynomial dependence on the parameters. Finite BRST-anti-BRST transformations with arbitrary parameters induce an extra contribution to the quantum action, which cannot be absorbed into a change of the gauge. These transformations include an extended case of functionally-dependent parameters that implies a modified compensation equation, which admits nontrivial solutions leading to a Jacobian equal to unity. Finite BRST-anti-BRST transformations with functionally-dependent parameters are applied to the Standard Model, and an explicit form of functionally-dependent parameters λa is obtained, providing the equivalence of path integrals in any 3-parameter Rξ-like gauges. The Gribov-Zwanziger theory is extended to the case of the Standard Model, and a form of the Gribov horizon functional is suggested in the Landau gauge, as well as in Rξ-like gauges, in a gauge-independent way using field-dependent BRST-anti-BRST transformations, and in Rξ-like gauges using transverse-like non-Abelian gauge fields.
Modeling of amorphous carbon structures with arbitrary structural constraints.
Jornada, F H; Gava, V; Martinotto, A L; Cassol, L A; Perottoni, C A
2010-10-06
In this paper we describe a method to generate amorphous structures with arbitrary structural constraints. This method employs the simulated annealing algorithm to minimize a simple yet carefully tailored cost function (CF). The cost function is composed of two parts: a simple harmonic approximation for the energy-related terms and a cost that penalizes configurations that do not have atoms in the desired coordinations. Using this approach, we generated a set of amorphous carbon structures spawning nearly all the possible combinations of sp, sp(2) and sp(3) hybridizations. The bulk moduli of this set of amorphous carbons structures was calculated using Brenner's potential. The bulk modulus strongly depends on the mean coordination, following a power-law behavior with an exponent ν = 1.51 ± 0.17. A modified cost function that segregates carbon with different hybridizations is also presented, and another set of structures was generated. With this new set of amorphous materials, the correlation between the bulk modulus and the mean coordination weakens. The method proposed can be easily modified to explore the effects on the physical properties of the presence of hydrogen, dangling bonds, and structural features such as carbon rings.
Models and constraints for new physics at the energy, intensity, and cosmic frontiers
Barello, Gregory
The modern era of particle physics is driven by experimental anomalies. Experimental efforts have become increasingly diverse and are producing enormous volumes of data. In such a highly data-driven scientific environment theoretical models are necessary to understand this data and to help inform the development of new experimental approaches. In this dissertation I present two significant contributions to this effort relevant to the energy, intensity, and cosmic frontiers of modern particle physics research. Part 1 of this dissertation discusses methods to understand modern dark matter direct detection results. In particular I present an analysis under the hypothesis of inelastic dark matter, which supposes that dark matter must scatter inelastically, i.e. that it must gain or loose mass during a collision with atomic nuclei. This hypothesis is attractive because it can alleviate otherwise contradictory results from a number of dark matter detection facilities. The main conclusion of this work is a presentation of the analytical tools, along with a mathematica package that can be used to run the analysis, and the discovery that there are regions of inelastic dark matter parameter space which are consistent with all current experimental results, and constraints. Part 2 of this dissertation discusses a phenomenon of modern interest called kinetic mixing which allows particles from the standard model to spontaneously transform into particles which experience a new, as of yet undiscovered, force. This phenomenon is relatively common and well motivated theoretically and has motivated significant experimental effort. In this work, I present an analysis of a general case of kinetic mixing, called nonabelian kinetic mixing. This work shows that, In general, kinetic mixing predicts the existence of a new particle and that, under certain conditions, this particle could be detected at modern particle colliders. Furthermore, the mass of this particle is related to the
CELL SCALE HOST-PATHOGEN MODELING: ANOTHER BRANCH IN THE EVOLUTION OF CONSTRAINT-BASED METHODS
Directory of Open Access Journals (Sweden)
Neema eJamshidi
2015-10-01
Full Text Available Constraint-based models have become popular methods for systems biology as they enable the integration of complex, disparate datasets in a biologically cohesive framework that also supports the description of biological processes in terms of basic physicochemical constraints and relationships. The scope, scale, and application of genome scale models have grown from single cell bacteria to multi-cellular interaction modeling; host-pathogen modeling represents one of these examples at the current horizon of constraint-based methods. There are now a small number of examples of host-pathogen constraint-based models in the literature, however there has not yet been a definitive description of the methodology required for the functional integration of genome scale models in order to generate simulation capable host-pathogen models. Herein we outline a systematic procedure to produce functional host-pathogen models, highlighting steps which require debugging and iterative revisions in order to successfully build a functional model. The construction of such models will enable the exploration of host-pathogen interactions by leveraging the growing wealth of omic data in order to better understand mechanism of infection and identify novel therapeutic strategies.
An Extended Model Driven Framework for End-to-End Consistent Model Transformation
Directory of Open Access Journals (Sweden)
Mr. G. Ramesh
2016-08-01
Full Text Available Model Driven Development (MDD results in quick transformation from models to corresponding systems. Forward engineering features of modelling tools can help in generating source code from models. To build a robust system it is important to have consistency checking in the design models and the same between design model and the transformed implementation. Our framework named as Extensible Real Time Software Design Inconsistency Checker (XRTSDIC proposed in our previous papers supports consistency checking in design models. This paper focuses on automatic model transformation. An algorithm and defined transformation rules for model transformation from UML class diagram to ERD and SQL are being proposed. The model transformation bestows many advantages such as reducing cost of development, improving quality, enhancing productivity and leveraging customer satisfaction. Proposed framework has been enhanced to ensure that the transformed implementations conform to their model counterparts besides checking end-to-end consistency.
A Visual Entity-Relationship Model for Constraint-Based University Timetabling
Abdelraouf, Islam; Gervet, Carmen
2011-01-01
University timetabling (UTT) is a complex problem due to its combinatorial nature but also the type of constraints involved. The holy grail of (constraint) programming: "the user states the problem the program solves it" remains a challenge since solution quality is tightly coupled with deriving "effective models", best handled by technology experts. In this paper, focusing on the field of university timetabling, we introduce a visual graphic communication tool that lets the user specify her problem in an abstract manner, using a visual entity-relationship model. The entities are nodes of mainly two types: resource nodes (lecturers, assistants, student groups) and events nodes (lectures, lab sessions, tutorials). The links between the nodes signify a desired relationship between them. The visual modeling abstraction focuses on the nature of the entities and their relationships and abstracts from an actual constraint model.
Modelling Parsing Constraints with High-Dimensional Context Space.
Burgess, Curt; Lund, Kevin
1997-01-01
Presents a model of high-dimensional context space, the Hyperspace Analogue to Language (HAL), with a series of simulations modelling human empirical results. Proposes that HAL's context space can be used to provide a basic categorization of semantic and grammatical concepts; model certain aspects of morphological ambiguity in verbs; and provide…
Design Transformations for Rule-based Procedural Modeling
Lienhard, Stefan
2017-05-24
We introduce design transformations for rule-based procedural models, e.g., for buildings and plants. Given two or more procedural designs, each specified by a grammar, a design transformation combines elements of the existing designs to generate new designs. We introduce two technical components to enable design transformations. First, we extend the concept of discrete rule switching to rule merging, leading to a very large shape space for combining procedural models. Second, we propose an algorithm to jointly derive two or more grammars, called grammar co-derivation. We demonstrate two applications of our work: we show that our framework leads to a larger variety of models than previous work, and we show fine-grained transformation sequences between two procedural models.
A Two-Layered Model for Dynamic Supply Chain Management Considering Transportation Constraint
Tanimizu, Yoshitaka; Harada, Kana; Ozawa, Chisato; Iwamura, Koji; Sugimura, Nobuhiro
This research proposes a two-layered model for dynamic supply chain management considering transportation constraint. The model provides a method for suppliers to estimate suitable prices and delivery times of products based on not only production schedules but also transportation plans in consideration of constraints about shipping times and loading capacities for transportation. A prototype of dynamic supply chain simulation system was developed and some computational experiments were carried out in order to verify the effectiveness of the model. The prototype system is available to determine suitable shipping times and loading capacities of transportation vehicles.
Constraint-based modeling and kinetic analysis of the Smad dependent TGF-beta signaling pathway.
Directory of Open Access Journals (Sweden)
Zhike Zi
Full Text Available BACKGROUND: Investigation of dynamics and regulation of the TGF-beta signaling pathway is central to the understanding of complex cellular processes such as growth, apoptosis, and differentiation. In this study, we aim at using systems biology approach to provide dynamic analysis on this pathway. METHODOLOGY/PRINCIPAL FINDINGS: We proposed a constraint-based modeling method to build a comprehensive mathematical model for the Smad dependent TGF-beta signaling pathway by fitting the experimental data and incorporating the qualitative constraints from the experimental analysis. The performance of the model generated by constraint-based modeling method is significantly improved compared to the model obtained by only fitting the quantitative data. The model agrees well with the experimental analysis of TGF-beta pathway, such as the time course of nuclear phosphorylated Smad, the subcellular location of Smad and signal response of Smad phosphorylation to different doses of TGF-beta. CONCLUSIONS/SIGNIFICANCE: The simulation results indicate that the signal response to TGF-beta is regulated by the balance between clathrin dependent endocytosis and non-clathrin mediated endocytosis. This model is useful to be built upon as new precise experimental data are emerging. The constraint-based modeling method can also be applied to quantitative modeling of other signaling pathways.
Cosmological Constraints on the Modified Entropic Force Model
Wei, Hao
2010-01-01
Very recently, Verlinde considered a theory in which space is emergent through a holographic scenario, and proposed that gravity can be explained as an entropic force caused by changes in the information associated with the positions of material bodies. Then, motivated by the Debye model in thermodynamics which is very successful in very low temperatures, Gao modified the entropic force scenario. The modified entropic force (MEF) model is in fact a modified gravity model, and the universe can...
Crawford, William J.; Smith, Polly J.; Milliff, Ralph F.; Fiechter, Jerome; Wikle, Christopher K.; Edwards, Christopher A.; Moore, Andrew M.
2016-12-01
A new approach is explored for computing estimates of the error covariance associated with the intrinsic errors of a numerical forecast model in regions characterized by upwelling and downwelling. The approach used is based on a combination of strong constraint data assimilation, twin model experiments, linear inverse modeling, and Bayesian hierarchical modeling. The resulting model error covariance estimates Q are applied to a model of the California Current System using weak constraint four-dimensional variational (4D-Var) data assimilation to compute estimates of the ocean circulation. The results of this study show that the estimates of Q derived following our approach lead to demonstrable improvements in the model circulation estimates and isolate regions where model errors are likely to be important and that have been independently identified in the same model in previously published work.
Interplay between Constraints, Objectives, and Optimality for Genome-Scale Stoichiometric Models
Maarleveld, T.R.; Wortel, M.; Olivier, B.G.; Teusink, B.; Bruggeman, F.J.
2015-01-01
High-throughput data generation and genome-scale stoichiometric models have greatly facilitated the comprehensive study of metabolic networks. The computation of all feasible metabolic routes with these models, given stoichiometric, thermodynamic, and steady-state constraints, provides important ins
Experience Report: Constraint-Based Modelling and Simulation of Railway Emergency Response Plans
DEFF Research Database (Denmark)
Debois, Søren; Hildebrandt, Thomas; Sandberg, Lene
2016-01-01
We report on experiences from a case study applying a constraint-based process-modelling and -simulation tool, dcrgraphs.net, to the modelling and rehearsal of railway emergency response plans with domain experts. The case study confirmed the approach as a viable means for domain experts to analyse...... and security processes in the danish public transport sector and their dependency on ICT....
Numerical Modeling of Arsenic Mobility during Reductive Iron-Mineral Transformations.
Rawson, Joey; Prommer, Henning; Siade, Adam; Carr, Jackson; Berg, Michael; Davis, James A; Fendorf, Scott
2016-03-01
Millions of individuals worldwide are chronically exposed to hazardous concentrations of arsenic from contaminated drinking water. Despite massive efforts toward understanding the extent and underlying geochemical processes of the problem, numerical modeling and reliable predictions of future arsenic behavior remain a significant challenge. One of the key knowledge gaps concerns a refined understanding of the mechanisms that underlie arsenic mobilization, particularly under the onset of anaerobic conditions, and the quantification of the factors that affect this process. In this study, we focus on the development and testing of appropriate conceptual and numerical model approaches to represent and quantify the reductive dissolution of iron oxides, the concomitant release of sorbed arsenic, and the role of iron-mineral transformations. The initial model development in this study was guided by data and hypothesized processes from a previously reported,1 well-controlled column experiment in which arsenic desorption from ferrihydrite coated sands by variable loads of organic carbon was investigated. Using the measured data as constraints, we provide a quantitative interpretation of the processes controlling arsenic mobility during the microbial reductive transformation of iron oxides. Our analysis suggests that the observed arsenic behavior is primarily controlled by a combination of reductive dissolution of ferrihydrite, arsenic incorporation into or co-precipitation with freshly transformed iron minerals, and partial arsenic redox transformations.
Systematic assignment of thermodynamic constraints in metabolic network models
Kümmel, Anne; Panke, Sven; Heinemann, Matthias
2006-01-01
Background: The availability of genome sequences for many organisms enabled the reconstruction of several genome-scale metabolic network models. Currently, significant efforts are put into the automated reconstruction of such models. For this, several computational tools have been developed that par
Integrating Articulatory Constraints into Models of Second Language Phonological Acquisition
Colantoni, Laura; Steele, Jeffrey
2008-01-01
Models such as Eckman's markedness differential hypothesis, Flege's speech learning model, and Brown's feature-based theory of perception seek to explain and predict the relative difficulty second language (L2) learners face when acquiring new or similar sounds. In this paper, we test their predictive adequacy as concerns native English speakers'…
Rigorous bounds on aerosol optical properties from measurement and/or model constraints
McGraw, Robert; Fierce, Laura
2016-04-01
Sparse-particle aerosol models are an attractive alternative to sectional and modal methods for representation of complex, generally mixed particle populations. In the quadrature method of moments (QMOM) a small set of abscissas and weights, determined from distributional moments, provides the sparse set. Linear programming (LP) yields a generalization of the QMOM that is especially convenient for sparse particle selection. In this paper we use LP to obtain rigorous, nested upper and lower bounds to aerosol optical properties in terms of a prescribed Bayesian-like sequence of model or simulated measurement constraints. Examples of such constraints include remotely-sensed light extinction at different wavelengths, modeled particulate mass, etc. Successive reduction in bound separation with each added constraint provides a quantitative measure of its contextual information content. The present study is focused on univariate populations as a first step towards development of new simulation algorithms for tracking the physical and optical properties of multivariate particle populations.
Institute of Scientific and Technical Information of China (English)
HOU Fu-jun; WU Qi-zong
2007-01-01
A method for modeling the parallel machine scheduling problems with fuzzy parameters and precedence constraints based on credibility measure is provided.For the given n jobs to be processed on m machines, it is assumed that the processing times and the due dates are nonnegative fuzzy numbers and all the weights are positive, crisp numbers.Based on credibility measure, three parallel machine scheduling problems and a goal-programming model are formulated.Feasible schedules are evaluated not only by their objective values but also by the credibility degree of satisfaction with their precedence constraints.The genetic algorithm is utilized to find the best solutions in a short period of time.An illustrative numerical example is also given.Simulation results show that the proposed models are effective, which can deal with the parallel machine scheduling problems with fuzzy parameters and precedence constraints based on credibility measure.
Directory of Open Access Journals (Sweden)
Wei Zhang
2015-11-01
Full Text Available This article investigates the capacity problem of an integrated remote wireless sensor and satellite network (IWSSN in emergency scenarios. We formulate a general model to evaluate the remote sensor and satellite network capacity. Compared to most existing works for ground networks, the proposed model is time varying and space oriented. To capture the characteristics of a practical network, we sift through major capacity-impacting constraints and analyze the influence of these constraints. Specifically, we combine the geometric satellite orbit model and satellite tool kit (STK engineering software to quantify the trends of the capacity constraints. Our objective in analyzing these trends is to provide insights and design guidelines for optimizing the integrated remote wireless sensor and satellite network schedules. Simulation results validate the theoretical analysis of capacity trends and show the optimization opportunities of the IWSSN.
Model-Independent Indirect Detection Constraints on Hidden Sector Dark Matter
Elor, Gilly; Slatyer, Tracy R; Xue, Wei
2015-01-01
If dark matter inhabits an expanded "hidden sector", annihilations may proceed through sequential decays or multi-body final states. We map out the potential signals and current constraints on such a framework in indirect searches, using a model-independent setup based on multi-step hierarchical cascade decays. While remaining agnostic to the details of the hidden sector model, our framework captures the generic broadening of the spectrum of secondary particles (photons, neutrinos, e+e- and antiprotons) relative to the case of direct annihilation to Standard Model particles. We explore how indirect constraints on dark matter annihilation limit the parameter space for such cascade/multi-particle decays. We investigate limits from the cosmic microwave background by Planck, the Fermi measurement of photons from the dwarf galaxies, and positron data from AMS-02. The presence of a hidden sector can change the constraints on the dark matter annihilation cross section by up to an order of magnitude in either directi...
Park, G T
1994-01-01
We perform a combined analysis of two stringent constraints on two Higgs doublet model, coming from the recently announced CLEO II bound on $B(b \\rightarrow s \\gamma)$ and $Z \\rightarrow b \\overline b$ and from the recent LEP data on the ratio $\\Gamma(Z\\rightarrow b\\overline b)\\over{\\Gamma(Z\\rightarrow hadrons)}$. We include one-loop vertex corrections to $Z \\rightarrow b \\overline b$ in the model. We find that although the CLEO II bound serves as the strongest constraint present in the charged Higgs sector of the model, the current LEP value for $R_b$ may also provide a further constraint for $\\tan\\beta<1$.
A transformation approach for collaboration based requirement models
Harbouche, Ahmed; Mokhtari, Aicha
2012-01-01
Distributed software engineering is widely recognized as a complex task. Among the inherent complexities is the process of obtaining a system design from its global requirement specification. This paper deals with such transformation process and suggests an approach to derive the behavior of a given system components, in the form of distributed Finite State Machines, from the global system requirements, in the form of an augmented UML Activity Diagrams notation. The process of the suggested approach is summarized in three steps: the definition of the appropriate source Meta-Model (requirements Meta-Model), the definition of the target Design Meta-Model and the definition of the rules to govern the transformation during the derivation process. The derivation process transforms the global system requirements described as UML diagram activities (extended with collaborations) to system roles behaviors represented as UML finite state machines. The approach is implemented using Atlas Transformation Language (ATL).
Model independent constraints on mass-varying neutrino scenarios
Franca, Urbano; Lesgourgues, Julien; Pastor, Sergio
2009-01-01
Models of dark energy in which neutrinos interact with the scalar field supposed to be responsible for the acceleration of the universe usually imply a variation of the neutrino masses on cosmological time scales. In this work we propose a parameterization for the neutrino mass variation that captures the essentials of those scenarios and allows to constrain them in a model independent way, that is, without resorting to any particular scalar field model. Using WMAP 5yr data combined with the matter power spectrum of SDSS and 2dFGRS, the limit on the present value of the neutrino mass is $m_0 \\equiv m_{\
K factor estimation in distribution transformers using linear regression models
Directory of Open Access Journals (Sweden)
Juan Miguel Astorga Gómez
2016-06-01
Full Text Available Background: Due to massive incorporation of electronic equipment to distribution systems, distribution transformers are subject to operation conditions other than the design ones, because of the circulation of harmonic currents. It is necessary to quantify the effect produced by these harmonic currents to determine the capacity of the transformer to withstand these new operating conditions. The K-factor is an indicator that estimates the ability of a transformer to withstand the thermal effects caused by harmonic currents. This article presents a linear regression model to estimate the value of the K-factor, from total current harmonic content obtained with low-cost equipment.Method: Two distribution transformers that feed different loads are studied variables, current total harmonic distortion factor K are recorded, and the regression model that best fits the data field is determined. To select the regression model the coefficient of determination R2 and the Akaike Information Criterion (AIC are used. With the selected model, the K-factor is estimated to actual operating conditions.Results: Once determined the model it was found that for both agricultural cargo and industrial mining, present harmonic content (THDi exceeds the values that these transformers can drive (average of 12.54% and minimum 8,90% in the case of agriculture and average value of 18.53% and a minimum of 6.80%, for industrial mining case.Conclusions: When estimating the K factor using polynomial models it was determined that studied transformers can not withstand the current total harmonic distortion of their current loads. The appropriate K factor for studied transformer should be 4; this allows transformers support the current total harmonic distortion of their respective loads.
Equilibrium Model Constraints on Baryon Cycling Across Cosmic Time
Mitra, Sourav; Finlator, Kristian
2014-01-01
Galaxies strongly self-regulate their growth via energetic feedback from stars, supernovae, and black holes, but these processes are among the least understood aspects of galaxy formation theory. We present an analytic galaxy evolution model that directly constrains such feedback processes from observed galaxy scaling relations. The equilibrium model, which is broadly valid for star-forming central galaxies that dominate cosmic star formation, is based on the ansatz that galaxies live in a slowly-evolving equilibrium between inflows, outflows, and star formation. Using a Bayesian Monte Carlo Markov chain approach, we constrain our model to match observed galaxy scaling relations between stellar mass and halo mass, star formation rate, and metallicity from 0
Model quality assessment using distance constraints from alignments
DEFF Research Database (Denmark)
Paluszewski, Martin; Karplus, Kevin
2008-01-01
Given a set of alternative models for a specific protein sequence, the model quality assessment (MQA) problem asks for an assignment of scores to each model in the set. A good MQA program assigns these scores such that they correlate well with real quality of the models, ideally scoring best...... with the best MQA methods that were assessed at CASP7. We also propose a new evaluation measure, Kendall's tau, that is more interpretable than conventional measures used for evaluating MQA methods (Pearson's r and Spearman's rho). We show clear examples where Kendall's tau agrees much more with our intuition...... of a correct MQA, and we therefore propose that Kendall's tau be used for future CASP MQA assessments. Proteins 2009. (c) 2008 Wiley-Liss, Inc....
Modeling Io's Heat Flow: Constraints from Galileo PPR Data
Rathbun, J. A.; Spencer, J. R.; Tamppari, L. K.
2000-01-01
We attempt to improve on previous Io heat flow estimates by using higher resolution data from Galileo Photopolarimeter Radiometer (PPR) and improved thermophysical models of the surface, including finite thermal inertia, the pedestal effect, and disk-resolved radiance.
Observational Constraints on a Variable Dark Energy Model
Movahed, M S; Movahed, Mohammad Sadegh; Rahvar, Sohrab
2006-01-01
We present cosmological tests for a phenomenological parametrization of quintessence model with time-varying equation of state on low, intermediate and high redshift observations \\cite{w04}. We study the sensitivity of the comoving distance and volume element with the Alcock-Paczynski test to the time varying model of dark energy. At the intermediate redshifts, Gold supernova Type Ia data is used to fit the quintessence model to the observed distance modulus. The value of the observed acoustic angular scale by WMAP experiment also is compared with the model. The combined result of CMB and SNIa data confines $w=p/\\rho$ to be more than -1.3 which can violate the dominant energy condition.
New Experimental Constraints for the Standard Model from Muon Decay
Bayes, R; Hillairet, A; Davydov, Yu I; Depommier, P; Faszer, W; Gagliardi, C A; Gaponenko, A; Gill, D R; Grossheim, A; Gumplinger, P; Hasinoff, M D; Henderson, R S; Hu, J; Koetke, D D; MacDonald, R P; Marshall, G; Mathie, E L; Mischke, R E; Olchanski, K; Olin, A; Openshaw, R; Poutissou, J -M; Poutissou, R; Selivanov, V; Sheffer, G; Shin, B; Stanislaus, T D S; Tacik, R; Tribble, R E
2010-01-01
The TWIST Collaboration has completed a new measurement of the energy-angle spectrum of positrons from the decay of highly polarized muons. A simultaneous measurement of the muon decay parameters {\\rho}, {\\delta}, and (P_{\\mu}){\\xi} tests the Standard Model (SM) in a purely leptonic process and provides improved limits for relevant extensions to the SM. Specifically, these results set significant new limits on the heavy $W$ mass and the mixing angle in a class of left-right symmetric models.
Model independence of constraints on particle dark matter
Energy Technology Data Exchange (ETDEWEB)
Griest, K.; Sadoulet, B.
1989-03-01
The connection between the annihilation, elastic, and production cross sections is reviewed, showing how a general lower limit on the interaction rate in a detector is obtained from the requirement that a particle be the dark matter. High energy production experiments further constrain models, making very light dark matter particles unlikely. Special attention is paid to the uncertainties, loopholes and model dependencies that go into the arguments and several examples are given. 12 refs., 6 figs.
Constraints on gauge-Higgs unification models at the LHC
Kitazawa, Noriaki; Sakai, Yuki
2016-02-01
We examine the possibility of observing the Kaluza-Klein (KK) gluons in gauge-Higgs unification models at the LHC with the energy s=14 TeV. We consider a benchmark model with the gauge symmetry SU(3)C×SU(3)W in five-dimensional spacetime, where SU(3)C is the gauge symmetry of the strong interaction and SU(3)W is that for the electroweak interaction and a Higgs doublet field. It is natural in general to introduce SU(3)C gauge symmetry in five-dimensional spacetime as well as SU(3)W gauge symmetry in gauge-Higgs unification (GHU) models. Since the fifth dimension is compactified to S1/Z 2 orbifold, there are KK modes of gluons in low-energy effective theory in four-dimensional spacetime. We investigate the resonance contribution of the first KK gluon to dijet invariant mass distribution at the LHC, and provide signal-to-noise ratios in various cases of KK gluon masses and kinematical cuts. Although the results are given in a specific benchmark model, we discuss their application to general GHU models with KK gluons. GHU models can be verified or constrained through the physics of the strong interaction, though they are proposed to solve the naturalness problem in electroweak symmetry breaking.
Lu, Jianbo; Xu, Lixin; Wu, Yabo; Liu, Molin
2011-01-01
We use the Markov Chain Monte Carlo method to investigate a global constraints on the modified Chaplygin gas (MCG) model as the unification of dark matter and dark energy from the latest observational data: the Union2 dataset of type supernovae Ia (SNIa), the observational Hubble data (OHD), the cluster X-ray gas mass fraction, the baryon acoustic oscillation (BAO), and the cosmic microwave background (CMB) data. In a flat universe, the constraint results for MCG model are, $\\Omega_{b}h^{2}=0...
Constraints on Hidden Photon Models from Electron g-2 and Hydrogen Spectroscopy
Endo, Motoi; Mishima, Go
2012-01-01
The hidden photon model is one of the simplest models which can explain the anomaly of the muon anomalous magnetic moment (g-2). The experimental constraints are studied in detail, which come from the electron g-2 and the hydrogen transition frequencies. The input parameters are set carefully in order to take dark photon contributions into account and to prevent the analysis from being self-inconsistent. It is shown that the new analysis provides a constraint severer by more than one order of magnitude than the previous result.
A note on a model for quay crane scheduling with non-crossing constraints
DEFF Research Database (Denmark)
Santini, Alberto; Friberg, Henrik Alsing; Røpke, Stefan
2015-01-01
This article studies the quay crane scheduling problem with non-crossing constraints, which is an operational problem that arises in container terminals. An enhancement to a mixed integer programming model for the problem is proposed and a new class of valid inequalities is introduced. Computatio......This article studies the quay crane scheduling problem with non-crossing constraints, which is an operational problem that arises in container terminals. An enhancement to a mixed integer programming model for the problem is proposed and a new class of valid inequalities is introduced....... Computational results show the effectiveness of these enhancements in solving the problem to optimality....
Directory of Open Access Journals (Sweden)
Sanzo Miyazawa
Full Text Available BACKGROUND: Empirical substitution matrices represent the average tendencies of substitutions over various protein families by sacrificing gene-level resolution. We develop a codon-based model, in which mutational tendencies of codon, a genetic code, and the strength of selective constraints against amino acid replacements can be tailored to a given gene. First, selective constraints averaged over proteins are estimated by maximizing the likelihood of each 1-PAM matrix of empirical amino acid (JTT, WAG, and LG and codon (KHG substitution matrices. Then, selective constraints specific to given proteins are approximated as a linear function of those estimated from the empirical substitution matrices. RESULTS: Akaike information criterion (AIC values indicate that a model allowing multiple nucleotide changes fits the empirical substitution matrices significantly better. Also, the ML estimates of transition-transversion bias obtained from these empirical matrices are not so large as previously estimated. The selective constraints are characteristic of proteins rather than species. However, their relative strengths among amino acid pairs can be approximated not to depend very much on protein families but amino acid pairs, because the present model, in which selective constraints are approximated to be a linear function of those estimated from the JTT/WAG/LG/KHG matrices, can provide a good fit to other empirical substitution matrices including cpREV for chloroplast proteins and mtREV for vertebrate mitochondrial proteins. CONCLUSIONS/SIGNIFICANCE: The present codon-based model with the ML estimates of selective constraints and with adjustable mutation rates of nucleotide would be useful as a simple substitution model in ML and Bayesian inferences of molecular phylogenetic trees, and enables us to obtain biologically meaningful information at both nucleotide and amino acid levels from codon and protein sequences.
Bernoulli substitution in the Ramsey model: Optimal trajectories under control constraints
Krasovskii, A. A.; Lebedev, P. D.; Tarasyev, A. M.
2017-05-01
We consider a neoclassical (economic) growth model. A nonlinear Ramsey equation, modeling capital dynamics, in the case of Cobb-Douglas production function is reduced to the linear differential equation via a Bernoulli substitution. This considerably facilitates the search for a solution to the optimal growth problem with logarithmic preferences. The study deals with solving the corresponding infinite horizon optimal control problem. We consider a vector field of the Hamiltonian system in the Pontryagin maximum principle, taking into account control constraints. We prove the existence of two alternative steady states, depending on the constraints. A proposed algorithm for constructing growth trajectories combines methods of open-loop control and closed-loop regulatory control. For some levels of constraints and initial conditions, a closed-form solution is obtained. We also demonstrate the impact of technological change on the economic equilibrium dynamics. Results are supported by computer calculations.
New Models of Mechanisms for the Motion Transformation
Petrović, Tomislav; Ivanov, Ivan
In this paper two new mechanisms for the motion transformations are presented: screw mechanism for the transformation of one-way circular into two-way linear motion with impulse control and worm-planetary gear train with extremely height gear ratio. Both mechanisms represent new models of construction solutions for which patent protection has been achieved. These mechanisms are based on the application of the differential gearbox with two degrees of freedom. They are characterized by series of kinematic impacts at motion transformation and the possibility of temporary or permanent changes in the structure by subtracting the redundant degree of freedom. Thus the desired characteristic of the motion transformation is achieved. For each mechanism separately the principles of motion and transformation are described and the basic equations that describe the interdependence of geometric and kinematic and kinetic parameters of the system dynamics are given. The basic principles of controlling new mechanisms for motion transformation have been pointed to and the basic constructional performances which may find practical application have been given. The physical models of new systems of motion transformation have been designed and their operation has been presented. Performed experimental researches confirmed the theoretical results and very favorable kinematic characteristics of the mechanisms.
Constraints on gauge-Higgs unification models at the LHC
Kitazawa, Noriaki
2015-01-01
We examine the possibility of observing the Kaluza-Klein gluons in gauge-Higgs unification models at the LHC with the energy sqrt{s}=14 TeV. We consider a benchmark model with the gauge symmetry SU(3)_C x SU(3)_W in five-dimensional space-time, where SU(3)_C is the gauge symmetry of the strong interaction and SU(3)_W is that for the electroweak interaction and a Higgs doublet field. It is natural in general to introduce SU(3)_C gauge symmetry in five-dimensional space-time as well as SU(3)_W gauge symmetry in gauge-Higgs unification models. Since the fifth dimension is compactified to S1/Z2 orbifold, there are Kaluza-Klein modes of gluons in low-energy effective theory in four-dimensional space-time. We investigate the resonance contribution of the first Kaluza-Klein gluon to dijet invariant mass distribution at the LHC, and provide signal-to-noise ratios in various cases of Kaluza-Klein gluon masses and kinematical cuts. Although the results are given in a specific benchmark model, we discuss their applicati...
Understanding lithospheric stresses in Arctic: constraints and models
Medvedev, Sergei; Minakov, Alexander; Lebedeva-Ivanova, Nina; Gaina, Carmen
2016-04-01
This pilot project aims to model stress patterns and analyze factors controlling lithospheric stresses in Arctic. The project aims to understand the modern stresses in Arctic as well as to define the ways to test recent hypotheses about Cenozoic evolution of the region. The regions around Lomonosov Ridge and Barents Sea are of particular interest driven by recent acquisition of high-resolution potential field and seismic data. Naturally, the major contributor to the lithospheric stress distribution is the gravitational potential energy (GPE). The study tries to incorporate available geological and geophysical data to build reliable GPE. In particular, we use the recently developed integrated gravity inversion for crustal thickness which incorporates up-to-date compilations of gravity anomalies, bathymetry, and sedimentary thickness. The modelled lithosphere thermal structure assumes a pure shear extension and the ocean age model constrained by global plate kinematics for the last ca. 120 Ma. The results of this approach are juxtaposed with estimates of the density variation inferred from the upper mantle S-wave velocity models based on previous surface wave tomography studies. Although new data and interpretations of the Arctic lithosphere structure become available now, there are areas of low accuracy or even lack of data. To compensate for this, we compare two approaches to constrain GPE: (1) one that directly integrates density of modelled lithosphere and (2) one that uses geoid anomalies which are filtered to account for density variations down to the base of the lithosphere only. The two versions of GPE compared to each other and the stresses calculated numerically are compared with observations. That allows us to optimize GPE and understand density structure, stress pattern, and factors controlling the stresses in Arctic.
Modelling spatial density using continuous wavelet transforms
Indian Academy of Sciences (India)
D Sudheer Reddy; N Gopal Reddy; A K Anilkumar
2013-02-01
Due to increase in the satelite launch activities from many countries around the world the orbital debris issue has become a major concern for the space agencies to plan a collision-free orbit design. The risk of collisions is calculated using the in situ measurements and available models. Spatial density models are useful in understanding the long-term likelihood of a collision in a particular region of space and also helpful in pre-launch orbit planning. In this paper, we present a method of estimating model parameters such as number of peaks and peak locations of spatial density model using continuous wavelets. The proposed methodology was experimented with two line element data and the results are presented.
Theory and Modeling of Phase Transformations under Stress in Steel
Institute of Scientific and Technical Information of China (English)
T.Y. Hsu (XU Zu-yao)
2004-01-01
Thermodynamic prediction of the increment of the formation temperature of proeutectoid ferrite by applied stress is nearly consistent with the experimental data. Kinetics models for ferrite, pearlite and bainite transformations can be shown as modified Johnson-Mehl-Avrami equation in which parameter b(σ) varies with the level of applied stress.The effects of tensile and compressive stresses on enhancement of the ferrite/pearlite and bainite transformations are discussed. The necessity and approach of modification of additivity hypothesis are introduced and the results from modified equation in which some parameters are obtained by regression of two experimental results or taken from TTT and CCT diagrams of a certain steel are superior than that from Scheil's equation. Thermodynamic calculation of Ms and nucleation kinetics equations of martensitic transformation under stress are suggested. Modeling of phase transformations under stress in ferrous alloys is briefly described.
TIME SERIES ANALYSIS USING A UNIQUE MODEL OF TRANSFORMATION
Directory of Open Access Journals (Sweden)
Goran Klepac
2007-12-01
Full Text Available REFII1 model is an authorial mathematical model for time series data mining. The main purpose of that model is to automate time series analysis, through a unique transformation model of time series. An advantage of this approach of time series analysis is the linkage of different methods for time series analysis, linking traditional data mining tools in time series, and constructing new algorithms for analyzing time series. It is worth mentioning that REFII model is not a closed system, which means that we have a finite set of methods. At first, this is a model for transformation of values of time series, which prepares data used by different sets of methods based on the same model of transformation in a domain of problem space. REFII model gives a new approach in time series analysis based on a unique model of transformation, which is a base for all kind of time series analysis. The advantage of REFII model is its possible application in many different areas such as finance, medicine, voice recognition, face recognition and text mining.
Energy Technology Data Exchange (ETDEWEB)
LACKS,S.A.
2003-10-09
Transformation, which alters the genetic makeup of an individual, is a concept that intrigues the human imagination. In Streptococcus pneumoniae such transformation was first demonstrated. Perhaps our fascination with genetics derived from our ancestors observing their own progeny, with its retention and assortment of parental traits, but such interest must have been accelerated after the dawn of agriculture. It was in pea plants that Gregor Mendel in the late 1800s examined inherited traits and found them to be determined by physical elements, or genes, passed from parents to progeny. In our day, the material basis of these genetic determinants was revealed to be DNA by the lowly bacteria, in particular, the pneumococcus. For this species, transformation by free DNA is a sexual process that enables cells to sport new combinations of genes and traits. Genetic transformation of the type found in S. pneumoniae occurs naturally in many species of bacteria (70), but, initially only a few other transformable species were found, namely, Haemophilus influenzae, Neisseria meningitides, Neisseria gonorrheae, and Bacillus subtilis (96). Natural transformation, which requires a set of genes evolved for the purpose, contrasts with artificial transformation, which is accomplished by shocking cells either electrically, as in electroporation, or by ionic and temperature shifts. Although such artificial treatments can introduce very small amounts of DNA into virtually any type of cell, the amounts introduced by natural transformation are a million-fold greater, and S. pneumoniae can take up as much as 10% of its cellular DNA content (40).
DEFF Research Database (Denmark)
Peters, Terri
2011-01-01
Artiklen diskuterer ordet "transformation" med udgangspunkt i dels hvorledes ordet bruges i arkitektfaglig terminologi og dels med fokus på ordets potentielle indhold og egnethed i samme teminologi.......Artiklen diskuterer ordet "transformation" med udgangspunkt i dels hvorledes ordet bruges i arkitektfaglig terminologi og dels med fokus på ordets potentielle indhold og egnethed i samme teminologi....
DEFF Research Database (Denmark)
Peters, Terri
2011-01-01
Artiklen diskuterer ordet "transformation" med udgangspunkt i dels hvorledes ordet bruges i arkitektfaglig terminologi og dels med fokus på ordets potentielle indhold og egnethed i samme teminologi.......Artiklen diskuterer ordet "transformation" med udgangspunkt i dels hvorledes ordet bruges i arkitektfaglig terminologi og dels med fokus på ordets potentielle indhold og egnethed i samme teminologi....
Sundaramoorthi, Ganesh
2012-09-13
This paper presents a novel medical image registration algorithm that explicitly models the physical constraints imposed by objects or sub-structures of objects that have differing material composition and border each other, which is the case in most medical registration applications. Typical medical image registration algorithms ignore these constraints and therefore are not physically viable, and to incorporate these constraints would require prior segmentation of the image into regions of differing material composition, which is a difficult problem in itself. We present a mathematical model and algorithm for incorporating these physical constraints into registration / motion and deformation estimation that does not require a segmentation of different material regions. Our algorithm is a joint estimation of different material regions and the motion/deformation within these regions. Therefore, the segmentation of different material regions is automatically provided in addition to the image registration satisfying the physical constraints. The algorithm identifies differing material regions (sub-structures or objects) as regions where the deformation has different characteristics. We demonstrate the effectiveness of our method on the analysis of cardiac MRI which includes the detection of the left ventricle boundary and its deformation. The experimental results indicate the potential of the algorithm as an assistant tool for the quantitative analysis of cardiac functions in the diagnosis of heart disease.
New Observational Constraints to Milky Way Chemodynamical models
Chiappini, Cristina; Anders, Friedrich; Brauer, Dorothee; Boeche, Corrado; Martig, Marie
2014-01-01
Galactic Archaeology, i.e. the use of chemo-dynamical information for stellar samples covering large portions of the Milky Way to infer the dominant processes involved in its formation and evolution, is now a powerful method thanks to the large recently completed and ongoing spectroscopic surveys. It is now important to ask the right questions when analyzing and interpreting the information contained in these rich datasets. To this aim, we have developed a chemodynamical model for the Milky Way that provides quantitative predictions to be compared with the chemo-kinematical properties extracted from the stellar spectra. Three key parameters are needed to make the comparison between data and model predictions useful in order to advance in the field, namely: precise proper-motions, distances and ages. The uncertainties involved in the estimate of ages and distances for field stars are currently the main obstacles in the Galactic Archaeology method. Two important developments might change this situation in the n...
SMT-based Bounded Model Checking with Difference Logic Constraints
Bersani, Marcello M; Morzenti, Angelo; Pradella, Matteo; Rossi, Matteo; Pietro, Pierluigi San
2010-01-01
Traditional Bounded Model Checking (BMC) is based on translating the model checking problem into SAT, the Boolean satisfiability problem. This paper introduces an encoding of Linear Temporal Logic with Past operators (PLTL) into the Quantifier-Free Difference Logic with Uninterpreted Functions (QF-UFIDL). The resulting encoding is a simpler and more concise version of existing SATbased encodings, currently used in BMC. In addition, we present an extension of PLTL augmented with arithmetic relations over integers, which can express unbounded counters; as such, the extended logic is more expressive than PLTL. We introduce suitable restrictions and assumptions that are shown to make the verification problem for the extended logic decidable, and we define an encoding of the new logic into QF-UFIDL. Finally, a performance comparison with the SAT-based approach on purely PLTL examples shows significant improvements in terms of both execution time and memory occupation.
Standard Model in multi-scale theories and observational constraints
Calcagni, Gianluca; Rodríguez-Fernández, David
2015-01-01
We construct and analyze the Standard Model of electroweak and strong interactions in multi-scale spacetimes with (i) weighted derivatives and (ii) $q$-derivatives. Both theories can be formulated in two different frames, called fractional and integer picture. By definition, the fractional picture is where physical predictions should be made. (i) In the theory with weighted derivatives, it is shown that gauge invariance and the requirement of having constant masses in all reference frames make the Standard Model in the integer picture indistinguishable from the ordinary one. Experiments involving only weak and strong forces are insensitive to a change of spacetime dimensionality also in the fractional picture, and only the electromagnetic and gravitational sectors can break the degeneracy. For the simplest multi-scale measures with only one characteristic time, length and energy scale $t_*$, $\\ell_*$ and $E_*$, we compute the Lamb shift in the hydrogen atom and constrain the multi-scale correction to the ordi...
Constraints on cosmological models from lens redshift data
Cao, Shuo
2011-01-01
Strong lensing has developed into an important astrophysical tool for probing both cosmology and galaxies (their structures, formations, and evolutions). Now several hundreds of strong lens systems produced by massive galaxies have been discovered, which may form well-defined samples useful for statistical analyses. To collect a relatively complete lens redshift data from various large systematic surveys of gravitationally lensed quasars and check the possibility to use it as a future complementarity to other cosmological probes. We use the distribution of gravitationally-lensed image separations observed in the Cosmic Lens All-Sky Survey (CLASS), the PMN-NVSS Extragalactic Lens Survey (PANELS), the Sloan Digital Sky Survey (SDSS) and other surveys, considering a singular isothermal ellipsoid (SIE) model for galactic potentials as well as improved new measurements of the velocity dispersion function of galaxies based on the SDSS DR5 data and recent semi-analytical modeling of galaxy formation, to constrain tw...
Updated scalar sector constraints in Higgs triplet model
Das, Dipankar
2016-01-01
We show that in the Higgs triplet model, after the Higgs discovery, the mixing angle in the CP-even sector can be strongly constrained from unitarity. We also discuss how large quantum effects in $h\\to\\gamma\\gamma$ may arise in a SM-like scenario and a certain part of the parameter space can be ruled out from the diphoton signal strength. Using $T$-parameter and diphoton signal strength measurements, we update the bounds on the nonstandard scalar masses.
Theoretical Model of Transformation Superlastic Diffusion Bonding for Eutectoid Steel
Institute of Scientific and Technical Information of China (English)
无
2002-01-01
Based on current theories of diffusion and creep cavity closure at high temperature, a theoretical analysis of phase transformation diffusion bonding for T8/T8 eutectoid steel is carried out. The diffusion bonding is mainly described as two-stage process: Ⅰ The interfacial cavity with shape change from diamond to cylinder.Ⅱ The radius of the cylindrical cavity are reduced and eliminated gradually. A new theoretical model is established for the process of transformation superplastic diffusion bonding (TSDB) ...
Energy Technology Data Exchange (ETDEWEB)
Chen Hao, E-mail: hao.chen@tudelft.nl [Faculty of Aerospace Engineering, Delft University of Technology, Kluyverweg 1, 2629 HS Delft (Netherlands); Appolaire, Benoit [LEM, CNRS/ONERA, 29 Av. Division Leclerc, BP 72, F-92322 Chatillon Cedex (France); Zwaag, Sybrand van der [Faculty of Aerospace Engineering, Delft University of Technology, Kluyverweg 1, 2629 HS Delft (Netherlands)
2011-10-15
A series of cyclic partial phase transformation experiments has been performed to investigate the growth kinetics of the austenite to ferrite phase transformation, and vice versa, in Fe-Mn-C alloys. Unlike the usual phase transformation experiments (100% parent phase {yields} 100% new phase), in the case of cyclic partial transformations two special stages are observed: a stagnant stage in which the degree of transformation does not vary while the temperature changes, and an inverse phase transformation stage, during which the phase transformation proceeds in a direction contradictory to the temperature change. The experimental results have been analyzed using paraequilibrium and local equilibrium diffusional growth models. Only the local equilibrium model was shown to predict the new features of the cyclic phase transformation kinetics. The stagnant stage was found to be due to Mn partitioning, while the inverse phase transformation is caused by non-equilibrium conditions when switching from cooling to heating and vice versa.
Models for thermal and mechanical monitoring of power transformers
Energy Technology Data Exchange (ETDEWEB)
Vilaithong, Rummiya
2011-07-01
At present, for economic reasons, there is an increasing emphasis on keeping transformers in service for longer than in the past. A condition-based maintenance using an online monitoring and diagnostic system is one option to ensure reliability of the transformer operation. The key parameters for effectively monitoring equipment can be selected by failure statistics and estimated failure consequences. In this work, two key aspects of transformer condition monitoring are addressed in depth: thermal behaviour and behaviour of on-load tap changers. In the first part of the work, transformer thermal behaviour is studied, focussing on top-oil temperatures. Through online comparison of a measured value of the top-oil temperature and its calculated value, some rapidly developing failures in power transformers such as malfunction of the cooling unit may be detected. Predictions of top-oil temperature can be obtained by means of a mathematical model. Long-term investigations on some dynamic top-oil temperature models are presented for three different types of transformer units. The last-state top-oil temperature, load current, ambient temperature and the operating state of pumps and fans are applied as inputs of the top-oil temperature models. In the fundamental physical models presented, some constant parameters are required and can be estimated using a least-squares optimization technique. Multilayer Feed-forward and Recurrent neural network models are also proposed and investigated. The neural network models are trained with three different Backpropagation training algorithms: Levenberg-Marquardt, Scaled Conjugate Gradient and Automated Bayesian Regularization. The effect of varying operating conditions of the cooling units and the non-steady-state behaviour of loading conditions, as well as ambient temperature are noted. Results show sophisticated temperature prediction is possible using the neural network models that is generally more accurate than with the physical
Indirect detection constraints on the model space of dark matter effective theories
Carpenter, Linda M.; Colburn, Russell; Goodman, Jessica
2015-11-01
Using limits on photon flux from dwarf spheroidal galaxies, we place bounds on the parameter space of models in which dark matter annihilates into multiple final state particle pair channels. We derive constraints on effective operator models with dark matter couplings to third generation fermions and to pairs of standard model vector bosons. We present limits in various slices of model parameter space along with estimations of the region of maximal validity of the effective operator approach for indirect detection. We visualize our bounds for models with multiple final state annihilations by projecting parameter space constraints onto triangles, a technique familiar from collider physics; and we compare our bounds to collider limits on equivalent models.
Indirect Detection Constraints on the Model Space of Dark Matter Effective Theories
Carpenter, Linda M; Goodman, Jessica
2015-01-01
Using limits on photon flux from Dwarf Spheroidal galaxies, we place bounds on the parameter space of models in which Dark Matter annihilates into multiple final state particle pair channels. We derive constraints on effective operator models with Dark Matter couplings to third generation fermions and to pairs of Standard Model vector bosons. We present limits in various slices of model parameter space along with estimations of the region of maximal validity of the effective operator approach for indirect detection. We visualize our bounds for models with multiple final state annihilations by projecting parameter space constraints onto triangles, a technique familiar from collider physics; and we compare our bounds to collider limits on equivalent models.
Physical Constraint Finite Element Model for Medical Image Registration.
Directory of Open Access Journals (Sweden)
Jingya Zhang
Full Text Available Due to being derived from linear assumption, most elastic body based non-rigid image registration algorithms are facing challenges for soft tissues with complex nonlinear behavior and with large deformations. To take into account the geometric nonlinearity of soft tissues, we propose a registration algorithm on the basis of Newtonian differential equation. The material behavior of soft tissues is modeled as St. Venant-Kirchhoff elasticity, and the nonlinearity of the continuum represents the quadratic term of the deformation gradient under the Green- St.Venant strain. In our algorithm, the elastic force is formulated as the derivative of the deformation energy with respect to the nodal displacement vectors of the finite element; the external force is determined by the registration similarity gradient flow which drives the floating image deforming to the equilibrium condition. We compared our approach to three other models: 1 the conventional linear elastic finite element model (FEM; 2 the dynamic elastic FEM; 3 the robust block matching (RBM method. The registration accuracy was measured using three similarities: MSD (Mean Square Difference, NC (Normalized Correlation and NMI (Normalized Mutual Information, and was also measured using the mean and max distance between the ground seeds and corresponding ones after registration. We validated our method on 60 image pairs including 30 medical image pairs with artificial deformation and 30 clinical image pairs for both the chest chemotherapy treatment in different periods and brain MRI normalization. Our method achieved a distance error of 0.320±0.138 mm in x direction and 0.326±0.111 mm in y direction, MSD of 41.96±13.74, NC of 0.9958±0.0019, NMI of 1.2962±0.0114 for images with large artificial deformations; and average NC of 0.9622±0.008 and NMI of 1.2764±0.0089 for the real clinical cases. Student's t-test demonstrated that our model statistically outperformed the other methods in
The Transformation of the Getzels Model.
McPherson, R. Bruce
The author describes the model of social behavior in a social system first framed by Jacob Getzels, with the assistance of Egon Guba, in the middle 1950s. Significant changes in the conceptualization of organizational functioning have occurred in the years since then, though the methodological processes for studying that functioning have remained…
Standard Model in multiscale theories and observational constraints
Calcagni, Gianluca; Nardelli, Giuseppe; Rodríguez-Fernández, David
2016-08-01
We construct and analyze the Standard Model of electroweak and strong interactions in multiscale spacetimes with (i) weighted derivatives and (ii) q -derivatives. Both theories can be formulated in two different frames, called fractional and integer picture. By definition, the fractional picture is where physical predictions should be made. (i) In the theory with weighted derivatives, it is shown that gauge invariance and the requirement of having constant masses in all reference frames make the Standard Model in the integer picture indistinguishable from the ordinary one. Experiments involving only weak and strong forces are insensitive to a change of spacetime dimensionality also in the fractional picture, and only the electromagnetic and gravitational sectors can break the degeneracy. For the simplest multiscale measures with only one characteristic time, length and energy scale t*, ℓ* and E*, we compute the Lamb shift in the hydrogen atom and constrain the multiscale correction to the ordinary result, getting the absolute upper bound t*28 TeV . Stronger bounds are obtained from the measurement of the fine-structure constant. (ii) In the theory with q -derivatives, considering the muon decay rate and the Lamb shift in light atoms, we obtain the independent absolute upper bounds t*35 MeV . For α0=1 /2 , the Lamb shift alone yields t*450 GeV .
Cosmological constraints on non-standard inflationary quantum collapse models
Landau, Susana J; Sudarsky, Daniel
2011-01-01
We briefly review an important shortcoming --unearthed in previous works-- of the standard version of the inflationary model for the emergence of the seeds of cosmic structure. We consider here some consequences emerging from a proposal inspired on ideas of Penrose and Di\\'osi about a quantum-gravity induced reduction of the wave function, which has been put forward to address the shortcomings, arguing that its effect on the inflaton field is what can lead to the emergence of the seeds of cosmic structure. The proposal leads to a deviation of the primordial spectrum from the scale-invariant Harrison-Zel'dovich one, and consequently, to a different CMB power spectrum. We perform statistical analyses to test two quantum collapse schemes with recent data from the CMB, including the 7-yr release of WMAP and the matter power spectrum measured using LRGs by the Sloan Digital Sky Survey. Results from the statistical analyses indicate that several collapse models are compatible with CMB and LRG data, and establish co...
The Unfolding of Value Sources During Online Business Model Transformation
Directory of Open Access Journals (Sweden)
Nadja Hoßbach
2016-12-01
Full Text Available Purpose: In the magazine publishing industry, viable online business models are still rare to absent. To prepare for the ‘digital future’ and safeguard their long-term survival, many publishers are currently in the process of transforming their online business model. Against this backdrop, this study aims to develop a deeper understanding of (1 how the different building blocks of an online business model are transformed over time and (2 how sources of value creation unfold during this transformation process. Methodology: To answer our research question, we conducted a longitudinal case study with a leading German business magazine publisher (called BIZ. Data was triangulated from multiple sources including interviews, internal documents, and direct observations. Findings: Based on our case study, we nd that BIZ used the transformation process to differentiate its online business model from its traditional print business model along several dimensions, and that BIZ’s online business model changed from an efficiency- to a complementarity- to a novelty-based model during this process. Research implications: Our findings suggest that different business model transformation phases relate to different value sources, questioning the appropriateness of value source-based approaches for classifying business models. Practical implications: The results of our case study highlight the need for online-offline business model differentiation and point to the important distinction between service and product differentiation. Originality: Our study contributes to the business model literature by applying a dynamic and holistic perspective on the link between online business model changes and unfolding value sources.
Constraints on the $\\Lambda$CDM model with redshift tomography
Cai, Rong-Gen; Tang, Bo
2013-01-01
Recently released Planck data favor a lower value of the Hubble constant and a higher value of the fraction matter density in the standard $\\Lambda$CDM model, which are discrepant with some of the low-redshift measurements. Within the context of this cosmology, we examine the consistency of the estimated values for the Hubble constant and fraction matter density with redshift tomography. Using the SNe Ia, Hubble parameter, BAO and CMB data, which are divided into three bins, we find no statistical evidence for any tension in the three redshift bins, although there exists a 1.4$\\sigma$ deviation of the Hubble constant in the middle redshift from the one in the high redshift bin.
Constraints on cosmological models from strong gravitational lensing systems
Cao, Shuo; Biesiada, Marek; Godlowski, Wlodzimierz; Zhu, Zong-Hong
2011-01-01
Using the gravitational lensing theory and cluster mass distribution model, we try to collect a relatively complete observational data concerning an Hubble constant independent ratio between two angular diameter distances $D_{ds}/D_s$ from various large systematic gravitational lens surveys and lensing by galaxy clusters combined with X-ray observations. On one hand, strongly gravitationally lensed quasar-galaxy systems create such a new opportunity by combining stellar kinematics (central velocity dispersion measurements) with lensing geometry (Einstein radius determination from position of images). We apply such a method to a combined gravitational lens data set including 27 data points from Sloan Lens ACS (SLACS), Lens Structure and Dynamics survey (LSD), and Sloan Bright Arcs Survey (SBAS). On the other hand, a new sample of 10 lensing galaxy clusters with redshifts ranging from 0.1 to 0.6 is also used, which is selected carefully from strong gravitational lensing systems with both X-ray satellite observa...
Baker, W.R.
1959-08-25
Transformers of a type adapted for use with extreme high power vacuum tubes where current requirements may be of the order of 2,000 to 200,000 amperes are described. The transformer casing has the form of a re-entrant section being extended through an opening in one end of the cylinder to form a coaxial terminal arrangement. A toroidal multi-turn primary winding is disposed within the casing in coaxial relationship therein. In a second embodiment, means are provided for forming the casing as a multi-turn secondary. The transformer is characterized by minimized resistance heating, minimized external magnetic flux, and an economical construction.
New Constraints on the Unified Model of Seyfert Galaxies
Maiolino, R.; Ruiz, M.; Rieke, G. H.; Keller, L. D.
1995-06-01
We present new 10 microns (N-band) photometry for 70 Seyfert galaxies, 43 of them previously unobserved. These observations, together with those collected from the literature, complete the 10 microns photometry for the CfA Sy galaxies and cover 80% of the Sy found in the RSA and 70% of the Sy in the IRAS 12 microns sample. From this data set, we find that Sy not showing any evidence for broad lines are systematically weaker in 10 microns nuclear emission than Sy nuclei having broad lines. This result may indicate the existence of a group of very low-luminosity Sy2 galaxies that do not have Sy1 counterparts in equal numbers, contrary to the strict unified theory. Alternately, the result can be reconciled with unified theories if a specific type of geometry is assumed for the circumnuclear obscuring material. By comparing the 10 microns ground-based observations with the IRAS 12 microns fluxes, we also study the properties of the extended mid-IR emission, i.e., the star forming activity of the host galaxy of the Sy nucleus. We find Sy2 to lie preferentially in galaxies experiencing enhanced star-forming activity, while Sy1 lie in normal or quiescent galaxies. This result appears to be inconsistent with the strict unified model, since the host galaxy properties should be independent of the orientation of a circumnuclear torus and therefore should be independent of nuclear type. Our finding could be explained by adding to the unified model a link between star-forming activity and the amount of obscuring material collected in the circumnuclear region.
Modelling and Simulation of the Diode Split Transformer
DEFF Research Database (Denmark)
Østergaard, Leo
a significant influence on the picture quality. The most critical component is undoubtedly the diode split transformer (DST). Therefore, if developing a simulation model of the DST is possible, a significant step has been taken in the attempt to model the entire horizontal deflection circuit and to obtain...
A Model To Address Design Constraints of Training Delivered via Satellite. Study Number Eight.
Montler, Joseph; Geroy, Gary D.
This document: summarizes how some companies are addressing the design constraints involved in using satellite technology to deliver training, presents a model aimed at examining cost effectiveness of the satellite option, and includes a guide to designing instructional materials for delivery by satellite. A survey of 39 organizations, 12…
Constraints on model atmospheres from complex asteroseismology of the \\beta Cephei stars
Szewczuk, Wojciech; Daszyńska-Daszkiewicz, Jadwiga
2012-01-01
Using the method termed complex asteroseismology, we derive constraints on model atmospheres, in particular, on the NLTE effects. We fit simultaneously pulsational frequencies and the corresponding values of the nonadiabatic complex parameter f for the four \\beta Cephei stars: \\theta Oph, \
Constraint-Based Modeling: From Cognitive Theory to Computer Tutoring--and Back Again
Ohlsson, Stellan
2016-01-01
The ideas behind the constraint-based modeling (CBM) approach to the design of intelligent tutoring systems (ITSs) grew out of attempts in the 1980's to clarify how declarative and procedural knowledge interact during skill acquisition. The learning theory that underpins CBM was based on two conceptual innovations. The first innovation was to…
Using Online Modelled Spatial Constraints for Pose Estimation in an Industrial Setting
DEFF Research Database (Denmark)
Meyer, Kenneth Korsgaard; Wolniakowski, Adam; Hagelskjær, Frederik;
2017-01-01
We introduce a vision system that is able to on-line learn spatial constraints to improve pose estimation in terms of correct recognition as well as computational speed. By making use of a simulated industrial robot system performing various pick and place tasks, we show the effect of model...
A note on a model for quay crane scheduling with non-crossing constraints
DEFF Research Database (Denmark)
Santini, Alberto; Friberg, Henrik Alsing; Røpke, Stefan
2015-01-01
This article studies the quay crane scheduling problem with non-crossing constraints, which is an operational problem that arises in container terminals. An enhancement to a mixed integer programming model for the problem is proposed and a new class of valid inequalities is introduced. Computatio...
Jarosz, Gaja
2010-01-01
This study examines the interacting roles of implicational markedness and frequency from the joint perspectives of formal linguistic theory, phonological acquisition and computational modeling. The hypothesis that child grammars are rankings of universal constraints, as in Optimality Theory (Prince & Smolensky, 1993/2004), that learning involves a…
How robust are inflation model and dark matter constraints from cosmological data?
Energy Technology Data Exchange (ETDEWEB)
Hamann, J. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Hannestad, S.; Sloth, M.S. [Aarhus Univ. (Denmark). Dept. of Physics and Astronomy; Wong, Y.Y.Y. [Max-Planck-Institut fuer Physik, Muenchen (Germany). Werner-Heisenberg-Institut
2006-11-15
High-precision data from observation of the cosmic microwave background and the large scale structure of the universe provide very tight constraints on the effective parameters that describe cosmological inflation. Indeed, within a constrained class of {lambda}CDM models, the simple {lambda}{phi}{sup 4} chaotic inflation model already appears to be ruled out by cosmological data. In this paper, we compute constraints on inflationary parameters within a more general framework that includes other physically motivated parameters such as a nonzero neutrino mass. We find that a strong degeneracy between the tensor-to-scalar ratio {tau} and the neutrino mass prevents {lambda}{phi}{sup 4} from being excluded by present data. Reversing the argument, if {lambda}{phi}{sup 4} is the correct model of inflation, it predicts a sum of neutrino masses at 0.3{yields}0.5 eV, a range compatible with present experimental limits and within the reach of the next generation of neutrino mass measurements. We also discuss the associated constraints on the dark matter density, the dark energy equation of state, and spatial curvature, and show that the allowed regions are significantly altered. Importantly, we find an allowed range of 0.094<{omega}{sub c}h{sup 2}<0.136 for the dark matter density, a factor of two larger than that reported in previous studies. This expanded parameter space may have implications for constraints on SUSY dark matter models. (orig.)
Model refinements of transformers via a subproblem finite element method
Dular, Patrick; Kuo-Peng, Patrick; Ferreira Da Luz, Mauricio,; Krähenbühl, Laurent
2015-01-01
International audience; A progressive modeling of transformers is performed via a subproblem finite element method. A complete problem is split into subproblems with different adapted overlapping meshes. Model refinements are performed from ideal to real flux tubes, 1-D to 2-D to 3-D models, linear to nonlinear materials, perfect to real materials, single wire to volume conductor windings, and homogenized to fine models of cores and coils, with any coupling of these changes. The proposed unif...
Cash-In-Advance Constraints in a Schumpeterian Growth Model with an Endogenous Market Structure
Chien-Yu Huang; Juin-Jen Chang; Lei Ji
2013-01-01
This paper explores the macro effects of monetary policy in a Schumpeterian growth model with an endogenous market structure and distinct cash-in-advance (CIA) constraints on consumption, production, and two distinct types of R&D investment - in-house R&D and entry investment. We show that the CIA constraints work through various channels and the effects of monetary policy depend on the strength of each channel. Although ination seems like a uniform tax imposed on the whole economy, an identi...
PNe as observational constraints in chemical evolution models for NGC 6822
Hernandez-Martinez, Liliana; Peña, Miriam; Peimbert, Manuel
2011-01-01
Chemical evolution models are useful for understanding the formation and evolution of stars and galaxies. Model predictions will be more robust as more observational constraints are used. We present chemical evolution models for the dwarf irregular galaxy NGC 6822 using chemical abundances of old and young Planetary Nebulae (PNe) and \\ion{H}{ii} regions as observational constraints. Two sets of chemical abundances, one derived from collisionally excited lines (CELs) and one, from recombination lines (RLs), are used. We try to use our models as a tool to discriminate between both procedures for abundance determinations. In our chemical evolution code, the chemical contribution of low and intermediate mass stars is time delayed, while for the massive stars the chemical contribution follows the instantaneous recycling approximation. Our models have two main free parameters: the mass-loss rate of a well-mixed outflow and the upper mass limit, $M_{up}$, of the initial mass function (IMF). To reproduce the gaseous ...
Phase Field Models for Thin Elastic Structures with Topological Constraint
Dondl, Patrick W.; Lemenant, Antoine; Wojtowytsch, Stephan
2017-02-01
This article is concerned with the problem of minimising the Willmore energy in the class of connected surfaces with prescribed area which are confined to a small container. We propose a phase field approximation based on De Giorgi's diffuse Willmore functional to this variational problem. Our main contribution is a penalisation term which ensures connectedness in the sharp interface limit. The penalisation of disconnectedness is based on a geodesic distance chosen to be small between two points that lie on the same connected component of the transition layer of the phase field. We prove that in two dimensions, sequences of phase fields with uniformly bounded diffuse Willmore energy and diffuse area converge uniformly to the zeros of a double-well potential away from the support of a limiting measure. In three dimensions, we show that they converge H^1-almost everywhere on curves. This enables us to show {Γ}-convergence to a sharp interface problem that only allows for connected structures. The results also imply Hausdorff convergence of the level sets in two dimensions and a similar result in three dimensions. Furthermore, we present numerical evidence of the effectiveness of our model. The implementation relies on a coupling of Dijkstra's algorithm in order to compute the topological penalty to a finite element approach for the Willmore term.
Econometric Based Modeling of Population Growth under Socio-cultual Constraints
Ausloos, Marcel; Herteliu, Claudiu; Ileanu, Bogdan Vasile
2015-01-01
There are many constraints on population growth or decay in a country: several are of socio-economic origins. Sometimes cultual constraints also exist: sexual intercourse is banned in various religions, during Nativity and Lent fasting periods. We analyzed data consisting of registered daily birth records for very long (35,429 points) time series and many (24,947,061) babies in Romania between 1905 and 2001 (97 years). The data was obtained from the 1992 and 2002 censuses. We grouped the population into two categories (Eastern Orthodox and Non-Orthodox) in order to distinguish cultual constraints. We performed extensive data analysis in a comparative manner for both groups. From such a long time series data analysis, it seems that the Lent fast has a more drastic effect than the Nativity fast over baby conception within the Eastern Orthodox population, thereby differently increasing the population ratio. Thereafter, we developed and tested econometric models where the dependent variable is the baby conception...
Battat, James B R; Chandler, John F; Stubbs, Christopher W
2007-12-14
We present constraints on violations of Lorentz invariance based on archival lunar laser-ranging (LLR) data. LLR measures the Earth-Moon separation by timing the round-trip travel of light between the two bodies and is currently accurate to the equivalent of a few centimeters (parts in 10(11) of the total distance). By analyzing this LLR data under the standard-model extension (SME) framework, we derived six observational constraints on dimensionless SME parameters that describe potential Lorentz violation. We found no evidence for Lorentz violation at the 10(-6) to 10(-11) level in these parameters. This work constitutes the first LLR constraints on SME parameters.
Convergence Guaranteed Nonlinear Constraint Model Predictive Control via I/O Linearization
Directory of Open Access Journals (Sweden)
Xiaobing Kong
2013-01-01
Full Text Available Constituting reliable optimal solution is a key issue for the nonlinear constrained model predictive control. Input-output feedback linearization is a popular method in nonlinear control. By using an input-output feedback linearizing controller, the original linear input constraints will change to nonlinear constraints and sometimes the constraints are state dependent. This paper presents an iterative quadratic program (IQP routine on the continuous-time system. To guarantee its convergence, another iterative approach is incorporated. The proposed algorithm can reach a feasible solution over the entire prediction horizon. Simulation results on both a numerical example and the continuous stirred tank reactors (CSTR demonstrate the effectiveness of the proposed method.
Coupling Phonology and Phonetics in a Constraint-Based Gestural Model
Walther, M; Walther, Markus; Kroeger, Bernd J.
1994-01-01
An implemented approach which couples a constraint-based phonology component with an articulatory speech synthesizer is proposed. Articulatory gestures ensure a tight connection between both components, as they comprise both physical-phonetic and phonological aspects. The phonological modelling of e.g. syllabification and phonological processes such as German final devoicing is expressed in the constraint logic programming language CUF. Extending CUF by arithmetic constraints allows the simultaneous description of both phonology and phonetics. Thus declarative lexicalist theories of grammar such as HPSG may be enriched up to the level of detailed phonetic realisation. Initial acoustic demonstrations show that our approach is in principle capable of synthesizing full utterances in a linguistically motivated fashion.
Transformative leadership: an ethical stewardship model for healthcare.
Caldwell, Cam; Voelker, Carolyn; Dixon, Rolf D; LeJeune, Adena
2008-01-01
The need for effective leadership is a compelling priority for those who would choose to govern in public, private, and nonprofit organizations, and applies as much to the healthcare profession as it does to other sectors of the economy (Moody, Horton-Deutsch, & Pesut, 2007). Transformative Leadership, an approach to leadership and governance that incorporates the best characteristics of six other highly respected leadership models, is an integrative theory of ethical stewardship that can help healthcare professionals to more effectively achieve organizational efficiencies, build stakeholder commitment and trust, and create valuable synergies to transform and enrich today's healthcare systems (cf. Caldwell, LeJeune, & Dixon, 2007). The purpose of this article is to introduce the concept of Transformative Leadership and to explain how this model applies within a healthcare context. We define Transformative Leadership and identify its relationship to Transformational, Charismatic, Level 5, Principle-Centered, Servant, and Covenantal Leadership--providing examples of each of these elements of Transformative Leadership within a healthcare leadership context. We conclude by identifying contributions of this article to the healthcare leadership literature.
Transform Coding for Point Clouds Using a Gaussian Process Model.
De Queiroz, Ricardo; Chou, Philip A
2017-04-28
We propose using stationary Gaussian Processes (GPs) to model the statistics of the signal on points in a point cloud, which can be considered samples of a GP at the positions of the points. Further, we propose using Gaussian Process Transforms (GPTs), which are Karhunen-Lo`eve transforms of the GP, as the basis of transform coding of the signal. Focusing on colored 3D point clouds, we propose a transform coder that breaks the point cloud into blocks, transforms the blocks using GPTs, and entropy codes the quantized coefficients. The GPT for each block is derived from both the covariance function of the GP and the locations of the points in the block, which are separately encoded. The covariance function of the GP is parameterized, and its parameters are sent as side information. The quantized coefficients are sorted by eigenvalues of the GPTs, binned, and encoded using an arithmetic coder with bin-dependent Laplacian models whose parameters are also sent as side information. Results indicate that transform coding of 3D point cloud colors using the proposed GPT and entropy coding achieves superior compression performance on most of our data sets.
Transformer real-time reliability model based on operating conditions
Institute of Scientific and Technical Information of China (English)
HE Jian; CHENG Lin; SUN Yuan-zhang
2007-01-01
Operational reliability evaluation theory reflects real-time reliability level of power system. The component failure rate varies with operating conditions. The impact of real-time operating conditions such as ambient temperature and transformer MVA (megavolt-ampere) loading on transformer insulation life is studied in this paper. The formula of transformer failure rate based on the winding hottest-spot temperature (HST) is given. Thus the real-time reliability model of transformer based on operating conditions is presented. The work is illustrated using the 1979 IEEE Reliability Test System. The changes of operating conditions are simulated by using hourly load curve and temperature curve, so the curves of real-time reliability indices are obtained by using operational reliability evaluation.
Semiparametric Additive Transformation Model under Current Status Data
Cheng, Guang
2011-01-01
We consider the efficient estimation of the semiparametric additive transformation model with current status data. A wide range of survival models and econometric models can be incorporated into this general transformation framework. We apply the B-spline approach to simultaneously estimate the linear regression vector, the nondecreasing transformation function, and a set of nonparametric regression functions. We show that the parametric estimate is semiparametric efficient in the presence of multiple nonparametric nuisance functions. An explicit consistent B-spline estimate of the asymptotic variance is also provided. All nonparametric estimates are smooth, and shown to be uniformly consistent and have faster than cubic rate of convergence. Interestingly, we observe the convergence rate interfere phenomenon, i.e., the convergence rates of B-spline estimators are all slowed down to equal the slowest one. The constrained optimization is not required in our implementation. Numerical results are used to illustra...
A TRANSFORMATION APPROACH FOR COLLABORATION BASED REQUIREMENT MODELS
Directory of Open Access Journals (Sweden)
Ahmed Harbouche
2012-02-01
Full Text Available Distributed software engineering is widely recognized as a complex task. Among the inherent complexitiesis the process of obtaining a system design from its global requirement specification. This paper deals withsuch transformation process and suggests an approach to derive the behavior of a given systemcomponents, in the form of distributed Finite State Machines, from the global system requirements, in theform of an augmented UML Activity Diagrams notation. The process of the suggested approach issummarized in three steps: the definition of the appropriate source Meta-Model (requirements Meta-Model, the definition of the target Design Meta-Model and the definition of the rules to govern thetransformation during the derivation process. The derivation process transforms the global systemrequirements described as UML diagram activities (extended with collaborations to system rolesbehaviors represented as UML finite state machines. The approach is implemented using AtlasTransformation Language (ATL.
The localization and correction of errors in models: a constraint-based approach
Piechowiak, S.; Rodriguez, J
2005-01-01
Model-based diagnosis, and constraint-based reasoning are well known generic paradigms for which the most difficult task lies in the construction of the models used. We consider the problem of localizing and correcting the errors in a model.We present a method to debug a model. To help the debugging task, we propose to use the model-base diagnosis solver. This method has been used in a real application of the development a model of a railway signalling system.
Transfer Function Identification Using Orthogonal Fourier Transform Modeling Functions
Morelli, Eugene A.
2013-01-01
A method for transfer function identification, including both model structure determination and parameter estimation, was developed and demonstrated. The approach uses orthogonal modeling functions generated from frequency domain data obtained by Fourier transformation of time series data. The method was applied to simulation data to identify continuous-time transfer function models and unsteady aerodynamic models. Model fit error, estimated model parameters, and the associated uncertainties were used to show the effectiveness of the method for identifying accurate transfer function models from noisy data.
Cosmological Constraints on Radion Evolution in the Universal Extra Dimension Model
Chan, K C
2007-01-01
The constraints on the radion evolution in the Universal Extra Dimension (UED) model from Cosmic Microwave Background (CMB) and Type Ia supernovae (SNe Ia) data are studied. In the UED model, where both the gravity and standard model fields can propagate in the extra dimensions, the evolution of the extra dimensional volume, the radion, induces variation of fundamental constants. We discuss the effects of variation of the relevant constants in the context of UED for CMB power spectrum and SNe Ia data. We then use the three-year WMAP data to constrain the radion evolution at z \\sim 1100, and the 2 \\sigma constraint on \\dot{\\rho} / \\rho_0 (\\rho is a function of the radion, to be defined in the text) is [ -8.8, 6.6] \\times 10 ^{-13} yr^-1. The SNe Ia gold sample yields a constraint on \\dot{\\rho} / \\rho_0, for redshift between 0 and 1, to be [-4.7, 14] \\times 10^{-13} yr^-1. Furthermore, the constraints from SNe Ia can be interpreted as bounds on the evolution QCD scale parameter, \\dot{\\Lambda}_{QCD} / \\Lambda_{Q...
Digital terrain model generalization incorporating scale, semantic and cognitive constraints
Partsinevelos, Panagiotis; Papadogiorgaki, Maria
2014-05-01
Cartographic generalization is a well-known process accommodating spatial data compression, visualization and comprehension under various scales. In the last few years, there are several international attempts to construct tangible GIS systems, forming real 3D surfaces using a vast number of mechanical parts along a matrix formation (i.e., bars, pistons, vacuums). Usually, moving bars upon a structured grid push a stretching membrane resulting in a smooth visualization for a given surface. Most of these attempts suffer either in their cost, accuracy, resolution and/or speed. Under this perspective, the present study proposes a surface generalization process that incorporates intrinsic constrains of tangible GIS systems including robotic-motor movement and surface stretching limitations. The main objective is to provide optimized visualizations of 3D digital terrain models with minimum loss of information. That is, to minimize the number of pixels in a raster dataset used to define a DTM, while reserving the surface information. This neighborhood type of pixel relations adheres to the basics of Self Organizing Map (SOM) artificial neural networks, which are often used for information abstraction since they are indicative of intrinsic statistical features contained in the input patterns and provide concise and characteristic representations. Nevertheless, SOM remains more like a black box procedure not capable to cope with possible particularities and semantics of the application at hand. E.g. for coastal monitoring applications, the near - coast areas, surrounding mountains and lakes are more important than other features and generalization should be "biased"-stratified to fulfill this requirement. Moreover, according to the application objectives, we extend the SOM algorithm to incorporate special types of information generalization by differentiating the underlying strategy based on topologic information of the objects included in the application. The final
Directory of Open Access Journals (Sweden)
Hea-Jung Kim
2017-06-01
Full Text Available This paper develops Bayesian inference in reliability of a class of scale mixtures of log-normal failure time (SMLNFT models with stochastic (or uncertain constraint in their reliability measures. The class is comprehensive and includes existing failure time (FT models (such as log-normal, log-Cauchy, and log-logistic FT models as well as new models that are robust in terms of heavy-tailed FT observations. Since classical frequency approaches to reliability analysis based on the SMLNFT model with stochastic constraint are intractable, the Bayesian method is pursued utilizing a Markov chain Monte Carlo (MCMC sampling based approach. This paper introduces a two-stage maximum entropy (MaxEnt prior, which elicits a priori uncertain constraint and develops Bayesian hierarchical SMLNFT model by using the prior. The paper also proposes an MCMC method for Bayesian inference in the SMLNFT model reliability and calls attention to properties of the MaxEnt prior that are useful for method development. Finally, two data sets are used to illustrate how the proposed methodology works.
Constraints on field theoretical models for variation of the fine structure constant
Steinhardt, Charles L.
2005-02-01
Recent theoretical ideas and observational claims suggest that the fine structure constant α may be variable. We examine a spectrum of models in which α is a function of a scalar field. Specifically, we consider three scenarios: oscillating α, monotonic time variation of α, and time-independent α that is spatially varying. We examine the constraints imposed upon these theories by cosmological observations, particle detector experiments, and “fifth force” experiments. These constraints are very strong on models involving oscillation but cannot compete with bounds from the Oklo subnuclear reactor on models with monotonic timelike variation of α. One particular model with spatial variation is consistent with all current experimental and observational measurements, including those from two seemingly conflicting measurements of the fine structure constant using the many multiplet method on absorption lines.
K-mouflage gravity models that pass Solar System and cosmological constraints
Barreira, Alexandre; Clesse, Sebastien; Li, Baojiu; Valageas, Patrick
2015-01-01
We show that Solar System tests can place very strong constraints on K-mouflage models of gravity, which are coupled scalar field models with nontrivial kinetic terms that screen the fifth force in regions of large gravitational acceleration. In particular, the bounds on the anomalous perihelion of the Moon imposes stringent restrictions on the K-mouflage Lagrangian density, which can be met when the contributions of higher order operators in the static regime are sufficiently small. The bound on the rate of change of the gravitational strength in the Solar System constrains the coupling strength $\\beta$ to be smaller than $0.1$. These two bounds impose tighter constraints than the results from the Cassini satellite and Big Bang Nucleosynthesis. Despite the Solar System restrictions, we show that it is possible to construct viable models with interesting cosmological predictions. In particular, relative to $\\Lambda$-CDM, such models predict percent level deviations for the clustering of matter and the number ...
Estimation of DSGE Models under Diffuse Priors and Data-Driven Identification Constraints
DEFF Research Database (Denmark)
Lanne, Markku; Luoto, Jani
the properties of the estimation method, and shows how the problem of multimodal posterior distributions caused by parameter redundancy is eliminated by identification constraints. Out-of-sample forecast comparisons as well as Bayes factors lend support to the constrained model.......We propose a sequential Monte Carlo (SMC) method augmented with an importance sampling step for estimation of DSGE models. In addition to being theoretically well motivated, the new method facilitates the assessment of estimation accuracy. Furthermore, in order to alleviate the problem...... of multimodal posterior distributions due to poor identification of DSGE models when uninformative prior distributions are assumed, we recommend imposing data-driven identification constraints and devise a procedure for finding them. An empirical application to the Smets-Wouters (2007) model demonstrates...
An enhanced Brinson model with modified kinetics for martensite transformation
Energy Technology Data Exchange (ETDEWEB)
Kim, Young-Jin; Lee, Jung Ju [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Jeong, Ju-Won [Korea Aerospace Research Institute, Daejeon (Korea, Republic of); Lim, Jae Hyuk [Chonbuk National University, Jeonju (Korea, Republic of)
2017-03-15
We propose an enhanced Brinson model with modified kinetics for martensite transformation. Two additional material constants are considered to follow the stress-temperature diagram above austenite start temperature (As) along with treatment to keep the continuity of the martensite volume fraction and the path dependency of the phase transformation. To demonstrate the performance of the proposed model, we implement this algorithm into ABAQUS user subroutine, then conduct several numerical simulations and compare their results with SMA wire experiments as well as those of three-dimensional SMA constitutive models. From the results, it turns out that the proposed model is as accurate as the three-dimensional models and shows better accuracy over original Brinson model in terms of recovery stress.
Ventosa, Sergi; Romanowicz, Barbara
2015-11-01
Resolving the topography of the core-mantle boundary (CMB) and the structure and composition of the D″ region is key to improving our understanding of the interaction between the Earth's mantle and core. Observations of traveltimes and amplitudes of short-period teleseismic body waves sensitive to lowermost mantle provide essential constraints on the properties of this region. Major challenges are low signal-to-noise ratio of the target phases and interference with other mantle phases. In a previous paper (Part I), we introduced the slant-stacklet transform to enhance the signal of the core-reflected (PcP) phase and to isolate it from stronger signals in the coda of the P wave. Then we minimized a linear misfit between P and PcP waveforms to improve the quality of PcP-P traveltime difference measurements as compared to standard cross-correlation methods. This method significantly increases the quantity and the quality of PcP-P traveltime observations available for the modelling of structure near the CMB. Here we illustrate our approach in a series of regional studies of the CMB and D″ using PcP-P observations with unprecedented resolution from high-quality dense arrays located in North America and Japan for events with magnitude Mw>5.4 and distances up to 80°. In this process, we carefully analyse various sources of errors and show that mantle heterogeneity is the most significant. We find and correct bias due to mantle heterogeneities that is as large as 1 s in traveltime, comparable to the largest lateral PcP-P traveltime variations observed. We illustrate the importance of accurate mantle corrections and the need for higher resolution mantle models for future studies. After optimal mantle corrections, the main signal left is relatively long wavelength in the regions sampled, except at the border of the Pacific large-low shear velocity province (LLSVP). We detect the northwest border of the Pacific LLSVP in the western Pacific from array observations in
Constraints on the generalized Chaplygin gas model from Gamma-ray bursts
Energy Technology Data Exchange (ETDEWEB)
Freitas, R.C., E-mail: rc_freitas@terra.com.br [Grupo de Gravitacao e Cosmologia, Departamento de Fisica, Universidade Federal do Espirito Santo, 29075-910, Vitoria, Espirito Santo (Brazil); Goncalves, S.V.B., E-mail: sergio.vitorino@pq.cnpq.br [Grupo de Gravitacao e Cosmologia, Departamento de Fisica, Universidade Federal do Espirito Santo, 29075-910, Vitoria, Espirito Santo (Brazil); Velten, H.E.S., E-mail: velten@cce.ufes.br [Grupo de Gravitacao e Cosmologia, Departamento de Fisica, Universidade Federal do Espirito Santo, 29075-910, Vitoria, Espirito Santo (Brazil); Fakultaet fuer Physik, Universitaet Bielefeld, Bielefeld 33615 (Germany)
2011-09-14
We study the generalized Chaplygin gas model (GCGM) using Gamma-ray bursts as cosmological probes. In order to avoid the so-called circularity problem we use cosmology-independent data set and Bayesian statistics to impose constraints on the model parameters. We observe that a negative value for the parameter {alpha} is favoured in a flat Universe and the estimated value of the parameter H{sub 0} is lower than that found in literature.
New Constraints from Electric Dipole Moments on Parameters of the Supersymmetric SO(10) Model
Khriplovich, I. B.; Zyablyuk, K. N.
1996-01-01
We calculate the chromoelectric dipole moment (CEDM) of d- and s-quark in the supersymmetric SO(10) model. CEDM is more efficient than quark electric dipole moment (EDM), in inducing the neutron EDM. New, strict constraints on parameters of the supersymmetric SO(10) model follow in this way from the neutron dipole moment experiments. As strict bounds are derived from the upper limits on the dipole moment of odd isotope of mercury.
Transformations for temperature flux in multiscale models of the tropics
Energy Technology Data Exchange (ETDEWEB)
Biello, Joseph A.; Majda, Andrew J. [New York University, Courant Institute of Mathematical Sciences, New York, NY (United States)
2006-11-15
How much of the observed planetary-scale heating in the tropics is due to eddy flux convergence? A mathematical framework to address this important practical issue is developed here. We describe a pair of velocity transformations that remove components of the upscale temperature flux in the multiscale intraseasonal, planetary, equatorial synoptic-scale dynamics (IPESD) framework derived by Majda and Klein [J. Atmos. Sci. 60: 393-408, (2003)]. Using examples from the models of the Madden-Julian Oscillation of Biello and Majda [Proc. Natl. Acad. Sci. 101: 4736-4741, (2004); J. Atmos. Sci. 62: 1694-1721, (2005); Dyn. Oceans Atmos., in press] we demonstrate that the transformation for the meridional temperature flux convergence is possible with any restrictions on the heating profile, we show under which conditions the transformation for the vertical temperature flux convergence exists and, further, that the meridional transformation leads to a reinterpretation of lower troposphere Ekman dissipation as active heating plus zonal momentum drag. The meridional temperature flux transformation and induced meridional circulation is a new, tropical wave example of the transformed Eulerian mean theory in the case of strong vertical stratification of potential temperature. The asymptotic ordering of the flows means that the removal of the meridional temperature flux convergence has implications for how planetary-scale heating rates are inferred from velocity convergence measurements. (orig.)
MODEL TRANSFORMATION DEVELOPMENT USING MOLA MAPPINGS AND TEMPLATE MOLA
Kalniņa, Elīna
2012-01-01
Darbā pētīta modeļu transformāciju izstrāde 3 specializētos problēmu apgabalos: transformācijas modeļ-bāzētai izstrādei, transformācijas grafisku modelēšanas valodu rīku būvei un transformācijas, kas sintezē transformācijas. Secināts, ka valodā, kas pielāgota konkrētajam apgabalam, transformāciju izstrāde ir vienkāršāka un ātrāka. Visiem trim pētītajiem apgabaliem tika izstrādātas tiem pielāgotas valodas. Divas no izstrādātajām valodām balstās uz attēlojumu principiem. Abos gadījumos tika sec...
Modeling mechanical effects on promotion and retardation of martensitic transformation
Energy Technology Data Exchange (ETDEWEB)
Maalekian, Mehran, E-mail: mehran.maalekian@ubc.ca [Department of Materials Engineering, University of British Columbia, 309-6350 Stores Road, Vancouver, B.C. V61Z4 (Canada); Kozeschnik, Ernst [Christian Doppler Laboratory for ' Early Stages of Precipitation' , Institute of Materials Science and Technology, Vienna University of Technology (Austria)
2011-01-25
Research highlights: {yields} Compressive elastic stresses up to 250 MPa are applied in continuous cooling. {yields} Using the thermodynamic data and maximum value of the mechanical driving force the predicted increase in M{sub s} ({approx}0.1 K/MPa) is in agreement with experiment {yields} Austenite was deformed plastically at different temperatures (800 deg. C-1100 deg. C). {yields} High deformation temperature (i.e. 1100 deg. C) as well as low plastic strain (i.e. {epsilon}{sub ave} {approx} 30%) do not affect martensite transformation noticeably, whereas lower deformation temperature (e.g. 900 deg. C) and large plastic strain (i.e. {epsilon}{sub ave} {approx} 70%) retards martensite transformation. {yields} The theory of mechanical stabilization predicts the depression of M{sub s}. - Abstract: The influence of compressive stress and prior plastic deformation of austenite on the martensite transformation in a eutectoid steel is studied both experimentally and theoretically. It is demonstrated that martensite formation is assisted by stress but it is retarded when transformation occurs from deformed austenite. With the quantitative modeling of the problem based on the theory of displacive shear transformation, the explanation of the two opposite roles of mechanical treatment prior to or simultaneously to martensite transformation is presented.
Institute of Scientific and Technical Information of China (English)
XING Ting-yong; ZHENG Yan-jun; CUI Li-shan
2005-01-01
The recovery stress characteristics of a TiNi shape memory alloy wire under different constraint conditions were studied. The results show that the recovery stress rate (dσ/dT) in the second heating cycle increases significantly with the increasing constraining-spring coefficient in the first heating cycle. As a result, a distinct discontinuity appears on the recovery stress curves of the TiNi alloy wires in the second heating process. Also, the results of differential scanning calorimeter(DSC) measurements show that after the thermomechanical process, the heating curve of the TiNi alloy wire consists of two independent endothermic peaks.
The role of technology and engineering models in transforming healthcare.
Pavel, Misha; Jimison, Holly Brugge; Wactlar, Howard D; Hayes, Tamara L; Barkis, Will; Skapik, Julia; Kaye, Jeffrey
2013-01-01
The healthcare system is in crisis due to challenges including escalating costs, the inconsistent provision of care, an aging population, and high burden of chronic disease related to health behaviors. Mitigating this crisis will require a major transformation of healthcare to be proactive, preventive, patient-centered, and evidence-based with a focus on improving quality-of-life. Information technology, networking, and biomedical engineering are likely to be essential in making this transformation possible with the help of advances, such as sensor technology, mobile computing, machine learning, etc. This paper has three themes: 1) motivation for a transformation of healthcare; 2) description of how information technology and engineering can support this transformation with the help of computational models; and 3) a technical overview of several research areas that illustrate the need for mathematical modeling approaches, ranging from sparse sampling to behavioral phenotyping and early detection. A key tenet of this paper concerns complementing prior work on patient-specific modeling and simulation by modeling neuropsychological, behavioral, and social phenomena. The resulting models, in combination with frequent or continuous measurements, are likely to be key components of health interventions to enhance health and wellbeing and the provision of healthcare.
Lie algebraic similarity transformed Hamiltonians for lattice model systems
Wahlen-Strothman, Jacob M.; Jiménez-Hoyos, Carlos A.; Henderson, Thomas M.; Scuseria, Gustavo E.
2015-01-01
We present a class of Lie algebraic similarity transformations generated by exponentials of two-body on-site Hermitian operators whose Hausdorff series can be summed exactly without truncation. The correlators are defined over the entire lattice and include the Gutzwiller factor ni ↑ni ↓ , and two-site products of density (ni ↑+ni ↓) and spin (ni ↑-ni ↓) operators. The resulting non-Hermitian many-body Hamiltonian can be solved in a biorthogonal mean-field approach with polynomial computational cost. The proposed similarity transformation generates locally weighted orbital transformations of the reference determinant. Although the energy of the model is unbound, projective equations in the spirit of coupled cluster theory lead to well-defined solutions. The theory is tested on the one- and two-dimensional repulsive Hubbard model where it yields accurate results for small and medium sized interaction strengths.
Development and Validation of a Tokamak Skin Effect Transformer model
Romero, J A; Coda, S; Felici, F; Garrido, I
2012-01-01
A control oriented, lumped parameter model for the tokamak transformer including the slow flux penetration in the plasma (skin effect transformer model) is presented. The model does not require detailed or explicit information about plasma profiles or geometry. Instead, this information is lumped in system variables, parameters and inputs. The model has an exact mathematical structure built from energy and flux conservation theorems, predicting the evolution and non linear interaction of the plasma current and internal inductance as functions of the primary coil currents, plasma resistance, non-inductive current drive and the loop voltage at a specific location inside the plasma (equilibrium loop voltage). Loop voltage profile in the plasma is substituted by a three-point discretization, and ordinary differential equations are used to predict the equilibrium loop voltage as function of the boundary and resistive loop voltages. This provides a model for equilibrium loop voltage evolution, which is reminiscent ...
A Bi-Objective Model for Siting Park-and-Ride Facilities with Spatial Equity Constraints
Directory of Open Access Journals (Sweden)
Xiao-Shan Lu
2015-08-01
Full Text Available A bi-objective programming model (BP with spatial equity constraints is proposed to site park-and-ride (P&R facilities in traffic networks. Both the number and locations of P&R facilities are determined. The maximal coverage and minimal resource utilization criteria, which are generally conflicting, are simultaneously considered to reveal the trade-off between the quality and cost of coverage. Furthermore, the concept of passenger flow volume per cost is defined and several properties of the model solutions are analyzed. Finally, this model is applied to site P&R facilities in Anaheim, California. Application results show the trade-offs associated with passenger flow volume, cost and passenger flow volume per cost, and the effects of spatial equity constraints on the spatial deployment of P&R facilities.
How robust are inflation model and dark matter constraints from cosmological data?
DEFF Research Database (Denmark)
Hamann, Jan; Hannestad, Steen; Sloth, Martin Snoager;
2006-01-01
High-precision data from observation of the cosmic microwave background and the large scale structure of the universe provide very tight constraints on the effective parameters that describe cosmological inflation. Indeed, within a constrained class of LambdaCDM models, the simple lambda phi^4...... chaotic inflation model already appears to be ruled out by cosmological data. In this paper, we compute constraints on inflationary parameters within a more general framework that includes other physically motivated parameters such as a nonzero neutrino mass. We find that a strong degeneracy between...... the tensor-to-scalar ratio r and the neutrino mass prevents lambda phi^4 from being excluded by present data. Reversing the argument, if lambda phi^4 is the correct model of inflation, it predicts a sum of neutrino masses at 0.3-0.5 eV, a range compatible with present experimental limits and within the reach...
DEFF Research Database (Denmark)
Machado, Daniel; Herrgard, Markus
2014-01-01
Constraint-based models of metabolism are a widely used framework for predicting flux distributions in genome-scale biochemical networks. The number of published methods for integration of transcriptomic data into constraint-based models has been rapidly increasing. So far the predictive capability...... of these methods has not been critically evaluated and compared. This work presents a survey of recently published methods that use transcript levels to try to improve metabolic flux predictions either by generating flux distributions or by creating context-specific models. A subset of these methods...... of the results to method-specific parameters is also evaluated, as well as their robustness to noise in the data. The results show that none of the methods outperforms the others for all cases. Also, it is observed that for many conditions, the predictions obtained by simple flux balance analysis using growth...
The effect of service level constraint on EPQ model with random defective rate
Directory of Open Access Journals (Sweden)
2006-01-01
Full Text Available We study the effect of service level constraint on the economic production quantity (EPQ model with random defective rate. We first prove that the expected overall cost for imperfect quality EPQ model with backlogging permitted is less than or equal to that of the same model without backlogging. Secondly, the relationship between “imputed backorder cost” and maximal shortage level is derived for decision-making on whether the required service level is achievable. Then an equation is proposed for calculating the intangible backorder cost for the situation when the required service level is not attainable. By including this intangible backorder cost in the mathematical analysis, one can derive a new optimal lot-size policy that minimizes expected total costs as well as satisfies the service level constraint. Numerical example is provided to demonstrate its practical usage.
Experimental studies on power transformer model winding provided with MOVs
Directory of Open Access Journals (Sweden)
G.H. Kusumadevi
2017-05-01
Full Text Available Surge voltage distribution across a HV transformer winding due to appearance of very fast rise time (rise time of order 1 μs transient voltages is highly non-uniform along the length of the winding for initial time instant of occurrence of surge. In order to achieve nearly uniform initial time instant voltage distribution along the length of the HV winding, investigations have been carried out on transformer model winding. By connecting similar type of metal oxide varistors across sections of HV transformer model winding, it is possible to improve initial time instant surge voltage distribution across length of the HV transformer winding. Transformer windings with α values 5.3, 9.5 and 19 have been analyzed. The experimental studies have been carried out using high speed oscilloscope of good accuracy. The initial time instant voltage distribution across sections of winding with MOV remains nearly uniform along length of the winding. Also results of fault diagnostics carried out with and without connection of MOVs across sections of winding are reported.
Relating Weight Constraint and Aggregate Programs: Semantics and Representation
Liu, Guohua
2011-01-01
Weight constraint and aggregate programs are among the most widely used logic programs with constraints. In this paper, we relate the semantics of these two classes of programs, namely the stable model semantics for weight constraint programs and the answer set semantics based on conditional satisfaction for aggregate programs. Both classes of programs are instances of logic programs with constraints, and in particular, the answer set semantics for aggregate programs can be applied to weight constraint programs. We show that the two semantics are closely related. First, we show that for a broad class of weight constraint programs, called strongly satisfiable programs, the two semantics coincide. When they disagree, a stable model admitted by the stable model semantics may be circularly justified. We show that the gap between the two semantics can be closed by transforming a weight constraint program to a strongly satisfiable one, so that no circular models may be generated under the current implementation of ...
LAPLACE TRANSFORM OF THE SURVIVAL PROBABILITY UNDER SPARRE ANDERSEN MODEL
Institute of Scientific and Technical Information of China (English)
Sun Chuanguang
2007-01-01
In this paper a class of risk processes in which claims occur as a renewal process is studied. A clear expression for Laplace transform of the survival probability is well given when the claim amount distribution is Erlang distribution or mixed Erlang distribution. The expressions for moments of the time to ruin with the model above are given.
Transforming a School of Education via the Accelerated Schools Model.
Mims, J. Sabrina; Slovacek, Simeon; Wong, Gay Yuen
This paper describes how the Accelerated Schools Model has served as a catalyst for transforming the Charter School of Education at California State University, Los Angeles. The Accelerated Schools Project has been one of the largest and most comprehensive school restructuring movements of the last decade. The focus of Accelerated Schools is…
Model Transformation for a System of Systems Dependability Safety Case
Murphy, Judy; Driskell, Steve
2011-01-01
The presentation reviews the dependability and safety effort of NASA's Independent Verification and Validation Facility. Topics include: safety engineering process, applications to non-space environment, Phase I overview, process creation, sample SRM artifact, Phase I end result, Phase II model transformation, fault management, and applying Phase II to individual projects.
A Concept Transformation Learning Model for Architectural Design Learning Process
Wu, Yun-Wu; Weng, Kuo-Hua; Young, Li-Ming
2016-01-01
Generally, in the foundation course of architectural design, much emphasis is placed on teaching of the basic design skills without focusing on teaching students to apply the basic design concepts in their architectural designs or promoting students' own creativity. Therefore, this study aims to propose a concept transformation learning model to…
A Concept Transformation Learning Model for Architectural Design Learning Process
Wu, Yun-Wu; Weng, Kuo-Hua; Young, Li-Ming
2016-01-01
Generally, in the foundation course of architectural design, much emphasis is placed on teaching of the basic design skills without focusing on teaching students to apply the basic design concepts in their architectural designs or promoting students' own creativity. Therefore, this study aims to propose a concept transformation learning model to…
Bernardini, Davide; Pence, Thomas J
2016-04-28
Models for shape memory material behaviour can be posed in the framework of a structured continuum theory. We study such a framework in which a scalar phase fraction field and a tensor field of martensite reorientation describe the material microstructure, in the context of finite strains. Gradients of the microstructural descriptors naturally enter the formulation and offer the possibility to describe and resolve phase transformation localizations. The constitutive theory is thoroughly described by a single free energy function in conjunction with a path-dependent dissipation function. Balance laws in the form of differential equations are obtained and contain both bulk and surface terms, the latter in terms of microstreses. A natural constraint on the tensor field for martensite reorientation gives rise to reactive fields in these balance laws. Conditions ensuring objectivity as well as the relation of this framework to that provided by currently used models for shape memory alloy behaviour are discussed.
Cubic constraints for the resolvents of the ABJM matrix model and its cousins
Itoyama, Hiroshi; Suyama, Takao; Yoshioka, Reiji
2016-01-01
A set of Schwinger-Dyson equations forming constraints for at most three resolvent functions are considered for a class of Chern-Simons matter matrix models with two nodes labelled by a non-vanishing number $n$. The two cases $n=2$ and $n= -2$ label respectively the ABJM matrix model, which is the hyperbolic lift of the affine $A_1^{(1)}$ quiver matrix model, and the lens space matrix model. In the planar limit, we derive two cubic loop equations for the two planar resolvents. One of these reduces to the quadratic one when $n = \\pm 2$.
A Microscale Model for Ausferritic Transformation of Austempered Ductile Irons
Boccardo, Adrián D.; Dardati, Patricia M.; Celentano, Diego J.; Godoy, Luis A.
2017-01-01
This paper presents a new metallurgical model for the ausferritic transformation of ductile cast iron. The model allows predicting the evolution of phases in terms of the chemical composition, austenitization and austempering temperatures, graphite nodule count, and distribution of graphite nodule size. The ferrite evolution is predicted according to the displacive growth mechanism. A representative volume element is employed at the microscale to consider the phase distributions, the inhomogeneous austenite carbon content, and the nucleation of ferrite subunits at the graphite nodule surface and at the tips of existing ferrite subunits. The performance of the model is evaluated by comparison with experimental results. The results indicate that the increment of the ausferritic transformation rate, which is caused by increments of austempering temperature and graphite nodule count, is adequately represented by this model.
Transformation of equations in analysis of proportionality through referent models
Romay, E O
2006-01-01
In proportionality of objects, samples or populations, usually we work with Z score of proportionality calculated through referent models, instead directly with the variables of the objects in itself. In these studies we have the necessity to transform, the equations that use the variables of the object, in equations that directly use like variables Z score. In the present work a method is developed to transform the parametric equations, in equations in variables Z using like example the studies of human proportionality from the Phantom stratagem of Ross and Wilson.
Directory of Open Access Journals (Sweden)
Soliman Sylvain
2012-05-01
Full Text Available Abstract Background We present a way to compute the minimal semi-positive invariants of a Petri net representing a biological reaction system, as resolution of a Constraint Satisfaction Problem. The use of Petri nets to manipulate Systems Biology models and make available a variety of tools is quite old, and recently analyses based on invariant computation for biological models have become more and more frequent, for instance in the context of module decomposition. Results In our case, this analysis brings both qualitative and quantitative information on the models, in the form of conservation laws, consistency checking, etc. thanks to finite domain constraint programming. It is noticeable that some of the most recent optimizations of standard invariant computation techniques in Petri nets correspond to well-known techniques in constraint solving, like symmetry-breaking. Moreover, we show that the simple and natural encoding proposed is not only efficient but also flexible enough to encompass sub/sur-invariants, siphons/traps, etc., i.e., other Petri net structural properties that lead to supplementary insight on the dynamics of the biochemical system under study. Conclusions A simple implementation based on GNU-Prolog's finite domain solver, and including symmetry detection and breaking, was incorporated into the BIOCHAM modelling environment and in the independent tool Nicotine. Some illustrative examples and benchmarks are provided.
Bi-Level Multi-criteria Multiple Constraint Level Optimization MODELS and Its Application
Directory of Open Access Journals (Sweden)
Lei Zhao
2013-05-01
Full Text Available Because oil field development system is a large hierarchical and uncertain system, this paper uses the theory of bi-level programming and multi-criteria multiple constraint level ( to formulate a new oilfield measure structural optimization model which is bi-level multiple objectives and multiple constraint level nonlinear programming, and present a new method to solve the bi-level programming whose lower is multiple objectives nonlinear programming, whose upper is linear programming. The result of this model not only may feed back to the comprehensive information of measures output distribution optimization to decision-makers as a whole, but also can provide decision makers oil field exploitation contingency planning to deal with changed resource constraint level. The case study shows that the result fitting calculation by the model is coincide with the historical data of oil field, the model is correct and effective. Moreover this research may provide a reliable new method for oil field development optimal decision-making.
A Discrete Constraint for Entropy Conservation and Sound Waves in Cloud-Resolving Modeling
Zeng, Xi-Ping; Tao, Wei-Kuo; Simpson, Joanne
2003-01-01
Ideal cloud-resolving models contain little-accumulative errors. When their domain is so large that synoptic large-scale circulations are accommodated, they can be used for the simulation of the interaction between convective clouds and the large-scale circulations. This paper sets up a framework for the models, using moist entropy as a prognostic variable and employing conservative numerical schemes. The models possess no accumulative errors of thermodynamic variables when they comply with a discrete constraint on entropy conservation and sound waves. Alternatively speaking, the discrete constraint is related to the correct representation of the large-scale convergence and advection of moist entropy. Since air density is involved in entropy conservation and sound waves, the challenge is how to compute sound waves efficiently under the constraint. To address the challenge, a compensation method is introduced on the basis of a reference isothermal atmosphere whose governing equations are solved analytically. Stability analysis and numerical experiments show that the method allows the models to integrate efficiently with a large time step.
Thiel, Rainer; Viceconti, Marco; Stroetmann, Karl
2011-01-01
Biocomputational modelling as developed by the European Virtual Physiological Human (VPH) Initiative is the area of ICT most likely to revolutionise in the longer term the practice of medicine. Using the example of osteoporosis management, a socio-economic assessment framework is presented that captures how the transformation of clinical guidelines through VPH models can be evaluated. Applied to the Osteoporotic Virtual Physiological Human Project, a consequent benefit-cost analysis delivers promising results, both methodologically and substantially.
Generating WS-SecurityPolicy documents via security model transformation
DEFF Research Database (Denmark)
Jensen, Meiko
2009-01-01
When SOA-based business processes are to be enhanced with security properties, the model-driven business process development approach enables an easier and more reliable security definition compared to manually crafting the security realizations afterwards. In this paper, we outline an appropriate...... security model definition and transformation approach, targeting the WS-SecurityPolicy and WS-BPEL specifications, in order to enable a Web-Service-based secure business process development....
Ontological Modeling of Transformation in Heart Defect Diagrams
Viswanath, Venkatesh; Tong, Tuanjie; Dinakarpandian, Deendayal; Lee, Yugyung
2006-01-01
The accurate portrayal of a large volume data of variable heart defects is crucial to providing good patient care in pediatric cardiology. Our research aims to span the universe of congenital heart defects by generating illustrative diagrams that enhance data interpretation. To accommodate the range and severity of defects to be represented, we base our diagrams on transformation models applied to a normal heart rather than a static set of defects. These models are based on a domain-specific ...
Weber, Arthur L.
2002-01-01
The thermodynamics of organic chemistry under mild aqueous conditions was examined in order to begin to understand its influence on the structure and operation of metabolism and its antecedents. Free energies (deltaG) were estimated for four types of reactions of biochemical importance carbon-carbon bond cleavage and synthesis, hydrogen transfer between carbon groups, dehydration of alcohol groups, and aldo-keto isomerization. The energies were calculated for mainly aliphatic groups composed of carbon, hydrogen, and oxygen. The energy values showed (1) that generally when carbon-carbon bond cleavage involves groups from different functional group classes (i.e., carboxylic acids, carbonyl groups, alcohols, and hydrocarbons), the transfer of the shared electron-pair to the more reduced carbon group is energetically favored over transfer to the more oxidized carbon group, and (2) that the energy of carbon-carbon bond transformation is primarily determined by the functional group class of the group that changes oxidation state in the reaction (i.e., the functional group class of the group that donates the shared electron-pair during cleavage, or that accepts the incipient shared electron-pair during synthesis). In contrast, the energy of hydrogen transfer between carbon groups is determined by the functional group class of both the hydrogen-donor group and the hydrogen-acceptor group. From these and other observations we concluded that the chemistry involved in the origin of metabolism (and to a lesser degree modern metabolism) was strongly constrained by (1) the limited redox-based transformation energy of organic substrates that is readily dissipated in a few energetically favorable irreversible reactions; (2) the energy dominance of a few transformation half-reactions that determines whether carbon-carbon bond transformation (cleavage or synthesis) is energetically favorable (deltaG +3.5 kcal/mol); and (3) the dependence of carbon group transformation energy on the
Dislocation Model and Morphology Simulation of bcc fcc Martensitic Transformation
Institute of Scientific and Technical Information of China (English)
无
2000-01-01
By using molecular dynamics computer simulation at atomic level, the effects of single dislocation and dipole dislocations on nucleation and growth of martensitic transformation have been studied. It was found that only the location of tension or compression stress fields of the dislocations are favorable for martensite nucleation in NiAl alloy and the dislocations can move to accommodate partly the transformation strain during the nucleation and growth of martensite. Combined with the molecular dynamics simulation, a two dimensional simulation for martensite morphology based on a dislocation model bas been performed. Many factors related to martensitic transformation were considered, such as supercooling, interface energy, shear strain, normal strain and hydrostatic pressure. Different morphologies of martensites, similar to lath, lenticular, thin plate, couple-plate and lenticular couple-plate martensites observed in Fe-C and Fe-Ni-C alloys, were obtained.
Similarity transformation approach to identifiability analysis of nonlinear compartmental models.
Vajda, S; Godfrey, K R; Rabitz, H
1989-04-01
Through use of the local state isomorphism theorem instead of the algebraic equivalence theorem of linear systems theory, the similarity transformation approach is extended to nonlinear models, resulting in finitely verifiable sufficient and necessary conditions for global and local identifiability. The approach requires testing of certain controllability and observability conditions, but in many practical examples these conditions prove very easy to verify. In principle the method also involves nonlinear state variable transformations, but in all of the examples presented in the paper the transformations turn out to be linear. The method is applied to an unidentifiable nonlinear model and a locally identifiable nonlinear model, and these are the first nonlinear models other than bilinear models where the reason for lack of global identifiability is nontrivial. The method is also applied to two models with Michaelis-Menten elimination kinetics, both of considerable importance in pharmacokinetics, and for both of which the complicated nature of the algebraic equations arising from the Taylor series approach has hitherto defeated attempts to establish identifiability results for specific input functions.
Model construction from orthographic views as Pseudo Boolean constraint satisfaction problem
Energy Technology Data Exchange (ETDEWEB)
Itoh, Kiyoshi; Suzuki, Shigemich [Sophia Univ., Tokyo (Japan)
1996-12-31
A surface model representation of a solid can be constructed in straightforward fashion from a set of three orthographic views. The surface model may include ghost vertexes, ghost edges and ghost faces. The authors` project, called Sophia-Alsovig, treats the problem for obtaining valid combination of surfaces and edges as Pseudo Boolean constraint satisfaction problem (CSP). It can remove such ghosts. As CSP, Sophia-Alsovig adopts a set of units consisting of edges and surfaces, a set of Boolean labels, and a set of constraints with the formulation of a collection of topological/geometrical rules for edges and surfaces by Pseudo Boolean equations. Sophia-Alsovig obtains solutions by Pseudo Boolean Nonlinear Programming.
Jarosz, Gaja
2010-06-01
This study examines the interacting roles of implicational markedness and frequency from the joint perspectives of formal linguistic theory, phonological acquisition and computational modeling. The hypothesis that child grammars are rankings of universal constraints, as in Optimality Theory (Prince & Smolensky, 1993/2004), that learning involves a gradual transition from an unmarked initial state to the target grammar, and that order of acquisition is guided by frequency, along the lines of Levelt, Schiller & Levelt (2000), is investigated. The study reviews empirical findings on syllable structure acquisition in Dutch, German, French and English, and presents novel findings on Polish. These comparisons reveal that, to the extent allowed by implicational markedness universals, frequency covaries with acquisition order across languages. From the computational perspective, the paper shows that interacting roles of markedness and frequency in a class of constraint-based phonological learning models embody this hypothesis, and their predictions are illustrated via computational simulation.
A model problem for conformal parameterizations of the Einstein constraint equations
Maxwell, David
2009-01-01
We investigate the possibility that the conformal and conformal thin sandwich (CTS) methods can be used to parameterize the set of solutions of the vacuum Einstein constraint equations. To this end we develop a model problem obtained by taking the quotient of certain symmetric data on conformally flat tori. Specializing the model problem to a three-parameter family of conformal data we observe a number of new phenomena for the conformal and CTS methods. Within this family, we obtain a general existence theorem so long as the mean curvature does not change sign. When the mean curvature changes sign, we find that for certain data solutions exist if and only if the transverse-traceless tensor is sufficiently small. When such solutions exist, there are generically more than one. Moreover, the theory for mean curvatures changing sign is shown to be extremely sensitive with respect to the value of a coupling constant in the Einstein constraint equations.
Fuks, Benjamin; Herrmann, Björn; Klasen, Michael
2009-03-01
We present an extensive analysis of gauge-mediated supersymmetry breaking models with minimal and non-minimal flavour violation. We first demonstrate that low-energy, precision electroweak, and cosmological constraints exclude large "collider-friendly" regions of the minimal parameter space. We then discuss various possibilities how flavour violation, although naturally suppressed, may still occur in gauge-mediation models. The introduction of non-minimal flavour violation at the electroweak scale is shown to relax the stringent experimental constraints, so that benchmark points, that are also cosmologically viable, can be defined and their phenomenology, i.e. squark and gaugino production cross sections with flavour violation, at the LHC can be studied.
Fuks, B; Klasen, M
2008-01-01
We present an extensive analysis of gauge-mediated supersymmetry breaking models with minimal and non-minimal flavour violation. We first demonstrate that low-energy, precision electroweak, and cosmological constraints exclude large "collider-friendly" regions of the minimal parameter space. We then discuss various possibilities how flavour violation, although naturally suppressed, may still occur in gauge-mediation models. The introduction of non-minimal flavour violation at the electroweak scale is shown to relax the stringent experimental constraints, so that benchmark points, that are also cosmologically viable, can be defined and their phenomenology, i.e. squark and gaugino production cross sections with flavour violation, at the LHC can be studied.
Energy Technology Data Exchange (ETDEWEB)
Fuks, Benjamin [Physikalisches Institut, Albert-Ludwigs-Universitaet Freiburg, Hermann-Herder-Strasse 3, D-79106 Freiburg im Breisgau (Germany); Herrmann, Bjoern [Laboratoire de Physique Subatomique et de Cosmologie, Universite Joseph Fourier/CNRS-IN2P3/INPG, 53 Avenue des Martyrs, F-38026 Grenoble (France); Klasen, Michael [Laboratoire de Physique Subatomique et de Cosmologie, Universite Joseph Fourier/CNRS-IN2P3/INPG, 53 Avenue des Martyrs, F-38026 Grenoble (France)], E-mail: klasen@lpsc.in2p3.fr
2009-03-21
We present an extensive analysis of gauge-mediated supersymmetry breaking models with minimal and non-minimal flavour violation. We first demonstrate that low-energy, precision electroweak, and cosmological constraints exclude large 'collider-friendly' regions of the minimal parameter space. We then discuss various possibilities how flavour violation, although naturally suppressed, may still occur in gauge-mediation models. The introduction of non-minimal flavour violation at the electroweak scale is shown to relax the stringent experimental constraints, so that benchmark points, that are also cosmologically viable, can be defined and their phenomenology, i.e. squark and gaugino production cross sections with flavour violation, at the LHC can be studied.
Institute of Scientific and Technical Information of China (English)
LI Jie-Chao; XU Li-Xin; L(U) Jian-Bo; CHANG Sao-Rong; LIU Hong-Ya
2008-01-01
We study the constraint on deceleration parameter q from the recent SNeIa Gold dataset and observational Hubble data by using a model-independent deceleration parameter q(z)=1/2-a/(1+z)b under the five-dimensional bounce cosmological model.For the cases of SNeIa Gold dataset,Hubble data,and their combination,the present results cosmological.For the cases of SNeIa Cold dataset,and their combintion,the present results show that the constraints on transition redshift zT are 0.35+0.14-0.07,0.68+1.47-0.58,and 0.55+0.18-0.09 with lo errors,respectively.
Current and future constraints on Bekenstein-type models for varying couplings
Leite, A C O
2016-01-01
Astrophysical tests of the stability of dimensionless fundamental couplings, such as the fine-structure constant $\\alpha$ and the proton-to-electron mass ratio $\\mu$, are an optimal probe of new physics. There is a growing interest in these tests, following indications of possible spacetime variations at the few parts per million level. Here we make use of the latest astrophysical measurements, combined with background cosmological observations, to obtain improved constraints on Bekenstein-type models for the evolution of both couplings. These are arguably the simplest models allowing for $\\alpha$ and $\\mu$ variations, and are characterized by a single free dimensionless parameter, $\\zeta$, describing the coupling of the underlying dynamical degree of freedom to the electromagnetic sector. In the former case we find that this parameter is constrained to be $|\\zeta_\\alpha|<4.8\\times10^{-6}$ (improving previous constraints by a factor of 6), while in the latter (which we quantitatively compare to astrophysic...
Statistical Inference in Hidden Markov Models Using k-Segment Constraints.
Titsias, Michalis K; Holmes, Christopher C; Yau, Christopher
2016-01-02
Hidden Markov models (HMMs) are one of the most widely used statistical methods for analyzing sequence data. However, the reporting of output from HMMs has largely been restricted to the presentation of the most-probable (MAP) hidden state sequence, found via the Viterbi algorithm, or the sequence of most probable marginals using the forward-backward algorithm. In this article, we expand the amount of information we could obtain from the posterior distribution of an HMM by introducing linear-time dynamic programming recursions that, conditional on a user-specified constraint in the number of segments, allow us to (i) find MAP sequences, (ii) compute posterior probabilities, and (iii) simulate sample paths. We collectively call these recursions k-segment algorithms and illustrate their utility using simulated and real examples. We also highlight the prospective and retrospective use of k-segment constraints for fitting HMMs or exploring existing model fits. Supplementary materials for this article are available online.
Constraints on radion in a warped extra dimension model from Higgs boson searches at the LHC
Cho, Gi-Chol; Ohno, Yoshiko
2013-01-01
We study constraints on the radion mass and couplings in the Randall-Sundrum model from the recent LHC data on the Standard Model (SM) Higgs boson searches. When the radion is heavy enough so that it can decay into a pair of on-shell Z-bosons, we find that the ZZ channel gives a stringent constraint. For example, if the radion mass m_\\phi is 200 GeV, the scale \\Lambda_\\phi which characterizes the interactions of the radion with the SM fields must be larger than 5 TeV. Even for m_\\phi=1 TeV, we find that the lower bound on \\Lambda_\\phi is 2 TeV.
Housh, M.; Ng, T.; Cai, X.
2012-12-01
The environmental impact is one of the major concerns of biofuel development. While many other studies have examined the impact of biofuel expansion on stream flow and water quality, this study examines the problem from the other side - will and how a biofuel production target be affected by given environmental constraints. For this purpose, an integrated model comprises of different sub-systems of biofuel refineries, transportation, agriculture, water resources and crops/ethanol market has been developed. The sub-systems are integrated into one large-scale model to guide the optimal development plan considering the interdependency between the subsystems. The optimal development plan includes biofuel refineries location and capacity, refinery operation, land allocation between biofuel and food crops, and the corresponding stream flow and nitrate load in the watershed. The watershed is modeled as a network flow, in which the nodes represent sub-watersheds and the arcs are defined as the linkage between the sub-watersheds. The runoff contribution of each sub-watershed is determined based on the land cover and the water uses in that sub-watershed. Thus, decisions of other sub-systems such as the land allocation in the land use sub-system and the water use in the refinery sub-system define the sources and the sinks of the network. Environmental policies will be addressed in the integrated model by imposing stream flow and nitrate load constraints. These constraints can be specified by location and time in the watershed to reflect the spatial and temporal variation of the regulations. Preliminary results show that imposing monthly water flow constraints and yearly nitrate load constraints will change the biofuel development plan dramatically. Sensitivity analysis is performed to examine how the environmental constraints and their spatial and the temporal distribution influence the overall biofuel development plan and the performance of each of the sub
Positivity and unitarity constraints on dipole gluon distributions
Peschanski, Robi
2016-01-01
In the high-energy domain, gluon transverse-momentum dependent distributions in nuclei obey constraints coming from positivity and unitarity of the colorless QCD dipole distributions through Fourier-Bessel transformations. Using mathematical properties of Fourier-positive functions, we investigate the nature of these constraints which apply to dipole model building and formulation
Stochastic Constraint Programming
Walsh, Toby
2009-01-01
To model combinatorial decision problems involving uncertainty and probability, we introduce stochastic constraint programming. Stochastic constraint programs contain both decision variables (which we can set) and stochastic variables (which follow a probability distribution). They combine together the best features of traditional constraint satisfaction, stochastic integer programming, and stochastic satisfiability. We give a semantics for stochastic constraint programs, and propose a number...
Discrete and Continuum Virasoro Constraints in Two-Cut Hermitian Matrix Models
Ogura, W
1993-01-01
Continuum Virasoro constraints in the two-cut hermitian matrix models are derived from the discrete Ward identities by means of the mapping from the $GL(\\infty )$ Toda hierarchy to the nonlinear Schr\\"odinger (NLS) hierarchy. The invariance of the string equation under the NLS flows is worked out. Also the quantization of the integration constant $\\alpha$ reported by Hollowood et al. is explained by the analyticity of the continuum limit.
Multimodal electromechanical model of piezoelectric transformers by Hamilton's principle.
Nadal, Clement; Pigache, Francois
2009-11-01
This work deals with a general energetic approach to establish an accurate electromechanical model of a piezoelectric transformer (PT). Hamilton's principle is used to obtain the equations of motion for free vibrations. The modal characteristics (mass, stiffness, primary and secondary electromechanical conversion factors) are also deduced. Then, to illustrate this general electromechanical method, the variational principle is applied to both homogeneous and nonhomogeneous Rosen-type PT models. A comparison of modal parameters, mechanical displacements, and electrical potentials are presented for both models. Finally, the validity of the electrodynamical model of nonhomogeneous Rosen-type PT is confirmed by a numerical comparison based on a finite elements method and an experimental identification.
Cosmic Constraints to wCDM Model from Strong Gravitational Lensing
An, Jie; Xu, Lixin
2016-01-01
In this paper, we study the cosmic constraint to $w$CDM model via $118$ strong gravitational lensing systems which are complied from SLACS, BELLS, LSD and SL2S surveys, where the ratio between two angular diameter distances $D^{obs} = D_A(z_l,z_s)/D_A(0,z_s)$ is taken as a cosmic observable. To obtain this ratio, we adopt two strong lensing models: one is the singular isothermal sphere model (SIS), the other one is the power-law density profile (PLP) model. Via the Markov Chain Mote Carlo method, the posterior distribution of the cosmological model parameters space is obtained. The results show that the cosmological model parameters are not sensitive to the parameterized forms of the power-law index $\\gamma$. Furthermore, the PLP model gives a relative tighter constraint to the cosmological parameters than that of the SIS model. The predicted value of $\\Omega_m=0.31^{+0.44}_{-0.24}$ by SIS model is compatible with that obtained by {\\it Planck}2015: $\\Omega_{m}=0.313\\pm0.013$. However, the value of $\\Omega_m=0...
High frequency modeling of power transformers. Stresses and diagnostics
Energy Technology Data Exchange (ETDEWEB)
Bjerkan, Eilert
2005-05-15
In this thesis a reliable, versatile and rigorous method for high frequency power transformer modeling is searched and established. The purpose is to apply this model to sensitivity analysis of FRA (Frequency Response Analysis) which is a quite new diagnostic method for assessing the mechanical integrity of power transformer windings on-site. The method should be versatile in terms of being able to estimate internal and external over voltages and resonances. Another important aspect is that the method chosen is suitable for real transformer geometries. In order to verify the suitability of the model for real transformers, a specific test-object is used. This is a 20MVA transformer, and details are given in chapter 1.4. The high frequency power transformer model is established from geometrical and constructional information from the manufacturer, together with available material characteristics. All circuit parameters in the lumped circuit representation are calculated based on these data. No empirical modifications need to be performed. Comparison shows capability of reasonable accuracy in the range from 10 khz to 1 MHz utilizing a disc-to-disc representation. A compromise between accuracy of model due to discretization and complexity of the model in a turn-to-turn representation is inevitable. The importance of the iron core is emphasized through a comparison of representations with/without the core included. Frequency-dependent phenomena are accurately represented using an isotropic equivalent for windings and core, even with a coarse mesh for the FEM-model. This is achieved through a frequency-dependent complex permeability representation of the materials. This permeability is deduced from an analytical solution of the frequency-dependent magnetic field inside the conductors and the core. The importance of dielectric losses in a transformer model is also assessed. Since published data on the high frequency properties of press board are limited, some initial
B-splines as a Tool to Solve Constraints in Non-Hydrostatic Forecast Model
Subias, Alvaro
2016-01-01
Finite elements has been proven to be an useful tool to discretize the vertical coordinate in the hydrostatic forecast models allowing to define model variables in full levels so that no staggering is needed. In the non-hydrostatic case a constraint in the vertical operators appears (called C1) that does not allow to reduce the set of semi-implicit linear equations to a single equation in one variable as in the analytic case. Recently vertical finite elements based in B-splines have been used with an iterative method to relax the C1 constraint. In this paper we want to develop properly some representations of vertical operators in terms of B-splines in order to keep the C1-constraint. An invertibility relation between integral and derivative operators between vertical velocity and vertical divergence is also presented. The final scope of this paper is to provide a theoretical framework of development of finite element vertical operators to be implemented in the nh-Harmonie model
Model-independent indirect detection constraints on hidden sector dark matter
Elor, Gilly; Rodd, Nicholas L.; Slatyer, Tracy R.; Xue, Wei
2016-06-01
If dark matter inhabits an expanded ``hidden sector'', annihilations may proceed through sequential decays or multi-body final states. We map out the potential signals and current constraints on such a framework in indirect searches, using a model-independent setup based on multi-step hierarchical cascade decays. While remaining agnostic to the details of the hidden sector model, our framework captures the generic broadening of the spectrum of secondary particles (photons, neutrinos, e+e- and bar p p) relative to the case of direct annihilation to Standard Model particles. We explore how indirect constraints on dark matter annihilation limit the parameter space for such cascade/multi-particle decays. We investigate limits from the cosmic microwave background by Planck, the Fermi measurement of photons from the dwarf galaxies, and positron data from AMS-02. The presence of a hidden sector can change the constraints on the dark matter by up to an order of magnitude in either direction (although the effect can be much smaller). We find that generally the bound from the Fermi dwarfs is most constraining for annihilations to photon-rich final states, while AMS-02 is most constraining for electron and muon final states; however in certain instances the CMB bounds overtake both, due to their approximate independence on the details of the hidden sector cascade. We provide the full set of cascade spectra considered here as publicly available code with examples at http://web.mit.edu/lns/research/CascadeSpectra.html.
How robust are inflation model and dark matter constraints from cosmological data?
Hamann, J; Sloth, M S; Wong, Y Y Y; Hamann, Jan; Hannestad, Steen; Sloth, Martin S.; Wong, Yvonne Y.Y.
2006-01-01
High-precision data from observation of the cosmic microwave background and the large scale structure of the universe provide very tight constraints on the effective parameters that describe cosmological inflation. Indeed, within a constrained class of LambdaCDM models, the simple lambda phi^4 chaotic inflation model already appears to be ruled out by cosmological data. In this paper, we compute constraints on inflationary parameters within a more general framework that includes other physically motivated parameters such as a nonzero neutrino mass. We find that a strong degeneracy between the tensor-to-scalar ratio r and the neutrino mass prevents lambda phi^4 from being excluded by present data. Reversing the argument, if lambda phi^4 is the correct model of inflation, it predicts a sum of neutrino masses at 0.3-0.5 eV, a range compatible with present experimental limits and within the reach of the next generation of neutrino mass measurements. We also discuss the associated constraints on the dark matter de...
Transforming High School Physics with Modeling and Computation
Aiken, John M
2013-01-01
The Engage to Excel (PCAST) report, the National Research Council's Framework for K-12 Science Education, and the Next Generation Science Standards all call for transforming the physics classroom into an environment that teaches students real scientific practices. This work describes the early stages of one such attempt to transform a high school physics classroom. Specifically, a series of model-building and computational modeling exercises were piloted in a ninth grade Physics First classroom. Student use of computation was assessed using a proctored programming assignment, where the students produced and discussed a computational model of a baseball in motion via a high-level programming environment (VPython). Student views on computation and its link to mechanics was assessed with a written essay and a series of think-aloud interviews. This pilot study shows computation's ability for connecting scientific practice to the high school science classroom.
Tensor product model transformation based decoupled terminal sliding mode control
Zhao, Guoliang; Li, Hongxing; Song, Zhankui
2016-06-01
The main objective of this paper is to propose a tensor product model transformation based decoupled terminal sliding mode controller design methodology. The methodology is divided into two steps. In the first step, tensor product model transformation is applied to the single-input-multi-output system and a parameter-varying weighted linear time-invariant system is obtained. Then, decoupled terminal sliding mode controller is designed based on the linear time-invariant systems. The main novelty of this paper is that the nonsingular terminal sliding mode control design is based on a numerical model rather than an analytical one. Finally, simulations are tested on cart-pole system and translational oscillations with a rotational actuator system.
Observational Constraints on the Unified Dark-Energy-Dark-Matter Model
Institute of Scientific and Technical Information of China (English)
WU Pu-Xun; YU Hong-Wei
2007-01-01
We investigate the constraints on a generalized Chaplygin gas (GCC) model using the gold sample type-Ia supernovae (She Ia) data, the new Supernova Legacy Survey (SNLS) She Ia data and the size of baryonic acoustic oscillation peak found in Sloan Digital Sky Survey (SDSS). In a spatially flat universe case we obtain, at a 95.4% confidence level, As = 0.76-0.07+0.07 and α = 0.028-0.238+0.322. Our results are consistent with the ACDM model (α = 0), but rule out the standard Chaplygin gas model (α = 1).
Hybrid neural modelling of an anaerobic digester with respect to biological constraints.
Karama, A; Bernard, O; Gouzé, J L; Benhammou, A; Dochain, D
2001-01-01
A hybrid model for an anaerobic digestion process is proposed. The fermentation is assumed to be performed in two steps, acidogenesis and methanogenesis, by two bacterial populations. The model is based on mass balance equations, and the bacterial growth rates are represented by neural networks. In order to guarantee the biological meaning of the hybrid model (positivity of the concentrations, boundedness, saturation or inhibition of the growth rates) outside the training data set, a method that imposes constraints in the neural network is proposed. The method is applied to experimental data from a fixed bed reactor.
Development of Transformations from Business Process Models to Implementations by Reuse
Dirgahayu, Teduh; Quartel, Dick; Sinderen, van Marten
2007-01-01
This paper presents an approach for developing transformations from business process models to implementations that facilitates reuse. A transformation is developed as a composition of three smaller tasks: pattern recognition, pattern realization and activity transformation. The approach allows one
Development of transformations from business process models to implementations by reuse
Dirgahayu, Teduh; Quartel, Dick; Sinderen, van Marten; Ferreira Pires, L.; Hammoudi, S.
2007-01-01
This paper presents an approach for developing transformations from business process models to implementations that facilitates reuse. A transformation is developed as a composition of three smaller tasks: pattern recognition, pattern realization and activity transformation. The approach allows one
Stable Eutectoid Transformation in Nodular Cast Iron: Modeling and Validation
Carazo, Fernando D.; Dardati, Patricia M.; Celentano, Diego J.; Godoy, Luis A.
2016-10-01
This paper presents a new microstructural model of the stable eutectoid transformation in a spheroidal cast iron. The model takes into account the nucleation and growth of ferrite grains and the growth of graphite spheroids. Different laws are assumed for the growth of both phases during and below the intercritical stable eutectoid. At a microstructural level, the initial conditions for the phase transformations are obtained from the microstructural simulation of solidification of the material, which considers the divorced eutectic and the subsequent growth of graphite spheroids up to the initiation of the stable eutectoid transformation. The temperature field is obtained by solving the energy equation by means of finite elements. The microstructural (phase change) and macrostructural (energy balance) models are coupled by a sequential multiscale procedure. Experimental validation of the model is achieved by comparison with measured values of fractions and radius of 2D view of ferrite grains. Agreement with such experiments indicates that the present model is capable of predicting ferrite phase fraction and grain size with reasonable accuracy.
Stable Eutectoid Transformation in Nodular Cast Iron: Modeling and Validation
Carazo, Fernando D.; Dardati, Patricia M.; Celentano, Diego J.; Godoy, Luis A.
2017-01-01
This paper presents a new microstructural model of the stable eutectoid transformation in a spheroidal cast iron. The model takes into account the nucleation and growth of ferrite grains and the growth of graphite spheroids. Different laws are assumed for the growth of both phases during and below the intercritical stable eutectoid. At a microstructural level, the initial conditions for the phase transformations are obtained from the microstructural simulation of solidification of the material, which considers the divorced eutectic and the subsequent growth of graphite spheroids up to the initiation of the stable eutectoid transformation. The temperature field is obtained by solving the energy equation by means of finite elements. The microstructural (phase change) and macrostructural (energy balance) models are coupled by a sequential multiscale procedure. Experimental validation of the model is achieved by comparison with measured values of fractions and radius of 2D view of ferrite grains. Agreement with such experiments indicates that the present model is capable of predicting ferrite phase fraction and grain size with reasonable accuracy.
Model-to-model transformations of architecture descriptions of an integration platform
Directory of Open Access Journals (Sweden)
Tomasz Górski
2014-04-01
Full Text Available Model transformations play a key role in any software development project based on Mod-el-Driven Engineering (MDE principles. However, little attention has been paid to the ap-plication of MDE principles to automate the design of integration solutions. The aim of the paper is to present transformations of a model-to-model type, used to automate the process of integration platform's architecture description. The transformations have been designed to enable the generation of model elements, according to the '1+5' architectural views model adjusted to the integration solutions description. Design and implementation of transformations were performed in the IBM Rational Software Architect (RSA environ-ment. Authorial UML profiles: UML Profile for Integration Platform and UML Profile for Integration Flows have been used. The paper covers transformations between models in the following architectural views: Integrated Processes; Use Cases; Logical and Integrated Services. The transformations occur at the levels of business processes, requirements speci-fication and system design. Using the transformations, it is possible to generate models, diagrams, model elements and relationships between them. The complete environment has been obtained to automate architectural description of an integration solution. Transfor-mations ensure completeness of the architectural description and consistency of elements between models.
Energy Technology Data Exchange (ETDEWEB)
Monine, Michael [Los Alamos National Laboratory; Posner, Richard [TRANSLATION GENOMICS RESAEARCH INSTITUTE; Savage, Paul [BYU; Faeder, James [UNIV OF PITTSBURGH; Hlavacek, William S [UNM
2008-01-01
Signal transduction generally involves multivalent protein-protein interactions, which can produce various protein complexes and post-translational modifications. The reaction networks that characterize these interactions tend to be so large as to challenge conventional simulation procedures. To address this challenge, a kinetic Monte Carlo (KMC) method has been developed that can take advantage of a model specification in terms of reaction rules for molecular interactions. A set of rules implicitly defines the reactions that can occur as a result of the interactions represented by the rules. With the rule-based KMC method, explicit generation of the underlying chemical reaction network implied by rules is avoided. Here, we apply and extend this method to characterize the interactions of a trivalent ligand with a bivalent cell-surface receptor. This system is also studied experimentally. We consider the following kinetic models: an equivalent-site model, an extension of this model, which takes into account steric constraints on the configurations of receptor aggregates, and finally, a model that accounts for cyclic receptor aggregates. Simulation results for the equivalent-site model are consistent with an equilibrium continuum model. Using these models, we investigate the effects of steric constraints and the formation of cyclic aggregates on the kinetics and equilibria of small and large aggregate formation and the percolation phase transition that occurs in this system.
Carvalhais, N.; Forkel, M.; Oijen, M. V.; Keenan, T. F.; MacBean, N.; Rolinski, S.; Peylin, P. P.; Schuermann, G. J.; Zaehle, S.; Reichstein, M.
2015-12-01
The representation of exchanges of carbon, water and energy between the land surface and the atmosphere still reveals significant model limitations in explaining temporal and spatial variability. Despite agreement between models for contemporaneous periods, prognostic simulations reveal a strong between-model divergence regarding the role of the land surface in the global carbon cycle. The integration of multiple data-streams in inverse modelling approaches for parameterization and model evaluation, ultimately leads to model improvement. Here we explore multiple-constraint approaches ranging from in situ to regional and global spatial scales. Constraints include stocks and fluxes of water and carbon. We show that integrating multiple datasets contributes to a better representation of ecosystem dynamics in different models, from forest and dynamic vegetation models to land surface schemes. At site scale, model-data comparisons reveal substantial differences in the modelled temporal dynamics of carbon stocks and turnover times and their relationships with climate, especially at annual scales. Inter-annual variability remains a problem for all models, even after parameter optimization. At regional and global scales, the integration of multiple data-streams to constrain albedo, phenology and primary productivity patterns yields a significant improvement in regional simulations of vegetation dynamics, from seasons to longer-term trends. The role of environmental controls and vegetation dynamics in explaining recent trends in the amplitude of the seasonal cycle of atmospheric CO2 is evaluated using an improved dynamic vegetation model. We conclude by identifying major challenges in model-data-integration: to explore the information content in longer time series; avoid confounding effects of missing processes on parameter estimation; set up cost functions for multivariate-data integration; quantification of uncertainties arising from data bias, model structure, and
Spatial Modeling of Iron Transformations Within Artificial Soil Aggregates
Kausch, M.; Meile, C.; Pallud, C.
2008-12-01
Structured soils exhibit significant variations in transport characteristics at the aggregate scale. Preferential flow occurs through macropores while predominantly diffusive exchange takes place in intra-aggregate micropores. Such environments characterized by mass transfer limitations are conducive to the formation of small-scale chemical gradients and promote strong spatial variation in processes controlling the fate of redox-sensitive elements such as Fe. In this study, we present a reactive transport model used to spatially resolve iron bioreductive processes occurring within a spherical aggregate at the interface between advective and diffusive domains. The model is derived from current conceptual models of iron(hydr)oxide (HFO) transformations and constrained by literature and experimental data. Data were obtained from flow-through experiments on artificial soil aggregates inoculated with Shewanella putrefaciens strain CN32, and include the temporal evolution of the bulk solution composition, as well as spatial information on the final solid phase distribution within aggregates. With all iron initially in the form of ferrihydrite, spatially heterogeneous formation of goethite/lepidocrocite, magnetite and siderite was observed during the course of the experiments. These transformations were reproduced by the model, which ascribes a central role to divalent iron as a driver of HFO transformations and master variable in the rate laws of the considered reaction network. The predicted dissolved iron breakthrough curves also match the experimental ones closely. Thus, the computed chemical concentration fields help identify factors governing the observed trends in the solid phase distribution patterns inside the aggregate. Building on a mechanistic description of transformation reactions, fluid flow and solute transport, the model was able to describe the observations and hence illustrates the importance of small-scale gradients and dynamics of bioreductive
TOODM: A temporal object-oriented data model with temporal constraints
Energy Technology Data Exchange (ETDEWEB)
Rose, E.; Segev, A.
1991-04-01
A static Entity-Relationship (ER) or static Extended ER (EER) data model is not sufficient for representing the underlying time component of the data, more complex data types as found in planning, design and office automation applications or the operation required for this complex data. The decreasing cost of mass storage devices accompanied by an increased need for real-time systems and easier access to historical and planning data has made the study of the temporal aspects of data models more interesting both theoretically and practically. Furthermore, the ER-based data models can capture relationships between classes but they do not understand the object-oriented paradigm since they treat application-specific relationships and paradigm-specific relationships such as inheritance in the same manner. This shortcoming accompanied by a lack of support for the time dimension results in the specification of temporal relationships and constraints at the application level and often leads to inconsistencies in the data. In this paper, we extend the object-based ER model into a temporal, object-oriented model, incorporate temporal structures and constraints in the data model and propose a temporal, object-oriented query language for the model.
Allowing for model error in strong constraint 4D-Var
Howes, Katherine; Lawless, Amos; Fowler, Alison
2016-04-01
Four dimensional variational data assimilation (4D-Var) can be used to obtain the best estimate of the initial conditions of an environmental forecasting model, namely the analysis. In practice, when the forecasting model contains errors, the analysis from the 4D-Var algorithm will be degraded to allow for errors later in the forecast window. This work focusses on improving the analysis at the initial time by allowing for the fact that the model contains error, within the context of strong constraint 4D-Var. The 4D-Var method developed acknowledges the presence of random error in the model at each time step by replacing the observation error covariance matrix with an error covariance matrix that includes both observation error and model error statistics. It is shown that this new matrix represents the correct error statistics of the innovations in the presence of model error. A method for estimating this matrix using innovation statistics, without requiring prior knowledge of the model error statistics, is presented. The method is demonstrated numerically using a non-linear chaotic system with erroneous parameter values. We show that that the new method works to reduce the analysis error covariance when compared with a standard strong constraint 4D-Var scheme. We discuss the fact that an improved analysis will not necessarily provide a better forecast.
Model-independent constraints on hadronic form factors with above-threshold poles
Caprini, Irinel; Grinstein, Benjamín; Lebed, Richard F.
2017-08-01
Model-independent constraints on hadronic form factors, in particular those describing exclusive semileptonic decays, can be derived from the knowledge of field correlators calculated in perturbative QCD, using analyticity and unitarity. The location of poles corresponding to below-threshold resonances, i.e., stable states that cannot decay into a pair of hadrons from the crossed channel of the form factor, must be known a priori, and their effect, accounted for through the use of Blaschke factors, is to reduce the strength of the constraints in the semileptonic region. By contrast, above-threshold resonances appear as poles on unphysical Riemann sheets, and their presence does not affect the original model-independent constraints. We discuss the possibility that the above-threshold poles can provide indirect information on the form factors on the first Riemann sheet, either through information from their residues or by constraining the discontinuity function. The bounds on form factors can be improved by imposing, in an exact way, the additional information in the extremal problem. The semileptonic K →π ℓν and D →π ℓν decays are considered as illustrations.
Transforming business models through big data in the textile industry
DEFF Research Database (Denmark)
Aagaard, Annabeth
as stressed by Zott et al. (2011), Weill et al. (2011) and David J. Teece (2010: 174), who states that: “the concept of a business model lacks theoretical grounding in economics or in business studies”. With the acceleration of digitization and use of big data analytics quality data are accessible......, such as textile, and have led to disruption of established business models (Westerman et al., 2014; Weill and Woerner, 2015). Yet, little is known of the managerial process and facilitation of the digital transformation of business models through big data (McAfee and Brynjolfsson, 2012; Markus and Loebbecke, 2013)....
New Constraints on Dark Matter Effective Theories from Standard Model Loops
Crivellin, Andreas; Procura, Massimiliano
2014-01-01
We consider an effective field theory for a gauge singlet Dirac dark matter (DM) particle interacting with the Standard Model (SM) fields via effective operators suppressed by the scale $\\Lambda \\gtrsim 1$ TeV. We perform a systematic analysis of the leading loop contributions to spin-independent (SI) DM--nucleon scattering using renormalization group evolution between $\\Lambda$ and the low-energy scale probed by direct detection experiments. We find that electroweak interactions induce operator mixings such that operators that are naively velocity-suppressed and spin-dependent can actually contribute to SI scattering. This allows us to put novel constraints on Wilson coefficients that were so far poorly bounded by direct detection. Constraints from current searches are comparable to LHC bounds, and will significantly improve in the near future. Interestingly, the loop contribution we find is maximally isospin violating even if the underlying theory is isospin conserving.
Constraints to the EOS of ultradense matter with model-independent astrophysical observations
Lavagetto, G; D'Ai', A; Vidaña, I; Robba, N R
2006-01-01
The recent discovery of burst oscillations at 1122 Hz in the x-ray transient XTE J1739-285, together with the measurement of the mass of the binary millisecond pulsar PSR J0751+1807 (2.1 +- 0.2 solar masses) can finally allow us to put strong, model-independent observational constraints to the equation of state of compact stars. We show that the measurement of the moment of inertia of PSR J0737+3039A, together with these constraints, could allow to discriminate further the details of the inner structure of neutron stars. Moreover, we show that if XTE J1739-285 is constituted of nucleonic matter, any equation of state allows only a narrow range of very high masses, and this could explain why up to now compact stars spinning faster than a millisecond have been so difficult to detect.
Unitary transformation method for solving generalized Jaynes-Cummings models
Indian Academy of Sciences (India)
Sudha Singh
2006-03-01
Two fully quantized generalized Jaynes-Cummings models for the interaction of a two-level atom with radiation field are treated, one involving intensity dependent coupling and the other involving multiphoton interaction between the field and the atom. The unitary transformation method presented here not only solves the time dependent problem but also allows a determination of the eigensolutions of the interacting Hamiltonian at the same time.
A transformation model for Laminaria Japonica (Phaeophyta, Laminariales)
Qin, Song; Jiang, Peng; Li, Xin-Ping; Wang, Xi-Hua; Zeng, Cheng-Kui
1998-03-01
A genetic transformation model for the seaweed Laminaria japonica mainly includes the following aspects: 1. The method to introduce foreign genes into the kelp, L. japonica Biolistic bombardment has been proved to be an effective method to bombard foreign DNA through cell walls into intact cells of both sporophytes and gametophytes. The expression of cat and lacZ was detected in regenerated sporophytes, which suggests that this method could induce random integration of foreign genes. Promoters to drive gene expression
Coupled modified baker's transformations for the Ising model.
Sakaguchi, H
1999-12-01
An invertible coupled map lattice is proposed for the Ising model. Each elemental map is a modified baker's transformation, which is a two-dimensional map of X and Y. The time evolution of the spin variable is memorized in the binary representation of the Y variable. The temporal entropy and time correlation of the spin variable are calculated from the snapshot configuration of the Y variables.
Delle Monache, M. L.; Goatin, P.
2014-12-01
We consider a strongly coupled PDE-ODE system that describes the influence of a slow and large vehicle on road traffic. The model consists of a scalar conservation law accounting for the main traffic evolution, while the trajectory of the slower vehicle is given by an ODE depending on the downstream traffic density. The moving constraint is expressed by an inequality on the flux, which models the bottleneck created in the road by the presence of the slower vehicle. We prove the existence of solutions to the Cauchy problem for initial data of bounded variation.
Constraints from muon g-2 and LFV processes in the Higgs Triplet Model
Fukuyama, Takeshi; Tsumura, Koji
2009-01-01
Constraints from the muon anomalous magnetic dipole moment and lepton flavor violating processes are translated into lower bounds on v_Delta*m_H++ in the Higgs Triplet Model by considering correlations through the neutrino mass matrix. The discrepancy of the sign of the contribution to the muon anomalous magnetic dipole moment between the measurement and the prediction in the model is clarified. It is shown that mu to e gamma, tau decays (especially, tau to mu e e), and the muonium conversion can give a more stringent bound on v_Delta*m_H++ than the bound from mu to eee which is expected naively to give the most stringent one.
Feature, design intention and constraint preservation for direct modeling of 3D freeform surfaces
Fu, Luoting; Kara, Levent Burak; Shimada, Kenji
2012-06-01
Direct modeling has recently emerged as a suitable approach for 3D free-form shape modeling in industrial design. It has several advantages over the conventional, parametric modeling techniques, including natural user interactions, as well as the underlying, automatic feature-preserving shape deformation algorithms. However, current direct modeling packages still lack several capabilities critical for product design, such as managing aesthetic design intentions, and enforcing dimensional, geometric constraints. In this paper, we describe a novel 3D surface editing system capable of jointly accommodating aesthetic design intentions expressed in the form of surface painting and color-coded annotations, as well as engineering constraints expressed as dimensions. The proposed system is built upon differential coordinates and constrained least squares, and is intended for conceptual design that involves frequent shape tuning and explorations. We also provide an extensive review of the state-of-the-art direct modeling approaches for 3D mesh-based, freeform surfaces, with an emphasis on the two broad categories of shape deformation algorithms developed in the relevant field of geometric modeling. [Figure not available: see fulltext.
Constraints on galaxy formation models from the galaxy stellar mass function and its evolution
Rodrigues, Luiz Felippe S; Bower, Richard
2016-01-01
We explore the parameter space of the semi-analytic galaxy formation model GALFORM, studying the constraints imposed by measurements of the galaxy stellar mass function (GSMF) and its evolution. We use the Bayesian Emulator method to quickly eliminate vast implausible volumes of the parameter space and zoom in on the most interesting regions, allowing us to identify a set of models that match the observational data within the model uncertainties. We find that the GSMF strongly constrains parameters related to the quiescent star formation in discs, stellar and AGN feedback and the threshold for disc instabilities, but more weakly restricts other parameters. Constraining the model using the local data alone does not usually select models that match the evolution of the mass function well. Nevertheless, we show that a small subset of models provides an acceptable match to GSMF data out to redshift 1.5, without introducing an explicit redshift dependence of feedback parameters. We explore the physical significanc...
Chiba, T; Suto, Y; Chiba, Takashi; Sugiyama, Naoshi; Suto, Yasushi
1994-01-01
We have performed the most comprehensive predictions of the temperature fluctuations \\dtt in the primeval isocurvature baryon models to see whether or not the models are consistent with the recent data on the cosmic microwave background anisotropies. More specifically, we computed the \\dtt corresponding to the experimental set-up by the South-Pole and the Owens Valley experiments as well as the COBE satellite. The amplitudes of the predicted \\dtt are normalized by means of the COBE 10$^\\circ$ data. The resulting constraints on the models are presented on $n - \\Omega_b$ plane in the case of $\\lambda_0=1-\\Omega_b$ (flat models) and $\\lambda_0=0$ (open models), where $n$ is the primordial spectral index of entropy fluctuations and $\\Omega_b$ is the present baryon density parameter. Our results imply that the PIB models cannot be reconciled with the current observations for any reasonable set of cosmological parameters.
Modeling the coupling between martensitic phase transformation and plasticity in shape memory alloys
Manchiraju, Sivom
reflect a model limitation that transformation-plasticity coupling is captured on a coarse (grain) scale but not fine (martensitic plate) scale. Lastly, Crystallographic Theory of Martensite (CTM) and micromechanics-based modeling is applied to analyze recent TEM observations. In particular, the observation of sub-micron dislocation loops is explained in terms of the large stress generated by the phase transformation at the variant (sub-micron) scale. Second, the observation of atypical compound twin related martensite variants in TEM foils is explained in terms of the loss of constraint produced by free-surfaces.
An efficient visual saliency detection model based on Ripplet transform
Indian Academy of Sciences (India)
A DIANA ANDRUSHIA; R THANGARAJAN
2017-05-01
Even though there have been great advancements in computer vision tasks, the development of human visual attention models is still not well investigated. In day-to-day life, one can find ample applications of saliency detection in image and video processing. This paper presents an efficient visual saliency detectionmodel based on Ripplet transform, which aims at detecting the salient region and achieving higher Receiver Operating Characteristics (ROC). Initially the feature maps are obtained from Ripplet transform in different scales and different directions of the image. The global and local saliency maps are computed based on the global probability density distribution and feature distribution of local areas, which are combined together to get the final saliency map. Ripplet-transform-based visual saliency detection is the novel approach carried out in this paper. Experimental results indicate that the proposed method based on Ripplet transformation can give excellent performance in terms of precision, recall, F measure and Mean Absolute Error (MAE), and is compared with 10 state-of-the-art methods on five benchmark datasets.
Challenges in Materials Transformation Modeling for Polyolefins Industry
Lai, Shih-Yaw; Swogger, Kurt W.
2004-06-01
Unlike most published polymer processing and/or forming research, the transformation of polyolefins to fabricated articles often involves non-confined flow or so-called free surface flow (e.g. fiber spinning, blown films, and cast films) in which elongational flow takes place during a fabrication process. Obviously, the characterization and validation of extensional rheological parameters and their use to develop rheological constitutive models are the focus of polyolefins materials transformation research. Unfortunately, there are challenges that remain with limited validation for non-linear, non-isothermal constitutive models for polyolefins. Further complexity arises in the transformation of polyolefins in the elongational flow system as it involves stress-induced crystallization process. The complicated nature of elongational, non-linear rheology and non-isothermal crystallization kinetics make the development of numerical methods very challenging for the polyolefins materials forming modeling. From the product based company standpoint, the challenges of materials transformation research go beyond elongational rheology, crystallization kinetics and its numerical modeling. In order to make models useful for the polyolefin industry, it is critical to develop links between molecular parameters to both equipment and materials forming parameters. The recent advances in the constrained geometry catalysis and materials sciences understanding (INSITE technology and molecular design capability) has made industrial polyolefinic materials forming modeling more viable due to the fact that the molecular structure of the polymer can be well predicted and controlled during the polymerization. In this paper, we will discuss inter-relationship (models) among molecular parameters such as polymer molecular weight (Mw), molecular weight distribution (MWD), long chain branching (LCB), short chain branching (SCB or comonomer types and distribution) and their affects on shear and
Joint-constraint model for large-eddy simulation of helical turbulence.
Yu, Changping; Xiao, Zuoli; Shi, Yipeng; Chen, Shiyi
2014-04-01
A three-term mixed subgrid-scale (SGS) stress model is proposed for large-eddy simulation (LES) of helical turbulence. The new model includes a Smagorinsky-Lilly term, a velocity gradient term, and a symmetric vorticity gradient term. The model coefficients are determined by minimizing the mean square error between the realistic and modeled Leonard stresses under a joint constraint of kinetic energy and helicity fluxes. The model formulated as such is referred to as joint-constraint dynamic three-term model (JCD3TM). First, the new model is evaluated a priori using the direct numerical simulation (DNS) data of homogeneous isotropic turbulence with helical forcing. It is shown that the SGS dissipation fractions from all three terms in JCD3TM have the properties of length-scale invariance in inertial subrange. JCD3TM can predict the SGS stresses, energy flux, and helicity flux more accurately than the dynamic Smagorinsky model (DSM) and dynamic mixed helical model (DMHM) in both pointwise and statistical senses. Then, the performance of JCD3TM is tested a posteriori in LESs of both forced and freely decaying helical isotropic turbulence. It is found that JCD3TM possesses certain features of superiority over the other two models in predicting the energy spectrum, helicity spectrum, high-order statistics, etc. It is also noteworthy that JCD3TM is capable of simulating the evolutions of both energy and helicity spectra more precisely than other models in decaying helical turbulence. We claim that the present SGS model can capture the main helical features of turbulent motions and may serve as a useful tool for LES of helical turbulent flows.
Directory of Open Access Journals (Sweden)
Mei Lin Neo
Full Text Available Recruitment constraints on Singapore's dwindling fluted giant clam, Tridacna squamosa, population were studied by modelling fertilisation, larval transport, and settlement using real-time hydrodynamic forcing combined with knowledge of spawning characteristics, larval development, behaviour, and settlement cues. Larval transport was simulated using a finite-volume advection-diffusion model coupled to a three-dimensional hydrodynamic model. Three recruitment constraint hypotheses were tested: 1 there is limited connectivity between Singapore's reefs and other reefs in the region, 2 there is limited exchange within Singapore's Southern Islands, and 3 there exist low-density constraints to fertilisation efficacy (component Allee effects. Results showed that connectivity among giant clam populations was primarily determined by residual hydrodynamic flows and spawning time, with greatest chances of successful settlement occurring when spawning and subsequent larval dispersal coincided with the period of lowest residual flow. Simulations suggested poor larval transport from reefs located along the Peninsular Malaysia to Singapore, probably due to strong surface currents between the Andaman Sea and South China Sea combined with a major land barrier disrupting larval movement among reefs. The model, however, predicted offshore coral reefs to the southeast of Singapore (Bintan and Batam may represent a significant source of larvae. Larval exchange within Singapore's Southern Islands varied substantially depending on the locations of source and sink reefs as well as spawning time; but all simulations resulted in low settler densities (2.1-68.6 settled individuals per 10,000 m(2. Poor fertilisation rates predicted by the model indicate that the low density and scattered distribution of the remaining T. squamosa in Singapore are likely to significantly inhibit any natural recovery of local stocks.
Directory of Open Access Journals (Sweden)
I. V. Novash
2015-01-01
Full Text Available This article describes the parameters calculation for the three-phase two-winding power transformer model taken from the SimPowerSystems library, which is the part of the MatLab- Simulink environment. Presented methodology is based on the power transformer nameplate data usage. Particular attention is paid to the power transformer magnetization curve para- meters calculation. The methodology of the three-phase two-winding power transformer model parameters calculation considering the magnetization curve nonlinearity isn’t presented in Russian-and English-language sources. Power transformers demo models described in the SimPowerSystems user’s guide have already calculated parameters, but without reference to the sources of their determination. A power transformer is a nonlinear element of the power system, that’s why for its performance analysis in different modes of operation is necessary to have the magnetization curve parameters.The process analysis during no-load energizing of the power transformer is of special interest. This regime is accompanied by the inrush current on the supply side of the power transformer, which is several times larger than the transformer rated current. Sharp rising of the magnetizing current is explained by the magnetic core saturation. Therefore, magnetiza- tion characteristic accounting during transformer no-load energizing modeling is a mandatory requirement. Article authors attempt to put all calculating formulas in a more convenient form and validate the power transformer nonlinear magnetization characteristics parameters calcu- lation. Inrush current oscillograms obtained during the simulation experiment confirmed the adequacy of the calculated model parameters.
Directory of Open Access Journals (Sweden)
Cotten Cameron
2013-01-01
Full Text Available Abstract Background Constraint-based modeling uses mass balances, flux capacity, and reaction directionality constraints to predict fluxes through metabolism. Although transcriptional regulation and thermodynamic constraints have been integrated into constraint-based modeling, kinetic rate laws have not been extensively used. Results In this study, an in vivo kinetic parameter estimation problem was formulated and solved using multi-omic data sets for Escherichia coli. To narrow the confidence intervals for kinetic parameters, a series of kinetic model simplifications were made, resulting in fewer kinetic parameters than the full kinetic model. These new parameter values are able to account for flux and concentration data from 20 different experimental conditions used in our training dataset. Concentration estimates from the simplified kinetic model were within one standard deviation for 92.7% of the 790 experimental measurements in the training set. Gibbs free energy changes of reaction were calculated to identify reactions that were often operating close to or far from equilibrium. In addition, enzymes whose activities were positively or negatively influenced by metabolite concentrations were also identified. The kinetic model was then used to calculate the maximum and minimum possible flux values for individual reactions from independent metabolite and enzyme concentration data that were not used to estimate parameter values. Incorporating these kinetically-derived flux limits into the constraint-based metabolic model improved predictions for uptake and secretion rates and intracellular fluxes in constraint-based models of central metabolism. Conclusions This study has produced a method for in vivo kinetic parameter estimation and identified strategies and outcomes of kinetic model simplification. We also have illustrated how kinetic constraints can be used to improve constraint-based model predictions for intracellular fluxes and biomass
Cotten, Cameron; Reed, Jennifer L
2013-01-30
Constraint-based modeling uses mass balances, flux capacity, and reaction directionality constraints to predict fluxes through metabolism. Although transcriptional regulation and thermodynamic constraints have been integrated into constraint-based modeling, kinetic rate laws have not been extensively used. In this study, an in vivo kinetic parameter estimation problem was formulated and solved using multi-omic data sets for Escherichia coli. To narrow the confidence intervals for kinetic parameters, a series of kinetic model simplifications were made, resulting in fewer kinetic parameters than the full kinetic model. These new parameter values are able to account for flux and concentration data from 20 different experimental conditions used in our training dataset. Concentration estimates from the simplified kinetic model were within one standard deviation for 92.7% of the 790 experimental measurements in the training set. Gibbs free energy changes of reaction were calculated to identify reactions that were often operating close to or far from equilibrium. In addition, enzymes whose activities were positively or negatively influenced by metabolite concentrations were also identified. The kinetic model was then used to calculate the maximum and minimum possible flux values for individual reactions from independent metabolite and enzyme concentration data that were not used to estimate parameter values. Incorporating these kinetically-derived flux limits into the constraint-based metabolic model improved predictions for uptake and secretion rates and intracellular fluxes in constraint-based models of central metabolism. This study has produced a method for in vivo kinetic parameter estimation and identified strategies and outcomes of kinetic model simplification. We also have illustrated how kinetic constraints can be used to improve constraint-based model predictions for intracellular fluxes and biomass yield and identify potential metabolic limitations through the
Model-free prediction and regression a transformation-based approach to inference
Politis, Dimitris N
2015-01-01
The Model-Free Prediction Principle expounded upon in this monograph is based on the simple notion of transforming a complex dataset to one that is easier to work with, e.g., i.i.d. or Gaussian. As such, it restores the emphasis on observable quantities, i.e., current and future data, as opposed to unobservable model parameters and estimates thereof, and yields optimal predictors in diverse settings such as regression and time series. Furthermore, the Model-Free Bootstrap takes us beyond point prediction in order to construct frequentist prediction intervals without resort to unrealistic assumptions such as normality. Prediction has been traditionally approached via a model-based paradigm, i.e., (a) fit a model to the data at hand, and (b) use the fitted model to extrapolate/predict future data. Due to both mathematical and computational constraints, 20th century statistical practice focused mostly on parametric models. Fortunately, with the advent of widely accessible powerful computing in the late 1970s, co...
Lithium abundance and surface magnetic fields: new constraints in magnetic models of M dwarfs
MacDonald, James
2013-01-01
Precision modeling of M dwarfs has become worthwhile in recent years due to the increasingly precise values of masses and radii which can be obtained from eclipsing binary studies. Torres (2013) has identified 4 prime M dwarf pairs with the most precise empirical determinations of masses and radii. The measured radii are consistently larger than standard stellar models predict. We have previously modeled M dwarfs in the context of a criterion due to Gough & Tayler in which magnetic fields inhibit the onset of convection according to a physics-based prescription. New constraints on the models of M dwarfs are now provided by measurements of lithium abundances. The key aspect of Li in terms of setting constraints on magnetic modeling is that Li burning starts at T = 2.5 MK, and temperatures of just such magnitude are associated with the base of the convection zone: magnetic inhibition of convective onset can shift this base slightly closer to the surface, i.e. to slightly lower temperatures, thereby reducing...
Human Hand Kinematic Modeling Based on Robotic Concepts for Digit Animation with Dynamic Constraints
Tondu, Bertrand
The recent development of highly anthropomorphic avatars in computer graphics has emphasized the importance of accurate hand kinematic models. Although kinematic methods derived from robotics have recently been applied to the modeling of hands, we consider that original/new and relevant results can be brought into play with the use of more advanced applications of robotic techniques to human hand kinematic modeling. Our chapter analyses some of these questions both in the non-differential and differential fields. More specifically, we study how to integrate the peculiar natural digit movement constraints into robotics-based inverse kinematic modeling. As a result, we propose an original approach based on an interpretation of each joint dynamic constraint as a linear joint synergy. This leads to defining the considered digit as a serial chain kinematically redundant in position and reducing the dimension of its joint space by associated joint synergies. The method is applied to the Cartesian positioning simulation of a 4 d.o.f. index model; a comparison with a Jacobian pseudo-inverse-based approach emphasizes its relevance.
Constraints on galaxy formation models from the galaxy stellar mass function and its evolution
Rodrigues, Luiz Felippe S.; Vernon, Ian; Bower, Richard G.
2017-04-01
We explore the parameter space of the semi-analytic galaxy formation model GALFORM, studying the constraints imposed by measurements of the galaxy stellar mass function (GSMF) and its evolution. We use the Bayesian emulator method to quickly eliminate vast implausible volumes of the parameter space and zoom in on the most interesting regions, allowing us to identify a set of models that match the observational data within model uncertainties. We find that the GSMF strongly constrains parameters related to quiescent star formation in discs, stellar and active galactic nucleus feedback and threshold for disc instabilities, but weakly restricts other parameters. Constraining the model using local data alone does not usually select models that match the evolution of the GSMF well. Nevertheless, we show that a small subset of models provides acceptable match to GSMF data out to redshift 1.5. We explore the physical significance of the parameters of these models, in particular exploring whether the model provides a better description if the mass loading of the galactic winds generated by starbursts (β0,burst) and quiescent discs (β0,disc) is different. Performing a principal component analysis of the plausible volume of the parameter space, we write a set of relations between parameters obeyed by plausible models with respect to GSMF evolution. We find that while β0,disc is strongly constrained by GSMF evolution data, constraints on β0,burst are weak. Although it is possible to find plausible models for which β0,burst = β0,disc, most plausible models have β0,burst > β0,disc, implying - for these - larger stellar feedback efficiency at higher redshifts.
APPLYING BLACK-BOX TESTING TO MODEL TRANSFORMATIONS IN THE MODEL DRIVEN ARCHITECTURE CONTEXT
Directory of Open Access Journals (Sweden)
Luciane Telinski Wiedermann Agner
2014-01-01
Full Text Available Testing model transformations has played a leading role with the dissemination of MDA in software development processes. Software testing based on black-box testing, together with the “category partitioning” method, can be efficiently used in order to conduct the verification of model transformations. This study employs software testing techniques to an ATL model transformation in the MDA context and points out their benefits. The black-box testing method was adapted to the MT-PROAPES model transformation based on profiles and platform models. The platform models define the range of input models of the MT-PROAPES and are used for the creation of the test cases. The test cases were selected so as to meet certain requirements and increase the ability to detect errors in the model transformation. This approach makes the test process more agile and does not require any abstraction of behavioral properties of the transformations. The field of transformation testing and verification still faces significant challenges and requires a lot of research. Although having some limitations, black-box testing conforms to various situations, besides allowing its integration with other test strategies.
A Novel Method for Optimal Solution of Fuzzy Chance Constraint Single-Period Inventory Model
Directory of Open Access Journals (Sweden)
Anuradha Sahoo
2016-01-01
Full Text Available A method is proposed for solving single-period inventory fuzzy probabilistic model (SPIFPM with fuzzy demand and fuzzy storage space under a chance constraint. Our objective is to maximize the total profit for both overstock and understock situations, where the demand D~j for each product j in the objective function is considered as a fuzzy random variable (FRV and with the available storage space area W~, which is also a FRV under normal distribution and exponential distribution. Initially we used the weighted sum method to consider both overstock and understock situations. Then the fuzziness of the model is removed by ranking function method and the randomness of the model is removed by chance constrained programming problem, which is a deterministic nonlinear programming problem (NLPP model. Finally this NLPP is solved by using LINGO software. To validate and to demonstrate the results of the proposed model, numerical examples are given.
Directory of Open Access Journals (Sweden)
Javier Macias-Guarasa
2012-10-01
Full Text Available This paper presents a novel approach for indoor acoustic source localization using sensor arrays. The proposed solution starts by defining a generative model, designed to explain the acoustic power maps obtained by Steered Response Power (SRP strategies. An optimization approach is then proposed to fit the model to real input SRP data and estimate the position of the acoustic source. Adequately fitting the model to real SRP data, where noise and other unmodelled effects distort the ideal signal, is the core contribution of the paper. Two basic strategies in the optimization are proposed. First, sparse constraints in the parameters of the model are included, enforcing the number of simultaneous active sources to be limited. Second, subspace analysis is used to filter out portions of the input signal that cannot be explained by the model. Experimental results on a realistic speech database show statistically significant localization error reductions of up to 30% when compared with the SRP-PHAT strategies.
Analysis report for WIPP colloid model constraints and performance assessment parameters
Energy Technology Data Exchange (ETDEWEB)
Mariner, Paul E.; Sassani, David Carl
2014-03-01
An analysis of the Waste Isolation Pilot Plant (WIPP) colloid model constraints and parameter values was performed. The focus of this work was primarily on intrinsic colloids, mineral fragment colloids, and humic substance colloids, with a lesser focus on microbial colloids. Comments by the US Environmental Protection Agency (EPA) concerning intrinsic Th(IV) colloids and Mg-Cl-OH mineral fragment colloids were addressed in detail, assumptions and data used to constrain colloid model calculations were evaluated, and inconsistencies between data and model parameter values were identified. This work resulted in a list of specific conclusions regarding model integrity, model conservatism, and opportunities for improvement related to each of the four colloid types included in the WIPP performance assessment.
Tulchinsky, Alexander Y; Johnson, Norman A; Porter, Adam H
2014-12-01
Hybrid incompatibility can result from gene misregulation produced by divergence in trans-acting regulatory factors and their cis-regulatory targets. However, change in trans-acting factors may be constrained by pleiotropy, which would in turn limit the evolution of incompatibility. We employed a mechanistically explicit bioenergetic model of gene expression wherein parameter combinations (number of transcription factor molecules, energetic properties of binding to the regulatory site, and genomic background size) determine the shape of the genotype-phenotype (G-P) map, and interacting allelic variants of mutable cis and trans sites determine the phenotype along that map. Misregulation occurs when the phenotype differs from its optimal value. We simulated a pleiotropic regulatory pathway involving a positively selected and a conserved trait regulated by a shared transcription factor (TF), with two populations evolving in parallel. Pleiotropic constraints shifted evolution in the positively selected trait to its cis-regulatory locus. We nevertheless found that the TF genotypes often evolved, accompanied by compensatory evolution in the conserved trait, and both traits contributed to hybrid misregulation. Compensatory evolution resulted in "developmental system drift," whereby the regulatory basis of the conserved phenotype changed although the phenotype itself did not. Pleiotropic constraints became stronger and in some cases prohibitive when the bioenergetic properties of the molecular interaction produced a G-P map that was too steep. Likewise, compensatory evolution slowed and hybrid misregulation was not evident when the G-P map was too shallow. A broad pleiotropic "sweet spot" nevertheless existed where evolutionary constraints were moderate to weak, permitting substantial hybrid misregulation in both traits. None of these pleiotropic constraints manifested when the TF contained nonrecombining domains independently regulating the respective traits. Copyright
Transformations among CE–CVM model parameters for multicomponent systems
Indian Academy of Sciences (India)
B Nageswara Sarma; Shrikant Lele
2005-06-01
In the development of thermodynamic databases for multicomponent systems using the cluster expansion–cluster variation methods, we need to have a consistent procedure for expressing the model parameters (CECs) of a higher order system in terms of those of the lower order subsystems and to an independent set of parameters which exclusively represent interactions of the higher order systems. Such a procedure is presented in detail in this communication. Furthermore, the details of transformations required to express the model parameters in one basis from those defined in another basis for the same system are also presented.
Transforming PLC Programs into Formal Models for Verification Purposes
Darvas, D; Blanco, E
2013-01-01
Most of CERN’s industrial installations rely on PLC-based (Programmable Logic Controller) control systems developed using the UNICOS framework. This framework contains common, reusable program modules and their correctness is a high priority. Testing is already applied to find errors, but this method has limitations. In this work an approach is proposed to transform automatically PLC programs into formal models, with the goal of applying formal verification to ensure their correctness. We target model checking which is a precise, mathematical-based method to check formalized requirements automatically against the system.
Dynamic modeling and simulation of power transformer maintenance costs
Directory of Open Access Journals (Sweden)
Ristić Olga
2016-01-01
Full Text Available The paper presents the dynamic model of maintenance costs of the power transformer functional components. Reliability is modeled combining the exponential and Weibull's distribution. The simulation was performed with the aim of corrective maintenance and installation of the continuous monitoring system of the most critical components. Simulation Dynamic System (SDS method and VENSIM PLE software was used to simulate the cost. In this way, significant savings in maintenance costs will be achieved with a small initial investment. [Projekat Ministarstva nauke Republike Srbije, br. III 41025 i br. OI 171007
A biofilm model for prediction of pollutant transformation in sewers.
Jiang, Feng; Leung, Derek Hoi-Wai; Li, Shiyu; Chen, Guang-Hao; Okabe, Satoshi; van Loosdrecht, Mark C M
2009-07-01
This study developed a new sewer biofilm model to simulate the pollutant transformation and biofilm variation in sewers under aerobic, anoxic and anaerobic conditions. The biofilm model can describe the activities of heterotrophic, autotrophic, and sulfate-reducing bacteria (SRB) in the biofilm as well as the variations in biofilm thickness, the spatial profiles of SRB population and biofilm density. The model can describe dynamic biofilm growth, multiple biomass evolution and competitions among organic oxidation, denitrification, nitrification, sulfate reduction and sulfide oxidation in a heterogeneous biofilm growing in a sewer. The model has been extensively verified by three different approaches, including direct verification by measurement of the spatial concentration profiles of dissolved oxygen, nitrate, ammonia, and hydrogen sulfide in sewer biofilm. The spatial distribution profile of SRB in sewer biofilm was determined from the fluorescent in situ hybridization (FISH) images taken by a confocal laser scanning microscope (CLSM) and were predicted well by the model.
Pessimistic Predicate/Transform Model for Long Running Business Processes
Institute of Scientific and Technical Information of China (English)
WANG Jinling; JIN Beihong; LI Jing
2005-01-01
Many business processes in enterprise applications are both long running and transactional in nature. However, no current transaction model can provide full transaction support for such long running business processes. This paper proposes a new transaction model, the pessimistic predicate/transform (PP/T) model, which can provide full transaction support for long running business processes. A framework was proposed on the enterprise JavaBeans platform to implement the PP/T model. The framework enables application developers to focus on the business logic, with the underlying platform providing the required transactional semantics. The development and maintenance effort are therefore greatly reduced. Simulations show that the model has a sound concurrency management ability for long running business processes.
Constructing the barley model for genetic transformation in Triticeae
Institute of Scientific and Technical Information of China (English)
LÜ Bo; WU Jia-jie; FU Dao-lin
2015-01-01
Barley (Hordeum vulgare L.) is one of the oldest domesticated crops, showing dramatic adaptation to various climate and environmental conditions. As a major cereal crop, barley ranks the 4th after wheat, maize and rice in terms of planting area and production al over the world. Due to its diploid nature, the cultivated barley is considered as an ideal model to study the polyploid wheat and other Triticeae species. Here, we reviewed the development, optimization, and application of transgenic approaches in barley. The most efifcient and robust genetic transformation has been built on the Agrobacterium-mediated transfer in conjunction with the immature embryo-based regeneration. We then discussed future considerations of using more practical technologies in barley transformation, such as the T-DNA/transposon tagging and the genome editing. As a cereal crop amenable to genetic transformation, barley wil serve as the most valuable carrier for global functional genomics in Triticeae and is becoming the most practical model for generating value-added products.
Chatzinikos, Miltiadis; Dermanis, Athanasios
2016-11-01
By considering a deformable geodetic network, deforming in a linear-in-time mode, according to a coordinate-invariant model, it becomes possible to get an insight into the rank deficiency of the stacking procedure, which is the standard method for estimating initial station coordinates and constant velocities, from coordinate time series. Comparing any two out of the infinitely many least squares estimates of stacking unknowns (initial station coordinates, velocity components and transformation parameters for the reference system in each data epoch), it is proven that the two solutions differ only by a linear-in-time trend in the transformation parameters. These pass over to the initial coordinates (the constant term) and to the velocity estimates (the time coefficient part). While the difference in initial coordinates is equivalent to a change of the reference system at the initial epoch, the differences in velocity components do not comply with those predicted by the same change of reference system for all epochs. Consequently, the different velocity component estimates, obtained by introducing different sets of minimal constraints, correspond to physically different station velocities, which are therefore non-estimable quantities. The theoretical findings are numerically verified for a global, a regional and a local network, by obtaining solutions based on four different types of minimal constraints, three usual algebraic ones (inner or partial inner) and the lately introduced kinematic constraints. Finally, by resorting to the basic ideas of Felix Tisserand, it is explained why the station velocities are non-estimable quantities in a very natural way. The problem of the optimal choice of minimal constraints and, hence, of the corresponding spatio-temporal reference system is shortly discussed.
Chatzinikos, Miltiadis; Dermanis, Athanasios
2017-04-01
By considering a deformable geodetic network, deforming in a linear-in-time mode, according to a coordinate-invariant model, it becomes possible to get an insight into the rank deficiency of the stacking procedure, which is the standard method for estimating initial station coordinates and constant velocities, from coordinate time series. Comparing any two out of the infinitely many least squares estimates of stacking unknowns (initial station coordinates, velocity components and transformation parameters for the reference system in each data epoch), it is proven that the two solutions differ only by a linear-in-time trend in the transformation parameters. These pass over to the initial coordinates (the constant term) and to the velocity estimates (the time coefficient part). While the difference in initial coordinates is equivalent to a change of the reference system at the initial epoch, the differences in velocity components do not comply with those predicted by the same change of reference system for all epochs. Consequently, the different velocity component estimates, obtained by introducing different sets of minimal constraints, correspond to physically different station velocities, which are therefore non-estimable quantities. The theoretical findings are numerically verified for a global, a regional and a local network, by obtaining solutions based on four different types of minimal constraints, three usual algebraic ones (inner or partial inner) and the lately introduced kinematic constraints. Finally, by resorting to the basic ideas of Felix Tisserand, it is explained why the station velocities are non-estimable quantities in a very natural way. The problem of the optimal choice of minimal constraints and, hence, of the corresponding spatio-temporal reference system is shortly discussed.
Transformative Professional Development: A Model for Urban Science Education Reform
Johnson, Carla C.; Marx, Sherry
2009-04-01
This study presents a model of Transformative Professional Development (TPD) for use in sustained, collaborative, professional development of teachers in urban middle school science. TPD focuses on urban science teacher change and is responsive to school climate, teacher needs, and teacher beliefs with the intention of promoting change in practice. In this study, TPD was used to meet the needs of individual teachers and the collective needs of schools in reform efforts. The experiences of the eight teachers engaged in this process of professional growth, including their changes in practices and beliefs, provide the focus of this paper. Findings in this study revealed that through the use of TPD, participants in this study improved science teaching effectiveness and began to transform their negative school climate and create positive classroom learning environments.
Neural Network based Modeling and Simulation of Transformer Inrush Current
Directory of Open Access Journals (Sweden)
Puneet Kumar Singh
2012-05-01
Full Text Available Inrush current is a very important phenomenon which occurs during energization of transformer at no load due to temporary over fluxing. It depends on several factors like magnetization curve, resistant and inductance of primary winding, supply frequency, switching angle of circuit breaker etc. Magnetizing characteristics of core represents nonlinearity which requires improved nonlinearity solving technique to know the practical behavior of inrush current. Since several techniques still working on modeling of transformer inrush current but neural network ensures exact modeling with experimental data. Therefore, the objective of this study was to develop an Artificial Neural Network (ANN model based on data of switching angle and remanent flux for predicting peak of inrush current. Back Propagation with Levenberg-Marquardt (LM algorithm was used to train the ANN architecture and same was tested for the various data sets. This research work demonstrates that the developed ANN model exhibits good performance in prediction of inrush current’s peak with an average of percentage error of -0.00168 and for modeling of inrush current with an average of percentage error of -0.52913.
Model-independent indirect detection constraints on hidden sector dark matter
Energy Technology Data Exchange (ETDEWEB)
Elor, Gilly; Rodd, Nicholas L.; Slatyer, Tracy R.; Xue, Wei [Center for Theoretical Physics, Massachusetts Institute of Technology,77 Massachusetts Ave, Cambridge, MA 02139 (United States)
2016-06-10
If dark matter inhabits an expanded “hidden sector”, annihilations may proceed through sequential decays or multi-body final states. We map out the potential signals and current constraints on such a framework in indirect searches, using a model-independent setup based on multi-step hierarchical cascade decays. While remaining agnostic to the details of the hidden sector model, our framework captures the generic broadening of the spectrum of secondary particles (photons, neutrinos, e{sup +}e{sup −} and p-barp) relative to the case of direct annihilation to Standard Model particles. We explore how indirect constraints on dark matter annihilation limit the parameter space for such cascade/multi-particle decays. We investigate limits from the cosmic microwave background by Planck, the Fermi measurement of photons from the dwarf galaxies, and positron data from AMS-02. The presence of a hidden sector can change the constraints on the dark matter by up to an order of magnitude in either direction (although the effect can be much smaller). We find that generally the bound from the Fermi dwarfs is most constraining for annihilations to photon-rich final states, while AMS-02 is most constraining for electron and muon final states; however in certain instances the CMB bounds overtake both, due to their approximate independence on the details of the hidden sector cascade. We provide the full set of cascade spectra considered here as publicly available code with examples at http://web.mit.edu/lns/research/CascadeSpectra.html.
Benton, E. R.
1986-01-01
A spherical harmonic representation of the geomagnetic field and its secular variation for epoch 1980, designated GSFC(9/84), is derived and evaluated. At three epochs (1977.5, 1980.0, 1982.5) this model incorporates conservation of magnetic flux through five selected patches of area on the core/mantle boundary bounded by the zero contours of vertical magnetic field. These fifteen nonlinear constraints are included like data in an iterative least squares parameter estimation procedure that starts with the recently derived unconstrained field model GSFC (12/83). Convergence is approached within three iterations. The constrained model is evaluated by comparing its predictive capability outside the time span of its data, in terms of residuals at magnetic observatories, with that for the unconstrained model.
Structure Formation in a Variable Dark Energy Model and Observational Constraints
Arbabi-Bidgoli, S.; Movahed, M. S.
The interpretation of a vast number of cosmological observations in the framework of FRW models suggests that the major part of the energy density of the universe is in form of dark energy with still unknown physical nature. In some models for dark energy, which are motivated by particle physics theory, the equation of state and the contribution of dark energy to the energy density of the universe can be variable. Here we study structure formation in a parameterized dark energy model, and compare its predictions with recent observational data, from the Supernova Ia gold sample and the parameters of large scale structure determined by the 2-degree Field Galaxy Redshift Survey (2dFGRS), and put some constraints on the free parameters of this model.
Constraints on Disks Models of The Big Blue Bump from UV/Optical/IR Observations
Antonucci, R
1998-01-01
Optical/UV observations provide many constraints on accretion disk models of AGN which aren't always appreciated by modelers of the X-ray emission (or sometimes even of the optical/UV emission). The spectral behavior at the Ly edge, the polarization, the continuum slopes and breaks, and the variability timescales and phasing all conflict with simple models and strongly constrain the more Baroque ones. Partial-covering absorbers and microlensing data suggest that the radiation is not released simply according to where the potential drop (modified by standard viscous transport) takes place. On the other hand, the orientation-based unified model is in accord with the K-\\alpha inclination distributions for the AGN spectral classes, basing the latter on the limited existing data and theoretical understanding.
CP violating Two-Higgs-Doublet Model: constraints and LHC predictions
Energy Technology Data Exchange (ETDEWEB)
Keus, Venus [Department of Physics and Helsinki Institute of Physics,University of Helsinki, Gustaf Hallstromin katu 2, FIN-00014 (Finland); School of Physics and Astronomy, University of Southampton,Southampton, SO17 1BJ (United Kingdom); King, Stephen F. [School of Physics and Astronomy, University of Southampton,Southampton, SO17 1BJ (United Kingdom); Moretti, Stefano [School of Physics and Astronomy, University of Southampton,Southampton, SO17 1BJ (United Kingdom); Particle Physics Department, Rutherford Appleton Laboratory,Chilton, Didcot, Oxon OX11 0QX (United Kingdom); Yagyu, Kei [School of Physics and Astronomy, University of Southampton,Southampton, SO17 1BJ (United Kingdom)
2016-04-08
Two-Higgs-Doublet Models (2HDMs) are amongst the simplest extensions of the Standard Model. Such models allow for tree-level CP Violation (CPV) in the Higgs sector. We analyse a class of CPV 2HDM (of Type-I) in which only one of the two Higgs doublets couples to quarks and leptons, avoiding dangerous Flavour Changing Neutral Currents. We provide an up to date and comprehensive analysis of the constraints and Large Hadron Collider (LHC) predictions of such a model. Of immediate interest to the LHC Run 2 is the golden channel where all three neutral Higgs bosons are observed to decay into gauge boson pairs, WW and ZZ, providing a smoking gun signature of the CPV 2HDM.
CP Violating Two-Higgs-Doublet Model: Constraints and LHC Predictions
Keus, Venus; Moretti, Stefano; Yagyu, Kei
2015-01-01
Two-Higgs-Doublet Models (2HDMs) are amongst the simplest extensions of the Standard Model. Such models allow for tree-level CP Violation (CPV) in the Higgs sector. We analyse a class of CPV 2HDM (of Type-I) in which only one of the two Higgs doublets couples to quarks and leptons, avoiding dangerous Flavour Changing Neutral Currents. We provide an up to date and comprehensive analysis of the constraints and Large Hadron Collider (LHC) predictions of such a model. Of immediate interest to the LHC Run 2 is the golden channel where all three neutral Higgs bosons are observed to decay into gauge boson pairs, $WW$ and $ZZ$, providing a smoking gun signature of the CPV 2HDM.
Ultraviolet, Optical, and Infrared Constraints on Models of Stellar Populations and Dust Attenuation
Johnson, Benjamin D; Seibert, Mark; Treyer, Marie; Martin, D Christopher; Barlow, Tom A; Forster, Karl; Friedman, Peter G; Morrissey, Patrick; Neff, Susan G; Small, Todd; Wyder, Ted K; Bianchi, Luciana; Donas, Jose; Heckman, Timothy M; Lee, Young-Wook; Madore, Barry F; Milliard, Bruno; Rich, R Michael; Szalay, A S; Welsh, Barry Y; Yi, Sukyoung K
2007-01-01
The color of galaxies is a fundamental property, easily measured, that constrains models of galaxies and their evolution. Dust attenuation and star formation history (SFH) are the dominant factors affecting the color of galaxies. Here we explore the empirical relation between SFH, attenuation, and color for a wide range of galaxies, including early types. These galaxies have been observed by GALEX, SDSS, and Spitzer, allowing the construction of measures of dust attenuation from the ratio of infrared (IR) to ultraviolet (UV) flux and measures of SFH from the strength of the 4000A break. The empirical relation between these three quantities is compared to models that separately predict the effects of dust and SFH on color. This comparison demonstrates the quantitative consistency of these simple models with the data and hints at the power of multiwavelength data for constraining these models. The UV color is a strong constraint; we find that a Milky Way extinction curve is disfavored, and that the UV emission ...
Current status of the Standard Model CKM fit and constraints on $\\Delta F=2$ New Physics
Charles, J; Descotes-Genon, S; Lacker, H; Menzel, A; Monteil, S; Niess, V; Ocariz, J; Orloff, J; Perez, A; Qian, W; Tisserand, V; Trabelsi, K; Urquijo, P; Silva, L Vale
2015-01-01
This letter summarises the status of the global fit of the CKM parameters within the Standard Model performed by the CKMfitter group. Special attention is paid to the inputs for the CKM angles $\\alpha$ and $\\gamma$ and the status of $B_s\\to\\mu\\mu$ and $B_d\\to \\mu\\mu$ decays. We illustrate the current situation for other unitarity triangles. We also discuss the constraints on generic $\\Delta F=2$ New Physics. All results have been obtained with the CKMfitter analysis package, featuring the frequentist statistical approach and using Rfit to handle theoretical uncertainties.
Institute of Scientific and Technical Information of China (English)
Xu Zhang; En-min Feng
2004-01-01
This paper studies the two-dimensional layout optimization problem.An optimization model with performance constraints is presented.The layout problem is partitioned intofinite subproblems in terms of graph theory,in such a way of that each subproblem overcomes its on-o inature optimal variable.A minimax problem is constructed that is locally equivalent to each subproblem.By using this minimax problem,we present the optimality function for every subproblem and prove that the first order necessary optimality condition is satisfied at a point if and only if this point is a zero of optimality function.
Testing Lorentz violation with binary pulsars: constraints on standard model extension
Institute of Scientific and Technical Information of China (English)
Yi Xie
2013-01-01
Under the standard model extension (SME) framework,Lorentz invariance is tested in five binary pulsars:PSR J0737-3039,PSR B 1534+ 12,PSR J 1756-2251,PSR B1913+16 and PSR B2127+11C.By analyzing the advance of periastron,we obtain the constraints on a dimensionless combination of SME parameters that is sensitive to timing observations.The results imply no evidence for the break of Lorentz invariance at the 10-10 level,one order of magnitude larger than the previous estimation.
Comparison of Parameter Estimation Methods for Transformer Weibull Lifetime Modelling
Institute of Scientific and Technical Information of China (English)
ZHOU Dan; LI Chengrong; WANG Zhongdong
2013-01-01
Two-parameter Weibull distribution is the most widely adopted lifetime model for power transformers.An appropriate parameter estimation method is essential to guarantee the accuracy of a derived Weibull lifetime model.Six popular parameter estimation methods (i.e.the maximum likelihood estimation method,two median rank regression methods including the one regressing X on Y and the other one regressing Y on X,the Kaplan-Meier method,the method based on cumulative hazard plot,and the Li's method) are reviewed and compared in order to find the optimal one that suits transformer's Weibull lifetime modelling.The comparison took several different scenarios into consideration:10 000 sets of lifetime data,each of which had a sampling size of 40 ～ 1 000 and a censoring rate of 90％,were obtained by Monte-Carlo simulations for each scienario.Scale and shape parameters of Weibull distribution estimated by the six methods,as well as their mean value,median value and 90％ confidence band are obtained.The cross comparison of these results reveals that,among the six methods,the maximum likelihood method is the best one,since it could provide the most accurate Weibull parameters,i.e.parameters having the smallest bias in both mean and median values,as well as the shortest length of the 90％ confidence band.The maximum likelihood method is therefore recommended to be used over the other methods in transformer Weibull lifetime modelling.
Escudero, Miguel; Hooper, Dan; Witte, Samuel J.
2017-02-01
Utilizing an exhaustive set of simplified models, we revisit dark matter scenarios potentially capable of generating the observed Galactic Center gamma-ray excess, updating constraints from the LUX and PandaX-II experiments, as well as from the LHC and other colliders. We identify a variety of pseudoscalar mediated models that remain consistent with all constraints. In contrast, dark matter candidates which annihilate through a spin-1 mediator are ruled out by direct detection constraints unless the mass of the mediator is near an annihilation resonance, or the mediator has a purely vector coupling to the dark matter and a purely axial coupling to Standard Model fermions. All scenarios in which the dark matter annihilates through t-channel processes are now ruled out by a combination of the constraints from LUX/PandaX-II and the LHC.
Energy Technology Data Exchange (ETDEWEB)
Escudero, Miguel [Valencia U., IFIC; Hooper, Dan [Fermilab; Witte, Samuel J. [UCLA
2017-02-20
Utilizing an exhaustive set of simplified models, we revisit dark matter scenarios potentially capable of generating the observed Galactic Center gamma-ray excess, updating constraints from the LUX and PandaX-II experiments, as well as from the LHC and other colliders. We identify a variety of pseudoscalar mediated models that remain consistent with all constraints. In contrast, dark matter candidates which annihilate through a spin-1 mediator are ruled out by direct detection constraints unless the mass of the mediator is near an annihilation resonance, or the mediator has a purely vector coupling to the dark matter and a purely axial coupling to Standard Model fermions. All scenarios in which the dark matter annihilates through $t$-channel processes are now ruled out by a combination of the constraints from LUX/PandaX-II and the LHC.
TP-model transformation-based-control design frameworks
Baranyi, Péter
2016-01-01
This book covers new aspects and frameworks of control, design, and optimization based on the TP model transformation and its various extensions. The author outlines the three main steps of polytopic and LMI based control design: 1) development of the qLPV state-space model, 2) generation of the polytopic model; and 3) application of LMI to derive controller and observer. He goes on to describe why literature has extensively studied LMI design, but has not focused much on the second step, in part because the generation and manipulation of the polytopic form was not tractable in many cases. The author then shows how the TP model transformation facilitates this second step and hence reveals new directions, leading to powerful design procedures and the formulation of new questions. The chapters of this book, and the complex dynamical control tasks which they cover, are organized so as to present and analyze the beneficial aspect of the family of approaches (control, design, and optimization). Additionally, the b...
Optimization of mask manufacturing rule check constraint for model based assist feature generation
Shim, Seongbo; Kim, Young-chang; Chun, Yong-jin; Lee, Seong-Woo; Lee, Suk-joo; Choi, Seong-woon; Han, Woo-sung; Chang, Seong-hoon; Yoon, Seok-chan; Kim, Hee-bom; Ki, Won-tai; Woo, Sang-gyun; Cho, Han-gu
2008-11-01
SRAF (sub-resolution assist feature) generation technology has been a popular resolution enhancement technique in photo-lithography past sub-65nm node. It helps to increase the process window, and these are some times called ILT(inverse lithography technology). Also, many studies have been presented on how to determine the best positions of SRAFs, and optimize its size. According to these reports, the generation of SRAF can be formulated as a constrained optimization problem. The constraints are the side lobe suppression and allowable minimum feature size or MRC (mask manufacturing rule check). As we know, bigger SRAF gives better contribution to main feature but susceptible to SRAF side lobe issue. Thus, we finally have no choice but to trade-off the advantages of the ideally optimized mask that contains very complicated SRAF patterns to the layout that has been MRC imposed applied to it. The above dilemma can be resolved by simultaneously using lower dose (high threshold) and cleaning up by smaller MRC. This solution makes the room between threshold (side lobe limitation) and MRC constraint (minimum feature limitation) wider. In order to use smaller MRC restriction without considering the mask writing and inspection issue, it is also appropriate to identify the exact mask writing limitation and find the smart mask constraints that well reflect the mask manufacturability and the e-beam lithography characteristics. In this article, we discuss two main topics on mask optimizations with SRAF. The first topic is on the experimental work to find what behavior of the mask writing ability is in term of several MRC parameters, and we propose more effective MRC constraint for aggressive generation of SRAF. The next topic is on finding the optimum MRC condition in practical case, 3X nm node DRAM contact layer. In fact, it is not easy to encompass the mask writing capability for very complicate real SRAF pattern by using the current MRC constraint based on the only width and
Directory of Open Access Journals (Sweden)
Natalya Pya
2016-02-01
Full Text Available Background: Measurements of tree heights and diameters are essential in forest assessment and modelling. Tree heights are used for estimating timber volume, site index and other important variables related to forest growth and yield, succession and carbon budget models. However, the diameter at breast height (dbh can be more accurately obtained and at lower cost, than total tree height. Hence, generalized height-diameter (h-d models that predict tree height from dbh, age and other covariates are needed. For a more flexible but biologically plausible estimation of covariate effects we use shape constrained generalized additive models as an extension of existing h-d model approaches. We use causal site parameters such as index of aridity to enhance the generality and causality of the models and to enable predictions under projected changeable climatic conditions. Methods: We develop unconstrained generalized additive models (GAM and shape constrained generalized additive models (SCAM for investigating the possible effects of tree-specific parameters such as tree age, relative diameter at breast height, and site-specific parameters such as index of aridity and sum of daily mean temperature during vegetation period, on the h-d relationship of forests in Lower Saxony, Germany. Results: Some of the derived effects, e.g. effects of age, index of aridity and sum of daily mean temperature have significantly non-linear pattern. The need for using SCAM results from the fact that some of the model effects show partially implausible patterns especially at the boundaries of data ranges. The derived model predicts monotonically increasing levels of tree height with increasing age and temperature sum and decreasing aridity and social rank of a tree within a stand. The definition of constraints leads only to marginal or minor decline in the model statistics like AIC. An observed structured spatial trend in tree height is modelled via 2-dimensional surface
LHC constraints on large scalar multiplet models with a $Z_2$ symmetry
Logan, Heather E; Pilkington, Terry
2015-01-01
We study the LHC search constraints on models that extend the Standard Model (SM) with an inert, complex scalar electroweak multiplet, $\\Sigma$, with isospin T=5/2 (sextet) or T=7/2 (octet) and identical hypercharge to the SM Higgs doublet. Imposing a global $Z_2$ symmetry under which $\\Sigma \\to -\\Sigma$, the lightest member of $\\Sigma$ is stable and we require that it be neutral ($\\zeta^{0,r}$) to avoid cosmological constraints from charged relics. Pair production of scalars by electroweak interactions followed by cascade decays to $\\zeta^{0,r}$ through W and Z emission produces signatures similar to those of supersymmetric electroweak gauginos, and we constrain the models by recasting a collection of such searches made with data from the 8 TeV run of the LHC. We find that there is no sensitivity from these searches to the compressed spectrum regime, in which the mass splittings between the lightest and heaviest states in $\\Sigma$ are less than about 20 GeV. In the remaining parameter space, we find signifi...
Indirect detection constraints on s- and t-channel simplified models of dark matter
Carpenter, Linda M.; Colburn, Russell; Goodman, Jessica; Linden, Tim
2016-09-01
Recent Fermi-LAT observations of dwarf spheroidal galaxies in the Milky Way have placed strong limits on the gamma-ray flux from dark matter annihilation. In order to produce the strongest limit on the dark matter annihilation cross section, the observations of each dwarf galaxy have typically been "stacked" in a joint-likelihood analysis, utilizing optical observations to constrain the dark matter density profile in each dwarf. These limits have typically been computed only for singular annihilation final states, such as b b ¯ or τ+τ- . In this paper, we generalize this approach by producing an independent joint-likelihood analysis to set constraints on models where the dark matter particle annihilates to multiple final-state fermions. We interpret these results in the context of the most popular simplified models, including those with s- and t-channel dark matter annihilation through scalar and vector mediators. We present our results as constraints on the minimum dark matter mass and the mediator sector parameters. Additionally, we compare our simplified model results to those of effective field theory contact interactions in the high-mass limit.
Magneto-convective models of red dwarfs: constraints imposed by the lithium abundance
MacDonald, J
2015-01-01
Magnetic fields impede the onset of convection, thereby altering the thermal structure of a convective envelope in a low mass star: this has an effect on the amount of lithium depletion in a magnetized star. In order to quantify this effect, we have applied a magneto-convective model to two low mass stars for which lithium abundances and precise structural parameters are known: YY Gem and CU Cnc. For both stars, we have obtained models which satisfy empirical constraints on the following parameters: R, L, surface magnetic field strength, and Li abundance. In the case of YY Gem, we have obtained a model which satisfies the empirical constraints with an internal magnetic field of several megagauss: such a field strength is within the range of a dynamo where the field energy is in equipartition with rotational energy deep inside the convection zone. However, in the case of CU Cnc, the Li requires an internal magnetic field which is probably too strong for a dynamo origin: we suggest possible alternatives which m...
Energy Technology Data Exchange (ETDEWEB)
Cho, Su Gil; Jang, Jun Yong; Kim, Ji Hoon; Lee, Tae Hee [Hanyang University, Seoul (Korea, Republic of); Lee, Min Uk [Romax Technology Ltd., Seoul (Korea, Republic of); Choi, Jong Su; Hong, Sup [Korea Research Institute of Ships and Ocean Engineering, Daejeon (Korea, Republic of)
2015-04-15
Sequential surrogate model-based global optimization algorithms, such as super-EGO, have been developed to increase the efficiency of commonly used global optimization technique as well as to ensure the accuracy of optimization. However, earlier studies have drawbacks because there are three phases in the optimization loop and empirical parameters. We propose a united sampling criterion to simplify the algorithm and to achieve the global optimum of problems with constraints without any empirical parameters. It is able to select the points located in a feasible region with high model uncertainty as well as the points along the boundary of constraint at the lowest objective value. The mean squared error determines which criterion is more dominant among the infill sampling criterion and boundary sampling criterion. Also, the method guarantees the accuracy of the surrogate model because the sample points are not located within extremely small regions like super-EGO. The performance of the proposed method, such as the solvability of a problem, convergence properties, and efficiency, are validated through nonlinear numerical examples with disconnected feasible regions.
Astrophysical Constraints on the scale of Left-Right Symmetry in Inverse Seesaw Models
Borah, Debasish
2012-01-01
We revisit the recently studied supersymmetric gauged inverse seesaw model \\cite{An:2011uq} to incorporate astrophysical constraints on lightest supersymmetric particle (LSP) lifetime such that LSP constitutes the dark matter of the Universe. The authors in \\cite{An:2011uq} considered light sneutrino LSP that can play the role of inelastic dark matter (iDM) such that desired iDM mass splitting and tiny Majorana masses of neutrinos can have a common origin. Here we point out that due to spontaneous R-parity $(R_p = (-1)^{3(B-L)+2s})$ breaking in such generic supersymmetric gauged inverse seesaw models, LSP can not be perfectly stable but decays to standard model particles after non-renormalizable operators allowed by the gauge symmetry are introduced. We show that strong astrophysical constraints on LSP lifetime makes sneutrino dark matter more natural than standard neutralino dark matter. We also show that long-livedness of sneutrino dark matter constrains the left right symmetry breaking scale $M_R < 10^4...
Wang, Lu; Shen, Jincheng; Thall, Peter F
2014-10-01
In many biomedical studies, identifying effects of covariate interactions on survival is a major goal. Important examples are treatment-subgroup interactions in clinical trials, and gene-gene or gene-environment interactions in genomic studies. A common problem when implementing a variable selection algorithm in such settings is the requirement that the model must satisfy the strong heredity constraint, wherein an interaction may be included in the model only if the interaction's component variables are included as main effects. We propose a modified Lasso method for the Cox regression model that adaptively selects important single covariates and pairwise interactions while enforcing the strong heredity constraint. The proposed method is based on a modified log partial likelihood including two adaptively weighted penalties, one for main effects and one for interactions. A two-dimensional tuning parameter for the penalties is determined by generalized cross-validation. Asymptotic properties are established, including consistency and rate of convergence, and it is shown that the proposed selection procedure has oracle properties, given proper choice of regularization parameters. Simulations illustrate that the proposed method performs reliably across a range of different scenarios.
Institute of Scientific and Technical Information of China (English)
Guangdong TIAN; Hua KE; Xiaowei CHEN
2014-01-01
Facility location allocation (FLA) is one of the important issues in the logistics and transportation fields. In practice, since customer demands, allocations, and even locations of customers and facilities are usually changing, the FLA problem fea-tures uncertainty. To account for this uncertainty, some researchers have addressed the fuzzy profit and cost issues of FLA. However, a decision-maker needs to reach a specific profit, minimizing the cost to target customers. To handle this issue it is essential to propose an effective fuzzy cost-profit tradeoff approach of FLA. Moreover, some regional constraints can greatly influence FLA. By taking a vehicle inspection station as a typical automotive service enterprise example, and combined with the credibility measure of fuzzy set theory, this work presents new fuzzy cost-profit tradeoff FLA models with regional constraints. A hybrid algorithm integrating fuzzy simulation and genetic algorithms (GA) is proposed to solve the proposed models. Some numerical examples are given to illustrate the proposed models and the effectiveness of the proposed algorithm.
Measurement of noise associated with model transformer cores
Energy Technology Data Exchange (ETDEWEB)
Snell, David [Cogent Power Ltd., Development and Market Research, Orb Electrical Steels, Corporation Road, Newport, South Wales NP19 OXT (United Kingdom)], E-mail: Dave.snell@cogent-power.com
2008-10-15
The performance of a transformer core may be considered in terms of power loss and by the noise generated by the core, both of which should be minimised. This paper discusses the setting up of a suitable system for evaluation of noise in a large model transformer core (500 kV A) and issues associated with noise measurement. The equivalent continuous sound pressure level (LAeq) was used as a measure of the A-weighted sound level and measurements were made in the range 16 Hz-25 kHz for various step lap core configurations. The selection of optimum sound insulation materials between core and ground support and for enclosing the transformer is essential for minimisation of background noise. Core clamping pressure must be optimised in order to minimise noise. The use of two laminations per layer instead of one leads to an increase in noise arising from the core. Provided care is taken in building the core, good reproducibility of results can be obtained for analysis.
Testolin, Alberto; De Filippo De Grazia, Michele; Zorzi, Marco
2017-01-01
The recent "deep learning revolution" in artificial neural networks had strong impact and widespread deployment for engineering applications, but the use of deep learning for neurocomputational modeling has been so far limited. In this article we argue that unsupervised deep learning represents an important step forward for improving neurocomputational models of perception and cognition, because it emphasizes the role of generative learning as opposed to discriminative (supervised) learning. As a case study, we present a series of simulations investigating the emergence of neural coding of visual space for sensorimotor transformations. We compare different network architectures commonly used as building blocks for unsupervised deep learning by systematically testing the type of receptive fields and gain modulation developed by the hidden neurons. In particular, we compare Restricted Boltzmann Machines (RBMs), which are stochastic, generative networks with bidirectional connections trained using contrastive divergence, with autoencoders, which are deterministic networks trained using error backpropagation. For both learning architectures we also explore the role of sparse coding, which has been identified as a fundamental principle of neural computation. The unsupervised models are then compared with supervised, feed-forward networks that learn an explicit mapping between different spatial reference frames. Our simulations show that both architectural and learning constraints strongly influenced the emergent coding of visual space in terms of distribution of tuning functions at the level of single neurons. Unsupervised models, and particularly RBMs, were found to more closely adhere to neurophysiological data from single-cell recordings in the primate parietal cortex. These results provide new insights into how basic properties of artificial neural networks might be relevant for modeling neural information processing in biological systems.
Testolin, Alberto; De Filippo De Grazia, Michele; Zorzi, Marco
2017-01-01
The recent “deep learning revolution” in artificial neural networks had strong impact and widespread deployment for engineering applications, but the use of deep learning for neurocomputational modeling has been so far limited. In this article we argue that unsupervised deep learning represents an important step forward for improving neurocomputational models of perception and cognition, because it emphasizes the role of generative learning as opposed to discriminative (supervised) learning. As a case study, we present a series of simulations investigating the emergence of neural coding of visual space for sensorimotor transformations. We compare different network architectures commonly used as building blocks for unsupervised deep learning by systematically testing the type of receptive fields and gain modulation developed by the hidden neurons. In particular, we compare Restricted Boltzmann Machines (RBMs), which are stochastic, generative networks with bidirectional connections trained using contrastive divergence, with autoencoders, which are deterministic networks trained using error backpropagation. For both learning architectures we also explore the role of sparse coding, which has been identified as a fundamental principle of neural computation. The unsupervised models are then compared with supervised, feed-forward networks that learn an explicit mapping between different spatial reference frames. Our simulations show that both architectural and learning constraints strongly influenced the emergent coding of visual space in terms of distribution of tuning functions at the level of single neurons. Unsupervised models, and particularly RBMs, were found to more closely adhere to neurophysiological data from single-cell recordings in the primate parietal cortex. These results provide new insights into how basic properties of artificial neural networks might be relevant for modeling neural information processing in biological systems. PMID:28377709
Thermodynamic analysis of regulation in metabolic networks using constraint-based modeling
Directory of Open Access Journals (Sweden)
Mahadevan Radhakrishnan
2010-05-01
Full Text Available Abstract Background Geobacter sulfurreducens is a member of the Geobacter species, which are capable of oxidation of organic waste coupled to the reduction of heavy metals and electrode with applications in bioremediation and bioenergy generation. While the metabolism of this organism has been studied through the development of a stoichiometry based genome-scale metabolic model, the associated regulatory network has not yet been well studied. In this manuscript, we report on the implementation of a thermodynamics based metabolic flux model for Geobacter sulfurreducens. We use this updated model to identify reactions that are subject to regulatory control in the metabolic network of G. sulfurreducens using thermodynamic variability analysis. Findings As a first step, we have validated the regulatory sites and bottleneck reactions predicted by the thermodynamic flux analysis in E. coli by evaluating the expression ranges of the corresponding genes. We then identified ten reactions in the metabolic network of G. sulfurreducens that are predicted to be candidates for regulation. We then compared the free energy ranges for these reactions with the corresponding gene expression fold changes under conditions of different environmental and genetic perturbations and show that the model predictions of regulation are consistent with data. In addition, we also identify reactions that operate close to equilibrium and show that the experimentally determined exchange coefficient (a measure of reversibility is significant for these reactions. Conclusions Application of the thermodynamic constraints resulted in identification of potential bottleneck reactions not only from the central metabolism but also from the nucleotide and amino acid subsystems, thereby showing the highly coupled nature of the thermodynamic constraints. In addition, thermodynamic variability analysis serves as a valuable tool in estimating the ranges of ΔrG' of every reaction in the model
Development and validation of a tokamak skin effect transformer model
Romero, J. A.; Moret, J.-M.; Coda, S.; Felici, F.; Garrido, I.
2012-02-01
A lumped parameter, state space model for a tokamak transformer including the slow flux penetration in the plasma (skin effect transformer model) is presented. The model does not require detailed or explicit information about plasma profiles or geometry. Instead, this information is lumped in system variables, parameters and inputs. The model has an exact mathematical structure built from energy and flux conservation theorems, predicting the evolution and non-linear interaction of plasma current and internal inductance as functions of the primary coil currents, plasma resistance, non-inductive current drive and the loop voltage at a specific location inside the plasma (equilibrium loop voltage). Loop voltage profile in the plasma is substituted by a three-point discretization, and ordinary differential equations are used to predict the equilibrium loop voltage as a function of the boundary and resistive loop voltages. This provides a model for equilibrium loop voltage evolution, which is reminiscent of the skin effect. The order and parameters of this differential equation are determined empirically using system identification techniques. Fast plasma current modulation experiments with random binary signals have been conducted in the TCV tokamak to generate the required data for the analysis. Plasma current was modulated under ohmic conditions between 200 and 300 kA with 30 ms rise time, several times faster than its time constant L/R ≈ 200 ms. A second-order linear differential equation for equilibrium loop voltage is sufficient to describe the plasma current and internal inductance modulation with 70% and 38% fit parameters, respectively. The model explains the most salient features of the plasma current transients, such as the inverse correlation between plasma current ramp rates and internal inductance changes, without requiring detailed or explicit information about resistivity profiles. This proves that a lumped parameter modelling approach can be used to
High frequency modeling of power transformers. Stresses and diagnostics
Energy Technology Data Exchange (ETDEWEB)
Bjerkan, Eilert
2005-05-15
In this thesis a reliable, versatile and rigorous method for high frequency power transformer modeling is searched and established. The purpose is to apply this model to sensitivity analysis of FRA (Frequency Response Analysis) which is a quite new diagnostic method for assessing the mechanical integrity of power transformer windings on-site. The method should be versatile in terms of being able to estimate internal and external over voltages and resonances. Another important aspect is that the method chosen is suitable for real transformer geometries. In order to verify the suitability of the model for real transformers, a specific test-object is used. This is a 20MVA transformer, and details are given in chapter 1.4. The high frequency power transformer model is established from geometrical and constructional information from the manufacturer, together with available material characteristics. All circuit parameters in the lumped circuit representation are calculated based on these data. No empirical modifications need to be performed. Comparison shows capability of reasonable accuracy in the range from 10 khz to 1 MHz utilizing a disc-to-disc representation. A compromise between accuracy of model due to discretization and complexity of the model in a turn-to-turn representation is inevitable. The importance of the iron core is emphasized through a comparison of representations with/without the core included. Frequency-dependent phenomena are accurately represented using an isotropic equivalent for windings and core, even with a coarse mesh for the FEM-model. This is achieved through a frequency-dependent complex permeability representation of the materials. This permeability is deduced from an analytical solution of the frequency-dependent magnetic field inside the conductors and the core. The importance of dielectric losses in a transformer model is also assessed. Since published data on the high frequency properties of press board are limited, some initial
Model Transformation for Model Driven Development of Semantic Web Enabled Multi-Agent Systems
Kardas, G.; Göknil, Arda; Dikenelli, O.; Topaloglu, N.Y.; Weyns, D.; Holvoet, T.
2007-01-01
Model Driven Development (MDD) provides an infrastructure that simplifies Multi-agent System (MAS) development by increasing the abstraction level. In addition to defining models, transformation process for those models is also crucial in MDD. On the other hand, MAS modeling should also take care of
Model Transformation for Model Driven Development of Semantic Web Enabled Multi-Agent Systems
Kardas, G.; Göknil, A.; Dikenelli, O.; Topaloglu, N.Y.
2007-01-01
Model Driven Development (MDD) provides an infrastructure that simplifies Multi-agent System (MAS) development by increasing the abstraction level. In addition to defining models, transformation process for those models is also crucial in MDD. On the other hand, MAS modeling should also take care of
Local Model Checking of Weighted CTL with Upper-Bound Constraints
DEFF Research Database (Denmark)
Jensen, Jonas Finnemann; Larsen, Kim Guldstrand; Srba, Jiri
2013-01-01
graphs. We implement all algorithms in a publicly available tool prototype and evaluate them on several experiments. The principal conclusion is that our local algorithm is the most efficient one with an order of magnitude improvement for model checking problems with a high number of “witnesses”.......We present a symbolic extension of dependency graphs by Liu and Smolka in order to model-check weighted Kripke structures against the logic CTL with upper-bound weight constraints. Our extension introduces a new type of edges into dependency graphs and lifts the computation of fixed-points from...... boolean domain to nonnegative integers in order to cope with the weights. We present both global and local algorithms for the fixed-point computation on symbolic dependency graphs and argue for the advantages of our approach compared to the direct encoding of the model checking problem into dependency...
A novel interconnect-optimal repeater insertion model with target delay constraint in 65 nm CMOS
Institute of Scientific and Technical Information of China (English)
Zhu Zhang-Ming; Qian Li-Bo; Yang Yin-Tang
2009-01-01
Repeater optimization is the key for SOC (System on Chip) interconnect delay design. This paper proposes a novel optimal model for minimizing power and area overhead of repeaters while meeting the target performance of on-chip interconnect lines. It also presents Lagrangian function to find the number of repeaters and their sizes required for minimizing area and power overhead with target delay constraint. Based on the 65 nanometre CMOS technology, the computed results of the intermediate and global lines show that the proposed model can significantly reduce area and power of interconnected lines, and the better performance will be achieved with the longer line. The results compared with the reference paper demonstrate the validity of this model. It can be integrated into repeater design methodology and CAD (computer aided design) tool for interconnect planning in nanometre SOC.
Collide and Conquer: Constraints on Simplified Dark Matter Models using Mono-X Collider Searches
Brennan, A J; Gramling, J; Jacques, T D
2016-01-01
The use of simplified models as a tool for interpreting dark matter collider searches has become increasingly prevalent, and while early Run II results are beginning to appear, we look to see what further information can be extracted from the Run I dataset. We consider three `standard' simplified models that couple quarks to fermionic singlet dark matter: an $s$-channel vector mediator with vector or axial-vector couplings, and a $t$-channel scalar mediator. Upper limits on the couplings are calculated and compared across three alternate channels, namely mono-jet, mono-$Z$ (leptonic) and mono-$W/Z$ (hadronic). The strongest limits are observed in the mono-jet channel, however the computational simplicity and absence of significant $t$-channel model width effects in the mono-boson channels make these a straightforward and competitive alternative. We also include a comparison with relic density and direct detection constraints.
More on cosmological constraints on spontaneous R-symmetry breaking models
Energy Technology Data Exchange (ETDEWEB)
Hamada, Yuta; Kobayashi, Tatsuo [Kyoto Univ. (Japan). Dept. of Physics; Kamada, Kohei [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Ecole Polytechnique Federale de Lausanne (Switzerland). Inst. de Theorie des Phenomenes Physiques; Ookouchi, Yutaka [Kyushu Univ., Fukuoka (Japan). Faculty of Arts and Science
2013-10-15
We study the spontaneous R-symmetry breaking model and investigate the cosmological constraints on this model due to the pseudo Nambu-Goldstone boson, R-axion. We consider the R-axion which has relatively heavy mass in order to complement our previous work. In this regime, model parameters, R-axions mass and R-symmetry breaking scale, are constrained by Big Bang Nucleosynthesis and overproduction of the gravitino produced from R-axion decay and thermal plasma. We find that the allowed parameter space is very small for high reheating temperature. For low reheating temperature, the U(1){sub R} breaking scale f{sub a} is constrained as f{sub a}<10{sup 12-14} GeV regardless of the value of R-axion mass.
DEFF Research Database (Denmark)
Sanchez, Benjamin J.; Zhang, Xi-Cheng; Nilsson, Avlant
2017-01-01
Genome-scale metabolic models (GEMs) are widely used to calculate metabolic phenotypes. They rely on defining a set of constraints, the most common of which is that the production of metabolites and/or growth are limited by the carbon source uptake rate. However, enzyme abundances and kinetics......, which act as limitations on metabolic fluxes, are not taken into account. Here, we present GECKO, a method that enhances a GEM to account for enzymes as part of reactions, thereby ensuring that each metabolic flux does not exceed its maximum capacity, equal to the product of the enzyme's abundance...... with stress, or overexpressing a specific pathway. GECKO also allows to directly integrate quantitative proteomics data; by doing so, we significantly reduced flux variability of the model, in over 60% of metabolic reactions. Additionally, the model gives insight into the distribution of enzyme usage between...
More on cosmological constraints on spontaneous R-symmetry breaking models
Hamada, Yuta; Kobayashi, Tatsuo; Ookouchi, Yutaka
2014-01-01
We study the spontaneous R-symmetry breaking model and investigate the cosmological constraints on this model due to the pseudo Nambu-Goldstone boson, R-axion. We consider the R-axion which has relatively heavy mass in order to complement our previous work. In this regime, model parameters, R-axions mass and R-symmetry breaking scale, are constrained by Big Bang Nucleosynthesis and overproduction of the gravitino produced from R-axion decay and thermal plasma. We find that the allowed parameter space is very small for high reheating temperature. For low reheating temperature, the $U(1)_R$ breaking scale $f_a$ is constrained as $f_a<10^{12-14}\\GeV$ regardless of the value of R-axion mass.
More on cosmological constraints on spontaneous R-symmetry breaking models
Energy Technology Data Exchange (ETDEWEB)
Hamada, Yuta; Kobayashi, Tatsuo [Department of Physics, Kyoto University, Kyoto, 606-8502 (Japan); Kamada, Kohei [Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, Hamburg, D-22607 (Germany); Ookouchi, Yutaka, E-mail: hamada@gauge.scphys.kyoto-u.ac.jp, E-mail: kohei.kamada@epfl.ch, E-mail: kobayash@gauge.scphys.kyoto-u.ac.jp, E-mail: yutaka.ookouchi@artsci.kyushu-u.ac.jp [Faculty of Arts and Science, Kyushu University, Fukuoka, 819–0395 (Japan)
2014-01-01
We study the spontaneous R-symmetry breaking model and investigate the cosmological constraints on this model due to the pseudo Nambu-Goldstone boson, R-axion. We consider the R-axion which has relatively heavy mass in order to complement our previous work. In this regime, model parameters, R-axions mass and R-symmetry breaking scale, are constrained by Big Bang Nucleosynthesis and overproduction of the gravitino produced from R-axion decay and thermal plasma. We find that the allowed parameter space is very small for high reheating temperature. For low reheating temperature, the U(1){sub R} breaking scale f{sub a} is constrained as f{sub a} < 10{sup 12−14} GeV regardless of the value of R-axion mass.
A new model to predict weak-lensing peak counts II. Parameter constraint strategies
Lin, Chieh-An
2015-01-01
Peak counts have been shown to be an excellent tool to extract the non-Gaussian part of the weak lensing signal. Recently, we developped a fast stochastic forward model to predict weak-lensing peak counts. Our model is able to reconstruct the underlying distribution of observables for analyses. In this work, we explore and compare various strategies for constraining parameter using our model, focusing on the matter density $\\Omega_\\mathrm{m}$ and the density fluctuation amplitude $\\sigma_8$. First, we examine the impact from the cosmological dependency of covariances (CDC). Second, we perform the analysis with the copula likelihood, a technique which makes a weaker assumption compared to the Gaussian likelihood. Third, direct, non-analytic parameter estimations are applied using the full information of the distribution. Fourth, we obtain constraints with approximate Bayesian computation (ABC), an efficient, robust, and likelihood-free algorithm based on accept-reject sampling. We find that neglecting the CDC ...
Tevatron constraint on the Kaluza-Klein gluon of the Bulk Randall-Sundrum model
Guchait, M; Sridhar, K
2007-01-01
The Bulk Randall-Sundrum model, where all Standard Model particles except the Higgs are free to propagate in the bulk, predicts the existence of Kaluza-Klein (KK) modes of the gluon with a large branching into top-antitop pairs. We study the production of the lowest KK gluon mode at the Tevatron energy and use the data on the top cross-section from the Run II of Tevatron to put a bound on the mass of the KK gluon. The resulting bound of 800 GeV, while being much smaller than the constraints obtained on the KK gluon mass from flavour-changing neutral currents, is the first, direct collider bound which is independent of the specificities of the model.
Active Shape Models Using Scale Invariant Feature Transform
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
A new active shape models (ASMs) was presented, which is driven by scale invariant feature transform (SIFT) local descriptor instead of normalizing first order derivative profiles in the original formulation, to segment lung fields from chest radiographs. The modified SIFT local descriptor, more distinctive than the general intensity and gradient features, is used to characterize the image features in the vicinity of each pixel at each resolution level during the segmentation optimization procedure. Experimental results show that the proposed method is more robust and accurate than the original ASMs in terms of an average overlap percentage and average contour distance in segmenting the lung fields from an available public database.
ASYMPTOTICS OF MEAN TRANSFORMATION ESTIMATORS WITH ERRORS IN VARIABLES MODEL
Institute of Scientific and Technical Information of China (English)
CUI Hengjian
2005-01-01
This paper addresses estimation and its asymptotics of mean transformation θ = E[h(X)] of a random variable X based on n iid. Observations from errors-in-variables model Y = X + v, where v is a measurement error with a known distribution and h(.) is a known smooth function. The asymptotics of deconvolution kernel estimator for ordinary smooth error distribution and expectation extrapolation estimator are given for normal error distribution respectively. Under some mild regularity conditions, the consistency and asymptotically normality are obtained for both type of estimators. Simulations show they have good performance.
Text-Independent Speaker Identification Using the Histogram Transform Model
DEFF Research Database (Denmark)
Ma, Zhanyu; Yu, Hong; Tan, Zheng-Hua;
2017-01-01
In this paper, we propose a novel probabilistic method for the task of text-independent speaker identification (SI). In order to capture the dynamic information during SI, we design a super-MFCCs features by cascading three neighboring Mel-frequency Cepstral coefficients (MFCCs) frames together....... These super-MFCC vectors are utilized for probabilistic model training such that the speaker’s characteristics can be sufficiently captured. The probability density function (PDF) of the aforementioned super-MFCCs features is estimated by the recently proposed histogram transform (HT) method. To recedes...
Coupling capacitor voltage transformer: A model for electromagnetic transient studies
Energy Technology Data Exchange (ETDEWEB)
Fernandes, D.; Neves, W.L.A. [Department of Electrical Engineering, Federal University of Campina Grande, Av. Aprigio Veloso, 882 Bodocongo, 58.109-970 Campina Grande, PB (Brazil); Vasconcelos, J.C.A. [Companhia Hidro Eletrica do Sao Francisco, Rua Delmiro Gouveia, 333 Bongi, 50.761-901 Recife, PE (Brazil)
2007-02-15
In this work, an accurate coupling capacitor voltage transformer (CCVT) model for electromagnetic transient studies is presented. The model takes into account linear and nonlinear elements. A support routine was developed to compute the linear 230kV CCVT parameters (resistances, inductances and capacitances) from frequency response data. The magnetic core and surge arrester nonlinear characteristics were estimated from laboratory measurements as well. The model is used in connection with the electromagnetic transients program (EMTP) to predict the CCVT performance when it is submitted to transient overvoltages, as are the cases of voltages due to the ferroresonance phenomenon and circuit breaker switching. The difference between simulated and measured results is fairly small. Simulations had shown that transient overvoltages produced inside the CCVT, when a short circuit is cleared at the CCVT secondary side, are effectively damped out by the ferroresonance suppression circuit and the protection circuit. (author)
Generating WS-SecurityPolicy documents via security model transformation
DEFF Research Database (Denmark)
Jensen, Meiko
2009-01-01
When SOA-based business processes are to be enhanced with security properties, the model-driven business process development approach enables an easier and more reliable security definition compared to manually crafting the security realizations afterwards. In this paper, we outline an appropriat...... security model definition and transformation approach, targeting the WS-SecurityPolicy and WS-BPEL specifications, in order to enable a Web-Service-based secure business process development.......When SOA-based business processes are to be enhanced with security properties, the model-driven business process development approach enables an easier and more reliable security definition compared to manually crafting the security realizations afterwards. In this paper, we outline an appropriate...
Diagnostic and Prognostic Models for Generator Step-Up Transformers
Energy Technology Data Exchange (ETDEWEB)
Vivek Agarwal; Nancy J. Lybeck; Binh T. Pham
2014-09-01
In 2014, the online monitoring (OLM) of active components project under the Light Water Reactor Sustainability program at Idaho National Laboratory (INL) focused on diagnostic and prognostic capabilities for generator step-up transformers. INL worked with subject matter experts from the Electric Power Research Institute (EPRI) to augment and revise the GSU fault signatures previously implemented in the Electric Power Research Institute’s (EPRI’s) Fleet-Wide Prognostic and Health Management (FW-PHM) Suite software. Two prognostic models were identified and implemented for GSUs in the FW-PHM Suite software. INL and EPRI demonstrated the use of prognostic capabilities for GSUs. The complete set of fault signatures developed for GSUs in the Asset Fault Signature Database of the FW-PHM Suite for GSUs is presented in this report. Two prognostic models are described for paper insulation: the Chendong model for degree of polymerization, and an IEEE model that uses a loading profile to calculates life consumption based on hot spot winding temperatures. Both models are life consumption models, which are examples of type II prognostic models. Use of the models in the FW-PHM Suite was successfully demonstrated at the 2014 August Utility Working Group Meeting, Idaho Falls, Idaho, to representatives from different utilities, EPRI, and the Halden Research Project.
Transforming Graphical System Models to Graphical Attack Models
DEFF Research Database (Denmark)
Ivanova, Marieta Georgieva; Probst, Christian W.; Hansen, Rene Rydhof;
2016-01-01
Manually identifying possible attacks on an organisation is a complex undertaking; many different factors must be considered, and the resulting attack scenarios can be complex and hard to maintain as the organisation changes. System models provide a systematic representation of organisations that...
Transforming graphical system models to graphical attack models
Ivanova, Marieta Georgieva; Probst, Christian W.; Hansen, René Rydhof; Kammüller, Florian; Mauw, S.; Kordy, B.
2015-01-01
Manually identifying possible attacks on an organisation is a complex undertaking; many different factors must be considered, and the resulting attack scenarios can be complex and hard to maintain as the organisation changes. System models provide a systematic representation of organisations that he
Indirect Detection Constraints on s and t Channel Simplified Models of Dark Matter
Carpenter, Linda M; Goodman, Jessica; Linden, Tim
2016-01-01
Recent Fermi-LAT observations of dwarf spheroidal galaxies in the Milky Way have placed strong limits on the gamma-ray flux from dark matter annihilation. In order to produce the strongest limit on the dark matter annihilation cross-section, the observations of each dwarf galaxy have typically been "stacked" in a joint-likelihood analysis, utilizing optical observations to constrain the dark matter density profile in each dwarf. These limits have typically been computed only for singular annihilation final states, such as $b\\bar{b}$ or $\\tau^+\\tau^-$. In this paper, we generalize this approach by producing an independent joint-likelihood analysis to set constraints on models where the dark matter particle annihilates to multiple final state fermions. We interpret these results in the context of the most popular simplified models, including those with s- and t-channel dark matter annihilation through scalar and vector mediators. We present our results as constraints on the minimum dark matter mass and the medi...
Flavor constraints on the Two Higgs Doublet Models of $Z_2$ symmetric and aligned types
Enomoto, Tetsuya
2015-01-01
We give a comprehensive study from flavor observables of pion, kaon, D_(s), and B_(s) mesons for limiting the Two Higgs Doublet Models (2HDMs) with natural flavor conservation, namely, Z_2 symmetric and aligned type of models. With use of the updated studies and analyses of B -> tau nu, D -> mu nu, D_s -> tau nu, D_s -> mu nu, K -> mu nu, Pi -> mu nu, B^0_s -> mu^+ mu^-, B^0_d -> mu^+ mu^-, tau -> K nu, tau -> Pi nu, B -> X_s gamma, K-K bar mixing, B^0_d-B^0_d bar mixing, and B^0_s-B^0_s bar mixing, we obtain constraints on the parameters in the 2HDMs. To calculate the constraints, we pay attention to a determination of CKM matrix elements and re-fit them to experimental data so that new contributions from additional Higgs bosons do not affect the determination. In addition, we discuss excesses of observables in the muon anomalous magnetic moment and the semi-tauonic B meson decays in the context of the 2HDM.
Beyond the model democracy: observational constraints indicate risk of drying in the Amazon basin
Shiogama, Hideo; Emori, Seita; Hanasaki, Naota; Abe, Manabu; Masutomi, Yuji; Takahashi, Kiyoshi; Nozawa, Toru
2013-04-01
Climate warming due to human activities will be accompanied by hydrological cycle changes. Economies, societies and ecosystems in South America (SA) are vulnerable to such water resource changes. Hence, water resource impact assessments for SA, and corresponding adaptation and mitigation policies, have attracted increased attention. However, substantial uncertainties remain in the current water resource assessments that are based on multiple coupled Atmosphere Ocean General Circulation models. This uncertainty varies from significant wetting to catastrophic drying. By applying a statistical method, we characterised the uncertainty and identified global-scale metrics for measuring the reliability of water resource assessments in SA. Here we show that, whereas the ensemble mean assessment suggested wetting across most of SA, the observational constraints indicate a higher probability of drying in the Amazon basin. Naive over-reliance on the consensus of models can lead to inappropriate decision making. Reference: Shiogama, H. et al. Observational constraints indicate risk of drying in the Amazon basin. Nature Communications 2:253 doi: 10.1038/ncomms1252 (2011).
Massari, Andrea; Essig, Rouven; Albert, Andrea; Bloom, Elliott; Gomez-Vargas, German A
2015-01-01
We set conservative, robust constraints on the annihilation and decay of dark matter into various Standard Model final states under various assumptions about the distribution of the dark matter in the Milky Way halo. We use the inclusive photon spectrum observed by the Fermi Gamma-ray Space Telescope through its main instrument, the Large-Area Telescope (LAT). We use simulated data to first find the "optimal" regions of interest in the gamma-ray sky, where the expected dark matter signal is largest compared with the expected astrophysical foregrounds. We then require the predicted dark matter signal to be less than the observed photon counts in the a priori optimal regions. This yields a very conservative constraint as we do not attempt to model or subtract astrophysical foregrounds. The resulting limits are competitive with other existing limits, and, for some final states with cuspy dark-matter distributions in the Galactic Center region, disfavor the typical cross section required during freeze-out for a w...
Massari, Andrea; Izaguirre, Eder; Essig, Rouven; Albert, Andrea; Bloom, Elliott; Gómez-Vargas, Germán Arturo
2015-04-01
We set conservative, robust constraints on the annihilation and decay of dark matter into various Standard Model final states under various assumptions about the distribution of the dark matter in the Milky Way halo. We use the inclusive photon spectrum observed by the Fermi Gamma-ray Space Telescope through its main instrument, the Large Area Telescope. We use simulated data to first find the "optimal" regions of interest in the γ -ray sky, where the expected dark matter signal is largest compared with the expected astrophysical foregrounds. We then require the predicted dark matter signal to be less than the observed photon counts in the a priori optimal regions. This yields a very conservative constraint as we do not attempt to model or subtract astrophysical foregrounds. The resulting limits are competitive with other existing limits and, for some final states with cuspy dark-matter distributions in the Galactic Center region, disfavor the typical cross section required during freeze-out for a weakly interacting massive particle to obtain the observed relic abundance.
The strongest experimental constraints on SU(5)xU(1) supergravity models
López, J; Park, G; Zichichi, A
1994-01-01
We consider a class of well motivated string-inspired flipped $SU(5)$ supergravity models which include four supersymmetry breaking scenarios: no-scale, strict no-scale, dilaton, and special dilaton, such that only three parameters are needed to describe all new phenomena $(m_t,\\tan\\beta,m_{\\tilde g})$. We show that the LEP precise measurements of the electroweak parameters in the form of the $\\epsilon_1$ variable, and the CLEOII allowed range for $\\bsg$ are at present the most important experimental constraints on this class of models. For $m_t\\gsim155\\,(165)\\GeV$, the $\\epsilon_1$ constraint (at 90(95)\\%CL) requires the presence of light charginos ($m_{\\chi^\\pm_1}\\lsim50-100\\GeV$ depending on $m_t$). Since all sparticle masses are proportional to $m_{\\tilde g}$, $m_{\\chi^\\pm_1}\\lsim100\\GeV$ implies: $m_{\\chi^0_1}\\lsim55\\GeV$, $m_{\\chi^0_2}\\lsim100\\GeV$, $m_{\\tilde g}\\lsim360\\GeV$, $m_{\\tilde q}\\lsim350\\,(365)\\GeV$, $m_{\\tilde e_R}\\lsim80\\,(125)\\GeV$, $m_{\\tilde e_L}\\lsim120\\,(155)\\GeV$, and $m_{\\tilde\
Energy Technology Data Exchange (ETDEWEB)
Doligez, B.; Eschard, R. [Institut Francais du Petrole, Rueil Malmaison (France); Geffroy, F. [Centre de Geostatistique, Fontainebleau (France)] [and others
1997-08-01
The classical approach to construct reservoir models is to start with a fine scale geological model which is informed with petrophysical properties. Then scaling-up techniques allow to obtain a reservoir model which is compatible with the fluid flow simulators. Geostatistical modelling techniques are widely used to build the geological models before scaling-up. These methods provide equiprobable images of the area under investigation, which honor the well data, and which variability is the same than the variability computed from the data. At an appraisal phase, when few data are available, or when the wells are insufficient to describe all the heterogeneities and the behavior of the field, additional constraints are needed to obtain a more realistic geological model. For example, seismic data or stratigraphic models can provide average reservoir information with an excellent areal coverage, but with a poor vertical resolution. New advances in modelisation techniques allow now to integrate this type of additional external information in order to constrain the simulations. In particular, 2D or 3D seismic derived information grids, or sand-shale ratios maps coming from stratigraphic models can be used as external drifts to compute the geological image of the reservoir at the fine scale. Examples are presented to illustrate the use of these new tools, their impact on the final reservoir model, and their sensitivity to some key parameters.
2008-06-01
mentoring me as well as his generous loan of computing equipment. Tim Grove has been a constant, positive presence throughout my graduate matriculation . I...for finding things out. I am thankful that he "dragged" me on field trips and encouraged my love of mathematics as well as art. My mother, Mickey, is
Constraint-Based Routing Models for the Transport of Radioactive Materials
Energy Technology Data Exchange (ETDEWEB)
Peterson, Steven K [ORNL
2015-01-01
The Department of Energy (DOE) has a historic programmatic interest in the safe and secure routing, tracking, and transportation risk analysis of radiological materials in the United States. In order to address these program goals, DOE has funded the development of several tools and related systems designed to provide insight to planners and other professionals handling radioactive materials shipments. These systems include the WebTRAGIS (Transportation Routing Analysis Geographic Information System) platform. WebTRAGIS is a browser-based routing application developed at Oak Ridge National Laboratory (ORNL) focused primarily on the safe transport of spent nuclear fuel from US nuclear reactors via railway, highway, or waterway. It is also used for the transport planning of low-level radiological waste to depositories such as the Waste Isolation Pilot Plant (WIPP) facility. One particular feature of WebTRAGIS is its coupling with high-resolution population data from ORNL s LandScan project. This allows users to obtain highly accurate population count and density information for use in route planning and risk analysis. To perform the routing and risk analysis WebTRAGIS incorporates a basic routing model methodology, with the additional application of various constraints designed to mimic US Department of Transportation (DOT), DOE, and Nuclear Regulatory Commission (NRC) regulations. Aside from the routing models available in WebTRAGIS, the system relies on detailed or specialized modal networks for the route solutions. These include a highly detailed network model of the US railroad system, the inland and coastal waterways, and a specialized highway network that focuses on the US interstate system and the designated hazardous materials and Highway Route Controlled Quantity (HRCQ) -designated roadways. The route constraints in WebTRAGIS rely upon a series of attributes assigned to the various components of the different modal networks. Routes are determined via a
Explanation Constraint Programming for Model-based Diagnosis of Engineered Systems
Narasimhan, Sriram; Brownston, Lee; Burrows, Daniel
2004-01-01
We can expect to see an increase in the deployment of unmanned air and land vehicles for autonomous exploration of space. In order to maintain autonomous control of such systems, it is essential to track the current state of the system. When the system includes safety-critical components, failures or faults in the system must be diagnosed as quickly as possible, and their effects compensated for so that control and safety are maintained under a variety of fault conditions. The Livingstone fault diagnosis and recovery kernel and its temporal extension L2 are examples of model-based reasoning engines for health management. Livingstone has been shown to be effective, it is in demand, and it is being further developed. It was part of the successful Remote Agent demonstration on Deep Space One in 1999. It has been and is being utilized by several projects involving groups from various NASA centers, including the In Situ Propellant Production (ISPP) simulation at Kennedy Space Center, the X-34 and X-37 experimental reusable launch vehicle missions, Techsat-21, and advanced life support projects. Model-based and consistency-based diagnostic systems like Livingstone work only with discrete and finite domain models. When quantitative and continuous behaviors are involved, these are abstracted to discrete form using some mapping. This mapping from the quantitative domain to the qualitative domain is sometimes very involved and requires the design of highly sophisticated and complex monitors. We propose a diagnostic methodology that deals directly with quantitative models and behaviors, thereby mitigating the need for these sophisticated mappings. Our work brings together ideas from model-based diagnosis systems like Livingstone and concurrent constraint programming concepts. The system uses explanations derived from the propagation of quantitative constraints to generate conflicts. Fast conflict generation algorithms are used to generate and maintain multiple candidates
Institute of Scientific and Technical Information of China (English)
Nan Liang; Pu-Xun Wua; Zong-Hong Zhu
2011-01-01
We constrain the Cardassian expansion models from the latest observations,including the updated Gamma-ray bursts (GRBs),which are calibrated using a cosmology independent method from the Union2 compilation of type Ia supernovae (SNe Ia).By combining the GRB data with the joint observations from the Union2SNe Ia set,along with the results from the Cosmic Microwave Background radiation observation from the seven-year Wilkinson Microwave Anisotropy Probe and the baryonic acoustic oscillation observation galaxy sample from the spectroscopic Sloan Digital Sky Survey Data Release,we find significant constraints on the model parameters of the original Cardassian model ΩM0=n 282+0.015-0.014,n=0.03+0.05-0.05;and n = -0.16+0.25-3.26,β=-0.76+0.34-0.58 of the modified polytropic Cardassian model,which are consistent with the ACDM model in a l-σ confidence region.From the reconstruction of the deceleration parameter q(z) in Cardassian models,we obtain the transition redshift ZT = 0.73 ± 0.04 for the original Cardassian model and ZT = 0.68 ± 0.04 for the modified polytropic Cardassian model.
On Testing Constraint Programs
Lazaar, Nadjib; Yahia, Lebbah
2010-01-01
The success of several constraint-based modeling languages such as OPL, ZINC, or COMET, appeals for better software engineering practices, particularly in the testing phase. This paper introduces a testing framework enabling automated test case generation for constraint programming. We propose a general framework of constraint program development which supposes that a first declarative and simple constraint model is available from the problem specifications analysis. Then, this model is refined using classical techniques such as constraint reformulation, surrogate and global constraint addition, or symmetry-breaking to form an improved constraint model that must be thoroughly tested before being used to address real-sized problems. We think that most of the faults are introduced in this refinement step and propose a process which takes the first declarative model as an oracle for detecting non-conformities. We derive practical test purposes from this process to generate automatically test data that exhibit no...
Directory of Open Access Journals (Sweden)
Yufeng Zhuang
2015-01-01
Full Text Available This paper presents a unified singularity modeling and reconfiguration analysis of variable topologies of a class of metamorphic parallel mechanisms with parallel constraint screws. The new parallel mechanisms consist of three reconfigurable rTPS limbs that have two working phases stemming from the reconfigurable Hooke (rT joint. While one phase has full mobility, the other supplies a constraint force to the platform. Based on these, the platform constraint screw systems show that the new metamorphic parallel mechanisms have four topologies by altering the limb phases with mobility change among 1R2T (one rotation with two translations, 2R2T, and 3R2T and mobility 6. Geometric conditions of the mechanism design are investigated with some special topologies illustrated considering the limb arrangement. Following this and the actuation scheme analysis, a unified Jacobian matrix is formed using screw theory to include the change between geometric constraints and actuation constraints in the topology reconfiguration. Various singular configurations are identified by analyzing screw dependency in the Jacobian matrix. The work in this paper provides basis for singularity-free workspace analysis and optimal design of the class of metamorphic parallel mechanisms with parallel constraint screws which shows simple geometric constraints with potential simple kinematics and dynamics properties.
Observational Constraints on Purely Kinetic/c-Essence Dark Energy Models
Institute of Scientific and Technical Information of China (English)
YANG Rong-Jia; GAO Xiang-Ting
2009-01-01
We consider constraints on purely kinetic k-essence models from the latest observational data (including 182 gold SNIa data,the shift parameter,and the acoustic scale).We find the best-fit values of the parameters are Ωm = 0.37 ±0.01 and κo = 0.064 ± 0.013 at 68.3% confidence level.The phase transition from deceleration to acceleration is found to occur at redshift zq=0～0.48-0.52 in 68.3% confidence level limits.By applying modelcomparison statistics (F-test,AICc,and BIC),we find that the purely kinetic k-essence scenario is favored over the A CDM model by the combined data.These results are also confirmed by combined data 307 SNIa + R + la.
Directory of Open Access Journals (Sweden)
Etienne Thoret
2016-06-01
Full Text Available In this paper, a flexible control strategy for a synthesis model dedicated to nonlinear friction phenomena is proposed. This model enables to synthesize different types of sound sources, such as creaky doors, singing glasses, squeaking wet plates or bowed strings. Based on the perceptual stance that a sound is perceived as the result of an action on an object we propose a genuine source/filter synthesis approach that enables to elude physical constraints induced by the coupling between the interacting objects. This approach makes it possible to independently control and freely combine the action and the object. Different implementations and applications related to computer animation, gesture learning for rehabilitation and expert gestures are presented at the end of this paper.
Directory of Open Access Journals (Sweden)
Jadwiga Zaród
2011-01-01
Full Text Available The farms of Western Pomerania province possess a large surplus of manpower. The dynamic optimization models with random constraints served the investigation of the possibilities of implementation of the unused man-hours. Those models regarded four successive years 2003-2006. The solution proceeded in two steps. The first step let us construct the assumption of the surplus or the deficiency of production factors. In the next step additional variables regarding the lease of arable grounds were introduced while the unused man-hours were implemented with various probability. The optimal solutions indicated the area of particular crops, the quantity of livestock and the farm income dependent on the use of the existing employment. This study aims at the presentation of the possibility of implementation of unused man-hours in farms dealing solely with the crop production and also the production of crop and livestock.