Investigating correlation between legal and physical property: possibilities and constraints

Science.gov (United States)

Dimopoulou, E.; Kitsakis, D.; Tsiliakou, E.

2015-06-01

Contemporary urban environment is characterized by complexity and mixed use of space, in which overlapping land parcels and different RRRs (Rights, Restrictions and Responsibilities) are frequent phenomena. Internationally, real property legislation either focuses on surface property or has introduced individual 3D real property units. The former approach merely accommodates issues related to subdivision, expropriation and transactions on part of the real property above or below surface, while the latter provides for defining and registering 3D real property units. National laws require two-dimensional real property descriptions and only a limited number of jurisdictions provide for threedimensional data presentation and recording. International awareness on 3D Cadastre may be apparent through the proposals for transition of existing cadastral systems to 3D along with legal amendments improving national 3D Cadastre legislation. Concurrently the use of appropriate data sources and the correct depiction of 3D property units' boundaries and spatial relationships need to be addressed. Spatial relations and constraints amongst real world objects could be modeled geometrically and topologically utilizing numerous modeling tools, e.g. CityGML, BIM and further sophisticated 3D software or by adapting international standards, e.g. LADM. A direct correlation between legal and physical property should be based on consistent geometry between physical and legal space, improving the accuracy that legal spaces' volumes or locations are defined. To address these issues, this paper investigates correlation possibilities and constraints between legal and physical space of typical 3D property cases. These cases comprise buildings or their interior spaces with mixed use, as well as complex structures described by explicit facade patterns, generated by procedural or by BIM ready 3D models. The 3D models presented are evaluated, regarding compliancy to physical or legal reality.

An integrated model to measure service management and physical constraints' effect on food consumption in assisted-living facilities.

Science.gov (United States)

Huang, Hui-Chun; Shanklin, Carol W

2008-05-01

The United States is experiencing remarkable growth in the elderly population, which provides both opportunities and challenges for assisted-living facilities. The objective of this study was to explore how service management influences residents' actual food consumption in assisted-living facilities. Physical factors influencing residents' service evaluation and food consumption also were investigated. A total of 394 questionnaires were distributed to assisted-living residents in seven randomly selected facilities. The questionnaire was developed based on an in-depth literature review and pilot study. Residents' perceived quality evaluations, satisfaction, and physical constraints were measured. Residents' actual food consumption was measured using a plate waste technique. A total of 118 residents in five facilities completed both questionnaires and food consumption assessments. Descriptive, multivariate analyses and structural equation modeling techniques were employed. Service management, including food and service quality and customer satisfaction, was found to significantly influence residents' food consumption. Physical constraints associated with aging, including a decline in health status, chewing problems, sensory loss, and functional disability, also significantly influenced residents' food consumption. A significant relationship was found between physical constraints and customer satisfaction. Foodservice that provides good food and service quality increases customer satisfaction and affects residents' actual food consumption. Physical constraints also influence residents' food consumption directly, or indirectly through satisfaction. The findings suggest that food and nutrition professionals in assisted-living should consider the physical profiles of their residents to enhance residents' satisfaction and nutrient intake. Recommendations for exploring residents' perspectives are discussed.

Topological constraints and their breakdown in dynamical evolution

International Nuclear Information System (INIS)

Goldstein, Raymond E; Moffatt, H Keith; Pesci, Adriana I

2012-01-01

A variety of physical and biological systems exhibit dynamical behaviour that has some explicit or implicit topological features. Here, the term ‘topological’ is meant to convey the idea of structures, e.g. physical knots, links or braids, that have some measure of invariance under continuous deformation. Dynamical evolution is then subject to the topological constraints that express this invariance. The simplest problem arising in these systems is the determination of minimum-energy structures (and routes towards these structures) permitted by such constraints, and elucidation of mechanisms by which the constraints may be broken. In more complex nonequilibrium cases there can be recurring singularities associated with topological rearrangements driven by continuous injection of energy. In this brief overview, motivated by an upcoming program on ‘Topological Dynamics in the Physical and Biological Sciences’ at the Isaac Newton Institute for Mathematical Sciences, we present a summary of this class of dynamical systems and discuss examples of important open problems. (invited articles)

The role of social capital in the relationship between physical constraint and mental distress in older adults: a latent interaction model.

Science.gov (United States)

An, Sok; Jang, Yuri

2018-02-01

Building upon the widely known link between physical and mental health, the present study explored the buffering effects of social capital (indicated by social cohesion, social ties, and safety) in the relationship between physical constraint (indicated by chronic conditions and functional disability) and mental distress (indicated by symptoms of depression and anxiety). Using data from 2,264 community-dwelling older adults in the National Social Life, Health, and Aging Project (NSHAP) Wave 2 (M age = 74.51, SD = 6.67), a latent interaction model was tested. The model of mental distress, including both the main effect of physical constraint and social capital and their latent interaction, presented an excellent fit. The latent constructs of physical constraint (β = .54, p social capital (β = -.11, p interaction was also significant (β = -.26, p social capital had a heightened vulnerability to mental distress when faced with physical constraint, whereas the group with a high level of social capital demonstrated resilience. Findings call attention to ways to enhance older individuals' social capital in efforts to promote their health and well-being.

Constraints on cosmic opacity and beyond the standard model physics from cosmological distance measurements

International Nuclear Information System (INIS)

Avgoustidis, Anastasios; Redondo, Javier; Verde, Licia; Jimenez, Raul

2010-04-01

We update constraints on cosmic opacity by combining recent SN Type Ia data compilation with the latest measurements of the Hubble expansion at redshifts between 0 and 2. The new constraint on the parameter ε parametrising deviations from the luminosity-angular diameter distance relation (d L =d A (1+z) 2+ε ), is ε=-0.04 -0.07 +0.08 (2-σ). For the redshift range between 0.2 and 0.35 this corresponds to an opacity Δτ<0.012 (95% C.L.), a factor of 2 stronger than the previous constraint. Various models of beyond the standard model physics that predict violation of photon number conservation contribute to the opacity and can be equally constrained. In this paper we put new limits on axion-like particles, including chameleons, and minicharged particles. (orig.)

Physical activity and senior games participation: benefits, constraints, and behaviors.

Science.gov (United States)

Cardenas, David; Henderson, Karla A; Wilson, Beth E

2009-04-01

The purpose of the article was to examine the physical activity perceptions and behaviors of older adults who were active participants in a statewide senior games (i.e., North Carolina Senior Games; NCSG) program with its focus on year-round involvement through activities in local communities. A random sample of 440 older adults (55 years and older) completed a questionnaire in 2006 about their participation in community-based senior games. A uniqueness of this study is its focus on active older adults, which provides insight into how to maintain physical involvement. Older adults who were most active perceived the most benefits from senior games but did not necessarily have the fewest constraints. This study of NCSG as an organization designed to promote healthy living in communities offered an example of how a social-ecological framework aimed at health promotion can be applied.

Constraints on cosmic opacity and beyond the standard model physics from cosmological distance measurements

Energy Technology Data Exchange (ETDEWEB)

Avgoustidis, Anastasios [Centre for Theoretical Cosmology, DAMTP, CMS, Wilberforce Road, Cambridge CB3 0WA (United Kingdom); Burrage, Clare [Deutsches Elektronen Synchrotron DESY, Notkestrasse 85, D-22607 Hamburg (Germany); Redondo, Javier [Max Planck Institut für Physik, Föhringer Ring 6, D-80805, Munich (Germany); Verde, Licia; Jimenez, Raul, E-mail: a.avgoustidis@damtp.cam.ac.uk, E-mail: clare.burrage@desy.de, E-mail: redondo@mppmu.mpg.de, E-mail: liciaverde@icc.ub.edu, E-mail: raul.jimenez@icc.ub.edu [ICREA and Institute for Sciences of the Cosmos (ICC), University of Barcelona, IEEC, Barcelona 08028 (Spain)

2010-10-01

We update constraints on cosmic opacity by combining recent SN Type Ia data with the latest measurements of the Hubble expansion at redshifts between 0 and 2. The new constraint on the parameter ε parametrising deviations from the luminosity-angular diameter distance relation (d{sub L} = d{sub A}(1+z){sup 2+ε}), is ε = −0.04{sub −0.07}{sup +0.08} (2-σ). For the redshift range between 0.2 and 0.35 this corresponds to an opacity Δτ < 0.012 (95% C.L.), a factor of 2 stronger than the previous constraint. Various models of beyond the standard model physics that predict violation of photon number conservation contribute to the opacity and can be equally constrained. In this paper we put new limits on axion-like particles, including chameleons, and mini-charged particles.

Constraints on cosmic opacity and beyond the standard model physics from cosmological distance measurements

Energy Technology Data Exchange (ETDEWEB)

Avgoustidis, Anastasios [DAMTP, CMS, Cambridge (United Kingdom). Centre for Theoretical Cosmology; Burrage, Clare [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Redondo, Javier [Max-Planck-Institut fuer Physik, Munich (Germany); Verde, Licia; Jimenez, Raul [Barcelona Univ., IEEC (ES). ICREA and Inst. for Sciences of the Cosmos (ICC)

2010-04-15

We update constraints on cosmic opacity by combining recent SN Type Ia data compilation with the latest measurements of the Hubble expansion at redshifts between 0 and 2. The new constraint on the parameter {epsilon} parametrising deviations from the luminosity-angular diameter distance relation (d{sub L}=d{sub A}(1+z){sup 2+{epsilon}}), is {epsilon}=-0.04{sub -0.07}{sup +0.08} (2-{sigma}). For the redshift range between 0.2 and 0.35 this corresponds to an opacity {delta}{tau}<0.012 (95% C.L.), a factor of 2 stronger than the previous constraint. Various models of beyond the standard model physics that predict violation of photon number conservation contribute to the opacity and can be equally constrained. In this paper we put new limits on axion-like particles, including chameleons, and minicharged particles. (orig.)

Generalized Pauli constraints in small atoms

Science.gov (United States)

Schilling, Christian; Altunbulak, Murat; Knecht, Stefan; Lopes, Alexandre; Whitfield, James D.; Christandl, Matthias; Gross, David; Reiher, Markus

2018-05-01

The natural occupation numbers of fermionic systems are subject to nontrivial constraints, which include and extend the original Pauli principle. A recent mathematical breakthrough has clarified their mathematical structure and has opened up the possibility of a systematic analysis. Early investigations have found evidence that these constraints are exactly saturated in several physically relevant systems, e.g., in a certain electronic state of the beryllium atom. It has been suggested that, in such cases, the constraints, rather than the details of the Hamiltonian, dictate the system's qualitative behavior. Here, we revisit this question with state-of-the-art numerical methods for small atoms. We find that the constraints are, in fact, not exactly saturated, but that they lie much closer to the surface defined by the constraints than the geometry of the problem would suggest. While the results seem incompatible with the statement that the generalized Pauli constraints drive the behavior of these systems, they suggest that the qualitatively correct wave-function expansions can in some systems already be obtained on the basis of a limited number of Slater determinants, which is in line with numerical evidence from quantum chemistry.

Physics constraints on the design of fast reactor safety test facilities

International Nuclear Information System (INIS)

Travelli, A.; Meneghetti, D.; Matos, J.; Snelgrove, J.; Shaftman, D.H.; Tzanos, C.; Lam, S.K.; Pennington, E.M.; Woodruff, W.L.

1976-01-01

This paper discusses the physics foundations common to all fast reactor safety test facilities and the constraints which they impose on the design. While detailed design discussions are confined to the experience with six ANL designs, available data from other designs are used to confirm the validity of the considerations and to broaden the scope of the discussion. This helps to view the various designs as a unified effort, to define their potential capabilities, and to assess how they could best complement each other

Credit constraints in rural financial markets in Chile: determinants and consequences

NARCIS (Netherlands)

Reyes, A.

2011-01-01

Using data from two surveys carried out in 2006 and 2008 on 177 farmers in Chile, this study measures access to credit and empirically determine the effects of credit constraints on investment and production for market-oriented farmers in central Chile. More specifically, four issues are dealt

Dynamics and causality constraints

International Nuclear Information System (INIS)

Sousa, Manoelito M. de

2001-04-01

The physical meaning and the geometrical interpretation of causality implementation in classical field theories are discussed. Causality in field theory are kinematical constraints dynamically implemented via solutions of the field equation, but in a limit of zero-distance from the field sources part of these constraints carries a dynamical content that explains old problems of classical electrodynamics away with deep implications to the nature of physicals interactions. (author)

Updated Status of the Global Electroweak Fit and Constraints on New Physics

CERN Document Server

Baak, M; Haller, J; Hoecker, A; Kennedy, D; Moenig, K; Schott, M; Stelzer, J

2012-01-01

We present an update of the Standard Model fit to electroweak precision data. We include newest experimental results on the top quark mass, the W mass and width, and the Higgs boson mass bounds from LEP, Tevatron and the LHC. We also include a new determination of the electromagnetic coupling strength at the Z pole. We find for the Higgs boson mass (96 +31 -24) GeV and (120 +12 -5) GeV when not including and including the direct Higgs searches, respectively. From the latter fit we indirectly determine the W mass to be (80.362 +- 0.013) GeV. We exploit the data to determine experimental constraints on the oblique vacuum polarisation parameters, and confront these with predictions from the Standard Model (SM) and selected SM extensions. By fitting the oblique parameters to the electroweak data we derive allowed regions in the BSM parameter spaces. We revisit and consistently update these constraints for a fourth fourth fermion generation, two Higgs doublet, inert Higgs and littlest Higgs models, models with lar...

Updated Status of the Global Electroweak Fit and Constraints on New Physics

CERN Document Server

Baak, Max; Haller, Johannes; Hoecker, Andreas; Ludwig, Doerthe; Moenig, Klaus; Schott, Matthias; Stelzer, Joerg

2011-01-01

We present an update of the Standard Model fit to electroweak precision data. We include newest experimental results on the top quark mass, the W mass and width, and the Higgs boson mass bounds from LEP, Tevatron and the cLHC. We also include a new determination of the electromagnetic coupling strength at the Z pole. We find for the Higgs boson mass (96 +31 -24) GeV and (120 +12 -5) GeV when not including and including the direct Higgs searches, respectively. From the latter fit we indirectly determine the W mass to be (80.359 +0.017 -0.010) GeV. We exploit the data to determine experimental constraints on the oblique vacuum polarisation parameters, and confront these with predictions from the Standard Model (SM) and selected SM extensions. By fitting the oblique parameters to the electroweak data we derive allowed regions in the BSM parameter spaces. We revisit and consistently update these constraints for a fourth family, two Higgs doublet, inert Higgs and littlest Higgs models, models with large,...

Interrelationship of motivation for and perceived constraints to physical activity participation and the well-being of senior center participants

Science.gov (United States)

Motoko Miyake; Ellen Rodgers

2009-01-01

This study investigated the relationship of motivation for and perceived constraints to physical activity (PA) participation and the well-being of senior center participants. A survey instrument made up of modified versions of the Sport Motivation and Perceived Constraints Scales, the Life Satisfaction Index-Z, and the Geriatric Depression Scale was administered at the...

A note on the CFT origin of the strong constraint of DFT

International Nuclear Information System (INIS)

Betz, André; Blumenhagen, Ralph; Lüst, Dieter; Rennecke, Felix

2014-01-01

In double field theory, motivated by its field theoretic consistency, the level matching condition is generalized to the so-called strong constraint. In this note, it is investigated what the two-dimensional conformal field theory origin of this constraint is. Initially treating the left- and right-movers as independent, we compute the torus partition function as well as a generalized Virasoro-Shapiro amplitude. In non-compact directions the strong constraint arises from the factorization of the Virasoro-Shapiro amplitude over physical states as determined by the modular invariant partition function. From the same argument, along internal toroidal directions, no analogous constraint arises

Unparticle physics constraints from the hydrogen atom

Energy Technology Data Exchange (ETDEWEB)

Wondrak, Michael Florian; Nicolini, Piero; Bleicher, Marcus [Frankfurt Institute for Advanced Studies (FIAS), Frankfurt am Main (Germany); Institut fuer Theoretische Physik, Johann Wolfgang Goethe-Universitaet Frankfurt am Main, Frankfurt am Main (Germany)

2016-07-01

Unparticle stuff has been proposed as an extension of the Standard Model of particle physics by including scale invariant fields. In the framework of effective field theory, it describes the low-energy limit of a so-called Banks-Zaks sector which exhibits scale invariance below an energy scale Λ{sub U}. Unparticle fields are characterized by a non-integer canonical scaling dimension d{sub U}, which leads to unusual properties like resembling a fractional number of (un)particles. The existence of unparticle stuff may be detected experimentally through the interaction with conventional matter. After a review on the unparticle theory and the static potential due to virtual unparticle exchange, we focus on its impact on hydrogen atom energy levels. We obtain the energy shift of the ground state by using Rayleigh-Schroedinger perturbation theory and compare it with experimental data. In this way, bounds on the energy scale Λ{sub U} as a function of d{sub U} are derived. Finally, we offer a comparison with existing constraints in literature like the lepton magnetic anomaly. For some parameter regimes, the hydrogen bound provides competitive results.

Nordic congestion's arrangement as a model for Europe? Physical constraints vs. economic incentives

International Nuclear Information System (INIS)

Glachant, J.-M.; Pignon, V.

2005-01-01

Congestion on power grids seems a physical reality, a 'hard' fact easy to check. Our paper models a different idea: congestion signal may be distorted by transmission system operators (TSOs). Indeed, congestion signals are not physical data but 'home made' conventions directly set by the TSOs in charge of the security of the system. These security norms are not stable and invariable because lines capacity limits are not constant. TSOs, therefore, define the congestion signal on a variable, complex and non-transparent constraint and may manipulate it for monetary purposes or for other personal agenda. In Nordic countries the coexistence of two congestion management methods in a 'Light Handed Regulation' framework makes this opportunistic behaviour even more likely. (author)

New Boundary Constraints for Elliptic Systems used in Grid Generation Problems

Science.gov (United States)

Kaul, Upender K.; Clancy, Daniel (Technical Monitor)

2002-01-01

This paper discusses new boundary constraints for elliptic partial differential equations as used in grid generation problems in generalized curvilinear coordinate systems. These constraints, based on the principle of local conservation of thermal energy in the vicinity of the boundaries, are derived using the Green's Theorem. They uniquely determine the so called decay parameters in the source terms of these elliptic systems. These constraints' are designed for boundary clustered grids where large gradients in physical quantities need to be resolved adequately. It is observed that the present formulation also works satisfactorily for mild clustering. Therefore, a closure for the decay parameter specification for elliptic grid generation problems has been provided resulting in a fully automated elliptic grid generation technique. Thus, there is no need for a parametric study of these decay parameters since the new constraints fix them uniquely. It is also shown that for Neumann type boundary conditions, these boundary constraints uniquely determine the solution to the internal elliptic problem thus eliminating the non-uniqueness of the solution of an internal Neumann boundary value grid generation problem.

Updated status of the global electroweak fit and constraints on new physics

Energy Technology Data Exchange (ETDEWEB)

Baak, M.; Hoecker, A.; Schott, M. [CERN, Geneva (Switzerland); Goebel, M.; Ludwig, D. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Hamburg Univ. (Germany). Inst. fuer Experimentalphysik; Haller, J. [Hamburg Univ. (Germany). Inst. fuer Experimentalphysik; Goettingen Univ. (Germany). II. Physikalisches Inst.; Moenig, K. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Stelzer, J. [Michigan State Univ., East Lansing, MI (United States). Dept. of Physics and Astronomy

2011-07-15

We present an update of the Standard Model fit to electroweak precision data. We include newest experimental results on the top quark mass, the W mass and width, and the Higgs boson mass bounds from LEP, Tevatron and the LHC. We also include a new determination of the electromagnetic coupling strength at the Z pole. We find for the Higgs boson mass 96{sub -24}{sup +31} GeV and 120{sub -5}{sup +12} GeV when not including and including the direct Higgs searches, respectively. From the latter fit we indirectly determine the W mass to be (80.362{+-} 0.013)GeV. We exploit the data to determine experimental constraints on the oblique vacuum polarisation parameters, and confront these with predictions from the Standard Model (SM) and selected SM extensions. By fitting the oblique parameters to the electroweak data we derive allowed regions in the BSM parameter spaces. We revisit and consistently update these constraints for a fourth fermion generation, two Higgs doublet, inert Higgs and littlest Higgs models, models with large, universal or warped extra dimensions and technicolour. In most of the models studied a heavy Higgs boson can be made compatible with the electroweak precision data. (orig.)

Reduction of Constraints: Applicability of the Homogeneity Constraint for Macrobatch 3

International Nuclear Information System (INIS)

Peeler, D.K.

2001-01-01

The Product Composition Control System (PCCS) is used to determine the acceptability of each batch of Defense Waste Processing Facility (DWPF) melter feed in the Slurry Mix Evaporator (SME). This control system imposes several constraints on the composition of the contents of the SME to define acceptability. These constraints relate process or product properties to composition via prediction models. A SME batch is deemed acceptable if its sample composition measurements lead to acceptable property predictions after accounting for modeling, measurement and analytic uncertainties. The baseline document guiding the use of these data and models is ''SME Acceptability Determination for DWPF Process Control (U)'' by Brown and Postles [1996]. A minimum of three PCCS constraints support the prediction of the glass durability from a given SME batch. The Savannah River Technology Center (SRTC) is reviewing all of the PCCS constraints associated with durability. The purpose of this review is to revisit these constraints in light of the additional knowledge gained since the beginning of radioactive operations at DWPF and to identify any supplemental studies needed to amplify this knowledge so that redundant or overly conservative constraints can be eliminated or replaced by more appropriate constraints

What does the closure of context-sensitive constraints mean for determinism, autonomy, self-determination, and agency?

Science.gov (United States)

Juarrero, Alicia

2015-12-01

The role of context-sensitive constraints - first as enablers of complexification and subsequently as regulators that maintain the integrity of self-organized, coherent wholes - has only recently begun to be examined. Conceptualizing such organizational constraints in terms of the operations of far from equilibrium, nonlinear dynamic processes rekindles old metaphysical discussions concerning primary and secondary relations, emergence, causality, and the logic of explanation. In particular, far-from-equilibrium processes allow us to rethink how parts-to-whole and whole-to-parts - so-called "mereological"- relationships are constituted. A renewed understanding of recursive feedback and the role context-dependence plays in generating the boundary conditions and the internal organization of complex adaptive systems in turn allows us to redescribe formal and final cause in such a way as to provide a meaningful sense of heretofore seemingly intractable philosophical problems such as autonomy, self-determination, and agency. Copyright © 2015. Published by Elsevier Ltd.

Big Bang Nucleosynthesis: Impact of Nuclear Physics Uncertainties on Baryonic Matter Density

International Nuclear Information System (INIS)

Smith, Michael Scott; Roberts, Luke F.; Hix, William Raphael; Bruner, Blake D.; Kozub, R.L.; Tytler, David; Fuller, George M.; Lingerfelt, Eric J.; Nesaraja, Caroline D

2008-01-01

We performed new Big Bang Nucleosynthesis simulations with the bigbangonline.org suite of codes to determine, from the nuclear physics perspective, the highest achievable precision of the constraint on the baryon-to-photo ratio η given current observational uncertainties. We also performed sensitivity studies to determine the impact that particular nuclear physics measurements would have on the uncertainties of predicted abundances and on the η constraint.

New Physics constraints from rare b → s + (γ, ℓ+ℓ− decays

Directory of Open Access Journals (Sweden)

Bobeth Christoph

2013-05-01

Full Text Available The experimental measurements of flavor-changing neutral-current B-meson decays governed by b → s + (γ, ℓ+ℓ− transitions have entered a new level of precision. Recent results by Belle, CDF, Babar, and LHCb on B → K(*ℓ+ℓ− and Bs → μ+μ− decays are used in model-(independent analyses to test the Standard Model predictions and to derive stronger constraints on nonstandard contributions. While in agreement with the Standard Model, they still leave sizable room for new physics.

From Kaons to B mesons: Constraints on the Standard Model from Flavour Physics

International Nuclear Information System (INIS)

Ocariz, J.

2007-12-01

The first chapter is a short summary of flavour physics in the Standard Model, and ends with a succinct description of the statistical approach used in CKM fitter. The second chapter discusses CP violation in the Kaon sector: constraints on the CKM matrix from measurements of ε K , ε'/ε, and the rare modes K + → π + νν-bar and K L → π 0 νν-bar are dealt with; the chapter ends with a prospective study on the potential of Kaon physics for the CKM matrix. The next two chapters describe physics analyses performed in the BaBar experiment; the amplitude analysis of B 0 → K + π - π 0 is first presented, followed by a succinct discussion of a preliminary time-dependent amplitude analysis of B 0 → K 0 π + π - . The discussion is finally completed with a qualitative description of a proposal for a combined study of B → Kππ modes to constrain the CKM matrix. The slides made for the presentation of this work have been added at the end of the document

A life course examination of the physical environmental determinants of physical activity behaviour: A "Determinants of Diet and Physical Activity" (DEDIPAC) umbrella systematic literature review.

Science.gov (United States)

Carlin, Angela; Perchoux, Camille; Puggina, Anna; Aleksovska, Katina; Buck, Christoph; Burns, Con; Cardon, Greet; Chantal, Simon; Ciarapica, Donatella; Condello, Giancarlo; Coppinger, Tara; Cortis, Cristina; D'Haese, Sara; De Craemer, Marieke; Di Blasio, Andrea; Hansen, Sylvia; Iacoviello, Licia; Issartel, Johann; Izzicupo, Pascal; Jaeschke, Lina; Kanning, Martina; Kennedy, Aileen; Lakerveld, Jeroen; Chun Man Ling, Fiona; Luzak, Agnes; Napolitano, Giorgio; Nazare, Julie-Anne; Pischon, Tobias; Polito, Angela; Sannella, Alessandra; Schulz, Holger; Sohun, Rhoda; Steinbrecher, Astrid; Schlicht, Wolfgang; Ricciardi, Walter; MacDonncha, Ciaran; Capranica, Laura; Boccia, Stefania

2017-01-01

Participation in regular physical activity is associated with a multitude of health benefits across the life course. However, many people fail to meet PA recommendations. Despite a plethora of studies, the evidence regarding the environmental (physical) determinants of physical activity remains inconclusive. To identify the physical environmental determinants that influence PA across the life course. An online systematic literature search was conducted using MEDLINE, ISI Web of Science, Scopus and SPORTDiscus. The search was limited to studies published in English (January 2004 to April 2016). Only systematic literature reviews (SLRs) and meta-analyses (MAs) of observational studies, that investigated the association between physical determinants and physical activity outcomes, were eligible for inclusion. The extracted data were assessed on the importance of determinants, strength of evidence and methodological quality. The literature search identified 28 SLRs and 3 MAs on 67 physical environmental characteristics potentially related to physical activity that were eligible for inclusion. Among preschool children, a positive association was reported between availability of backyard space and outdoor toys/equipment in the home and overall physical activity. The availability of physical activity programs and equipment within schools, and neighbourhood features such as pedestrian and cyclist safety structure were positively associated with physical activity in children and adolescents. Negative street characteristics, for example, lack of sidewalks and streetlights, were negatively associated with physical activity in adults. Inconsistent associations were reported for the majority of reviewed determinants in adults. This umbrella SLR provided a comprehensive overview of the physical environment determinants of physical activity across the life course and has highlighted, particularly amongst youth, a number of key determinants that may be associated with overall

Geophysical, petrological and mineral physics constraints on Earth's surface topography

Science.gov (United States)

Guerri, Mattia; Cammarano, Fabio; Tackley, Paul J.

2015-04-01

Earth's surface topography is controlled by isostatically compensated density variations within the lithosphere, but dynamic topography - i.e. the topography due to adjustment of surface to mantle convection - is an important component, specially at a global scale. In order to separate these two components it is fundamental to estimate crustal and mantle density structure and rheological properties. Usually, crustal density is constrained from interpretation of available seismic data (mostly VP profiles) based on empirical relationships such those in Brocher [2005]. Mantle density structure is inferred from seismic tomography models. Constant coefficients are used to interpret seismic velocity anomalies in density anomalies. These simplified methods are unable to model the effects that pressure and temperature variations have on mineralogical assemblage and physical properties. Our approach is based on a multidisciplinary method that involves geophysical observables, mineral physics constraints, and petrological data. Mantle density is based on the thermal interpretation of global seismic tomography models assuming various compositional structures, as in Cammarano et al. [2011]. We further constrain the top 150 km by including heat-flow data and considering the thermal evolution of the oceanic lithosphere. Crustal density is calculated as in Guerri and Cammarano [2015] performing thermodynamic modeling of various average chemical compositions proposed for the crust. The modeling, performed with the code PerpleX [Connolly, 2005], relies on the thermodynamic dataset from Holland and Powell [1998]. Compressional waves velocity and crustal layers thickness from the model CRUST 1.0 [Laske et al., 2013] offer additional constrains. The resulting lithospheric density models are tested against gravity (GOCE) data. Various crustal and mantle density models have been tested in order to ascertain the effects that uncertainties in the estimate of those features have on the

A first class constraint generates not a gauge transformation, but a bad physical change: The case of electromagnetism

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

Particle Dark Matter constraints: the effect of Galactic uncertainties

Energy Technology Data Exchange (ETDEWEB)

Benito, Maria; Bernal, Nicolás; Iocco, Fabio [ICTP South American Institute for Fundamental Research Instituto de Física Teórica - Universidade Estadual Paulista (UNESP) Rua Dr. Bento Teobaldo Ferraz 271, 01140-070 São Paulo, SP Brazil (Brazil); Bozorgnia, Nassim; Calore, Francesca, E-mail: mariabenitocst@gmail.com, E-mail: nicolas.bernal@uan.edu.co, E-mail: n.bozorgnia@uva.nl, E-mail: calore@lapth.cnrs.fr, E-mail: fabio.iocco.astro@gmail.com [GRAPPA Institute, Institute for Theoretical Physics Amsterdam and Delta Institute for Theoretical Physics, University of Amsterdam, Science Park 904, 1098 XH Amsterdam (Netherlands)

2017-02-01

Collider, space, and Earth based experiments are now able to probe several extensions of the Standard Model of particle physics which provide viable dark matter candidates. Direct and indirect dark matter searches rely on inputs of astrophysical nature, such as the local dark matter density or the shape of the dark matter density profile in the target in object. The determination of these quantities is highly affected by astrophysical uncertainties. The latter, especially those for our own Galaxy, are ill-known, and often not fully accounted for when analyzing the phenomenology of particle physics models. In this paper we present a systematic, quantitative estimate of how astrophysical uncertainties on Galactic quantities (such as the local galactocentric distance, circular velocity, or the morphology of the stellar disk and bulge) propagate to the determination of the phenomenology of particle physics models, thus eventually affecting the determination of new physics parameters. We present results in the context of two specific extensions of the Standard Model (the Singlet Scalar and the Inert Doublet) that we adopt as case studies for their simplicity in illustrating the magnitude and impact of such uncertainties on the parameter space of the particle physics model itself. Our findings point toward very relevant effects of current Galactic uncertainties on the determination of particle physics parameters, and urge a systematic estimate of such uncertainties in more complex scenarios, in order to achieve constraints on the determination of new physics that realistically include all known uncertainties.

Constraints on Interacting Scalars in 2T Field Theory and No Scale Models in 1T Field Theory

CERN Document Server

Bars, Itzhak

2010-01-01

In this paper I determine the general form of the physical and mathematical restrictions that arise on the interactions of gravity and scalar fields in the 2T field theory setting, in d+2 dimensions, as well as in the emerging shadows in d dimensions. These constraints on scalar fields follow from an underlying Sp(2,R) gauge symmetry in phase space. Determining these general constraints provides a basis for the construction of 2T supergravity, as well as physical applications in 1T-field theory, that are discussed briefly here, and more detail elsewhere. In particular, no scale models that lead to a vanishing cosmological constant at the classical level emerge naturally in this setting.

On-line determination of operating limits incorporating constraint costs and reliability assessment

International Nuclear Information System (INIS)

Meisingset, M.; Lovas, G. G.

1997-01-01

Problems regarding power system operation following deregulation were discussed. The problems arise as a result of the increased power flow pattern created by deregulation and competitive power markets, resulting in power in excess of N-1, (the capacity of transmission lines available), which in turn creates bottlenecks. In a situation like this, constraint costs and security costs (i.e. the cost of supply interruptions) are incurred as the direct result of the deterministic criteria used in reliability assessment. This paper describes an on-line probabilistic method to determine operating limits based on a trade-off between constraint costs and security costs. The probability of the contingencies depend on the existing weather conditions, which therefore has significant impact on the calculated operating limit. In consequence, the proposed method allows power flow to exceed the N-1 limit during normal weather. Under adverse weather conditions the N-1 criteria should be maintained. 15 refs., 13 figs

Teaching Australian Football in Physical Education: Constraints Theory in Practice

Science.gov (United States)

Pill, Shane

2013-01-01

This article outlines a constraints-led process of exploring, modifying, experimenting, adapting, and developing game appreciation known as Game Sense (Australian Sports Commission, 1997; den Duyn, 1996, 1997) for the teaching of Australian football. The game acts as teacher in this constraints-led process. Rather than a linear system that…

Hamiltonian constraint in polymer parametrized field theory

International Nuclear Information System (INIS)

Laddha, Alok; Varadarajan, Madhavan

2011-01-01

Recently, a generally covariant reformulation of two-dimensional flat spacetime free scalar field theory known as parametrized field theory was quantized using loop quantum gravity (LQG) type ''polymer'' representations. Physical states were constructed, without intermediate regularization structures, by averaging over the group of gauge transformations generated by the constraints, the constraint algebra being a Lie algebra. We consider classically equivalent combinations of these constraints corresponding to a diffeomorphism and a Hamiltonian constraint, which, as in gravity, define a Dirac algebra. Our treatment of the quantum constraints parallels that of LQG and obtains the following results, expected to be of use in the construction of the quantum dynamics of LQG: (i) the (triangulated) Hamiltonian constraint acts only on vertices, its construction involves some of the same ambiguities as in LQG and its action on diffeomorphism invariant states admits a continuum limit, (ii) if the regulating holonomies are in representations tailored to the edge labels of the state, all previously obtained physical states lie in the kernel of the Hamiltonian constraint, (iii) the commutator of two (density weight 1) Hamiltonian constraints as well as the operator correspondent of their classical Poisson bracket converge to zero in the continuum limit defined by diffeomorphism invariant states, and vanish on the Lewandowski-Marolf habitat, (iv) the rescaled density 2 Hamiltonian constraints and their commutator are ill-defined on the Lewandowski-Marolf habitat despite the well-definedness of the operator correspondent of their classical Poisson bracket there, (v) there is a new habitat which supports a nontrivial representation of the Poisson-Lie algebra of density 2 constraints.

Generalized Pauli constraints in small atoms

DEFF Research Database (Denmark)

Schilling, Christian; Altunbulak, Murat; Knecht, Stefan

2018-01-01

investigations have found evidence that these constraints are exactly saturated in several physically relevant systems, e.g., in a certain electronic state of the beryllium atom. It has been suggested that, in such cases, the constraints, rather than the details of the Hamiltonian, dictate the system......'s qualitative behavior. Here, we revisit this question with state-of-the-art numerical methods for small atoms. We find that the constraints are, in fact, not exactly saturated, but that they lie much closer to the surface defined by the constraints than the geometry of the problem would suggest. While...

Physical constraints determine the logic of bacterial promoter architectures

Science.gov (United States)

Ezer, Daphne; Zabet, Nicolae Radu; Adryan, Boris

2014-01-01

Site-specific transcription factors (TFs) bind to their target sites on the DNA, where they regulate the rate at which genes are transcribed. Bacterial TFs undergo facilitated diffusion (a combination of 3D diffusion around and 1D random walk on the DNA) when searching for their target sites. Using computer simulations of this search process, we show that the organization of the binding sites, in conjunction with TF copy number and binding site affinity, plays an important role in determining not only the steady state of promoter occupancy, but also the order at which TFs bind. These effects can be captured by facilitated diffusion-based models, but not by standard thermodynamics. We show that the spacing of binding sites encodes complex logic, which can be derived from combinations of three basic building blocks: switches, barriers and clusters, whose response alone and in higher orders of organization we characterize in detail. Effective promoter organizations are commonly found in the E. coli genome and are highly conserved between strains. This will allow studies of gene regulation at a previously unprecedented level of detail, where our framework can create testable hypothesis of promoter logic. PMID:24476912

Optimal residential smart appliances scheduling considering distribution network constraints

Directory of Open Access Journals (Sweden)

Yu-Ree Kim

2016-01-01

Full Text Available As smart appliances (SAs are more widely adopted within distribution networks, residential consumers can contribute to electricity market operations with demand response resources and reduce their electricity bill. However, if the schedules of demand response resources are determined only by the economic electricity rate signal, the schedule can be unfeasible due to the distribution network constraints. Furthermore, it is impossible for consumers to understand the complex physical characteristics and reflect them in their everyday behaviors. This paper introduces the concept of load coordinating retailer (LCR that deals with demand responsive appliances to reduce electrical consumption for the given distribution network constraints. The LCR can play the role of both conventional retailer and aggregated demand response provider for residential customers. It determines the optimal schedules for the aggregated neighboring SAs according to their types within each distribution feeder. The optimization algorithms are developed using Mixed Integer Linear Programming, and the distribution network is solved by the Newton–Raphson AC power flow.

Credit Constraints and Determinants of the Cost of Capital in Vietnamese Manufacturing

DEFF Research Database (Denmark)

Rand, John

2007-01-01

This paper examines the extent to which borrowing constraints restrict firm access to credit and identifies individual, firm, and loan characteristics, which determine the cost of capital in Vietnamese manufacturing. Using direct information from a Vietnamese enterprise survey the paper shows...... to have the necessary time to go through the many administrative difficulties in the formal credit system if they want to "seize the day". Finally, collateralized loans face larger interest rates, explained by the significant influence of "policy lending" in Vietnamese credit markets...

Statistical mechanics of fluids under internal constraints: Rigorous results for the one-dimensional hard rod fluid

International Nuclear Information System (INIS)

Corti, D.S.; Debenedetti, P.G.

1998-01-01

The rigorous statistical mechanics of metastability requires the imposition of internal constraints that prevent access to regions of phase space corresponding to inhomogeneous states. We derive exactly the Helmholtz energy and equation of state of the one-dimensional hard rod fluid under the influence of an internal constraint that places an upper bound on the distance between nearest-neighbor rods. This type of constraint is relevant to the suppression of boiling in a superheated liquid. We determine the effects of this constraint upon the thermophysical properties and internal structure of the hard rod fluid. By adding an infinitely weak and infinitely long-ranged attractive potential to the hard core, the fluid exhibits a first-order vapor-liquid transition. We determine exactly the equation of state of the one-dimensional superheated liquid and show that it exhibits metastable phase equilibrium. We also derive statistical mechanical relations for the equation of state of a fluid under the action of arbitrary constraints, and show the connection between the statistical mechanics of constrained and unconstrained ensembles. copyright 1998 The American Physical Society

Joint cosmic microwave background and weak lensing analysis: constraints on cosmological parameters.

Science.gov (United States)

Contaldi, Carlo R; Hoekstra, Henk; Lewis, Antony

2003-06-06

We use cosmic microwave background (CMB) observations together with the red-sequence cluster survey weak lensing results to derive constraints on a range of cosmological parameters. This particular choice of observations is motivated by their robust physical interpretation and complementarity. Our combined analysis, including a weak nucleosynthesis constraint, yields accurate determinations of a number of parameters including the amplitude of fluctuations sigma(8)=0.89+/-0.05 and matter density Omega(m)=0.30+/-0.03. We also find a value for the Hubble parameter of H(0)=70+/-3 km s(-1) Mpc(-1), in good agreement with the Hubble Space Telescope key-project result. We conclude that the combination of CMB and weak lensing data provides some of the most powerful constraints available in cosmology today.

GNSS Single Frequency, Single Epoch Reliable Attitude Determination Method with Baseline Vector Constraint

Directory of Open Access Journals (Sweden)

Ang Gong

2015-12-01

Full Text Available For Global Navigation Satellite System (GNSS single frequency, single epoch attitude determination, this paper proposes a new reliable method with baseline vector constraint. First, prior knowledge of baseline length, heading, and pitch obtained from other navigation equipment or sensors are used to reconstruct objective function rigorously. Then, searching strategy is improved. It substitutes gradually Enlarged ellipsoidal search space for non-ellipsoidal search space to ensure correct ambiguity candidates are within it and make the searching process directly be carried out by least squares ambiguity decorrelation algorithm (LAMBDA method. For all vector candidates, some ones are further eliminated by derived approximate inequality, which accelerates the searching process. Experimental results show that compared to traditional method with only baseline length constraint, this new method can utilize a priori baseline three-dimensional knowledge to fix ambiguity reliably and achieve a high success rate. Experimental tests also verify it is not very sensitive to baseline vector error and can perform robustly when angular error is not great.

From Mateev's baryogenesis ideas to contemporary cosmological constraints

International Nuclear Information System (INIS)

Kirilova, D.

2011-01-01

Mateev's ideas on baryogenesis and the possibility to constrain new physics on the basis of cosmological observations present the first impulse for the development of the physical cosmology and astroparticle physics in Bulgaria. Contemporary cosmological models of baryogenesis, leptogenesis, primordial nucleosynthesis and cosmological constraints on new physics are discussed

Evaluation of cross-section uncertainties using physical constraints for 238U, 239Pu

International Nuclear Information System (INIS)

De Saint Jean, Cyrille; Privas, Edwin; Archier, Pascal; Noguere, Gilles; Litaize, Olivier; Leconte, Pierre; Bernard, David

2014-01-01

Neutron-induced reactions between 0 eV and 20 MeV are based on various physical properties such as nuclear reaction models, microscopic and integral measurements. Most of the time, the evaluation work is done independently between the resolved resonance range and the continuum, giving rise to mismatches for the cross-sections, larger uncertainties on boundary and no cross-correlation between high-energy domain and resonance range. In addition the use of integral experiment is sometimes only related to central values (evaluation is 'working fine' on a dedicated set of benchmarks) and reductions of uncertainties are not straightforward on cross-sections themselves: working fine could be mathematically reflected by a reduced uncertainty. As the CIELO initiative is to bring experts in each field to propose/discuss these matters, after having presented the status of 238 U and 239 Pu cross-sections covariances evaluation (for JEFF-3.2 as well as the WPEC SG34 subgroup), this paper will present several methodologies that may be used to avoid such effects on covariances. A first idea based on the use of experiments overlapping two energy domains appeared in the near past. It was reviewed and extended to the use of systematic uncertainties (normalisation for example) and for integral experiments as well. In addition, we propose a methodology taking into account physical constraints on an overlapping energy domain where both nuclear reaction models are used (continuity of both cross-sections and derivatives for example). The use of Lagrange multiplier (related to these constraints) in a classical generalised least square procedure will be exposed. Some academic examples will then be presented for both point-wise and multi-group cross-sections to present the methodologies. In addition, new results for 239 Pu will be presented on resonance range and higher energies to reduce capture and fission cross-section uncertainties by using integral experiments (JEZEBEL experiment as

Infrared Constraint on Ultraviolet Theories

Energy Technology Data Exchange (ETDEWEB)

Tsai, Yuhsin [Cornell Univ., Ithaca, NY (United States)

2012-08-01

While our current paradigm of particle physics, the Standard Model (SM), has been extremely successful at explaining experiments, it is theoretically incomplete and must be embedded into a larger framework. In this thesis, we review the main motivations for theories beyond the SM (BSM) and the ways such theories can be constrained using low energy physics. The hierarchy problem, neutrino mass and the existence of dark matter (DM) are the main reasons why the SM is incomplete . Two of the most plausible theories that may solve the hierarchy problem are the Randall-Sundrum (RS) models and supersymmetry (SUSY). RS models usually suffer from strong flavor constraints, while SUSY models produce extra degrees of freedom that need to be hidden from current experiments. To show the importance of infrared (IR) physics constraints, we discuss the flavor bounds on the anarchic RS model in both the lepton and quark sectors. For SUSY models, we discuss the difficulties in obtaining a phenomenologically allowed gaugino mass, its relation to R-symmetry breaking, and how to build a model that avoids this problem. For the neutrino mass problem, we discuss the idea of generating small neutrino masses using compositeness. By requiring successful leptogenesis and the existence of warm dark matter (WDM), we can set various constraints on the hidden composite sector. Finally, to give an example of model independent bounds from collider experiments, we show how to constrain the DM–SM particle interactions using collider results with an effective coupling description.

Constraints on Dbar uplifts

International Nuclear Information System (INIS)

Alwis, S.P. de

2016-01-01

We discuss constraints on KKLT/KKLMMT and LVS scenarios that use anti-branes to get an uplift to a deSitter vacuum, coming from requiring the validity of an effective field theory description of the physics. We find these are not always satisfied or are hard to satisfy.

Exploiting physical constraints for multi-spectral exo-planet detection

Science.gov (United States)

Thiébaut, Éric; Devaney, Nicholas; Langlois, Maud; Hanley, Kenneth

2016-07-01

We derive a physical model of the on-axis PSF for a high contrast imaging system such as GPI or SPHERE. This model is based on a multi-spectral Taylor series expansion of the diffraction pattern and predicts that the speckles should be a combination of spatial modes with deterministic chromatic magnification and weighting. We propose to remove most of the residuals by fitting this model on a set of images at multiple wavelengths and times. On simulated data, we demonstrate that our approach achieves very good speckle suppression without additional heuristic parameters. The residual speckles1, 2 set the most serious limitation in the detection of exo-planets in high contrast coronographic images provided by instruments such as SPHERE3 at the VLT, GPI4, 5 at Gemini, or SCExAO6 at Subaru. A number of post-processing methods have been proposed to remove as much as possible of the residual speckles while preserving the signal from the planets. These methods exploit the fact that the speckles and the planetary signal have different temporal and spectral behaviors. Some methods like LOCI7 are based on angular differential imaging8 (ADI), spectral differential imaging9, 10 (SDI), or on a combination of ADI and SDI.11 Instead of working on image differences, we propose to tackle the exo-planet detection as an inverse problem where a model of the residual speckles is fit on the set of multi-spectral images and, possibly, multiple exposures. In order to reduce the number of degrees of freedom, we impose specific constraints on the spatio-spectral distribution of stellar speckles. These constraints are deduced from a multi-spectral Taylor series expansion of the diffraction pattern for an on-axis source which implies that the speckles are a combination of spatial modes with deterministic chromatic magnification and weighting. Using simulated data, the efficiency of speckle removal by fitting the proposed multi-spectral model is compared to the result of using an approximation

Shaping tissues by balancing active forces and geometric constraints

Science.gov (United States)

Foolen, Jasper; Yamashita, Tadahiro; Kollmannsberger, Philip

2016-02-01

The self-organization of cells into complex tissues during growth and regeneration is a combination of physical-mechanical events and biochemical signal processing. Cells actively generate forces at all stages in this process, and according to the laws of mechanics, these forces result in stress fields defined by the geometric boundary conditions of the cell and tissue. The unique ability of cells to translate such force patterns into biochemical information and vice versa sets biological tissues apart from any other material. In this topical review, we summarize the current knowledge and open questions of how forces and geometry act together on scales from the single cell to tissues and organisms, and how their interaction determines biological shape and structure. Starting with a planar surface as the simplest type of geometric constraint, we review literature on how forces during cell spreading and adhesion together with geometric constraints impact cell shape, stress patterns, and the resulting biological response. We then move on to include cell-cell interactions and the role of forces in monolayers and in collective cell migration, and introduce curvature at the transition from flat cell sheets to three-dimensional (3D) tissues. Fibrous 3D environments, as cells experience them in the body, introduce new mechanical boundary conditions and change cell behaviour compared to flat surfaces. Starting from early work on force transmission and collagen remodelling, we discuss recent discoveries on the interaction with geometric constraints and the resulting structure formation and network organization in 3D. Recent literature on two physiological scenarios—embryonic development and bone—is reviewed to demonstrate the role of the force-geometry balance in living organisms. Furthermore, the role of mechanics in pathological scenarios such as cancer is discussed. We conclude by highlighting common physical principles guiding cell mechanics, tissue patterning and

Determinants of Teachers' Intentions To Teach Physically Active Physical Education Classes.

Science.gov (United States)

Martin, Jeffrey J.; Kulinna, Pamela Hodges; Eklund, Robert C.; Reed, Brett

2001-01-01

Investigated elementary and secondary teachers' intentions to teach physically active physical education classes, examining a model hypothesizing that teachers' intentions were determined by subjective norm, attitude, perceived behavioral control, and self-efficacy. Teacher surveys supported the theories of reasoned action and planned behavior.…

Constraints on the CP-Violating MSSM

CERN Document Server

Arbey, A; Godbole, R M; Mahmoudi, F

2016-01-01

We discuss the prospects for observing CP violation in the MSSM with six CP-violating phases, using a geometric approach to maximise CP-violating observables subject to the experimental upper bounds on electric dipole moments. We consider constraints from Higgs physics, flavour physics, the dark matter relic density and spin-independent scattering cross section with matter.

Eluding the Physical Constraints in a Nonlinear Interaction Sound Synthesis Model for Gesture Guidance

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.

Physical constraints in cell fate specification. A case in point: Microgravity and phenotypes differentiation.

Science.gov (United States)

Masiello, Maria Grazia; Verna, Roberto; Cucina, Alessandra; Bizzarri, Mariano

2018-05-01

Data obtained by studying mammalian cells in absence of gravity strongly support the notion that cell fate specification cannot be understood according to the current molecular model. A paradigmatic case in point is provided by studying cell populations growing in absence of gravity. When the physical constraint (gravity) is 'experimentally removed', cells spontaneously allocate into two morphologically different phenotypes. Such phenomenon is likely enacted by the intrinsic stochasticity, which, in turn, is successively 'canalized' by a specific gene regulatory network. Both phenotypes are thermodynamically and functionally 'compatibles' with the new, modified environment. However, when the two cell subsets are reseeded into the 1g gravity field the two phenotypes collapse into one. Gravity constraints the system in adopting only one phenotype, not by selecting a pre-existing configuration, but more precisely shaping it de-novo through the modification of the cytoskeleton three-dimensional structure. Overall, those findings highlight how macro-scale features are irreducible to lower-scale explanations. The identification of macroscale control parameters - as those depending on the field (gravity, electromagnetic fields) or emerging from the cooperativity among the field's components (tissue stiffness, cell-to-cell connectivity) - are mandatory for assessing boundary conditions for models at lower scales, thus providing a concrete instantiation of top-down effects. Copyright © 2018 Elsevier Ltd. All rights reserved.

Theoretical particle physics

International Nuclear Information System (INIS)

1992-01-01

This report discusses the following topics: heavy quark physics; Chiral Perturbation theory; Skyrmions; quarkonia and nuclear matter; parity violating nuclear matrix elements; how precisely can one determine M U /M D ; weak scale baryogenesis; constraints of baryogenesis form neutrino masses; majorons, double beta decay, supernova 1987A; rare decays; chiral lattice fermions; Pauli-Villars regulator and the Higgs mass bound; and Higgs and Yukawa interactions

Constraint and loneliness in agoraphobia: an empirical investigation.

Science.gov (United States)

Pehlivanidis, A; Koulis, S; Papakostas, Y

2014-01-01

While progress in the aetiopathology and treatment of panic disorder is indisputable, research regarding agoraphobia lacks behind. One significant-yet untested- theory by Guidano and Liotti, suggests the existence of inner representations of fear of "constraint" and fear of "loneliness" as two major schemata, important in the pathogenesis and manifestation of agoraphobia. Activation of these schemata may occur in situations in which the patient: (a) feels as in an inescapable trap (constraint) or (b) alone, unprotected and helpless (loneliness). Upon activation, the "constraint" schema elicits such symptoms as asphyxiation, chest pain, difficult breathing, motor agitation and muscular tension, while the "loneliness" schema elicits such symptoms as sensation of tachycardia, weakness of limbs, trembling or fainting. Activation of these schemata by content-compatible stimuli is expected to trigger various, yet distinct, response patterns, both of which are indiscriminately described within the term "agoraphobia". In order to investigate this hypothesis and its possible clinical applications, several mental and physical probes were applied to 20 patients suffering primarily from agoraphobia, and their responses and performance were recorded. Subjects also completed the "10-item Agoraphobia Questionnaire" prepared by our team aiming at assessing cognitions related to Guidano and Liotti's notion of "loneliness" and "constraint". Breath holding (BH) and Hyperventilation (HV) were selected as physical probes. BH was selected as an easily administered hypercapnea - induced clinical procedure, because of its apparent resemblance to the concept of "constraint". Subjects were instructed to hold their breath for as long as they could and stop at will. Similarly, it was hypothesized that HV might represent a physical "loneliness" probe, since it can elicit such symptoms as dizziness, paraesthesias, stiff muscles, cold hands or feet and trembling, reminiscent of a "collapsing

Abaxial growth and steric constraints guide leaf folding and shape in Acer pseudoplatanus.

Science.gov (United States)

Couturier, Etienne; Brunel, Nicole; Douady, Stéphane; Nakayama, Naomi

2012-08-01

How leaf shape is regulated is a long-standing question in botany. For diverse groups of dicotyledon species, lamina folding along the veins and geometry of the space available for the primordia can explain the palmate leaf morphology. Dubbed the kirigami theory, this hypothesis of fold-dependent leaf shape regulation has remained largely theoretical. Using Acer pseudoplatanus, we investigated the mechanisms behind the two key processes of kirigami leaf development. Cytological examination and quantitative analyses were used to examine the course of the vein-dependent lamina folding. Surgical ablation and tissue culturing were employed to test the effects of physical constraints on primordia growth. The final morphology of leaves growing without steric constraints were predicted mathematically. The cytological examination showed that the lamina's abaxial side along the veins grows substantially more than the adaxial side. The abaxial hypergrowth along the veins and the lamina extension correlated with the lamina folding. When a primordium was released from the physical constraints imposed by the other primordia, it rapidly grew into the newly available space, while maintaining the curvature inward. The morphology of such a leaf was predicted to lack symmetry in the lobe shapes. The enhanced growth on the abaxial side of the lamina along the veins is likely to drive lamina folding. The surgical ablation provided clear support for the space-filling nature of leaf growth; thus, steric constraints play a role in determination of the shapes of folded leaves and probably also of the final leaf morphology.

On quantization of time-dependent systems with constraints

International Nuclear Information System (INIS)

Gadjiev, S A; Jafarov, R G

2007-01-01

The Dirac method of canonical quantization of theories with second-class constraints has to be modified if the constraints depend on time explicitly. A solution of the problem was given by Gitman and Tyutin. In the present work we propose an independent way to derive the rules of quantization for these systems, starting from the physical equivalent theory with trivial non-stationarity

On quantization of time-dependent systems with constraints

International Nuclear Information System (INIS)

Hadjialieva, F.G.; Jafarov, R.G.

1993-07-01

The Dirac method of canonical quantization of theories with second class constraints has to be modified if the constraints depend on time explicitly. A solution of the problem was given by Gitman and Tyutin. In the present work we propose an independent way to derive the rules of quantization for these systems, starting from physical equivalent theory with trivial nonstationarity. (author). 4 refs

On quantization of time-dependent systems with constraints

Energy Technology Data Exchange (ETDEWEB)

Gadjiev, S A; Jafarov, R G [Institute for Physical Problems, Baku State University, AZ11 48 Baku (Azerbaijan)

2007-03-30

The Dirac method of canonical quantization of theories with second-class constraints has to be modified if the constraints depend on time explicitly. A solution of the problem was given by Gitman and Tyutin. In the present work we propose an independent way to derive the rules of quantization for these systems, starting from the physical equivalent theory with trivial non-stationarity.

The Determination and Analysis of Constraints in Resource Use ...

African Journals Online (AJOL)

... Efficiency in Multiple Cropping Systems by Small-Holder Farmers in Ebonyi State, ... and sex discrimination (100 percent) were constraints militating against the ... engagés dans le système de la multi-culture dans l'état d'Ebonyi, au Nigeria.

Latin hypercube sampling with inequality constraints

International Nuclear Information System (INIS)

Iooss, B.; Petelet, M.; Asserin, O.; Loredo, A.

2010-01-01

In some studies requiring predictive and CPU-time consuming numerical models, the sampling design of the model input variables has to be chosen with caution. For this purpose, Latin hypercube sampling has a long history and has shown its robustness capabilities. In this paper we propose and discuss a new algorithm to build a Latin hypercube sample (LHS) taking into account inequality constraints between the sampled variables. This technique, called constrained Latin hypercube sampling (cLHS), consists in doing permutations on an initial LHS to honor the desired monotonic constraints. The relevance of this approach is shown on a real example concerning the numerical welding simulation, where the inequality constraints are caused by the physical decreasing of some material properties in function of the temperature. (authors)

Secure Distributed Detection under Energy Constraint in IoT-Oriented Sensor Networks.

Science.gov (United States)

Zhang, Guomei; Sun, Hao

2016-12-16

We study the secure distributed detection problems under energy constraint for IoT-oriented sensor networks. The conventional channel-aware encryption (CAE) is an efficient physical-layer secure distributed detection scheme in light of its energy efficiency, good scalability and robustness over diverse eavesdropping scenarios. However, in the CAE scheme, it remains an open problem of how to optimize the key thresholds for the estimated channel gain, which are used to determine the sensor's reporting action. Moreover, the CAE scheme does not jointly consider the accuracy of local detection results in determining whether to stay dormant for a sensor. To solve these problems, we first analyze the error probability and derive the optimal thresholds in the CAE scheme under a specified energy constraint. These results build a convenient mathematic framework for our further innovative design. Under this framework, we propose a hybrid secure distributed detection scheme. Our proposal can satisfy the energy constraint by keeping some sensors inactive according to the local detection confidence level, which is characterized by likelihood ratio. In the meanwhile, the security is guaranteed through randomly flipping the local decisions forwarded to the fusion center based on the channel amplitude. We further optimize the key parameters of our hybrid scheme, including two local decision thresholds and one channel comparison threshold. Performance evaluation results demonstrate that our hybrid scheme outperforms the CAE under stringent energy constraints, especially in the high signal-to-noise ratio scenario, while the security is still assured.

Algorithms and ordering heuristics for distributed constraint satisfaction problems

CERN Document Server

Wahbi , Mohamed

2013-01-01

DisCSP (Distributed Constraint Satisfaction Problem) is a general framework for solving distributed problems arising in Distributed Artificial Intelligence.A wide variety of problems in artificial intelligence are solved using the constraint satisfaction problem paradigm. However, there are several applications in multi-agent coordination that are of a distributed nature. In this type of application, the knowledge about the problem, that is, variables and constraints, may be logically or geographically distributed among physical distributed agents. This distribution is mainly due to p

Constraint theory multidimensional mathematical model management

CERN Document Server

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...

Route constraints model based on polychromatic sets

Science.gov (United States)

Yin, Xianjun; Cai, Chao; Wang, Houjun; Li, Dongwu

2018-03-01

With the development of unmanned aerial vehicle (UAV) technology, the fields of its application are constantly expanding. The mission planning of UAV is especially important, and the planning result directly influences whether the UAV can accomplish the task. In order to make the results of mission planning for unmanned aerial vehicle more realistic, it is necessary to consider not only the physical properties of the aircraft, but also the constraints among the various equipment on the UAV. However, constraints among the equipment of UAV are complex, and the equipment has strong diversity and variability, which makes these constraints difficult to be described. In order to solve the above problem, this paper, referring to the polychromatic sets theory used in the advanced manufacturing field to describe complex systems, presents a mission constraint model of UAV based on polychromatic sets.

Constraints on nanomaterial structure from experiment and theory: reconciling partial representations

International Nuclear Information System (INIS)

Mlinar, Vladan

2015-01-01

To facilitate the design and optimization of nanomaterials for a given application it is necessary to understand the relationship between structure and physical properties. For large nanomaterials, there is imprecise structural information so the full structure is only resolved at the level of partial representations. Here we show how to reconcile partial structural representations using constraints from structural characterization measurements and theory to maximally exploit the limited amount of data available from experiment. We determine a range of parameter space where predictive theory can be used to design and optimize the structure. Using an example of variation of chemical composition profile across the interface of two nanomaterials, we demonstrate how, given experimental and theoretical constraints, to find a region of structure-parameter space within which computationally explored partial representations of the full structure will have observable real-world counterparts. (paper)

Differential constraints and exact solutions of nonlinear diffusion equations

International Nuclear Information System (INIS)

Kaptsov, Oleg V; Verevkin, Igor V

2003-01-01

The differential constraints are applied to obtain explicit solutions of nonlinear diffusion equations. Certain linear determining equations with parameters are used to find such differential constraints. They generalize the determining equations used in the search for classical Lie symmetries

Determining the Probability of Violating Upper-Level Wind Constraints for the Launch of Minuteman Ill Ballistic Missiles At Vandenberg Air Force Base

Science.gov (United States)

Shafer, Jaclyn A.; Brock, Tyler M.

2013-01-01

The 30th Operational Support Squadron Weather Flight (30 OSSWF) provides comprehensive weather services to the space program at Vandenberg Air Force Base (VAFB) in California. One of their responsibilities is to monitor upper-level winds to ensure safe launch operations of the Minuteman Ill ballistic missile. The 30 OSSWF requested the Applied Meteorology Unit (AMU) analyze VAFB sounding data to determine the probability of violating (PoV) upper-level thresholds for wind speed and shear constraints specific to this launch vehicle, and to develop a graphical user interface (GUI) that will calculate the PoV of each constraint on the day of launch. The AMU suggested also including forecast sounding data from the Rapid Refresh (RAP) model. This would provide further insight for the launch weather officers (LWOs) when determining if a wind constraint violation will occur over the next few hours, and help to improve the overall upper winds forecast on launch day.

Dynamical systems with first- and second-class constraints. II. Local-symmetry transformations

International Nuclear Information System (INIS)

Chitaia, N.P.; Gogilidze, S.A.; Surovtsev, Y.S.

1997-01-01

In the framework of the generalized Hamiltonian formalism by Dirac, local symmetries of dynamical systems with first- and second-class constraints are investigated. The method of constructing the generator of local-symmetry transformations is presented both for theories with an algebra of constraints of a special form (a majority of the physically interesting theories) and in the general case without restrictions on the algebra of constraints. It is proven that second-class constraints do not contribute to the transformation law of the local symmetry entirely stipulated by all the first-class constraints. A mechanism of the occurrence of higher derivatives of coordinates and group parameters in the symmetry transformation law in Noether close-quote s second theorem is elucidated. In the latter case it is shown that the obtained transformations of symmetry are canonical in the extended (by Ostrogradsky) phase space. It is thereby shown that in the general case the degeneracy of theories with first- and second-class constraints is due to their invariance under local-symmetry transformations. copyright 1997 The American Physical Society

Sterile neutrino constraints from cosmology

DEFF Research Database (Denmark)

Hamann, Jan; Hannestad, Steen; Raffelt, Georg G.

2012-01-01

The presence of light particles beyond the standard model's three neutrino species can profoundly impact the physics of decoupling and primordial nucleosynthesis. I review the observational signatures of extra light species, present constraints from recent data, and discuss the implications of po...... of possible sterile neutrinos with O(eV)-masses for cosmology....

Block Pickard Models for Two-Dimensional Constraints

DEFF Research Database (Denmark)

Forchhammer, Søren; Justesen, Jørn

2009-01-01

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...... for the domino tiling constraint represented by a quaternary alphabet. PRF models are also presented for higher order constraints, including the no isolated bits (n.i.b.) constraint, and a minimum distance 3 constraint by defining super symbols on blocks of binary symbols....

Socioeconomic Determinants of Physical Inactivity among Japanese Workers

OpenAIRE

Kumagai, Narimasa

2012-01-01

Background: Half of Japanese workers are physically inactive, but there are no studies on the relation between the leisure-time physical inactivity of Japanese workers and their socioeconomic status. The proportion of female workers who are physically inactive has been larger than that of male workers. Objectives: Using micro-data from nationwide surveys in Japan, this study explored the gender differences in socioeconomic determinants of leisure-time physical inactivity. Methods: We first es...

Motion and deformation estimation from medical imagery by modeling sub-structure interaction and constraints

KAUST Repository

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 Constraints on the running-mass inflation model

OpenAIRE

Covi, Laura; Lyth, David H.; Melchiorri, Alessandro

2002-01-01

We evaluate new observational constraints on the two-parameter scale-dependent spectral index predicted by the running-mass inflation model by combining the latest Cosmic Microwave Background (CMB) anisotropy measurements with the recent 2dFGRS data on the matter power spectrum, with Lyman $\\alpha $ forest data and finally with theoretical constraints on the reionization redshift. We find that present data still allow significant scale-dependence of $n$, which occurs in a physically reasonabl...

Secure Distributed Detection under Energy Constraint in IoT-Oriented Sensor Networks

Directory of Open Access Journals (Sweden)

Guomei Zhang

2016-12-01

Full Text Available We study the secure distributed detection problems under energy constraint for IoT-oriented sensor networks. The conventional channel-aware encryption (CAE is an efficient physical-layer secure distributed detection scheme in light of its energy efficiency, good scalability and robustness over diverse eavesdropping scenarios. However, in the CAE scheme, it remains an open problem of how to optimize the key thresholds for the estimated channel gain, which are used to determine the sensor’s reporting action. Moreover, the CAE scheme does not jointly consider the accuracy of local detection results in determining whether to stay dormant for a sensor. To solve these problems, we first analyze the error probability and derive the optimal thresholds in the CAE scheme under a specified energy constraint. These results build a convenient mathematic framework for our further innovative design. Under this framework, we propose a hybrid secure distributed detection scheme. Our proposal can satisfy the energy constraint by keeping some sensors inactive according to the local detection confidence level, which is characterized by likelihood ratio. In the meanwhile, the security is guaranteed through randomly flipping the local decisions forwarded to the fusion center based on the channel amplitude. We further optimize the key parameters of our hybrid scheme, including two local decision thresholds and one channel comparison threshold. Performance evaluation results demonstrate that our hybrid scheme outperforms the CAE under stringent energy constraints, especially in the high signal-to-noise ratio scenario, while the security is still assured.

Physics conceptual design for the MFTF-B transition coil

International Nuclear Information System (INIS)

Baldwin, D.E.; Bulmer, R.H.

1982-01-01

The physics constraints related to finite-β equilibria, β limits due to curvature-driven MHD modes, and ion transport in the central cell. These physics constraints had to be satisfied subject to certain non-physics constraints. Principal among these were the geometric and structural features of the existing MFTF-B magnet set and the required access for neutral beams for pumping. These constraints and their origins are discussed

Multiparameter elastic full waveform inversion with facies-based constraints

Science.gov (United States)

Zhang, Zhen-dong; Alkhalifah, Tariq; Naeini, Ehsan Zabihi; Sun, Bingbing

2018-06-01

Full waveform inversion (FWI) incorporates all the data characteristics to estimate the parameters described by the assumed physics of the subsurface. However, current efforts to utilize FWI beyond improved acoustic imaging, like in reservoir delineation, faces inherent challenges related to the limited resolution and the potential trade-off between the elastic model parameters. Some anisotropic parameters are insufficiently updated because of their minor contributions to the surface collected data. Adding rock physics constraints to the inversion helps mitigate such limited sensitivity, but current approaches to add such constraints are based on including them as a priori knowledge mostly valid around the well or as a global constraint for the whole area. Since similar rock formations inside the Earth admit consistent elastic properties and relative values of elasticity and anisotropy parameters (this enables us to define them as a seismic facies), utilizing such localized facies information in FWI can improve the resolution of inverted parameters. We propose a novel approach to use facies-based constraints in both isotropic and anisotropic elastic FWI. We invert for such facies using Bayesian theory and update them at each iteration of the inversion using both the inverted models and a priori information. We take the uncertainties of the estimated parameters (approximated by radiation patterns) into consideration and improve the quality of estimated facies maps. Four numerical examples corresponding to different acquisition, physical assumptions and model circumstances are used to verify the effectiveness of the proposed method.

Multiparameter Elastic Full Waveform Inversion with Facies-based Constraints

Science.gov (United States)

Zhang, Zhen-dong; Alkhalifah, Tariq; Naeini, Ehsan Zabihi; Sun, Bingbing

2018-03-01

Full waveform inversion (FWI) incorporates all the data characteristics to estimate the parameters described by the assumed physics of the subsurface. However, current efforts to utilize full waveform inversion beyond improved acoustic imaging, like in reservoir delineation, faces inherent challenges related to the limited resolution and the potential trade-off between the elastic model parameters. Some anisotropic parameters are insufficiently updated because of their minor contributions to the surface collected data. Adding rock physics constraints to the inversion helps mitigate such limited sensitivity, but current approaches to add such constraints are based on including them as a priori knowledge mostly valid around the well or as a global constraint for the whole area. Since similar rock formations inside the Earth admit consistent elastic properties and relative values of elasticity and anisotropy parameters (this enables us to define them as a seismic facies), utilizing such localized facies information in FWI can improve the resolution of inverted parameters. We propose a novel approach to use facies-based constraints in both isotropic and anisotropic elastic FWI. We invert for such facies using Bayesian theory and update them at each iteration of the inversion using both the inverted models and a prior information. We take the uncertainties of the estimated parameters (approximated by radiation patterns) into consideration and improve the quality of estimated facies maps. Four numerical examples corresponding to different acquisition, physical assumptions and model circumstances are used to verify the effectiveness of the proposed method.

Multiparameter Elastic Full Waveform Inversion with Facies-based Constraints

KAUST Repository

Zhang, Zhendong

2018-03-20

Full waveform inversion (FWI) incorporates all the data characteristics to estimate the parameters described by the assumed physics of the subsurface. However, current efforts to utilize full waveform inversion beyond improved acoustic imaging, like in reservoir delineation, faces inherent challenges related to the limited resolution and the potential trade-off between the elastic model parameters. Some anisotropic parameters are insufficiently updated because of their minor contributions to the surface collected data. Adding rock physics constraints to the inversion helps mitigate such limited sensitivity, but current approaches to add such constraints are based on including them as a priori knowledge mostly valid around the well or as a global constraint for the whole area. Since similar rock formations inside the Earth admit consistent elastic properties and relative values of elasticity and anisotropy parameters (this enables us to define them as a seismic facies), utilizing such localized facies information in FWI can improve the resolution of inverted parameters. We propose a novel approach to use facies-based constraints in both isotropic and anisotropic elastic FWI. We invert for such facies using Bayesian theory and update them at each iteration of the inversion using both the inverted models and a prior information. We take the uncertainties of the estimated parameters (approximated by radiation patterns) into consideration and improve the quality of estimated facies maps. Four numerical examples corresponding to different acquisition, physical assumptions and model circumstances are used to verify the effectiveness of the proposed method.

The Relationship between Leisure Constraints, Constraint Negotiation Strategies and Facilitators with Recreational Sport Activity Participation of College Students

Science.gov (United States)

Kocak, Funda

2017-01-01

The aim of this study is to determine the constraints in participating the leisure activities for college students, the strategies of negotiation regarding these constraints and the relationship between the facilitators and activity participation. The population of the study consists of currently registered students from Ankara University.…

Dark matter constraints in the minimal and nonminimal supersymmetric standard model

International Nuclear Information System (INIS)

Stephan, A.

1998-01-01

We determine the allowed parameter space and the particle spectra of the minimal SUSY standard model (MSSM) and nonminimal SUSY standard model (NMSSM) imposing correct electroweak gauge symmetry breaking and recent experimental constraints. The parameters of the models are evolved with the SUSY renormalization group equations assuming universality at the grand unified scale. Applying the new unbounded from below constraints we can exclude the lightest SUSY particle singlinos and light scalar and pseudoscalar Higgs singlets of the NMSSM. This exclusion removes the experimental possibility to distinguish between the MSSM and NMSSM via the recently proposed search for an additional cascade produced in the decay of the B-ino into the LSP singlino. Furthermore, the effects of the dark matter condition for the MSSM and NMSSM are investigated and the differences concerning the parameter space, the SUSY particle, and Higgs sector are discussed. thinsp copyright 1998 The American Physical Society

Input-to-State Stabilizing MPC for Neutrally Stable Linear Systems subject to Input Constraints

NARCIS (Netherlands)

Kim, Jung-Su; Yoon, Tae-Woong; Jadbabaie, Ali; Persis, Claudio De

2004-01-01

MPC(Model Predictive Control) is representative of control methods which are able to handle physical constraints. Closed-loop stability can therefore be ensured only locally in the presence of constraints of this type. However, if the system is neutrally stable, and if the constraints are imposed

The Purine Bias of Coding Sequences is Determined by Physicochemical Constraints on Proteins.

Science.gov (United States)

Ponce de Leon, Miguel; de Miranda, Antonio Basilio; Alvarez-Valin, Fernando; Carels, Nicolas

2014-01-01

For this report, we analyzed protein secondary structures in relation to the statistics of three nucleotide codon positions. The purpose of this investigation was to find which properties of the ribosome, tRNA or protein level, could explain the purine bias (Rrr) as it is observed in coding DNA. We found that the Rrr pattern is the consequence of a regularity (the codon structure) resulting from physicochemical constraints on proteins and thermodynamic constraints on ribosomal machinery. The physicochemical constraints on proteins mainly come from the hydropathy and molecular weight (MW) of secondary structures as well as the energy cost of amino acid synthesis. These constraints appear through a network of statistical correlations, such as (i) the cost of amino acid synthesis, which is in favor of a higher level of guanine in the first codon position, (ii) the constructive contribution of hydropathy alternation in proteins, (iii) the spatial organization of secondary structure in proteins according to solvent accessibility, (iv) the spatial organization of secondary structure according to amino acid hydropathy, (v) the statistical correlation of MW with protein secondary structures and their overall hydropathy, (vi) the statistical correlation of thymine in the second codon position with hydropathy and the energy cost of amino acid synthesis, and (vii) the statistical correlation of adenine in the second codon position with amino acid complexity and the MW of secondary protein structures. Amino acid physicochemical properties and functional constraints on proteins constitute a code that is translated into a purine bias within the coding DNA via tRNAs. In that sense, the Rrr pattern within coding DNA is the effect of information transfer on nucleotide composition from protein to DNA by selection according to the codon positions. Thus, coding DNA structure and ribosomal machinery co-evolved to minimize the energy cost of protein coding given the functional

Determining the Probability of Violating Upper-Level Wind Constraints for the Launch of Minuteman III Ballistic Missiles at Vandenberg Air Force Base

Science.gov (United States)

Shafer, Jaclyn A.; Brock, Tyler M.

2012-01-01

The 30th Operational Support Squadron Weather Flight (30 OSSWF) provides comprehensive weather services to the space program at Vandenberg Air Force Base (VAFB) in California. One of their responsibilities is to monitor upper-level winds to ensure safe launch operations of the Minuteman Ill ballistic missile. The 30 OSSWF tasked the Applied Meteorology Unit (AMU) to analyze VAFB sounding data with the goal of determining the probability of violating (PoV) their upper-level thresholds for wind speed and shear constraints specific to this launch vehicle, and to develop a tool that will calculate the PoV of each constraint on the day of launch. In order to calculate the probability of exceeding each constraint, the AMU collected and analyzed historical data from VAFB. The historical sounding data were retrieved from the National Oceanic and Atmospheric Administration Earth System Research Laboratory archive for the years 1994-2011 and then stratified into four sub-seasons: January-March, April-June, July-September, and October-December. The AMU determined the theoretical distributions that best fit the maximum wind speed and maximum wind shear datasets and applied this information when calculating the averages and standard deviations needed for the historical and real-time PoV calculations. In addition, the AMU included forecast sounding data from the Rapid Refresh model. This information provides further insight for the launch weather officers (LWOs) when determining if a wind constraint violation will occur over the next few hours on the day of launch. The AMU developed an interactive graphical user interface (GUI) in Microsoft Excel using Visual Basic for Applications. The GUI displays the critical sounding data easily and quickly for LWOs on day of launch. This tool will replace the existing one used by the 30 OSSWF, assist the LWOs in determining the probability of exceeding specific wind threshold values, and help to improve the overall upper winds forecast for

New constraints on the running-mass inflation model

International Nuclear Information System (INIS)

Covi, L.; Lyth, D.H.; Melchiorri, A.

2002-10-01

We evaluate new observational constraints on the two-parameter scale-dependent spectral index predicted by the running-mass inflation model by combining the latest cosmic microwave background (CMB) anisotropy measurements with the recent 2dFGRS data on the matter power spectrum, with Lyman α forest data and finally with theoretical constraints on the reionization redshift. We find that present data still allow significant scale-dependence of n, which occurs in a physically reasonable regime of parameter space. (orig.)

Determinant Factors of Physical Fitness in European Children

DEFF Research Database (Denmark)

Zaqout, Mahmoud; Vyncke, Krishna; Moreno, Luis A.

2016-01-01

Objectives: This study was designed to explore the determinants of physical fitness in European children aged 6–11 years, cross-sectionally and longitudinally.Methods: There were sufficient data on 4903 children (50.6 % girls) on measured physical fitness (cardio-respiratory, muscular strength, f...

Molecular Evolutionary Constraints that Determine the Avirulence State of Clostridium botulinum C2 Toxin.

Science.gov (United States)

Prisilla, A; Prathiviraj, R; Chellapandi, P

2017-04-01

Clostridium botulinum (group-III) is an anaerobic bacterium producing C2 toxin along with botulinum neurotoxins. C2 toxin is belonged to binary toxin A family in bacterial ADP-ribosylation superfamily. A structural and functional diversity of binary toxin A family was inferred from different evolutionary constraints to determine the avirulence state of C2 toxin. Evolutionary genetic analyses revealed evidence of C2 toxin cluster evolution through horizontal gene transfer from the phage or plasmid origins, site-specific insertion by gene divergence, and homologous recombination event. It has also described that residue in conserved NAD-binding core, family-specific domain structure, and functional motifs found to predetermine its virulence state. Any mutational changes in these residues destabilized its structure-function relationship. Avirulent mutants of C2 toxin were screened and selected from a crucial site required for catalytic function of C2I and pore-forming function of C2II. We found coevolved amino acid pairs contributing an essential role in stabilization of its local structural environment. Avirulent toxins selected in this study were evaluated by detecting evolutionary constraints in stability of protein backbone structure, folding and conformational dynamic space, and antigenic peptides. We found 4 avirulent mutants of C2I and 5 mutants of C2II showing more stability in their local structural environment and backbone structure with rapid fold rate, and low conformational flexibility at mutated sites. Since, evolutionary constraints-free mutants with lack of catalytic and pore-forming function suggested as potential immunogenic candidates for treating C. botulinum infected poultry and veterinary animals. Single amino acid substitution in C2 toxin thus provides a major importance to understand its structure-function link, not only of a molecule but also of the pathogenesis.

Theoretical high energy physics

International Nuclear Information System (INIS)

Lee, T.D.

1991-01-01

This report discusses theoretical research in high energy physics at Columbia University. Some of the research topics discussed are: quantum chromodynamics with dynamical fermions; lattice gauge theory; scattering of neutrinos by photons; atomic physics constraints on the properties of ultralight-ultraweak gauge bosons; black holes; Chern- Simons physics; S-channel theory of superconductivity; charged boson system; gluon-gluon interactions; high energy scattering in the presence of instantons; anyon physics; causality constraints on primordial magnetic manopoles; charged black holes with scalar hair; properties of Chern-Aimona-Higgs solitons; and extended inflationary universe

Managing Constraint Generators in Retail Design Processes

DEFF Research Database (Denmark)

Münster, Mia Borch; Haug, Anders

case studies of fashion store design projects, the present paper addresses this gap. The and six case studies of fashion store design projects, the present paper sheds light on the types of constraints generated by the relevant constraint generators. The paper shows that in the cases studied......Retail design concepts are complex designs meeting functional and aesthetic demands. During a design process a retail designer has to consider various constraint generators such as stakeholder interests, physical limitations and restrictions. Obviously the architectural site, legislators...... and landlords need to be considered as well as the interest of the client and brand owner. Furthermore the users need to be taken into account in order to develop an interesting and functional shopping and working environments. Finally, suppliers and competitors may influence the design with regard...

On covariant quantization of massive superparticle with first class constraints

International Nuclear Information System (INIS)

Huq, M.

1990-02-01

We use the technique of Batalin and Fradkin to convert the second class fermionic constraints of the massive superparticle into first class constraints. Then the Batalin-Vilkovisky formalism has been used to quantize covariantly the resulting theory. Appropriate gauge fixing conditions lead to a completely quadratic action. Some interesting properties of the physical space wave functions are discussed. (author). 16 refs

Standard test method for determination of resistance to stable crack extension under low-constraint conditions

CERN Document Server

American Society for Testing and Materials. Philadelphia

2006-01-01

1.1 This standard covers the determination of the resistance to stable crack extension in metallic materials in terms of the critical crack-tip-opening angle (CTOAc), ψc and/or the crack-opening displacement (COD), δ5 resistance curve (1). This method applies specifically to fatigue pre-cracked specimens that exhibit low constraint (crack-length-to-thickness and un-cracked ligament-to-thickness ratios greater than or equal to 4) and that are tested under slowly increasing remote applied displacement. The recommended specimens are the compact-tension, C(T), and middle-crack-tension, M(T), specimens. The fracture resistance determined in accordance with this standard is measured as ψc (critical CTOA value) and/or δ5 (critical COD resistance curve) as a function of crack extension. Both fracture resistance parameters are characterized using either a single-specimen or multiple-specimen procedures. These fracture quantities are determined under the opening mode (Mode I) of loading. Influences of environment a...

Rigorous constraints on the matrix elements of the energy–momentum tensor

Directory of Open Access Journals (Sweden)

Peter Lowdon

2017-11-01

Full Text Available The structure of the matrix elements of the energy–momentum tensor play an important role in determining the properties of the form factors A(q2, B(q2 and C(q2 which appear in the Lorentz covariant decomposition of the matrix elements. In this paper we apply a rigorous frame-independent distributional-matching approach to the matrix elements of the Poincaré generators in order to derive constraints on these form factors as q→0. In contrast to the literature, we explicitly demonstrate that the vanishing of the anomalous gravitomagnetic moment B(0 and the condition A(0=1 are independent of one another, and that these constraints are not related to the specific properties or conservation of the individual Poincaré generators themselves, but are in fact a consequence of the physical on-shell requirement of the states in the matrix elements and the manner in which these states transform under Poincaré transformations.

Architectural constraints in IEC 61508: Do they have the intended effect?

International Nuclear Information System (INIS)

Lundteigen, Mary Ann; Rausand, Marvin

2009-01-01

The standards IEC 61508 and IEC 61511 employ architectural constraints to avoid that quantitative assessments alone are used to determine the hardware layout of safety instrumented systems (SIS). This article discusses the role of the architectural constraints, and particularly the safe failure fraction (SFF) as a design parameter to determine the hardware fault tolerance (HFT) and the redundancy level for SIS. The discussion is based on examples from the offshore oil and gas industry, but should be relevant for all applications of SIS. The article concludes that architectural constraints may be required to compensate for systematic failures, but the architectural constraints should not be determined based on the SFF. The SFF is considered to be an unnecessary concept

A Three-Box Model of Thermohaline Circulation under the Energy Constraint

International Nuclear Information System (INIS)

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. (geophysics, astronomy, and astrophysics)

Fermion pair production in $e^+e^-$ collisions at 189-209 GeV and constraints on physics beyond the Standard Model

CERN Document Server

Schael, S.; Bruneliere, R.; De Bonis, I.; Decamp, D.; Goy, C.; Jezequel, S.; Lees, J.-P.; Martin, F.; Merle, E.; Minard, M.-N.; Pietrzyk, B.; Trocme, B.; Bravo, S.; Casado, M.P.; Chmeissani, M.; Crespo, J.M.; Fernandez, E.; Fernandez-Bosman, M.; Garrido, Ll.; Martinez, M.; Pacheco, A.; Ruiz, H.; Colaleo, A.; Creanza, D.; De Filippis, N.; de Palma, M.; Iaselli, G.; Maggi, G.; Maggi, M.; Nuzzo, S.; Ranieri, A.; Raso, G.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Tricomi, A.; Zito, G.; Huang, X.; Lin, J.; Ouyang, Q.; Wang, T.; Xie, Y.; Xu, R.; Xue, S.; Zhang, J.; Zhang, L.; Zhao, W.; Abbaneo, D.; Barklow, T.; Buchmuller, O.; Cattaneo, M.; Clerbaux, B.; Drevermann, H.; Forty, R.W.; Frank, M.; Gianotti, F.; Hansen, J.B.; Harvey, J.; Hutchcroft, D.E.; Janot, P.; Jost, B.; Kado, M.; Mato, P.; Moutoussi, A.; Ranjard, F.; Rolandi, L.; Schlatter, D.; Teubert, F.; Valassi, A.; Videau, I.; Badaud, F.; Dessagne, S.; Falvard, A.; Fayolle, D.; Gay, P.; Jousset, J.; Michel, B.; Monteil, S.; Pallin, D.; Pascolo, J.M.; Perret, P.; Hansen, J.D.; Hansen, J.R.; Hansen, P.H.; Kraan, A.C.; Nilsson, B.S.; Kyriakis, A.; Markou, C.; Simopoulou, E.; Vayaki, A.; Zachariadou, K.; Blondel, A.; Brient, J.-C.; Machefert, F.; Rouge, A.; Videau, H.; Ciulli, V.; Focardi, E.; Parrini, G.; Antonelli, A.; Antonelli, M.; Bencivenni, G.; Bossi, F.; Capon, G.; Cerutti, F.; Chiarella, V.; Laurelli, P.; Mannocchi, G.; Murtas, G.P.; Passalacqua, L.; Kennedy, J.; Lynch, J.G.; Negus, P.; O'Shea, V.; Thompson, A.S.; Wasserbaech, S.; Cavanaugh, R.; Dhamotharan, S.; Geweniger, C.; Hanke, P.; Hepp, V.; Kluge, E.E.; Putzer, A.; Stenzel, H.; Tittel, K.; Wunsch, M.; Rutherford, S.A.; Sedgbeer, J.K.; Thompson, J.C.; White, R.; Ghete, V.M.; Girtler, P.; Kneringer, E.; Kuhn, D.; Rudolph, G.; Bouhova-Thacker, E.; Bowdery, C.K.; Clarke, D.P.; Ellis, G.; Finch, A.J.; Foster, F.; Hughes, G.; Jones, R.W.L.; Pearson, M.R.; Robertson, N.A.; Smizanska, M.; van der Aa, O.; Delaere, C.; Leibenguth, G.; Lemaitre, V.; Blumenschein, U.; Holldorfer, F.; Jakobs, K.; Kayser, F.; Muller, A.-S.; Quast, G.; Renk, B.; Sander, H.-G.; Schmeling, S.; Wachsmuth, H.; Zeitnitz, C.; Ziegler, T.; Bonissent, A.; Coyle, P.; Curtil, C.; Ealet, A.; Fouchez, D.; Payre, P.; Tilquin, A.; Ragusa, F.; David, A.; Dietl, H.; Ganis, G.; Huttmann, K.; Lutjens, G.; Manner, W.; Moser, H.-G.; Settles, R.; Villegas, M.; Wolf, G.; Boucrot, J.; Callot, O.; Davier, M.; Duflot, L.; Grivaz, J.-F.; Heusse, Ph.; Jacholkowska, A.; Serin, L.; Veillet, J.-J.; Azzurri, P.; Bagliesi, Giuseppe; Boccali, T.; Foa, L.; Giammanco, A.; Giassi, A.; Ligabue, F.; Messineo, A.; Palla, F.; Sanguinetti, G.; Sciaba, A.; Sguazzoni, G.; Spagnolo, P.; Tenchini, R.; Venturi, A.; Verdini, P.G.; Awunor, O.; Blair, G.A.; Cowan, G.; Garcia-Bellido, A.; Green, M.G.; Medcalf, T.; Misiejuk, A.; Strong, J.A.; Teixeira-Dias, P.; Clifft, R.W.; Edgecock, T.R.; Norton, P.R.; Tomalin, I.R.; Ward, J.J.; Bloch-Devaux, Brigitte; Boumediene, D.; Colas, P.; Fabbro, B.; Lancon, E.; Lemaire, M.-C.; Locci, E.; Perez, P.; Rander, J.; Tuchming, B.; Vallage, B.; Litke, A.M.; Taylor, G.; Booth, C.N.; Cartwright, S.; Combley, F.; Hodgson, P.N.; Lehto, M.; Thompson, L.F.; Bohrer, A.; Brandt, S.; Grupen, C.; Hess, J.; Ngac, A.; Prange, G.; Borean, C.; Giannini, G.; He, H.; Putz, J.; Rothberg, J.; Armstrong, S.R.; Berkelman, K.; Cranmer, K.; Ferguson, D.P.S.; Gao, Y.; Gonzalez, S.; Hayes, O.J.; Hu, H.; Jin, S.; Kile, J.; McNamara, P.A., III; Nielsen, J.; Pan, Y.B.; von Wimmersperg-Toeller, J.H.; Wiedenmann, W.; Wu, J.; Wu, Sau Lan; Wu, X.; Zobernig, G.; USA; Dissertori, G.

2007-01-01

Cross sections, angular distributions and forward-backward asymmetries are presented, of two-fermion events produced in e+e- collisions at centre-of-mass energies from 189 to 209 GeV at LEP, measured with the ALEPH detector. Results for e+e-, mu+mu-, tau+tau-, qq, bb and cc production are in agreement with the Standard Model predictions. Constraints are set on scenarios of new physics such as four-fermion contact interactions, leptoquarks, Z' bosons, TeV-scale quantum gravity and R-parity violating squarks and sneutrinos.

Constraints on relaxation rates for N-level quantum systems

International Nuclear Information System (INIS)

Schirmer, S.G.; Solomon, A.I.

2004-01-01

We study the constraints imposed on the population and phase relaxation rates by the physical requirement of completely positive evolution for open N-level systems. The Lindblad operators that govern the evolution of the system are expressed in terms of observable relaxation rates, explicit formulas for the decoherence rates due to population relaxation are derived, and it is shown that there are additional, nontrivial constraints on the pure dephasing rates for N>2. Explicit, experimentally testable inequality constraints for the decoherence rates are derived for three- and four-level systems, and the implications of the results are discussed for generic ladder, Λ, and V systems and transitions between degenerate energy levels

Constraint Differentiation

DEFF Research Database (Denmark)

Mödersheim, Sebastian Alexander; Basin, David; Viganò, Luca

2010-01-01

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...... results show that constraint differentiation substantially reduces search and considerably improves the performance of OFMC, enabling its application to a wider class of problems....

Constraint-based scheduling applying constraint programming to scheduling problems

CERN Document Server

Baptiste, Philippe; Nuijten, Wim

2001-01-01

Constraint Programming is a problem-solving paradigm that establishes a clear distinction between two pivotal aspects of a problem: (1) a precise definition of the constraints that define the problem to be solved and (2) the algorithms and heuristics enabling the selection of decisions to solve the problem. It is because of these capabilities that Constraint Programming is increasingly being employed as a problem-solving tool to solve scheduling problems. Hence the development of Constraint-Based Scheduling as a field of study. The aim of this book is to provide an overview of the most widely used Constraint-Based Scheduling techniques. Following the principles of Constraint Programming, the book consists of three distinct parts: The first chapter introduces the basic principles of Constraint Programming and provides a model of the constraints that are the most often encountered in scheduling problems. Chapters 2, 3, 4, and 5 are focused on the propagation of resource constraints, which usually are responsibl...

Spin glasses and nonlinear constraints in portfolio optimization

International Nuclear Information System (INIS)

Andrecut, M.

2014-01-01

We discuss the portfolio optimization problem with the obligatory deposits constraint. Recently it has been shown that as a consequence of this nonlinear constraint, the solution consists of an exponentially large number of optimal portfolios, completely different from each other, and extremely sensitive to any changes in the input parameters of the problem, making the concept of rational decision making questionable. Here we reformulate the problem using a quadratic obligatory deposits constraint, and we show that from the physics point of view, finding an optimal portfolio amounts to calculating the mean-field magnetizations of a random Ising model with the constraint of a constant magnetization norm. We show that the model reduces to an eigenproblem, with 2N solutions, where N is the number of assets defining the portfolio. Also, in order to illustrate our results, we present a detailed numerical example of a portfolio of several risky common stocks traded on the Nasdaq Market.

Spin glasses and nonlinear constraints in portfolio optimization

Energy Technology Data Exchange (ETDEWEB)

Andrecut, M., E-mail: mircea.andrecut@gmail.com

2014-01-17

We discuss the portfolio optimization problem with the obligatory deposits constraint. Recently it has been shown that as a consequence of this nonlinear constraint, the solution consists of an exponentially large number of optimal portfolios, completely different from each other, and extremely sensitive to any changes in the input parameters of the problem, making the concept of rational decision making questionable. Here we reformulate the problem using a quadratic obligatory deposits constraint, and we show that from the physics point of view, finding an optimal portfolio amounts to calculating the mean-field magnetizations of a random Ising model with the constraint of a constant magnetization norm. We show that the model reduces to an eigenproblem, with 2N solutions, where N is the number of assets defining the portfolio. Also, in order to illustrate our results, we present a detailed numerical example of a portfolio of several risky common stocks traded on the Nasdaq Market.

Geometry and dynamics with time-dependent constraints

CERN Document Server

Evans, Jonathan M.; Jonathan M Evans; Philip A Tuckey

1995-01-01

We describe how geometrical methods can be applied to a system with explicitly time-dependent second-class constraints so as to cast it in Hamiltonian form on its physical phase space. Examples of particular interest are systems which require time-dependent gauge fixing conditions in order to reduce them to their physical degrees of freedom. To illustrate our results we discuss the gauge-fixing of relativistic particles and strings moving in arbitrary background electromagnetic and antisymmetric tensor fields.

Planck intermediate results. XXIV. Constraints on variation of fundamental constants

CERN Document Server

Ade, P A R; Arnaud, M.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Banday, A.J.; Barreiro, R.B.; Battaner, E.; Benabed, K.; Benoit-Levy, A.; Bernard, J.P.; Bersanelli, M.; Bielewicz, P.; Bond, J.R.; Borrill, J.; Bouchet, F.R.; Burigana, C.; Butler, R.C.; Calabrese, E.; Chamballu, A.; Chiang, H.C.; Christensen, P.R.; Clements, D.L.; Colombo, L.P.L.; Couchot, F.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R.D.; Davis, R.J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Diego, J.M.; Dole, H.; Dore, O.; Dupac, X.; Ensslin, T.A.; Eriksen, H.K.; Fabre, O.; Finelli, F.; Forni, O.; Frailis, M.; Franceschi, E.; Galeotta, S.; Galli, S.; Ganga, K.; Giard, M.; Gonzalez-Nuevo, J.; Gorski, K.M.; Gregorio, A.; Gruppuso, A.; Hansen, F.K.; Hanson, D.; Harrison, D.L.; Henrot-Versille, S.; Hernandez-Monteagudo, C.; Herranz, D.; Hildebrandt, S.R.; Hivon, E.; Hobson, M.; Holmes, W.A.; Hornstrup, A.; Hovest, W.; Huffenberger, K.M.; Jaffe, A.H.; Jones, W.C.; Keihanen, E.; Keskitalo, R.; Kneissl, R.; Knoche, J.; Kunz, M.; Kurki-Suonio, H.; Lamarre, J.M.; Lasenby, A.; Lawrence, C.R.; Leonardi, R.; Lesgourgues, J.; Liguori, M.; Lilje, P.B.; Linden-Vornle, M.; Lopez-Caniego, M.; Lubin, P.M.; Macias-Perez, J.F.; Mandolesi, N.; Maris, M.; Martin, P.G.; Martinez-Gonzalez, E.; Masi, S.; Matarrese, S.; Mazzotta, P.; Meinhold, P.R.; Melchiorri, A.; Mendes, L.; Menegoni, E.; Mennella, A.; Migliaccio, M.; Miville-Deschenes, M.A.; Moneti, A.; Montier, L.; Morgante, G.; Moss, A.; Munshi, D.; Murphy, J.A.; Naselsky, P.; Nati, F.; Natoli, P.; Norgaard-Nielsen, H.U.; Noviello, F.; Novikov, D.; Novikov, I.; Oxborrow, C.A.; Pagano, L.; Pajot, F.; Paoletti, D.; Pasian, F.; Patanchon, G.; Perdereau, O.; Perotto, L.; Perrotta, F.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Ponthieu, N.; Popa, L.; Pratt, G.W.; Prunet, S.; Rachen, J.P.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.; Ricciardi, S.; Ristorcelli, I.; Rocha, G.; Roudier, G.; Rusholme, B.; Sandri, M.; Savini, G.; Scott, D.; Spencer, L.D.; Stolyarov, V.; Sudiwala, R.; Sutton, D.; Suur-Uski, A.S.; Sygnet, J.F.; Tauber, J.A.; Tavagnacco, D.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Uzan, J.P.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Vielva, P.; Villa, F.; Wade, L.A.; Yvon, D.; Zacchei, A.; Zonca, A.

2015-01-01

Any variation of the fundamental physical constants, and more particularly of the fine structure constant, $\\alpha$, or of the mass of the electron, $m_e$, would affect the recombination history of the Universe and cause an imprint on the cosmic microwave background angular power spectra. We show that the Planck data allow one to improve the constraint on the time variation of the fine structure constant at redshift $z\\sim 10^3$ by about a factor of 5 compared to WMAP data, as well as to break the degeneracy with the Hubble constant, $H_0$. In addition to $\\alpha$, we can set a constraint on the variation of the mass of the electron, $m_{\\rm e}$, and on the simultaneous variation of the two constants. We examine in detail the degeneracies between fundamental constants and the cosmological parameters, in order to compare the limits obtained from Planck and WMAP and to determine the constraining power gained by including other cosmological probes. We conclude that independent time variations of the fine structu...

On Dirac's conjecture for Hamiltonian systems with first and second class constraints

International Nuclear Information System (INIS)

Cabo, A.; Louis Martinez, D.

1989-07-01

It is shown for a wide class of systems in the framework of the Total Hamiltonian Procedure that all the first class constraints generate canonical transformations connecting physically equivalent states. It occurs whenever the constraints arising in the Dirac algorithm are effective when considered in the functional form as they appear in the consistency conditions. The property of hereditary separation between first and second class constraints also follows from the above condition. General Poisson bracket relations among constraints in the representation used here are also obtained. The sources of anomalies in the hereditary property reported in the literature are identified. (author). 15 refs

On Dirac's conjecture for Hamiltonian systems with first- and second-class constraints

International Nuclear Information System (INIS)

Cabo, A.; Louis-Martinez, D.

1990-01-01

It is shown for a wide class of systems in the framework of the total Hamiltonian procedure that all first-class constraints generate canonical transformations connecting physically equivalent states. It occurs whenever the constraints arising in the Dirac algorithm are effective when considered in the functional form as they appear in the consistency conditions. The property of hereditary separation between first- and second-class constraints also follows from the above condition. General Poisson-brackets relations among constraints in the representation used here are also obtained. The sources of anomalies in the hereditary property reported in the literature are identified

Ring power balance observing plasma stability constraints

International Nuclear Information System (INIS)

Campbell, R.B.; Logan, B.G.

1982-01-01

Ring power balance is performed for an E-ring stabilized tandem mirror reactor, taking into account constraints imposed by plasma stability. The two most important criteria are the stability of the core interchange and hot electron interchange modes. The former determines the ring thickness, the latter determines the minimum hot electron temperature; both quantities are important for power balance. The combination of the hot electron interchange constraint and the fact that the barrier density is low places the operating point on the synchrotron dominated branch of power balance. The reference case considered here requires a reasonable 34 MW of heating power deposited in the rings. We also have examined the sensitivity of the required ring power on uncertainties in the numerical coefficients of the stability constraints. We have found that the heating power is strongly affected

New formulation of Horava-Lifshitz quantum gravity as a master constraint theory

Energy Technology Data Exchange (ETDEWEB)

Soo, Chopin, E-mail: cpsoo@mail.ncku.edu.tw [Department of Physics, National Cheng Kung University, Tainan 70101, Taiwan (China); Yang Jinsong, E-mail: Yangksong@gmail.com [Department of Physics, National Cheng Kung University, Tainan 70101, Taiwan (China); Yu, Hoi-Lai, E-mail: hlyu@phys.sinica.edu.tw [Institute of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwan (China)

2011-07-04

Both projectable and non-projectable versions of Horava-Lifshitz gravity face serious challenges. In the non-projectable version, the constraint algebra is seemingly inconsistent. The projectable version lacks a local Hamiltonian constraint, thus allowing for an extra scalar mode which can be problematic. A new formulation of non-projectable Horava-Lifshitz gravity, naturally realized as a representation of the master constraint algebra studied by loop quantum gravity researchers, is presented. This yields a consistent canonical theory with first class constraints. It captures the essence of Horava-Lifshitz gravity in retaining only spatial diffeomorphisms (instead of full space-time covariance) as the physically relevant non-trivial gauge symmetry; at the same time the local Hamiltonian constraint needed to eliminate the extra mode is equivalently enforced by the master constraint.

Yield stress determination of a physical gel

DEFF Research Database (Denmark)

Hvidt, Søren

2013-01-01

Pluronic F127 solutions form gels in water with high elastic moduli. Pluronic gels can, however, only withstand small deformations and stresses. Different steady shear and oscillatory methods traditionally used to determine yield stress values are compared. The results show that the yield stresses...... values of these gels depend on test type and measurement time, and no absolute yield stress value can be determined for these physical gels....

Data assimilation with inequality constraints

Science.gov (United States)

Thacker, W. C.

If values of variables in a numerical model are limited to specified ranges, these restrictions should be enforced when data are assimilated. The simplest option is to assimilate without regard for constraints and then to correct any violations without worrying about additional corrections implied by correlated errors. This paper addresses the incorporation of inequality constraints into the standard variational framework of optimal interpolation with emphasis on our limited knowledge of the underlying probability distributions. Simple examples involving only two or three variables are used to illustrate graphically how active constraints can be treated as error-free data when background errors obey a truncated multi-normal distribution. Using Lagrange multipliers, the formalism is expanded to encompass the active constraints. Two algorithms are presented, both relying on a solution ignoring the inequality constraints to discover violations to be enforced. While explicitly enforcing a subset can, via correlations, correct the others, pragmatism based on our poor knowledge of the underlying probability distributions suggests the expedient of enforcing them all explicitly to avoid the computationally expensive task of determining the minimum active set. If additional violations are encountered with these solutions, the process can be repeated. Simple examples are used to illustrate the algorithms and to examine the nature of the corrections implied by correlated errors.

Export constraints facing Lesotho-based manufacturing enterprises

Directory of Open Access Journals (Sweden)

Motšelisi C. Mokhethi

2015-07-01

Full Text Available Orientation: Exporting is preferred by many enterprises as the mode of foreign entry as it requires less commitment of organisational resources and offers flexibility of managerial actions. However, enterprises face a number of challenges when attempting to initiate exports or expand their export operations. Research purpose: This study was undertaken to determine the characteristics and composition of export barriers constraining exporting by Lesotho-based manufacturing enterprises. Motivation for the study: Lesotho is faced with low destination diversity and low diversity in export products. Research design, approach and method: Data was collected from 162 Lesotho-based manufacturing enterprises through a self-administered questionnaire. Main findings: In its findings, the study firstly identified international constraints, distribution constraints and financial constraints as factors constraining exporting. Secondly, it was determined that three exporting constraints, all internal to the enterprise and all related to one factor (namely financial constraint hampered exporting. Lastly, the ANOVA results revealed that the perceptions of export constraints differed according to the enterprise characteristics, enterprise size, ownership and type of industry. Contribution/value-add: With the majority of enterprises in this study being identified as micro-enterprises, the government of Lesotho needs to pay particular attention to addressing the export needs of these enterprises in order to enable them to participate in exporting activities − especially considering that they can play a pivotal role in the alleviation of poverty, job creation and economic rejuvenation.

Institutional and resource constraints that inhibit contractor ...

African Journals Online (AJOL)

Results show that contractors face institutional constraints (work allocation limitations, lack of performance incentives and high transaction costs, such as negotiation costs, the risk of a loss in work and contract default risk), cash flow problems, poor physical infrastructure and a lack of labour. It is expected that the promotion ...

Recovery scheduling for industrial pocesses using graph constraints

NARCIS (Netherlands)

Saltik, M.B.; van Gameren, S.; Özkan, L.; Weiland, S.

2017-01-01

This paper considers a class of scheduling problems cast for processes that consist of several interconnected subprocesses. We model the temporal constraints (On-Off status) on each subprocess using labeled directed graphs to form the admissible set of schedules. Furthermore, we consider physical

Determinants of diet and physical activity (DEDIPAC): a summary of findings

NARCIS (Netherlands)

Brug, Johannes; van der Ploeg, Hidde P.; Loyen, Anne; Ahrens, Wolfgang; Allais, Oliver; Andersen, Lene F.; Cardon, Greet; Capranica, Laura; Chastin, Sebastien; de Bourdeaudhuij, Ilse; de Craemer, Marieke; Donnelly, Alan; Ekelund, Ulf; Finglas, Paul; Flechtner-Mors, Marion; Hebestreit, Antje; Kubiak, Thomas; Lanza, Massimo; Lien, Nanna; MacDonncha, Ciaran; Mazzocchi, Mario; Monsivais, Pablo; Murphy, Marie; Nicolaou, Mary; Nöthlings, Ute; O'Gorman, Donal J.; Renner, Britta; Roos, Gun; van den Berg, Matthijs; Schulze, Matthias B.; Steinacker, Jürgen M.; Stronks, Karien; Volkert, Dorothee; Lakerveld, Jeroen

2017-01-01

The establishment of the Determinants of Diet and Physical Activity (DEDIPAC) Knowledge Hub, 2013-2016, was the first action taken by the 'Healthy Diet for a Healthy Life' European Joint Programming Initiative. DEDIPAC aimed to provide better insight into the determinants of diet, physical activity

Determinants of diet and physical activity (DEDIPAC): a summary of findings.

NARCIS (Netherlands)

Brug, Johannes; van der Ploeg, Hidde P; Loyen, Anne; Ahrens, Wolfgang; Allais, Oliver; Andersen, Lene F; Cardon, Greet; Capranica, Laura; Chastin, Sebastien; De Bourdeaudhuij, Ilse; De Craemer, Marieke; Donnelly, Alan; Ekelund, Ulf; Finglas, Paul; Flechtner-Mors, Marion; Hebestreit, Antje; Kubiak, Thomas; Lanza, Massimo; Lien, Nanna; MacDonncha, Ciaran; Mazzocchi, Mario; Monsivais, Pablo; Murphy, Marie; Nicolaou, Mary; Nöthlings, Ute; O'Gorman, Donal J; Renner, Britta; Roos, Gun; van den Berg, Matthijs; Schulze, Matthias B; Steinacker, Jürgen M; Stronks, Karien; Volkert, Dorothee; Lakerveld, Jeroen

2017-01-01

The establishment of the Determinants of Diet and Physical Activity (DEDIPAC) Knowledge Hub, 2013-2016, was the first action taken by the 'Healthy Diet for a Healthy Life' European Joint Programming Initiative. DEDIPAC aimed to provide better insight into the determinants of diet, physical activity

Multiparameter Elastic Full Waveform Inversion With Facies Constraints

KAUST Repository

Zhang, Zhendong

2017-08-17

Full waveform inversion (FWI) aims fully benefit from all the data characteristics to estimate the parameters describing the assumed physics of the subsurface. However, current efforts to utilize full waveform inversion as a tool beyond acoustic imaging applications, for example in reservoir analysis, faces inherent challenges related to the limited resolution and the potential trade-off between the elastic model parameters. Adding rock physics constraints does help to mitigate these issues, but current approaches to add such constraints are based on including them as a priori knowledge mostly valid around the well or as a boundary condition for the whole area. Since certain rock formations inside the Earth admit consistent elastic properties and relative values of elastic and anisotropic parameters (facies), utilizing such localized facies information in FWI can improve the resolution of inverted parameters. We propose a novel confidence map based approach to utilize the facies-based constraints in both isotropic and anisotropic elastic FWI. We invert for such a confidence map using Bayesian theory, in which the confidence map is updated at each iteration of the inversion using both the inverted models and a prior information. The numerical examples show that the proposed method can reduce the trade-offs and also can improve the resolution of the inverted elastic and anisotropic properties.

Determination of the particle size distribution of an aerosol using a diffusion battery

International Nuclear Information System (INIS)

Maigne, Jean-Pierre

1974-02-01

The principal methods for the treatment of concentration measurements both upstream and downstream of a diffusion battery are reviewed and discussed, the purpose of the measurements being the determination of the aerosol particle size distribution. It is then demonstrated that the resolution of the equations arising from the problem leads to the imposing of physical constraints on the distribution sought, these constraints being more and more restrictive with increasing experimental inaccuracies. An algorithm is proposed which provides an approximate solution to the system of equations, certain predetermined criteria, and the constraints imposed on the distribution being taken into account. (author)

Physical constraints on the likelihood of life on exoplanets

Science.gov (United States)

Lingam, Manasvi; Loeb, Abraham

2018-04-01

One of the most fundamental questions in exoplanetology is to determine whether a given planet is habitable. We estimate the relative likelihood of a planet's propensity towards habitability by considering key physical characteristics such as the role of temperature on ecological and evolutionary processes, and atmospheric losses via hydrodynamic escape and stellar wind erosion. From our analysis, we demonstrate that Earth-sized exoplanets in the habitable zone around M-dwarfs seemingly display much lower prospects of being habitable relative to Earth, owing to the higher incident ultraviolet fluxes and closer distances to the host star. We illustrate our results by specifically computing the likelihood (of supporting life) for the recently discovered exoplanets, Proxima b and TRAPPIST-1e, which we find to be several orders of magnitude smaller than that of Earth.

Shaping tissues by balancing active forces and geometric constraints

International Nuclear Information System (INIS)

Foolen, Jasper; Yamashita, Tadahiro; Kollmannsberger, Philip

2016-01-01

The self-organization of cells into complex tissues during growth and regeneration is a combination of physical–mechanical events and biochemical signal processing. Cells actively generate forces at all stages in this process, and according to the laws of mechanics, these forces result in stress fields defined by the geometric boundary conditions of the cell and tissue. The unique ability of cells to translate such force patterns into biochemical information and vice versa sets biological tissues apart from any other material. In this topical review, we summarize the current knowledge and open questions of how forces and geometry act together on scales from the single cell to tissues and organisms, and how their interaction determines biological shape and structure. Starting with a planar surface as the simplest type of geometric constraint, we review literature on how forces during cell spreading and adhesion together with geometric constraints impact cell shape, stress patterns, and the resulting biological response. We then move on to include cell–cell interactions and the role of forces in monolayers and in collective cell migration, and introduce curvature at the transition from flat cell sheets to three-dimensional (3D) tissues. Fibrous 3D environments, as cells experience them in the body, introduce new mechanical boundary conditions and change cell behaviour compared to flat surfaces. Starting from early work on force transmission and collagen remodelling, we discuss recent discoveries on the interaction with geometric constraints and the resulting structure formation and network organization in 3D. Recent literature on two physiological scenarios—embryonic development and bone—is reviewed to demonstrate the role of the force-geometry balance in living organisms. Furthermore, the role of mechanics in pathological scenarios such as cancer is discussed. We conclude by highlighting common physical principles guiding cell mechanics, tissue patterning

Determinants of diet and physical activity (DEDIPAC): a summary of findings

NARCIS (Netherlands)

Brug, J.; van der Ploeg, H.P.; Loyen, A.; Ahrens, W.; Allais, O.; Andersen, L.F.; Cardon, G.; Capranica, L.; Chastin, S.; De Bourdeaudhuij, I.; De Craemer, M.; Donnelly, A.; Ekelund, U.; Finglas, P.; Flechtner-Mors, M.; Hebestreit, A.; Kubiak, T.; Lanza, M.; Lien, N.; MacDonncha, C.; Mazzocchi, M.; Monsivais, P.; Murphy, M.; Nicolaou, M.; Nöthlings, U.; O’Gorman, D.J.; Renner, B.; Roos, G.; van den Berg, M.; Schulze, M.B.; Steinacker, J.M.; Stronks, K.; Volkert, D.; Lakerveld, J.

2017-01-01

The establishment of the Determinants of Diet and Physical Activity (DEDIPAC) Knowledge Hub, 2013–2016, was the first action taken by the ‘Healthy Diet for a Healthy Life’ European Joint Programming Initiative. DEDIPAC aimed to provide better insight into the determinants of diet, physical activity

Self-determination theory and understanding of student motivation in physical education instruction

Directory of Open Access Journals (Sweden)

Đorđić Višnja

2010-01-01

Full Text Available Physical education is considered to be a favorable context for accomplishment of important educational outcomes and promotion of physical activity in children and youth. The real scope of physical education instruction largely depends on student motivation. Self-determination theory, as a specific macrotheory of motivation, offers a rewarding framework for understanding student motivation in physical education instruction. The paper presents the basic tenets of self-determination theory, the most important studies in the domain of physical education and didactic and methodical implications. Two mini-theories within the self-determination theory are analyzed in more detail, the cognitive evaluation theory and the organismic integration theory. Empirical verification of the theoretical tenets indicates the existence of typical motivational profiles of students in physical education instruction, the basic psychological needs as mediators of influence of social and interpersonal factors on student motivation, followed by the importance of motivational climate, students' goal orientations and teaching style for self-determination of students' behavior in physical education instruction. Didactic and methodical implications refer to the need for developing a more flexible curriculum of physical education, encouraging a motivational climate, task-focused goal orientations, and, especially, encouraging the perceived moving competence of the student.

The potential for multi-disciplinary primary health care services to take action on the social determinants of health: actions and constraints.

Science.gov (United States)

Baum, Frances E; Legge, David G; Freeman, Toby; Lawless, Angela; Labonté, Ronald; Jolley, Gwyneth M

2013-05-10

The Commission on the Social Determinants of Health and the World Health Organization have called for action to address the social determinants of health. This paper considers the extent to which primary health care services in Australia are able to respond to this call. We report on interview data from an empirical study of primary health care centres in Adelaide and Alice Springs, Australia. Sixty-eight interviews were held with staff and managers at six case study primary health care services, regional health executives, and departmental funders to explore how their work responded to the social determinants of health and the dilemmas in doing so. The six case study sites included an Aboriginal Community Controlled Organisation, a sexual health non-government organisation, and four services funded and managed by the South Australian government. While respondents varied in the extent to which they exhibited an understanding of social determinants most were reflexive about the constraints on their ability to take action. Services' responses to social determinants included delivering services in a way that takes account of the limitations individuals face from their life circumstances, and physical spaces in the primary health care services being designed to do more than simply deliver services to individuals. The services also undertake advocacy for policies that create healthier communities but note barriers to them doing this work. Our findings suggest that primary health care workers are required to transverse "dilemmatic space" in their work. The absence of systematic supportive policy, frameworks and structure means that it is hard for PHC services to act on the Commission on the Social Determinants of Health's recommendations. Our study does, however, provide evidence of the potential for PHC services to be more responsive to social determinants given more support and by building alliances with communities and social movements. Further research on the value

Performance Determinants in Physical Sciences for ODL ...

African Journals Online (AJOL)

Identifying performance determinants in physical science subjects for students studying through open and distance learning modes in higher learning institutions requires wider range of intuition than it is for conventional institutions. Using data from The Open University of Tanzania, this paper has unearthed some of the ...

Constraint programming and decision making

CERN Document Server

Kreinovich, Vladik

2014-01-01

In many application areas, it is necessary to make effective decisions under constraints. Several area-specific techniques are known for such decision problems; however, because these techniques are area-specific, it is not easy to apply each technique to other applications areas. Cross-fertilization between different application areas is one of the main objectives of the annual International Workshops on Constraint Programming and Decision Making. Those workshops, held in the US (El Paso, Texas), in Europe (Lyon, France), and in Asia (Novosibirsk, Russia), from 2008 to 2012, have attracted researchers and practitioners from all over the world. This volume presents extended versions of selected papers from those workshops. These papers deal with all stages of decision making under constraints: (1) formulating the problem of multi-criteria decision making in precise terms, (2) determining when the corresponding decision problem is algorithmically solvable; (3) finding the corresponding algorithms, and making...

Experimental constraint on quark electric dipole moments

Science.gov (United States)

Liu, Tianbo; Zhao, Zhiwen; Gao, Haiyan

2018-04-01

The electric dipole moments (EDMs) of nucleons are sensitive probes of additional C P violation sources beyond the standard model to account for the baryon number asymmetry of the universe. As a fundamental quantity of the nucleon structure, tensor charge is also a bridge that relates nucleon EDMs to quark EDMs. With a combination of nucleon EDM measurements and tensor charge extractions, we investigate the experimental constraint on quark EDMs, and its sensitivity to C P violation sources from new physics beyond the electroweak scale. We obtain the current limits on quark EDMs as 1.27 ×10-24 e .cm for the up quark and 1.17 ×10-24 e .cm for the down quark at the scale of 4 GeV2 . We also study the impact of future nucleon EDM and tensor charge measurements, and show that upcoming new experiments will improve the constraint on quark EDMs by about 3 orders of magnitude leading to a much more sensitive probe of new physics models.

Modifier constraint in alkali borophosphate glasses using topological constraint theory

Energy Technology Data Exchange (ETDEWEB)

Li, Xiang [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Zeng, Huidan, E-mail: hdzeng@ecust.edu.cn [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Jiang, Qi [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Zhao, Donghui [Unifrax Corporation, Niagara Falls, NY 14305 (United States); Chen, Guorong [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Wang, Zhaofeng; Sun, Luyi [Department of Chemical & Biomolecular Engineering and Polymer Program, Institute of Materials Science, University of Connecticut, Storrs, CT 06269 (United States); Chen, Jianding [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China)

2016-12-01

In recent years, composition-dependent properties of glasses have been successfully predicted using the topological constraint theory. The constraints of the glass network are derived from two main parts: network formers and network modifiers. The constraints of the network formers can be calculated on the basis of the topological structure of the glass. However, the latter cannot be accurately calculated in this way, because of the existing of ionic bonds. In this paper, the constraints of the modifier ions in phosphate glasses were thoroughly investigated using the topological constraint theory. The results show that the constraints of the modifier ions are gradually increased with the addition of alkali oxides. Furthermore, an improved topological constraint theory for borophosphate glasses is proposed by taking the composition-dependent constraints of the network modifiers into consideration. The proposed theory is subsequently evaluated by analyzing the composition dependence of the glass transition temperature in alkali borophosphate glasses. This method is supposed to be extended to other similar glass systems containing alkali ions.

Physical characteristics as determinants of adolescents' moral ...

African Journals Online (AJOL)

This study was designed to investigate the physical characteristics as determinants of adolescent moral behaviour in Ekiti State secondary schools. Two research hypotheses were formulated. The research design used was the descriptive of the survey type. The population for this study was made up of all adolescents in ...

A strong astrophysical constraint on the violation of special relativity by quantum gravity.

Science.gov (United States)

Jacobson, T; Liberati, S; Mattingly, D

2003-08-28

Special relativity asserts that physical phenomena appear the same to all unaccelerated observers. This is called Lorentz symmetry and relates long wavelengths to short ones: if the symmetry is exact it implies that space-time must look the same at all length scales. Several approaches to quantum gravity, however, suggest that there may be a microscopic structure of space-time that leads to a violation of Lorentz symmetry. This might arise because of the discreteness or non-commutivity of space-time, or through the action of extra dimensions. Here we determine a very strong constraint on a type of Lorentz violation that produces a maximum electron speed less than the speed of light. We use the observation of 100-MeV synchrotron radiation from the Crab nebula to improve the previous limit by a factor of 40 million, ruling out this type of Lorentz violation, and thereby providing an important constraint on theories of quantum gravity.

Anthropometric Factors and Physical Condition Dominant Determinants Batting Skills in Softball

Directory of Open Access Journals (Sweden)

Arif Eka Saraya

2018-05-01

Full Text Available batting skills in softball requires several anthropometric factors and physical condition to play to improve skills. Anthropometric factors and physical condition, among others, height, arm length, arm muscle strength, hand-eye coordination, balance, and reaction time. This study aims to determine the anthropometric factors and the physical condition of the dominant determinant of batting skills in softball. This research approach uses a quantitative to design of confirmatory factor analysis. This study population is training student achievement softball in sports education university of riau. A sample of 100 people was obtained through a simple random sampling technique. The data used are taken through a series of tests of the independent and dependent variables. This research method through testing confirmatory factor KMO and Bartlett’s Test analysis using SPSS. Results from this research is: factor of anthropometri dominant physical condition and determinants batting skill in game of softball is arm length with value 0,788, arm muscle power with value 0,851 and time reaction of with value 0,737. The conclusion of this research is: factor of anthropometri dominant physical condition and determinants batting skill in game of softball is arm length, arm muscle power and time reaction

Graphical constraints: a graphical user interface for constraint problems

OpenAIRE

Vieira, Nelson Manuel Marques

2015-01-01

A constraint satisfaction problem is a classical artificial intelligence paradigm characterized by a set of variables (each variable with an associated domain of possible values), and a set of constraints that specify relations among subsets of these variables. Solutions are assignments of values to all variables that satisfy all the constraints. Many real world problems may be modelled by means of constraints. The range of problems that can use this representation is very diverse and embrace...

Primordial black holes survive SN lensing constraints

Science.gov (United States)

García-Bellido, Juan; Clesse, Sébastien; Fleury, Pierre

2018-06-01

It has been claimed in [arxiv:1712.02240] that massive primordial black holes (PBH) cannot constitute all of the dark matter (DM), because their gravitational-lensing imprint on the Hubble diagram of type Ia supernovae (SN) would be incompatible with present observations. In this note, we critically review those constraints and find several caveats on the analysis. First of all, the constraints on the fraction α of PBH in matter seem to be driven by a very restrictive choice of priors on the cosmological parameters. In particular, the degeneracy between Ωm and α was ignored and thus, by fixing Ωm, transferred the constraining power of SN magnitudes to α. Furthermore, by considering more realistic physical sizes for the type-Ia supernovae, we find an effect on the SN lensing magnification distribution that leads to significantly looser constraints. Moreover, considering a wide mass spectrum of PBH, such as a lognormal distribution, further softens the constraints from SN lensing. Finally, we find that the fraction of PBH that could constitute DM today is bounded by fPBH < 1 . 09(1 . 38) , for JLA (Union 2.1) catalogs, and thus it is perfectly compatible with an all-PBH dark matter scenario in the LIGO band.

Gender Performativity in Physics: Affordances or Only Constraints?

Science.gov (United States)

Danielsson, Anna T.; Lundin, Mattias

2014-01-01

In this forum we engage in a dialogue with Allison Gonsalves's paper '"Physics and the girly girl--there is a contradiction somewhere": Doctoral students' positioning around discourses of gender and competence in physics'. In her paper Gonsalves uses a sociocultural approach to examine women doctoral students'…

Wave functions constructed from an invariant sum over histories satisfy constraints

International Nuclear Information System (INIS)

Halliwell, J.J.; Hartle, J.B.

1991-01-01

Invariance of classical equations of motion under a group parametrized by functions of time implies constraints between canonical coordinates and momenta. In the Dirac formulation of quantum mechanics, invariance is normally imposed by demanding that physical wave functions are annihilated by the operator versions of these constraints. In the sum-over-histories quantum mechanics, however, wave functions are specified, directly, by appropriate functional integrals. It therefore becomes an interesting question whether the wave functions so specified obey the operator constraints of the Dirac theory. In this paper, we show for a wide class of theories, including gauge theories, general relativity, and first-quantized string theories, that wave functions constructed from a sum over histories are, in fact, annihilated by the constraints provided that the sum over histories is constructed in a manner which respects the invariance generated by the constraints. By this we mean a sum over histories defined with an invariant action, invariant measure, and an invariant class of paths summed over

Determining the Relationship Between Physical Fitness, Gender, and Life Satisfaction

Directory of Open Access Journals (Sweden)

Kyle Busing

2016-11-01

Full Text Available Previous research has suggested a positive effect of physical activity on life satisfaction. Little research exists that has investigated the relationship between physical fitness and life satisfaction. For this purpose, this research was done to determine the relationship between physical fitness and life satisfaction in a sample of university men and women. Participants (N = 28, Mage = 22.18 completed multiple indicators of physical fitness including cardiovascular fitness, muscular fitness, body composition and flexibility, and life satisfaction (SWLS. Descriptive and one-way between-groups ANOVAs were performed to determine gender differences on measures of life satisfaction and measures of fitness. In addition, the relationship between the five health-related components of fitness and life satisfaction were investigated using Pearson’s product–moment correlation coefficient. Analyses indicated there were no significant correlations between any of the health-related components of fitness and scores on the SWLS. There were significant gender differences on all physical fitness measures, except partial curl-ups, but no significant gender differences on life satisfaction. Our findings suggest that improved physical fitness does not have a relationship with higher life satisfaction measures. Further tests, utilizing larger sample sizes, are recommended.

Physical Activity Motivation: A Practitioner's Guide to Self-Determination Theory.

Science.gov (United States)

Kilpatrick, Marcus; Hebert, Edward; Jacobsen, Dee

2002-01-01

Describes the relationship of self-determination theory to elective physical activity motivation, offering the following recommendations for physical activity practitioners: give positive feedback, promote moderately difficult goals, provide choice of activities, provide a rational for activities, promote the development of social relationships,…

Development and initial validation of the determinants of physical activity questionnaire.

Science.gov (United States)

Taylor, Natalie; Lawton, Rebecca; Conner, Mark

2013-06-11

Physical activity interventions are more likely to be effective if they target causal determinants of behaviour change. Targeting requires accurate identification of specific theoretical determinants of physical activity. Two studies were undertaken to develop and validate the Determinants of Physical Activity Questionnaire. In Study 1, 832 male and female university staff and students were recruited from 49 universities across the UK and completed the 66-item measure, which is based on the Theoretical Domains Framework. Confirmatory factor analysis was undertaken on a calibration sample to generate the model, which resulted in a loss of 31 items. A validation sample was used to cross-validate the model. 20 new items were added and Study 2 tested the revised model in a sample of 466 male and female university students together with a physical activity measure. The final model consisted of 11 factors and 34 items, and CFA produced a reasonable fit χ2 (472) = 852.3, p < .001, CFI = .933, SRMR = .105, RMSEA = .042 (CI = .037-.046), as well as generally acceptable levels of discriminant validity, internal consistency, and test-retest reliability. Eight subscales significantly differentiated between high and low exercisers, indicating that those who exercise less report more barriers for physical activity. A theoretically underpinned measure of determinants of physical activity has been developed with reasonable reliability and validity. Further work is required to test the measure amongst a more representative sample. This study provides an innovative approach to identifying potential barriers to physical activity. This approach illustrates a method for moving from diagnosing implementation difficulties to designing and evaluating interventions.

Influence of the day care, home and neighbourhood environment on young children's physical activity and health

DEFF Research Database (Denmark)

Christian, Hayley; Maitland, Clover; Enkel, Stephanie

2016-01-01

to determine outdoor location of physical activity around the home and neighbourhood for a subsample (n=310). The day care environment will be objectively measured using a validated audit tool. Other potential individual, social and physical environmental influences on preschoolers' physical activity...... such as long day care. Research is required to determine how the design of day care outdoor (and indoor) spaces provides opportunities or constraints for physical activity. A significant evidence gap surrounds what objectively measured attributes of the home and neighbourhood environment influence preschoolers......' physical activity. The PLAY Spaces & Environments for Children's Physical Activity (PLAYCE) study will empirically investigate the relative and cumulative influence of the day care, home and neighbourhood environment on preschoolers' physical activity. METHODS AND ANALYSIS: The PLAYCE study is a cross...

DETERMINATION OF PHYSICAL ACTIVITY DURING SCHOOL RECESS COMBINING MEASUREMENTS OF PHYSICAL ACTIVITY AND CHILDREN’S PERSPECTIVE

Directory of Open Access Journals (Sweden)

Carlos Álvarez Bogantes

2018-01-01

Full Text Available The aim of this study was to determine physical activity levels of children during school recess, taking into account children’s perceptions as well as observations during recess. A mixed method was used, including the System for Observing Play and Leisure Activity in Youth (SOPLAY and focus groups. Participants included students from 3 public schools with regular and alternating schedules, who were observed during their school breaks. In addition, focus groups were held and descriptive statistics were used.  A factorial variance test (2x2 was also used to determine if there were differences between levels of moderate-vigorous physical activity among school types. Results of focus groups were organized into categories. Students exhibited 47.98 sedentary activity and 52.02 moderate-vigorous physical activity during school recess, with girls being more sedentary than boys. Students with an alternating schedule are more active than those with a regular schedule. Participants perceived reduced space to play and little support from teachers as barriers to do physical activity. In conclusion, this study showed that a little over 50% of students perform physical activity during school recess, with children in alternating schedules being more active than those with a regular schedule. Participants perceive that school environment does not favor physical activity, due to environmental barriers. Based on the results of this study, physical activity should be promoted during school recess, taking into consideration barriers in natural, social, physical, and organizational environments.

Constraint theory, singular lagrangians and multitemporal dynamics

International Nuclear Information System (INIS)

Lusanna, L.

1988-01-01

Singular Lagrangians and constraint theory permeate theoretical physics, as shown by the relevance of gauge theories, string models and general relativity. Their study used finite---dimensional models as a guide to develop the theory, but their main use was in classical field theory, due to the necessity of understanding their quantization. The covariant quantization of singular Lagrangians led to the BRST approach and to the theory of the effective action. On the other hand their phase---space formulation, culminated with the BFV approach for first class, second class and reducible constraints. It, in turn, gave new insights in the theory of singular Lagrangians and constraints and in their cohomological aspects. However the Hamiltonian approach to field theory is highly nontrivial, is open to criticism due to its problems with locality, geometry and manifest covariance and its canonical quantization has still to be developed, because there is no proof of the renormalizability of the Schroedinger representation of field theory. This paper discusses how, notwithstanding these developments, there is still a big amount of ambiguity at every level of the theory

Relations among school students' self-determined motivation, perceived enjoyment, effort, and physical activity behaviors.

Science.gov (United States)

Zhang, Tao

2009-12-01

Guided by the self-determination theory, the purpose of this study was to examine the predictive strength of self-determined motivation toward motivational outcomes (perceived enjoyment, perceived effort, physical activity behaviors) for 286 middle school students in physical education. Analyses indicated that intrinsic motivation, identified regulation, and introjected regulation were positively related to students' enjoyment, perceived effort, and physical activity, whereas amotivation was negatively associated with students' enjoyment and perceived effort. The findings highlighted the importance of higher self-determined motivation (intrinsic motivation and identified regulation) in students' perceived enjoyment, effort, and physical activity behaviors. This study supports the use of self-determination theory to investigate students' motivational outcomes in school physical education.

The Determinants of Participation in Physical Activity in Malaysia

Science.gov (United States)

Cheah, Yong Kang; Poh, Bee Koon

2014-01-01

Objectives In light of the importance of physical activity, the aim of the present study is to examine the factors affecting participation in physical activity among adults in Malaysia. Methods A logistic regression model and the Third National Health and Morbidity Survey consisting of 30,992 respondents were used. Results Age, income, gender, education, marital status, region, house locality, job characteristics, and medical conditions are significantly associated with participation in physical activity. In particular, old individuals, high income earners, females, the well-educated, widowed or divorced individuals, East Malaysians, urban dwellers, the unemployed, and individuals who are not diagnosed with hypercholesterolemia are less likely to be physically active than others. Conclusion Because sociodemographic and health factors play an important role in determining physical activity, the government should take them into account when formulating policy. PMID:24955308

Energy constraints and organizational change in US production

Energy Technology Data Exchange (ETDEWEB)

1980-12-01

There is still considerable uncertainty about the way in which energy-supply constraints affect industrial thinking and activity. Yet, this is an important issue in determining the effectiveness of conservation programs and in formulating energy policy. The authors expand on a survey of US business attitudes and responses to energy constraints first published in the September 1979 Energy Policy with the results of further analysis of their survey. In particular, they examine correlations between perceived causes and preferred solutions of energy problems, organizational adjustments to energy constraints in energy-intensive industries, and the ways in which production operations have changed in response to supply problems. 5 references, 5 tables.

Predicting Satisfaction in Physical Education from Motivational Climate and Self-Determined Motivation

Science.gov (United States)

Baena-Extremera, Antonio; Gómez-López, Manuel; Granero-Gallegos, Antonio; Ortiz-Camacho, Maria del Mar

2015-01-01

The purpose of this research study was to determine to what extent the motivational climate perceived by students in Physical Education (PE) classes predicts self-determined motivation, and satisfaction with physical education classes. Questionnaires were administered to 758 high school students aged 13-18 years. We used the Spanish versions of…

DETERMINANTS OF LEISURE-TIME PHYSICAL ACTIVITY: EVIDENCE FROM MALAYSIA

OpenAIRE

YONG KANG CHEAH; ANDREW K. G. TAN

2014-01-01

This paper examines how socio-demographic and health-lifestyle factors determine participation and duration of leisure-time physical activity in Malaysia. Based on the Malaysia Non-Communicable Disease Surveillance-1 data, Heckman's sample selection model is employed to estimate the probability to participate and duration on physical activity. Results indicate that gender, age, years of education and family illness history are significant in explaining participation probability in leisure-tim...

Entropy of Bit-Stuffing-Induced Measures for Two-Dimensional Checkerboard Constraints

DEFF Research Database (Denmark)

Forchhammer, Søren; Vaarby, Torben Strange

2007-01-01

A modified bit-stuffing scheme for two-dimensional (2-D) checkerboard constraints is introduced. The entropy of the scheme is determined based on a probability measure defined by the modified bit-stuffing. Entropy results of the scheme are given for 2-D constraints on a binary alphabet....... The constraints considered are 2-D RLL (d, infinity) for d = 2, 3 and 4 as well as for the constraint with a minimum 1-norm distance of 3 between Is. For these results the entropy is within 1-2% of an upper bound on the capacity for the constraint. As a variation of the scheme, periodic merging arrays are also...

Testing the master constraint programme for loop quantum gravity: V. Interacting field theories

International Nuclear Information System (INIS)

Dittrich, B; Thiemann, T

2006-01-01

This is the fifth and final paper in our series of five in which we test the master constraint programme for solving the Hamiltonian constraint in loop quantum gravity. Here we consider interacting quantum field theories, specifically we consider the non-Abelian Gauss constraints of Einstein-Yang-Mills theory and 2 + 1 gravity. Interestingly, while Yang-Mills theory in 4D is not yet rigorously defined as an ordinary (Wightman) quantum field theory on Minkowski space, in background-independent quantum field theories such as loop quantum gravity (LQG) this might become possible by working in a new, background-independent representation. While for the Gauss constraint the master constraint can be solved explicitly, for the 2 + 1 theory we are only able to rigorously define the master constraint operator. We show that the, by other methods known, physical Hilbert is contained in the kernel of the master constraint, however, to systematically derive it by only using spectral methods is as complicated as for 3 + 1 gravity and we therefore leave the complete analysis for 3 + 1 gravity

Determining energy and climate market policy using multiobjective programs with equilibrium constraints

International Nuclear Information System (INIS)

Siddiqui, Sauleh; Christensen, Adam

2016-01-01

Energy and climate market policy is inherently multiobjective and multilevel, in that desired choices often conflict and are made at a higher level than influenced actors. Analyzing tradeoff between reducing emissions and keeping fuel prices low, while seeking compromise among producers, traders, and consumers is the crux of the policy problem. This paper aims to address this issue by combining multiobjective optimization problems, which allow the study of tradeoff between choices, with equilibrium problems that model the networks and players over which these policies are chosen, to produce a formulation called a Multiobjective Program with Equilibrium Constraints. We apply this formulation to the United States renewable fuel market to help understand why it has been so difficult in releasing the 2014 mandate for the RFS (Renewable Fuel Standard). The RFS ensures that a minimum volume of renewable fuel is included in transportation fuel sold in the United States. Determining the RFS volume requirements involves anticipating market reaction as well as balancing policy objectives. We provide policy alternatives to aid in setting these volume obligations that are applicable to a wide variety of climate and energy market settings and explain why the RFS is not an optimal policy for reducing emissions. - Highlights: • First time a MOPEC has been used to model energy markets and climate policy. • Method to endogenously determine energy policy along with associated tradeoff. • Computationally efficient algorithm for MOPECs and compare to methods. • Explain why the RFS is not an optimal policy for emission reduction.

Cardiovascular risk profile: Cross-sectional analysis of motivational determinants, physical fitness and physical activity

Directory of Open Access Journals (Sweden)

Kiers Henri

2010-10-01

Full Text Available Abstract Background Cardiovascular risk factors are associated with physical fitness and, to a lesser extent, physical activity. Lifestyle interventions directed at enhancing physical fitness in order to decrease the risk of cardiovascular diseases should be extended. To enable the development of effective lifestyle interventions for people with cardiovascular risk factors, we investigated motivational, social-cognitive determinants derived from the Theory of Planned Behavior (TPB and other relevant social psychological theories, next to physical activity and physical fitness. Methods In the cross-sectional Utrecht Police Lifestyle Intervention Fitness and Training (UP-LIFT study, 1298 employees (aged 18 to 62 were asked to complete online questionnaires regarding social-cognitive variables and physical activity. Cardiovascular risk factors and physical fitness (peak VO2 were measured. Results For people with one or more cardiovascular risk factors (78.7% of the total population, social-cognitive variables accounted for 39% (p In addition to the prediction of intention to engage in physical activity and physical active behavior, we explored the impact of the intensity of physical activity. The intentsity of physical activity was only significantly related to physical active behavior (beta = .253, p 2 = .06, p 2 = .23, p For people with one or more cardiovascular risk factors, 39.9% had positive intentions to engage in physical activity and were also physically active, and 10.5% had a low intentions but were physically active. 37.7% had low intentions and were physically inactive, and about 11.9% had high intentions but were physically inactive. Conclusions This study contributes to our ability to optimize cardiovascular risk profiles by demonstrating an important association between physical fitness and social-cognitive variables. Physical fitness can be predicted by physical active behavior as well as by self-efficacy and the intensity of

Resonant spin-flavor precession constraints on the neutrino ...

Indian Academy of Sciences (India)

Home; Journals; Pramana – Journal of Physics; Volume 61; Issue 1. Resonant spin-flavor precession constraints on the neutrino parameters and the twisting structure of the solar magnetic fields from the solar neutrino data. S Dev Jyoti Dhar Sharma U C Pandey S P Sud B C Chauhan. Research Articles Volume 61 Issue 1 ...

Topics in black-hole physics: geometric constraints on noncollapsing, gravitating systems, and tidal distortions of a Schwarzschild black hole

International Nuclear Information System (INIS)

Redmount, I.H.

1984-01-01

This dissertation consists of two studies on the general-relativistic theory of black holes. The first work concerns the fundamental issue of black-hole formation: in it geometric constraints are sought on gravitating matter systems, in the special case of axial symmetry, which determine whether or not those systems undergo gravitational collapse to form black holes. The second project deals with mechanical behavior of a black hole: specifically, the tidal deformation of a static black hole is studied by the gravitational fields of external bodies

Intention and constraints of Hong Kong secondary school Physical ...

African Journals Online (AJOL)

African Journal for Physical Activity and Health Sciences ... of Hong Kong secondary school Physical Education teachers to promote Unified Sports® ... school subjects like Civic Education, Social Studies, Religious Studies or Liberal Studies.

Constraints in distortion-invariant target recognition system simulation

Science.gov (United States)

Iftekharuddin, Khan M.; Razzaque, Md A.

2000-11-01

Automatic target recognition (ATR) is a mature but active research area. In an earlier paper, we proposed a novel ATR approach for recognition of targets varying in fine details, rotation, and translation using a Learning Vector Quantization (LVQ) Neural Network (NN). The proposed approach performed segmentation of multiple objects and the identification of the objects using LVQNN. In this current paper, we extend the previous approach for recognition of targets varying in rotation, translation, scale, and combination of all three distortions. We obtain the analytical results of the system level design to show that the approach performs well with some constraints. The first constraint determines the size of the input images and input filters. The second constraint shows the limits on amount of rotation, translation, and scale of input objects. We present the simulation verification of the constraints using DARPA's Moving and Stationary Target Recognition (MSTAR) images with different depression and pose angles. The simulation results using MSTAR images verify the analytical constraints of the system level design.

Constraint-based reachability

Directory of Open Access Journals (Sweden)

Arnaud Gotlieb

2013-02-01

Full Text Available Iterative imperative programs can be considered as infinite-state systems computing over possibly unbounded domains. Studying reachability in these systems is challenging as it requires to deal with an infinite number of states with standard backward or forward exploration strategies. An approach that we call Constraint-based reachability, is proposed to address reachability problems by exploring program states using a constraint model of the whole program. The keypoint of the approach is to interpret imperative constructions such as conditionals, loops, array and memory manipulations with the fundamental notion of constraint over a computational domain. By combining constraint filtering and abstraction techniques, Constraint-based reachability is able to solve reachability problems which are usually outside the scope of backward or forward exploration strategies. This paper proposes an interpretation of classical filtering consistencies used in Constraint Programming as abstract domain computations, and shows how this approach can be used to produce a constraint solver that efficiently generates solutions for reachability problems that are unsolvable by other approaches.

Constraint-Muse: A Soft-Constraint Based System for Music Therapy

Science.gov (United States)

Hölzl, Matthias; Denker, Grit; Meier, Max; Wirsing, Martin

Monoidal soft constraints are a versatile formalism for specifying and solving multi-criteria optimization problems with dynamically changing user preferences. We have developed a prototype tool for interactive music creation, called Constraint Muse, that uses monoidal soft constraints to ensure that a dynamically generated melody harmonizes with input from other sources. Constraint Muse provides an easy to use interface based on Nintendo Wii controllers and is intended to be used in music therapy for people with Parkinson’s disease and for children with high-functioning autism or Asperger’s syndrome.

Constraints on Alternate Universes: Stars and habitable planets with different fundamental constants

OpenAIRE

Adams, Fred C.

2015-01-01

This paper develops constraints on the values of the fundamental constants that allow universes to be habitable. We focus on the fine structure constant $\\alpha$ and the gravitational structure constant $\\alpha_G$, and find the region in the $\\alpha$-$\\alpha_G$ plane that supports working stars and habitable planets. This work is motivated, in part, by the possibility that different versions of the laws of physics could be realized within other universes. The following constraints are enforce...

Quantifying daily physical activity and determinants in sedentary patients with Parkinson's disease

NARCIS (Netherlands)

Dontje, M. L.; de Greef, M. H. G.; Speelman, A. D.; van Nimwegen, M.; Krijnen, W. P.; Stolk, R. P.; Kamsma, Y. P. T.; Munneke, M.; van der Schans, C. P.; Bloem, Bastiaan R.

2013-01-01

Background: Although physical activity is beneficial for Parkinson's disease (PD) patients, many do not meet the recommended levels. The range of physical activity among sedentary PD patients is unknown, as are factors that determine this variability. Hence, we aimed to (1) assess daily physical

Reduction Of Constraints For Coupled Operations

International Nuclear Information System (INIS)

Raszewski, F.; Edwards, T.

2009-01-01

the High Level Waste (HLW) System Plan. As with the first phase of testing for sludge-only operations, replacement of the homogeneity constraint with the alumina and sum of alkali constraints will ensure acceptable product durability over the compositional region evaluated. Although these study glasses only provide limited data in a large compositional region, the approach and results are consistent with previous studies that challenged the homogeneity constraint for sludge-only operations. That is, minimal benefit is gained by imposing the homogeneity constraint if the other PCCS constraints are satisfied. The normalized boron releases of all of the glasses are well below the Environmental Assessment (EA) glass results, regardless of thermal history. Although one of the glasses had a normalized boron release of approximately 10 g/L and was not predictable, the glass is still considered acceptable. This particular glass has a low Al 2 O 3 concentration, which may have attributed to the anomalous behavior. Given that poor durability has been previously observed in other glasses with low Al 2 O 3 and Fe 2 O 3 concentrations, including the sludge-only reduction of constraints study, further investigations appear to be warranted. Based on the results of this study, it is recommended that the homogeneity constraint (in its entirety with the associated low frit/high frit constraints) be eliminated for coupled operations as defined by Revision 14 of the HLW System Plan with up to 2 wt% TiO 2 . The use of the alumina and sum of alkali constraints should be continued along with the variability study to determine the predictability of the current durability models and/or that the glasses are acceptable with respect to durability. The use of a variability study for each batch is consistent with the glass product control program and it will help to assess new streams or compositional changes. It is also recommended that the influence of alumina and alkali on durability be studied

Constraints on Non-Standard Contributions to the Charged-Current Interactions

CERN Document Server

Hagiwara, K; Hagiwara, Kaoru; Matsumoto, Seiji

1998-01-01

The success of the quantum level predictions of the Standard Model on the $Z$ boson properties, on $\\mw$ and on $\\mt$, which makes use of the muon lifetime as an input, implies a stringent constraint on new physics contributions to the $V-A$ charged-current interactions among leptons. Observed unitarity of the CKM matrix elements then implies constraints on non-standard contributions to the lepton-quark charged-current interactions. By using the recent electroweak data as inputs, we find the 95% CL limits for the corresponding contact interactions: $\\Lambda_{CC,+}^{\\ell\\ell}>7.5$ TeV and the lepton-quark contact interactions.

Access Constraints Experienced by Physically Disabled Students at a South African Higher Education Institution

Science.gov (United States)

Engelbrecht, L.; de Beer, J. J.

2014-01-01

Current developments in government law and policies have created the hope that people living with a disability will enjoy the same rights and privileges as the non-disabled. Unfortunately, only 2.8% of disabled persons have access to higher education. The aim of this study was to determine if a group of students, living with a physical disability,…

Physical activity levels and determinants of change in young adults: a longitudinal panel study

OpenAIRE

Zimmermann Erwin; Wanner Miriam; Zimmermann-Sloutskis Dorith; Martin Brian W

2010-01-01

Abstract Background There is growing concern about physical inactivity in adolescents and young adults. Identifying determinants that are associated with low levels of physical activity and with changes in physical activity levels will help to develop specific prevention strategies. The present study describes the prevalence and potential determinants of physical activity behavior and behavior changes of young adults. The study is based on the Swiss Household Panel (SHP), a longitudinal study...

Locality constraints and 2D quasicrystals

International Nuclear Information System (INIS)

Socolar, J.E.S.

1990-01-01

The plausible assumption that long-range interactions between atoms are negligible in a quasicrystal leaks to the study of tilings that obey constraints on the local configurations of tiles. The theory of such constraints (called matching rules) for 2D quasicrystal tilings is reviewed here. Different types of matching rules are defined and examples of tilings obeying them are given where known. The role of tile decoration is discussed and is shown to be significant in at least two cases (octagonal and dodecagonal duals of periodic 4-grids and 6-grids). A new result is introduced: a constructive procedure is described for generating weak matching rules for tilings with N-fold symmetry, for any N that is either a prime number or twice a prime number. The physics associated with weak matching rules, results on local growth rules, and the case of icosahedral symmetry are all briefly discussed. (author). 29 refs, 4 figs

Accelerometer-determined physical activity level among government employees in Penang, Malaysia.

Science.gov (United States)

Hazizi, A S; Aina, Mardiah B; Mohd, Nasir M T; Zaitun, Y; Hamid, Jan J M; Tabata, I

2012-04-01

A cross-sectional study was carried out to investigate accelerometer-determined physical activity level of 233 Malay government employees (104 men, 129 women) working in the Federal Government Building Penang, Malaysia. Body weight, height, waist and hip circumference, body fat percentage and blood pressure were measured for each respondent. All the respondents were asked to wear an accelerometer for 3 days. Body mass index (BMI) and waist-hip ratio (WHR) were calculated using a standard formulas. Fasting blood sample was obtained to determine the lipid profile and glucose levels of the respondents. Based on the accelerometer-determined physical activity level, almost 65% of the respondents were categorised as sedentary. Approximately 50.2% of the respondents were overweight or obese. There were negative but significant relationships between body mass index (BMI) (r = -0.353, p obesity in this study. The high prevalence of physical inactivity and obesity found among respondents of this study indicate a need for implementing intervention programmes among this population.

Modeling Global Ocean Biogeochemistry With Physical Data Assimilation: A Pragmatic Solution to the Equatorial Instability

Science.gov (United States)

Park, Jong-Yeon; Stock, Charles A.; Yang, Xiaosong; Dunne, John P.; Rosati, Anthony; John, Jasmin; Zhang, Shaoqing

2018-03-01

Reliable estimates of historical and current biogeochemistry are essential for understanding past ecosystem variability and predicting future changes. Efforts to translate improved physical ocean state estimates into improved biogeochemical estimates, however, are hindered by high biogeochemical sensitivity to transient momentum imbalances that arise during physical data assimilation. Most notably, the breakdown of geostrophic constraints on data assimilation in equatorial regions can lead to spurious upwelling, resulting in excessive equatorial productivity and biogeochemical fluxes. This hampers efforts to understand and predict the biogeochemical consequences of El Niño and La Niña. We develop a strategy to robustly integrate an ocean biogeochemical model with an ensemble coupled-climate data assimilation system used for seasonal to decadal global climate prediction. Addressing spurious vertical velocities requires two steps. First, we find that tightening constraints on atmospheric data assimilation maintains a better equatorial wind stress and pressure gradient balance. This reduces spurious vertical velocities, but those remaining still produce substantial biogeochemical biases. The remainder is addressed by imposing stricter fidelity to model dynamics over data constraints near the equator. We determine an optimal choice of model-data weights that removed spurious biogeochemical signals while benefitting from off-equatorial constraints that still substantially improve equatorial physical ocean simulations. Compared to the unconstrained control run, the optimally constrained model reduces equatorial biogeochemical biases and markedly improves the equatorial subsurface nitrate concentrations and hypoxic area. The pragmatic approach described herein offers a means of advancing earth system prediction in parallel with continued data assimilation advances aimed at fully considering equatorial data constraints.

Perceived Teaching Behaviors and Self-Determined Motivation in Physical Education: A Test of Self-Determination Theory

Science.gov (United States)

Koka, Andre; Hagger, Martin S.

2010-01-01

In the present study, we tested the effects of specific dimensions of perceived teaching behaviors on students' self-determined motivation in physical education. In accordance with the tenets of self-determination theory (Deci & Ryan, 1985, 2000), we expected the psychological needs for competence, autonomy, and relatedness would mediate these…

Impact mitigation using kinematic constraints and the full space parameterization method

Energy Technology Data Exchange (ETDEWEB)

Morgansen, K.A.; Pin, F.G.

1996-02-01

A new method for mitigating unexpected impact of a redundant manipulator with an object in its environment is presented. Kinematic constraints are utilized with the recently developed method known as Full Space Parameterization (FSP). System performance criterion and constraints are changed at impact to return the end effector to the point of impact and halt the arm. Since large joint accelerations could occur as the manipulator is halted, joint acceleration bounds are imposed to simulate physical actuator limitations. Simulation results are presented for the case of a simple redundant planar manipulator.

Experimental Status of B Physics

International Nuclear Information System (INIS)

Stone, Sheldon

2006-01-01

A short summary is given of the current status of B physics. Reasons for physics beyond the Standard Model are discussed. Constraints on New Physics are given using measurements of B mixing, BS mixing, and CP violation, along with |Vub|. Future goals, and upcoming new experiments are also mentioned

Standard Model updates and new physics analysis with the Unitarity Triangle fit

International Nuclear Information System (INIS)

Bevan, A.; Bona, M.; Ciuchini, M.; Derkach, D.; Franco, E.; Silvestrini, L.; Lubicz, V.; Tarantino, C.; Martinelli, G.; Parodi, F.; Schiavi, C.; Pierini, M.; Sordini, V.; Stocchi, A.; Vagnoni, V.

2013-01-01

We present the summer 2012 update of the Unitarity Triangle (UT) analysis performed by the UTfit Collaboration within the Standard Model (SM) and beyond. The increased accuracy on several of the fundamental constraints is now enhancing some of the tensions amongst and within the constraint themselves. In particular, the long standing tension between exclusive and inclusive determinations of the V ub and V cb CKM matrix elements is now playing a major role. Then we present the generalisation the UT analysis to investigate new physics (NP) effects, updating the constraints on NP contributions to ΔF=2 processes. In the NP analysis, both CKM and NP parameters are fitted simultaneously to obtain the possible NP effects in any specific sector. Finally, based on the NP constraints, we derive upper bounds on the coefficients of the most general ΔF=2 effective Hamiltonian. These upper bounds can be translated into lower bounds on the scale of NP that contributes to these low-energy effective interactions

Determinants of diet and physical activity (DEDIPAC): a summary of findings.

Science.gov (United States)

Brug, Johannes; van der Ploeg, Hidde P; Loyen, Anne; Ahrens, Wolfgang; Allais, Oliver; Andersen, Lene F; Cardon, Greet; Capranica, Laura; Chastin, Sebastien; De Bourdeaudhuij, Ilse; De Craemer, Marieke; Donnelly, Alan; Ekelund, Ulf; Finglas, Paul; Flechtner-Mors, Marion; Hebestreit, Antje; Kubiak, Thomas; Lanza, Massimo; Lien, Nanna; MacDonncha, Ciaran; Mazzocchi, Mario; Monsivais, Pablo; Murphy, Marie; Nicolaou, Mary; Nöthlings, Ute; O'Gorman, Donal J; Renner, Britta; Roos, Gun; van den Berg, Matthijs; Schulze, Matthias B; Steinacker, Jürgen M; Stronks, Karien; Volkert, Dorothee; Lakerveld, Jeroen

2017-11-03

The establishment of the Determinants of Diet and Physical Activity (DEDIPAC) Knowledge Hub, 2013-2016, was the first action taken by the 'Healthy Diet for a Healthy Life' European Joint Programming Initiative. DEDIPAC aimed to provide better insight into the determinants of diet, physical activity and sedentary behaviour across the life course, i.e. insight into the causes of the causes of important, non-communicable diseases across Europe and beyond. DEDIPAC was launched in late 2013, and delivered its final report in late 2016. In this paper we give an overview of what was achieved in terms of furthering measurement and monitoring, providing overviews of the state-of-the-art in the field, and building toolboxes for further research and practice. Additionally, we propose some of the next steps that are now required to move forward in this field, arguing in favour of 1) sustaining the Knowledge Hub and developing it into a European virtual research institute and knowledge centre for determinants of behavioural nutrition and physical activity with close links to other parts of the world; 2) establishing a cohort study of families across all regions of Europe focusing specifically on the individual and contextual determinants of major, non-communicable disease; and 3) furthering DEDIPAC's work on nutrition, physical activity, and sedentary behaviour policy evaluation and benchmarking across Europe by aligning with other international initiatives and by supporting harmonisation of pan-European surveillance.

Determining the constraints and challenges of vermicompost technology development: the case of active sites in Kermanshah Province

Directory of Open Access Journals (Sweden)

mariyeh sahraie

2015-11-01

Full Text Available Entrepreneurial enterprises have the potential to create new business opportunities and provide alternative income sources for rural populations. Vermicompost production provides diversified income for farmers using livestock manure as well as agricultural residues and household wastes. The economic, social, cultural, and environmental importance of vermicompost technology has made it a unique opportunity for rural households to maintain food security and sustainable livelihood. However, this technology has not yet been diffused across rural population in the Kermanshah Province. Therefore, the purpose of this design was to determine the constraints and challenges of vermicompost technology development in the case of active sites in the Kermanshah Province by using a qualitative study and a well-established theoretical approach. The population for this study comprised of all vermicompost producers in the Kermanshah province (N=52. A purposeful sample of 21 producers with a minimum of two years of experience in vermicompost production participated in the study. Data was collected using deep and semi-structured interviews. Open, axial, and selective coding was used to analyze the data. The results revealed that the following constraints and challenges impede the development of vermicompost technology: low production during the winter, high prices for the customers, lack of technical and marketing skills among the producers, lack of efficient support and monitoring, weak adoption process due to cultural beliefs, and inefficient extension and diffusion by public institutions.

Search for signals of new physics in particle physics and cosmology

International Nuclear Information System (INIS)

Virey, J.M.

2007-12-01

The author reviews his contributions in particle physics and cosmology. The first part is dedicated to the study of non standard signals collected in particle collisions. It is shown that a pure hadronic interaction, weak compared with QCD, can stay un-observed and be detected only by studying spin asymmetries. He has also studied important and unique information carried by these spin asymmetries on the chiral structure and scalar structure of new interactions. The models describing this new physics appear as low energy applications of more general models concerning sub-structures or great unification, or more specific models in supersymmetry or string theory. As an illustration he presents a study of the features of supersymmetry in cases where the R-parity is broken. The second part is dedicated to the study of cosmological parameters and particularly of the properties of black energy. It is shown that assumptions on the characteristics of the black energy have a great impact on the determination of other parameters when interpreting experimental data. Another point is the determination of constraints on the black energy from the analysis of observation data

Self-determined motivation and students' physical activity during structured physical education lessons and free choice periods.

Science.gov (United States)

Lonsdale, Chris; Sabiston, Catherine M; Raedeke, Thomas D; Ha, Amy S C; Sum, Raymond K W

2009-01-01

Various organizations have suggested that physical education (PE) should play a central role in increasing adolescents' physical activity (PA) levels. The purpose of this study was to examine relationships between students' self-determined motivation and their PA behavior during a structured PE lesson led by their teacher and a free-choice period in which they were not required to be active. 528 Hong Kong students (mean age=15.78 years) participated in this study in April and May 2007. Situational Motivation Scale scores were used to form high and low self-determined motivation groups. Students wore a pedometer during a 20-minute structured basketball lesson and a 20-minute free choice period, during which they did not receive instruction. ANOVA revealed that self-determined motivation and PE class environments which provided students opportunities to make choices were related to greater PA. Furthermore, the difference in PA between the high and low self-determined groups was greater in the free-choice condition than the structured lesson, suggesting that self-determined motivation is especially important when students are not supervised. Findings indicated that promoting self-determined motivation may be an effective means of ensuring that PE programs are able to increase PA levels, foster self-initiated PA behaviors, and enhance adolescents' health.

Physical Attractiveness, Age, and Sex as Determinants of Reactions to Resumes.

Science.gov (United States)

Quereshi, M. Y.; Kay, Janet P.

1986-01-01

Physical attractiveness, age, and sex were manipulated to determine their effect on the evaluation of 54 hypothetical applicants' resumes for three different jobs by 60 Master's in Business Administration students. Physical attractiveness favorably influenced the suitability ratings for all jobs; raters' sex and age were not significant but…

Determinants of Dutch general practitioners’ nutrition and physical activity guidance practices

NARCIS (Netherlands)

Hiddink, G.J.; Woerkum, van C.M.J.; Dillen, van S.M.E.

2013-01-01

Objective General practitioners (GP) are uniquely placed to guide their patients on nutrition and physical activity. The aims of the present study were to assess: (i) the extent to which GP guide on nutrition and physical activity; (ii) the determinants that cause GP to give guidance on nutrition

New constraints for canonical general relativity

International Nuclear Information System (INIS)

Reisenberger, M.P.

1995-01-01

Ashtekar's canonical theory of classical complex Euclidean GR (no Lorentzian reality conditions) is found to be invariant under the full algebra of infinitesimal 4-diffeomorphisms, but non-invariant under some finite proper 4-diffeos when the densitized dreibein, E a i , is degenerate. The breakdown of 4-diffeo invariance appears to be due to the inability of the Ashtekar Hamiltonian to generate births and deaths of E flux loops (leaving open the possibility that a new 'causality condition' forbidding the birth of flux loops might justify the non-invariance of the theory).A fully 4-diffeo invariant canonical theory in Ashtekar's variables, derived from Plebanski's action, is found to have constraints that are stronger than Ashtekar's for rank E< 2. The corresponding Hamiltonian generates births and deaths of E flux loops.It is argued that this implies a finite amplitude for births and deaths of loops in the physical states of quantum GR in the loop representation, thus modifying this (partly defined) theory substantially.Some of the new constraints are second class, leading to difficulties in quantization in the connection representation. This problem might be overcome in a very nice way by transforming to the classical loop variables, or the 'Faraday line' variables of Newman and Rovelli, and then solving the offending constraints.Note that, though motivated by quantum considerations, the present paper is classical in substance. (orig.)

Momentum constraint relaxation

International Nuclear Information System (INIS)

Marronetti, Pedro

2006-01-01

Full relativistic simulations in three dimensions invariably develop runaway modes that grow exponentially and are accompanied by violations of the Hamiltonian and momentum constraints. Recently, we introduced a numerical method (Hamiltonian relaxation) that greatly reduces the Hamiltonian constraint violation and helps improve the quality of the numerical model. We present here a method that controls the violation of the momentum constraint. The method is based on the addition of a longitudinal component to the traceless extrinsic curvature A ij -tilde, generated by a vector potential w i , as outlined by York. The components of w i are relaxed to solve approximately the momentum constraint equations, slowly pushing the evolution towards the space of solutions of the constraint equations. We test this method with simulations of binary neutron stars in circular orbits and show that it effectively controls the growth of the aforementioned violations. We also show that a full numerical enforcement of the constraints, as opposed to the gentle correction of the momentum relaxation scheme, results in the development of instabilities that stop the runs shortly

A theoretical approach to the problem of dose-volume constraint estimation and their impact on the dose-volume histogram selection

International Nuclear Information System (INIS)

Schinkel, Colleen; Stavrev, Pavel; Stavreva, Nadia; Fallone, B. Gino

2006-01-01

This paper outlines a theoretical approach to the problem of estimating and choosing dose-volume constraints. Following this approach, a method of choosing dose-volume constraints based on biological criteria is proposed. This method is called ''reverse normal tissue complication probability (NTCP) mapping into dose-volume space'' and may be used as a general guidance to the problem of dose-volume constraint estimation. Dose-volume histograms (DVHs) are randomly simulated, and those resulting in clinically acceptable levels of complication, such as NTCP of 5±0.5%, are selected and averaged producing a mean DVH that is proven to result in the same level of NTCP. The points from the averaged DVH are proposed to serve as physical dose-volume constraints. The population-based critical volume and Lyman NTCP models with parameter sets taken from literature sources were used for the NTCP estimation. The impact of the prescribed value of the maximum dose to the organ, D max , on the averaged DVH and the dose-volume constraint points is investigated. Constraint points for 16 organs are calculated. The impact of the number of constraints to be fulfilled based on the likelihood that a DVH satisfying them will result in an acceptable NTCP is also investigated. It is theoretically proven that the radiation treatment optimization based on physical objective functions can sufficiently well restrict the dose to the organs at risk, resulting in sufficiently low NTCP values through the employment of several appropriate dose-volume constraints. At the same time, the pure physical approach to optimization is self-restrictive due to the preassignment of acceptable NTCP levels thus excluding possible better solutions to the problem

Physical, Psychological and Emotional Benefits of Green Physical Activity: An Ecological Dynamics Perspective.

Science.gov (United States)

Yeh, Hsiao-Pu; Stone, Joseph Antony; Churchill, Sarah May; Wheat, Jonathan Stephen; Brymer, Eric; Davids, Keith

2016-07-01

Increasing evidence supports the multiple benefits to physical, psychological and emotional wellbeing of green physical activity, a topic of increasing interest in the past decade. Research has revealed a synergistic benefit of green physical activity, which includes all aspects of exercise and physical activity in the presence of nature. Our theoretical analysis suggests there are three distinct levels of engagement in green physical activity, with each level reported to have a positive effect on human behaviours. However, the extent to which each level of green physical activity benefits health and wellbeing is assumed to differ, requiring confirmation in future research. This elucidation of understanding is needed because previous literature has tended to focus on recording empirical evidence rather than developing a sound theoretical framework to understand green physical activity effects. Here we propose an ecological dynamics rationale to explain how and why green physical activity might influence health and wellbeing of different population groups. This framework suggests a number of unexplored, interacting constraints related to types of environment and population groups, which shape reported levels of benefit of green physical activity. Further analysis is needed to clarify the explicit relationship between green physical activity and health and wellbeing, including levels of engagement, types of environmental constraints, levels of physical activity, adventure effects, skill effects and sampling of different populations.

Quantization of 2 + 1-spinning particles and bifermionic constraint problem

Energy Technology Data Exchange (ETDEWEB)

Fresneda, R.; Gavrilov, S.P.; Gitman, D.M.; Moshin, P.Yu. [Sao Paulo Univ., SP (Brazil). Inst. de Fisica

2004-07-01

In this paper, we have quantized a P- and T-noninvariant pseudoclassical model of a massive relativistic spin-1=2 particle in 2 + 1 dimensions, on the background of an arbitrary U(1) gauge vector field. A peculiar feature of the model at the classical level is that it contains a bifermionic first-class constraint, which does not admit gauge-fixing. It is shown that this first-class constraint can be realized at the quantum level as a bounded operator, which is imposed as a condition on the state vectors (by analogy with the Dirac quantization method). This allows us to generalize the quantization scheme [?] in case there is a bifermionic first-class constraint.We present a detailed construction of the Hilbert space and verify that the constructed QM possesses the necessary symmetry properties. We show that the condition of preservation of the classical symmetries under the restricted Lorentz transformations and the U(1) transformations allows one to realize the operator algebra in an unambiguous way. Within the constructed relativistic QM, we select a physical subspace which describes the one-particle sector. The physical sector of the QM contains both particles and antiparticles with positive energy hat {omega} levels, and exactly reproduces the one-particle sector of the quantum theory of the 2 + 1 spinor field. (author)

Cardiovascular risk profile: cross-sectional analysis of motivational determinants, physical fitness and physical activity.

Science.gov (United States)

Sassen, Barbara; Kok, Gerjo; Schaalma, Herman; Kiers, Henri; Vanhees, Luc

2010-10-07

Cardiovascular risk factors are associated with physical fitness and, to a lesser extent, physical activity. Lifestyle interventions directed at enhancing physical fitness in order to decrease the risk of cardiovascular diseases should be extended. To enable the development of effective lifestyle interventions for people with cardiovascular risk factors, we investigated motivational, social-cognitive determinants derived from the Theory of Planned Behavior (TPB) and other relevant social psychological theories, next to physical activity and physical fitness. In the cross-sectional Utrecht Police Lifestyle Intervention Fitness and Training (UP-LIFT) study, 1298 employees (aged 18 to 62) were asked to complete online questionnaires regarding social-cognitive variables and physical activity. Cardiovascular risk factors and physical fitness (peak VO2) were measured. For people with one or more cardiovascular risk factors (78.7% of the total population), social-cognitive variables accounted for 39% (p < .001) of the variance in the intention to engage in physical activity for 60 minutes every day. Important correlates of intention to engage in physical activity were attitude (beta = .225, p < .001), self-efficacy (beta = .271, p < .001), descriptive norm (beta = .172, p < .001) and barriers (beta = -.169, p < .01). Social-cognitive variables accounted for 52% (p < .001) of the variance in physical active behaviour (being physical active for 60 minutes every day). The intention to engage in physical activity (beta = .469, p < .001) and self-efficacy (beta = .243, p < .001) were, in turn, important correlates of physical active behavior.In addition to the prediction of intention to engage in physical activity and physical active behavior, we explored the impact of the intensity of physical activity. The intensity of physical activity was only significantly related to physical active behavior (beta = .253, p < .01, R2 = .06, p < .001). An important goal of our study was to

HOROPLAN: computer-assisted nurse scheduling using constraint-based programming.

Science.gov (United States)

Darmoni, S J; Fajner, A; Mahé, N; Leforestier, A; Vondracek, M; Stelian, O; Baldenweck, M

1995-01-01

Nurse scheduling is a difficult and time consuming task. The schedule has to determine the day to day shift assignments of each nurse for a specified period of time in a way that satisfies the given requirements as much as possible, taking into account the wishes of nurses as closely as possible. This paper presents a constraint-based, artificial intelligence approach by describing a prototype implementation developed with the Charme language and the first results of its use in the Rouen University Hospital. Horoplan implements a non-cyclical constraint-based scheduling, using some heuristics. Four levels of constraints were defined to give a maximum of flexibility: French level (e.g. number of worked hours in a year), hospital level (e.g. specific day-off), department level (e.g. specific shift) and care unit level (e.g. specific pattern for week-ends). Some constraints must always be verified and can not be overruled and some constraints can be overruled at a certain cost. Rescheduling is possible at any time specially in case of an unscheduled absence.

Determinants of physical activity in primary school students using the health belief model.

Science.gov (United States)

Ar-Yuwat, Sireewat; Clark, Mary Jo; Hunter, Anita; James, Kathy S

2013-01-01

Thailand is a middle-income country in which two-thirds of children demonstrate an insufficient level of physical activity. Physical inactivity is a major risk factor for obesity and many other health-related consequences in children. Thus, it is important to understand how primary school children perceive things in their daily life as determinants of physical activity. The purpose of this study was to investigate the impact of cues, perceived benefits, and perceived barriers on the level of physical activity among primary school students. A cross-sectional study was conducted in Phitsanulok Province, Thailand, in 2011. Multistage sampling selected a total of 123 primary school students. The Physical Activity Questionnaire for Older Children and the Cues, Perceived Benefits, and Barriers to Physical Activity Questionnaire were used to assess the student levels of physical activity, as well as the perceived benefits, barriers, and cues to action. The association between these factors and the level of physical activity was determined by correlation statistics and confirmed by robust regression. Multivariate analysis of variance compared health belief model determinants: perceived benefits, perceived barriers, and cues to action on physical activity between male and female students. Self-administered questionnaires were validated and tested in a pilot study. The level of activity among primary school children was significantly influenced by perceived barriers, such as fear of strangers when playing outdoors, bad weather, and too much homework. However, activity was not influenced by cues to action or perceived benefits. Perceived benefits, barriers, and cues to physical activity did not differ by gender. A safe environment and fewer barriers, such as amount of homework, could enhance physical activity in primary school children.

Computing group cardinality constraint solutions for logistic regression problems.

Science.gov (United States)

Zhang, Yong; Kwon, Dongjin; Pohl, Kilian M

2017-01-01

We derive an algorithm to directly solve logistic regression based on cardinality constraint, group sparsity and use it to classify intra-subject MRI sequences (e.g. cine MRIs) of healthy from diseased subjects. Group cardinality constraint models are often applied to medical images in order to avoid overfitting of the classifier to the training data. Solutions within these models are generally determined by relaxing the cardinality constraint to a weighted feature selection scheme. However, these solutions relate to the original sparse problem only under specific assumptions, which generally do not hold for medical image applications. In addition, inferring clinical meaning from features weighted by a classifier is an ongoing topic of discussion. Avoiding weighing features, we propose to directly solve the group cardinality constraint logistic regression problem by generalizing the Penalty Decomposition method. To do so, we assume that an intra-subject series of images represents repeated samples of the same disease patterns. We model this assumption by combining series of measurements created by a feature across time into a single group. Our algorithm then derives a solution within that model by decoupling the minimization of the logistic regression function from enforcing the group sparsity constraint. The minimum to the smooth and convex logistic regression problem is determined via gradient descent while we derive a closed form solution for finding a sparse approximation of that minimum. We apply our method to cine MRI of 38 healthy controls and 44 adult patients that received reconstructive surgery of Tetralogy of Fallot (TOF) during infancy. Our method correctly identifies regions impacted by TOF and generally obtains statistically significant higher classification accuracy than alternative solutions to this model, i.e., ones relaxing group cardinality constraints. Copyright © 2016 Elsevier B.V. All rights reserved.

Self-determined motivation in physical education and its links to motivation for leisure-time physical activity, physical activity, and well-being in general.

Science.gov (United States)

Bagøien, Tor Egil; Halvari, Hallgeir; Nesheim, Hallgeir

2010-10-01

The present study tested a trans-contextual model based on self-determination theory of the relations between motivation in physical education, motivation in leisure-time physical activity, physical activity, and psychological well-being. Participants were 329 Norwegian upper secondary school students (M age = 16.5 yr., SD = 0.7). Students' perceptions of autonomy-supportive teachers in physical education were expected to be positively associated with students' psychological needs satisfaction in physical education, which was expected to be positively related to autonomous motivation for physical education participation. In turn, autonomous motivation for physical education was expected to be positively associated with perceived competence and autonomous motivation for leisure-time physical activity, which both were expected to be positively associated with leisure-time physical activity and psychological well-being in general. Structural equation models and bootstrapping supported the hypotheses and the indirect links between variables. Sex differences indicate that more research is needed on how to motivate girls to be more physically active in leisure time.

Capturing the complex behavior of hydraulic fracture stimulation through multi-physics modeling, field-based constraints, and model reduction

Science.gov (United States)

Johnson, S.; Chiaramonte, L.; Cruz, L.; Izadi, G.

2016-12-01

Advances in the accuracy and fidelity of numerical methods have significantly improved our understanding of coupled processes in unconventional reservoirs. However, such multi-physics models are typically characterized by many parameters and require exceptional computational resources to evaluate systems of practical importance, making these models difficult to use for field analyses or uncertainty quantification. One approach to remove these limitations is through targeted complexity reduction and field data constrained parameterization. For the latter, a variety of field data streams may be available to engineers and asset teams, including micro-seismicity from proximate sites, well logs, and 3D surveys, which can constrain possible states of the reservoir as well as the distributions of parameters. We describe one such workflow, using the Argos multi-physics code and requisite geomechanical analysis to parameterize the underlying models. We illustrate with a field study involving a constraint analysis of various field data and details of the numerical optimizations and model reduction to demonstrate how complex models can be applied to operation design in hydraulic fracturing operations, including selection of controllable completion and fluid injection design properties. The implication of this work is that numerical methods are mature and computationally tractable enough to enable complex engineering analysis and deterministic field estimates and to advance research into stochastic analyses for uncertainty quantification and value of information applications.

constraints of micro hydroelectric power plants in the west region of ...

African Journals Online (AJOL)

DJFLEX

KEYWORDS: Constraints; craftsmen; funds; highlands; hydroelectric. INTRODUCTION ... MATERIAL AND METHODS. 1.1 Physical ... (Bamougoum; Bapi; Batotcha) are due to the use ... water very often escapes from the air vent because of its .... The funds raised will remedy ... Graw-Hill Book Company New York,. USA.

Electric dipole moments as probes of new physics

CERN Document Server

Pospelov, M; Pospelov, Maxim; Ritz, Adam

2005-01-01

We review several aspects of flavour-diagonal CP violation, focussing on the role played by the electric dipole moments (EDMs) of leptons, nucleons, atoms and molecules, which consitute the source of several stringent constraints on new CP-violating physics. We dwell specifically on the calculational aspects of applying the hadronic EDM constraints, reviewing in detail the application of QCD sum-rules to the calculation of nucleon EDMs and CP-odd pion-nucleon couplings. We also consider the current status of EDMs in the Standard Model, and on the ensuing constraints on the underlying sources of CP-violation in physics beyond the Standard Model, focussing on weak-scale supersymmetry.

Determination of the TLD-100 physical parameters

International Nuclear Information System (INIS)

Paucar J, J.; Picon C, C.

1998-01-01

This study was realized in the Physics service at the Radiotherapy Department of the National Institute of Neoplasic Diseases in Lima, Peru, it was determined the activation energy, the kinetic order and the frequency factor of the fifth peak of the TLD-100 thermoluminescent spectra using different algorithms. This was carried out in parallel with the implementation and design of a software and an interface associated with the Tl lecturer which allows a semiautomatic control for a thermoluminescent lecturer process. (Author)

Physical Training for Long-Duration Spaceflight.

Science.gov (United States)

Loehr, James A; Guilliams, Mark E; Petersen, Nora; Hirsch, Natalie; Kawashima, Shino; Ohshima, Hiroshi

2015-12-01

Physical training has been conducted on the International Space Station (ISS) for the past 10 yr as a countermeasure to physiological deconditioning during spaceflight. Each member space agency has developed its own approach to creating and implementing physical training protocols for their astronauts. We have divided physical training into three distinct phases (preflight, in-flight, and postflight) and provided a description of each phase with its constraints and limitations. We also discuss how each member agency (NASA, ESA, CSA, and JAXA) prescribed physical training for their crewmembers during the first 10 yr of ISS operations. It is important to understand the operational environment, the agency responsible for the physical training program, and the constraints and limitations associated with spaceflight to accurately design and implement exercise training or interpret the exercise data collected on ISS. As exploration missions move forward, resolving agency differences in physical training programs will become important to maximizing the effectiveness of exercise as a countermeasure and minimizing any mission impacts.

Constraint algebra in Smolin's G →0 limit of 4D Euclidean gravity

Science.gov (United States)

Varadarajan, Madhavan

2018-05-01

Smolin's generally covariant GNewton→0 limit of 4d Euclidean gravity is a useful toy model for the study of the constraint algebra in loop quantum gravity (LQG). In particular, the commutator between its Hamiltonian constraints has a metric dependent structure function. While a prior LQG-like construction of nontrivial anomaly free constraint commutators for the model exists, that work suffers from two defects. First, Smolin's remarks on the inability of the quantum dynamics to generate propagation effects apply. Second, the construction only yields the action of a single Hamiltonian constraint together with the action of its commutator through a continuum limit of corresponding discrete approximants; the continuum limit of a product of two or more constraints does not exist. Here, we incorporate changes in the quantum dynamics through structural modifications in the choice of discrete approximants to the quantum Hamiltonian constraint. The new structure is motivated by that responsible for propagation in an LQG-like quantization of paramatrized field theory and significantly alters the space of physical states. We study the off shell constraint algebra of the model in the context of these structural changes and show that the continuum limit action of multiple products of Hamiltonian constraints is (a) supported on an appropriate domain of states, (b) yields anomaly free commutators between pairs of Hamiltonian constraints, and (c) is diffeomorphism covariant. Many of our considerations seem robust enough to be applied to the setting of 4d Euclidean gravity.

Maximally reliable Markov chains under energy constraints.

Science.gov (United States)

Escola, Sean; Eisele, Michael; Miller, Kenneth; Paninski, Liam

2009-07-01

Signal-to-noise ratios in physical systems can be significantly degraded if the outputs of the systems are highly variable. Biological processes for which highly stereotyped signal generations are necessary features appear to have reduced their signal variabilities by employing multiple processing steps. To better understand why this multistep cascade structure might be desirable, we prove that the reliability of a signal generated by a multistate system with no memory (i.e., a Markov chain) is maximal if and only if the system topology is such that the process steps irreversibly through each state, with transition rates chosen such that an equal fraction of the total signal is generated in each state. Furthermore, our result indicates that by increasing the number of states, it is possible to arbitrarily increase the reliability of the system. In a physical system, however, an energy cost is associated with maintaining irreversible transitions, and this cost increases with the number of such transitions (i.e., the number of states). Thus, an infinite-length chain, which would be perfectly reliable, is infeasible. To model the effects of energy demands on the maximally reliable solution, we numerically optimize the topology under two distinct energy functions that penalize either irreversible transitions or incommunicability between states, respectively. In both cases, the solutions are essentially irreversible linear chains, but with upper bounds on the number of states set by the amount of available energy. We therefore conclude that a physical system for which signal reliability is important should employ a linear architecture, with the number of states (and thus the reliability) determined by the intrinsic energy constraints of the system.

Three-dimensional image reconstruction. I. Determination of pattern orientation

International Nuclear Information System (INIS)

Blankenbecler, Richard

2004-01-01

The problem of determining the Euler angles of a randomly oriented three-dimensional (3D) object from its 2D Fraunhofer diffraction patterns is discussed. This problem arises in the reconstruction of a positive semidefinite 3D object using oversampling techniques. In such a problem, the data consist of a measured set of magnitudes from 2D tomographic images of the object at several unknown orientations. After the orientation angles are determined, the object itself can then be reconstructed by a variety of methods using oversampling, the magnitude data from the 2D images, physical constraints on the image, and then iteration to determine the phases

A Model of Contextual Motivation in Physical Education: Using Constructs from Self-Determination and Achievement Goal Theories To Predict Physical Activity Intentions.

Science.gov (United States)

Standage, Martyn; Duda, Joan L.; Ntoumanis, Nikos

2003-01-01

Examines a study of student motivation in physical education that incorporated constructs from achievement goal and self-determination theories. Self-determined motivation was found to positively predict, whereas amotivation was a negative predictor of leisure-time physical activity intentions. (Contains 86 references and 3 tables.) (GCP)

Testing a self-determination theory model of children's physical activity motivation: a cross-sectional study.

Science.gov (United States)

Sebire, Simon J; Jago, Russell; Fox, Kenneth R; Edwards, Mark J; Thompson, Janice L

2013-09-26

Understanding children's physical activity motivation, its antecedents and associations with behavior is important and can be advanced by using self-determination theory. However, research among youth is largely restricted to adolescents and studies of motivation within certain contexts (e.g., physical education). There are no measures of self-determination theory constructs (physical activity motivation or psychological need satisfaction) for use among children and no previous studies have tested a self-determination theory-based model of children's physical activity motivation. The purpose of this study was to test the reliability and validity of scores derived from scales adapted to measure self-determination theory constructs among children and test a motivational model predicting accelerometer-derived physical activity. Cross-sectional data from 462 children aged 7 to 11 years from 20 primary schools in Bristol, UK were analysed. Confirmatory factor analysis was used to examine the construct validity of adapted behavioral regulation and psychological need satisfaction scales. Structural equation modelling was used to test cross-sectional associations between psychological need satisfaction, motivation types and physical activity assessed by accelerometer. The construct validity and reliability of the motivation and psychological need satisfaction measures were supported. Structural equation modelling provided evidence for a motivational model in which psychological need satisfaction was positively associated with intrinsic and identified motivation types and intrinsic motivation was positively associated with children's minutes in moderate-to-vigorous physical activity. The study provides evidence for the psychometric properties of measures of motivation aligned with self-determination theory among children. Children's motivation that is based on enjoyment and inherent satisfaction of physical activity is associated with their objectively-assessed physical

Dose constraint for Industrial gammagraphy developed by regulatory authorities

International Nuclear Information System (INIS)

Salinas Mariaca, Rodrigo

2008-01-01

Aware that the dose limitation established by the Basic Safety Standards, is one of the radiation protection requirements necessary but not sufficient; and also aware that given the characteristics of the different practices and the culture of security already achieved in such practices, the workers occupationally exposed are far below from the respective limits. It becomes imperative to improve and exploit another of the requirements established by the referred standards, which is the Dose Constraint. This job takes as a basis the dose history having in the Bolivian Authority in nuclear issues, referred to the practices related to Nuclear Gauges, Well Logging, Radiotherapy and Industrial Gammagraphy (practices considered dangerous). This analysis is intended to be the pivot for the remainder practices and had as its goal, the establishment of a specific dose constraint value. The dose constraint suggested for every practices studied, were determined considering the percentile 95 and with the logic that if that 95% are able to achieve certain values of effective dose, the other 5% should be able to adapt their working conditions in order to decrease their doses. The spread of this work is intended not only aware, to other regulatory bodies to achieve a symbiosis between the different requirements of the Standard, but basically emphasize the fact that it is not convenient let the requirement of dose constraint exclusively in the hands of the regulated institutions and associated workers; making it, very subjective among those institutions according to their analysis (many times with no statistical support). Furthermore these dose constraint values should be determined previously to a new practice authorization or failing shortly after its implementation. (author)

Determinants of physical activity frequency and provider advice during pregnancy.

Science.gov (United States)

Santo, Eilann C; Forbes, Peter W; Oken, Emily; Belfort, Mandy B

2017-09-05

Our aims were to (1) describe the frequency of physical activity and prenatal healthcare provider advice about physical activity during pregnancy and (2) examine determinants and correlates of 3rd trimester physical activity and receipt of physical activity advice. We analyzed data from the 2008 Pregnancy Risk Assessment Monitoring System. We studied 2669 women from North Carolina and Colorado with data on physical activity frequency in the 3 months prior to pregnancy and during the 3rd trimester and 1584 women from Oklahoma with data on provider advice regarding physical activity during pregnancy. Respondents reported physical activity, defined as 30 min or more of exercise/physical activity (excluding vocationally related activity), in in these categories: pregnancy was strongly associated with low likelihood of ACOG guideline adherence in the 3rd trimester (aOR 0.10, 95% CU 0.04, 0.30 vs. 1-4 days/week). Underweight women were more likely to adhere to ACOG guidelines than normal weight women (aOR 2.27, 95% CI 1.36, 3.79). Overweight women were more likely to receive physical activity advice (aOR 2.9, 95% CI 1.3, 6.3 vs. normal weight), but obese women were not (aOR 0.65, 95% CI 0.4, 1.2). Few women meet ACOG guideline criteria for physical activity during pregnancy. Improving physical activity and weight status prior to pregnancy may improve activity levels during pregnancy. Nearly one third did not receive advice about physical activity during prenatal care. Obese women were no more likely to receive advice than their normal weight counterparts, indicating the need for targeted physical activity counseling in this population.

determination of some physical properties of three groundnut varieties

African Journals Online (AJOL)

Dr Obe

groundnuts. Three varieties of groundnuts namely ICGV-SM-93523, RMP-9 and RMP- 12 were collected and some of the physical properties, such as weight, angle of repose, coefficient of friction, bulk density, size, shape and moisture content were determined. The angle of repose for the three varieties was found to range ...

Current and future constraints on neutrino physics from cosmology

International Nuclear Information System (INIS)

Hannestad, S.; Hamann, J.; Wong, Y.Y.Y.

2014-01-01

In recent years precision cosmology has become an increasingly powerful probe of particle physics. Perhaps the prime example of this is the very stringent cosmological upper bound on the neutrino mass. However, other aspects of neutrino physics, such as their decoupling history and possible non-standard interactions, can be probed using observations of cosmic structure. Here, I review the current status of cosmological bounds on neutrino properties and discuss the potential of future observations, for example by the recently approved EUCLID mission, to precisely measure neutrino properties. (authors)

A statistical physics of stationary and metastable states

International Nuclear Information System (INIS)

Cabo, A; González, A; Curilef, S; Cabo-Bizet, N G; Vera, C A

2011-01-01

We present a generalization of Gibbs statistical mechanics designed to describe a general class of stationary and metastable equilibrium states. It is assumed that the physical system maximizes the entropy functional S subject to the standard conditions plus an extra conserved constraint function F, imposed to force the system to remain in the metastable configuration. After requiring additivity for two quasi-independent subsystems, and the commutation of the new constraint with the density matrix ρ, it is argued that F should be a homogeneous function of ρ, at least for systems in which the spectrum is sufficiently dense to be considered as continuous. Therefore, surprisingly, the analytic form of F turns out to be of the kind F(p i ) = p i q , where the p i are the eigenvalues of the density matrix and q is a real number to be determined. Thus, the discussion identifies the physical relevance of Lagrange multiplier constraints of the Tsallis kind and their q parameter, as enforced by the additivity of the constraint F which fixes the metastable state. An approximate analytic solution for the probability density is found for q close to unity. The procedure is applied to describe the results from the plasma experiment of Huang and Driscoll. For small and medium values of the radial distance, the measured density is predicted with a precision similar to that achieved by minimal enstrophy and Tsallis procedures. Also, the particle density is predicted at all the radial positions. Thus, the discussion gives a solution to the conceptual difficulties of the two above mentioned approaches as applied to this problem, which both predict a non-analytic abrupt vanishing of the density above a critical radial distance

Global Energy Development and Climate-Induced Water Scarcity—Physical Limits, Sectoral Constraints, and Policy Imperatives

Directory of Open Access Journals (Sweden)

Christopher A. Scott

2015-08-01

Full Text Available The current accelerated growth in demand for energy globally is confronted by water-resource limitations and hydrologic variability linked to climate change. The global spatial and temporal trends in water requirements for energy development and policy alternatives to address these constraints are poorly understood. This article analyzes national-level energy demand trends from U.S. Energy Information Administration data in relation to newly available assessments of water consumption and life-cycle impacts of thermoelectric generation and biofuel production, and freshwater availability and sectoral allocations from the U.N. Food and Agriculture Organization and the World Bank. Emerging, energy-related water scarcity flashpoints include the world’s largest, most diversified economies (Brazil, India, China, and USA among others, while physical water scarcity continues to pose limits to energy development in the Middle East and small-island states. Findings include the following: (a technological obstacles to alleviate water scarcity driven by energy demand are surmountable; (b resource conservation is inevitable, driven by financial limitations and efficiency gains; and (c institutional arrangements play a pivotal role in the virtuous water-energy-climate cycle. We conclude by making reference to coupled energy-water policy alternatives including water-conserving energy portfolios, intersectoral water transfers, virtual water for energy, hydropower tradeoffs, and use of impaired waters for energy development.

Determination of fault operation dynamical constraints for the design of wind turbine DFIG drives

CERN Document Server

Aguglia, Davide; Wamkeue, René; Cros, Jérôme

2010-01-01

This paper presents an efficient design tool for the estimation of the transient electromagnetic peak torque and transient rotor over-voltages of wind turbines (WT) doubly-fed induction generators (DFIG) during severe fault conditions on the grid side. This versatile and robust tool is well adapted to the implementation in a DFIG drives CAD environment using iterative optimization procedures. In such an application, it is used to compute the dynamical constraints function during the integrated design process of the whole drive including the generator, the gearbox and the power converters. Results show that it is necessary to take into account the dynamical constraints under fault operation, during the early steps of the system design process. Another application of the tool is also illustrated in the paper: the design of the protection system (i.e. the crowbar resistance) for a given generator, a given gearbox and a given power converter.

Crack-tip constraint analyses and constraint-dependent LBB curves for circumferential through-wall cracked pipes

Energy Technology Data Exchange (ETDEWEB)

Chen, Y.L.; Wang, G.Z., E-mail: gzwang@ecust.edu.cn; Xuan, F.Z.; Tu, S.T.

2015-04-15

Highlights: • Solution of constraint parameter τ* for through-wall cracked pipes has been obtained. • Constraint increases with increasing crack length and radius–thickness ratio of pipes. • Constraint-dependent LBB curve for through-wall cracked pipes has been constructed. • For increasing accuracy of LBB assessments, constraint effect should be considered. - Abstract: The leak-before-break (LBB) concept has been widely applied in the structural integrity assessments of pressured pipes in nuclear power plants. However, the crack-tip constraint effects in LBB analyses and designs cannot be incorporated. In this paper, by using three-dimensional finite element calculations, the modified load-independent T-stress constraint parameter τ* for circumferential through-wall cracked pipes with different geometries and crack sizes has been analyzed under different loading conditions, and the solutions of the crack-tip constraint parameter τ* have been obtained. Based on the τ* solutions and constraint-dependent J–R curves of a steel, the constraint-dependent LBB (leak-before-break) curves have been constructed. The results show that the constraint τ* increases with increasing crack length θ, mean radius R{sub m} and radius–thickness ratio R{sub m}/t of the pipes. In LBB analyses, the critical crack length calculated by the J–R curve of the standard high constraint specimen for pipes with shorter cracks is over-conservative, and the degree of conservatism increases with decreasing crack length θ, R{sub m} and R{sub m}/t. Therefore, the constraint-dependent LBB curves should be constructed to modify the over-conservatism and increase accuracy of LBB assessments.

Financial Constraints and Franchising Decisions

OpenAIRE

Kai-Uwe Kuhn; Francine Lafontaine; Ying Fan

2013-01-01

We study how the financial constraints of agents affect the behavior of principals in the context of franchising. We develop an empirical model of franchising starting with a principal-agent framework that emphasizes the role of franchisees' collateral from an incentive perspective. We estimate the determinants of chains' entry (into franchising) and growth decisions using data on franchised chains and data on local macroeconomic conditions. In particular, we use collateralizable housing weal...

Determinants of physical activity in primary school students using the health belief model

Directory of Open Access Journals (Sweden)

Ar-yuwat S

2013-03-01

Full Text Available Sireewat Ar-yuwat,1,2 Mary Jo Clark,2 Anita Hunter,3 Kathy S James2 1Boromarajonani College of Nursing Nakhon Lampang (BCNLP, Lampang, Thailand; 2Hahn School of Nursing and Health Science, University of San Diego, San Diego, CA, 3Department of Nursing, Dominican University of California, San Rafael, CA, USA Background: Thailand is a middle-income country in which two-thirds of children demonstrate an insufficient level of physical activity. Physical inactivity is a major risk factor for obesity and many other health-related consequences in children. Thus, it is important to understand how primary school children perceive things in their daily life as determinants of physical activity. The purpose of this study was to investigate the impact of cues, perceived benefits, and perceived barriers on the level of physical activity among primary school students. Methods: A cross-sectional study was conducted in Phitsanulok Province, Thailand, in 2011. Multistage sampling selected a total of 123 primary school students. The Physical Activity Questionnaire for Older Children and the Cues, Perceived Benefits, and Barriers to Physical Activity Questionnaire were used to assess the student levels of physical activity, as well as the perceived benefits, barriers, and cues to action. The association between these factors and the level of physical activity was determined by correlation statistics and confirmed by robust regression. Multivariate analysis of variance compared health belief model determinants: perceived benefits, perceived barriers, and cues to action on physical activity between male and female students. Self-administered questionnaires were validated and tested in a pilot study. Results: The level of activity among primary school children was significantly influenced by perceived barriers, such as fear of strangers when playing outdoors, bad weather, and too much homework. However, activity was not influenced by cues to action or perceived

Misconceptions and constraints

International Nuclear Information System (INIS)

Whitten, M.; Mahon, R.

2005-01-01

In theory, the sterile insect technique (SIT) is applicable to a wide variety of invertebrate pests. However, in practice, the approach has been successfully applied to only a few major pests. Chapters in this volume address possible reasons for this discrepancy, e.g. Klassen, Lance and McInnis, and Robinson and Hendrichs. The shortfall between theory and practice is partly due to the persistence of some common misconceptions, but it is mainly due to one constraint, or a combination of constraints, that are biological, financial, social or political in nature. This chapter's goal is to dispel some major misconceptions, and view the constraints as challenges to overcome, seeing them as opportunities to exploit. Some of the common misconceptions include: (1) released insects retain residual radiation, (2) females must be monogamous, (3) released males must be fully sterile, (4) eradication is the only goal, (5) the SIT is too sophisticated for developing countries, and (6) the SIT is not a component of an area-wide integrated pest management (AW-IPM) strategy. The more obvious constraints are the perceived high costs of the SIT, and the low competitiveness of released sterile males. The perceived high up-front costs of the SIT, their visibility, and the lack of private investment (compared with alternative suppression measures) emerge as serious constraints. Failure to appreciate the true nature of genetic approaches, such as the SIT, may pose a significant constraint to the wider adoption of the SIT and other genetically-based tactics, e.g. transgenic genetically modified organisms (GMOs). Lack of support for the necessary underpinning strategic research also appears to be an important constraint. Hence the case for extensive strategic research in ecology, population dynamics, genetics, and insect behaviour and nutrition is a compelling one. Raising the competitiveness of released sterile males remains the major research objective of the SIT. (author)

Physical activity, lifestyle and leisure constraints in a selected female ...

African Journals Online (AJOL)

Research has revealed that physical activity and a healthy lifestyle are inter alia considered as crucial factors in maintaining optimal health. These relationships are however influenced by age and sex. Women are often constrained in their ability to reach optimum levels of physical activity participation and healthy lifestyle.

Social Determinants of Physical Self-Rated Health among Asian Americans; Comparison of Six Ethnic Groups

Directory of Open Access Journals (Sweden)

Shervin Assari

2018-04-01

Full Text Available Background: A growing literature has revealed ethnic group differences in determinants and meanings of their self-rated health (SRH. Aim: To explore ethnic variations in the effects of socioeconomic determinants on poor physical SRH of Asians in the United States. Methods: Data came from the National Asian American Survey (NAAS, 2008, with 4977 non-U.S. born Asian Americans, including Asian Indian (n = 1150, Chinese (n = 1350, Filipino (n = 603, Japanese (n = 541, Korean (n = 614, and Vietnamese (n = 719 Americans. Demographic factors (age and gender, socioeconomic status (SES; education, employment, income, and marital status, and physical SRH were measured. Ethnic-specific logistic regressions were applied for data analysis where physical SRH was the outcome and demographic and social determinants were predictors. Results: According to logistic regressions, no social determinant was consistently associated with physical SRH across all ethnic groups. Being married was associated with better physical SRH in Asian Indians and worse SRH in the Filipino group. Education was associated with better SRH in Asian Indian, Chinese, Korean, and Vietnamese Americans. High income was associated with better SRH in Chinese, Filipino, and Vietnamese Americans. Employment was associated with better SRH in Filipino Americans. Conclusion: Social determinants of physical SRH vary across ethnic groups of Asian Americans. Different ethnic groups are differently vulnerable to various social determinants of health. Application of single item SRH measures may be a source of bias in studies of health with ethnically diverse populations. Policy makers should be aware that the same change in social determinants may not result in similar change in the health of ethnic groups.

Pramana – Journal of Physics | Indian Academy of Sciences

Indian Academy of Sciences (India)

Proceedings of the DAE–BRNS Ninth Workshop on High Energy Physics Phenomenology (WHEPP-9) - Part I. pp 559-560 ... 2006: Particle Physics in the Standard Model and beyond .... Physics. Cosmology with cosmic microwave background anisotropy ... Physics. Leptogenesis models and neutrino mass constraints.

Stronger constraints on non-Newtonian gravity from the Casimir effect

Energy Technology Data Exchange (ETDEWEB)

Mostepanenko, V M; Klimchitskaya, G L [Center of Theoretical Studies and Institute for Theoretical Physics, Leipzig University, D-04009, Leipzig (Germany); Decca, R S [Department of Physics, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202 (United States); Fischbach, E; Krause, D E [Department of Physics, Purdue University, West Lafayette, IN 47907 (United States); Lopez, D [Bell Laboratories, Lucent Technologies, Murray Hill, NJ 07974 (United States)

2008-04-25

We review new constraints on the Yukawa-type corrections to Newtonian gravity obtained recently from gravitational experiments and from the measurements of the Casimir force. Special attention is paid to the constraints following from the most precise dynamic determination of the Casimir pressure between the two parallel plates by means of a micromechanical torsional oscillator. The possibility of setting limits on the predictions of chameleon field theories using the results of gravitational experiments and Casimir force measurements is discussed.

How Do Severe Constraints Affect the Search Ability of Multiobjective Evolutionary Algorithms in Water Resources?

Science.gov (United States)

Clarkin, T. J.; Kasprzyk, J. R.; Raseman, W. J.; Herman, J. D.

2015-12-01

This study contributes a diagnostic assessment of multiobjective evolutionary algorithm (MOEA) search on a set of water resources problem formulations with different configurations of constraints. Unlike constraints in classical optimization modeling, constraints within MOEA simulation-optimization represent limits on acceptable performance that delineate whether solutions within the search problem are feasible. Constraints are relevant because of the emergent pressures on water resources systems: increasing public awareness of their sustainability, coupled with regulatory pressures on water management agencies. In this study, we test several state-of-the-art MOEAs that utilize restricted tournament selection for constraint handling on varying configurations of water resources planning problems. For example, a problem that has no constraints on performance levels will be compared with a problem with several severe constraints, and a problem with constraints that have less severe values on the constraint thresholds. One such problem, Lower Rio Grande Valley (LRGV) portfolio planning, has been solved with a suite of constraints that ensure high reliability, low cost variability, and acceptable performance in a single year severe drought. But to date, it is unclear whether or not the constraints are negatively affecting MOEAs' ability to solve the problem effectively. Two categories of results are explored. The first category uses control maps of algorithm performance to determine if the algorithm's performance is sensitive to user-defined parameters. The second category uses run-time performance metrics to determine the time required for the algorithm to reach sufficient levels of convergence and diversity on the solution sets. Our work exploring the effect of constraints will better enable practitioners to define MOEA problem formulations for real-world systems, especially when stakeholders are concerned with achieving fixed levels of performance according to one or

PHYSICAL-CONSTRAINT-PRESERVING CENTRAL DISCONTINUOUS GALERKIN METHODS FOR SPECIAL RELATIVISTIC HYDRODYNAMICS WITH A GENERAL EQUATION OF STATE

Energy Technology Data Exchange (ETDEWEB)

Wu, Kailiang [School of Mathematical Sciences, Peking University, Beijing 100871 (China); Tang, Huazhong, E-mail: wukl@pku.edu.cn, E-mail: hztang@math.pku.edu.cn [HEDPS, CAPT and LMAM, School of Mathematical Sciences, Peking University, Beijing 100871 (China)

2017-01-01

The ideal gas equation of state (EOS) with a constant adiabatic index is a poor approximation for most relativistic astrophysical flows, although it is commonly used in relativistic hydrodynamics (RHD). This paper develops high-order accurate, physical-constraints-preserving (PCP), central, discontinuous Galerkin (DG) methods for the one- and two-dimensional special RHD equations with a general EOS. It is built on our theoretical analysis of the admissible states for RHD and the PCP limiting procedure that enforce the admissibility of central DG solutions. The convexity, scaling invariance, orthogonal invariance, and Lax–Friedrichs splitting property of the admissible state set are first proved with the aid of its equivalent form. Then, the high-order central DG methods with the PCP limiting procedure and strong stability-preserving time discretization are proved, to preserve the positivity of the density, pressure, specific internal energy, and the bound of the fluid velocity, maintain high-order accuracy, and be L {sup 1}-stable. The accuracy, robustness, and effectiveness of the proposed methods are demonstrated by several 1D and 2D numerical examples involving large Lorentz factor, strong discontinuities, or low density/pressure, etc.

Dynamical Constraints on Non-Transiting Planets at Trappist-1

Science.gov (United States)

Jontof-Hutter, Daniel; Truong, Vinh; Ford, Eric; Robertson, Paul; Terrien, Ryan

2018-04-01

The outermost of the seven known planets of Trappist-1 orbits six times closer to its host star than Mercury orbits the sun. The architecture of this system beyond 0.07 AU remains unknown. While the presence of additional planets will ultimately be determined by observations, in the meantime, some constraints can be derived from dynamical models.We will firstly look at the expected signature of additional planets at Trappist-1 on the transit times of the known planets to determine at what distances putatuve planets can be ruled out.Secondly, the remarkably compact configuration of Trappist-1 ensures that the known planets are secularly coupled, keeping their mutual inclinations very small and making their cotransiting geometry likely if Trappist-1h transits. We determine the range of masses and orbital inclinations of a putatuve outer planet that would make the observed configuration unlikely, and compare these to these constraints to those expected from radial velocity observations.

Gamma ray constraints on flavor violating asymmetric dark matter

DEFF Research Database (Denmark)

Masina, I.; Panci, P.; Sannino, F.

2012-01-01

We show how cosmic gamma rays can be used to constrain models of asymmetric Dark Matter decaying into lepton pairs by violating flavor. First of all we require the models to explain the anomalies in the charged cosmic rays measured by PAMELA, Fermi and H.E.S.S.; performing combined fits we...... determine the allowed values of the Dark Matter mass and lifetime. For these models, we then determine the constraints coming from the measurement of the isotropic gamma-ray background by Fermi for a complete set of lepton flavor violating primary modes and over a range of DM masses from 100 GeV to 10 Te......V. We find that the Fermi constraints rule out the flavor violating asymmetric Dark Matter interpretation of the charged cosmic ray anomalies....

Implications of water constraints for electricity capacity expansion in the United States

Science.gov (United States)

Liu, L.; Hejazi, M. I.; Iyer, G.; Forman, B. A.

2017-12-01

U.S. electricity generation is vulnerable to water supply since water is required for cooling. Constraints on the availability of water will therefore necessitate adaptive planning by the power generation sector. Hence, it is important to integrate restrictions in water availability in electricity capacity planning in order to better understand the economic viability of alternative capacity planning options. The study of the implications of water constraints for the U.S. power generation system is limited in terms of scale and robustness. We extend previous studies by including physical water constraints in a state-level model of the U.S. energy system embedded within a global integrated assessment model (GCAM-USA). We focus on the implications of such constraints for the U.S. electricity capacity expansion, integrating both supply and demand effects under a consistent framework. Constraints on the availability of water have two general effects across the U.S. First, water availability constraints increase the cost of electricity generation, resulting in reduced electrification of end-use sectors. Second, water availability constraints result in forced retirements of water-intensive technologies such as thermoelectric coal- and gas- fired technologies before the end of their natural lifetimes. The demand for electricity is then met by an increase in investments in less water-dependent technologies such as wind and solar photovoltaic. Our results show that the regional patterns of the above effects are heterogeneous across the U.S. In general, the impacts of water constraints on electricity capacity expansion are more pronounced in the West than in the East. This is largely because of lower water availability in the West compared to the East due to lower precipitation in the Western states. Constraints on the availability of water might also have important implications for U.S. electricity trade. For example, under severe constraints on the availability of water

Constraints and Creativity in NPD - Testing the Impact of 'Late Constraints'

DEFF Research Database (Denmark)

Onarheim, Balder; Valgeirsdóttir, Dagný

experiment was conducted, involving 12 teams of industrial designers from three different countries, each team working on two 30 minutes design tasks. In one condition all constraints were given at the start, and in the other one new radical constraint was added after 12 minutes. The output from all 24 tasks......The aim of the presented work is to investigate how the timing of project constraints can influence the creativity of the output in New Product Development (NPD) projects. When seeking to produce a creative output, is it beneficial to know all constraints when initiating a project...... was assessed for creativity using the Consensual Assessment Technique (CAT), and a comparative within-subjects analysis found no significant different between the two conditions. Controlling for task and assessor a small but non-significant effect was found, in favor of the ‘late constraint’ condition. Thus...

Objectively determined habitual physical activity in South African adolescents: the PAHL study

Science.gov (United States)

2014-01-01

Background There is limited data on objectively determined habitual physical activity (PA) in 16-year old South African adolescents. The purpose of this study was to objectively determine the habitual PA of adolescents from the North West Province of South Africa by race and gender. Methods Adolescents (137 girls, 89 boys) from the ongoing Physical Activity and Health Longitudinal Study (PAHL study), participated in the present study. Habitual PA was objectively recorded by means of the Actiheart® over a period of 7 days. Time spent in moderate-to-vigorous intensity physical activity (MVPA) was assessed. Results Average MVPA for the study sample was 50.9 ± 40.3 minutes/day. Girls were significantly more active than boys expending more time in MVPA (61.13 ± 52.2 minutes/day; p Physical activity varies by both gender and race in adolescents from the North West Province of South Africa. Objectively determined data from our study indicates that girls habitually spend more time in MVPA per day than boys, and that white adolescents habitually engage in more MVPA than black adolescents. Seeing as the average MVPA per day for the entire study sample falls below the recommended daily average of 60minutes/day, adolescents should be the foremost targets of interventions aimed at enhancing habitual PA. PMID:24885503

Cosmology and particle physics

Energy Technology Data Exchange (ETDEWEB)

Steigman, G [California Univ., Santa Barbara (USA). Inst. for Theoretical Physics; Bartol Research Foundation, Newark, Delaware (USA))

1982-01-29

The cosmic connections between physics on the very largest and very smallest scales are reviewed with an emphasis on the symbiotic relation between elementary particle physics and cosmology. After a review of the early Universe as a cosmic accelerator, various cosmological and astrophysical constraints on models of particle physics are outlined. To illustrate this approach to particle physics via cosmology, reference is made to several areas of current research: baryon non-conservation and baryon asymmetry; free quarks, heavy hadrons and other exotic relics; primordial nucleosynthesis and neutrino masses.

Quantization of (2 + 1)-spinning particles and bifermionic constraint problem

Energy Technology Data Exchange (ETDEWEB)

Fresneda, R [Instituto de FIsica, Universidade de Sao Paulo, Caixa Postal 66318-CEP, 05315-970 Sao Paulo, SP (Brazil); Gavrilov, S P [Instituto de FIsica, Universidade de Sao Paulo, Caixa Postal 66318-CEP, 05315-970 Sao Paulo, SP (Brazil); Gitman, D M [Instituto de FIsica, Universidade de Sao Paulo, Caixa Postal 66318-CEP, 05315-970 Sao Paulo, SP (Brazil); Moshin, P Yu [Instituto de FIsica, Universidade de Sao Paulo, Caixa Postal 66318-CEP, 05315-970 Sao Paulo, SP (Brazil)

2004-03-21

This work is a natural continuation of our recent study in quantizing relativistic particles. There it was demonstrated that, by applying a consistent quantization scheme to the classical model of a spinless relativistic particle as well as to the Berezin-Marinov model of a 3 + 1 Dirac particle, it is possible to obtain a consistent relativistic quantum mechanics of such particles. In the present paper, we apply a similar approach to the problem of quantizing the massive 2 + 1 Dirac particle. However, we stress that such a problem differs in a nontrivial way from the one in 3 + 1 dimensions. The point is that in 2 + 1 dimensions each spin polarization describes different fermion species. Technically this fact manifests itself through the presence of a bifermionic constant and of a bifermionic first-class constraint. In particular, this constraint does not admit a conjugate gauge condition at the classical level. The quantization problem in 2 + 1 dimensions is also interesting from the physical viewpoint (e.g., anyons). In order to quantize the model, we first derive a classical formulation in an effective phase space, restricted by constraints and gauges. Then the condition of preservation of the classical symmetries allows us to realize the operator algebra in an unambiguous way and construct an appropriate Hilbert space. The physical sector of the constructed quantum mechanics contains spin-1/2 particles and antiparticles without an infinite number of negative-energy levels, and exactly reproduces the one-particle sector of the 2 + 1 quantum theory of a spinor field.

Physical Activity And Dietary Fat As Determinants Of Body Mass ...

African Journals Online (AJOL)

Overweight/obesity and related disease conditions will constitute a major threat to the economically productive adults and subsequently, will present a huge health-care burden on developing countries in the near future. Suspected determinants include physical activity and dietary fat. The main indicator of ...

Particle physics and cosmology, Task C

International Nuclear Information System (INIS)

Turner, M.S.

1993-05-01

The research has spanned many topics at the boundary of particle physics and cosmology. The major focus has been in the general areas of inflationary cosmology, cosmological phase transitions, astrophysical constraints to particle physics theories, and dark matter/structure formation as it relates to particle physics. Some attention is given to axion physics. Narrative summaries of the research of the individual group members are given, followed by a list of publications

Control of articulated snake robot under dynamic active constraints.

Science.gov (United States)

Kwok, Ka-Wai; Vitiello, Valentina; Yang, Guang-Zhong

2010-01-01

Flexible, ergonomically enhanced surgical robots have important applications to transluminal endoscopic surgery, for which path-following and dynamic shape conformance are essential. In this paper, kinematic control of a snake robot for motion stabilisation under dynamic active constraints is addressed. The main objective is to enable the robot to track the visual target accurately and steadily on deforming tissue whilst conforming to pre-defined anatomical constraints. The motion tracking can also be augmented with manual control. By taking into account the physical limits in terms of maximum frequency response of the system (manifested as a delay between the input of the manipulator and the movement of the end-effector), we show the importance of visual-motor synchronisation for performing accurate smooth pursuit movements. Detailed user experiments are performed to demonstrate the practical value of the proposed control mechanism.

Fourteen-Month-Olds Adapt Their Imitative Behavior in Light of a Model’s Constraints

Directory of Open Access Journals (Sweden)

Kata Gellén

2017-01-01

Full Text Available Rather than reenacting every action they observe, preverbal infants adapt their imitative behavior. Although previous studies have revealed the capability of preverbal infants to imitate selectively, the question about the adaptability of this behavior on an individual level did not attract considerable scientific attention until now. In the current study, we investigated whether 14-month-old infants flexibly alternate their imitative response in accordance with a model’s changing physical constraints in a body-part imitation paradigm. Participants were presented with two novel actions whereby a model illuminated a light-box and turned on a sound-box, either by using her forehead (head touch or by sitting on the apparatus (sit-touch. Each participant observed these tasks in two conditions: once where the model’s hands were occupied and once where her hands were free while executing the head or sit-touch. Participants were more likely to reenact the observed novel behavior when the model had freely chosen to perform it than when she had to do so due to physical constraints. Not only did we replicate a number of previous findings, we show here that preverbal infants adapt their imitative behavior across conditions based on the physical constraints of the model. These results point towards the adaptable nature of imitative behavior also on an individual level. This ability might be one of the building blocks for children for learning their social group’s specific action repertoire.

Testing a self-determination theory model of children’s physical activity motivation: a cross-sectional study

Science.gov (United States)

2013-01-01

Background Understanding children’s physical activity motivation, its antecedents and associations with behavior is important and can be advanced by using self-determination theory. However, research among youth is largely restricted to adolescents and studies of motivation within certain contexts (e.g., physical education). There are no measures of self-determination theory constructs (physical activity motivation or psychological need satisfaction) for use among children and no previous studies have tested a self-determination theory-based model of children’s physical activity motivation. The purpose of this study was to test the reliability and validity of scores derived from scales adapted to measure self-determination theory constructs among children and test a motivational model predicting accelerometer-derived physical activity. Methods Cross-sectional data from 462 children aged 7 to 11 years from 20 primary schools in Bristol, UK were analysed. Confirmatory factor analysis was used to examine the construct validity of adapted behavioral regulation and psychological need satisfaction scales. Structural equation modelling was used to test cross-sectional associations between psychological need satisfaction, motivation types and physical activity assessed by accelerometer. Results The construct validity and reliability of the motivation and psychological need satisfaction measures were supported. Structural equation modelling provided evidence for a motivational model in which psychological need satisfaction was positively associated with intrinsic and identified motivation types and intrinsic motivation was positively associated with children’s minutes in moderate-to-vigorous physical activity. Conclusions The study provides evidence for the psychometric properties of measures of motivation aligned with self-determination theory among children. Children’s motivation that is based on enjoyment and inherent satisfaction of physical activity is

Canonical quantization of model Hamiltonian in gauge theory. Relation between constraints and subsidiary conditions

International Nuclear Information System (INIS)

Sugano, R.; Kimura, T.

1985-01-01

As a model of gauge theory, it is investigated a system of point particles described by a singular Lagrangian from the standpoint of our formulation of constrained dynamical systems which was developed in the series of previous papers. Canonical quantization is carried out by two methods in order to clarify the role of the secondary constraints and their conjugate gauge constraints. The first method is to find a full set of the stationary external constraints and use the Dirac bracket. The other is to fix the gauges and remove unphysical states by imposing subsidiary condition on the state vectors. It is shown that unphysical components associated with a series of primary and secondary constraints are removed by a single subsidiary condition for each gauge degree. There appear an unphysical state with negative norm and a physical state with zero norm. It implies that the appearance of states with indefinite metrics is not due to the metric structure of space-time but is ascribed to gauge properties

Multi-Objective Trajectory Optimization of a Hypersonic Reconnaissance Vehicle with Temperature Constraints

Science.gov (United States)

Masternak, Tadeusz J.

This research determines temperature-constrained optimal trajectories for a scramjet-based hypersonic reconnaissance vehicle by developing an optimal control formulation and solving it using a variable order Gauss-Radau quadrature collocation method with a Non-Linear Programming (NLP) solver. The vehicle is assumed to be an air-breathing reconnaissance aircraft that has specified takeoff/landing locations, airborne refueling constraints, specified no-fly zones, and specified targets for sensor data collections. A three degree of freedom scramjet aircraft model is adapted from previous work and includes flight dynamics, aerodynamics, and thermal constraints. Vehicle control is accomplished by controlling angle of attack, roll angle, and propellant mass flow rate. This model is incorporated into an optimal control formulation that includes constraints on both the vehicle and mission parameters, such as avoidance of no-fly zones and coverage of high-value targets. To solve the optimal control formulation, a MATLAB-based package called General Pseudospectral Optimal Control Software (GPOPS-II) is used, which transcribes continuous time optimal control problems into an NLP problem. In addition, since a mission profile can have varying vehicle dynamics and en-route imposed constraints, the optimal control problem formulation can be broken up into several "phases" with differing dynamics and/or varying initial/final constraints. Optimal trajectories are developed using several different performance costs in the optimal control formulation: minimum time, minimum time with control penalties, and maximum range. The resulting analysis demonstrates that optimal trajectories that meet specified mission parameters and constraints can be quickly determined and used for larger-scale operational and campaign planning and execution.

Determinants of leisure-time physical activity and future intention to practice in Spanish college students.

Science.gov (United States)

Molina-García, Javier; Castillo, Isabel; Pablos, Carlos

2009-05-01

Few studies analyze determinants and patterns of physical activity among college students, so it has not been possible to carry out effective interventions to promote this practice. The aim of this study was to analyze the associations between some personal, social, and environmental determinants, practice of physical activity and future intention to practice in a sample of 639 university students (321 men and 318 women), mean age 21.43 years (+/- 2.78). Physical fitness self-perception, physical activity history, and coach's support to practice physical activity have a direct effect on the practice of physical activity and an indirect effect on future intention to practice, both in men and women. The practice of physical activity has also a direct effect on future intention to practice. Likewise, the participation in sport competitions predicts practice of physical activity and future intention in men, whereas being a member of a sports club predicts practice and future intention in women.

Optimization of an implicit constrained multi-physics system for motor wheels of electric vehicle

International Nuclear Information System (INIS)

Lei, Fei; Du, Bin; Liu, Xin; Xie, Xiaoping; Chai, Tian

2016-01-01

In this paper, implicit constrained multi-physics model of a motor wheel for an electric vehicle is built and then optimized. A novel optimization approach is proposed to solve the compliance problem between implicit constraints and stochastic global optimization. Firstly, multi-physics model of motor wheel is built from the theories of structural mechanics, electromagnetism and thermal physics. Then, implicit constraints are applied from the vehicle performances and magnetic characteristics. Implicit constrained optimization is carried out by a series of unconstrained optimization and verifications. In practice, sequentially updated subspaces are designed to completely substitute the original design space in local areas. In each subspace, a solution is obtained and is then verified by the implicit constraints. Optimal solutions which satisfy the implicit constraints are accepted as final candidates. The final global optimal solution is optimized from those candidates. Discussions are carried out to discover the differences between optimal solutions with unconstrained problem and different implicit constrained problems. Results show that the implicit constraints have significant influences on the optimal solution and the proposed approach is effective in finding the optimals. - Highlights: • An implicit constrained multi-physics model is built for sizing a motor wheel. • Vehicle dynamic performances are applied as implicit constraints for nonlinear system. • An efficient novel optimization is proposed to explore the constrained design space. • The motor wheel is optimized to achieve maximum efficiency on vehicle dynamics. • Influences of implicit constraints on vehicle performances are compared and analyzed.

Searching for genomic constraints

Energy Technology Data Exchange (ETDEWEB)

Lio` , P [Cambridge, Univ. (United Kingdom). Genetics Dept.; Ruffo, S [Florence, Univ. (Italy). Fac. di Ingegneria. Dipt. di Energetica ` S. Stecco`

1998-01-01

The authors have analyzed general properties of very long DNA sequences belonging to simple and complex organisms, by using different correlation methods. They have distinguished those base compositional rules that concern the entire genome which they call `genomic constraints` from the rules that depend on the `external natural selection` acting on single genes, i. e. protein-centered constraints. They show that G + C content, purine / pyrimidine distributions and biological complexity of the organism are the most important factors which determine base compositional rules and genome complexity. Three main facts are here reported: bacteria with high G + C content have more restrictions on base composition than those with low G + C content; at constant G + C content more complex organisms, ranging from prokaryotes to higher eukaryotes (e.g. human) display an increase of repeats 10-20 nucleotides long, which are also partly responsible for long-range correlations; work selection of length 3 to 10 is stronger in human and in bacteria for two distinct reasons. With respect to previous studies, they have also compared the genomic sequence of the archeon Methanococcus jannaschii with those of bacteria and eukaryotes: it shows sometimes an intermediate statistical behaviour.

Searching for genomic constraints

International Nuclear Information System (INIS)

Lio', P.; Ruffo, S.

1998-01-01

The authors have analyzed general properties of very long DNA sequences belonging to simple and complex organisms, by using different correlation methods. They have distinguished those base compositional rules that concern the entire genome which they call 'genomic constraints' from the rules that depend on the 'external natural selection' acting on single genes, i. e. protein-centered constraints. They show that G + C content, purine / pyrimidine distributions and biological complexity of the organism are the most important factors which determine base compositional rules and genome complexity. Three main facts are here reported: bacteria with high G + C content have more restrictions on base composition than those with low G + C content; at constant G + C content more complex organisms, ranging from prokaryotes to higher eukaryotes (e.g. human) display an increase of repeats 10-20 nucleotides long, which are also partly responsible for long-range correlations; work selection of length 3 to 10 is stronger in human and in bacteria for two distinct reasons. With respect to previous studies, they have also compared the genomic sequence of the archeon Methanococcus jannaschii with those of bacteria and eukaryotes: it shows sometimes an intermediate statistical behaviour

Black hole constraints on the running-mass inflation model

OpenAIRE

Leach, Samuel M; Grivell, Ian J; Liddle, Andrew R

2000-01-01

The running-mass inflation model, which has strong motivation from particle physics, predicts density perturbations whose spectral index is strongly scale-dependent. For a large part of parameter space the spectrum rises sharply to short scales. In this paper we compute the production of primordial black holes, using both analytic and numerical calculation of the density perturbation spectra. Observational constraints from black hole production are shown to exclude a large region of otherwise...

Qualitative and quantitative physical land evaluation : an operational approach

NARCIS (Netherlands)

Lanen, van H.A.J.

1991-01-01

Physical land evaluation methods are crucial for evaluating potentials and constraints of land for intended land use. Physical resources, such as soil, climate, hydrology, and topography are evaluated. Different technical procedures are used for physical land evaluation ranging from simple

A constraint logic programming approach to associate 1D and 3D structural components for large protein complexes.

Science.gov (United States)

Dal Palù, Alessandro; Pontelli, Enrico; He, Jing; Lu, Yonggang

2007-01-01

The paper describes a novel framework, constructed using Constraint Logic Programming (CLP) and parallelism, to determine the association between parts of the primary sequence of a protein and alpha-helices extracted from 3D low-resolution descriptions of large protein complexes. The association is determined by extracting constraints from the 3D information, regarding length, relative position and connectivity of helices, and solving these constraints with the guidance of a secondary structure prediction algorithm. Parallelism is employed to enhance performance on large proteins. The framework provides a fast, inexpensive alternative to determine the exact tertiary structure of unknown proteins.

Determination of first year students’ physical condition and physical fitness level

Directory of Open Access Journals (Sweden)

V.G. Fotynyuk

2017-06-01

Full Text Available Purpose: to study and find out first year students’ physical condition and physical fitness levels. Material: In the research first year students (n=86 participated. The age of the participants was 16 - 19 years. They passed the following tests for physical fitness: 100 meters’ run; run during 12 minutes; long jump from the spot; chin ups; torso rising from lying to sitting position during 1 minute; forward torso bending from sitting position, cm. Results: it was found that 41% of students have low and below average levels of physical condition and 76.35% - the same physical fitness level (unsatisfactory. So we came to conclusion that it was necessary to review the existing approaches to physical education system. It is recommended to increase the volume of compulsory classes of students’ motor functioning at the cost of the following: usage of optional classes; physical exercises’ practicing in free time; everyday motor activity in the form of morning exercises and sport games. Conclusions: the main reasons of students’ physical condition and physical fitness weakening during their studying are: restricted quantity of academic physical education classes; absence of students’ demand in systemic physical exercises’ practicing; students’ low motivation for physical education; absence of interest in physical exercises’ practicing in free time; students’ health worsening before entering higher educational establishment; imperfectness of school physical education.

A Test of Self-Determination Theory in School Physical Education

Science.gov (United States)

Standage, Martyn; Duda, Joan L.; Ntoumanis, Nikos

2005-01-01

Background: Contemporary research conducted in the context of school physical education (PE) has increasingly embraced various tenets of self-determination theory (Deci & Ryan, 1985, 1991). Despite this increase in research attention, some postulates of the framework remain unexplored (e.g. impact of a need-supportive climate). As such, the…

Financing Constraints and Entrepreneurship

OpenAIRE

William R. Kerr; Ramana Nanda

2009-01-01

Financing constraints are one of the biggest concerns impacting potential entrepreneurs around the world. Given the important role that entrepreneurship is believed to play in the process of economic growth, alleviating financing constraints for would-be entrepreneurs is also an important goal for policymakers worldwide. We review two major streams of research examining the relevance of financing constraints for entrepreneurship. We then introduce a framework that provides a unified perspecti...

Creativity from Constraints in Engineering Design

DEFF Research Database (Denmark)

Onarheim, Balder

2012-01-01

This paper investigates the role of constraints in limiting and enhancing creativity in engineering design. Based on a review of literature relating constraints to creativity, the paper presents a longitudinal participatory study from Coloplast A/S, a major international producer of disposable...... and ownership of formal constraints played a crucial role in defining their influence on creativity – along with the tacit constraints held by the designers. The designers were found to be highly constraint focused, and four main creative strategies for constraint manipulation were observed: blackboxing...

Observational constraints on the physical nature of submillimetre source multiplicity: chance projections are common

Science.gov (United States)

Hayward, Christopher C.; Chapman, Scott C.; Steidel, Charles C.; Golob, Anneya; Casey, Caitlin M.; Smith, Daniel J. B.; Zitrin, Adi; Blain, Andrew W.; Bremer, Malcolm N.; Chen, Chian-Chou; Coppin, Kristen E. K.; Farrah, Duncan; Ibar, Eduardo; Michałowski, Michał J.; Sawicki, Marcin; Scott, Douglas; van der Werf, Paul; Fazio, Giovanni G.; Geach, James E.; Gurwell, Mark; Petitpas, Glen; Wilner, David J.

2018-05-01

Interferometric observations have demonstrated that a significant fraction of single-dish submillimetre (submm) sources are blends of multiple submm galaxies (SMGs), but the nature of this multiplicity, i.e. whether the galaxies are physically associated or chance projections, has not been determined. We performed spectroscopy of 11 SMGs in six multicomponent submm sources, obtaining spectroscopic redshifts for nine of them. For an additional two component SMGs, we detected continuum emission but no obvious features. We supplement our observed sources with four single-dish submm sources from the literature. This sample allows us to statistically constrain the physical nature of single-dish submm source multiplicity for the first time. In three (3/7, { or} 43^{+39 }_{ -33} {per cent at 95 {per cent} confidence}) of the single-dish sources for which the nature of the blending is unambiguous, the components for which spectroscopic redshifts are available are physically associated, whereas 4/7 (57^{+33 }_{ -39} per cent) have at least one unassociated component. When components whose spectra exhibit continuum but no features and for which the photometric redshift is significantly different from the spectroscopic redshift of the other component are also considered, 6/9 (67^{+26 }_{ -37} per cent) of the single-dish sources are comprised of at least one unassociated component SMG. The nature of the multiplicity of one single-dish source is ambiguous. We conclude that physically associated systems and chance projections both contribute to the multicomponent single-dish submm source population. This result contradicts the conventional wisdom that bright submm sources are solely a result of merger-induced starbursts, as blending of unassociated galaxies is also important.

Physical (a)causality determinism, randomness and uncaused events

CERN Document Server

Svozil, Karl

2018-01-01

This book is open access under a CC BY 4.0 license. This book addresses the physical phenomenon of events that seem to occur spontaneously and without any known cause. These are to be contrasted with events that happen in a (pre-)determined, predictable, lawful, and causal way. All our knowledge is based on self-reflexive theorizing, as well as on operational means of empirical perception. Some of the questions that arise are the following: are these limitations reflected by our models? Under what circumstances does chance kick in? Is chance in physics merely epistemic? In other words, do we simply not know enough, or use too crude levels of description for our predictions? Or are certain events "truly", that is, irreducibly, random? The book tries to answer some of these questions by introducing intrinsic, embedded observers and provable unknowns; that is, observables and procedures which are certified (relative to the assumptions) to be unknowable or undoable. A (somewhat iconoclastic) review of quantum mec...

Transactive-Market-Based Operation of Distributed Electrical Energy Storage with Grid Constraints

Directory of Open Access Journals (Sweden)

M. Nazif Faqiry

2017-11-01

Full Text Available In a transactive energy market, distributed energy resources (DERs such as dispatchable distributed generators (DGs, electrical energy storages (EESs, distribution-scale load aggregators (LAs, and renewable energy sources (RESs have to earn their share of supply or demand through a bidding process. In such a market, the distribution system operator (DSO may optimally schedule these resources, first in a forward market, i.e., day-ahead, and in a real-time market later on, while maintaining a reliable and economic distribution grid. In this paper, an efficient day-ahead scheduling of these resources, in the presence of interaction with wholesale market at the locational marginal price (LMP, is studied. Due to inclusion of EES units with integer constraints, a detailed mixed integer linear programming (MILP formulation that incorporates simplified DistFlow equations to account for grid constraints is proposed. Convex quadratic line and transformer apparent power flow constraints have been linearized using an outer approximation. The proposed model schedules DERs based on distribution locational marginal price (DLMP, which is obtained as the Lagrange multiplier of the real power balance constraint at each distribution bus while maintaining physical grid constraints such as line limits, transformer limits, and bus voltage magnitudes. Case studies are performed on a modified IEEE 13-bus system with high DER penetration. Simulation results show the validity and efficiency of the proposed model.

Development and application of a unified balancing approach with multiple constraints

Science.gov (United States)

Zorzi, E. S.; Lee, C. C.; Giordano, J. C.

1985-01-01

The development of a general analytic approach to constrained balancing that is consistent with past influence coefficient methods is described. The approach uses Lagrange multipliers to impose orbit and/or weight constraints; these constraints are combined with the least squares minimization process to provide a set of coupled equations that result in a single solution form for determining correction weights. Proper selection of constraints results in the capability to: (1) balance higher speeds without disturbing previously balanced modes, thru the use of modal trial weight sets; (2) balance off-critical speeds; and (3) balance decoupled modes by use of a single balance plane. If no constraints are imposed, this solution form reduces to the general weighted least squares influence coefficient method. A test facility used to examine the use of the general constrained balancing procedure and application of modal trial weight ratios is also described.

General constraints on the age and chemical evolution of the Galaxy

International Nuclear Information System (INIS)

Meyer, B.S.; Schramm, D.N.

1986-05-01

The formalism of Schramm and Wasserburg (1970) for determining the mean age of the elements is extended. Model-independent constraints (constraints that are independent of a specific form for the effective nucleosynthesis rate and Galactic chemical evolution over time) are derived on the first four terms in the expansion giving the mean age of the elements, and from these constraints limits are derived on the total duration of nucleosynthesis. These limits require only input of the Schramm-Wasserburg parameter Δ/sup max/ and of the ratio of the mean time for formation of the elements to the total duration of nucleosynthesis, t/sub nu//T. The former quantity is a function of nuclear input parameters. Limits on the latter are obtained from constraints on the relative rate of nucleosynthesis derived from the 232 Th/ 238 U, 235 U/ 238 U, and shorter-lived chronometric pairs. 65 refs

Deepening Contractions and Collateral Constraints

DEFF Research Database (Denmark)

Jensen, Henrik; Ravn, Søren Hove; Santoro, Emiliano

and occasionally non-binding credit constraints. Easier credit access increases the likelihood that constraints become slack in the face of expansionary shocks, while contractionary shocks are further amplified due to tighter constraints. As a result, busts gradually become deeper than booms. Based...

Geographical Variations in the Environmental Determinants of Physical Inactivity among U.S. Adults.

Science.gov (United States)

An, Ruopeng; Li, Xinye; Jiang, Ning

2017-10-31

Physical inactivity is a major modifiable risk factor for morbidity, disability and premature mortality worldwide. This study assessed the geographical variations in the impact of environmental quality on physical inactivity among U.S. adults. Data on county-level prevalence of leisure-time physical inactivity came from the Behavioral Risk Factor Surveillance System. County environment was measured by the Environmental Quality Index (EQI), a comprehensive index of environmental conditions that affect human health. The overall EQI consists of five subdomains-air, water, land, social, and built environment. Geographically weighted regressions (GWRs) were performed to estimate and map county-specific impact of overall EQI and its five subdomains on physical inactivity prevalence. The prevalence of leisure-time physical inactivity among U.S. counties was 25% in 2005. On average, one standard deviation decrease in the overall EQI was associated with an increase in county-level prevalence of leisure-time physical inactivity by nearly 1%. However, substantial geographical variations in the estimated environmental determinants of physical inactivity were present. The estimated changes of county-level prevalence of leisure-time physical inactivity resulted from one standard deviation decrease of the overall EQI ranged from an increase of over 3% to a decrease of nearly 2% across U.S. counties. Analogous, the estimated changes of county-level prevalence of leisure-time physical inactivity resulted from one standard deviation decrease of the EQI air, water, land, social, and built environment subdomains ranged from an increase of 2.6%, 1.5%, 2.9%, 3.3%, and 1.7% to a decrease of 2.9%, 1.4%, 2.4%, 2.4%, and 0.8% across U.S. counties, respectively. Given the substantial heterogeneities in the environmental determinants of physical inactivity, locally customized physical activity interventions are warranted to address the most concerning area-specific environmental issue.

Physics from symmetry

CERN Document Server

Schwichtenberg, Jakob

2015-01-01

This is a textbook that derives the fundamental theories of physics from symmetry.   It starts by introducing, in a completely self-contained way, all mathematical tools needed to use symmetry ideas in physics. Thereafter, these tools are put into action and by using symmetry constraints, the fundamental equations of Quantum Mechanics, Quantum Field Theory, Electromagnetism, and Classical Mechanics are derived. As a result, the reader is able to understand the basic assumptions behind, and the connections between the modern theories of physics. The book concludes with first applications of the previously derived equations.

Multi-dimensional Bin Packing Problems with Guillotine Constraints

DEFF Research Database (Denmark)

Amossen, Rasmus Resen; Pisinger, David

2010-01-01

The problem addressed in this paper is the decision problem of determining if a set of multi-dimensional rectangular boxes can be orthogonally packed into a rectangular bin while satisfying the requirement that the packing should be guillotine cuttable. That is, there should exist a series of face...... parallel straight cuts that can recursively cut the bin into pieces so that each piece contains a box and no box has been intersected by a cut. The unrestricted problem is known to be NP-hard. In this paper we present a generalization of a constructive algorithm for the multi-dimensional bin packing...... problem, with and without the guillotine constraint, based on constraint programming....

Experimental constraints on light scalar field models in cosmology and particle physics (SNLS and CMS experiments)

International Nuclear Information System (INIS)

Neveu, Jeremy

2014-01-01

The nature of dark energy and dark matter is still unknown today. Light scalar field models have been proposed to explain the late-time accelerated expansion of the Universe and the apparent abundance of non-baryonic matter. In the first part of this thesis, the Galileon theory, a well-posed modified gravity theory preserving the local gravitation thanks to the Vainshtein screening effect, is accurately tested against recent cosmological data. Observational constraints are derived on the model parameters using cosmological distance and growth rate of structure measurements. A good agreement is observed between data and theory predictions. The Galileon theory appears therefore as a promising alternative to the cosmological constant scenario. In the second part, the dark matter question is explored through an extra-dimension theory containing massive and stable scalar fields called Branons. Branon production is searched for in the proton-proton collisions that were collected by the Compact Muon Solenoid experiment in 2012 at the Large Hadron Collider. Events with a single photon and transverse missing energy are selected in this data set and compared to the Standard Model and instrumental background estimates. No signature of new physics is observed, so experimental limits on the Branon model parameters are derived. This thesis concludes with some ideas to reach an unified description of both models in the frame of extra-dimension theories. (author) [fr

Deconstructing the neutrino mass constraint from galaxy redshift surveys

Science.gov (United States)

Boyle, Aoife; Komatsu, Eiichiro

2018-03-01

The total mass of neutrinos can be constrained in a number of ways using galaxy redshift surveys. Massive neutrinos modify the expansion rate of the Universe, which can be measured using baryon acoustic oscillations (BAOs) or the Alcock-Paczynski (AP) test. Massive neutrinos also change the structure growth rate and the amplitude of the matter power spectrum, which can be measured using redshift-space distortions (RSD). We use the Fisher matrix formalism to disentangle these information sources, to provide projected neutrino mass constraints from each of these probes alone and to determine how sensitive each is to the assumed cosmological model. We isolate the distinctive effect of neutrino free-streaming on the matter power spectrum and structure growth rate as a signal unique to massive neutrinos that can provide the most robust constraints, which are relatively insensitive to extensions to the cosmological model beyond ΛCDM . We also provide forecasted constraints using all of the information contained in the observed galaxy power spectrum combined, and show that these maximally optimistic constraints are primarily limited by the accuracy to which the optical depth of the cosmic microwave background, τ, is known.

Stakeholders' influence on the importance of users' and clients' information and constraints during website design.

Science.gov (United States)

Chevalier, Aline

2007-12-01

The present study aims at determining the role of the stakeholder (via a user vs a client spokesperson) on the importance allocated to information and constraints considered by novice and professional web designers. Analysis showed all designers focused mainly on clients' constraints and information even when they dealt with a user spokesperson: they considered clients' constraints as more important than users' constraints. These results are new with regard to those previously obtained in web design, which showed designers considered prescribed constraints (regardless of the stakeholder to which they are related) as unavaoidable, and the vast majority of others as avoidable if required. Research is required to help web designers to ponder users' and clients' constraints and to assess whether the same patterns of results occur in other design domains.

Occupational dose constraint

International Nuclear Information System (INIS)

Heilbron Filho, Paulo Fernando Lavalle; Xavier, Ana Maria

2005-01-01

The revision process of the international radiological protection regulations has resulted in the adoption of new concepts, such as practice, intervention, avoidable and restriction of dose (dose constraint). The latter deserving of special mention since it may involve reducing a priori of the dose limits established both for the public and to individuals occupationally exposed, values that can be further reduced, depending on the application of the principle of optimization. This article aims to present, with clarity, from the criteria adopted to define dose constraint values to the public, a methodology to establish the dose constraint values for occupationally exposed individuals, as well as an example of the application of this methodology to the practice of industrial radiography

Particle physics and cosmology

International Nuclear Information System (INIS)

Turner, M.S.; Schramm, D.N.

1985-01-01

During the past year, the research of the members of our group has spanned virtually all the topics at the interface of cosmology and particle physics: inflationary Universe scenarios, astrophysical and cosmological constraints on particle properties, ultra-high energy cosmic ray physics, quantum field theory in curved space-time, cosmology with extra dimensions, superstring cosmology, neutrino astronomy with large, underground detectors, and the formation of structure in the Universe

Major constraints affecting aquaculture development in Akwa Ibom ...

African Journals Online (AJOL)

The study contributes to nationwide attempts to enhance the contributions of aquaculture to the fishery subsector, and consequent overall gross domestic product of Nigeria, as well as to the protein intake of her citizenry. The focus is on the determination of the magnitude of constraints affecting aquaculture development in ...

Returns, productivity and constraints analyses of cassava/maize ...

African Journals Online (AJOL)

The study was conducted in Isi-Uzo LGA of Enugu State, and evaluated the productivity and profitability of cassava/maize/melon mixed cropping with the aim to determine the degree and direction of influence of the production factors and identification of constraints militating against the enterprise. Multistage and purposive ...

Nuclear spin content and constraints on exotic spin-dependent couplings

International Nuclear Information System (INIS)

Kimball, D F Jackson

2015-01-01

There are numerous recent and ongoing experiments employing a variety of atomic species to search for couplings of atomic spins to exotic fields. In order to meaningfully compare these experimental results, the coupling of the exotic field to the atomic spin must be interpreted in terms of the coupling to electron, proton, and neutron spins. Traditionally, constraints from atomic experiments on exotic couplings to neutron and proton spins have been derived using the single-particle Schmidt model for nuclear spin. In this model, particular atomic species are sensitive to either neutron or proton spin couplings, but not both. More recently, semi-empirical models employing nuclear magnetic moment data have been used to derive new constraints for non-valence nucleons. However, comparison of such semi-empirical models to detailed large-scale nuclear shell model calculations and analysis of known physical effects in nuclei show that existing semi-empirical models cannot reliably be used to predict the spin polarization of non-valence nucleons. The results of our re-analysis of nuclear spin content are applied to searches for exotic long-range monopole–dipole and dipole–dipole couplings of nuclei leading to significant revisions of some published constraints. (paper)

Automatic determination of pressurized water reactor core loading patterns which maximize end-of-cycle reactivity within power peaking and burnup constraints

International Nuclear Information System (INIS)

Hobson, G.H.

1985-01-01

An automated procedure for determining the optimal core loading pattern for a pressurized water reactor which maximizes end-of-cycle k/sub eff/ while satisfying constraints on power peaking and discharge burnup has been developed. The optimization algorithm combines a two energy group, two-dimensional coarse-mesh finite difference diffusion theory neutronics model to simulate core conditions, a perturbation theory approach to determine reactivity, flux, power and burnup changes as a function of assembly shuffling, and Monte Carlo integer programming to select the optimal loading pattern solution. The core examined was a typical Cycle 2 reload with no burnable poisons. Results indicate that the core loading pattern that maximizes end-of-cycle k/sub eff/ results in a 5.4% decrease in fuel cycle costs compared with the core loading pattern that minimizes the maximum relative radial power peak

Determinants of physical activity among people with spinal cord injury: a test of social cognitive theory.

Science.gov (United States)

Ginis, Kathleen A Martin; Latimer, Amy E; Arbour-Nicitopoulos, Kelly P; Bassett, Rebecca L; Wolfe, Dalton L; Hanna, Steven E

2011-08-01

Little theory-based research has focused on understanding and increasing physical activity among people with physical disabilities. Testing a social cognitive theory-based model of determinants is important for identifying variables to target in physical activity-enhancing interventions. The aim of this study is to examine Social Cognitive Theory variables as predictors of physical activity among people living with spinal cord injury. Structural equation modeling was used to test a model of Social Cognitive Theory predictors of physical activity (n=160). The model explained 39% of the variance in physical activity. Self-regulation was the only significant, direct predictor. Self-regulatory efficacy and outcome expectations had indirect effects, mediated by self-regulation. Social Cognitive Theory is useful for predicting physical activity in people with spinal cord injury. Self-regulation is the most potent Social Cognitive Theory predictor of physical activity in people with spinal cord injury. Self-regulation and its determinants should be targeted in physical activity-enhancing interventions.

The Physical Constraints on a New LoBAL QSO at z = 4.82

Energy Technology Data Exchange (ETDEWEB)

Yi, Weimin; Bai, Jin-Ming [Yunnan Observatories, Chinese Academy of Sciences, Kunming 650216 (China); Green, Richard; Fan, Xiaohui; Milne, Peter [Steward Observatory, University of Arizona, Tucson, AZ 85721-0065 (United States); Wang, Tinggui; Yang, Chenwei [CAS Key Laboratory for Research in Galaxies and Cosmology, Department of Astronomy, University of Science and Technology of China (China); Grier, Catherine J.; Trump, Jonathan R.; Brandt, William N. [Department of Astronomy and Astrophysics and Institute for Gravitation and the Cosmos, The Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States); Zuo, Wenwen [Shanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030 (China); Yang, Jinyi; Wang, Feige; Wu, Xue-Bing; Jiang, Linhua; Yang, Qian [Department of Astronomy, School of Physics, Peking University, Beijing 100871 (China); Zhou, Hongyan [Polar Research Institute of China, 451 Jinqiao Road, Shanghai 200136 (China); Varricatt, Watson; Kerr, Tom; Benigni, Sam [UKIRT Observatory, Hilo, HI 96720 (United States); and others

2017-04-01

Very few low-ionization broad absorption line (LoBAL) QSOs have been found at high redshifts, to date. One high-redshift LoBAL QSO, J0122+1216, was recently discovered by the Lijiang 2.4 m Telescope, with an initial redshift determination of 4.76. Aiming to investigate its physical properties, we carried out follow-up observations in the optical and near-IR spectroscopy. Near-IR spectra from UKIRT and P200 confirm that it is a LoBAL, with a new redshift determination of 4.82 ± 0.01 based on the Mg ii emission-line. The new Mg ii redshift determination reveals strong blueshifts and asymmetry of the high-ionization emission lines. We estimate a black hole mass of ∼2.3 × 10{sup 9} M {sub ⊙} and Eddington ratio of ∼1.0 according to the empirical Mg ii-based single-epoch relation and bolometric correction factor. It is possible that strong outflows are the result of an extreme quasar environment driven by the high Eddington ratio. A lower limit on the outflowing kinetic power (>0.9% L {sub Edd}) is derived from both emission and absorption lines, indicating that these outflows play a significant role in the feedback process that regulates the growth of its black hole, as well as host galaxy evolution.

Solar constraints

International Nuclear Information System (INIS)

Provost, J.

1984-01-01

Accurate tests of the theory of stellar structure and evolution are available from the Sun's observations. The solar constraints are reviewed, with a special attention to the recent progress in observing global solar oscillations. Each constraint is sensitive to a given region of the Sun. The present solar models (standard, low Z, mixed) are discussed with respect to neutrino flux, low and high degree five-minute oscillations and low degree internal gravity modes. It appears that actually there do not exist solar models able to fully account for all the observed quantities. (Auth.)

Vandenberg Air Force Base Upper Level Wind Launch Weather Constraints

Science.gov (United States)

Shafer, Jaclyn A.; Wheeler, Mark M.

2012-01-01

The 30th Operational Support Squadron Weather Flight (30 OSSWF) provides comprehensive weather services to the space program at Vandenberg Air Force Base (VAFB) in California. One of their responsibilities is to monitor upper-level winds to ensure safe launch operations of the Minuteman III ballistic missile. The 30 OSSWF tasked the Applied Meteorology Unit (AMU) to analyze VAFB sounding data with the goal of determining the probability of violating (PoV) their upper-level thresholds for wind speed and shear constraints specific to this launch vehicle, and to develop a tool that will calculate the PoV of each constraint on the day of launch. In order to calculate the probability of exceeding each constraint, the AMU collected and analyzed historical data from VAFB. The historical sounding data were retrieved from the National Oceanic and Atmospheric Administration Earth System Research Laboratory archive for the years 1994-2011 and then stratified into four sub-seasons: January-March, April-June, July-September, and October-December. The maximum wind speed and 1000-ft shear values for each sounding in each subseason were determined. To accurately calculate the PoV, the AMU determined the theoretical distributions that best fit the maximum wind speed and maximum shear datasets. Ultimately it was discovered that the maximum wind speeds follow a Gaussian distribution while the maximum shear values follow a lognormal distribution. These results were applied when calculating the averages and standard deviations needed for the historical and real-time PoV calculations. In addition to the requirements outlined in the original task plan, the AMU also included forecast sounding data from the Rapid Refresh model. This information provides further insight for the launch weather officers (LWOs) when determining if a wind constraint violation will occur over the next few hours on day of launch. The interactive graphical user interface (GUI) for this project was developed in

Growth curves and sustained commissioning modelling of renewable energy: Investigating resource constraints for wind energy

International Nuclear Information System (INIS)

Davidsson, Simon; Grandell, Leena; Wachtmeister, Henrik; Höök, Mikael

2014-01-01

Several recent studies have proposed fast transitions to energy systems based on renewable energy technology. Many of them dismiss potential physical constraints and issues with natural resource supply, and do not consider the growth rates of the individual technologies needed or how the energy systems are to be sustained over longer time frames. A case study is presented modelling potential growth rates of the wind energy required to reach installed capacities proposed in other studies, taking into account the expected service life of wind turbines. A sustained commissioning model is proposed as a theoretical foundation for analysing reasonable growth patterns for technologies that can be sustained in the future. The annual installation and related resource requirements to reach proposed wind capacity are quantified and it is concluded that these factors should be considered when assessing the feasibility, and even the sustainability, of fast energy transitions. Even a sustained commissioning scenario would require significant resource flows, for the transition as well as for sustaining the system, indefinitely. Recent studies that claim there are no potential natural resource barriers or other physical constraints to fast transitions to renewable energy appear inadequate in ruling out these concerns. - Highlights: • Growth rates and service life is important when evaluating energy transitions. • A sustained commissioning model is suggested for analysing renewable energy. • Natural resource requirements for renewable energy are connected to growth rates. • Arguments by recent studies ruling out physical constraints appear inadequate

Determining Purpose of Academic Discipline “Physical Education” for Future Teachers

Directory of Open Access Journals (Sweden)

Ж. О. Цимбалюк

2016-09-01

Full Text Available The research objective is to determine the purpose of physical education in pedagogical higher educational institutions. Materials and methods. The research used: theoretical analysis and collation of scientific literature; study of guidelines and documents regulating the process of organizing and conducting the discipline “Physical Education” in a higher educational institution; questionnaires. The participants of the experiment were 60 first-year students (enrolled in 2015-2016 of the School of Ukrainian Language and Literature of H. S. Skovoroda Kharkiv National Pedagogical University. Research results. The analysis of the questionnaires revealed low rates of motivational variants in the choice of the sports section related to the future profession. The research specified the purpose of the discipline “Physical Education” in a pedagogical higher educational institution, and defined the health-preserving competence. Conclusions. The specific nature of the pedagogical profession requires that future teachers acquire the health-preserving competence within the discipline “Physical Education”, namely, the ability to maintain a general level of physical health needed to conduct social and professional activity.

The Power of the Capability Constraint: On Russia’s Strength in the Arctic Territorial Dispute

Directory of Open Access Journals (Sweden)

Valko Irina

2016-04-01

Full Text Available Based on a geographical-administrative definition of the region, the theoretical assumptions of contemporary French structuralist geopolitics, cross-sectional data for 1990, 1995, 2000, 2005 and 2010 from the Updated Arctic Regional Attributes Dataset, and the technical capabilities of MS Office Excel 2010, this research (a reveals and contrasts the Arctic states’ capability constraints deriving from their longitudinal material and virtual power potential (physical potential, socio-economic potential, military potential, and symbolic potential; and (b analyses the role of this constraint in the process of preference formation in case of one specific Arctic actor, Russia, in the Arctic territorial dispute. This study confirms that Russia’s capability constraint is the lowest in the region and that the latter does not form a stable trend throughout the period studied. It also suggests the preference formation framework for Russia in the Arctic dispute based on the evolution of its polar capability constraint.

Temporal Concurrent Constraint Programming

DEFF Research Database (Denmark)

Nielsen, Mogens; Valencia Posso, Frank Dan

2002-01-01

The ntcc calculus is a model of non-deterministic temporal concurrent constraint programming. In this paper we study behavioral notions for this calculus. In the underlying computational model, concurrent constraint processes are executed in discrete time intervals. The behavioral notions studied...... reflect the reactive interactions between concurrent constraint processes and their environment, as well as internal interactions between individual processes. Relationships between the suggested notions are studied, and they are all proved to be decidable for a substantial fragment of the calculus...

Impact of flavor and Higgs physics on theories beyond the standard model

Energy Technology Data Exchange (ETDEWEB)

Casagrande, Sandro

2013-02-13

Quantum effects of physics beyond the Standard Model receive strong indirect constraints from precisely measured collider observables. In the conceptual part of this thesis, we apply the generic relations between particle interactions in perturbatively unitary theories to calculate one-loop amplitudes for flavor physics. We provide template results applicable for any model of this class. We also investigate example models that are partly and such that are not perturbatively unitary: the Littlest Higgs model and Randall-Sundrum models. The latter have a unique coupling structure, which we cover exhaustively. We find strong constraints on the Randall-Sundrum models and numerically compare those from flavor, electroweak precision, and Higgs physics by performing detailed parameter scans. We observe interesting correlations between flavor observables, and we find that constraints from Higgs production and decays are already competitive.

Impact of flavor and Higgs physics on theories beyond the standard model

International Nuclear Information System (INIS)

Casagrande, Sandro

2013-01-01

Quantum effects of physics beyond the Standard Model receive strong indirect constraints from precisely measured collider observables. In the conceptual part of this thesis, we apply the generic relations between particle interactions in perturbatively unitary theories to calculate one-loop amplitudes for flavor physics. We provide template results applicable for any model of this class. We also investigate example models that are partly and such that are not perturbatively unitary: the Littlest Higgs model and Randall-Sundrum models. The latter have a unique coupling structure, which we cover exhaustively. We find strong constraints on the Randall-Sundrum models and numerically compare those from flavor, electroweak precision, and Higgs physics by performing detailed parameter scans. We observe interesting correlations between flavor observables, and we find that constraints from Higgs production and decays are already competitive.

Estimating Crustal Properties Directly from Satellite Tracking Data by Using a Topography-based Constraint

Science.gov (United States)

Goossens, S. J.; Sabaka, T. J.; Genova, A.; Mazarico, E. M.; Nicholas, J. B.; Neumann, G. A.; Lemoine, F. G.

2017-12-01

The crust of a terrestrial planet is formed by differentiation processes in its early history, followed by magmatic evolution of the planetary surface. It is further modified through impact processes. Knowledge of the crustal structure can thus place constraints on the planet's formation and evolution. In particular, the average bulk density of the crust is a fundamental parameter in geophysical studies, such as the determination of crustal thickness, studies of the mechanisms of topography support, and the planet's thermo-chemical evolution. Yet even with in-situ samples available, the crustal density is difficult to determine unambiguously, as exemplified by the results for the Gravity and Recovery Interior Laboratory (GRAIL) mission, which found an average crustal density for the Moon that was lower than generally assumed. The GRAIL results were possible owing to the combination of its high-resolution gravity and high-resolution topography obtained by the Lunar Orbiter Laser Altimeter (LOLA) onboard the Lunar Reconnaissance Orbiter (LRO), and high correlations between the two datasets. The crustal density can be determined by its contribution to the gravity field of a planet, but at long wavelengths flexure effects can dominate. On the other hand, short-wavelength gravity anomalies are difficult to measure, and either not determined well enough (other than at the Moon), or their power is suppressed by the standard `Kaula' regularization constraint applied during inversion of the gravity field from satellite tracking data. We introduce a new constraint that has infinite variance in one direction, called xa . For constraint damping factors that go to infinity, it can be shown that the solution x becomes equal to a scale factor times xa. This scale factor is completely determined by the data, and we call our constraint rank-minus-1 (RM1). If we choose xa to be topography-induced gravity, then we can estimate the average bulk crustal density directly from the data

Motivation and Physical Activity Behaviors among Older Women: A Self-Determination Perspective

Science.gov (United States)

Stephan, Yannick; Boiche, Julie; Le Scanff, Christine

2010-01-01

Drawing upon Self-Determination Theory, the purpose of our study was to examine the motivational determinants of older women's dropout and participation in physical activity (PA). Older women who dropped out (n = 242) or remained (n = 332) in an organized PA program completed the Sport Motivation Scale as well as health and PA measures. We found…

Hydrostatic equilibrium of stars without electroneutrality constraint

Science.gov (United States)

Krivoruchenko, M. I.; Nadyozhin, D. K.; Yudin, A. V.

2018-04-01

The general solution of hydrostatic equilibrium equations for a two-component fluid of ions and electrons without a local electroneutrality constraint is found in the framework of Newtonian gravity theory. In agreement with the Poincaré theorem on analyticity and in the context of Dyson's argument, the general solution is demonstrated to possess a fixed (essential) singularity in the gravitational constant G at G =0 . The regular component of the general solution can be determined by perturbation theory in G starting from a locally neutral solution. The nonperturbative component obtained using the method of Wentzel, Kramers and Brillouin is exponentially small in the inner layers of the star and grows rapidly in the outward direction. Near the surface of the star, both components are comparable in magnitude, and their nonlinear interplay determines the properties of an electro- or ionosphere. The stellar charge varies within the limits of -0.1 to 150 C per solar mass. The properties of electro- and ionospheres are exponentially sensitive to variations of the fluid densities in the central regions of the star. The general solutions of two exactly solvable stellar models without a local electroneutrality constraint are also presented.

Theory of Constraints (TOC)

DEFF Research Database (Denmark)

Michelsen, Aage U.

2004-01-01

Tankegangen bag Theory of Constraints samt planlægningsprincippet Drum-Buffer-Rope. Endvidere skitse af The Thinking Process.......Tankegangen bag Theory of Constraints samt planlægningsprincippet Drum-Buffer-Rope. Endvidere skitse af The Thinking Process....

Prospects for new physics in τ→lμμ at current and future colliders

Energy Technology Data Exchange (ETDEWEB)

Hays, Chris [Department of Physics, Oxford University,Keble Road, Oxford, OX1 3RH (United Kingdom); Mitra, Manimala [Department of Physics,Indian Institute of Science Education and Research Mohali (IISER Mohali),Sector 81, SAS Nagar, Manauli 140306 (India); Institute for Particle Physics Phenomenology, Department of Physics, Durham University,South Road, Durham, DH1 3LE (United Kingdom); Spannowsky, Michael; Waite, Philip [Institute for Particle Physics Phenomenology, Department of Physics, Durham University,South Road, Durham, DH1 3LE (United Kingdom)

2017-05-03

The discovery of lepton flavour violating interactions will be striking evidence for physics beyond the Standard Model. Focusing on the three decays τ{sup ∓}→μ{sup ±}μ{sup ∓}μ{sup ∓}, τ{sup ∓}→e{sup ±}μ{sup ∓}μ{sup ∓} and τ{sup ∓}→e{sup ∓}μ{sup ∓}μ{sup ±}, we evaluate the discovery potential of current and future high-energy colliders to probe lepton flavour violation in the τ sector. Based on this potential we determine the expected constraints on parameters of new physics in the context of the Type-II Seesaw Model, the Left-Right Symmetric Model, and the Minimal Supersymmetric Standard Model. The existing and ongoing 13 TeV run of the Large Hadron Collider has the potential to produce constraints that outperform the existing e{sup +}e{sup −} collider limits for the τ{sup ∓}→μ{sup ±}μ{sup ∓}μ{sup ∓} decay and achieve a branching fraction limit of ≲10{sup −8}. With a future circular e{sup +}e{sup −} collider, constraints on the τ→lμμ branching fractions could reach as low as a few times 10{sup −12}.

Psychological determinants of physical activity across the life course: A "DEterminants of DIet and Physical ACtivity" (DEDIPAC umbrella systematic literature review.

Directory of Open Access Journals (Sweden)

Cristina Cortis

Full Text Available Low levels of physical activity (PA are reported to contribute to the occurrence of non-communicable diseases over the life course. Although psychological factors have been identified as an important category concerning PA behavior, knowledge on psychological determinants of PA is still inconclusive. Therefore, the aim of this umbrella systematic literature review (SLR was to summarize and synthesize the scientific evidence on psychological determinants of PA behavior across the life course. A systematic online search was conducted on MEDLINE, ISI Web of Science, Scopus, and SPORTDiscus databases. The search was limited to studies published in English from January 2004 to April 2016. SLRs and meta-analyses (MAs of observational studies investigating the association of psychological variables and PA were considered eligible. Extracted data were evaluated based on importance of determinants, strength of evidence, and methodological quality. The full protocol is available from PROSPERO (Record ID: CRD42015010616. Twenty reviews (14 SLRs and 6 MAs, mostly of moderate methodological quality, were found eligible. Convincing evidence was found for self-efficacy (positive association with PA in children and adolescents, and stress (negative association with PA regardless of age. Most of the evidence revealing an association between psychological determinants and PA is probable and limited, mainly due to differences in the definition of PA and of psychological determinants across reviews. Thus, scholars are urged to reach a consensus on clear definitions of relevant psychological determinants of PA, subsuming cultural biases and allowing the possibility to obtain clear interpretations and generalizability of findings. Finally, most psychological determinants should be considered within a larger framework of other multi-level determinants that may interact or mediate some of the effects.

Constraint Embedding for Multibody System Dynamics

Science.gov (United States)

Jain, Abhinandan

2009-01-01

This paper describes a constraint embedding approach for the handling of local closure constraints in multibody system dynamics. The approach uses spatial operator techniques to eliminate local-loop constraints from the system and effectively convert the system into tree-topology systems. This approach allows the direct derivation of recursive O(N) techniques for solving the system dynamics and avoiding the expensive steps that would otherwise be required for handling the closedchain dynamics. The approach is very effective for systems where the constraints are confined to small-subgraphs within the system topology. The paper provides background on the spatial operator O(N) algorithms, the extensions for handling embedded constraints, and concludes with some examples of such constraints.

Ensemble Kalman filtering in presence of inequality constraints

Science.gov (United States)

van Leeuwen, P. J.

2009-04-01

Kalman filtering is presence of constraints is an active area of research. Based on the Gaussian assumption for the probability-density functions, it looks hard to bring in extra constraints in the formalism. On the other hand, in geophysical systems we often encounter constraints related to e.g. the underlying physics or chemistry, which are violated by the Gaussian assumption. For instance, concentrations are always non-negative, model layers have non-negative thickness, and sea-ice concentration is between 0 and 1. Several methods to bring inequality constraints into the Kalman-filter formalism have been proposed. One of them is probability density function (pdf) truncation, in which the Gaussian mass from the non-allowed part of the variables is just equally distributed over the pdf where the variables are alolwed, as proposed by Shimada et al. 1998. However, a problem with this method is that the probability that e.g. the sea-ice concentration is zero, is zero! The new method proposed here does not have this drawback. It assumes that the probability-density function is a truncated Gaussian, but the truncated mass is not distributed equally over all allowed values of the variables, but put into a delta distribution at the truncation point. This delta distribution can easily be handled with in Bayes theorem, leading to posterior probability density functions that are also truncated Gaussians with delta distributions at the truncation location. In this way a much better representation of the system is obtained, while still keeping most of the benefits of the Kalman-filter formalism. In the full Kalman filter the formalism is prohibitively expensive in large-scale systems, but efficient implementation is possible in ensemble variants of the kalman filter. Applications to low-dimensional systems and large-scale systems will be discussed.

Methodological aspects of values for determining the physical load in sport.

Directory of Open Access Journals (Sweden)

Chernozub A.A.

2012-09-01

Full Text Available The main aspects of the control system of training in sport and identified two methodological concepts determine the amount of physical activity during the training sessions. It is established that the physical training and sports activities in the course of employment estimate the value of physical activity mainly due to the reaction rates of the functional systems of the body to an external stimulus. Such an assessment, especially in a narrow range of controllable parameters (for the reaction of the cardiovascular and respiratory systems, is more theoretical in nature and does not allow to clearly define the critical load levels for a particular organism. This problem highlights the need to use a single, integrated, suitable for precise mathematical analysis of the universal, possibly conditional, indicator or criteria for evaluating physical activity. Development of this criterion will optimize the training process at different stages of training opportunities tailored to individual athletes.

Physical activity and determinants of sedentary behavior in Brazilian adolescents from an underdeveloped region.

Science.gov (United States)

Guedes, Dartagnan P; Souza, Monica V; Ferreirinha, Jose E; Silva, Antonio Jose R M

2012-04-01

The purpose of the study was to analyze the physical activity and the determinants of sedentary behavior in 1,268 Brazilian adolescents (638 girls, 630 boys) between the ages of 15 and 18 years, randomly selected from a relatively underdeveloped region. Data were collected from a community-based survey in the city of João Pessoa, Paraiba, Brazil. Information related to physical activity was derived on the short version of the International Physical Activity Questionnaire. The prevalence of sedentary behavior was 28.2% for girls and 19.1% for boys, whilst 28.9% of the girls and 36.7% of the boys showed high physical activity. The sedentary behavior varied by sociodemographic and environmental determinants studied. Parents' education, socioeconomic status, school's characteristics, transport to school, paid work, smoking, alcohol use, and BMI scores were significantly related to sedentary behavior for boys and girls.

Selection of new constraints

International Nuclear Information System (INIS)

Sugier, A.

2003-01-01

The selected new constraints should be consistent with the scale of concern i.e. be expressed roughly as fractions or multiples of the average annual background. They should take into account risk considerations and include the values of the currents limits, constraints and other action levels. The recommendation is to select four leading values for the new constraints: 500 mSv ( single event or in a decade) as a maximum value, 0.01 mSv/year as a minimum value; and two intermediate values: 20 mSv/year and 0.3 mSv/year. This new set of dose constraints, representing basic minimum standards of protection for the individuals taking into account the specificity of the exposure situations are thus coherent with the current values which can be found in ICRP Publications. A few warning need however to be noticed: There is no more multi sources limit set by ICRP. The coherence between the proposed value of dose constraint (20 mSv/year) and the current occupational dose limit of 20 mSv/year is valid only if the workers are exposed to one single source. When there is more than one source, it will be necessary to apportion. The value of 1000 mSv lifetimes used for relocation can be expressed into annual dose, which gives approximately 10 mSv/year and is coherent with the proposed dose constraint. (N.C.)

Energy constraints in pulsed phase control of chaos

International Nuclear Information System (INIS)

Meucci, R.; Euzzor, S.; Zambrano, S.; Pugliese, E.; Francini, F.; Arecchi, F.T.

2017-01-01

Phase control of chaos is a powerful technique but little is known about its physical constraints, relevant for real systems. As a fact, it has not been explored whether this technique can also be applied when the controlling perturbation is not harmonic. Here we apply phase control on a driven double well Duffing oscillator using periodic rectangular pulsed perturbations instead of the classical sinusoidal perturbations. Experimental measurements and numerical simulations show that this kind of perturbation is also able to stabilize the chaotic orbits for an adequate selection of the phase. Furthermore, as the duty cycle of the perturbation (that is, the fraction of the time that the periodically pulsed control is active) is increased, two separate regimes occur. In the first one, the perturbations leading to stabilization of periodic solutions are of constant energy (taken as the product of the duty cycle and the amplitude) and in the second one, a saturation phenomenon occurs, implying that increasing energy values of the perturbations are wasted. Our results unveil the versatility of the pulsed phase control scheme and the importance of energy constraints.

Energy constraints in pulsed phase control of chaos

Energy Technology Data Exchange (ETDEWEB)

Meucci, R., E-mail: riccardo.meucci@ino.it [Istituto Nazionale di Ottica, Consiglio Nazionale delle Ricerche, Largo E. Fermi 6, 50125 Firenze (Italy); Euzzor, S. [Istituto Nazionale di Ottica, Consiglio Nazionale delle Ricerche, Largo E. Fermi 6, 50125 Firenze (Italy); Zambrano, S. [Università Vita-Salute San Raffaele, Via Olgettina 58, 20132 Milano (Italy); Pugliese, E. [Istituto Nazionale di Ottica, Consiglio Nazionale delle Ricerche, Largo E. Fermi 6, 50125 Firenze (Italy); Dipartimento di Scienze della Terra, Università di Firenze, Via G. La Pira 4, 50100 Firenze (Italy); Francini, F. [Istituto Nazionale di Ottica, Consiglio Nazionale delle Ricerche, Largo E. Fermi 6, 50125 Firenze (Italy); Arecchi, F.T. [Istituto Nazionale di Ottica, Consiglio Nazionale delle Ricerche, Largo E. Fermi 6, 50125 Firenze (Italy); Università di Firenze, Firenze (Italy)

2017-01-15

Phase control of chaos is a powerful technique but little is known about its physical constraints, relevant for real systems. As a fact, it has not been explored whether this technique can also be applied when the controlling perturbation is not harmonic. Here we apply phase control on a driven double well Duffing oscillator using periodic rectangular pulsed perturbations instead of the classical sinusoidal perturbations. Experimental measurements and numerical simulations show that this kind of perturbation is also able to stabilize the chaotic orbits for an adequate selection of the phase. Furthermore, as the duty cycle of the perturbation (that is, the fraction of the time that the periodically pulsed control is active) is increased, two separate regimes occur. In the first one, the perturbations leading to stabilization of periodic solutions are of constant energy (taken as the product of the duty cycle and the amplitude) and in the second one, a saturation phenomenon occurs, implying that increasing energy values of the perturbations are wasted. Our results unveil the versatility of the pulsed phase control scheme and the importance of energy constraints.

WMAP constraints on inflationary models with global defects

International Nuclear Information System (INIS)

Bevis, Neil; Hindmarsh, Mark; Kunz, Martin

2004-01-01

We use the cosmic microwave background angular power spectra to place upper limits on the degree to which global defects may have aided cosmic structure formation. We explore this under the inflationary paradigm, but with the addition of textures resulting from the breaking of a global O(4) symmetry during the early stages of the Universe. As a measure of their contribution, we use the fraction of the temperature power spectrum that is attributed to the defects at a multipole of 10. However, we find a parameter degeneracy enabling a fit to the first-year WMAP data to be made even with a significant defect fraction. This degeneracy involves the baryon fraction and the Hubble constant, plus the normalization and tilt of the primordial power spectrum. Hence, constraints on these cosmological parameters are weakened. Combining the WMAP data with a constraint on the physical baryon fraction from big bang nucleosynthesis calculations and high-redshift deuterium abundance limits the extent of the degeneracy and gives an upper bound on the defect fraction of 0.13 (95% confidence)

Power generation capacity planning under budget constraint in developing countries

International Nuclear Information System (INIS)

Afful-Dadzie, Anthony; Afful-Dadzie, Eric; Awudu, Iddrisu; Banuro, Joseph Kwaku

2017-01-01

Highlights: • A long term stochastic GEP model with budget constraint is developed. • Model suitable for analyzing GEP problems in developing countries. • Model determines optimal mix, size and timing of future generation capacity needs. • A real case study of the Ghana GEP problem was employed. • Insufficient budget leads to costly generation capacity expansion plans. - Abstract: This paper presents a novel multi-period stochastic optimization model for studying long-term power generation capacity planning in developing countries. A stylized model is developed to achieve three objectives: (1) to serve as a tool for determining optimal mix, size and timing of power generation types in the face of budget constraint, (2) to help decision makers appreciate the consequences of capacity expansion decisions on level of unserved electricity demand and its attendant impact on the national economy, and (3) to encourage the habit of periodic savings towards new generation capacity financing. The problem is modeled using a stochastic mixed-integer linear programming (MILP) technique under demand uncertainty. The effectiveness of the model, together with valuable insights derived from considering different levels of budget constraints are demonstrated using Ghana as a case study. The results indicate that at an annual savings equivalent to 0.75% of GDP, Ghana could finance the needed generation capacity to meet approximately 95% of its annual electricity demand between 2016 and 2035. Additionally, it is observed that as financial constraint becomes tighter, decisions on the mix of new generation capacities tend to be more costly compared to when sufficient funds are available.

Minimal Flavor Constraints for Technicolor

DEFF Research Database (Denmark)

Sakuma, Hidenori; Sannino, Francesco

2010-01-01

We analyze the constraints on the the vacuum polarization of the standard model gauge bosons from a minimal set of flavor observables valid for a general class of models of dynamical electroweak symmetry breaking. We will show that the constraints have a strong impact on the self-coupling and mas......We analyze the constraints on the the vacuum polarization of the standard model gauge bosons from a minimal set of flavor observables valid for a general class of models of dynamical electroweak symmetry breaking. We will show that the constraints have a strong impact on the self...

Temporal Concurrent Constraint Programming

DEFF Research Database (Denmark)

Nielsen, Mogens; Palamidessi, Catuscia; Valencia, Frank Dan

2002-01-01

The ntcc calculus is a model of non-deterministic temporal concurrent constraint programming. In this paper we study behavioral notions for this calculus. In the underlying computational model, concurrent constraint processes are executed in discrete time intervals. The behavioral notions studied...

Exact Constraint Design and its potential for Robust Embodiment

DEFF Research Database (Denmark)

Eifler, Tobias; Howard, Thomas J.

2017-01-01

Constraint Design. Examples are the calculation of a mechanisms’ mobility using the Grübler-Kutzbach criterion, the analysis of statically determinate assemblies by means of the screw theory or so called Schlussartenmatrizen, as well as the analysis of engaging surfaces in terms of location schemes...

Behavioural Constraints on Practices of Auditing in Nigeria (BCPAN)

Science.gov (United States)

Akpomi, Margaret E.; Amesi, Joy

2009-01-01

This research was conducted to determine the behavioural constraints on practices of auditing (BCPAN) in Nigeria and to proffer strategies for making incidence of auditing (internal and external auditors) more effective. Thirty-seven administrators drawn from some public limited liability companies, private companies and tertiary institutions were…

The willingness and constraints to routing HIV screening among ...

African Journals Online (AJOL)

Methods: This descriptive cross- sectional study on 312 pregnant women attending antenatal clinic at Nnamdi Azikiwe University Teaching Hospital Nnewi, was carried out, to evaluate the knowledge of HIV/AIDS, the practice of voluntary HIV testing and also determine the constraints and motivation to voluntary HIV testing.

Variational principles of fluid mechanics and electromagnetism: imposition and neglect of the Lin constraint

International Nuclear Information System (INIS)

Allen, R.R. Jr.

1987-01-01

The Lin constraint has been utilized by a number of authors who have sought to develop Eulerian variational principles in both fluid mechanics and electromagnetics (or plasmadynamics). This dissertation first reviews the work of earlier authors concerning the development of variational principles in both the Eulerian and Lagrangian nomenclatures. In the process, it is shown whether or not the Euler-Lagrange equations that result from the variational principles are equivalent to the generally accepted equations of motion. In particular, it is shown in the case of several Eulerian variational principles that imposition of the Lin constraint results in Euler-Lagrange equations equivalent to the generally accepted equations of motion, whereas neglect of the Lin constraint results in restrictive Euler-Lagrange equations. In an effort to improve the physical motivation behind introduction of the Lin constraint, a new variational constraint is developed based on teh concept of surface forces within a fluid. Additionally, it is shown that a quantity often referred to as the canonical momentum of a charged fluid is not always a constant of the motion of the fluid; and it is demonstrated that there does not exist an unconstrained Eulerian variational principle giving rise to the generally accepted equations of motion for both a perfect fluid and a cold, electromagnetic fluid

TUnfold, an algorithm for correcting migration effects in high energy physics

Energy Technology Data Exchange (ETDEWEB)

Schmitt, Stefan

2012-07-15

TUnfold is a tool for correcting migration and background effects in high energy physics for multi-dimensional distributions. It is based on a least square fit with Tikhonov regularisation and an optional area constraint. For determining the strength of the regularisation parameter, the L-curve method and scans of global correlation coefficients are implemented. The algorithm supports background subtraction and error propagation of statistical and systematic uncertainties, in particular those originating from limited knowledge of the response matrix. The program is interfaced to the ROOT analysis framework.

Automatic determination of pressurized water reactor core loading patterns that maximize beginning-of-cycle reactivity within power-peaking and burnup constraints

International Nuclear Information System (INIS)

Hobson, G.H.; Turinsky, P.J.

1986-01-01

Computational capability has been developed to automatically determine a good estimate of the core loading pattern, which minimizes fuel cycle costs for a pressurized water reactor (PWR). Equating fuel cycle cost minimization with core reactivity maximization, the objective is to determine the loading pattern that maximizes core reactivity while satisfying power peaking, discharge burnup, and other constraints. The method utilizes a two-dimensional, coarse-mesh, finite difference scheme to evaluate core reactivity and fluxes for an initial reference loading pattern. First-order perturbation theory is applied to determine the effects of assembly shuffling on reactivity, power distribution, end-of-cycle burnup. Monte Carlo integer programming is then used to determine a near-optimal loading pattern within a range of loading patterns near the reference pattern. The process then repeats with the new loading pattern as the reference loading pattern and terminates when no better loading pattern can be determined. The process was applied with both reactivity maximization and radial power-peaking minimization as objectives. Results on a typical large PWR indicate that the cost of obtaining an 8% improvement in radial power-peaking margin is ≅2% in fuel cycle costs, for the reload core loaded without burnable poisons that was studied

The balance-of-payments constraint:from balanced trade to sustainable debt

Directory of Open Access Journals (Sweden)

Nelson H. Barbosa-Filho

2001-12-01

Full Text Available This paper extends the balance-of-payments constraint on growth known as Thirlwall's law to incorporate unbalanced trade and debt accumulation. Assuming that small open economies face a liquidity constraint, the text shows the growth and real-exchange-rate policy rules consistent with a stable ratio of net exports to income. Given such rules, the text shows how the trade balance of a small open economy is residually determined by the ratio of foreign debt to income allowed by international conditions.

Predicting physical activity and outcome expectations in cancer survivors: an application of Self-Determination Theory.

Science.gov (United States)

Wilson, Philip M; Blanchard, Chris M; Nehl, Eric; Baker, Frank

2006-07-01

The purpose of this study was to examine the contributions of autonomous and controlled motives drawn from Self-Determination Theory (SDT; Intrinsic Motivation and Self-determination in Human Behavior. Plenum Press: New York, 1985; Handbook of Self-determination Research. University of Rochester Press: New York, 2002) towards predicting physical activity behaviours and outcome expectations in adult cancer survivors. Participants were cancer-survivors (N=220) and a non-cancer comparison cohort (N=220) who completed an adapted version of the Treatment Self-Regulation Questionnaire modified for physical activity behaviour (TSRQ-PA), an assessment of the number of minutes engaged in moderate-to-vigorous physical activity (MVPA) weekly, and the anticipated outcomes expected from regular physical activity (OE). Simultaneous multiple regression analyses indicated that autonomous motives was the dominant predictor of OEs across both cancer and non-cancer cohorts (R(2adj)=0.29-0.43), while MVPA was predicted by autonomous (beta's ranged from 0.21 to 0.34) and controlled (beta's ranged from -0.04 to -0.23) motives after controlling for demographic considerations. Cancer status (cancer versus no cancer) did not moderate the motivation-physical activity relationship. Collectively, these findings suggest that the distinction between autonomous and controlled motives is useful and compliments a growing body of evidence supporting SDT as a framework for understanding motivational processes in physical activity contexts with cancer survivors.

Economic growth constraints in Vietnam: A study using the growth diagnostic approach

Directory of Open Access Journals (Sweden)

Nguyen Duc Thanh

2016-04-01

Full Text Available Recent studies have clearly pointed out a decreasing trend of Vietnam’s economic growth in the short and the medium terms. This paper presents a study applying the growth diagnostic method for Vietnam to determine growth constrains. The binding growth constrains of Vietnam are found to include a poor business environment; an underdeveloped infrastructure, especially the transportation network market; failures related to information externalities, learning externalities and coordination failures. Notably, the energy infrastructure could be a vital constraint in a near future, but is not a binding constraint at present. The inefficiency of financial intermediaries and the government’s over-investment could become a binding constraint when the economy returns to its high growth path.

Efficient Searching with Linear Constraints

DEFF Research Database (Denmark)

Agarwal, Pankaj K.; Arge, Lars Allan; Erickson, Jeff

2000-01-01

We show how to preprocess a set S of points in d into an external memory data structure that efficiently supports linear-constraint queries. Each query is in the form of a linear constraint xd a0+∑d−1i=1 aixi; the data structure must report all the points of S that satisfy the constraint. This pr...

Constraint qualifications and optimality conditions for optimization problems with cardinality constraints

Czech Academy of Sciences Publication Activity Database

Červinka, Michal; Kanzow, Ch.; Schwartz, A.

2016-01-01

Roč. 160, č. 1 (2016), s. 353-377 ISSN 0025-5610 R&D Projects: GA ČR GAP402/12/1309; GA ČR GA15-00735S Institutional support: RVO:67985556 Keywords : Cardinality constraints * Constraint qualifications * Optimality conditions * KKT conditions * Strongly stationary points Subject RIV: BA - General Mathematics Impact factor: 2.446, year: 2016 http://library.utia.cas.cz/separaty/2016/MTR/cervinka-0461165.pdf

Determinants of Physical Activity in Patients with Chronic Obstructive Pulmonary Disease: A 5-Year Prospective Follow-Up Study

NARCIS (Netherlands)

Yu, Tsung; Frei, Anja; ter Riet, Gerben; Puhan, Milo A.

2016-01-01

Although many studies examined determinants of physical activity in patients with chronic obstructive pulmonary disease (COPD), most were cross-sectional and focused on single determinants only. The aim of this study was to determine how COPD patients' physical activity changes over time and to

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...

Constraint specialisation in Horn clause verification

DEFF Research Database (Denmark)

Kafle, Bishoksan; Gallagher, John Patrick

2017-01-01

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 transformed version of a given set of clauses and a goal. The constraints from the model are then used to compute...... a specialised version of each clause. The effect is to propagate the constraints from the goal top-down and propagate answer constraints bottom-up. The specialisation procedure can be repeated to yield further specialisation. The approach is independent of the abstract domain and the constraint theory...

Periodic capacity management under a lead-time performance constraint

NARCIS (Netherlands)

Büyükkaramikli, N.C.; Bertrand, J.W.M.; Ooijen, van H.P.G.

2013-01-01

In this paper, we study a production system that operates under a lead-time performance constraint which guarantees the completion of an order before a pre-determined lead-time with a certain probability. The demand arrival times and the service requirements for the orders are random. To reduce the

Mapping the Developmental Constraints on Working Memory Span Performance

Science.gov (United States)

Bayliss, Donna M.; Jarrold, Christopher; Baddeley, Alan D.; Gunn, Deborah M.; Leigh, Eleanor

2004-01-01

This study investigated the constraints underlying developmental improvements in complex working memory span performance among 120 children of between 6 and 10 years of age. Independent measures of processing efficiency, storage capacity, rehearsal speed, and basic speed of processing were assessed to determine their contribution to age-related…

Constraints and entropy in a model of network evolution

Science.gov (United States)

Tee, Philip; Wakeman, Ian; Parisis, George; Dawes, Jonathan; Kiss, István Z.

2017-11-01

Barabási-Albert's "Scale Free" model is the starting point for much of the accepted theory of the evolution of real world communication networks. Careful comparison of the theory with a wide range of real world networks, however, indicates that the model is in some cases, only a rough approximation to the dynamical evolution of real networks. In particular, the exponent γ of the power law distribution of degree is predicted by the model to be exactly 3, whereas in a number of real world networks it has values between 1.2 and 2.9. In addition, the degree distributions of real networks exhibit cut offs at high node degree, which indicates the existence of maximal node degrees for these networks. In this paper we propose a simple extension to the "Scale Free" model, which offers better agreement with the experimental data. This improvement is satisfying, but the model still does not explain why the attachment probabilities should favor high degree nodes, or indeed how constraints arrive in non-physical networks. Using recent advances in the analysis of the entropy of graphs at the node level we propose a first principles derivation for the "Scale Free" and "constraints" model from thermodynamic principles, and demonstrate that both preferential attachment and constraints could arise as a natural consequence of the second law of thermodynamics.

Transmission and capacity pricing and constraints

International Nuclear Information System (INIS)

Fusco, M.

1999-01-01

A series of overhead viewgraphs accompanied this presentation which discussed the following issues regarding the North American electric power industry: (1) capacity pricing transmission constraints, (2) nature of transmission constraints, (3) consequences of transmission constraints, and (4) prices as market evidence. Some solutions suggested for pricing constraints included the development of contingent contracts, back-up power in supply regions, and new line capacity construction. 8 tabs., 20 figs

The energy in all states: data, constraints, stakes; L'energie sous toutes ses formes: donnees, contraintes, enjeux

Energy Technology Data Exchange (ETDEWEB)

Balian, R [Academie des Sciences, 92 - Gif sur Yvette (France); Combarnous, M [Bordeaux-1 Univ., LEPT-ENSAM, 33 - Talence (France); Lucas, J; Fauvarque, J F [Conservatoire National des Arts et Metiers (CNAM), 75 - Paris (France); Madet, D [Electricite de France (EDF), 75 - Paris (France); Bal, J L [Agence de l' Environnement et de la Maitrise de l' Energie, ADEME, 75 - Paris (France); Jourde, P [CEA Cadarache, GENEC, 13 - Saint-Paul-lez-Durance (France); Tissot, B [Commission Nationale d' Evaluation, 75 - Paris (France); Leconte, Ph [CEA Saclay, Dir. du Developpement et de l' Innovation Nucleares DDIN, 91 - Gif Sur Yvette (France); Doubre, H [Paris-11 Univ., IN2P3/CNRS, 91 - Orsay (France); Alleau, Th [Association Francaise de l' Hydrogene, AFH2, 75 - Paris (France); Durup, G [Mining Research Institute (United States); Le Treut, H [Ecole Nationale Superieure, 75 - Paris (France); Tubiana, M [Institut Gustave Roussy, 94 - Villejuif (France); [Centre Antoine Beclere, Paris (France); Masse, R [Office de Protection contre les Rayonnements Ionisants, 78 - le Vesinet (France); Lebot, B [Agence Internationale de l' Energie, 75 - Paris (France); Babusiaux, D [Institut Francais du Petrole (IFP), 92 - Rueil-Malmaison (France); Saab, A E [Electricite de France (EDF), 75 - Paris (France)

2002-07-01

This documents brings together papers presented at the physics summer school of august 2001 on the energy. The following topics are discussed: the constraints bound to the physics and the scales, the renewable energies, the future of the nuclear energy and the fossil energies, the energy storage problems, the environmental and sanitary aspects, the energy mastership and economy. (A.L.B.)

A semi-physical simulation platform of attitude determination and control system for satellite

Directory of Open Access Journals (Sweden)

Yuanjin Yu

2016-05-01

Full Text Available A semi-physical simulation platform for attitude determination and control system is proposed to verify the attitude estimator and controller on ground. A simulation target, a host PC, many attitude sensors, and actuators compose the simulation platform. The simulation target is composed of a central processing unit board with VxWorks operating system and many input/output boards connected via Compact Peripheral Component Interconnect bus. The executable programs in target are automatically generated from the simulation models in Simulink based on Real-Time Workshop of MATLAB. A three-axes gyroscope, a three-axes magnetometer, a sun sensor, a star tracer, three flywheels, and a Global Positioning System receiver are connected to the simulation target, which formulates the attitude control cycle of a satellite. The simulation models of the attitude determination and control system are described in detail. Finally, the semi-physical simulation platform is used to demonstrate the availability and rationality of the control scheme of a micro-satellite. Comparing the results between the numerical simulation in Simulink and the semi-physical simulation, the semi-physical simulation platform is available and the control scheme successfully achieves three-axes stabilization.

Legal, ethical,and economic constraints

International Nuclear Information System (INIS)

Libassi, F.P.; Donaldson, L.F.

1980-01-01

This paper considers the legal, ethical, and economic constraints to developing a comprehensive knowledge of the biological effects of ionizing radiation. These constraints are not fixed and immutable; rather they are determined by the political process. Political issues cannot be evaded. The basic objective of developing a comprehensive knowledge about the biological effects of ionizing radiation exists as an objective not only because we wish to add to the store of human knowledge but also because we have important use for that knowledge. It will assist our decision-makers to make choices that affect us all. These choices require both hard factual information and application of political judgment. Research supplies some of the hard factual information and should be as free as possible from political influence in its execution. At the same time, the political choices that must be made influence the direction and nature of the research program as a whole. Similarly, the legal, ethical, and economic factors that constrain our ability to expand knowledge through research reflect a judgment by political agents that values other than expansion of knowledge should be recognized and given effect

Constraints on the CMB temperature-redshift dependence from SZ and distance measurements

Energy Technology Data Exchange (ETDEWEB)

Avgoustidis, A. [School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom); Luzzi, G. [Laboratoire de l' Accélérateur Linéaire, Université de Paris-Sud, CNRS/IN2P3, Bâtiment 200, BP 34, 91898 Orsay Cedex (France); Martins, C.J.A.P.; Monteiro, A.M.R.V.L., E-mail: A.Avgoustidis@damtp.cam.ac.uk, E-mail: gluzzi@lal.in2p3.fr, E-mail: Carlos.Martins@astro.up.pt, E-mail: up090322024@alunos.fc.up.pt [Centro de Astrofísica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal)

2012-02-01

The relation between redshift and the CMB temperature, T{sub CMB}(z) = T{sub 0}(1+z) is a key prediction of standard cosmology, but is violated in many non-standard models. Constraining possible deviations to this law is an effective way to test the ΛCDM paradigm and search for hints of new physics. We present state-of-the-art constraints, using both direct and indirect measurements. In particular, we point out that in models where photons can be created or destroyed, not only does the temperature-redshift relation change, but so does the distance duality relation, and these departures from the standard behaviour are related, providing us with an opportunity to improve constraints. We show that current datasets limit possible deviations of the form T{sub CMB}(z) = T{sub 0}(1+z){sup 1−β} to be β = 0.004±0.016 up to a redshift z ∼ 3. We also discuss how, with the next generation of space and ground-based experiments, these constraints can be improved by more than one order of magnitude.

Constraints on the CMB temperature-redshift dependence from SZ and distance measurements

International Nuclear Information System (INIS)

Avgoustidis, A.; Luzzi, G.; Martins, C.J.A.P.; Monteiro, A.M.R.V.L.

2012-01-01

The relation between redshift and the CMB temperature, T CMB (z) = T 0 (1+z) is a key prediction of standard cosmology, but is violated in many non-standard models. Constraining possible deviations to this law is an effective way to test the ΛCDM paradigm and search for hints of new physics. We present state-of-the-art constraints, using both direct and indirect measurements. In particular, we point out that in models where photons can be created or destroyed, not only does the temperature-redshift relation change, but so does the distance duality relation, and these departures from the standard behaviour are related, providing us with an opportunity to improve constraints. We show that current datasets limit possible deviations of the form T CMB (z) = T 0 (1+z) 1−β to be β = 0.004±0.016 up to a redshift z ∼ 3. We also discuss how, with the next generation of space and ground-based experiments, these constraints can be improved by more than one order of magnitude

Perceived Barriers to Healthy Eating and Physical Activity Among Participants in a Workplace Obesity Intervention.

Science.gov (United States)

Stankevitz, Kayla; Dement, John; Schoenfisch, Ashley; Joyner, Julie; Clancy, Shayna M; Stroo, Marissa; Østbye, Truls

2017-08-01

To characterize barriers to healthy eating (BHE) and physical activity (BPA) among participants in a workplace weight management intervention. Steps to health participants completed a questionnaire to ascertain barriers to physical activity and healthy eating faced. Exploratory factor analysis was used to determine the factor structure for BPA and BHE. The relationships of these factors with accelerometer data and dietary behaviors were assessed using linear regression. Barriers to physical activity included time constraints and lack of interest and motivation, and to healthy eating, lack of self-control and convenience, and lack of access to healthy foods. Higher BHE correlated with higher sugary beverage intake but not fruit and vegetable and fat intake. To improve their effectiveness, workplace weight management programs should consider addressing and reducing barriers to healthy eating and physical activity.

Evaluating Distributed Timing Constraints

DEFF Research Database (Denmark)

Kristensen, C.H.; Drejer, N.

1994-01-01

In this paper we describe a solution to the problem of implementing time-optimal evaluation of timing constraints in distributed real-time systems.......In this paper we describe a solution to the problem of implementing time-optimal evaluation of timing constraints in distributed real-time systems....

Thermomechanical constraints and constitutive formulations in thermoelasticity

Directory of Open Access Journals (Sweden)

Baek S.

2003-01-01

Full Text Available We investigate three classes of constraints in a thermoelastic body: (i a deformation-temperature constraint, (ii a deformation-entropy constraint, and (iii a deformation-energy constraint. These constraints are obtained as limits of unconstrained thermoelastic materials and we show that constraints (ii and (iii are equivalent. By using a limiting procedure, we show that for the constraint (i, the entropy plays the role of a Lagrange multiplier while for (ii and (iii, the absolute temperature plays the role of Lagrange multiplier. We further demonstrate that the governing equations for materials subject to constraint (i are identical to those of an unconstrained material whose internal energy is an affine function of the entropy, while those for materials subject to constraints (ii and (iii are identical to those of an unstrained material whose Helmholtz potential is affine in the absolute temperature. Finally, we model the thermoelastic response of a peroxide-cured vulcanizate of natural rubber and show that imposing the constraint in which the volume change depends only on the internal energy leads to very good predictions (compared to experimental results of the stress and temperature response under isothermal and isentropic conditions.

Atomic physics constraints on the X boson

Science.gov (United States)

Jentschura, Ulrich D.; Nándori, István

2018-04-01

Recently, a peak in the light fermion pair spectrum at invariant q2≈(16.7MeV ) 2 has been observed in the bombardment of 7Li by protons. This peak has been interpreted in terms of a protophobic interaction of fermions with a gauge boson (X boson) of invariant mass ≈16.7 MeV which couples mainly to neutrons. High-precision atomic physics experiments aimed at observing the protophobic interaction need to separate the X boson effect from the nuclear-size effect, which is a problem because of the short range of the interaction (11.8 fm), which is commensurate with a "nuclear halo." Here we analyze the X boson in terms of its consequences for both electronic atoms as well as muonic hydrogen and deuterium. We find that the most promising atomic systems where the X boson has an appreciable effect, distinguishable from a finite-nuclear-size effect, are muonic atoms of low and intermediate nuclear charge numbers.

Performance related factors are the main determinants of the von Willebrand factor response to exhaustive physical exercise

NARCIS (Netherlands)

J.E. van Loon (Janine ); M.A.H. Sonneveld (Michelle); S.F.E. Praet (Stephan); M.P.M. de Maat (Moniek); F.W.G. Leebeek (Frank)

2014-01-01

textabstractBackground: Physical stress triggers the endothelium to release von Willebrand Factor (VWF) from the Weibel Palade bodies. Since VWF is a risk factor for arterial thrombosis, it is of great interest to discover determinants of VWF response to physical stress. We aimed to determine the

Constraints on new physics from radiative B decays

Energy Technology Data Exchange (ETDEWEB)

Paul, Ayan [INFN, Sezione di Roma,I-00185 Rome (Italy); Straub, David M. [Excellence Cluster Universe, TUM,Boltzmannstr. 2, 85748 Garching (Germany)

2017-04-05

A new phase for the measurements of radiative decay modes in b→s transitions has started with new measurements of exclusive modes by LHCb and with Belle-II showing distinctive promises in both inclusive and exclusive channels. After critically reviewing the hadronic uncertainties in exclusive radiative decays, we analyze the impact of recent measurements of the branching ratio and mass-eigenstate rate asymmetry in B{sub s}→ϕγ and of the angular distribution of B→K{sup ∗}e{sup +}e{sup −} at low q{sup 2} on new physics in the b→sγ transition.

ELMs and constraints on the H-mode pedestal: A model based on peeling-ballooning modes

International Nuclear Information System (INIS)

Snyder, P.B.

2002-01-01

Maximizing the pedestal height while maintaining acceptable ELMs is a key issue for optimizing tokamak performance. We present a model for ELMs and pedestal constraints based upon theoretical analysis of edge instabilities which can limit the pedestal height and drive ELMs. Sharp pedestal pressure gradients drive large bootstrap currents which play a complex dual role in the stability physics. Consequently, the dominant modes are often intermediate-n coupled 'peeling-ballooning' modes, driven both by current and the pressure gradient. A highly efficient new MHD code, ELITE, is used to study these modes, and calculate quantitative stability constraints on the pedestal, including direct constraints on the pedestal height. A model of various ELM types is developed, and quantitatively compared to data from several tokamaks. A number of observations agree with predictions, including ELM onset times, ELM depth, and variation in pedestal height with discharge shape. Projections of pedestal stability constraints for Next Step designs, and nonlinear simulations of peeling-ballooning modes using the BOUT code are also presented. (author)

Machine tongues. X. Constraint languages

Energy Technology Data Exchange (ETDEWEB)

Levitt, D.

Constraint languages and programming environments will help the designer produce a lucid description of a problem domain, and then of particular situations and problems in it. Early versions of these languages were given descriptions of real world domain constraints, like the operation of electrical and mechanical parts. More recently, the author has automated a vocabulary for describing musical jazz phrases, using constraint language as a jazz improviser. General constraint languages will handle all of these domains. Once the model is in place, the system will connect built-in code fragments and algorithms to answer questions about situations; that is, to help solve problems. Bugs will surface not in code, but in designs themselves. 15 references.

Constraints of philanthropy on determining the distribution of biodiversity conservation funding.

Science.gov (United States)

Larson, Eric R; Howell, Stephen; Kareiva, Peter; Armsworth, Paul R

2016-02-01

Caught between ongoing habitat destruction and funding shortfalls, conservation organizations are using systematic planning approaches to identify places that offer the highest biodiversity return per dollar invested. However, available tools do not account for the landscape of funding for conservation or quantify the constraints this landscape imposes on conservation outcomes. Using state-level data on philanthropic giving to and investments in land conservation by a large nonprofit organization, we applied linear regression to evaluate whether the spatial distribution of conservation philanthropy better explained expenditures on conservation than maps of biodiversity priorities, which were derived from a planning process internal to the organization and return on investment (ROI) analyses based on data on species richness, land costs, and existing protected areas. Philanthropic fund raising accounted for considerably more spatial variation in conservation spending (r(2) = 0.64) than either of the 2 systematic conservation planning approaches (r(2) = 0.08-0.21). We used results of one of the ROI analyses to evaluate whether increases in flexibility to reallocate funding across space provides conservation gains. Small but plausible "tax" increments of 1-10% on states redistributed to the optimal funding allocation from the ROI analysis could result in gains in endemic species protected of 8.5-80.2%. When such increases in spatial flexibility are not possible, conservation organizations should seek to cultivate increased support for conservation in priority locations. We used lagged correlations of giving to and spending by the organization to evaluate whether investments in habitat protection stimulate future giving to conservation. The most common outcome at the state level was that conservation spending quarters correlated significantly and positively with lagged fund raising quarters. In effect, periods of high fund raising for biodiversity followed (rather than

Determinants of meeting the public health recommendations for physical activity among community-dwelling elderly Japanese.

Science.gov (United States)

Oka, Koichiro; Shibata, Ai

2012-02-01

Although regular physical activity can facilitate healthy aging, improve functional capacity, and prevent chronic diseases in the elderly, many of the Japanese elderly are not sufficiently active. Thus, examining the determinants is an important prerequisite for designing effective programs. The present study investigated the demographic, behavioral, psychosocial, and environmental determinants of meeting the national pedometer-determined physical activity recommendations for the elderly Japanese. Data were analyzed for 137 community-dwelling elderly Japanese aged 70 to 89 years (47% male, mean age = 74.5 years), who completed a questionnaire and wore a pedometer. Demographic (gender, age, marital status), behavioral (BMI, smoking, alcohol consumption), psychosocial (self-efficacy, social support, health professional advice), and environmental (perceived neighborhood environment) variables were self-reported. Averaged daily steps were obtained using 1-year pedometer measurements. Based on the national physical activity recommendations in Japan (males: 6700 steps; females: 5900 steps), the participants were divided into two categories - sufficiently active and insufficiently active. An adjusted logistic regression model was utilized. Totally, 47.4% of the participants (males: 51.5%; females: 43.8%) met the national recommendations. When adjusting for all other variables, a higher self-efficacy for exercise (AOR = 1.16; 95% CI: 1.04-1.28) and positive perception of the neighborhood environment (AOR = 1.43; 95% CI: 1.03-1.98) significantly influenced the meeting of the national recommendations. The findings clarified the need to identify effective intervention strategies to promote physical activity and suggest that an intervention design that accounts for these determinants may more effectively promote physical activity among the elderly Japanese.

Reduction of physical activity in daily life and its determinants in smokers without airflow obstruction.

Science.gov (United States)

Furlanetto, Karina Couto; Mantoani, Leandro Cruz; Bisca, Gianna; Morita, Andrea Akemi; Zabatiero, Juliana; Proença, Mahara; Kovelis, Demétria; Pitta, Fabio

2014-04-01

In smokers without airflow obstruction, detailed, objective and controlled quantification of the level of physical inactivity in daily life has never been performed. This study aimed to objectively assess the level of physical activity in daily life in adult smokers without airflow obstruction in comparison with matched non-smokers, and to investigate the determinants for daily physical activity in smokers. Sixty smokers (aged 50 (39-54) years) and 50 non-smokers (aged 48 (40-53) years) matched for gender, age, anthropometric characteristics, educational level, employment status and seasons of the year assessment period were cross-sectionally assessed regarding their daily physical activity with a step counter, besides assessment of lung function, functional exercise capacity, quality of life, anxiety, depression, self-reported comorbidities carbon monoxide level, nicotine dependence and smoking habits. When compared with non-smokers, smokers walked less in daily life (7923 ± 3558 vs 9553 ± 3637 steps/day, respectively), presented worse lung function, functional exercise capacity, quality of life, anxiety and depression. Multiple regression analyses identified functional exercise capacity, Borg fatigue, self-reported motivation/physical activity behaviour and cardiac disease as significant determinants of number of steps/day in smokers (partial r(2)  = 0.10, 0.12, 0.16 and 0.05; b = 15, -997, 1207 and -2330 steps/day, respectively; overall fit of the model R(2)  = 0.38; P smokers without airflow obstruction presented reduced level of daily physical activity. Functional exercise capacity, extended fatigue sensation, aspects of motivation/physical activity behaviour and self-reported cardiac disease are significant determinants of physical activity in daily life in smokers. © 2014 The Authors. Respirology © 2014 Asian Pacific Society of Respirology.

Physics design of fast reactor safety test facilities for in-pile experiments

International Nuclear Information System (INIS)

Travelli, A.; Matos, J.E.; Snelgrove, J.L.; Shaftman, D.H.; Tzanos, C.P.; Lam, S.K.; Pennington, E.M.; Woodruff, W.L.

1976-01-01

A determined effort to identify and resolve current Fast Breeder Reactor safety testing needs has recently resulted in a number of conceptual designs for FBR safety test facilities which are very complex and diverse both in their features and in their purpose. The paper discusses the physics foundations common to most fast reactor safety test facilities and the constraints which they impose on the design. The logical evolution, features, and capabilities of several major conceptual designs are discussed on the basis of this common background

Perceived teaching behaviors and self-determined motivation in physical education: a test of self-determination theory.

Science.gov (United States)

Koka, Andre; Hagger, Martin S

2010-03-01

In the present study, we tested the effects of specific dimensions of perceived teaching behaviors on students' self-determined motivation in physical education. In accordance with the tenets of self-determination theory (Deci & Ryan, 1985, 2000), we expected the psychological needs for competence, autonomy, and relatedness would mediate these effects. Secondary school students (N=498) ages 12-17 years completed measures of perceived teaching behaviors for seven dimensions: (a) democratic behavior, (b) autocratic behavior (c) teaching and instruction, (d) situation consideration, (e) positive general feedback, (f) positive nonverbal feedback, and (h) negative nonverbal feedback. They also completed measures of perceived satisfaction for competence, autonomy, relatedness, and self-determined motivation. A path-analytic model revealed a positive, indirect effect of perceived positive general feedback on self-determined motivation. The effects of perceived autocratic behavior and negative nonverbal feedback were direct and negative, whereas the effects of teaching and instruction and situation consideration were direct and positive. Results suggest that feedback, situation consideration, and teaching and instruction are essential antecedents to self-determined motivation.

Micro-compression testing: A critical discussion of experimental constraints

International Nuclear Information System (INIS)

Kiener, D.; Motz, C.; Dehm, G.

2009-01-01

Micro-compression testing is a promising technique for determining mechanical properties at small length scales since it has several benefits over nanoindentation. However, as for all new techniques, experimental constraints influencing the results of such a micro-mechanical test must be considered. Here we investigate constraints imposed by the sample geometry, the pile-up of dislocations at the sample top and base, and the lateral stiffness of the testing setup. Using a focused ion beam milling setup, single crystal Cu specimens with different geometries and crystal orientations were fabricated. Tapered samples served to investigate the influence of strain gradients, while stiff sample top coatings and undeformable substrates depict the influence of dislocation pile-ups at these interfaces. The lateral system stiffness was reduced by placing specimens on top of needles. Samples were loaded using an in situ indenter in a scanning electron microscope in load controlled or displacement controlled mode. The observed differences in the mechanical response with respect to the experimental imposed constraints are discussed and lead to the conclusion that controlling the lateral system stiffness is the most important point

Self-determined Engagement in Physical Activity and Sedentary Behaviors of US College Students

OpenAIRE

QUARTIROLI, ALESSANDRO; MAEDA, HOTAKA

2014-01-01

Although the importance of promoting physical activity is well established, researchers have recently considered ?sedentary behaviors? as another key risk factor for chronic disease. However, little is known about the motivational processes regulating sedentary behavior on a daily basis. A substantial amount of research has been based on the self-determination theory to examine the motivational processes regulating physical activity behaviors. However, only limited attention has been paid to ...

An effective heuristic for combined heat-and-power production planning with power ramp constraints

International Nuclear Information System (INIS)

Rong, Aiying; Lahdelma, Risto

2007-01-01

Combined heat-and-power (CHP) production is an increasingly important technology for its efficient utilization of primary-energy resources and for reducing CO 2 emissions. In the CHP plant, the generation of heat-and-power follows a joint characteristic, which makes the determination of both the marginal power production cost (MPPC) and the feasible operating region for the plant more complicated than for the power-only generation plant. Due to the interdependence between heat and power production, the power-ramp constraints, which limit how much the power production of a CHP plant may increase or decrease between two successive periods, may also imply constraints on the heat production. In this paper, we investigate the impact of power-ramp constraints on CHP production planning and develop a robust heuristic for dealing with the power-ramp constraints based on the solution to the problem with relaxed ramp-constraints (RRC). Numerical results based on realistic production models show that the heuristic can generate high-quality solutions efficiently. (author)

Ant colony optimization and constraint programming

CERN Document Server

Solnon, Christine

2013-01-01

Ant colony optimization is a metaheuristic which has been successfully applied to a wide range of combinatorial optimization problems. The author describes this metaheuristic and studies its efficiency for solving some hard combinatorial problems, with a specific focus on constraint programming. The text is organized into three parts. The first part introduces constraint programming, which provides high level features to declaratively model problems by means of constraints. It describes the main existing approaches for solving constraint satisfaction problems, including complete tree search

How robust are inflation model and dark matter constraints from cosmological data?

International Nuclear Information System (INIS)

Hamann, J.; Hannestad, S.; Sloth, M.S.; Wong, Y.Y.Y.

2006-11-01

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 ΛCDM models, the simple λφ 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 τ and the neutrino mass prevents λφ 4 from being excluded by present data. Reversing the argument, if λφ 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 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 c h 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.)

Least Squares Problems with Absolute Quadratic Constraints

Directory of Open Access Journals (Sweden)

R. Schöne

2012-01-01

Full Text Available This paper analyzes linear least squares problems with absolute quadratic constraints. We develop a generalized theory following Bookstein's conic-fitting and Fitzgibbon's direct ellipse-specific fitting. Under simple preconditions, it can be shown that a minimum always exists and can be determined by a generalized eigenvalue problem. This problem is numerically reduced to an eigenvalue problem by multiplications of Givens' rotations. Finally, four applications of this approach are presented.

Causality Constraints in Conformal Field Theory

CERN Multimedia

CERN. Geneva

2015-01-01

Causality places nontrivial constraints on QFT in Lorentzian signature, for example fixing the signs of certain terms in the low energy Lagrangian. In d-dimensional conformal field theory, we show how such constraints are encoded in crossing symmetry of Euclidean correlators, and derive analogous constraints directly from the conformal bootstrap (analytically). The bootstrap setup is a Lorentzian four-point function corresponding to propagation through a shockwave. Crossing symmetry fixes the signs of certain log terms that appear in the conformal block expansion, which constrains the interactions of low-lying operators. As an application, we use the bootstrap to rederive the well known sign constraint on the (∂φ)4 coupling in effective field theory, from a dual CFT. We also find constraints on theories with higher spin conserved currents. Our analysis is restricted to scalar correlators, but we argue that similar methods should also impose nontrivial constraints on the interactions of spinni...

Causality constraints in conformal field theory

Energy Technology Data Exchange (ETDEWEB)

Hartman, Thomas; Jain, Sachin; Kundu, Sandipan [Department of Physics, Cornell University,Ithaca, New York (United States)

2016-05-17

Causality places nontrivial constraints on QFT in Lorentzian signature, for example fixing the signs of certain terms in the low energy Lagrangian. In d dimensional conformal field theory, we show how such constraints are encoded in crossing symmetry of Euclidean correlators, and derive analogous constraints directly from the conformal bootstrap (analytically). The bootstrap setup is a Lorentzian four-point function corresponding to propagation through a shockwave. Crossing symmetry fixes the signs of certain log terms that appear in the conformal block expansion, which constrains the interactions of low-lying operators. As an application, we use the bootstrap to rederive the well known sign constraint on the (∂ϕ){sup 4} coupling in effective field theory, from a dual CFT. We also find constraints on theories with higher spin conserved currents. Our analysis is restricted to scalar correlators, but we argue that similar methods should also impose nontrivial constraints on the interactions of spinning operators.

Observational Constraints for Modeling Diffuse Molecular Clouds

Science.gov (United States)

Federman, S. R.

2014-02-01

Ground-based and space-borne observations of diffuse molecular clouds suggest a number of areas where further improvements to modeling efforts is warranted. I will highlight those that have the widest applicability. The range in CO fractionation caused by selective isotope photodissociation, in particular the large 12C16O/13C16O ratios observed toward stars in Ophiuchus, is not reproduced well by current models. Our ongoing laboratory measurements of oscillator strengths and predissociation rates for Rydberg transitions in CO isotopologues may help clarify the situtation. The CH+ abundance continues to draw attention. Small scale structure seen toward ζ Per may provide additional constraints on the possible synthesis routes. The connection between results from optical transitions and those from radio and sub-millimeter wave transitions requires further effort. A study of OH+ and OH toward background stars reveals that these species favor different environments. This brings to focus the need to model each cloud along the line of sight separately, and to allow the physical conditions to vary within an individual cloud, in order to gain further insight into the chemistry. Now that an extensive set of data on molecular excitation is available, the models should seek to reproduce these data to place further constraints on the modeling results.

Engineering design constraints of the lunar surface environment

Science.gov (United States)

Morrison, D. A.

1992-01-01

Living and working on the lunar surface will be difficult. Design of habitats, machines, tools, and operational scenarios in order to allow maximum flexibility in human activity will require paying attention to certain constraints imposed by conditions at the surface and the characteristics of lunar material. Primary design drivers for habitat, crew health and safety, and crew equipment are: ionizing radiation, the meteoroid flux, and the thermal environment. Secondary constraints for engineering derive from: the physical and chemical properties of lunar surface materials, rock distributions and regolith thicknesses, topography, electromagnetic properties, and seismicity. Protection from ionizing radiation is essential for crew health and safety. The total dose acquired by a crew member will be the sum of the dose acquired during EVA time (when shielding will be least) plus the dose acquired during time spent in the habitat (when shielding will be maximum). Minimizing the dose acquired in the habitat extends the time allowable for EVA's before a dose limit is reached. Habitat shielding is enabling, and higher precision in predicting secondary fluxes produced in shielding material would be desirable. Means for minimizing dose during a solar flare event while on extended EVA will be essential. Early warning of the onset of flare activity (at least a half-hour is feasible) will dictate the time available to take mitigating steps. Warning capability affects design of rovers (or rover tools) and site layout. Uncertainty in solar flare timing is a design constraint that points to the need for quickly accessible or constructible safe havens.

Learning and Parallelization Boost Constraint Search

Science.gov (United States)

Yun, Xi

2013-01-01

Constraint satisfaction problems are a powerful way to abstract and represent academic and real-world problems from both artificial intelligence and operations research. A constraint satisfaction problem is typically addressed by a sequential constraint solver running on a single processor. Rather than construct a new, parallel solver, this work…

Fuzzy Constraint-Based Agent Negotiation

Institute of Scientific and Technical Information of China (English)

Menq-Wen Lin; K. Robert Lai; Ting-Jung Yu

2005-01-01

Conflicts between two or more parties arise for various reasons and perspectives. Thus, resolution of conflicts frequently relies on some form of negotiation. This paper presents a general problem-solving framework for modeling multi-issue multilateral negotiation using fuzzy constraints. Agent negotiation is formulated as a distributed fuzzy constraint satisfaction problem (DFCSP). Fuzzy constrains are thus used to naturally represent each agent's desires involving imprecision and human conceptualization, particularly when lexical imprecision and subjective matters are concerned. On the other hand, based on fuzzy constraint-based problem-solving, our approach enables an agent not only to systematically relax fuzzy constraints to generate a proposal, but also to employ fuzzy similarity to select the alternative that is subject to its acceptability by the opponents. This task of problem-solving is to reach an agreement that benefits all agents with a high satisfaction degree of fuzzy constraints, and move towards the deal more quickly since their search focuses only on the feasible solution space. An application to multilateral negotiation of a travel planning is provided to demonstrate the usefulness and effectiveness of our framework.

Constraint-based scheduling

Science.gov (United States)

Zweben, Monte

1993-01-01

The GERRY scheduling system developed by NASA Ames with assistance from the Lockheed Space Operations Company, and the Lockheed Artificial Intelligence Center, uses a method called constraint-based iterative repair. Using this technique, one encodes both hard rules and preference criteria into data structures called constraints. GERRY repeatedly attempts to improve schedules by seeking repairs for violated constraints. The system provides a general scheduling framework which is being tested on two NASA applications. The larger of the two is the Space Shuttle Ground Processing problem which entails the scheduling of all the inspection, repair, and maintenance tasks required to prepare the orbiter for flight. The other application involves power allocation for the NASA Ames wind tunnels. Here the system will be used to schedule wind tunnel tests with the goal of minimizing power costs. In this paper, we describe the GERRY system and its application to the Space Shuttle problem. We also speculate as to how the system would be used for manufacturing, transportation, and military problems.

Pramana – Journal of Physics | Indian Academy of Sciences

Indian Academy of Sciences (India)

The working group on astroparticle and neutrino physics at WHEPP-9 covered a wide range of topics. The main topics were neutrino physics at INO, neutrino astronomy and recent constraints on dark energy coming from cosmological observations of large scale structure and CMB anisotropy.

Relaxation of the lower frit loading constraint for DWPF process control

International Nuclear Information System (INIS)

Brown, K.G.

2000-01-01

The lower limit on the frit loading parameter when measurement uncertainty is introduced has impacted DWPF performance during immobilization of Tank 42 Sludge; therefore, any defensible relaxation or omission of this constraint should correspondingly increase DWPF waste loading and efficiency. Waste loading should be increased because the addition of frit is the current remedy for exceeding the lower frit loading constraint. For example, frit was added to DWPF SME Batches 94, 97 and 98 to remedy these batches for low frit loading. Attempts were also made to add frit in addition to the optimum computed to assure the lower frit loading constraint would be satisfied; however, approximately half of the SME Batches produced after Batch 98 have violated the lower frit loading constraint. If the DWPF batches did not have to be remediated and additional frit added because of the lower frit loading limit, then both, the performance of the DWPF process and the waste loading in the glass produced would be increased. Before determining whether or not the lower frit loading limit can be relaxed or omitted, the origin of this and the other constraints related to durability prediction must be examined. The lower limit loading constraint results from the need to make highly durable glass in DWPF. It is required that DWPF demonstrate that the glass produced would have durability that is at least two standard deviations greater than that of the Environmental Assessment (EA) glass. Glass durability cannot be measured in situ, it must be predicted from composition which can be measured. Fortunately, the leaching characteristics of homogeneous waste glasses is strongly related to the total molar free energy of the constituent species. Thus the waste acceptance specification has been translated into a requirement that the total molar free energy associated with the glass composition that would be produced from a DWPF melter feed batch be less than that of the EA glass accounting for

Risk constraint measures developed for the outcome-based strategy for tank waste management

International Nuclear Information System (INIS)

Harper, B.L.; Gajewski, S.J.; Glantz, C.L.

1996-09-01

This report is one of a series of supporting documents for the outcome-based characterization strategy developed by PNNL. This report presents a set of proposed risk measures with risk constraint (acceptance) levels for use in the Value of Information process used in the NCS. The characterization strategy has developed a risk-based Value of Information (VOI) approach for comparing the cost-effectiveness of characterizing versus mitigating particular waste tanks or tank clusters. The preference between characterizing or mitigating in order to prevent an accident depends on the cost of those activities relative to the cost of the consequences of the accident. The consequences are defined as adverse impacts measured across a broad set of risk categories such as worker dose, public cancers, ecological harm, and sociocultural impacts. Within each risk measure, various open-quotes constraint levelsclose quotes have been identified that reflect regulatory standards or conventionally negotiated thresholds of harm to Hanford resources and values. The cost of consequences includes the open-quotes costs close-quote of exceeding those constraint levels as well as a strictly linear costing per unit of impact within each of the risk measures. In actual application, VOI based-decision making is an iterative process, with a preliminary low-precision screen of potential technical options against the major risk constraints, followed by VOI analysis to determine the cost-effectiveness of gathering additional information and to select a preferred technical option, and finally a posterior screen to determine whether the preferred option meets all relevant risk constraints and acceptability criteria

Determinants of dietary behavior and physical activity among Canadian Inuit: a systematic review.

Science.gov (United States)

Akande, Victor O; Hendriks, Anna M; Ruiter, Robert A C; Kremers, Stef P J

2015-06-24

Increased dependence on Western diets and low physical activity have largely contributed to weight gain and associated chronic diseases in the Canadian Inuit population. The purpose of this study was to systematically review factors influencing dietary and physical activity behaviors to guide health promotion interventions and provide recommendations for future studies. We conducted a systematic literature review to identify relevant articles. Searches were conducted between May 2014 and July 2014, and inclusive of articles published up until July 2014. Articles were searched using four databases: PubMed, PsycINFO, SocINDEX, and Psychology and Behavioral Sciences Collection. Eligible studies focused on diet and/or physical activity or determinants of diet and/or physical activity in Canadian Inuit population, and were published in English. A total of 45 articles were included in the analysis. A detailed appraisal of the articles suggested that many Inuit have disconnected from the traditional ways of life, including harvesting and processing of traditional food species and the associated physical activity. In the last two decades there has been a significant shift from consumption of healthy traditional foods to energy-dense store-bought foods particularly among younger Inuit (Inuit. However, our understanding is limited on how these behaviours might be influenced in the face of these changes. Prospective studies are needed to advance our knowledge of cognitive and environmental determinants of Inuit energy balance-related behaviours. These studies can inform the development of health promotion interventions in the population.

SYMMETRIC DETERMINATION OF THE SEVERITY OF PRODUCTIVITY CONSTRAINTS OF FISH FARMERS IN THE TROPICS: A CASE STUDY OF THE NIGER DELTA REGION, NIGERIA

Directory of Open Access Journals (Sweden)

VALERIE Solomon

2001-09-01

Full Text Available The study was conducted to fi ll the gap in the dearth of information on systematic approach to ascertain the severity as well as the magnitude of the constraints responsible for the sub-optimal operation of fi sh farming in Nigeria. 120 randomly selected fish farmers from a list of 186 fi sh farmers in the state were interviewed. Participatory appraisal technique and econometric technique were adopted to ascertain the most severe major constraints and also the severity index of each of the sub-constraints that are responsible for the sub-optimal aquaculture operation in the Niger Delta region of Nigeria and the cause of withdrawal from aquaculture by some fi sh farmers. The sub-constraints severity within the major constraints, across the region gave more insight into the causes of the high rate of withdrawals from aquaculture and the decline in aquaculture productivity in the region. How productive the regional aquaculture would be, even in the nearest future, would depend to a large extent on these major factors: production, marketing and advancement in related technology. Unless pragmatic approach is used to reduce the constraints responsible for the high rate of withdrawal, fi sh food security in the Niger Delta Region of Nigeria would still be elusive.

The energy in all states: data, constraints, stakes; L'energie sous toutes ses formes: donnees, contraintes, enjeux

Energy Technology Data Exchange (ETDEWEB)

Balian, R. [Academie des Sciences, 92 - Gif sur Yvette (France); Combarnous, M. [Bordeaux-1 Univ., LEPT-ENSAM, 33 - Talence (France); Lucas, J.; Fauvarque, J.F. [Conservatoire National des Arts et Metiers (CNAM), 75 - Paris (France); Madet, D. [Electricite de France (EDF), 75 - Paris (France); Bal, J.L. [Agence de l' Environnement et de la Maitrise de l' Energie, ADEME, 75 - Paris (France); Jourde, P. [CEA Cadarache, GENEC, 13 - Saint-Paul-lez-Durance (France); Tissot, B. [Commission Nationale d' Evaluation, 75 - Paris (France); Leconte, Ph. [CEA Saclay, Dir. du Developpement et de l' Innovation Nucleares DDIN, 91 - Gif Sur Yvette (France); Doubre, H. [Paris-11 Univ., IN2P3/CNRS, 91 - Orsay (France); Alleau, Th. [Association Francaise de l' Hydrogene, AFH2, 75 - Paris (France); Durup, G. [Mining Research Institute (United States); Le Treut, H. [Ecole Nationale Superieure, 75 - Paris (France); Tubiana, M. [Institut Gustave Roussy, 94 - Villejuif (France)]|[Centre Antoine Beclere, Paris (France); Masse, R. [Office de Protection contre les Rayonnements Ionisants, 78 - le Vesinet (France); Lebot, B. [Agence Internationale de l' Energie, 75 - Paris (France); Babusiaux, D. [Institut Francais du Petrole (IFP), 92 - Rueil-Malmaison (France); Saab, A.E. [Electricite de France (EDF), 75 - Paris (France)

2002-07-01

This documents brings together papers presented at the physics summer school of august 2001 on the energy. The following topics are discussed: the constraints bound to the physics and the scales, the renewable energies, the future of the nuclear energy and the fossil energies, the energy storage problems, the environmental and sanitary aspects, the energy mastership and economy. (A.L.B.)

Statistical quality analysis of schedulers under soft-real-time constraints

NARCIS (Netherlands)

Baarsma, H.E.; Hurink, Johann L.; Jansen, P.G.

2007-01-01

This paper describes an algorithm to determine the performance of real-time systems with tasks using stochastic processing times. Such an algorithm can be used for guaranteeing Quality of Service of periodic tasks with soft real-time constraints. We use a discrete distribution model of processing

Precision constraints on the top-quark effective field theory at future lepton colliders

Energy Technology Data Exchange (ETDEWEB)

Durieux, Gauthier

2017-08-15

We examine the constraints that future lepton colliders would impose on the effective field theory describing modifications of top-quark interactions beyond the standard model, through measurements of the e{sup +}e{sup -}→bW{sup +} anti bW{sup -} process. Statistically optimal observables are exploited to constrain simultaneously and efficiently all relevant operators. Their constraining power is sufficient for quadratic effective-field-theory contributions to have negligible impact on limits which are therefore basis independent. This is contrasted with the measurements of cross sections and forward-backward asymmetries. An overall measure of constraints strength, the global determinant parameter, is used to determine which run parameters impose the strongest restriction on the multidimensional effective-field-theory parameter space.

Precision constraints on the top-quark effective field theory at future lepton colliders

International Nuclear Information System (INIS)

Durieux, Gauthier

2017-08-01

We examine the constraints that future lepton colliders would impose on the effective field theory describing modifications of top-quark interactions beyond the standard model, through measurements of the e + e - →bW + anti bW - process. Statistically optimal observables are exploited to constrain simultaneously and efficiently all relevant operators. Their constraining power is sufficient for quadratic effective-field-theory contributions to have negligible impact on limits which are therefore basis independent. This is contrasted with the measurements of cross sections and forward-backward asymmetries. An overall measure of constraints strength, the global determinant parameter, is used to determine which run parameters impose the strongest restriction on the multidimensional effective-field-theory parameter space.

Possible cosmogenic neutrino constraints on Planck-scale Lorentz violation

Energy Technology Data Exchange (ETDEWEB)

Mattingly, David M. [New Hamshire Univ., Durham, NH (United States); Maccione, Luca [DESY Hamburg (Germany). Theory Group; Galaverni, Matteo [INAF-IASF Bologna (Italy); Liberati, Stefano [INFN, Trieste (Italy); SISSA, Trieste (Italy); Sigl, Guenter [Hamburg Univ. (Germany). II. Inst. fuer Theoretische Physik

2009-11-15

We study, within an effective field theory framework, O(E{sup 2}/M{sup 2}{sub Pl}) Planck-scale suppressed Lorentz invariance violation (LV) effects in the neutrino sector, whose size we parameterize by a dimensionless parameter {eta}{sub {nu}}. We find deviations from predictions of Lorentz invariant physics in the cosmogenic neutrino spectrum. For positive O(1) coefficients no neutrino will survive above 10{sup 19} eV. The existence of this cutoff generates a bump in the neutrino spectrum at energies of 10{sup 17} eV. Although at present no constraint can be cast, as current experiments do not have enough sensitivity to detect ultra-high-energy neutrinos, we show that experiments in construction or being planned have the potential to cast limits as strong as {eta}{sub {nu}} Constraints on {eta}{sub {nu}}<0 can in principle be obtained with this strategy, but they require a more detailed modeling of how LV affects the neutrino sector. (orig.)

Do older adults perceive postural constraints for reach estimation?

Science.gov (United States)

Cordova, Alberto; Gabbard, Carl

2014-01-01

BACKGROUND/STUDY CONTEXT: Recent evidence indicates that older persons have difficulty mentally representing intended movements. Furthermore, in an estimation of reach paradigm using motor imagery, a form of mental representation, older persons significantly overestimated their ability compared with young adults. The authors tested the notion that older adults may also have difficulty perceiving the postural constraints associated with reach estimation. The authors compared young (Mage = 22 years) and older (Mage = 67) adults on reach estimation while seated and in a more postural demanding standing and leaning forward position. The expectation was a significant postural effect with the standing condition, as evidenced by reduced overestimation. Whereas there was no difference between groups in the seated condition (both overestimated), older adults underestimated whereas the younger group once again overestimated in the standing condition. From one perspective, these results show that older adults do perceive postural constraints in light of their own physical capabilities. That is, that group perceived greater postural demands with the standing posture and elected to program a more conservative strategy, resulting in underestimation.

Possible cosmogenic neutrino constraints on Planck-scale Lorentz violation

International Nuclear Information System (INIS)

Mattingly, David M.; Maccione, Luca; Galaverni, Matteo; Liberati, Stefano; Sigl, Günter

2010-01-01

We study, within an effective field theory framework, O(E 2 M Pl 2 ) Planck-scale suppressed Lorentz invariance violation (LV) effects in the neutrino sector, whose size we parameterize by a dimensionless parameter η ν . We find deviations from predictions of Lorentz invariant physics in the cosmogenic neutrino spectrum. For positive O(1) coefficients no neutrino will survive above 10 19 eV. The existence of this cutoff generates a bump in the neutrino spectrum at energies of 10 17 eV. Although at present no constraint can be cast, as current experiments do not have enough sensitivity to detect ultra-high-energy neutrinos, we show that experiments in construction or being planned have the potential to cast limits as strong as η ν ∼ −4 on the neutrino LV parameter, depending on how LV is distributed among neutrino mass states. Constraints on η ν < 0 can in principle be obtained with this strategy, but they require a more detailed modeling of how LV affects the neutrino sector

How energetic and environmental constraints of microorganisms determine the carbon turnover in soils

Science.gov (United States)

Don, A.; Rödenbeck, C.; Gleixner, G.

2012-04-01

Microorganisms are the main catalysts driving carbon fluxes from soils. Traditional concepts of soil carbon stabilization failed to account for environmental and energy constraints of microorganisms. The distribution and density of organic carbon in the soil profile maybe a key factor determining the carbon stability and carbon flux. Decomposition is a two-step process following the Michaelis Menten kinetics: In a first step enzyme and substrate form a joint complex and then the decomposition reaction is catalyzed. Thus, biological decomposition relies on the encounter of substrate and the degradation catalyst, the microorganisms. Lower substrate concentration decreases the likelihood of an enzyme to hit a substrate molecule, to form an enzyme-substrate complex, and thus to catalyze the reaction. However, it was unproofen if this concept can be appliued to soils also. A long-term lab experiment revealed that the soil carbon turnover decreased with increasing carbon dilution due to mixture with soil minerals. The ability of microorganisms to move towards substrate in soils seems to be limited. To elucidate the effect of concentration-controlled carbon turnover, we devised the simple simulation model SCAMP based on the two-step kinetic with microorganism and carbon particles been simulated explicitly. The SCAMP model was able to simulate soil carbon profiles and age profiles in a realistic manner. The only carbon stabilization mechanism implemented in the model is the distribution of microorganisms and carbon particles in the soil and thus the availability of carbon for microorganism, which is especially important for subsoil carbon dynamics. The experiments and the model help to explain why large fractions of soil carbon have been stabilized for millennia and decoupled from the global carbon cycle.

Constraint satisfaction problems with isolated solutions are hard

International Nuclear Information System (INIS)

Zdeborová, Lenka; Mézard, Marc

2008-01-01

We study the phase diagram and the algorithmic hardness of the random 'locked' constraint satisfaction problems, and compare them to the commonly studied 'non-locked' problems like satisfiability of Boolean formulae or graph coloring. The special property of the locked problems is that clusters of solutions are isolated points. This simplifies significantly the determination of the phase diagram, which makes the locked problems particularly appealing from the mathematical point of view. On the other hand, we show empirically that the clustered phase of these problems is extremely hard from the algorithmic point of view: the best known algorithms all fail to find solutions. Our results suggest that the easy/hard transition (for currently known algorithms) in the locked problems coincides with the clustering transition. These should thus be regarded as new benchmarks of really hard constraint satisfaction problems

Notes on Timed Concurrent Constraint Programming

DEFF Research Database (Denmark)

Nielsen, Mogens; Valencia, Frank D.

2004-01-01

and program reactive systems. This note provides a comprehensive introduction to the background for and central notions from the theory of tccp. Furthermore, it surveys recent results on a particular tccp calculus, ntcc, and it provides a classification of the expressive power of various tccp languages.......A constraint is a piece of (partial) information on the values of the variables of a system. Concurrent constraint programming (ccp) is a model of concurrency in which agents (also called processes) interact by telling and asking information (constraints) to and from a shared store (a constraint...

Intrapersonal, social and physical environmental determinants of moderate-to-vigorous physical activity in working-age women: a systematic review protocol.

Science.gov (United States)

Prince, Stephanie A; Reed, Jennifer L; Nerenberg, Kara A; Kristjansson, Elizabeth A; Hiremath, Swapnil; Adamo, Kristi B; Tulloch, Heather E; Mullen, Kerri-Anne; Fodor, J George; Wright, Erica; Reid, Robert D

2014-11-04

The majority of North American adult females do not meet current physical activity recommendations (150 min of moderate-to-vigorous intensity physical activity (MVPA) per week accrued in ≥10 min bouts) ultimately placing themselves at increased risk of morbidity and mortality. Working-age females face particular challenges in meeting physical activity recommendations as they have multiple demands, including occupational, family and social demands. To develop effective interventions to increase MVPA among working-age females, it is necessary to identify and understand the strongest modifiable determinants influencing these behaviours. Therefore, the objective of this systematic review is to examine the available evidence to identify intrapersonal, social and environmental determinants of MVPA among working-age females. Six electronic databases will be searched to identify all prospective cohort studies that report on intrapersonal, social and/or environmental determinants of MVPA in working-age females. Grey literature sources including theses, published conference abstracts and websites from relevant organizations will also be included. Articles that report on intrapersonal (e.g. health status, self-efficacy, socio-economic status (SES), stress, depression), social environmental (e.g. crime, safety, area SES, social support, climate and capital, policies), and environmental (e.g. weather, workplace, home, neighbourhood, recreation environment, active transportation) determinants of MVPA in a working-age (mean age 18-65 years) female population will be included. Risk of bias will be assessed within and across all included studies using the Tool to Assess Risk of Bias in Cohort Studies and the Grades of Recommendation, Assessment, Development and Evaluation approach. Harvest plots will be used to synthesize results across all determinants, and meta-analyses will be conducted where possible among studies with sufficient homogeneity. This review will provide a

The auto-orientation in high magnetic fields of oxidized cytochrome b562 as source of constraints for solution structure determination

International Nuclear Information System (INIS)

Arnesano, Fabio; Banci, Lucia; Bertini, Ivano; Wetering, Karin van der; Czisch, Michael; Kaptein, Robert

2000-01-01

15 N- 1 H 1 J couplings were measured at 500 MHz and 800 MHz for 15 N enriched oxidized cytochrome b 562 from E. coli. The magnetic field dependence of 70 1 J values, which could be measured without signal overlap, shows that there is a molecular magnetic anisotropy which provides partial molecular orientation in the magnetic field and, consequently, residual dipolar couplings (rdc). The rdc were used as further constraints to improve the existing structure [Arnesano et al. (1999) Biochemistry, 38, 8657-8670] with a protocol which uses the rhombic anisotropy [Banci et al. (1998) J. Am. Chem. Soc., 120, 12903-12909]. The overall large molecular magnetic anisotropy has been found to be determined by both the low spin iron (III) and the four helix bundle structure magnetic susceptibility anisotropy contributions

Fatigue Crack Propagation Simulation in Plane Stress Constraint

DEFF Research Database (Denmark)

Ricardo, Luiz Carlos Hernandes; Spinelli, Dirceu

2010-01-01

Nowadays, structural and materials engineers develop structures and materials properties using finite element method. This work presents a numerical determination of fatigue crack opening and closure stress intensity factors of a C(T) specimen. Two different standard variable spectrum loadings...... are utilized, Mini-Falstaff and Wisper. The effects in two-dimensional (2D) small scale yielding models of fatigue crack growth were studied considering plane stress constraint....

The trade-off between bioenergy and emissions with land constraints

International Nuclear Information System (INIS)

Kauffman, Nathan S.; Hayes, Dermot J.

2013-01-01

Agricultural biofuels require the use of scarce land, and this land has opportunity cost. We explore the objective function of a social planner who includes a land constraint in the optimization decision to minimize environmental cost. The inclusion of this land constraint in our optimization model motivates the measurement of emissions on a per-hectare basis. Switchgrass and corn are modeled as competing alternatives to show how the inclusion of a land constraint can influence life cycle rankings and alter policy conclusions. With land use unconstrained, ethanol produced from switchgrass is always an optimal feedstock relative to ethanol produced from corn. With land use constrained, however, our results show that it is unlikely that switchgrass would be optimal in the midwestern United States, but may be optimal in southern states if carbon is priced relatively high. Whether biofuel policy advocates for one feedstock over another should consider these contrasting results. - Highlights: ► Biofuel pathway rankings differ depending on the functional unit of measure. ► Conventional life cycle analysis overlooks the opportunity cost of land. ► Including a land constraint, a model is developed to determine pathway optimality. ► The optimization model suggests emissions be measured per hectare. ► Switchgrass and corn are modeled as competing alternatives for biofuel production

Trade-off between multiple constraints enables simultaneous formation of modules and hubs in neural systems.

Directory of Open Access Journals (Sweden)

Yuhan Chen

Full Text Available The formation of the complex network architecture of neural systems is subject to multiple structural and functional constraints. Two obvious but apparently contradictory constraints are low wiring cost and high processing efficiency, characterized by short overall wiring length and a small average number of processing steps, respectively. Growing evidence shows that neural networks are results from a trade-off between physical cost and functional value of the topology. However, the relationship between these competing constraints and complex topology is not well understood quantitatively. We explored this relationship systematically by reconstructing two known neural networks, Macaque cortical connectivity and C. elegans neuronal connections, from combinatory optimization of wiring cost and processing efficiency constraints, using a control parameter α, and comparing the reconstructed networks to the real networks. We found that in both neural systems, the reconstructed networks derived from the two constraints can reveal some important relations between the spatial layout of nodes and the topological connectivity, and match several properties of the real networks. The reconstructed and real networks had a similar modular organization in a broad range of α, resulting from spatial clustering of network nodes. Hubs emerged due to the competition of the two constraints, and their positions were close to, and partly coincided, with the real hubs in a range of α values. The degree of nodes was correlated with the density of nodes in their spatial neighborhood in both reconstructed and real networks. Generally, the rebuilt network matched a significant portion of real links, especially short-distant ones. These findings provide clear evidence to support the hypothesis of trade-off between multiple constraints on brain networks. The two constraints of wiring cost and processing efficiency, however, cannot explain all salient features in the real

The constraints

International Nuclear Information System (INIS)

Jones, P.M.S.

1987-01-01

There are considerable incentives for the use of nuclear in preference to other sources for base load electricity generation in most of the developed world. These are economic, strategic, environmental and climatic. However, there are two potential constraints which could hinder the development of nuclear power to its full economic potential. These are public opinion and financial regulations which distort the nuclear economic advantage. The concerns of the anti-nuclear lobby are over safety, (especially following the Chernobyl accident), the management of radioactive waste, the potential effects of large scale exposure of the population to radiation and weapons proliferation. These are discussed. The financial constraint is over two factors, the availability of funds and the perception of cost, both of which are discussed. (U.K.)

Lithium-Ion Battery Online Rapid State-of-Power Estimation under Multiple Constraints

Directory of Open Access Journals (Sweden)

Shun Xiang

2018-01-01

Full Text Available The paper aims to realize a rapid online estimation of the state-of-power (SOP with multiple constraints of a lithium-ion battery. Firstly, based on the improved first-order resistance-capacitance (RC model with one-state hysteresis, a linear state-space battery model is built; then, using the dual extended Kalman filtering (DEKF method, the battery parameters and states, including open-circuit voltage (OCV, are estimated. Secondly, by employing the estimated OCV as the observed value to build the second dual Kalman filters, the battery SOC is estimated. Thirdly, a novel rapid-calculating peak power/SOP method with multiple constraints is proposed in which, according to the bisection judgment method, the battery’s peak state is determined; then, one or two instantaneous peak powers are used to determine the peak power during T seconds. In addition, in the battery operating process, the actual constraint that the battery is under is analyzed specifically. Finally, three simplified versions of the Federal Urban Driving Schedule (SFUDS with inserted pulse experiments are conducted to verify the effectiveness and accuracy of the proposed online SOP estimation method.

Particle physics and the standard cosmology

International Nuclear Information System (INIS)

Sarkar, S.

1985-12-01

The author reviews the constraints imposed by the standard cosmological model on physics beyond the standard SU(3)sub(C) x SU(2)sub(L) x U(1)sub(Y) model, with particular attention to supersymmetry and supergravity. (author)

Sum rules and constraints on passive systems

International Nuclear Information System (INIS)

Bernland, A; Gustafsson, M; Luger, A

2011-01-01

A passive system is one that cannot produce energy, a property that naturally poses constraints on the system. A system in convolution form is fully described by its transfer function, and the class of Herglotz functions, holomorphic functions mapping the open upper half-plane to the closed upper half-plane, is closely related to the transfer functions of passive systems. Following a well-known representation theorem, Herglotz functions can be represented by means of positive measures on the real line. This fact is exploited in this paper in order to rigorously prove a set of integral identities for Herglotz functions that relate weighted integrals of the function to its asymptotic expansions at the origin and infinity. The integral identities are the core of a general approach introduced here to derive sum rules and physical limitations on various passive physical systems. Although similar approaches have previously been applied to a wide range of specific applications, this paper is the first to deliver a general procedure together with the necessary proofs. This procedure is described thoroughly and exemplified with examples from electromagnetic theory.

Tracking using motion estimation with physically motivated inter-region constraints

KAUST Repository

Arif, Omar; Sundaramoorthi, Ganesh; Hong, Byungwoo; Yezzi, Anthony J.

2014-01-01

We propose a method for tracking structures (e.g., ventricles and myocardium) in cardiac images (e.g., magnetic resonance) by propagating forward in time a previous estimate of the structures using a new physically motivated motion estimation scheme

Guided exploration of physically valid shapes for furniture design

KAUST Repository

Umetani, Nobuyuki

2012-07-01

Geometric modeling and the physical validity of shapes are traditionally considered independently. This makes creating aesthetically pleasing yet physically valid models challenging. We propose an interactive design framework for efficient and intuitive exploration of geometrically and physically valid shapes. During any geometric editing operation, the proposed system continuously visualizes the valid range of the parameter being edited. When one or more constraints are violated after an operation, the system generates multiple suggestions involving both discrete and continuous changes to restore validity. Each suggestion also comes with an editing mode that simultaneously adjusts multiple parameters in a coordinated way to maintain validity. Thus, while the user focuses on the aesthetic aspects of the design, our computational design framework helps to achieve physical realizability by providing active guidance to the user. We demonstrate our framework on plankbased furniture design with nail-joint and frictional constraints. We use our system to design a range of examples, conduct a user study, and also fabricate a physical prototype to test the validity and usefulness of the system. © 2012 ACM 0730-0301/2012/08- ART86.

Why did the savant syndrome not spread in the population? A psychiatric example of a developmental constraint.

Science.gov (United States)

Ploeger, Annemie; van der Maas, Han L J; Raijmakers, Maartje E J; Galis, Frietson

2009-03-31

A developmental constraint is a mechanism that limits the possibility of a phenotype to evolve. There is growing evidence for the existence of developmental constraints in the biological literature. We hypothesize that a developmental constraint prevents the savant syndrome, despite its positive aspects, from spreading in the population. Here, the developmental constraint is the result of the high interactivity among body parts in an early stage in embryological development, namely early organogenesis or the phylotypic stage. The interactivity during this stage involves all components of the embryo, and as a result mutations that affect one part of the embryo also affect other parts. We hypothesize that a mutation, which gives rise to the development of the positive aspects of the savant syndrome (e.g., an impressive memory capacity), will virtually always have a deleterious effect on the development of other phenotypic traits (e.g., resulting in autism and/or impaired motor coordination). Thus, our hypothesis states that the savant syndrome cannot spread in the population because of this developmental constraint. The finding that children with savant syndrome often have autism and physical anomalies, which are known to be established during early organogenesis, supports our hypothesis.

Firehose constraints of the bi-Kappa-distributed electrons: a zero-order approach for the suprathermal electrons in the solar wind

Czech Academy of Sciences Publication Activity Database

Lazar, M.; Shaaban, S. M.; Poedts, S.; Štverák, Štěpán

2017-01-01

Roč. 464, č. 1 (2017), s. 564-571 ISSN 0035-8711 Institutional support: RVO:68378289 Keywords : instabilities * plasmas * methods * analytical * methods: observational * solar wind Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 4.961, year: 2016 https://academic.oup.com/mnras/article-abstract/464/1/564/2236068/Firehose-constraints-of-the-bi-Kappa-distributed?redirectedFrom=fulltext

Development of safety analysis and constraint detection techniques for process interaction errors

Energy Technology Data Exchange (ETDEWEB)

Fan, Chin-Feng, E-mail: csfanc@saturn.yzu.edu.tw [Computer Science and Engineering Dept., Yuan-Ze University, Taiwan (China); Tsai, Shang-Lin; Tseng, Wan-Hui [Computer Science and Engineering Dept., Yuan-Ze University, Taiwan (China)

2011-02-15

Among the new failure modes introduced by computer into safety systems, the process interaction error is the most unpredictable and complicated failure mode, which may cause disastrous consequences. This paper presents safety analysis and constraint detection techniques for process interaction errors among hardware, software, and human processes. Among interaction errors, the most dreadful ones are those that involve run-time misinterpretation from a logic process. We call them the 'semantic interaction errors'. Such abnormal interaction is not adequately emphasized in current research. In our static analysis, we provide a fault tree template focusing on semantic interaction errors by checking conflicting pre-conditions and post-conditions among interacting processes. Thus, far-fetched, but highly risky, interaction scenarios involve interpretation errors can be identified. For run-time monitoring, a range of constraint types is proposed for checking abnormal signs at run time. We extend current constraints to a broader relational level and a global level, considering process/device dependencies and physical conservation rules in order to detect process interaction errors. The proposed techniques can reduce abnormal interactions; they can also be used to assist in safety-case construction.

Development of safety analysis and constraint detection techniques for process interaction errors

International Nuclear Information System (INIS)

Fan, Chin-Feng; Tsai, Shang-Lin; Tseng, Wan-Hui

2011-01-01

Among the new failure modes introduced by computer into safety systems, the process interaction error is the most unpredictable and complicated failure mode, which may cause disastrous consequences. This paper presents safety analysis and constraint detection techniques for process interaction errors among hardware, software, and human processes. Among interaction errors, the most dreadful ones are those that involve run-time misinterpretation from a logic process. We call them the 'semantic interaction errors'. Such abnormal interaction is not adequately emphasized in current research. In our static analysis, we provide a fault tree template focusing on semantic interaction errors by checking conflicting pre-conditions and post-conditions among interacting processes. Thus, far-fetched, but highly risky, interaction scenarios involve interpretation errors can be identified. For run-time monitoring, a range of constraint types is proposed for checking abnormal signs at run time. We extend current constraints to a broader relational level and a global level, considering process/device dependencies and physical conservation rules in order to detect process interaction errors. The proposed techniques can reduce abnormal interactions; they can also be used to assist in safety-case construction.

Reducing constraints on quantum computer design by encoded selective recoupling

International Nuclear Information System (INIS)

Lidar, D.A.; Wu, L.-A.

2002-01-01

The requirement of performing both single-qubit and two-qubit operations in the implementation of universal quantum logic often leads to very demanding constraints on quantum computer design. We show here how to eliminate the need for single-qubit operations in a large subset of quantum computer proposals: those governed by isotropic and XXZ , XY -type anisotropic exchange interactions. Our method employs an encoding of one logical qubit into two physical qubits, while logic operations are performed using an analogue of the NMR selective recoupling method

Optimal Attack Strategies Subject to Detection Constraints Against Cyber-Physical Systems

International Nuclear Information System (INIS)

Chen, Yuan; Kar, Soummya; Moura, Jose M. F.

2017-01-01

This paper studies an attacker against a cyberphysical system (CPS) whose goal is to move the state of a CPS to a target state while ensuring that his or her probability of being detected does not exceed a given bound. The attacker’s probability of being detected is related to the nonnegative bias induced by his or her attack on the CPS’s detection statistic. We formulate a linear quadratic cost function that captures the attacker’s control goal and establish constraints on the induced bias that reflect the attacker’s detection-avoidance objectives. When the attacker is constrained to be detected at the false-alarm rate of the detector, we show that the optimal attack strategy reduces to a linear feedback of the attacker’s state estimate. In the case that the attacker’s bias is upper bounded by a positive constant, we provide two algorithms – an optimal algorithm and a sub-optimal, less computationally intensive algorithm – to find suitable attack sequences. Lastly, we illustrate our attack strategies in numerical examples based on a remotely-controlled helicopter under attack.

Developmental constraints on behavioural flexibility.

Science.gov (United States)

Holekamp, Kay E; Swanson, Eli M; Van Meter, Page E

2013-05-19

We suggest that variation in mammalian behavioural flexibility not accounted for by current socioecological models may be explained in part by developmental constraints. From our own work, we provide examples of constraints affecting variation in behavioural flexibility, not only among individuals, but also among species and higher taxonomic units. We first implicate organizational maternal effects of androgens in shaping individual differences in aggressive behaviour emitted by female spotted hyaenas throughout the lifespan. We then compare carnivores and primates with respect to their locomotor and craniofacial adaptations. We inquire whether antagonistic selection pressures on the skull might impose differential functional constraints on evolvability of skulls and brains in these two orders, thus ultimately affecting behavioural flexibility in each group. We suggest that, even when carnivores and primates would theoretically benefit from the same adaptations with respect to behavioural flexibility, carnivores may nevertheless exhibit less behavioural flexibility than primates because of constraints imposed by past adaptations in the morphology of the limbs and skull. Phylogenetic analysis consistent with this idea suggests greater evolutionary lability in relative brain size within families of primates than carnivores. Thus, consideration of developmental constraints may help elucidate variation in mammalian behavioural flexibility.

Learning With Mixed Hard/Soft Pointwise Constraints.

Science.gov (United States)

Gnecco, Giorgio; Gori, Marco; Melacci, Stefano; Sanguineti, Marcello

2015-09-01

A learning paradigm is proposed and investigated, in which the classical framework of learning from examples is enhanced by the introduction of hard pointwise constraints, i.e., constraints imposed on a finite set of examples that cannot be violated. Such constraints arise, e.g., when requiring coherent decisions of classifiers acting on different views of the same pattern. The classical examples of supervised learning, which can be violated at the cost of some penalization (quantified by the choice of a suitable loss function) play the role of soft pointwise constraints. Constrained variational calculus is exploited to derive a representer theorem that provides a description of the functional structure of the optimal solution to the proposed learning paradigm. It is shown that such an optimal solution can be represented in terms of a set of support constraints, which generalize the concept of support vectors and open the doors to a novel learning paradigm, called support constraint machines. The general theory is applied to derive the representation of the optimal solution to the problem of learning from hard linear pointwise constraints combined with soft pointwise constraints induced by supervised examples. In some cases, closed-form optimal solutions are obtained.

Imposing motion constraints to a force reflecting tele-robot through real-time simulation of a virtual mechanism

Energy Technology Data Exchange (ETDEWEB)

Joly, L.; Andriot, C.

1995-12-31

In a tele-operation system, assistance can be given to the operator by constraining the tele-robot position to remain within a restricted subspace of its workspace. A new approach to motion constraint is presented in this paper. The control law is established simulating a virtual ideal mechanism acting as a jig, and connected to the master and slave arms via springs and dampers. Using this approach, it is possible to impose any (sufficiently smooth) motion constraint to the system, including non linear constraints (complex surfaces) involving coupling between translations and rotations and physical equivalence ensures that the controller is passive. Experimental results obtained with a 6-DOF tele-operation system are given. Other applications of the virtual mechanism concept include hybrid position-force control and haptic interfaces. (authors). 11 refs., 7 figs.

Imposing motion constraints to a force reflecting tele-robot through real-time simulation of a virtual mechanism

International Nuclear Information System (INIS)

Joly, L.; Andriot, C.

1995-01-01

In a tele-operation system, assistance can be given to the operator by constraining the tele-robot position to remain within a restricted subspace of its workspace. A new approach to motion constraint is presented in this paper. The control law is established simulating a virtual ideal mechanism acting as a jig, and connected to the master and slave arms via springs and dampers. Using this approach, it is possible to impose any (sufficiently smooth) motion constraint to the system, including non linear constraints (complex surfaces) involving coupling between translations and rotations and physical equivalence ensures that the controller is passive. Experimental results obtained with a 6-DOF tele-operation system are given. Other applications of the virtual mechanism concept include hybrid position-force control and haptic interfaces. (authors). 11 refs., 7 figs

Physics from symmetry

CERN Document Server

Schwichtenberg, Jakob

2018-01-01

This is a textbook that derives the fundamental theories of physics from symmetry. It starts by introducing, in a completely self-contained way, all mathematical tools needed to use symmetry ideas in physics. Thereafter, these tools are put into action and by using symmetry constraints, the fundamental equations of Quantum Mechanics, Quantum Field Theory, Electromagnetism, and Classical Mechanics are derived. As a result, the reader is able to understand the basic assumptions behind, and the connections between the modern theories of physics. The book concludes with first applications of the previously derived equations. Thanks to the input of readers from around the world, this second edition has been purged of typographical errors and also contains several revised sections with improved explanations. .

Not enough time? Individual and environmental implications for workplace physical activity programming among women with and without young children.

Science.gov (United States)

Tavares, Leonor S; Plotnikoff, Ronald C

2008-03-01

This study sets out to determine the main issues employed women with and without young children voice as influencing their physical activity behaviors, and to identify the environmental dimensions (e.g., physical, social, cultural, organizational, policy) within and outside of the workplace surrounding physical activity promotion that are most pertinent to employed women in Canada. Thirty employed women participated in focus groups, and four senior personnel were interviewed. Worksite observations were carried out and a Workplace Physical Activity Audit Tool was administered. Results indicate that time constraints and demands of personal and work life are barriers to achieving more activity. The issues surrounding family obligations and pressures for women with young children illustrate the main differences between groups. Key environmental factors are addressed and considered for future workplace physical activity programming goals.

Short-sale Constraints and Credit Runs

DEFF Research Database (Denmark)

Venter, Gyuri

), creditors with high private signals are more lenient to roll over debt, and a bank with lower asset quality remains solvent. This leads to higher allocative efficiency in the real economy. My result thus implies that the decrease in average informativeness due to short-sale constraints can be more than......This paper studies how short-sale constraints affect the informational efficiency of market prices and the link between prices and economic activity. I show that under short-sale constraints security prices contain less information. However, short-sale constraints increase the informativeness...... the price of an asset the bank holds. I show that short-selling constraints in the financial market lead to the revival of self-fulfilling beliefs about the beliefs and actions of others, and create multiple equilibria. In the equilibrium where agents rely more on public information (i.e., the price...

[Experimental and theoretical high energy physics program

Energy Technology Data Exchange (ETDEWEB)

Finley, J.; Gaidos, J.A.; Loeffler, F.J.; McIlwain, R.L.; Miller, D.H.; Palfrey, T.R.; Shibata, E.I.; Shipsey, I.P.

1993-04-01

Experimental and theoretical high-energy physics research at Purdue is summarized in a number of reports. Subjects treated include the following: the CLEO experiment for the study of heavy flavor physics; gas microstrip detectors; particle astrophysics; affine Kac{endash}Moody algebra; nonperturbative mass bounds on scalar and fermion systems due to triviality and vacuum stability constraints; resonance neutrino oscillations; e{sup +}e{sup {minus}} collisions at CERN; {bar p}{endash}p collisions at FNAL; accelerator physics at Fermilab; development work for the SDC detector at SSC; TOPAZ; D-zero physics; physics beyond the standard model; and the Collider Detector at Fermilab. (RWR)

[Experimental and theoretical high energy physics program

International Nuclear Information System (INIS)

Finley, J.; Gaidos, J.A.; Loeffler, F.J.; McIlwain, R.L.; Miller, D.H.; Palfrey, T.R.; Shibata, E.I.; Shipsey, I.P.

1993-04-01

Experimental and theoretical high-energy physics research at Purdue is summarized in a number of reports. Subjects treated include the following: the CLEO experiment for the study of heavy flavor physics; gas microstrip detectors; particle astrophysics; affine Kac endash Moody algebra; nonperturbative mass bounds on scalar and fermion systems due to triviality and vacuum stability constraints; resonance neutrino oscillations; e + e - collisions at CERN; bar p endash p collisions at FNAL; accelerator physics at Fermilab; development work for the SDC detector at SSC; TOPAZ; D-zero physics; physics beyond the standard model; and the Collider Detector at Fermilab

A Foot-Mounted Inertial Measurement Unit (IMU) Positioning Algorithm Based on Magnetic Constraint.

Science.gov (United States)

Wang, Yan; Li, Xin; Zou, Jiaheng

2018-03-01

With the development of related applications, indoor positioning techniques have been more and more widely developed. Based on Wi-Fi, Bluetooth low energy (BLE) and geomagnetism, indoor positioning techniques often rely on the physical location of fingerprint information. The focus and difficulty of establishing the fingerprint database are in obtaining a relatively accurate physical location with as little given information as possible. This paper presents a foot-mounted inertial measurement unit (IMU) positioning algorithm under the loop closure constraint based on magnetic information. It can provide relatively reliable position information without maps and geomagnetic information and provides a relatively accurate coordinate for the collection of a fingerprint database. In the experiment, the features extracted by the multi-level Fourier transform method proposed in this paper are validated and the validity of loop closure matching is tested with a RANSAC-based method. Moreover, the loop closure detection results show that the cumulative error of the trajectory processed by the graph optimization algorithm is significantly suppressed, presenting a good accuracy. The average error of the trajectory under loop closure constraint is controlled below 2.15 m.

A Foot-Mounted Inertial Measurement Unit (IMU Positioning Algorithm Based on Magnetic Constraint

Directory of Open Access Journals (Sweden)

Yan Wang

2018-03-01

Full Text Available With the development of related applications, indoor positioning techniques have been more and more widely developed. Based on Wi-Fi, Bluetooth low energy (BLE and geomagnetism, indoor positioning techniques often rely on the physical location of fingerprint information. The focus and difficulty of establishing the fingerprint database are in obtaining a relatively accurate physical location with as little given information as possible. This paper presents a foot-mounted inertial measurement unit (IMU positioning algorithm under the loop closure constraint based on magnetic information. It can provide relatively reliable position information without maps and geomagnetic information and provides a relatively accurate coordinate for the collection of a fingerprint database. In the experiment, the features extracted by the multi-level Fourier transform method proposed in this paper are validated and the validity of loop closure matching is tested with a RANSAC-based method. Moreover, the loop closure detection results show that the cumulative error of the trajectory processed by the graph optimization algorithm is significantly suppressed, presenting a good accuracy. The average error of the trajectory under loop closure constraint is controlled below 2.15 m.

The SuperB Project: Status and the Physics Reach

International Nuclear Information System (INIS)

Neri, Nicola

2012-01-01

The SuperB experiment is a next generation Super Flavour Factory expected to accumulate 75 ab −1 of data at the Υ(4S) in five years of nominal running, and will be built at the recently established Cabibbo Laboratory on the outskirts of Rome. In addition to running data at the Υ(4S), SuperB will be able to accumulate data from the ψ(3770) up to the Υ(6S). A polarized electron beam enables unique physics opportunities at SuperB. The large samples of B, D and τ decays that will be recorded at SuperB can be used to provide both stringent constraints on new physics scenarios, and over-constraints on the Standard Model. We present the status of the project as well as the physics potential of SuperB.

Constraint-based Word Segmentation for Chinese

DEFF Research Database (Denmark)

Christiansen, Henning; Bo, Li

2014-01-01

-hoc and statistically based methods. In this paper, we show experiments of implementing different approaches to CWSP in the framework of CHR Grammars [Christiansen, 2005] that provides a constraint solving approach to language analysis. CHR Grammars are based upon Constraint Handling Rules, CHR [Frühwirth, 1998, 2009......], which is a declarative, high-level programming language for specification and implementation of constraint solvers....

Updated constraints on velocity and momentum-dependent asymmetric dark matter

Energy Technology Data Exchange (ETDEWEB)

Vincent, Aaron C. [Institute for Particle Physics Phenomenology (IPPP),Department of Physics, Durham University,Durham DH1 3LE (United Kingdom); Blackett Laboratory, Department of Physics, Imperial College London,Prince Consort Road, London SW7 2AZ (United Kingdom); Scott, Pat [Blackett Laboratory, Department of Physics, Imperial College London,Prince Consort Road, London SW7 2AZ (United Kingdom); Serenelli, Aldo [Institut de Ciències de l’Espai (ICE-CSIC/IEEC),Campus UAB, Carrer de Can Magrans s/n, 08193 Cerdanyola del Vallés (Spain)

2016-11-04

We present updated constraints on dark matter models with momentum-dependent or velocity-dependent interactions with nuclei, based on direct detection and solar physics. We improve our previous treatment of energy transport in the solar interior by dark matter scattering, leading to significant changes in fits to many observables. Based on solar physics alone, DM with a spin-independent q{sup 4} coupling provides the best fit to data, and a statistically satisfactory solution to the solar abundance problem. Once direct detection limits are accounted for however, the best solution is spin-dependent v{sup 2} scattering with a reference cross-section of 10{sup −35} cm{sup 2} (at a reference velocity of v{sub 0}=220 km s{sup −1}), and a dark matter mass of about 5 GeV.

Gravity in two-time physics

International Nuclear Information System (INIS)

Bars, Itzhak

2008-01-01

The field theoretic action for gravitational interactions in d+2 dimensions is constructed in the formalism of two-time (2T) physics. General relativity in d dimensions emerges as a shadow of this theory with one less time and one less space dimensions. The gravitational constant turns out to be a shadow of a dilaton field in d+2 dimensions that appears as a constant to observers stuck in d dimensions. If elementary scalar fields play a role in the fundamental theory (such as Higgs fields in the standard model coupled to gravity), then their shadows in d dimensions must necessarily be conformal scalars. This has the physical consequence that the gravitational constant changes at each phase transition (inflation, grand unification, electroweak, etc.), implying interesting new scenarios in cosmological applications. The fundamental action for pure gravity, which includes the spacetime metric G MN (X), the dilaton Ω(X), and an additional auxiliary scalar field W(X), all in d+2 dimensions with two times, has a mix of gauge symmetries to produce appropriate constraints that remove all ghosts or redundant degrees of freedom. The action produces on-shell classical field equations of motion in d+2 dimensions, with enough constraints for the theory to be in agreement with classical general relativity in d dimensions. Therefore this action describes the correct classical gravitational physics directly in d+2 dimensions. Taken together with previous similar work on the standard model of particles and forces, the present paper shows that 2T physics is a general consistent framework for a physical theory. Furthermore, the 2T-physics approach reveals more physical information for observers stuck in the shadow in d dimensions in the form of hidden symmetries and dualities, that are largely concealed in the usual one-time formulation of physics

Distributed constraint satisfaction for coordinating and integrating a large-scale, heterogenous enterprise

CERN Document Server

Eisenberg, C

2003-01-01

Market forces are continuously driving public and private organisations towards higher productivity, shorter process and production times, and fewer labour hours. To cope with these changes, organisations are adopting new organisational models of coordination and cooperation that increase their flexibility, consistency, efficiency, productivity and profit margins. In this thesis an organisational model of coordination and cooperation is examined using a real life example; the technical integration of a distributed large-scale project of an international physics collaboration. The distributed resource constraint project scheduling problem is modelled and solved with the methods of distributed constraint satisfaction. A distributed local search method, the distributed breakout algorithm (DisBO), is used as the basis for the coordination scheme. The efficiency of the local search method is improved by extending it with an incremental problem solving scheme with variable ordering. The scheme is implemented as cen...

Evading the pulsar constraints on the cosmic string tension in supergravity inflation

Energy Technology Data Exchange (ETDEWEB)

Kamada, Kohei [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Miyamoto, Yuhei [Tokyo Univ. (Japan). Dept. of Physics; Tokyo Univ. (JP). Research Center for the Early Universe (RESCEU); Yokoyama, Jun' ichi [Tokyo Univ. (JP). Research Center for the Early Universe (RESCEU); Tokyo Univ., Kashiwa, Chiba (JP). Inst. for the Physics and Mathematics of the Universe (IPMU)

2012-04-15

The cosmic string is a useful probe of the early Universe and may give us a clue to physics at high energy scales where any artificial particle accelerators cannot reach. Although one of the most promising tools is the cosmic microwave background, the constraint from gravitational waves is becoming so stringent that one may not hope to detect its signatures in the cosmic microwave background. In this paper, we construct a scenario that contains cosmic strings observable in the cosmic microwave background while evading the constraint imposed by the recent pulsar timing data. We argue that cosmic strings with relatively large tension are allowed by delaying the onset of the scaling regime. We also show that this scenario is naturally realized in the context of chaotic inflation in supergravity, where the phase transition is governed by the Hubble induced mass.

Optimization of regional water - power systems under cooling constraints and climate change

DEFF Research Database (Denmark)

Payet-burin, Raphaël; Bertoni, Federica; Davidsen, Claus

2018-01-01

Thermo-electric generation represents 70% of Europe's electricity production and 43% of water withdrawals, and is therefore a key element of the water-energy nexus. In 2003, 2006 and 2009, several thermal power plants had to be switched off in Europe because of heat waves, showing the need...... to assess the impact of climate change on cooling constraints of thermal power plants. An integrated water-power model of the Iberian Peninsula was developed in this study. It includes a physical hydrologic representation, spatially and temporally resolved water demands, management of water infrastructure...... and a simple power system model. The system was evaluated under present and future climatic conditions using different climate change scenarios. The cost of cooling constraints is found to increase by 220–640 million €/year, for the period 2046–2065 depending on the climate change scenario. Average available...

Evading the pulsar constraints on the cosmic string tension in supergravity inflation

International Nuclear Information System (INIS)

Kamada, Kohei; Miyamoto, Yuhei; Yokoyama, Jun'ichi

2012-04-01

The cosmic string is a useful probe of the early Universe and may give us a clue to physics at high energy scales where any artificial particle accelerators cannot reach. Although one of the most promising tools is the cosmic microwave background, the constraint from gravitational waves is becoming so stringent that one may not hope to detect its signatures in the cosmic microwave background. In this paper, we construct a scenario that contains cosmic strings observable in the cosmic microwave background while evading the constraint imposed by the recent pulsar timing data. We argue that cosmic strings with relatively large tension are allowed by delaying the onset of the scaling regime. We also show that this scenario is naturally realized in the context of chaotic inflation in supergravity, where the phase transition is governed by the Hubble induced mass.

Design variables and constraints in fashion store design processes

DEFF Research Database (Denmark)

Haug, Anders; Borch Münster, Mia

2015-01-01

is to identify the most important store design variables, organise these variables into categories, understand the design constraints between categories, and determine the most influential stakeholders. Design/methodology/approach: – Based on a discussion of existing literature, the paper defines a framework...... into categories, provides an understanding of constraints between categories of variables, and identifies the most influential stakeholders. The paper demonstrates that the fashion store design task can be understood through a system perspective, implying that the store design task becomes a matter of defining......Purpose: – Several frameworks of retail store environment variables exist, but as shown by this paper, they are not particularly well-suited for supporting fashion store design processes. Thus, in order to provide an improved understanding of fashion store design, the purpose of this paper...

University Course Timetabling using Constraint Programming

Directory of Open Access Journals (Sweden)

Hadi Shahmoradi

2017-03-01

Full Text Available University course timetabling problem is a challenging and time-consuming task on the overall structure of timetable in every academic environment. The problem deals with many factors such as the number of lessons, classes, teachers, students and working time, and these are influenced by some hard and soft constraints. The aim of solving this problem is to assign courses and classes to teachers and students, so that the restrictions are held. In this paper, a constraint programming method is proposed to satisfy maximum constraints and expectation, in order to address university timetabling problem. For minimizing the penalty of soft constraints, a cost function is introduced and AHP method is used for calculating its coefficients. The proposed model is tested on department of management, University of Isfahan dataset using OPL on the IBM ILOG CPLEX Optimization Studio platform. A statistical analysis has been conducted and shows the performance of the proposed approach in satisfying all hard constraints and also the satisfying degree of the soft constraints is on maximum desirable level. The running time of the model is less than 20 minutes that is significantly better than the non-automated ones.

Psychological constraints on egalitarianism

DEFF Research Database (Denmark)

Kasperbauer, Tyler Joshua

2015-01-01

processes motivating people to resist various aspects of egalitarianism. I argue for two theses, one normative and one descriptive. The normative thesis holds that egalitarians must take psychological constraints into account when constructing egalitarian ideals. I draw from non-ideal theories in political...... philosophy, which aim to construct moral goals with current social and political constraints in mind, to argue that human psychology must be part of a non-ideal theory of egalitarianism. The descriptive thesis holds that the most fundamental psychological challenge to egalitarian ideals comes from what......Debates over egalitarianism for the most part are not concerned with constraints on achieving an egalitarian society, beyond discussions of the deficiencies of egalitarian theory itself. This paper looks beyond objections to egalitarianism as such and investigates the relevant psychological...

Constraint Programming for Context Comprehension

DEFF Research Database (Denmark)

Christiansen, Henning

2014-01-01

A close similarity is demonstrated between context comprehension, such as discourse analysis, and constraint programming. The constraint store takes the role of a growing knowledge base learned throughout the discourse, and a suitable con- straint solver does the job of incorporating new pieces...

Objectively measured physical environmental neighbourhood factors are not associated with accelerometer-determined total sedentary time in adults

OpenAIRE

Compernolle, Sofie; De Cocker, Katrien; Mackenbach, Joreintje D.; Van Nassau, Femke; Lakerveld, Jeroen; Cardon, Greet; De Bourdeaudhuij, Ilse

2017-01-01

Background: The physical neighbourhood environment may influence adults' sedentary behaviour. Yet, most studies examining the association between the physical neighbourhood environment and sedentary behaviour rely on self-reported data of either the physical neighbourhood environment and/or sedentary behaviour. The aim of this study was to investigate the associations between objectively measured physical environmental neighbourhood factors and accelerometer-determined total sedentary time in...

SU-F-T-128: Dose-Volume Constraints for Particle Therapy Treatment Planning

Energy Technology Data Exchange (ETDEWEB)

Stewart, R; Smith, W; Hendrickson, K; Meyer, J; Cao, N; Lee, E; Gopan, O; Sandison, G; Parvathaneni, U; Laramore, G [University of Washington, Seattle, WA (United States)

2016-06-15

Purpose: Determine equivalent Organ at Risk (OAR) tolerance dose (TD) constraints for MV x-rays and particle therapy. Methods: Equivalent TD estimates for MV x-rays are determined from an isoeffect, regression-analysis of published and in-house constraints for various fractionation schedules (n fractions). The analysis yields an estimate of (α/β) for an OAR. To determine equivalent particle therapy constraints, the MV x-ray TD(n) values are divided by the RBE for DSB induction (RBE{sub DSB}) or cell survival (RBE{sub S}). Estimates of (RBE{sub DSB}) are computed using the Monte Carlo Damage Simulation, and estimates of RBES are computed using the Repair-Misrepair-Fixation (RMF) model. A research build of the RayStation™ treatment planning system implementing the above model is used to estimate (RBE{sub DSB}) for OARs of interest in 16 proton therapy patient plans (head and neck, thorax, prostate and brain). Results: The analysis gives an (α/β) estimate of about 20 Gy for the trachea and heart and 2–4 Gy for the esophagus, spine, and brachial plexus. Extrapolation of MV x-ray constraints (n = 1) to fast neutrons using RBE{sub DSB} = 2.7 are in excellent agreement with clinical experience (n = 10 to 20). When conventional (n > 30) x-ray treatments are used as the reference radiation, fast neutron RBE increased to a maximum of 6. For comparison to a constant RBE of 1.1, the RayStation™ analysis gave estimates of proton RBE{sub DSB} from 1.03 to 1.33 for OARs of interest. Conclusion: The presented system of models is a convenient formalism to synthesize from multiple sources of information a set of self-consistent plan constraints for MV x-ray and hadron therapy treatments. Estimates of RBE{sub DSB} from the RayStation™ analysis differ substantially from 1.1 and vary among patients and treatment sites. A treatment planning system that incorporates patient and anatomy-specific corrections in proton RBE would create opportunities to increase the therapeutic

Revisiting big-bang nucleosynthesis constraints on dark-matter annihilation

Energy Technology Data Exchange (ETDEWEB)

Kawasaki, Masahiro [Institute for Cosmic Ray Research, The University of Tokyo, Kashiwa 277-8582 (Japan); Kavli IPMU (WPI), UTIAS, The University of Tokyo, Kashiwa 277-8583 (Japan); Kohri, Kazunori [Theory Center, IPNS, KEK, Tsukuba 305-0801 (Japan); Sokendai, Tsukuba 305-0801 (Japan); Moroi, Takeo [Kavli IPMU (WPI), UTIAS, The University of Tokyo, Kashiwa 277-8583 (Japan); Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan); Takaesu, Yoshitaro, E-mail: takaesu@hep-th.phys.s.u-tokyo.ac.jp [Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan)

2015-12-17

We study the effects of dark-matter annihilation during the epoch of big-bang nucleosynthesis on the primordial abundances of light elements. We improve the calculation of the light-element abundances by taking into account the effects of anti-nucleons emitted by the annihilation of dark matter and the interconversion reactions of neutron and proton at inelastic scatterings of energetic nucleons. Comparing the theoretical prediction of the primordial light-element abundances with the latest observational constraints, we derive upper bounds on the dark-matter pair-annihilation cross section. Implication to some of particle-physics models are also discussed.

Revisiting big-bang nucleosynthesis constraints on dark-matter annihilation

Directory of Open Access Journals (Sweden)

Masahiro Kawasaki

2015-12-01

Full Text Available We study the effects of dark-matter annihilation during the epoch of big-bang nucleosynthesis on the primordial abundances of light elements. We improve the calculation of the light-element abundances by taking into account the effects of anti-nucleons emitted by the annihilation of dark matter and the interconversion reactions of neutron and proton at inelastic scatterings of energetic nucleons. Comparing the theoretical prediction of the primordial light-element abundances with the latest observational constraints, we derive upper bounds on the dark-matter pair-annihilation cross section. Implication to some of particle-physics models are also discussed.

Theoretical and Experimental Physics

Energy Technology Data Exchange (ETDEWEB)

Nelson, Ann E. [Univ. of Washington, Seattle, WA (United States); Ellis, Stephen D. [Univ. of Washington, Seattle, WA (United States); Karch, Andreas [Univ. of Washington, Seattle, WA (United States); Rosenberg, Leslie [Univ. of Washington, Seattle, WA (United States); Sharpe, Stephene R. [Univ. of Washington, Seattle, WA (United States); Wilkes, R. Jeffrey [Univ. of Washington, Seattle, WA (United States); Yaffe, Laurence G. [Univ. of Washington, Seattle, WA (United States)

2015-04-07

We report on progress towards finding axion dark matter, neutrino oscillation parameters, Use of the gravity/gauge correspondence to to calculations in strongly coupled systems, use of jet substructure to search for new physics, use of lattice QCD to compute weak matrix elements, constraints on dark matter interactions from neutron stars, exotic Higgs searches, and new dark matter models.

Analysis of GEANT4 Physics List Properties in the 12 GeV MOLLER Simulation Framework

Science.gov (United States)

Haufe, Christopher; Moller Collaboration

2013-10-01

To determine the validity of new physics beyond the scope of the electroweak theory, nuclear physicists across the globe have been collaborating on future endeavors that will provide the precision needed to confirm these speculations. One of these is the MOLLER experiment - a low-energy particle experiment that will utilize the 12 GeV upgrade of Jefferson Lab's CEBAF accelerator. The motivation of this experiment is to measure the parity-violating asymmetry of scattered polarized electrons off unpolarized electrons in a liquid hydrogen target. This measurement would allow for a more precise determination of the electron's weak charge and weak mixing angle. While still in its planning stages, the MOLLER experiment requires a detailed simulation framework in order to determine how the project should be run in the future. The simulation framework for MOLLER, called ``remoll'', is written in GEANT4 code. As a result, the simulation can utilize a number of GEANT4 coded physics lists that provide the simulation with a number of particle interaction constraints based off of different particle physics models. By comparing these lists with one another using the data-analysis application ROOT, the most optimal physics list for the MOLLER simulation can be determined and implemented. This material is based upon work supported by the National Science Foundation under Grant No. 714001.

Some cosmological constraints on gauge theories

International Nuclear Information System (INIS)

Schramm, D.N.

1983-01-01

In these lectures, a review is made of various constraints cosmology may place on gauge theories. Particular emphasis is placed on those constraints obtainable from Big Bang Nucleosynthesis, with only brief mention made of Big Bang Baryosynthesis. There is also a considerable discussion of astrophysical constraints on masses and lifetimes of neutrinos with specific mention of the 'missing mass (light)' problem of galactic dynamics. (orig./HSI)

Exploring the Relationship between Self-Determination Theory, Adults' Barriers to Exercise, and Physical Activity

Science.gov (United States)

Ball, James W.; Bice, Matthew R.; Maljak, Kimberly A.

2017-01-01

Physical activity is a preventative measure that can help decrease obesity trends. However, many individuals struggle to live a physically active lifestyle. The purpose of this study was to explore the relationships between Self-Determination Theory, adults' barriers to exercise, and those who have met and have not met the Center for Disease…

[Physical activity and sedentary lifestyle: family and socio-demographic determinants and their impact on adolescents' health].

Science.gov (United States)

Lavielle-Sotomayor, Pilar; Pineda-Aquino, Victoria; Jáuregui-Jiménez, Omar; Castillo-Trejo, Martha

2014-01-01

Estimating whether adolescents' sedentary behaviour and their lack of physical activity is determined by family characteristics or socio-cultural aspects and their impact on health and adiposity level. 932 adolescents were surveyed. Information regarding physical activity, sedentary behaviour, anthropometric index and family characteristics (structure, dynamics and functioning) was estimated by adolescents answering a questionnaire. The sample's average age was 16.07±1.09 years old, 56.3 % were female, 66.3 % had a low level of physical activity and 51.9 % were sedentary. A lack of physical activity occurred more frequently in females (56.8 % cf 41.5 %: p=0.000); family characteristics did not influence such risk behaviour. A relationship between physical activity and sedentary lifestyle with BMI could not be demonstrated, whilst waist circumference was associated with risky behaviour patterns. Teenagers in good health were more active (36.1 % cf 27 %) and less sedentary (49.3 % cf 59.4 %) than those for whom an unhealthy state was reported. Sedentary behaviour and a lack of physical activity were more determined by socio-demographic factors than family aspects, such behaviour pattern having a direct influence on the adolescents' health.

Constraint Lie algebra and local physical Hamiltonian for a generic 2D dilatonic model

International Nuclear Information System (INIS)

Corichi, Alejandro; Karami, Asieh; Rastgoo, Saeed; Vukašinac, Tatjana

2016-01-01

We consider a class of two-dimensional dilatonic models, and revisit them from the perspective of a new set of ‘polar type’ variables. These are motivated by recently defined variables within the spherically symmetric sector of 4D general relativity. We show that for a large class of dilatonic models, including the case with matter, one can perform a series of canonical transformations in such a way that the Poisson algebra of the constraints becomes a Lie algebra. Furthermore, we construct Dirac observables and a reduced Hamiltonian that accounts for the time evolution of the system. (paper)

Socioeconomic constraints on the technological choices in rural sewage treatment.

Science.gov (United States)

Gu, Baojing; Fan, Liangcong; Ying, Zechun; Xu, Qingshan; Luo, Weidong; Ge, Ying; Scott, Steffanie; Chang, Jie

2016-10-01

Technological innovation is one of the potential engines to mitigate environmental pollution. However, the implementation of new technologies sometimes fails owing to socioeconomic constraints from different stakeholders. Thus, it is essential to analyze constraints of environmental technologies in order to build a pathway for their implementation. In this study, taking three technologies on rural sewage treatment in Hangzhou, China as a case study, i.e., wastewater treatment plant (WTP), constructed wetland (CW), and biogas system, we analyzed how socioeconomic constraints affect the technological choices. Results showed that socioeconomic constraints play a key role through changing the relative opportunity cost of inputs from government as compared to that of residents to deliver the public good-sewage treatment-under different economic levels. Economic level determines the technological choice, and the preferred sewage treatment technologies change from biogas system to CW and further to WTP along with the increase of economic level. Mismatch of technological choice and economic level results in failures of rural sewage treatment, e.g., the CW only work well in moderately developed regions in Hangzhou. This finding expands the environmental Kuznets law by introducing the coproduction theory into analysis (i.e., inputs from both government and residents are essential for the delivery of public goods and services such as good environmental quality). A match between technology and socioeconomic conditions is essential to the environmental governance.

Ketogenic diets and physical performance

Directory of Open Access Journals (Sweden)

Phinney SD

2004-08-01

Full Text Available Impaired physical performance is a common but not obligate result of a low carbohydrate diet. Lessons from traditional Inuit culture indicate that time for adaptation, optimized sodium and potassium nutriture, and constraint of protein to 15-25 % of daily energy expenditure allow unimpaired endurance performance despite nutritional ketosis.

Cohort profile: the Motorik-Modul Longitudinal Study: physical fitness and physical activity as determinants of health development in German children and adolescents.

Science.gov (United States)

Wagner, Matthias O; Bös, Klaus; Jekauc, Darko; Karger, Claudia; Mewes, Nadine; Oberger, Jennifer; Reimers, Anne K; Schlenker, Lars; Worth, Annette; Woll, Alexander

2014-10-01

The Motorik-Modul (MoMo) Longitudinal Study aims to contribute to long-term improvement in the health of German children and adolescents by focusing on: (i) the development of physical fitness and physical activity (including period effects); (ii) the individual and physical/social environmental determinants of the development of physical fitness and physical activity; and (iii) the impact of physical fitness and physical activity on the development of physical and mental health. The MoMo Longitudinal Study began with a nationwide representative sample of 4529 children and adolescents who ranged in age from 4-17 years at the study baseline (2003-2006). The first survey wave of the MoMo Longitudinal Study was conducted between 2009 and 2012, with two subsequent survey waves to be conducted between 2014 and 2016 and 2018 and 2020, respectively. The MoMo Longitudinal Study includes a physical fitness test profile, a physical activity questionnaire, and subjective and objective measures of health from the German Health Interview and Examination Survey (KiGGS). Data access is provided on request (alexander.woll@kit.edu). For further information, including a complete list of publications please visit www.motorik-modul.de. Published by Oxford University Press on behalf of the International Epidemiological Association © The Author 2013; all rights reserved.

Leisure time physical activity in Saudi Arabia: prevalence, pattern and determining factors.

Science.gov (United States)

Amin, Tarek Tawfik; Al Khoudair, Ali Salah; Al Harbi, Mohammad Abdulwahab; Al Ali, Ahmed Radi

2012-01-01

Identification of reliable predictors of leisure time physical activity (LTPA) will enable healthcare providers to intervene and change the patterns of LTPA in the population to improve community health. The objectives of this study were to determine prevalence and pattern of LTPA among adult Saudis aged 18-65 years, and to define the socio-demographic determinants that correlate with LTPA in Al-Hassa, Saudi Arabia. A cross-sectional study of 2176 adult Saudis attending urban and rural primary health care centers were selected using a multistage proportionate sampling method. Participants were personally interviewed to gather information regarding socio-demographics, physical activity pattern using the Global Physical Activity Questionnaire (GPAQ). Physical activity (PA) in each domain was expressed in metabolic equivalents (METs). The median total METs minutes/week for LTPA for both genders was 256, higher for men (636 METs minutes/week) compared to women (249 METs minutes/week). Overall, only 19.8% of the total PA was derived from LTPA. Of the sampled population 50.0% reported doing no leisure activity. Using the cut off of 600 METs-minutes/day or 150 minutes of moderate intensity over 5 or more days/week, only 21.0% of the included sample were considered as being sufficiently active and 10.4% were in the high active category with beneficial health effects. Multivariate regression analysis showed that male, younger age (active in the LTPA domain. The prevalence and intensity of LTPA among the included sample demonstrated low levels. Nearly 80% of the included sample population did not achieve the recommended LTPA level with beneficial health effects. Female gender, urban residence and associated chronic diseases correlated with a low LTPA.

Use of dose constraints in public exposure

International Nuclear Information System (INIS)

Tageldein, Amged

2015-02-01

An overview of the dose constraints in public exposures has been carried out in this project. The establishment, development and the application of the concept of dose constraints are reviewed with regards to public exposure. The role of dose constraints in the process of optimization of radiation protection was described and has been showed that the concept of the dose constraints along with many other concept of radiation protection is widely applied in the optimization of exposure to radiation. From the beginning of the establishment of dose constraints as a concept in radiation protection, the International Commission of Radiological Protection (ICRP) has published a number of documents that provides detailed application related to radiation protection and safety of public exposure from ionizing radiation. This work provides an overview of such publications and related documents with special emphasis on optimization of public exposure using dose constraints. (au)

Low physical activity is a determinant for elevated blood pressure in high cardiovascular risk obstructive sleep apnea.

Science.gov (United States)

Mendelson, Monique; Tamisier, Renaud; Laplaud, David; Dias-Domingos, Sonia; Baguet, Jean-Philippe; Moreau, Laurent; Koltes, Christian; Chavez, Léonidas; de Lamberterie, Gilles; Herengt, Frédéric; Levy, Patrick; Flore, Patrice; Pépin, Jean-Louis

2014-08-01

Obstructive sleep apnea (OSA) is associated with cardiovascular morbidity, including hypertension. Beyond the severity of nocturnal hypoxia, other factors such as metabolic abnormalities but also sedentary behaviors and insufficient physical activity may contribute to elevated blood pressure (BP). To clarify the respective role of these factors as determinants of BP in OSA patients, we examined the relationship between BP and anthropometrics, severity of sleep apnea, and objectively measured physical activity and sedentary behaviors. Ninety-five adults presenting with OSA (apnea-hypopnea index > 10 events/h) and high cardiovascular risk (63.3 ± 8.8 y; body mass index: 29.9 ± 4.9 kg/m(2); apnea-hypopnea index: 41.3 ± 17.5/h; cardiovascular risk score: 13.5 ± 3.7%) were included. Physical activity and sedentary behaviors were objectively assessed by actigraphy, and self-measured home BP monitoring was measured. Logistic regression models adjusted for sex, age, and body mass index were built to identify the predictors of self-measured morning and evening BP. Physical activity was significantly related to obesity but not to the severity of sleep apnea or sleepiness. Sedentary behaviors were associated with self-measured morning and evening systolic BP (r = 0.32, P = .002; r = 0.29, P = .004). Steps per day were inversely associated with evening BP (r = -0.27, P = .01). Univariate analysis identified steps/d and time spent in vigorous physical activity as determinants for evening self-measured BP. In multivariate analysis, only steps/d were identified as a significant determinant of evening BP. Physical activity is the major determinant for evening BP in adults with OSA presenting high cardiovascular risk. Our results emphasize the need for lifestyle counseling programs in combination with CPAP to encourage regular physical activity in OSA subjects to obtain better BP control. (ClinicalTrials.gov registration NCT01226641.)

Research-based assessment affordances and constraints: Perceptions of physics faculty

Science.gov (United States)

Madsen, Adrian; McKagan, Sarah B.; Martinuk, Mathew Sandy; Bell, Alexander; Sayre, Eleanor C.

2016-06-01

[This paper is part of the Focused Collection on Preparing and Supporting University Physics Educators.] To help faculty use research-based materials in a more significant way, we learn about their perceived needs and desires and use this information to suggest ways for the physics education research community to address these needs. When research-based resources are well aligned with the perceived needs of faculty, faculty members will more readily take them up. We used phenomenographic interviews of ordinary physics faculty and department chairs to identify four families of issues that faculty have around research-based assessments (RBAs). First, many faculty are interested in using RBAs but need help with the practicalities of administering RBAs: how to find them, which ones there are, and how to administer them. Second, at the same time, many faculty think that RBAs are limited and do not measure many of the things they care about, or are not applicable in their classes. They want assessments to measure skills, perceptions, and specific concepts. Third, many faculty want to turn to communities of other faculty and experts to help them interpret their assessment results and suggest other ways to do assessment. They want to better understand their assessment results by comparing to others and interacting with faculty from other schools to learn about how they do assessment. Fourth, many faculty consider their courses in the broader contexts of accountability and their departments. They want help with assessment in these broader contexts. We also discuss how a faculty member's role in their department and type of institution influence their perceived wants and needs around assessment.

Solving Large-Scale Computational Problems Using Insights from Statistical Physics

Energy Technology Data Exchange (ETDEWEB)

Selman, Bart [Cornell University

2012-02-29

Many challenging problems in computer science and related fields can be formulated as constraint satisfaction problems. Such problems consist of a set of discrete variables and a set of constraints between those variables, and represent a general class of so-called NP-complete problems. The goal is to find a value assignment to the variables that satisfies all constraints, generally requiring a search through and exponentially large space of variable-value assignments. Models for disordered systems, as studied in statistical physics, can provide important new insights into the nature of constraint satisfaction problems. Recently, work in this area has resulted in the discovery of a new method for solving such problems, called the survey propagation (SP) method. With SP, we can solve problems with millions of variables and constraints, an improvement of two orders of magnitude over previous methods.

Numerical bifurcation analysis of conformal formulations of the Einstein constraints

International Nuclear Information System (INIS)

Holst, M.; Kungurtsev, V.

2011-01-01

The Einstein constraint equations have been the subject of study for more than 50 years. The introduction of the conformal method in the 1970s as a parametrization of initial data for the Einstein equations led to increased interest in the development of a complete solution theory for the constraints, with the theory for constant mean curvature (CMC) spatial slices and closed manifolds completely developed by 1995. The first general non-CMC existence result was establish by Holst et al. in 2008, with extensions to rough data by Holst et al. in 2009, and to vacuum spacetimes by Maxwell in 2009. The non-CMC theory remains mostly open; moreover, recent work of Maxwell on specific symmetry models sheds light on fundamental nonuniqueness problems with the conformal method as a parametrization in non-CMC settings. In parallel with these mathematical developments, computational physicists have uncovered surprising behavior in numerical solutions to the extended conformal thin sandwich formulation of the Einstein constraints. In particular, numerical evidence suggests the existence of multiple solutions with a quadratic fold, and a recent analysis of a simplified model supports this conclusion. In this article, we examine this apparent bifurcation phenomena in a methodical way, using modern techniques in bifurcation theory and in numerical homotopy methods. We first review the evidence for the presence of bifurcation in the Hamiltonian constraint in the time-symmetric case. We give a brief introduction to the mathematical framework for analyzing bifurcation phenomena, and then develop the main ideas behind the construction of numerical homotopy, or path-following, methods in the analysis of bifurcation phenomena. We then apply the continuation software package AUTO to this problem, and verify the presence of the fold with homotopy-based numerical methods. We discuss these results and their physical significance, which lead to some interesting remaining questions to

Promoting physical activity: development and testing of self-determination theory-based interventions

Science.gov (United States)

2012-01-01

A growing number of studies have pulled from Deci and Ryan's Self-Determination Theory to design interventions targeting health behavior change. More recently, researchers have begun using SDT to promote the adoption and maintenance of an active lifestyle. In this review, we aim to highlight how researchers and practitioners can draw from the SDT framework to develop, implement, and evaluate intervention efforts centered on increasing physical activity levels in different contexts and different populations. In the present paper, the rationale for using SDT to foster physical activity engagement is briefly reviewed before particular attention is given to three recent randomized controlled trials, the Canadian Physical Activity Counseling (PAC) Trial, the Empower trial from the UK, and the Portuguese PESO (Promotion of Health and Exercise in Obesity) trial, each of which focused on promoting physical activity behavior. The SDT-based intervention components, procedures, and participants are highlighted, and the key findings that have emanated from these three trials are presented. Lastly, we outline some of the limitations of the work conducted to date in this area and we acknowledge the challenges that arise when attempting to design, deliver, and test SDT-grounded interventions in the context of physical activity promotion. PMID:22385751

Determinants of Perceived Physical Environment Barriers among Community-Dwelling Elderly in Taiwan.

Science.gov (United States)

Lien, W-C; Chang, J-H; Guo, N-W; Lin, Y-C; Hsieh, P-C; Kuan, T-S

2015-05-01

To test the hypothesis that mobility, activities of daily living, and the interaction between them can play a key role in determining perceived physical environment barriers among community-dwelling elderly. Cross-sectional. Community. One hundred and ninety-seven community-dwelling elderly with more than 7 points on the Short Portable Mental State Questionnaire and less than 7 points on the Geriatric Depression Scale (15 items). None. Time Get-up and Go test (TUG), the subscales of basic activity of daily living (BADL)/instrumental activities of daily living (IADL) of the Hierarchy of Care Required (HCR), and the physical/structural subscale of the Craig Hospital Inventory of Environmental Factors in Community-dwelling Elderly in Taiwan were used to measure mobility, activities of daily living and perceived physical environment barriers, respectively. Hierarchical linear regression analyses were used to test the study hypothesis. Significant and positive relations were found to exist between perceived physical environment barriers and (1) the TUG time (β=.300, pdwelling elderly under consideration. Strategies targeting the enhancement of mobility among community-dwelling elderly are suggested to lead to improvements in the degree to which physical environment barriers are perceived. This beneficial effect could be greater in the case of elderly individuals with better IADL function.

A general treatment of dynamic integrity constraints

NARCIS (Netherlands)

de Brock, EO

This paper introduces a general, set-theoretic model for expressing dynamic integrity constraints, i.e., integrity constraints on the state changes that are allowed in a given state space. In a managerial context, such dynamic integrity constraints can be seen as representations of "real world"

Gauge transformations in relativistic two-particle constraint theory

International Nuclear Information System (INIS)

Jallouli, H.; Sazdjian, H.

1996-01-01

The forms of the local potentials in linear covariant gauges are investigated and relationships are found between them. The gauge transformation properties of the Green's function and of the Bethe-Salpeter wave function are reviewed. The infinitesimal gauge transformation laws of the constraint theory wave functions and potentials are determined. The case of the local approximation of potentials is considered. The general properties of the gauge transformations in the local approximation are studied. (K.A.)

An Introduction to 'Creativity Constraints'

DEFF Research Database (Denmark)

Onarheim, Balder; Biskjær, Michael Mose

2013-01-01

Constraints play a vital role as both restrainers and enablers in innovation processes by governing what the creative agent/s can and cannot do, and what the output can and cannot be. Notions of constraints are common in creativity research, but current contributions are highly dispersed due to n...

Market segmentation using perceived constraints

Science.gov (United States)

Jinhee Jun; Gerard Kyle; Andrew Mowen

2008-01-01

We examined the practical utility of segmenting potential visitors to Cleveland Metroparks using their constraint profiles. Our analysis identified three segments based on their scores on the dimensions of constraints: Other priorities--visitors who scored the highest on 'other priorities' dimension; Highly Constrained--visitors who scored relatively high on...

Constraint Handling Rules with Binders, Patterns and Generic Quantification

NARCIS (Netherlands)

Serrano, Alejandro; Hage, J.

2017-01-01

Constraint Handling Rules provide descriptions for constraint solvers. However, they fall short when those constraints specify some binding structure, like higher-rank types in a constraint-based type inference algorithm. In this paper, the term syntax of constraints is replaced by λ-tree syntax, in

Constraints to 3R construction waste reduction among contractors in Penang

Science.gov (United States)

Ng, L. S.; Tan, L. W.; Seow, T. W.

2018-04-01

Rapid development of construction industry increases construction waste on landfill leading to shorter life span of the landfill. Waste reduction through Reduce, Reuse and Recycle (3R) practice has been encouraged in construction industry towards sustainable waste management since couple of decades ago. However, waste reduction through 3R is still at its infancy in construction industry in Penang, Malaysia. The aim of this paper is to determinate the constraints to construction waste reduction through 3R among contractors in Penang. The findings reported herein is based on feedbacks from 143 construction contractors of grade CIDB G7, G6 and G5 based in Penang, experts from Penang Local Authority, CIDB in Penang and its headquarters, National Solid Waste Management Department, and headquarters of Solid Waste and Public Cleansing Management Corporation (SWCorp). Based on interviews and questionnaire surveys, constraints identified are Time and cost, Contractor’s attitude and low participation, Lack of enforcement law and regulation, Lack of awareness and knowledge, Lack of coordination, and Lack of space. Awareness and knowledge, and enforcement law and regulation are the major barriers which influence others constraints as well. Therefore, these constraints should be emphasized by the authorities in order to improve the implementation of 3R construction waste reduction.

Ketogenic diets and physical performance

Directory of Open Access Journals (Sweden)

Phinney Stephen D

2004-08-01

Full Text Available Abstract Impaired physical performance is a common but not obligate result of a low carbohydrate diet. Lessons from traditional Inuit culture indicate that time for adaptation, optimized sodium and potassium nutriture, and constraint of protein to 15–25 % of daily energy expenditure allow unimpaired endurance performance despite nutritional ketosis.

A Model for the Two-dimensional no Isolated Bits Constraint

DEFF Research Database (Denmark)

Forchhammer, Søren; Laursen, Torben Vaarby

2006-01-01

A stationary model is presented for the two-dimensional (2-D) no isolated bits (n.i.b.) constraint over an extended alphabet defined by the elements within 1 by 2 blocks. This block-wise model is based on a set of sufficient conditions for a Pickard random field (PRF) over an m-ary alphabet....... Iterative techniques are applied as part of determining the model parameters. Given two Markov chains describing a boundary, an algorithm is presented which determines whether a certain PRF consistent with the boundary exists. Iterative scaling is used as part of the algorithm, which also determines...

Motivation, participation and performance in physical education: A self-determination approach.

OpenAIRE

Langøy, Amund

2014-01-01

Introduction: Within the academic field there has been given increasing attention to motivation in physical education (PE). In the current study a Self-Determination Theory (SDT) model was tested in which (1) perceived autonomy support from teachers were hypothesized to be positively associated with students’ needs satisfaction, (2) which was expected to be positively associated with autonomous motivation and (3) negatively associated with amotivation. Further, (4) autonomous motivation was h...

Respiratory Constraints in Verbal and Non-verbal Communication.

Science.gov (United States)

Włodarczak, Marcin; Heldner, Mattias

2017-01-01

In the present paper we address the old question of respiratory planning in speech production. We recast the problem in terms of speakers' communicative goals and propose that speakers try to minimize respiratory effort in line with the H&H theory. We analyze respiratory cycles coinciding with no speech (i.e., silence), short verbal feedback expressions (SFE's) as well as longer vocalizations in terms of parameters of the respiratory cycle and find little evidence for respiratory planning in feedback production. We also investigate timing of speech and SFEs in the exhalation and contrast it with nods. We find that while speech is strongly tied to the exhalation onset, SFEs are distributed much more uniformly throughout the exhalation and are often produced on residual air. Given that nods, which do not have any respiratory constraints, tend to be more frequent toward the end of an exhalation, we propose a mechanism whereby respiratory patterns are determined by the trade-off between speakers' communicative goals and respiratory constraints.

Elementary computer physics, a concentrated one-week course

DEFF Research Database (Denmark)

Christiansen, Gunnar Dan

1978-01-01

A concentrated one-week course (8 hours per day in 5 days) in elementary computer physics for students in their freshman university year is described. The aim of the course is to remove the constraints on traditional physics courses imposed by the necessity of only dealing with problems that have...... fields, and a lunar space vehicle are used as examples....

arXiv Flavour Physics and CP Violation

CERN Document Server

Kamenik, J.F.

2016-01-01

These notes represent a summary of three lectures on flavour and CP violation, given at the CERNs European School of High Energy Physics in 2014. They cover flavour physics within the standard model, phenomenology of CP violation in meson mixing and decays, as well as constraints of flavour observableson physics beyond the standard model. In preparing the lectures (and consequently this summary) I drew heavily from several existing excellent and exhaustive sets of lecture notes and reviews on flavour physics and CP violation [1]. The reader is encouraged to consult those as well as the original literature for a more detailed study.

Recent Results on Top Physics in CMS

CERN Multimedia

CERN. Geneva

2012-01-01

Top physics is a pillar of the physics programme at the LHC. It involves precision measurements, leading to constraints on standard model parameters, as well as many measurements of observables sensitive to new physics. In this seminar, an overview of measurements performed by the CMS experiment in the domain of top physics will be presented, based on pp data collected in 2011 at a center-of-mass energy of 7 TeV. The results will be compared to expectations from theory. Emphasis in will be given to more recent results and to the treatment of systematic uncertainties.

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

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......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...

Toward an automaton Constraint for Local Search

Directory of Open Access Journals (Sweden)

Jun He

2009-10-01

Full Text Available We explore the idea of using finite automata to implement new constraints for local search (this is already a successful technique in constraint-based global search. We show how it is possible to maintain incrementally the violations of a constraint and its decision variables from an automaton that describes a ground checker for that constraint. We establish the practicality of our approach idea on real-life personnel rostering problems, and show that it is competitive with the approach of [Pralong, 2007].

Effects of Contingency versus Constraints on the Body-Mass Scaling of Metabolic Rate

Directory of Open Access Journals (Sweden)

Douglas S. Glazier

2018-01-01

Full Text Available I illustrate the effects of both contingency and constraints on the body-mass scaling of metabolic rate by analyzing the significantly different influences of ambient temperature (Ta on metabolic scaling in ectothermic versus endothermic animals. Interspecific comparisons show that increasing Ta results in decreasing metabolic scaling slopes in ectotherms, but increasing slopes in endotherms, a pattern uniquely predicted by the metabolic-level boundaries hypothesis, as amended to include effects of the scaling of thermal conductance in endotherms outside their thermoneutral zone. No other published theoretical model explicitly predicts this striking variation in metabolic scaling, which I explain in terms of contingent effects of Ta and thermoregulatory strategy in the context of physical and geometric constraints related to the scaling of surface area, volume, and heat flow across surfaces. My analysis shows that theoretical models focused on an ideal 3/4-power law, as explained by a single universally applicable mechanism, are clearly inadequate for explaining the diversity and environmental sensitivity of metabolic scaling. An important challenge is to develop a theory of metabolic scaling that recognizes the contingent effects of multiple mechanisms that are modulated by several extrinsic and intrinsic factors within specified constraints.

Constraint-based Attribute and Interval Planning

Science.gov (United States)

Jonsson, Ari; Frank, Jeremy

2013-01-01

In this paper we describe Constraint-based Attribute and Interval Planning (CAIP), a paradigm for representing and reasoning about plans. The paradigm enables the description of planning domains with time, resources, concurrent activities, mutual exclusions among sets of activities, disjunctive preconditions and conditional effects. We provide a theoretical foundation for the paradigm, based on temporal intervals and attributes. We then show how the plans are naturally expressed by networks of constraints, and show that the process of planning maps directly to dynamic constraint reasoning. In addition, we de ne compatibilities, a compact mechanism for describing planning domains. We describe how this framework can incorporate the use of constraint reasoning technology to improve planning. Finally, we describe EUROPA, an implementation of the CAIP framework.

Constraints on stress-energy perturbations in general relativity

International Nuclear Information System (INIS)

Traschen, J.

1985-01-01

Conditions are found for the existence of integral constraints on stress-energy perturbations in general relativity. The integral constraints can be thought of as a general-relativistic generalization of the conservation of energy and momentum of matter perturbations in special relativity. The constraints are stated in terms of a vector field V, and the Robertson-Walker spacetimes are shown to have such constraint vectors. Although in general V is not a Killing vector, in a vacuum spacetime the constraint vectors are precisely the Killing vectors

On Lifecycle Constraints of Artifact-Centric Workflows

Science.gov (United States)

Kucukoguz, Esra; Su, Jianwen

Data plays a fundamental role in modeling and management of business processes and workflows. Among the recent "data-aware" workflow models, artifact-centric models are particularly interesting. (Business) artifacts are the key data entities that are used in workflows and can reflect both the business logic and the execution states of a running workflow. The notion of artifacts succinctly captures the fluidity aspect of data during workflow executions. However, much of the technical dimension concerning artifacts in workflows is not well understood. In this paper, we study a key concept of an artifact "lifecycle". In particular, we allow declarative specifications/constraints of artifact lifecycle in the spirit of DecSerFlow, and formulate the notion of lifecycle as the set of all possible paths an artifact can navigate through. We investigate two technical problems: (Compliance) does a given workflow (schema) contain only lifecycle allowed by a constraint? And (automated construction) from a given lifecycle specification (constraint), is it possible to construct a "compliant" workflow? The study is based on a new formal variant of artifact-centric workflow model called "ArtiNets" and two classes of lifecycle constraints named "regular" and "counting" constraints. We present a range of technical results concerning compliance and automated construction, including: (1) compliance is decidable when workflow is atomic or constraints are regular, (2) for each constraint, we can always construct a workflow that satisfies the constraint, and (3) sufficient conditions where atomic workflows can be constructed.

Dark matter physics, flavor physics and LHC constraints in the dark matter model with a bottom partner

Energy Technology Data Exchange (ETDEWEB)

Abe, Tomohiro [Institute for Advanced Research, Nagoya University,Nagoya 464-8602 (Japan); Kobayashi-Maskawa Institute for the Origin of Particles and the Universe,Nagoya University, Nagoya 464-8602 (Japan); Kawamura, Junichiro [Department of Physics, Waseda University,Tokyo 169-8555 (Japan); Okawa, Shohei [Department of Physics, Nagoya University,Nagoya 464-8602 (Japan); Omura, Yuji [Kobayashi-Maskawa Institute for the Origin of Particles and the Universe,Nagoya University, Nagoya 464-8602 (Japan)

2017-03-10

In the scenario that dark matter (DM) is a weakly interacting massive particle, there are many possibilities of the interactions with the Standard Model (SM) particles to achieve the relic density of DM. In this paper, we consider a simple DM model where the DM candidate is a complex scalar boson. The model contains a new complex gauge singlet scalar boson and a new fermion whose gauge charge is the same as the right-handed down-type quark. We dub the new fermion the bottom partner. These new particles have Yukawa interactions with the SM down-type quarks. The DM candidate interacts with the SM particles through the Yukawa interactions. The Yukawa interactions are not only relevant to the annihilation process of the DM but also contribute to the flavor physics, such as the ΔF=2 processes. In addition, the flavor alignment of the Yukawa couplings is related to the decay modes of the bottom partner, and thus we can find the explicit correlations among the physical observables in DM physics, flavor physics, and the signals at the LHC. We survey the ΔF=2 processes based on the numerical analyses of the thermal relic density, the direct detection of the DM, and the current LHC bounds. We investigate the perturbative bound on the Yukawa coupling as well. A Study of a fermionic DM model with extra scalar quarks is also given for comparison.

The roles of constraint-based and dedication-based influences on user's continued online shopping behavior.

Science.gov (United States)

Chang, Su-Chao; Chou, Chi-Min

2012-11-01

The objective of this study was to determine empirically the role of constraint-based and dedication-based influences as drivers of the intention to continue using online shopping websites. Constraint-based influences consist of two variables: trust and perceived switching costs. Dedication-based influences consist of three variables: satisfaction, perceived usefulness, and trust. The current results indicate that both constraint-based and dedication-based influences are important drivers of the intention to continue using online shopping websites. The data also shows that trust has the strongest total effect on online shoppers' intention to continue using online shopping websites. In addition, the results indicate that the antecedents of constraint-based influences, technical bonds (e.g., perceived operational competence and perceived website interactivity) and social bonds (e.g., perceived relationship investment, community building, and intimacy) have indirect positive effects on the intention to continue using online shopping websites. Based on these findings, this research suggests that online shopping websites should build constraint-based and dedication-based influences to enhance user's continued online shopping behaviors simultaneously.

Status of Neutrino Properties and Future Prospects—Cosmological and Astrophysical Constraints

Directory of Open Access Journals (Sweden)

Martina Gerbino

2018-02-01

Full Text Available Cosmological observations are a powerful probe of neutrino properties, and in particular of their mass. In this review, we first discuss the role of neutrinos in shaping the cosmological evolution at both the background and perturbation level, and describe their effects on cosmological observables such as the cosmic microwave background and the distribution of matter at large scale. We then present the state of the art concerning the constraints on neutrino masses from those observables, and also review the prospects for future experiments. We also briefly discuss the prospects for determining the neutrino hierarchy from cosmology, the complementarity with laboratory experiments, and the constraints on neutrino properties beyond their mass.

Constraints on alternate universes: stars and habitable planets with different fundamental constants

International Nuclear Information System (INIS)

Adams, Fred C.

2016-01-01

This paper develops constraints on the values of the fundamental constants that allow universes to be habitable. We focus on the fine structure constant α and the gravitational structure constant α G , and find the region in the α-α G plane that supports working stars and habitable planets. This work is motivated, in part, by the possibility that different versions of the laws of physics could be realized within other universes. The following constraints are enforced: [A] long-lived stable nuclear burning stars exist, [B] planetary surface temperatures are hot enough to support chemical reactions, [C] stellar lifetimes are long enough to allow biological evolution, [D] planets are massive enough to maintain atmospheres, [E] planets are small enough in mass to remain non-degenerate, [F] planets are massive enough to support sufficiently complex biospheres, [G] planets are smaller in mass than their host stars, and [H] stars are smaller in mass than their host galaxies. This paper delineates the portion of the α-α G plane that satisfies all of these constraints. The results indicate that viable universes—with working stars and habitable planets—can exist within a parameter space where the structure constants α and α G vary by several orders of magnitude. These constraints also provide upper bounds on the structure constants (α,α G ) and their ratio. We find the limit α G /α ∼< 10 −34 , which shows that habitable universes must have a large hierarchy between the strengths of the gravitational force and the electromagnetic force

Constraints on alternate universes: stars and habitable planets with different fundamental constants

Energy Technology Data Exchange (ETDEWEB)

Adams, Fred C., E-mail: fca@umich.edu [Physics Department, University of Michigan, 450 Church Street, Ann Arbor, MI 48109 (United States)

2016-02-01

This paper develops constraints on the values of the fundamental constants that allow universes to be habitable. We focus on the fine structure constant α and the gravitational structure constant α{sub G}, and find the region in the α-α{sub G} plane that supports working stars and habitable planets. This work is motivated, in part, by the possibility that different versions of the laws of physics could be realized within other universes. The following constraints are enforced: [A] long-lived stable nuclear burning stars exist, [B] planetary surface temperatures are hot enough to support chemical reactions, [C] stellar lifetimes are long enough to allow biological evolution, [D] planets are massive enough to maintain atmospheres, [E] planets are small enough in mass to remain non-degenerate, [F] planets are massive enough to support sufficiently complex biospheres, [G] planets are smaller in mass than their host stars, and [H] stars are smaller in mass than their host galaxies. This paper delineates the portion of the α-α{sub G} plane that satisfies all of these constraints. The results indicate that viable universes—with working stars and habitable planets—can exist within a parameter space where the structure constants α and α{sub G} vary by several orders of magnitude. These constraints also provide upper bounds on the structure constants (α,α{sub G}) and their ratio. We find the limit α{sub G}/α ∼< 10{sup −34}, which shows that habitable universes must have a large hierarchy between the strengths of the gravitational force and the electromagnetic force.

Combined constraints on the structure and physical properties of the East Antarctic lithosphere from geology and geophysics.

Science.gov (United States)

Reading, A. M.; Staal, T.; Halpin, J.; Whittaker, J. M.; Morse, P. E.

2017-12-01

The lithosphere of East Antarctica is one of the least explored regions of the planet, yet it is gaining in importance in global scientific research. Continental heat flux density and 3D glacial isostatic adjustment studies, for example, rely on a good knowledge of the deep structure in constraining model inputs.In this contribution, we use a multidisciplinary approach to constrain lithospheric domains. To seismic tomography models, we add constraints from magnetic studies and also new geological constraints. Geological knowledge exists around the periphery of East Antarctica and is reinforced in the knowledge of plate tectonic reconstructions. The subglacial geology of the Antarctic hinterland is largely unknown but the plate reconstructions allow the well-posed extrapolation of major terranes into the interior of the continent, guided by the seismic tomography and magnetic images. We find that the northern boundary of the lithospheric domain centred on the Gamburtsev Subglacial Mountains has a possible trend that runs south of the Lambert Glacier region, turning coastward through Wilkes Land. Other periphery-to-interior connections are less well constrained and the possibility of lithospheric domains that are entirely sub-glacial is high. We develop this framework to include a probabilistic method of handling alternate models and quantifiable uncertainties. We also show first results in using a Bayesian approach to predicting lithospheric boundaries from multivariate data.Within the newly constrained domains, we constrain heat flux (density) as the sum of basal heat flux and upper crustal heat flux. The basal heat flux is constrained by geophysical methods while the upper crustal heat flux is constrained by geology or predicted geology. In addition to heat flux constraints, we also consider the variations in friction experienced by moving ice sheets due to varying geology.

Physical and social factors determining quality of life for veterans with lower-limb amputation(s)

DEFF Research Database (Denmark)

Christensen, Jan; Ipsen, Thomas; Doherty, Patrick

2016-01-01

of the literature to summarize any evidence on the physical and social determinants for HRQoL in veterans with uni- or bilateral lower-limb amputation(s). Method MEDLINE, EMBASE, PEDro, CINAHL, Scopus and Cochrane databases were searched systematically for eligible studies. Inclusion criteria were: traumatic lower......-limb amputation(s), HRQoL outcome and veterans. Physical and social factors that influence HRQoL were extracted. Results The literature search identified 2073 citations, leading to the inclusion of 10 studies in the systematic review. Physical activity level, sport participation, level of amputation, back pain...

Revisiting the simplicity constraints and coherent intertwiners

International Nuclear Information System (INIS)

Dupuis, Maite; Livine, Etera R

2011-01-01

In the context of loop quantum gravity and spinfoam models, the simplicity constraints are essential in that they allow one to write general relativity as a constrained topological BF theory. In this work, we apply the recently developed U(N) framework for SU(2) intertwiners to the issue of imposing the simplicity constraints to spin network states. More particularly, we focus on solving on individual intertwiners in the 4D Euclidean theory. We review the standard way of solving the simplicity constraints using coherent intertwiners and we explain how these fit within the U(N) framework. Then we show how these constraints can be written as a closed u(N) algebra and we propose a set of U(N) coherent states that solves all the simplicity constraints weakly for an arbitrary Immirzi parameter.

Determination of Eros Physical Parameters for Near Earth Asteroid Rendezvous Orbit Phase Navigation

Science.gov (United States)

Miller, J. K.; Antreasian, P. J.; Georgini, J.; Owen, W. M.; Williams, B. G.; Yeomans, D. K.

1995-01-01

Navigation of the orbit phase of the Near Earth steroid Rendezvous (NEAR) mission will re,quire determination of certain physical parameters describing the size, shape, gravity field, attitude and inertial properties of Eros. Prior to launch, little was known about Eros except for its orbit which could be determined with high precision from ground based telescope observations. Radar bounce and light curve data provided a rough estimate of Eros shape and a fairly good estimate of the pole, prime meridian and spin rate. However, the determination of the NEAR spacecraft orbit requires a high precision model of Eros's physical parameters and the ground based data provides only marginal a priori information. Eros is the principal source of perturbations of the spacecraft's trajectory and the principal source of data for determining the orbit. The initial orbit determination strategy is therefore concerned with developing a precise model of Eros. The original plan for Eros orbital operations was to execute a series of rendezvous burns beginning on December 20,1998 and insert into a close Eros orbit in January 1999. As a result of an unplanned termination of the rendezvous burn on December 20, 1998, the NEAR spacecraft continued on its high velocity approach trajectory and passed within 3900 km of Eros on December 23, 1998. The planned rendezvous burn was delayed until January 3, 1999 which resulted in the spacecraft being placed on a trajectory that slowly returns to Eros with a subsequent delay of close Eros orbital operations until February 2001. The flyby of Eros provided a brief glimpse and allowed for a crude estimate of the pole, prime meridian and mass of Eros. More importantly for navigation, orbit determination software was executed in the landmark tracking mode to determine the spacecraft orbit and a preliminary shape and landmark data base has been obtained. The flyby also provided an opportunity to test orbit determination operational procedures that will be

Strong binary pulsar constraints on Lorentz violation in gravity.

Science.gov (United States)

Yagi, Kent; Blas, Diego; Yunes, Nicolás; Barausse, Enrico

2014-04-25

Binary pulsars are excellent laboratories to test the building blocks of Einstein's theory of general relativity. One of these is Lorentz symmetry, which states that physical phenomena appear the same for all inertially moving observers. We study the effect of violations of Lorentz symmetry in the orbital evolution of binary pulsars and find that it induces a much more rapid decay of the binary's orbital period due to the emission of dipolar radiation. The absence of such behavior in recent observations allows us to place the most stringent constraints on Lorentz violation in gravity, thus verifying one of the cornerstones of Einstein's theory much more accurately than any previous gravitational observation.

Strong Binary Pulsar Constraints on Lorentz Violation in Gravity

CERN Document Server

Yagi, Kent; Yunes, Nicolas; Barausse, Enrico

2014-01-01

Binary pulsars are excellent laboratories to test the building blocks of Einstein's theory of General Relativity. One of these is Lorentz symmetry which states that physical phenomena appear the same for all inertially moving observers. We study the effect of violations of Lorentz symmetry in the orbital evolution of binary pulsars and find that it induces a much more rapid decay of the binary's orbital period due to the emission of dipolar radiation. The absence of such behavior in recent observations allows us to place the most stringent constraints on Lorentz violation in gravity, thus verifying one of the cornerstones of Einstein's theory much more accurately than any previous gravitational observation.

The Ambiguous Role of Constraints in Creativity

DEFF Research Database (Denmark)

Biskjær, Michael Mose; Onarheim, Balder; Wiltschnig, Stefan

2011-01-01

The relationship between creativity and constraints is often described in the literature either in rather imprecise, general concepts or in relation to very specific domains. Cross-domain and cross-disciplinary takes on how the handling of constraints influences creative activities are rare. In t......-disciplinary research into the ambiguous role of constraints in creativity....

PROBING THE INFLATON: SMALL-SCALE POWER SPECTRUM CONSTRAINTS FROM MEASUREMENTS OF THE COSMIC MICROWAVE BACKGROUND ENERGY SPECTRUM

International Nuclear Information System (INIS)

Chluba, Jens; Erickcek, Adrienne L.; Ben-Dayan, Ido

2012-01-01

In the early universe, energy stored in small-scale density perturbations is quickly dissipated by Silk damping, a process that inevitably generates μ- and y-type spectral distortions of the cosmic microwave background (CMB). These spectral distortions depend on the shape and amplitude of the primordial power spectrum at wavenumbers k ∼ 4 Mpc –1 . Here, we study constraints on the primordial power spectrum derived from COBE/FIRAS and forecasted for PIXIE. We show that measurements of μ and y impose strong bounds on the integrated small-scale power, and we demonstrate how to compute these constraints using k-space window functions that account for the effects of thermalization and dissipation physics. We show that COBE/FIRAS places a robust upper limit on the amplitude of the small-scale power spectrum. This limit is about three orders of magnitude stronger than the one derived from primordial black holes in the same scale range. Furthermore, this limit could be improved by another three orders of magnitude with PIXIE, potentially opening up a new window to early universe physics. To illustrate the power of these constraints, we consider several generic models for the small-scale power spectrum predicted by different inflation scenarios, including running-mass inflation models and inflation scenarios with episodes of particle production. PIXIE could place very tight constraints on these scenarios, potentially even ruling out running-mass inflation models if no distortion is detected. We also show that inflation models with sub-Planckian field excursion that generate detectable tensor perturbations should simultaneously produce a large CMB spectral distortion, a link that could potentially be established with PIXIE.

Constraints on the Lee-Wick Higgs sector

International Nuclear Information System (INIS)

Carone, Christopher D.; Primulando, Reinard

2009-01-01

Lee-Wick partners to the standard model Higgs doublet may appear at a mass scale that is significantly lower than that of the remaining Lee-Wick partner states. The relevant effective theory is a two-Higgs doublet model in which one doublet has wrong-sign kinetic and mass terms. We determine bounds on this effective theory, including those from neutral B-meson mixing, b→X s γ, and Z→bb. The results differ from those of conventional two-Higgs doublet models and lead to meaningful constraints on the Lee-Wick Higgs sector.

Low-energy photo- and electroproduction for physical pions

International Nuclear Information System (INIS)

MacMullen, J.T.

1979-02-01

The Ward identities of current algebra are combined with gauge invariance constraints, on-shell PCAC and the Bjorken limit to obtain the low-energy expressions of the pion photo- and electroproduction invariant amplitudes for physical pions

Constraint, Intelligence, and Control Hierarchy in Virtual Environments. Chapter 1

Science.gov (United States)

Sheridan, Thomas B.

2007-01-01

This paper seeks to deal directly with the question of what makes virtual actors and objects that are experienced in virtual environments seem real. (The term virtual reality, while more common in public usage, is an oxymoron; therefore virtual environment is the preferred term in this paper). Reality is difficult topic, treated for centuries in those sub-fields of philosophy called ontology- "of or relating to being or existence" and epistemology- "the study of the method and grounds of knowledge, especially with reference to its limits and validity" (both from Webster s, 1965). Advances in recent decades in the technologies of computers, sensors and graphics software have permitted human users to feel present or experience immersion in computer-generated virtual environments. This has motivated a keen interest in probing this phenomenon of presence and immersion not only philosophically but also psychologically and physiologically in terms of the parameters of the senses and sensory stimulation that correlate with the experience (Ellis, 1991). The pages of the journal Presence: Teleoperators and Virtual Environments have seen much discussion of what makes virtual environments seem real (see, e.g., Slater, 1999; Slater et al. 1994; Sheridan, 1992, 2000). Stephen Ellis, when organizing the meeting that motivated this paper, suggested to invited authors that "We may adopt as an organizing principle for the meeting that the genesis of apparently intelligent interaction arises from an upwelling of constraints determined by a hierarchy of lower levels of behavioral interaction. "My first reaction was "huh?" and my second was "yeah, that seems to make sense." Accordingly the paper seeks to explain from the author s viewpoint, why Ellis s hypothesis makes sense. What is the connection of "presence" or "immersion" of an observer in a virtual environment, to "constraints" and what types of constraints. What of "intelligent interaction," and is it the intelligence of the

Fixed Costs and Hours Constraints

Science.gov (United States)

Johnson, William R.

2011-01-01

Hours constraints are typically identified by worker responses to questions asking whether they would prefer a job with more hours and more pay or fewer hours and less pay. Because jobs with different hours but the same rate of pay may be infeasible when there are fixed costs of employment or mandatory overtime premia, the constraint in those…

Newer developments on self-modeling curve resolution implementing equality and unimodality constraints.

Science.gov (United States)

Beyramysoltan, Samira; Abdollahi, Hamid; Rajkó, Róbert

2014-05-27

Analytical self-modeling curve resolution (SMCR) methods resolve data sets to a range of feasible solutions using only non-negative constraints. The Lawton-Sylvestre method was the first direct method to analyze a two-component system. It was generalized as a Borgen plot for determining the feasible regions in three-component systems. It seems that a geometrical view is required for considering curve resolution methods, because the complicated (only algebraic) conceptions caused a stop in the general study of Borgen's work for 20 years. Rajkó and István revised and elucidated the principles of existing theory in SMCR methods and subsequently introduced computational geometry tools for developing an algorithm to draw Borgen plots in three-component systems. These developments are theoretical inventions and the formulations are not always able to be given in close form or regularized formalism, especially for geometric descriptions, that is why several algorithms should have been developed and provided for even the theoretical deductions and determinations. In this study, analytical SMCR methods are revised and described using simple concepts. The details of a drawing algorithm for a developmental type of Borgen plot are given. Additionally, for the first time in the literature, equality and unimodality constraints are successfully implemented in the Lawton-Sylvestre method. To this end, a new state-of-the-art procedure is proposed to impose equality constraint in Borgen plots. Two- and three-component HPLC-DAD data set were simulated and analyzed by the new analytical curve resolution methods with and without additional constraints. Detailed descriptions and explanations are given based on the obtained abstract spaces. Copyright © 2014 Elsevier B.V. All rights reserved.

Constraints on the scale of toroidal-fusion experiments with application to the design of a helical-axis stellarator

International Nuclear Information System (INIS)

Noterdaeme, J.M.

1983-05-01

Applying the constraints to the design of a helical axis stellarator we find a limit on the combination of toroidal field, current density and major radius. Another major constraint for this concept is the ability to obtain the plasma physics parameters dictated by similarity considerations. This depends on the heating method used. A minimum scale experiment with 2 periods and no linkage of the toroidal and poloidal coils, would have a major radius of 1.2m, a toroidal field of 3.5T and 2MW of ECRH power (for β = 1% nu 2 = 10)

Energetic constraints, size gradients, and size limits in benthic marine invertebrates.

Science.gov (United States)

Sebens, Kenneth P

2002-08-01

Populations of marine benthic organisms occupy habitats with a range of physical and biological characteristics. In the intertidal zone, energetic costs increase with temperature and aerial exposure, and prey intake increases with immersion time, generating size gradients with small individuals often found at upper limits of distribution. Wave action can have similar effects, limiting feeding time or success, although certain species benefit from wave dislodgment of their prey; this also results in gradients of size and morphology. The difference between energy intake and metabolic (and/or behavioral) costs can be used to determine an energetic optimal size for individuals in such populations. Comparisons of the energetic optimal size to the maximum predicted size based on mechanical constraints, and the ensuing mortality schedule, provides a mechanism to study and explain organism size gradients in intertidal and subtidal habitats. For species where the energetic optimal size is well below the maximum size that could persist under a certain set of wave/flow conditions, it is probable that energetic constraints dominate. When the opposite is true, populations of small individuals can dominate habitats with strong dislodgment or damage probability. When the maximum size of individuals is far below either energetic optima or mechanical limits, other sources of mortality (e.g., predation) may favor energy allocation to early reproduction rather than to continued growth. Predictions based on optimal size models have been tested for a variety of intertidal and subtidal invertebrates including sea anemones, corals, and octocorals. This paper provides a review of the optimal size concept, and employs a combination of the optimal energetic size model and life history modeling approach to explore energy allocation to growth or reproduction as the optimal size is approached.

Micro-economic analysis of the physical constrained markets: game theory application to competitive electricity markets

Energy Technology Data Exchange (ETDEWEB)

Bompard, E.; Ma, Y.C. [Politecnico di Torino, Dept. of Electrical Engineering, Torino (Italy); Ragazzi, E. [CERIS, Institute for Economic Research on Firms and Growth, CNR, National Research Council, Moncalieri, TO (Italy)

2006-03-15

Competition has been introduced in the electricity markets with the goal of reducing prices and improving efficiency. The basic idea which stays behind this choice is that, in competitive markets, a greater quantity of the good is exchanged at a lower price, leading to higher market efficiency. Electricity markets are pretty different from other commodities mainly due to the physical constraints related to the network structure that may impact the market performance. The network structure of the system on which the economic transactions needs to be undertaken poses strict physical and operational constraints. Strategic interactions among producers that game the market with the objective of maximizing their producer surplus must be taken into account when modeling competitive electricity markets. The physical constraints, specific of the electricity markets, provide additional opportunity of gaming to the market players. Game theory provides a tool to model such a context. This paper discussed the application of game theory to physical constrained electricity markets with the goal of providing tools for assessing the market performance and pinpointing the critical network constraints that may impact the market efficiency. The basic models of game theory specifically designed to represent the electricity markets will be presented. IEEE30 bus test system of the constrained electricity market will be discussed to show the network impacts on the market performances in presence of strategic bidding behavior of the producers. (authors)