WorldWideScience

Sample records for marginal stability diagrams

  1. On the Marginal Stability of Glassy Systems

    Science.gov (United States)

    Yan, Le; Baity-Jesi, Marco; Müller, Markus; Wyart, Matthieu

    2015-03-01

    In various glassy systems that are out of equilibrium, like spin glasses and granular packings, the dynamics appears to be critical: avalanches involving almost the whole system could happen. A recent conceptual breakthrough argues that such glassy systems sample the ensemble of marginal stable states, which inevitably results into critical dynamics. However, it is unclear how the marginal stability is dynamically guaranteed. We investigate this marginal stability assumption by studying specifically the critical athermal dynamics of the Sherrington-Kirkpatrick model. We discuss how a pseudo-gap in the density distribution of local fields characterizing the marginal stability arises dynamically.

  2. Algorithms for computing the multivariable stability margin

    Science.gov (United States)

    Tekawy, Jonathan A.; Safonov, Michael G.; Chiang, Richard Y.

    1989-01-01

    Stability margin for multiloop flight control systems has become a critical issue, especially in highly maneuverable aircraft designs where there are inherent strong cross-couplings between the various feedback control loops. To cope with this issue, we have developed computer algorithms based on non-differentiable optimization theory. These algorithms have been developed for computing the Multivariable Stability Margin (MSM). The MSM of a dynamical system is the size of the smallest structured perturbation in component dynamics that will destabilize the system. These algorithms have been coded and appear to be reliable. As illustrated by examples, they provide the basis for evaluating the robustness and performance of flight control systems.

  3. Application of matrix singular value properties for evaluating gain and phase margins of multiloop systems. [stability margins for wing flutter suppression and drone lateral attitude control

    Science.gov (United States)

    Mukhopadhyay, V.; Newsom, J. R.

    1982-01-01

    A stability margin evaluation method in terms of simultaneous gain and phase changes in all loops of a multiloop system is presented. A universal gain-phase margin evaluation diagram is constructed by generalizing an existing method using matrix singular value properties. Using this diagram and computing the minimum singular value of the system return difference matrix over the operating frequency range, regions of guaranteed stability margins can be obtained. Singular values are computed for a wing flutter suppression and a drone lateral attitude control problem. The numerical results indicate that this method predicts quite conservative stability margins. In the second example if the eigenvalue magnitude is used instead of the singular value, as a measure of nearness to singularity, more realistic stability margins are obtained. However, this relaxed measure generally cannot guarantee global stability.

  4. Application of matrix singular value properties for evaluating gain and phase margins of multiloop systems. [stability margins for wing flutter suppression and drone lateral attitude control

    Science.gov (United States)

    Mukhopadhyay, V.; Newsom, J. R.

    1982-01-01

    A stability margin evaluation method in terms of simultaneous gain and phase changes in all loops of a multiloop system is presented. A universal gain-phase margin evaluation diagram is constructed by generalizing an existing method using matrix singular value properties. Using this diagram and computing the minimum singular value of the system return difference matrix over the operating frequency range, regions of guaranteed stability margins can be obtained. Singular values are computed for a wing flutter suppression and a drone lateral attitude control problem. The numerical results indicate that this method predicts quite conservative stability margins. In the second example if the eigenvalue magnitude is used instead of the singular value, as a measure of nearness to singularity, more realistic stability margins are obtained. However, this relaxed measure generally cannot guarantee global stability.

  5. Phase diagram for a nano-yttria-stabilized zirconia system

    DEFF Research Database (Denmark)

    Asadikiya, Mohammad; Sabarou, Hooman; Chen, Ming;

    2016-01-01

    Due to the attractive properties of nanoparticles because of their effective surface area, they have been studied widely. Nano-yttria-stabilized zirconia (n-YSZ) is a ceramic which has been scrutinized extensively in past years. Because of the different stability behavior of n-YSZ in comparison...... with bulk YSZ, a new phase diagram is needed for the n-YSZ system in order to identify stable phases under various conditions. In this study, a phase diagram for the n-YSZ system was provided to determine phase stability ranges at room temperature with respect to particle size and composition....... By applying the CALPHAD approach, a 3-D phase diagram for the n-YSZ system was established in which the stability range of each individual phase can be predicted based on the particle size, composition, and temperature....

  6. Time Domain Stability Margin Assessment Method

    Science.gov (United States)

    Clements, Keith

    2017-01-01

    The baseline stability margins for NASA's Space Launch System (SLS) launch vehicle were generated via the classical approach of linearizing the system equations of motion and determining the gain and phase margins from the resulting frequency domain model. To improve the fidelity of the classical methods, the linear frequency domain approach can be extended by replacing static, memoryless nonlinearities with describing functions. This technique, however, does not address the time varying nature of the dynamics of a launch vehicle in flight. An alternative technique for the evaluation of the stability of the nonlinear launch vehicle dynamics along its trajectory is to incrementally adjust the gain and/or time delay in the time domain simulation until the system exhibits unstable behavior. This technique has the added benefit of providing a direct comparison between the time domain and frequency domain tools in support of simulation validation.

  7. Stability field diagrams for Ln–O–Cl systems

    Indian Academy of Sciences (India)

    K T JACOB; APOORVA DIXIT; ARNEET RAJPUT

    2016-06-01

    Isothermal stability field diagrams for Ln−O−Cl systems (Ln = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb) are developed by taking partial pressures of volatile components oxygen and chlorine as variables. Thermodynamic properties of all the oxides and trichlorides (LnCl$_3$) are available in the literature. However, data for oxychlorides (LnOCl) and dichlorides (LnCl$_2$) are limited. Based on systematic trends in stability of these compounds across the lanthanide series, missing data are estimated to construct the diagrams for 13 Ln−O−Cl systems at 1000 K. All the lanthanide elements form stable LnCl$_3$ and LnOCl. Dichlorides of Nd, Sm, Eu, Dy, Tm and Yb are stable. For systems in which dichlorides are unstable (Ln = La, Ce, Pr, Gd, Tb, Ho, Er), the LnOCl is in equilibrium with the metal (Ln) and the stability field of LnOCl is sandwiched between those of oxides and trichlorides. Stability field diagrams of lanthanide systems forming stable LnCl$_2$ are of two kinds: in the first kind (Ln = Nd,Dy) the stability fields of Ln and LnOCl are in contact and the stability field of LnOCl separates the fields of chlorides and oxides. In diagrams of the second kind (Ln = Sm, Eu, Tm, Yb) there is a direct equilibrium between the oxides and dichlorides at low partial pressures of oxygen and chlorine. There is no contact between the stability fields of Ln and LnOCl; the stability field of LnOCl intervenes between the oxide and chloride phases only at higher partial pressures.

  8. Phase Stability Diagrams for High Temperature Corrosion Processes

    Directory of Open Access Journals (Sweden)

    J. J. Ramos-Hernandez

    2013-01-01

    Full Text Available Corrosion phenomena of metals by fused salts depend on chemical composition of the melt and environmental conditions of the system. Detail knowledge of chemistry and thermodynamic of aggressive species formed during the corrosion process is essential for a better understanding of materials degradation exposed to high temperature. When there is a lack of kinetic data for the corrosion processes, an alternative to understand the thermodynamic behavior of chemical species is to utilize phase stability diagrams. Nowadays, there are several specialized software programs to calculate phase stability diagrams. These programs are based on thermodynamics of chemical reactions. Using a thermodynamic data base allows the calculation of different types of phase diagrams. However, sometimes it is difficult to have access to such data bases. In this work, an alternative way to calculate phase stability diagrams is presented. The work is exemplified in the Na-V-S-O and Al-Na-V-S-O systems. This system was chosen because vanadium salts is one of the more aggressive system for all engineering alloys, especially in those processes where fossil fuels are used.

  9. Marginal Stability Boundaries for Infinite-n Ballooning Modes in a Quasi-axisymmetric Stellarator

    Energy Technology Data Exchange (ETDEWEB)

    S.R. Hudson; C.C. Hegna

    2003-09-15

    A method for computing the ideal-MHD stability boundaries in three-dimensional equilibria is employed. Following Hegna and Nakajima [Phys. Plasmas 5 (May 1998) 1336], a two-dimensional family of equilibria are constructed by perturbing the pressure and rotational-transform profiles in the vicinity of a flux surface for a given stellarator equilibrium. The perturbations are constrained to preserve the magnetohydrodynamic equilibrium condition. For each perturbed equilibrium, the infinite-n ballooning stability is calculated. Marginal stability diagrams are thus constructed that are analogous to (s; a) diagrams for axisymmetric configurations. A quasi-axisymmetric stellarator is considered. Calculations of stability boundaries generally show regions of instability can occur for either sign of the average magnetic shear. Additionally, regions of second-stability are present.

  10. Evidence for Marginal Stability in Emulsions

    Science.gov (United States)

    Lin, Jie; Jorjadze, Ivane; Pontani, Lea-Laetitia; Wyart, Matthieu; Brujic, Jasna

    2016-11-01

    We report the first measurements of the effect of pressure on vibrational modes in emulsions, which serve as a model for soft frictionless spheres at zero temperature. As a function of the applied pressure, we find that the density of states D (ω ) exhibits a low-frequency cutoff ω*, which scales linearly with the number of extra contacts per particle δ z . Moreover, for ω Soft Matter 10, 5628 (2014); S. Franz, G. Parisi, P. Urbani, and F. Zamponi, Proc. Natl. Acad. Sci. U.S.A. 112, 14539 (2015)]. Finally, the degree of localization of the softest low frequency modes increases with compression, as shown by the participation ratio as well as their spatial configurations. Overall, our observations show that emulsions are marginally stable and display non-plane-wave modes up to vanishing frequencies.

  11. Vibrational anomalies and marginal stability of glasses

    KAUST Repository

    Marruzzo, Alessia

    2013-01-01

    The experimentally measured vibrational spectrum of glasses strongly deviates from that expected in Debye\\'s elasticity theory: The density of states deviates from Debye\\'s ω2 law ("boson peak"), the sound velocity shows a negative dispersion in the boson-peak frequency regime, and there is a strong increase in the sound attenuation near the boson-peak frequency. A generalized elasticity theory is presented, based on the model assumption that the shear modulus of the disordered medium fluctuates randomly in space. The fluctuations are assumed to be uncorrelated and have a certain distribution (Gaussian or otherwise). Using field-theoretical techniques one is able to derive mean-field theories for the vibrational spectrum of a disordered system. The theory based on a Gaussian distribution uses a self-consistent Born approximation (SCBA),while the theory for non-Gaussian distributions is based on a coherent-potential approximation (CPA). Both approximate theories appear to be saddle-point approximations of effective replica field theories. The theory gives a satisfactory explanation of the vibrational anomalies in glasses. Excellent agreement of the SCBA theory with simulation data on a soft-sphere glass is reached. Since the SCBA is based on a Gaussian distribution of local shear moduli, including negative values, this theory describes a shear instability as a function of the variance of shear fluctuations. In the vicinity of this instability, a fractal frequency dependence of the density of states and the sound attenuation ∝ ω1+a is predicted with a ≲ 1/2. Such a frequency dependence is indeed observed both in simulations and in experimental data. We argue that the observed frequency dependence stems from marginally stable regions in a glass and discuss these findings in terms of rigidity percolation. © 2013 EDP Sciences and Springer.

  12. Certifiable higher order sliding mode control: Practical stability margins approach

    Science.gov (United States)

    Panathula, Chandrasekhara Bharath

    The Higher Order Sliding Mode (HOSM) controllers are well known for their robustness/insensitivity to bounded perturbations and for handling any given arbitrary relative degree system. The HOSM controller is to be certified for robustness to unmodeled dynamics, before deploying the controller for practical applications. Phase Margin (PM) and Gain Margin ( GM) are the classical characteristics used in linear systems to quantify the linear controller robustness to unmodeled dynamics, and certain values of these margins are required to certify the controller. These conventional margins (PM and GM) are extended to Practical Stability Phase Margin (PSPM) and Practical Stability Gain Margin (PSGM) in this dissertation, and are used to quantify the HOSM control robustness to unmodeled dynamics, presiding the tool to close the gap for HOSM control certification. The proposed robustness metrics ( PSPM and PSGM) are identified by developing tools/algorithms based on Describing Function-Harmonic Balance method. In order for the HOSM controller to achieve the prescribed values on robustness metrics ( PSPM and PSGM), the HOSM controller is cascaded with a linear compensator. A case study of the application of the proposed metrics (PSPM and PSGM) for the certification of F-16 aircraft HOSM attitude control robustness to cascade unmodeled dynamics is presented. In addition, several simulation examples are presented to verify and to validate the proposed methodology.

  13. Using state diagrams for predicting colloidal stability of whey protein beverages.

    Science.gov (United States)

    Wagoner, Ty B; Ward, Loren; Foegeding, E Allen

    2015-05-06

    A method for evaluating aspects of colloidal stability of whey protein beverages after thermal treatment was established. Three state diagrams for beverages (pH 3-7) were developed representing protein solubility, turbidity, and macroscopic state after two ultrahigh-temperature (UHT) treatments. Key transitions of stability in the state diagrams were explored using electrophoresis and chromatography to determine aggregation propensities of β-lactoglobulin, α-lactalbumin, bovine serum albumin, and glycomacropeptide. The state diagrams present an overlapping view of high colloidal stability at pH 3 accompanied by high solubility of individual whey proteins. At pH 5, beverages were characterized by poor solubility, high turbidity, and aggregation/gelation of whey proteins with the exception of glycomacropeptide. Stability increased at pH 6, due to increased solubility of α-lactalbumin. The results indicate that combinations of state diagrams can be used to identify key regions of stability for whey protein containing beverages.

  14. On the dynamics of turbulent transport near marginal stability

    Energy Technology Data Exchange (ETDEWEB)

    Diamond, P.H. [California Univ., San Diego, La Jolla, CA (United States). Dept. of Physics]|[General Atomics, San Diego, CA (United States); Hahm, T.S. [Princeton Univ., NJ (United States). Plasma Physics Lab.

    1995-03-01

    A general methodology for describing the dynamics of transport near marginal stability is formulated. Marginal stability is a special case of the more general phenomenon of self-organized criticality. Simple, one field models of the dynamics of tokamak plasma self-organized criticality have been constructed, and include relevant features such as sheared mean flow and transport bifurcations. In such models, slow mode (i.e. large scale, low frequency transport events) correlation times determine the behavior of transport dynamics near marginal stability. To illustrate this, impulse response scaling exponents (z) and turbulent diffusivities (D) have been calculated for the minimal (Burgers) and sheared flow models. For the minimal model, z = 1 (indicating ballastic propagation) and D {approximately}(S{sub 0}{sup 2}){sup 1/3}, where S{sub 0}{sup 2} is the noise strength. With an identically structured noise spectrum and flow with shearing rate exceeding the ambient decorrelation rate for the largest scale transport events, diffusion is recovered with z = 2 and D {approximately} (S{sub 0}{sup 2}){sup 3/5}. This indicates a qualitative change in the dynamics, as well as a reduction in losses. These results are consistent with recent findings from {rho} scaling scans. Several tokamak transport experiments are suggested.

  15. Operational Modal Analysis Based on Subspace Algorithm with an Improved Stabilization Diagram Method

    Directory of Open Access Journals (Sweden)

    Shiqiang Qin

    2016-01-01

    Full Text Available Subspace-based algorithms for operational modal analysis have been extensively studied in the past decades. In the postprocessing of subspace-based algorithms, the stabilization diagram is often used to determine modal parameters. In this paper, an improved stabilization diagram is proposed for stochastic subspace identification. Specifically, first, a model order selection method based on singular entropy theory is proposed. The singular entropy increment is calculated from nonzero singular values of the output covariance matrix. The corresponding model order can be selected when the variation of singular entropy increment approaches to zero. Then, the stabilization diagram with confidence intervals which is established using the uncertainty of modal parameter is presented. Finally, a simulation example of a four-story structure and a full-scale cable-stayed footbridge application is employed to illustrate the improved stabilization diagram method. The study demonstrates that the model order can be reasonably determined by the proposed method. The stabilization diagram with confidence intervals can effectively remove the spurious modes.

  16. Study on flow stability margin by method of system identification

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Youjie; Jiang Shengyao [Tsinghua Univ., Beijing, BJ (China). Inst. of Nuclear Energy Technology

    1999-11-01

    The main objective of the investigation is to develop a practical technology and method in engineering, based on general control theory, for distinguishing two-phase flow stability and identifying the safety margin by using the system identification method. By combining the two-phase flow stability theory in the thermo-physics field with the system stability theory and the system identification method in the field of information science, a thermo-hydraulic experiment technology with a new concept was developed. The experiment was carried out on the thermo-hydraulic test system HRTL-5 which serves as simulator to the primary circulation of the nuclear heating reactor NHR-5 and was used for investigation on its thermo-physical behavior. Reverse repeat pseudo-random sequences which were added to the steady heat flux as input signal sources and measured flow rates as response function were used in the test. The two-phase flow stability and the stability margin of the natural circulation system were investigated by analyzing the system pulse response function, the decay ratio and the stability boundary under different operational conditions. The results are compared with those obtained by using conventional methods. The test method and typical results obtained are presented in this paper. (orig.) [German] Das Hauptziel der Untersuchung ist die Entwicklung einer Technik und eines Verfahrens um - basierend auf allgemeiner Regelungstheorie - die Stabilitaet einer Zweiphasenstroemung zu bestimmen und unter Verwendung von Methoden zur Systemidentifikation Sicherheitsreserven zu ermitteln. Durch Kombination der Theorie der Zweiphasenstroemungsstabilitaet im Bereich der Thermophysik mit der Systemstabilitaetstheorie und der informationstheoretischen Systemidentifikationsmethode wurde eine thermohydraulische Experimentiertechnik neuartigen Konzepts entwickelt. Die Versuche wurden auf dem Thermohydraulikteststand HRTL-5 ausgefuehrt, der dem Primaeranlauf des Heizreaktors HHR-5

  17. A new transient stability margin based on dynamic security region and its applications

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A new transient stability margin is proposed based on a new expression of dynamic security region (DSR) which is developed from the existing expression of DSR. Applications of the DSR based transient stability margin to contingency ranking and screening are discussed. Simulations in the 10-machine 39-bus New England system are performed to show the effectiveness of the proposed DSR based tran-sient stability margin.

  18. Black Hole Entropy, Marginal Stability and Mirror Symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Aspinwall, Paul S.; Maloney, Alexander; Simons, Aaron

    2006-10-06

    We consider the superconformal quantum mechanics associated to BPS black holes in type IIB Calabi-Yau compactifications. This quantum mechanics describes the dynamics of D-branes in the near-horizon attractor geometry of the black hole. In many cases, the black hole entropy can be found by counting the number of chiral primaries in this quantum mechanics. Both the attractor mechanism and notions of marginal stability play important roles in generating the large number of microstates required to explain this entropy. We compute the microscopic entropy explicitly in a few different cases, where the theory reduces to quantum mechanics on the moduli space of special Lagrangians. Under certain assumptions, the problem may be solved by implementing mirror symmetry as three T-dualities: this is essentially the mirror of a calculation by Gaiotto, Strominger and Yin. In some simple cases, the calculation may be done in greater generality without resorting to conjectures about mirror symmetry. For example, the K3 x T{sub 2} case may be studied precisely using the Fourier-Mukai transform.

  19. A New Criterion for the Stabilization Diagram Used with Stochastic Subspace Identification Methods: An Application to an Aircraft Skeleton

    Directory of Open Access Journals (Sweden)

    E. Mrabet

    2014-01-01

    Full Text Available The modal parameters of a structure that is estimated from ambient vibration measurements are always subject to bias and variance errors. Accordingly the concept of the stabilization diagram is introduced to help users identify the correct model. One of the most important problems using this diagram is the appearance of spurious modes that should be discriminated to simplify modes selections. This study presents a new stabilization criterion obtained through a novel numerical implementation of the stabilization diagram and the discussion of model validation employing the power spectral density. As an application, an aircraft skeleton is used.

  20. Phase stability in nanoscale material systems: extension from bulk phase diagrams.

    Science.gov (United States)

    Bajaj, Saurabh; Haverty, Michael G; Arróyave, Raymundo; Goddard, William A; Shankar, Sadasivan

    2015-06-07

    Phase diagrams of multi-component systems are critical for the development and engineering of material alloys for all technological applications. At nano dimensions, surfaces (and interfaces) play a significant role in changing equilibrium thermodynamics and phase stability. In this work, it is shown that these surfaces at small dimensions affect the relative equilibrium thermodynamics of the different phases. The CALPHAD approach for material surfaces (also termed "nano-CALPHAD") is employed to investigate these changes in three binary systems by calculating their phase diagrams at nano dimensions and comparing them with their bulk counterparts. The surface energy contribution, which is the dominant factor in causing these changes, is evaluated using the spherical particle approximation. It is first validated with the Au-Si system for which experimental data on phase stability of spherical nano-sized particles is available, and then extended to calculate phase diagrams of similarly sized particles of Ge-Si and Al-Cu. Additionally, the surface energies of the associated compounds are calculated using DFT, and integrated into the thermodynamic model of the respective binary systems. In this work we found changes in miscibilities, reaction compositions of about 5 at%, and solubility temperatures ranging from 100-200 K for particles of sizes 5 nm, indicating the importance of phase equilibrium analysis at nano dimensions.

  1. Applied Time Domain Stability Margin Assessment for Nonlinear Time-Varying Systems

    Science.gov (United States)

    Kiefer, J. M.; Johnson, M. D.; Wall, J. H.; Dominguez, A.

    2016-01-01

    The baseline stability margins for NASA's Space Launch System (SLS) launch vehicle were generated via the classical approach of linearizing the system equations of motion and determining the gain and phase margins from the resulting frequency domain model. To improve the fidelity of the classical methods, the linear frequency domain approach can be extended by replacing static, memoryless nonlinearities with describing functions. This technique, however, does not address the time varying nature of the dynamics of a launch vehicle in flight. An alternative technique for the evaluation of the stability of the nonlinear launch vehicle dynamics along its trajectory is to incrementally adjust the gain and/or time delay in the time domain simulation until the system exhibits unstable behavior. This technique has the added benefit of providing a direct comparison between the time domain and frequency domain tools in support of simulation validation. This technique was implemented by using the Stability Aerospace Vehicle Analysis Tool (SAVANT) computer simulation to evaluate the stability of the SLS system with the Adaptive Augmenting Control (AAC) active and inactive along its ascent trajectory. The gains for which the vehicle maintains apparent time-domain stability defines the gain margins, and the time delay similarly defines the phase margin. This method of extracting the control stability margins from the time-domain simulation is relatively straightforward and the resultant margins can be compared to the linearized system results. The sections herein describe the techniques employed to extract the time-domain margins, compare the results between these nonlinear and the linear methods, and provide explanations for observed discrepancies. The SLS ascent trajectory was simulated with SAVANT and the classical linear stability margins were evaluated at one second intervals. The linear analysis was performed with the AAC algorithm disabled to attain baseline stability

  2. Stability Diagrams of a Bose-Einstein Condensate in a Periodic Array of Quantum Wells

    Institute of Scientific and Technical Information of China (English)

    XUE Rui; LIANG Zhao-Xin; LI Wei-Dong

    2009-01-01

    With the help of a set of exact closed-form solutions to the stationary Gross-Pitaevskii equation, we compre-hensively investigate Landau and dynamical instabilities of a Bose-Einstein condensate in a periodic array of quantum wells. In the tight-binding limit, the analytical expressions for both Landau and dynamical instabilities are obtained in terms of the compressibility and effective mass of the BEC system. Then the stability phase diagrams are shown to be similar to the one in the case of the sinusoidal optical lattice.

  3. Dynamic stability margin using a marker based system and Tekscan: a comparison of four gait conditions.

    Science.gov (United States)

    Lugade, Vipul; Kaufman, Kenton

    2014-01-01

    Stability during gait is maintained through control of the center of mass (CoM) position and velocity in relation to the base of support (BoS). The dynamic stability margin, or the interaction of the extrapolated center of mass with the closest boundary of the BoS, can reveal possible control errors during gait. The purpose of this study was to investigate a marker based method for defining the BoS, and compare the dynamic stability margin throughout gait in comparison to a BoS defined from foot pressure sensors. The root mean squared difference between these two methodologies ranged from 0.9 cm to 3.5 cm, when walking under four conditions: plantigrade, equinus, everted, and inverted. As the stability margin approaches -35 cm prior to contralateral heel strike, there was approximately 90% agreement between the two systems at this time point. Underestimation of the marker based dynamic stability margin or overestimation of the pressure based dynamic stability margin was due to inaccuracies in defining the medial boundary of the BoS. Overall, care must be taken to ensure similar definitions of the BoS are utilized when comparing the dynamic stability margin between participants and gait conditions.

  4. The intertemporal stability of the concentration-margins relationship in Dutch and U.S. manufacturing

    NARCIS (Netherlands)

    Y.M. Prince (Yvonne); A.R. Thurik (Roy)

    1994-01-01

    textabstractFactors influencing price-cost margins are investigated using a rich panel data base of the Dutch manufacturing sector. Attention is devoted to the intertemporal stability of the relationship explaining price-cost margins and to a comparison with U.S. results. Our results indicate that i

  5. A note on degeneracy, marginal stability and extremality of black hole horizons

    CERN Document Server

    Jaramillo, José Luis

    2012-01-01

    Given a stationary axisymmetric black hole horizon admitting a section characterized as a future stable marginally outer trapped surface, we extend the equivalence between the notions of horizon degeneracy and marginal stability to the fulfillment, under the dominant energy condition, of the A=8\\pi |J| geometric relation.

  6. The intertemporal stability of the concentration-margins relationship in Dutch and U.S. manufacturing

    NARCIS (Netherlands)

    Y.M. Prince (Yvonne); A.R. Thurik (Roy)

    1994-01-01

    textabstractFactors influencing price-cost margins are investigated using a rich panel data base of the Dutch manufacturing sector. Attention is devoted to the intertemporal stability of the relationship explaining price-cost margins and to a comparison with U.S. results. Our results indicate that

  7. A multiloop generalization of the circle criterion for stability margin analysis

    Science.gov (United States)

    Safonov, M. G.; Athans, M.

    1981-01-01

    In order to provide a theoretical tool well suited for use in characterizing the stability margins (e.g., gain and phase margins) of multiloop feedback systems, multiloop input-output stability results generalizing the circle stability criterion are considered. Generalized conic sectors with 'centers' and 'radii' determined by linear dynamical operators are employed to enable an engineer to specify the stability margins which he desires as a frequency-dependent convex set of modeling errors (including nonlinearities, gain variations, and phase variations) which the system must be able to tolerate in each feedback loop without instability. The resulting stability criterion gives sufficient conditions for closed-loop stability in the presence of such frequency-dependent modeling errors, even when the modeling errors occur simultaneously in all loops.

  8. Estimation method of margin gasdynamic stability of the gas turbine engine while in service

    Directory of Open Access Journals (Sweden)

    І.Ф. Кінащук

    2005-01-01

    Full Text Available  Considered is the method of an estimation gasdynamic stability margin of the compressor gas turbine engine under operating conditions. The given way can be used at diagnosing gas turbine engine and gas turbine engine installations.

  9. Replicon modes and fixed-point marginal stability for systems with extended impurities

    Science.gov (United States)

    de Cesare, Luigi; Mercaldo, Maria Teresa

    1999-08-01

    The fixed-point marginal stability, found for systems with extended quenched impurities within a one-step replica symmetry breaking (RSB) renormalization-group treatment, is further explored in terms of replicon eigenvalues, recently introduced as a simple way to investigate the fixed-point stability properties with respect to the continuous RSB modes. We find that the marginal stability occurs again when these modes are taken into account, in contrast with the short-range correlated impurity case where the continuous RSB fluctuations drastically change the one-step RSB fixed-point stability scenario.

  10. Computation of Stability Delay Margin of Time-Delayed Generator Excitation Control System with a Stabilizing Transformer

    Directory of Open Access Journals (Sweden)

    Saffet Ayasun

    2014-01-01

    Full Text Available This paper investigates the effect of time delays on the stability of a generator excitation control system compensated with a stabilizing transformer known as rate feedback stabilizer to damp out oscillations. The time delays are due to the use of measurement devices and communication links for data transfer. An analytical method is presented to compute the delay margin for stability. The delay margin is the maximum amount of time delay that the system can tolerate before it becomes unstable. First, without using any approximation, the transcendental characteristic equation is converted into a polynomial without the transcendentality such that its real roots coincide with the imaginary roots of the characteristic equation exactly. The resulting polynomial also enables us to easily determine the delay dependency of the system stability and the sensitivities of crossing roots with respect to the time delay. Then, an expression in terms of system parameters and imaginary root of the characteristic equation is derived for computing the delay margin. Theoretical delay margins are computed for a wide range of controller gains and their accuracy is verified by performing simulation studies. Results indicate that the addition of a stabilizing transformer to the excitation system increases the delay margin and improves the system damping significantly.

  11. New online voltage stability margins and risk assessment for multi-bus smart power grids

    Science.gov (United States)

    Aldeen, M.; Saha, S.; Alpcan, T.; Evans, R. J.

    2015-07-01

    This paper presents a quantitative framework for assessment of voltage stability in smart power networks. First, new stability indices similar to gain and phase margins in linear time invariant control systems are introduced. These indices can be computed online in conjunction with load-flow calculations. Then, a novel risk assessment framework incorporating the new stability indices is developed to methodologically quantify the voltage stability risks a power system faces at any given operating condition. In contrast to existing local stability indices and qualitative risk approaches, the indices and framework introduced provide analytical and quantitative evaluation of voltage stability and associated risks. The results are illustrated with a numerical example.

  12. A general program to compute the multivariable stability margin for systems with parametric uncertainty

    Science.gov (United States)

    Sanchez Pena, Ricardo S.; Sideris, Athanasios

    1988-01-01

    A computer program implementing an algorithm for computing the multivariable stability margin to check the robust stability of feedback systems with real parametric uncertainty is proposed. The authors present in some detail important aspects of the program. An example is presented using lateral directional control system.

  13. Investigation of phase diagrams and physical stability of drug-polymer solid dispersions.

    Science.gov (United States)

    Lu, Jiannan; Shah, Sejal; Jo, Seongbong; Majumdar, Soumyajit; Gryczke, Andreas; Kolter, Karl; Langley, Nigel; Repka, Michael A

    2015-01-01

    Solid dispersion technology has been widely explored to improve the solubility and bioavailability of poorly water-soluble compounds. One of the critical drawbacks associated with this technology is the lack of physical stability, i.e. the solid dispersion would undergo recrystallization or phase separation thus limiting a product's shelf life. In the current study, the melting point depression method was utilized to construct a complete phase diagram for felodipine (FEL)-Soluplus® (SOL) and ketoconazole (KTZ)-Soluplus® (SOL) binary systems, respectively, based on the Flory-Huggins theory. The miscibility or solubility of the two compounds in SOL was also determined. The Flory-Huggins interaction parameter χ values of both systems were calculated as positive at room temperature (25 °C), indicating either compound was miscible with SOL. In addition, the glass transition temperatures of both solid dispersion systems were theoretically predicted using three empirical equations and compared with the practical values. Furthermore, the FEL-SOL solid dispersions were subjected to accelerated stability studies for up to 3 months.

  14. High temperature corrosion in chloridizing atmospheres: development of material quasi-stability diagrams and coatings

    Energy Technology Data Exchange (ETDEWEB)

    Doublet, S.; Schuetze, M. [Karl-Winnacker-Institut der DECHEMA e.V., Theodor-Heuss-Allee 25, D-60486 Frankfurt am Main (Germany)

    2004-07-01

    Chlorine gas is widely encountered in chemical industries, e. g. in waste incinerators and plastic/polymer decomposition mills. The presence of chlorine may significantly reduce the life-time of the components. Although metallic materials have been widely used under such conditions there is still a need for data on the role of the different alloying elements in commercial alloys. The purpose of this work is to produce a clear picture of which alloying elements play a detrimental role and which elements are beneficial. These results can be used as a tool for general assessment of metallic alloys with regard to their performance in chloridizing high temperature environments. A previous study has already been performed in oxidizing-chloridizing atmospheres and led to the elaboration of material quasi-stability diagrams. As a follow-up the present work has been performed in reducing-chloridizing atmospheres in order to validate these diagrams at low partial pressures of oxygen. The behaviour of 9 commercial materials where the content of the major alloying elements was varied in a systematic manner was investigated in reducing-chloridizing atmospheres (in Ar containing up to 2 vol.% Cl{sub 2} and down to 1 ppm O{sub 2}) at 800 deg. C. As the thermodynamical approach to corrosion in such atmospheres could not explain all the phenomena which occur, kinetics calculations i.e. diffusion calculations were carried out. Pack cementation and High Velocity Oxy-Fuel (HVOF) coatings were also developed from the best alloying elements previously found by the calculations and the corrosion experiments. Corrosion tests on the coated materials were then performed in the same conditions as the commercial alloys. (authors)

  15. Stabilizing the hexagonal close packed structure of hard spheres with polymers: Phase diagram, structure, and dynamics

    Science.gov (United States)

    Edison, John R.; Dasgupta, Tonnishtha; Dijkstra, Marjolein

    2016-08-01

    We study the phase behaviour of a binary mixture of colloidal hard spheres and freely jointed chains of beads using Monte Carlo simulations. Recently Panagiotopoulos and co-workers predicted [Nat. Commun. 5, 4472 (2014)] that the hexagonal close packed (HCP) structure of hard spheres can be stabilized in such a mixture due to the interplay between polymer and the void structure in the crystal phase. Their predictions were based on estimates of the free-energy penalty for adding a single hard polymer chain in the HCP and the competing face centered cubic (FCC) phase. Here we calculate the phase diagram using free-energy calculations of the full binary mixture and find a broad fluid-solid coexistence region and a metastable gas-liquid coexistence region. For the colloid-monomer size ratio considered in this work, we find that the HCP phase is only stable in a small window at relatively high polymer reservoir packing fractions, where the coexisting HCP phase is nearly close packed. Additionally we investigate the structure and dynamic behaviour of these mixtures.

  16. Phase Stability, Kinetic Diagrams and Diffusion Path in High Temperature Oxidation of Binary Solid-Solution Alloys

    Institute of Scientific and Technical Information of China (English)

    Yan NIU; F. Gesmundo

    2003-01-01

    The phase diagrams of ternary systems involving two metal components and one oxidant are considered first, the limitations to their use is discussed in relation to the high temperature oxidation of binary alloys. Kinetic diagrams,which are useful to predict the conditions for the stability of the two mutually insoluble oxides as the external scale, are then calculated on the basis of thermodynamic and kinetic data concerning both the alloys and the oxides, assuming the validity of the parabolic rate law. A combination of the two types of diagrams provides a more detail information about the oxidation behavior of binary alloys. The calculation of the diffusion paths, which relate the oxidant pressure to the composition of the system in terms of the alloy components both in the alloy and in the scale during an initial stage of the reaction in the presence of the parabolic rate law, is finally developed.

  17. Geometric thermal phase diagrams for studying the thermal dynamic stability of hollow gold nanoballs at different temperatures.

    Science.gov (United States)

    Jiang, Luyun; Sun, Wei; Gao, Yajun; Zhao, Jianwei

    2014-04-14

    Thermal stability is one of the main concerns for the synthesis of hollow nanoparticles. In this work, molecular dynamics simulation gave an insight into the atomic reconstruction and energy evolution during the collapse of hollow gold nanoballs, based on which a mechanism was proposed. The stability was found to depend on temperature, its wall thickness and aspect ratio to a great extent. The relationship among these three factors was revealed in geometric thermal phase diagrams (GTPDs). The GTPDs were studied theoretically, and the boundary between different stability regions can be fitted and calculated. Therefore, the GTPDs at different temperatures can be deduced and used as a guide for hollow structure synthesis.

  18. Stability Diagrams of Triple-Dot Single-Electron Device with Single Common Gate

    Science.gov (United States)

    Imai, Shigeru

    2011-03-01

    Triple-dot single-electron devices with a single common gate have been studied. The overall stability diagram of the single-electron device with a homogeneous tunnel capacitance Cj and a homogeneous gate capacitance Cg is derived algebraically. If the set of excess electron numbers in the three islands (n1, n2, n3) is (n, n, n), (n, n + 1, n), or (n, n - 1, n), where n is an arbitrary integer, the corresponding stability region S(n1, n2, n3) exists for any Cg/Cj. S(n, n, n), S(n, n + 1, n), and S(n, n - 1, n) for all n are arranged along the Vg axis in the order of n1 + n2 + n3, where Vg is gate voltage, and neighboring stability regions overlap for any Cg/Cj ratio. Overlaps between S(n, n, n) and S(n, n ±1, n) for all n have identical kite-like shapes. Overlaps between S(n, n + 1, n) and S(n + 1, n, n + 1) for all n have identical rhombus shapes. Turnstile operations are possible by alternating gate voltage around overlaps between S(n, n, n) and S(n, n ±1, n) and around overlaps between S(n, n + 1, n) and S(n + 1, n, n + 1), though the sequences of single-electron transfers are different. The range of drain voltage and the swing of gate voltage for turnstile operation are estimated. The overlap between S(n, n + 1, n) and S(n + 1, n, n + 1) seems superior to the overlap between S(n, n, n) and S(n, n ±1, n) because of the larger ratio of the drain voltage range to the gate voltage swing, though the overlap between S(n, n + 1, n) and S(n + 1, n, n + 1) might require higher reliability against the nonuniformity of gate capacitances.

  19. Stability Diagrams of Single-Common-Gate Double-Dot Single-Electron Transistors with Arbitrary Junction and Gate Capacitances

    Science.gov (United States)

    Imai, Shigeru; Kato, Hiroki; Hiraoka, Yasuhiro

    2012-12-01

    Stability diagrams of single-common-gate double-dot single-electron transistors are drawn in the Vg-V plane using the exact formulas that represent Coulomb blockade conditions, where the gate, source, and drain voltages are Vg, -V/2, and V/2, respectively. The stability regions are arranged along the Vg axis with no overlap. If gate capacitances Cg1 and Cg2 satisfy Cg1/m1 = Cg2/m2 = C0, the stability diagram is periodic with the period of e/C0 along the Vg axis, where m1 and m2 are natural numbers prime to each other. The stability diagram is point-symmetrical with respect to the point (me/2C0, 0) for all integers m. If Vg increases at V = 0, electrons are transferred into the islands under a rule, which can be explained in terms of periodicity and symmetry. The detailed features are described for the cases of uniform gate capacitances and uniform junction capacitances.

  20. Real-Time Stability Margin Measurements for X-38 Robustness Analysis

    Science.gov (United States)

    Bosworth, John T.; Stachowiak, Susan J.

    2005-01-01

    A method has been developed for real-time stability margin measurement calculations. The method relies on a tailored-forced excitation targeted to a specific frequency range. Computation of the frequency response is matched to the specific frequencies contained in the excitation. A recursive Fourier transformation is used to make the method compatible with real-time calculation. The method was incorporated into the X-38 nonlinear simulation and applied to an X-38 robustness test. X-38 stability margins were calculated for different variations in aerodynamic and mass properties over the vehicle flight trajectory. The new method showed results comparable to more traditional stability analysis techniques, and at the same time, this new method provided coverage that is more complete and increased efficiency.

  1. A Synchrophasor Based Optimal Voltage Control Scheme with Successive Voltage Stability Margin Improvement

    Directory of Open Access Journals (Sweden)

    Heng-Yi Su

    2016-01-01

    Full Text Available This paper proposes an optimal control scheme based on a synchronized phasor (synchrophasor for power system secondary voltage control. The framework covers voltage stability monitoring and control. Specifically, a voltage stability margin estimation algorithm is developed and built in the newly designed adaptive secondary voltage control (ASVC method to achieve more reliable and efficient voltage regulation in power systems. This new approach is applied to improve voltage profile across the entire power grid by an optimized plan for VAR (reactive power sources allocation; therefore, voltage stability margin of a power system can be increased to reduce the risk of voltage collapse. An extensive simulation study on the IEEE 30-bus test system is carried out to demonstrate the feasibility and effectiveness of the proposed scheme.

  2. Structures, electronic properties and stability phase diagrams for copper(I/II) bromide surfaces.

    Science.gov (United States)

    Altarawneh, Mohammednoor; Marashdeh, Ali; Dlugogorski, Bogdan Z

    2015-04-14

    This study presents a comprehensive periodic slab DFT investigation into structures, electronic properties and thermodynamic stability of all plausible terminations of CuBr and CuBr2 surfaces. We first estimate lattice constants, formation and cohesive energies for the two bulk copper bromides before proceeding to analyse geometrical and electronic features of CuBr and CuBr2 configurations. Surface geometries exhibit, to a large extent, corresponding bulk structures. Nevertheless, certain CuBr2 surfaces experience a downward displacement of the topmost Cu-containing layers. We plot total and projected density of states for bulk and surface geometries of these two copper bromides and calculate their associated Bader's electronic charges. Electronic structure analysis for the bulk and surfaces of these two copper bromides show that CuBr bulk and its most stable surface (CuBr(001)_Br) do not exhibit any metallic character, whereas CuBr2 bulk and its most stable surface (CuBr2(001)_Br) both exhibit metallic characters. The formalism of the ab initio atomistic thermodynamics affords the construction of energy phase diagrams. We predict that the CuBr(001) surface, truncated with Br atoms, is the most stable structure among the considered CuBr slabs at all physically meaningful ranges of the chemical potential of bromine. This surface resembles a c(2 × 2)-bromine sheet that was characterised experimentally from initial interaction of Br2 with a Cu(100) surface. We find that surfaces terminated with the electronegative bromine atoms, if accompanied by significant relaxation, tend to be more stable. Calculated surface energies predict the shapes of CuBr and CuBr2 nanoparticles as the chemical potential of bromine changes.

  3. An Improved Force-Angle Stability Margin for Radial Symmetrical Hexapod Robot Subject to Dynamic Effects

    Directory of Open Access Journals (Sweden)

    Shidong Long

    2015-05-01

    Full Text Available This paper presents a study on stability monitoring for a radial symmetrical hexapod robot under dynamic conditions. The force-angle stability margin (FASM measure method has been chosen as the stability criterion. This is because it is suitable for the stability analysis, in terms of external forces or manipulator loads acting on the body. Considering that a radial symmetrical hexapod robot can tumble along the contact point besides tip-over axis, this paper proposes an improved FASM measure method. Furthermore, it provides the method for calculating the stability angle of contact point and simplifies the algorithm of FASM. To verify the improved FASM measure method, three potential dynamic situations have been simulated. The simulation results confirm that, under dynamic conditions, the improved FASM is efficient, simple in terms of calculation cost and sensitive to manipulator loads and external disturbances. This means it has practical value in on-line controllers.

  4. Gas Hydrate Stability and Sampling: The Future as Related to the Phase Diagram

    Directory of Open Access Journals (Sweden)

    E. Dendy Sloan

    2010-12-01

    Full Text Available The phase diagram for methane + water is explained, in relation to hydrate applications, such as in flow assurance and in nature. For natural applications, the phase diagram determines the regions for hydrate formation for two- and three-phase conditions. Impacts are presented for sample preparation and recovery. We discuss an international study for “Round Robin” hydrate sample preparation protocols and testing.

  5. A Sufficient Condition for Power Flow Insolvability with Applications to Voltage Stability Margins

    CERN Document Server

    Molzahn, Daniel K; DeMarco, Christopher L

    2012-01-01

    For the nonlinear power flow problem specified with standard PQ, PV, and slack bus equality constraints, we present a sufficient condition under which the specified set of nonlinear algebraic equations has no solution. This sufficient condition is constructed in a framework of an associated feasible, convex optimization problem. The objective employed in this optimization problem yields a measure of distance (in a parameter set) to the power flow solution boundary. In practical terms, this distance is closely related to quantities that previous authors have proposed as voltage stability margins. A typical margin is expressed in terms of the parameters of system loading (injected powers); here we additionally introduce a new margin in terms of the parameters of regulated bus voltages.

  6. Exploring the conformational space of chromatin fibers and their stability by numerical dynamic phase diagrams.

    Science.gov (United States)

    Stehr, René; Schöpflin, Robert; Ettig, Ramona; Kepper, Nick; Rippe, Karsten; Wedemann, Gero

    2010-03-17

    The three-dimensional structure of chromatin affects DNA accessibility and is therefore a key regulator of gene expression. However, the path of the DNA between consecutive nucleosomes, and the resulting chromatin fiber organization remain controversial. The conformational space available for the folding of the nucleosome chain has been analytically described by phase diagrams with a two-angle model, which describes the chain trajectory by a DNA entry-exit angle at the nucleosome and a torsion angle between consecutive nucleosomes. Here, a novel type of numerical phase diagrams is introduced that relates the geometric phase space to the energy associated with a given chromatin conformation. The resulting phase diagrams revealed differences in the energy landscape that reflect the probability of a given conformation to form in thermal equilibrium. Furthermore, we investigated the effects of entropy and additional degrees of freedom in the dynamic phase diagrams by performing Monte Carlo simulations of the initial chain trajectories. Using our approach, we were able to demonstrate that conformations that initially were geometrically impossible could evolve into energetically favorable states in thermal equilibrium due to DNA bending and torsion. In addition, dynamic phase diagrams were applied to identify chromatin fibers that reflect certain experimentally determined features.

  7. Assessment of marginal stability and permeability of an interim restorative endodontic material.

    Science.gov (United States)

    Kazemi, R B; Safavi, K E; Spångberg, L S

    1994-12-01

    The purpose of this study was to assess the marginal stability and permeability of a new interim restorative endodontic material, Tempit (Centrix Inc., Milford, Conn.), and to compare the findings with the results of two commonly used restorative endodontic materials, Cavit (Premier Dental Products Co., Philadelphia, Pa.) and IRM (Intermediate Restorative Material Capsules, The Caulk Co., Division of Dentsply International Inc., Milford, Del.) This study was performed in several steps. First, the endodontic access cavities were prepared and restored on 80 extracted mandibular molars. The samples were exposed to methylene blue dye solution for 6 days, thermocycled, and sectioned; the dye penetration and diffusion were measured along the margins and into the body of the materials. The second experiment was a special study performed in standardized glass tubes to better evaluate the marginal and body dye penetration into the materials by increasing the length of the fillings. To eliminate the possibility of hygroscopic setting mechanisms of materials, samples were first allowed to set under water before dye was introduced. Cavit and Tempit showed a substantial amount of dye diffusion into the body of the materials. Cavit exhibited the best sealing ability at all times. The marginal and body dye penetration were significantly different for the Tempit material in all experiments than Cavit (p IRM demonstrated the least body penetration of all three materials (p material (p = 0.6 and p = 0.1).(ABSTRACT TRUNCATED AT 250 WORDS)

  8. Computational analysis of a stability robustness margin for structured real-parameter perturbations

    Science.gov (United States)

    Wedell, Evan; Chuang, C.-H.; Wie, Bong

    1989-01-01

    An efficient computational method is presented for stability robustness analysis with structured real-parameter perturbations. A generic model of a class of uncertain dynamical systems is used as an example. The parameter uncertainty is characterized by a real scalar, epsilon. Multilinearity of the closed-loop characteristic polynomial is exploited to permit application of the mapping theorem to calculate the stability robustness margin. It is found that sensitive geometry of the stability boundary in the epsilon, omega-plane renders problematic the calculation of the minimum epsilon as a function of omega. This difficulty is avoided by calculating the minimum distance to the image of the uncertainty domain over omega as a function of epsilon. It is also shown that a certain class of uncertain dynamical systems has the required multilinearity property and are thus amenable to the proposed technique.

  9. An Efficient Approach for Fast and Accurate Voltage Stability Margin Computation in Large Power Grids

    Directory of Open Access Journals (Sweden)

    Heng-Yi Su

    2016-11-01

    Full Text Available This paper proposes an efficient approach for the computation of voltage stability margin (VSM in a large-scale power grid. The objective is to accurately and rapidly determine the load power margin which corresponds to voltage collapse phenomena. The proposed approach is based on the impedance match-based technique and the model-based technique. It combines the Thevenin equivalent (TE network method with cubic spline extrapolation technique and the continuation technique to achieve fast and accurate VSM computation for a bulk power grid. Moreover, the generator Q limits are taken into account for practical applications. Extensive case studies carried out on Institute of Electrical and Electronics Engineers (IEEE benchmark systems and the Taiwan Power Company (Taipower, Taipei, Taiwan system are used to demonstrate the effectiveness of the proposed approach.

  10. Stability margin of linear systems with parameters described by fuzzy numbers.

    Science.gov (United States)

    Husek, Petr

    2011-10-01

    This paper deals with the linear systems with uncertain parameters described by fuzzy numbers. The problem of determining the stability margin of those systems with linear affine dependence of the coefficients of a characteristic polynomial on system parameters is studied. Fuzzy numbers describing the system parameters are allowed to be characterized by arbitrary nonsymmetric membership functions. An elegant solution, graphical in nature, based on generalization of the Tsypkin-Polyak plot is presented. The advantage of the presented approach over the classical robust concept is demonstrated on a control of the Fiat Dedra engine model and a control of the quarter car suspension model.

  11. Regional variability of slope stability: Application to the Eel margin, California

    Science.gov (United States)

    Lee, H.; Locat, J.; Dartnell, P.; Israel, K.; Florence, Wong

    1999-01-01

    Relative values of downslope driving forces and sediment resisting forces determine the locations of submarine slope failures. Both of these vary regionally, and their impact can be addressed when the data are organized in a Geographic Information System (GIS). The study area on the continental margin near the Eel River provides an excellent opportunity to apply GIS spatial analysis techniques for evaluation of slope stability. In this area, swath bathymetric mapping shows seafloor morphology and distribution of slope steepness in fine detail, and sediment analysis of over 70 box cores delineates the variability of sediment density near the seafloor surface. Based on the results of ten geotechnical studies of submarine study areas, we developed an algorithm that relates surface sediment density to the shear strength appropriate to the type of cyclic loading produced by an earthquake. Strength and stress normalization procedures provide results that are conceptually independent of subbottom depth. Results at depth are rigorously applicable if sediment lithology does not vary significantly and consolidation state can be estimated. Otherwise, the method applies only to shallow-seated slope failure. Regional density, slope, and level of anticipated seismic shaking information were combined in a GIS framework to yield a map that illustrates the relative stability of slopes in the face of seismically induced failure. When a measure of predicted relative slope stability is draped on an oblique view of swath bathymetry, a variation in this slope stability is observed on an otherwise smooth slope along the mid-slope region north of a plunging anticline. The section of slope containing diffuse, pockmarked gullies has a lower measure of stability than a separate section containing gullies that have sharper boundaries and somewhat steeper sides. Such an association suggests that our slope-stability analysis relates to the stability of the gully sides. The remainder of the

  12. Assessment of Global Voltage Stability Margin through Radial Basis Function Neural Network

    Directory of Open Access Journals (Sweden)

    Akash Saxena

    2016-01-01

    Full Text Available Dynamic operating conditions along with contingencies often present formidable challenges to the power engineers. Decisions pertaining to the control strategies taken by the system operators at energy management centre are based on the information about the system’s behavior. The application of ANN as a tool for voltage stability assessment is empirical because of its ability to do parallel data processing with high accuracy, fast response, and capability to model dynamic, nonlinear, and noisy data. This paper presents an effective methodology based on Radial Basis Function Neural Network (RBFN to predict Global Voltage Stability Margin (GVSM, for any unseen loading condition of the system. GVSM is used to assess the overall voltage stability status of the power system. A comparative analysis of different topologies of ANN, namely, Feedforward Backprop (FFBP, Cascade Forward Backprop (CFB, Generalized Regression (GR, Layer Recurrent (LR, Nonlinear Autoregressive Exogenous (NARX, ELMAN Backprop, and Feedforward Distributed Time Delay Network (FFDTDN, is carried out on the basis of capability of the prediction of GVSM. The efficacy of RBFN is better than other networks, which is validated by taking the predictions of GVSM at different levels of Additive White Gaussian Noise (AWGN in input features. The results obtained from ANNs are validated through the offline Newton Raphson (N-R method. The proposed methodology is tested over IEEE 14-bus, IEEE 30-bus, and IEEE 118-bus test systems.

  13. New results on the robust stability of PID controllers with gain and phase margins for UFOPTD processes.

    Science.gov (United States)

    Jin, Q B; Liu, Q; Huang, B

    2016-03-01

    This paper considers the problem of determining all the robust PID (proportional-integral-derivative) controllers in terms of the gain and phase margins (GPM) for open-loop unstable first order plus time delay (UFOPTD) processes. It is the first time that the feasible ranges of the GPM specifications provided by a PID controller are given for UFOPTD processes. A gain and phase margin tester is used to modify the original model, and the ranges of the margin specifications are derived such that the modified model can be stabilized by a stabilizing PID controller based on Hermite-Biehlers Theorem. Furthermore, we obtain all the controllers satisfying a given margin specification. Simulation studies show how to use the results to design a robust PID controller.

  14. Calculated Pourbaix Diagrams of Cubic Perovskites for Water Splitting: Stability Against Corrosion

    DEFF Research Database (Denmark)

    Castelli, Ivano Eligio; Thygesen, Kristian Sommer; Jacobsen, Karsten Wedel

    2014-01-01

    We use density functional theory calculations to investigate the stability of cubic perovskites for photo-electrochemical water splitting taking both materials in their bulk crystal structure and dissolved phases into account. The method is validated through a detailed comparison of the calculated...

  15. Stability diagram of unilateral buckling patterns of strip-delaminated films.

    Science.gov (United States)

    Parry, G; Cimetière, A; Coupeau, C; Colin, J; Grilhé, J

    2006-12-01

    Thin films deposited on substrates are usually submitted to large residual compression stresses, causing delamination and buckling of the film into various patterns. The present study is focused on the different equilibria arising on strip-shaped delaminated areas. The three most common types of buckling patterns observed on such strips are known as the straight-sided wrinkles, bubble pattern, and telephone cord blisters. The stability of those equilibria as a function of the two stress components of the loading is investigated. The Föppl-Von Karman model for elastic plates is used for theoretical aspects. The post-critical equilibrium paths of the buckling patterns are investigated numerically by means of the finite-element method. The substrate is assumed to be rigid and the contact to be frictionless. The equilibrium solutions can be classified into families of homologous equilibria allowing the identification of dimensionless parameters for the study of stability. A mapping of the different stable post-critical equilibria is given. It is shown that the straight-sided wrinkles and the bubbles are associated with anisotropy of stresses and/or of elastic properties, whereas the telephone cords are stable at high isotropic stresses. The morphological transitions are experimentally evidenced by in situ atomic force microscopy observations of a nickel 50-nm-thick film under stress.

  16. Urea-induced denaturation of apolipoprotein serum amyloid A reveals marginal stability of hexamer

    Science.gov (United States)

    Wang, Limin; Colón, Wilfredo

    2005-01-01

    Serum Amyloid A (SAA) is an acute phase reactant protein that is predominantly found bound to high-density lipoprotein in plasma. Upon inflammation, the plasma concentration of SAA can increase dramatically, occasionally leading to the development of amyloid A (AA) amyloidosis, which involves the deposition of SAA amyloid fibrils in major organs. We previously found that the murine isoform SAA2.2 exists in aqueous solution as a hexamer containing a central channel. Here we show using various biophysical and biochemical techniques that the SAA2.2 hexamer can be totally dissociated into monomer by ~2 M urea, with the concerted loss of its α-helical structure. However, limited trypsin proteolysis experiments in urea showed a conserved digestion profile, suggesting the preservation of major backbone topological features in the urea-denatured state of SAA2.2. The marginal stability of hexameric SAA2.2 and the presence of residual structure in the denatured monomeric protein suggest that both forms may interconvert in vivo to exert different functions to meet the various needs during normal physiological conditions and in response to inflammatory stimuli. PMID:15937280

  17. Stability Margin Scaling Laws for Distributed Formation Control as a Function of Network Structure

    CERN Document Server

    Hao, He; Mehta, Prashant G

    2010-01-01

    We consider the problem of distributed formation control of a large number of vehicles. An individual vehicle in the formation is assumed to be a fully actuated point mass. A distributed control law is examined: the control action on an individual vehicle depends on (i) its own velocity and (ii) the relative position measurements with a small subset of vehicles (neighbors) in the formation. The neighbors are defined according to an information graph. In this paper we describe a methodology for modeling, analysis, and distributed control design of such vehicular formations whose information graph is a D-dimensional lattice. The modeling relies on an approximation based on a partial differential equation (PDE) that describes the spatio-temporal evolution of position errors in the formation. The analysis and control design is based on the PDE model. We deduce asymptotic formulae for the closed-loop stability margin (absolute value of the real part of the least stable eigenvalue) of the controlled formation. The ...

  18. Time Domain Stability Margin Assessment of the NASA Space Launch System GN&C Design for Exploration Mission One

    Science.gov (United States)

    Clements, Keith; Wall, John

    2017-01-01

    The baseline stability margins for NASA's Space Launch System (SLS) launch vehicle were generated via the classical approach of linearizing the system equations of motion and determining the gain and phase margins from the resulting frequency domain model. To improve the fidelity of the classical methods, the linear frequency domain approach can be extended by replacing static, memoryless nonlinearities with describing functions. This technique, however, does not address the time varying nature of the dynamics of a launch vehicle in flight. An alternative technique for the evaluation of the stability of the nonlinear launch vehicle dynamics along its trajectory is to incrementally adjust the gain and/or time delay in the time domain simulation until the system exhibits unstable behavior. This technique has the added benefit of providing a direct comparison between the time domain and frequency domain tools in support of simulation validation.

  19. Time Domain Stability Margin Assessment of the NS Space Launch System GN&C Design for Exploration Mission One

    Science.gov (United States)

    Clements, Keith; Wall, John

    2017-01-01

    The baseline stability margins for NASA's Space Launch System (SLS) launch vehicle were generated via the classical approach of linearizing the system equations of motion and determining the gain and phase margins from the resulting frequency domain model. To improve the fidelity of the classical methods, the linear frequency domain approach can be extended by replacing static, memoryless nonlinearities with describing functions. This technique, however, does not address the time varying nature of the dynamics of a launch vehicle in flight. An alternative technique for the evaluation of the stability of the nonlinear launch vehicle dynamics along its trajectory is to incrementally adjust the gain and/or time delay in the time domain simulation until the system exhibits unstable behavior. This technique has the added benefit of providing a direct comparison between the time domain and frequency domain tools in support of simulation validation.

  20. Stability studies of surficial sediments in the Wilmington-Lindenkohl Canyons area, eastern U.S. margin

    Science.gov (United States)

    Almagor, G.; Bennett, R.H.; Mc Gregor, B.A.; Shephard, L.E.

    1982-01-01

    Stability analysis, based on infinite slope analysis and geotechnical data from a suite of 34 cores collected from the continental slope between Wilmington and Lindenkohl Canyons, indicates that the Quaternary surficial silty clay sediments on gentle slopes are stable; that sediment stability on steeper slopes (14??-19??) is marginal; and that on precipitous slopes (>50??) only a thin veneer of unconsolidated sediments can exist. Small earthquake-induced accelerations or the effects of internal waves can result in slope sediment instabilities. ?? 1982 A. M. Dowden, Inc.

  1. Dynamical Stabilization of the Fermi Scale: Phase Diagram of Strongly Coupled Theories for (Minimal) Walking Technicolor and Unparticles

    CERN Document Server

    Sannino, Francesco

    2008-01-01

    We summarize basic features associated to dynamical breaking of the electroweak symmetry. The knowledge of the phase diagram of strongly coupled theories as function of the number of colors, flavors and matter representation plays a fundamental role when trying to construct viable extensions of the standard model (SM). Therefore we will report on the status of the phase diagram for SU(N) gauge theories with fermionic matter transforming according to arbitrary representations of the underlying gauge group. We will discuss how the phase diagram can be used to construct unparticle models. We will then review Minimal Walking Technicolor (MWT) and other extensions, such as partially gauged and split technicolor. MWT is a sufficiently general, symmetry wise, model to be considered as a benchmark for any model aiming at breaking the electroweak symmetry dynamically. The unification of the standard model gauge couplings will be revisited within technicolor extensions of the SM. A number of appendices are added to rev...

  2. Effect of Artificial Pitch Damping on the Longitudinal and Rolling Stability of Aircraft with Negative Static Margins

    Science.gov (United States)

    Moul, Martin T.; Brown, Lawrence W.

    1959-01-01

    A preliminary theoretical investigation has been made of the short-period longitudinal and steady-rolling (inertia coupling) stability of a hypersonic glider configuration for center-of-gravity locations rear-ward of the airplane neutral point. Such center-of-gravity positions for subsonic flight would improve performance by reducing supersonic and hypersonic static margins and trim drag. Results are presented of stability calculations and a simulator study for a velocity of 700 ft/sec and an altitude of 401,000 feet. With no augmentation, the airplane was rapidly divergent and was considered unsatisfactory in the simulator study. When a pitch damper was employed as a stability augmenter, the short-period mode became overdamped, and the airplane was easily controlled on the simulator. A steady-rolling analysis showed that the airplane can be made free of rolling divergence for all roll rates with an appropriate damper gain.

  3. Surface energy effects on the stability of anatase and rutile nanocrystals: A predictive diagram for Nb2O5-doped-TiO2

    Science.gov (United States)

    da Silva, Andre Luiz; Hotza, Dachamir; Castro, Ricardo H. R.

    2017-01-01

    Titanium dioxide nanoparticles are widely used for photocatalysis, and the relative fraction of titanium dioxide polymorph, i.e. anatase, rutile, or brookite, significantly affects the final performance. Even though conventional phase diagrams indicate a higher stability for the rutile polymorph, it is well established that nanosizes benefit the anatase phase due to its smaller surface energy. However, doping elements are expected to change this behavior, once changes in both surface and bulk energies may occur. Nb2O5 is commonly added to TiO2 to allow property control. However, the effect of niobium on the relative stability of anatase and rutile phases is not well understood from the thermodynamic point of view. The objective of this work was to build a new predictive nanoscale phase diagram for Nb2O5-doped TiO2. Water adsorption microcalorimetry and high temperature oxide melt solution were used to obtain the surface and bulk enthalpies. The phase diagram obtained shows the stable titania polymorph as a function of the composition and size.

  4. Excitation Spectra In Nongravitational Theories Marginal Stability, String Webs, Bound States In Gauge Theories And Hot Little Strings

    CERN Document Server

    Narayan, K S

    2002-01-01

    In this thesis, we discuss two topics—marginal stability in gauge theories and little string theories at the Hagedorn temperature. The spectrum of stable supersymmetric charged particle states can change discontinuously as we change the vacuum on the Coulomb branch of four dimensional gauge theories with extended supersymmetry. This discontinuous change manifests itself via the decay of some of these states which become marginally unstable across certain submanifolds in the Coulomb branch. We describe how this decay process can be studied through semiclassical field configurations, purely within the low energy effective action on the Coulomb branch, even at strong coupling. We then describe how these semiclassical field configurations naturally give rise to and generalize the string web description of these supersyrnmetric states found in D-brane constructions for some gauge theories. After a brief study of string web interactions in theories with sixteen supercharges, we move on to study the supers...

  5. Energy Optimization for Distributed Energy Resources Scheduling with Enhancements in Voltage Stability Margin

    DEFF Research Database (Denmark)

    Morais, Hugo; Sousa, Tiago; Perez, Angel

    2016-01-01

    The need for developing new methodologies in order to improve power system stability has increased due to the recent growth of distributed energy resources. In this paper, the inclusion of a voltage stability index in distributed energy resources scheduling is proposed. Two techniques were used...... resources is presented to analyse the proposed methodology. Additionally, the methodology is tested in a real distribution network....

  6. Energy Optimization for Distributed Energy Resources Scheduling with Enhancements in Voltage Stability Margin

    Directory of Open Access Journals (Sweden)

    Hugo Morais

    2016-01-01

    Full Text Available The need for developing new methodologies in order to improve power system stability has increased due to the recent growth of distributed energy resources. In this paper, the inclusion of a voltage stability index in distributed energy resources scheduling is proposed. Two techniques were used to evaluate the resulting multiobjective optimization problem: the sum-weighted Pareto front and an adapted goal programming methodology. With this new methodology, the system operators can consider both the costs and voltage stability. Priority can be assigned to one objective function according to the operating scenario. Additionally, it is possible to evaluate the impact of the distributed generation and the electric vehicles in the management of voltage stability in the future electric networks. One detailed case study considering a distribution network with high penetration of distributed energy resources is presented to analyse the proposed methodology. Additionally, the methodology is tested in a real distribution network.

  7. The role of zinc in the stability of the marginally stable IscU scaffold protein

    OpenAIRE

    Iannuzzi, Clara; Adrover, Miquel; Puglisi, Rita; Yan, Robert; Temussi, Piero Andrea; Pastore, Annalisa

    2014-01-01

    Understanding the factors that determine protein stability is interesting because it directly reflects the evolutionary pressure coming from function and environment. Here, we have combined experimental and computational methods to study the stability of IscU, a bacterial scaffold protein highly conserved in most organisms and an essential component of the iron–sulfur cluster biogenesis pathway. We demonstrate that the effect of zinc and its consequence strongly depend on the sample history. ...

  8. Electronic diagrams

    CERN Document Server

    Colwell, Morris A

    1976-01-01

    Electronic Diagrams is a ready reference and general guide to systems and circuit planning and in the preparation of diagrams for both newcomers and the more experienced. This book presents guidelines and logical procedures that the reader can follow and then be equipped to tackle large complex diagrams by recognition of characteristic 'building blocks' or 'black boxes'. The goal is to break down many of the barriers that often seem to deter students and laymen in learning the art of electronics, especially when they take up electronics as a spare time occupation. This text is comprised of nin

  9. Exceptionality and Peer Victimization Involvement in Late Childhood: Subtypes, Stability, and Social Marginalization

    Science.gov (United States)

    Chen, Chin-Chih; Hamm, Jill V.; Farmer, Thomas W.; Lambert, Kerrylin; Mehtaji, Meera

    2015-01-01

    This study examined subtypes and stability/change in peer victimization involvement among students with exceptionalities. Data were collected over spring of fifth grade and fall/spring of sixth grade with 1,861 students in 36 rural schools as part of a cluster randomized trial of a context-based intervention (Supporting Early Adolescent Learning…

  10. SCADA Diagram

    OpenAIRE

    Rose, Matthew

    2004-01-01

    Matthew Rose worked at the Naval Postgraduate School as a graphic designer from February 2002-November 2011. His work for NPS included logos, brochures, business packs, movies/presentations, posters, the CyberSiege video game and many other projects. This material was organized and provided by the artist, for inclusion in the NPS Archive, Calhoun. Includes these files: Plan_ver.ai; powerline.jpg; SCADA diagram.ai; SCADA diagram.pdf; SCADA diagramsmall.pdf; SCADA2.pdf

  11. Stability hierarchy between Piracetam forms I, II, and III from experimental pressure-temperature diagrams and topological inferences.

    Science.gov (United States)

    Toscani, Siro; Céolin, René; Minassian, Léon Ter; Barrio, Maria; Veglio, Nestor; Tamarit, Josep-Lluis; Louër, Daniel; Rietveld, Ivo B

    2016-01-30

    The trimorphism of the active pharmaceutical ingredient piracetam is a famous case of polymorphism that has been frequently revisited by many researchers. The phase relationships between forms I, II, and III were ambiguous because they seemed to depend on the heating rate of the DSC and on the history of the samples or they have not been observed at all (equilibrium II-III). In the present paper, piezo-thermal analysis and high-pressure differential thermal analysis have been used to elucidate the positions of the different solid-solid and solid-liquid equilibria. The phase diagram, involving the three solid phases, the liquid phase and the vapor phase, has been constructed. It has been shown that form III is the high-pressure, low-temperature form and the stable form at room temperature. Form II is stable under intermediary conditions and form I is the low pressure, high temperature form, which possesses a stable melting point. The present paper demonstrates the strength of the topological approach based on the Clapeyron equation and the alternation rule when combined with high-pressure measurements. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Implant stability and marginal bone level of microgrooved zirconia dental implants: A 3-month experimental study on dogs

    Directory of Open Access Journals (Sweden)

    Delgado-Ruíz Rafael Arcesio

    2014-01-01

    Full Text Available Background/Aim. The modification of implant surfaces could affect mechanical implant stability as well as dynamics and quality of peri-implant bone healing. The aim of this 3-month experimental study in dogs was to investigate implant stability, marginal bone levels and bone tissue response to zirconia dental implants with two laser-micro-grooved intraosseous surfaces in comparison with nongrooved sandblasted zirconia and sandblasted, high-temperature etched titanium implants. Methods. Implant surface characterization was performed using optical interferometric profilometry and energy dispersive X-ray spectroscopy. A total of 96 implants (4 mm in diameter and 10 mm in length were inserted randomly in both sides of the lower jaw of 12 Fox Hound dogs divided into groups of 24 each: the control (titanium, the group A (sandblasted zirconia, the group B (sandblasted zirconia plus microgrooved neck and the group C (sandblasted zirconia plus all microgrooved. All the implants were immediately loaded. Insertion torque, periotest values, radiographic crestal bone level and removal torque were recorded during the 3-month follow-up. Qualitative scanning electon micro-scope (SEM analysis of the bone-implant interfaces of each group was performed. Results. Insertion torque values were higher in the group C and control implants (p the control > the group B > the group A (p the control > the group B > the group A (p < 0.05. SEM showed that implant surfaces of the groups B and C had an extra bone growth inside the microgrooves that corresponded to the shape and direction of the microgrooves. Conclusion. The addition of micro-grooves to the entire intraosseous surface of zirconia dental implants enhances primary and secondary implant stability, promotes bone tissue ingrowth and preserves crestal bone levels.

  13. Delimiting diagrams

    NARCIS (Netherlands)

    Oostrom, V. van

    2008-01-01

    We introduce the unifying notion of delimiting diagram. Hitherto unrelated results such as: Minimality of the internal needed strategy for orthogonal first-order term rewriting systems, maximality of the limit strategy for orthogonal higher-order pattern rewrite systems (with maximality of the strat

  14. Determination of the E-pO{sup 2-} stability diagram of plutonium in the molten LiCl-KCl eutectic at 450 deg. C

    Energy Technology Data Exchange (ETDEWEB)

    Caravaca, Concha [CIEMAT, DE/DFN/URR, Avda. Complutense 22, Madrid 28040 (Spain)], E-mail: c.caravaca@ciemat.es; Laplace, Annabelle; Vermeulen, Jackie; Lacquement, Jerome [Commissariat a l' Energie Atomique, Site de Marcoule, DEN/DRCP/SCPS/LPP, Batiment 399, BP 17171, 30207 Bagnols sur Ceze (France)

    2008-07-01

    Plutonium trichloride solution in the molten LiCl-KCl eutectic was prepared by carbochlorination of plutonium oxide. Kinetics of this reaction was compared in different conditions in the range of 443-550 deg. C. Using this molten salt solution, the redox potential of the Pu(III)/Pu couple at inert tungsten electrode was measured at 450 deg. C by electromotive force measurement and was found to be E'{sup o} = -2.76 V vs. the Cl{sub 2(g)}(1 atm)/Cl{sup -} reference electrode (molar fraction scale). Reaction between plutonium trichloride and oxide ions was studied by potentiometric titration, using yttria stabilized electrodes. In our experimental conditions, the titration curves indicate the precipitation of the sesquioxide Pu{sub 2}O{sub 3}. The solubility product cologarithm calculated from these curves is found to be pK{sub s}(Pu{sub 2}O{sub 3}) = 22.8 {+-} 1.1 (molality scale). Using the experimentally obtained values for E'{sup o}, activity coefficient and pK{sub s} joined to the published thermodynamic data, the stability phase diagram of the Pu-O species was then drawn.

  15. Hubble Diagram

    Science.gov (United States)

    Djorgovski, S.; Murdin, P.

    2000-11-01

    Initially introduced as a way to demonstrate the expansion of the universe, and subsequently to determine the expansion rate (the HUBBLE CONSTANT H0), the Hubble diagram is one of the classical cosmological tests. It is a plot of apparent fluxes (usually expressed as magnitudes) of some types of objects at cosmological distances, against their REDSHIFTS. It is used as a tool to measure the glob...

  16. Immediately loaded mini dental implants as overdenture retainers: 1-Year cohort study of implant stability and peri-implant marginal bone level.

    Science.gov (United States)

    Šćepanović, Miodrag; Todorović, Aleksandar; Marković, Aleksa; Patrnogić, Vesna; Miličić, Biljana; Moufti, Adel M; Mišić, Tijana

    2015-05-01

    This 1-year cohort study investigated stability and peri-implant marginal bone level of immediately loaded mini dental implants used to retain overdentures. Each of 30 edentulous patients received 4 mini dental implants (1.8 mm × 13 mm) in the interforaminal mandibular region. The implants were immediately loaded with pre-made overdentures. Outcome measures included implant stability and bone resorption. Implant stability was measured using the Periotest Classic(®) device immediately after placement and on the 3rd and 6th weeks and the 4th, 6th and 12th months postoperatively. The peri-implant marginal bone level (PIBL) was evaluated at the implant's mesial and distal sides from the polished platform to the marginal crest. Radiographs were taken using a tailored film holder to reproducibly position the X-ray tube at the 6th week, 4th and 12th months postoperatively. The primary stability (Periotest value, PTV) measured -0.27 ± 3.41 on a scale of -8 to + 50 (lower PTV reflects higher stability). The secondary stability decreased significantly until week 6 (mean PTV = 7.61 ± 7.05) then increased significantly reaching (PTV = 6.17 ± 6.15) at 12 months. The mean PIBL measured -0.40 mm after 1 year of functional loading, with no statistically significant differences at the various follow-ups (p = 0.218). Mini dental implants placed into the interforaminal region could achieve a favorable primary stability for immediate loading. The follow-up Periotest values fluctuated, apparently reflecting the dynamics of bone remodeling, with the implants remaining clinically stable (98.3%) after 1 year of function. The 1-year bone resorption around immediately loaded MDIs is within the clinically acceptable range for standard implants. Copyright © 2014 Elsevier GmbH. All rights reserved.

  17. A new modeling of loading margin and its sensitivities using rectangular voltage coordinates in voltage stability analysis

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Vander Menengoy da; Rosa, Arlei Lucas de Sousa [Department of Electrical Engineering, Federal University of Juiz de Fora, Campus Universitario - Bairro Martelos, 36036-330 Juiz de Fora - MG (Brazil); Guedes, Magda Rocha [Federal Center of Technologic Education of Minas Gerais - CEFET, Rua Jose Peres, 558 36700-000 Leopoldina - MG (Brazil); Cantarino, Marcelo [Centrais Eletricas Brasileiras S.A - ELETROBRAS, Av. Rio Branco, 53, Centro, 14 andar, 20090-004 Rio de Janeiro - RJ (Brazil)

    2010-05-15

    This paper presents new mathematical models to compute the loading margin, as well as to perform the sensitivity analysis of loading margin with respect to different electric system parameters. The innovative idea consists of evaluating the performance of these methods when the power flow equations are expressed with the voltages in rectangular coordinates. The objective is to establish a comparative process with the conventional models expressed in terms of power flow equations with the voltages in polar coordinates. IEEE test system and a South-Southeastern Brazilian network are used in the simulations. (author)

  18. From State Diagram to Class Diagram

    DEFF Research Database (Denmark)

    Borch, Ole; Madsen, Per Printz

    2009-01-01

    UML class diagram and Java source code are interrelated and Java code is a kind of interchange format. Working with UML state diagram in CASE tools, a corresponding xml file is maintained. Designing state diagrams is mostly performed manually using design patterns and coding templates - a time...

  19. Stochastic subspsace parameter identification and stability diagram of gas-liquid two-phase flow patterns%基于随机子空间结合稳定图的气液两相流型分析

    Institute of Scientific and Technical Information of China (English)

    李洪伟; 周云龙; 刘旭; 孙斌

    2012-01-01

    The characteristics of stability diagram of several typical flow patterns are studied,and the signals of flow patterns under 47 kinds of flowing conditions are identified with stochastic subspace parameter identification.The results show that the characteristic of a stability diagram can reflect the internal characteristics of complex time series,the characteristics of time series can be quantified by extracted straightness characteristics and the differences of characteristics of stability diagrams of three typical flow patterns.The characteristics of stability diagrams of bubble flow are the most confused and followed by Mist flows'.Slug flows' are the most regular.The extraction and recognition for characteristics of gray fluctuation sequence of gas-liquid two-phase images and the accurate classification for flow pattern samples provide a new path for the classification of multi-phase flow patterns.At the same time,the stability diagram analysis method provides a useful exploration for the further revelation of flowing mechanism of multi-phase flows.%研究了儿种典型气液两相干流流型的稳定图特征,并应用随机子空间方法对47种流动条件下的流型信号进行了识别.研究结果表明:稳定图特征能够反映出复杂时间序列的内部特征,利用其提取的直线度特征值可以对时间序列的特征进行量化分析,三种典型流型的稳定图特征差异较明显,泡状流的稳定图特征最为混乱.雾状流次之.段塞流量为规整.应用随机子空间方法对气液两相流图像灰度波动序列进行特征向量提取和辨识,通过幅值以及相角的分布特征能够对不同工况下的流型样本进行准确分类,为多相流的分类提供了一条新路径.同时基于稳定图的分析方法为进一步揭示多相流的流动机理提供有益的探索.

  20. Methane Gas Hydrate Stability Models on Continental Shelves in Response to Glacio-Eustatic Sea Level Variations: Examples from Canadian Oceanic Margins

    Directory of Open Access Journals (Sweden)

    Jan Safanda

    2013-11-01

    Full Text Available We model numerically regions of the Canadian continental shelves during successive glacio-eustatic cycles to illustrate past, current and future marine gas hydrate (GH stability and instability. These models indicated that the marine GH resource has dynamic features and the formation age and resource volumes depend on the dynamics of the ocean-atmosphere system as it responds to both natural (glacial-interglacial and anthropogenic (climate change forcing. Our models focus on the interval beginning three million years ago (i.e., Late Pliocene-Holocene. They continue through the current interglacial and they are projected to its anticipated natural end. During the current interglacial the gas hydrate stability zone (GHSZ thickness in each region responded uniquely as a function of changes in water depth and sea bottom temperature influenced by ocean currents. In general, the GHSZ in the deeper parts of the Pacific and Atlantic margins (≥1316 m thinned primarily due to increased water bottom temperatures. The GHSZ is highly variable in the shallower settings on the same margins (~400–500 m. On the Pacific Margin shallow GH dissociated completely prior to nine thousand years ago but the effects of subsequent sea level rise reestablished a persistent, thin GHSZ. On the Atlantic Margin Scotian Shelf the warm Gulf Stream caused GHSZ to disappear completely, whereas in shallow water depths offshore Labrador the combination of the cool Labrador Current and sea level rise increased the GHSZ. If future ocean bottom temperatures remain constant, these general characteristics will persist until the current interglacial ends. If the sea bottom warms, possibly in response to global climate change, there could be a significant reduction to complete loss of GH stability, especially on the shallow parts of the continental shelf. The interglacial GH thinning rates constrain rates at which carbon can be transferred between the GH reservoir and the atmosphere

  1. A post-processing technique for stabilizing the discontinuous pressure projection operator in marginally-resolved incompressible inviscid flow

    CERN Document Server

    Joshi, Sumedh M; Steinmoeller, Derek T; Stastna, Marek; Thomsen, Greg N

    2015-01-01

    A method for post-processing the velocity after a pressure projection is developed that helps to maintain stability in an under-resolved, inviscid, discontinuous element-based simulation for use in environmental fluid mechanics process studies. The post-processing method is needed because of spurious divergence growth at element interfaces due to the discontinuous nature of the discretization used. This spurious divergence eventually leads to a numerical instability. Previous work has shown that a discontinuous element-local projection onto the space of divergence-free basis functions is capable of stabilizing the projection method, but the discontinuity inherent in this technique may lead to instability in under-resolved simulations. By enforcing inter-element discontinuity and requiring a divergence-free result in the weak sense only, a new post-processing technique is developed that simultaneously improves smoothness and reduces divergence in the pressure-projected velocity field at the same time. When com...

  2. FORM, Diagrams and Topologies

    CERN Document Server

    Herzog, Franz; Ueda, Takahiro; Vermaseren, J A M; Vogt, Andreas

    2016-01-01

    We discuss a number of FORM features that are essential in the automatic processing of very large numbers of diagrams as used in the Forcer program for 4-loop massless propagator diagrams. Most of these features are new.

  3. Extrinsic Curvature Embedding Diagrams

    CERN Document Server

    Lu, J L

    2003-01-01

    Embedding diagrams have been used extensively to visualize the properties of curved space in Relativity. We introduce a new kind of embedding diagram based on the {\\it extrinsic} curvature (instead of the intrinsic curvature). Such an extrinsic curvature embedding diagram, when used together with the usual kind of intrinsic curvature embedding diagram, carries the information of how a surface is {\\it embedded} in the higher dimensional curved space. Simple examples are given to illustrate the idea.

  4. Phase Equilibria Diagrams Database

    Science.gov (United States)

    SRD 31 NIST/ACerS Phase Equilibria Diagrams Database (PC database for purchase)   The Phase Equilibria Diagrams Database contains commentaries and more than 21,000 diagrams for non-organic systems, including those published in all 21 hard-copy volumes produced as part of the ACerS-NIST Phase Equilibria Diagrams Program (formerly titled Phase Diagrams for Ceramists): Volumes I through XIV (blue books); Annuals 91, 92, 93; High Tc Superconductors I & II; Zirconium & Zirconia Systems; and Electronic Ceramics I. Materials covered include oxides as well as non-oxide systems such as chalcogenides and pnictides, phosphates, salt systems, and mixed systems of these classes.

  5. Safety-barrier diagrams

    DEFF Research Database (Denmark)

    Duijm, Nijs Jan

    2007-01-01

    are discussed. A simple method for quantification of safety-barrier diagrams is proposed, including situations where safety barriers depend on shared common elements. It is concluded that safety-barrier diagrams provide a useful framework for an electronic data structure that integrates information from risk......Safety-barrier diagrams and the related so-called "bow-tie" diagrams have become popular methods in risk analysis. This paper describes the syntax and principles for constructing consistent and valid safety-barrier diagrams. The relation with other methods such as fault trees and Bayesian networks...... analysis with operational safety management....

  6. Materials Research Society Symposia Proceedings, Volume 19. Alloy Phase Diagrams Held November 1982 in Boston, Massachusetts.

    Science.gov (United States)

    Alloys, * Phase diagrams , *Symposia, Stability, Thermodynamic properties, Models, Solidification, Chemical equilibrium, Microstructure, Metallurgy, Structural analysis, Research management, Materials

  7. Atomic phase diagram

    Institute of Scientific and Technical Information of China (English)

    LI Shichun

    2004-01-01

    Based on the Thomas-Fermi-Dirac-Cheng model, atomic phase diagram or electron density versus atomic radius diagram describing the interaction properties of atoms of different kinds in equilibrium state is developed. Atomic phase diagram is established based on the two-atoms model. Besides atomic radius, electron density and continuity condition for electron density on interfaces between atoms, the lever law of atomic phase diagram involving other physical parameters is taken into account, such as the binding energy, for the sake of simplicity.

  8. Impact of coupling of lateral movement on missile stability margin%侧向运动耦合对导弹稳定裕度的影响

    Institute of Scientific and Technical Information of China (English)

    郭广明; 罗琴

    2013-01-01

    各通道间无耦合是工程上导弹控制系统设计的一个基本假设,但随着飞行速度及机动性的提高,导弹各通道间的气动与运动学耦合已不能忽略.以面对称导弹为研究对象,依据小扰动理论,通过建立偏航与滚转通道之间的耦合运动方程,定量分析了通道耦合对导弹控制系统稳定裕度的影响,所得结论可为面对称导弹的工程设计提供参考.%Abstract:No coupling between each channel is a basic assumption of the missile control system design on engineering,but with the flight speed and the mobility increased,aerodynamic and kinematic coupling between each channel of the missile can not be neglected.With plane symmetry missile as the research object,based on small perturbation theory and by establishing some coupled equations of motion between yaw and roll channels,this paper analyzes quantitatively the influence of channel coupling on stability margin.The conclusions can provide a reference for the engineering design of the plane symmetry missile.

  9. Difference Decision Diagrams

    DEFF Research Database (Denmark)

    Moeller, Jesper; Lichtenberg, Jacob; Andersen, Henrik Reif;

    1999-01-01

    This paper describes a new data structure, difference decision diagrams (DDDs), for representing a Boolean logic over inequalities of the form $x-y......This paper describes a new data structure, difference decision diagrams (DDDs), for representing a Boolean logic over inequalities of the form $x-y...

  10. Algorithmic phase diagrams

    Science.gov (United States)

    Hockney, Roger

    1987-01-01

    Algorithmic phase diagrams are a neat and compact representation of the results of comparing the execution time of several algorithms for the solution of the same problem. As an example, the recent results are shown of Gannon and Van Rosendale on the solution of multiple tridiagonal systems of equations in the form of such diagrams. The act of preparing these diagrams has revealed an unexpectedly complex relationship between the best algorithm and the number and size of the tridiagonal systems, which was not evident from the algebraic formulae in the original paper. Even so, for a particular computer, one diagram suffices to predict the best algorithm for all problems that are likely to be encountered the prediction being read directly from the diagram without complex calculation.

  11. Inductively generating Euler diagrams.

    Science.gov (United States)

    Stapleton, Gem; Rodgers, Peter; Howse, John; Zhang, Leishi

    2011-01-01

    Euler diagrams have a wide variety of uses, from information visualization to logical reasoning. In all of their application areas, the ability to automatically layout Euler diagrams brings considerable benefits. In this paper, we present a novel approach to Euler diagram generation. We develop certain graphs associated with Euler diagrams in order to allow curves to be added by finding cycles in these graphs. This permits us to build Euler diagrams inductively, adding one curve at a time. Our technique is adaptable, allowing the easy specification, and enforcement, of sets of well-formedness conditions; we present a series of results that identify properties of cycles that correspond to the well-formedness conditions. This improves upon other contributions toward the automated generation of Euler diagrams which implicitly assume some fixed set of well-formedness conditions must hold. In addition, unlike most of these other generation methods, our technique allows any abstract description to be drawn as an Euler diagram. To establish the utility of the approach, a prototype implementation has been developed.

  12. Polyoxometalate grafting onto silica: stability diagrams of H3PMo12O40 on {001}, {101}, and {111} β-cristobalite surfaces analyzed by DFT

    KAUST Repository

    Rozanska, Xavier

    2011-01-01

    The process of grafting H3PMo12O40 onto silica surfaces is studied using periodic density functional theory methods. For surfaces with a high hydroxyl coverage, the hydroxyl groups are consumed by the polyoxometalate protons, resulting in water formation and the creation of a covalent bond between the polyoxometalate and the surface, and mostly no remaining acidic proton on the polyoxometalate. When the surfaces are partially dehydroxylated and more hydrophobic, after temperature pretreatment, less covalent and hydrogen bonds are formed and the polyoxometalate tends to retain surface hydroxyl groups, while at least one acidic proton remains. Hence the hydroxylation of the surface has a great impact on the chemical properties of the grafted polyoxometalate. In return, the polyoxometalate species affects the compared stability of the partially hydroxylated silica surfaces in comparison with the bare silica case. © 2011 the Owner Societies.

  13. Engineering holographic phase diagrams

    Science.gov (United States)

    Chen, Jiunn-Wei; Dai, Shou-Huang; Maity, Debaprasad; Zhang, Yun-Long

    2016-10-01

    By introducing interacting scalar fields, we tried to engineer physically motivated holographic phase diagrams which may be interesting in the context of various known condensed matter systems. We introduce an additional scalar field in the bulk which provides a tunable parameter in the boundary theory. By exploiting the way the tuning parameter changes the effective masses of the bulk interacting scalar fields, desired phase diagrams can be engineered for the boundary order parameters dual to those scalar fields. We give a few examples of generating phase diagrams with phase boundaries which are strikingly similar to the known quantum phases at low temperature such as the superconducting phases. However, the important difference is that all the phases we have discussed are characterized by neutral order parameters. At the end, we discuss if there exists any emerging scaling symmetry associated with a quantum critical point hidden under the dome in this phase diagram.

  14. Feynman Diagrams for Beginners

    CERN Document Server

    Kumericki, Kresimir

    2016-01-01

    We give a short introduction to Feynman diagrams, with many exercises. Text is targeted at students who had little or no prior exposure to quantum field theory. We present condensed description of single-particle Dirac equation, free quantum fields and construction of Feynman amplitude using Feynman diagrams. As an example, we give a detailed calculation of cross-section for annihilation of electron and positron into a muon pair. We also show how such calculations are done with the aid of computer.

  15. Actively stressed marginal networks

    CERN Document Server

    Sheinman, M; MacKintosh, F C

    2012-01-01

    We study the effects of motor-generated stresses in disordered three dimensional fiber networks using a combination of a mean-field, effective medium theory, scaling analysis and a computational model. We find that motor activity controls the elasticity in an anomalous fashion close to the point of marginal stability by coupling to critical network fluctuations. We also show that motor stresses can stabilize initially floppy networks, extending the range of critical behavior to a broad regime of network connectivities below the marginal point. Away from this regime, or at high stress, motors give rise to a linear increase in stiffness with stress. Finally, we demonstrate that our results are captured by a simple, constitutive scaling relation highlighting the important role of non-affine strain fluctuations as a susceptibility to motor stress.

  16. Actively stressed marginal networks.

    Science.gov (United States)

    Sheinman, M; Broedersz, C P; MacKintosh, F C

    2012-12-07

    We study the effects of motor-generated stresses in disordered three-dimensional fiber networks using a combination of a mean-field theory, scaling analysis, and a computational model. We find that motor activity controls the elasticity in an anomalous fashion close to the point of marginal stability by coupling to critical network fluctuations. We also show that motor stresses can stabilize initially floppy networks, extending the range of critical behavior to a broad regime of network connectivities below the marginal point. Away from this regime, or at high stress, motors give rise to a linear increase in stiffness with stress. Finally, we demonstrate that our results are captured by a simple, constitutive scaling relation highlighting the important role of nonaffine strain fluctuations as a susceptibility to motor stress.

  17. Reading fitness landscape diagrams through HSAB concepts

    Energy Technology Data Exchange (ETDEWEB)

    Vigneresse, Jean-Louis, E-mail: jean-louis.vigneresse@univ-lorraine.fr

    2014-10-31

    Highlights: • Qualitative information from HSAB descriptors. • 2D–3D diagrams using chemical descriptors (χ, η, ω, α) and principles (MHP, mEP, mPP). • Estimate of the energy exchange during reaction paths. • Examples from complex systems (geochemistry). - Abstract: Fitness landscapes are conceived as range of mountains, with local peaks and valleys. In terms of potential, such topographic variations indicate places of local instability or stability. The chemical potential, or electronegativity, its value changed of sign, carries similar information. In addition to chemical descriptors defined through hard-soft acid-base (HSAB) concepts and computed through density functional theory (DFT), the principles that rule chemical reactions allow the design of such landscape diagrams. The simplest diagram uses electrophilicity and hardness as coordinates. It allows examining the influence of maximum hardness or minimum electrophilicity principles. A third dimension is introduced within such a diagram by mapping the topography of electronegativity, polarizability or charge exchange. Introducing charge exchange during chemical reactions, or mapping a third parameter (f.i. polarizability) reinforces the information carried by a simple binary diagram. Examples of such diagrams are provided, using data from Earth Sciences, simple oxides or ligands.

  18. Comparative evaluation of effects of bleaching on color stability and marginal adaptation of discolored direct and indirect composite laminate veneers under in vivo conditions

    National Research Council Canada - National Science Library

    Jain, Veena; Das, Taposh K; Pruthi, Gunjan; Shah, Naseem; Rajendiran, Suresh

    2015-01-01

    .... Bleaching is commonly used for treating discolored teeth. However, the literature is scanty regarding its effect on color and marginal adaptation of direct and indirect composite laminate veneers (CLVs...

  19. Mechanical stability model of progradational carbonate platform margins under tectonic loads: Deformation of Cretaceous carbonate platforms in the Sierra Madre Oriental fold-thrust belt (east central Mexico)

    Science.gov (United States)

    Contreras, Juan; Suter, Max

    2015-02-01

    Shortening in the Sierra Madre Oriental fold-thrust belt (east central Mexico) is localized along the margins of Cretaceous carbonate platforms and controlled by mechanical stratigraphy. The platform margins are deformed by imbricate series of thrust ramps, whereas the coeval basins and platform interiors are deformed by map-scale detachment folds. Here we present a finite element model to evaluate the influence of the boundary geometry and boundary conditions on the style of deformation observed at these basinward progradational platform margins. We calculate the stress distribution in a linearly elastic platform-basin transition zone under the action of horizontal tectonic stress, taking into account changes of rock mechanical properties across the platform margin, as well as their dependence on direction, and infer the resulting fracture patterns based on the Mohr-Coulomb failure criterion. Stress concentrations are predicted at the contacts between the massive rocks of the platform margin and the well-layered rocks of both, the platform interior and the adjacent basin. Brittle failure of the platform border can be mostly attributed to three effects: mechanical coupling between the carbonate platform and a substratum of moderate to low viscosity, variations in layering and texture that governed the mechanical properties of the involved carbonates as well as their dependence on direction, and the development of sharp domain boundary corners associated with progradational facies changes. In contrast, the dip of the basement and a possible taper of the overlying Upper Cretaceous shale toward the basin appear to have little influence on the mechanical failure of the platform margin.

  20. Equational binary decision diagrams

    NARCIS (Netherlands)

    Groote, J.F.; Pol, J.C. van de

    2000-01-01

    We incorporate equations in binary decision diagrams (BDD). The resulting objects are called EQ-BDDs. A straightforward notion of ordered EQ-BDDs (EQ-OBDD) is defined, and it is proved that each EQ-BDD is logically equivalent to an EQ-OBDD. Moreover, on EQ-OBDDs satisfiability and tautology checkin

  1. Limits of Voronoi Diagrams

    NARCIS (Netherlands)

    Lindenbergh, R.C.

    2002-01-01

    The classic Voronoi diagram of a configuration of distinct points in the plane associates to each point that part of the plane that is closer to the point than to any other point in the configuration. In this thesis we no longer require all points to be distinct. After the introduction in

  2. Equational binary decision diagrams

    NARCIS (Netherlands)

    J.F. Groote (Jan Friso); J.C. van de Pol (Jaco)

    2000-01-01

    textabstractWe incorporate equations in binary decision diagrams (BDD). The resulting objects are called EQ-BDDs. A straightforward notion of ordered EQ-BDDs (EQ-OBDD) is defined, and it is proved that each EQ-BDD is logically equivalent to an EQ-OBDD. Moreover, on EQ-OBDDs satisfiability and

  3. Compressing Binary Decision Diagrams

    DEFF Research Database (Denmark)

    Hansen, Esben Rune; Satti, Srinivasa Rao; Tiedemann, Peter

    2008-01-01

    The paper introduces a new technique for compressing Binary Decision Diagrams in those cases where random access is not required. Using this technique, compression and decompression can be done in linear time in the size of the BDD and compression will in many cases reduce the size of the BDD to 1...

  4. Compressing Binary Decision Diagrams

    DEFF Research Database (Denmark)

    Rune Hansen, Esben; Srinivasa Rao, S.; Tiedemann, Peter

    The paper introduces a new technique for compressing Binary Decision Diagrams in those cases where random access is not required. Using this technique, compression and decompression can be done in linear time in the size of the BDD and compression will in many cases reduce the size of the BDD to 1...

  5. On Argument and Diagrams.

    Science.gov (United States)

    Kneupper, Charles W.

    1978-01-01

    Responds to Charles Willard's recommendations (in an article in "Communication Monographs," November 1976) that argument be viewed as an attempt to establish formal relationships among symbolic structures. Demonstrates flaws in this redefinition and shows argument diagrams to be theoretically and practically justifiable. (JMF)

  6. Compressing Binary Decision Diagrams

    DEFF Research Database (Denmark)

    Hansen, Esben Rune; Satti, Srinivasa Rao; Tiedemann, Peter

    2008-01-01

    The paper introduces a new technique for compressing Binary Decision Diagrams in those cases where random access is not required. Using this technique, compression and decompression can be done in linear time in the size of the BDD and compression will in many cases reduce the size of the BDD to 1...

  7. Equational binary decision diagrams

    NARCIS (Netherlands)

    J.F. Groote (Jan Friso); J.C. van de Pol (Jaco)

    2000-01-01

    textabstractWe incorporate equations in binary decision diagrams (BDD). The resulting objects are called EQ-BDDs. A straightforward notion of ordered EQ-BDDs (EQ-OBDD) is defined, and it is proved that each EQ-BDD is logically equivalent to an EQ-OBDD. Moreover, on EQ-OBDDs satisfiability and tauto

  8. Generalized Ellingham diagrams for utilization in solid oxide fuel cells

    Directory of Open Access Journals (Sweden)

    Kishimoto H.

    2008-01-01

    Full Text Available Generalized Ellingham diagram for the P-O-H and the Ni-P-OH systems have been constructed to investigate thermodynamically the chemical stability of nickel anode against the gaseous impurities containing phosphorous compounds. In the same way as the original Ellingham diagram, the oxygen potential is used as the vertical axis, while the temperature is adopted as horizontal axis. For the P-O-H system which contains many gaseous species, the dominant areas of gaseous species are displayed with a parameter of their partial pressure in an analogous way to the aqueous species in the Pourbaix diagram. The multicomponent Ellingham diagram for the Ni-P-O-H system was constructed in a similar manner to the multicomponent Pourbaix diagram. The obtained diagrams have been discussed to examine the reactivity of nickel anodes with phosphorus compounds in SOFCs in terms of operational variables such as temperature, oxygen potential, overpotential under the anode polarization and so on.

  9. Phase diagram of ammonium nitrate

    Science.gov (United States)

    Dunuwille, M.; Yoo, C. S.

    2014-05-01

    Ammonium Nitrate (AN) has often subjected to uses in improvised explosive devices, due to its wide availability as a fertilizer and its capability of becoming explosive with slight additions of organic and inorganic compounds. Yet, the origin of enhanced energetic properties of impure AN (or AN mixtures) is neither chemically unique nor well understood -resulting in rather catastrophic disasters in the past1 and thereby a significant burden on safety in using ammonium nitrates even today. To remedy this situation, we have carried out an extensive study to investigate the phase stability of AN at high pressure and temperature, using diamond anvil cells and micro-Raman spectroscopy. The present results confirm the recently proposed phase IV-to-IV' transition above 17 GPa2 and provide new constraints for the melting and phase diagram of AN to 40 GPa and 400 °C.

  10. Alternative methodology for the margin determination of voltage stability in electrical power systems. Economical and technical impacts; Metodologia alternativa para a determinacao da margem de estabilidade de tensao em sistemas eletricos de potencia - impactos tecnicos e economicos

    Energy Technology Data Exchange (ETDEWEB)

    Cortez, Anderson Neves [Companhia Energetica de Minas Gerais (CEMIG), Belo Horizonte, MG (Brazil)]. E-mail: anderson@cemig.com.br

    2001-07-01

    This article presents an alternative methodology of voltage stability determination of Electrical Power System (EPS), focusing technical and economical aspects. In this direction, it presents relative aspects to mathematical modelling to analyse the phenomenon and also the influence from the most important dynamics to be taken into consideration. It is inquired the participation of generators in the rearrangement of the adopted active power in the current criteria of margin determination. A real system is analyzed, under this aspect, indicating significant variations in the calculated values for the margins, resulting in improper investments of significant values. The proposed methodology by this article seeks to contribute to minimize such mistakes, this is done by means of focusing the long duration dynamics of generators, what constitutes an important progress in relation to the researches about them.

  11. BLOCK DIAGRAM MODELS FOR CORRELATED STRUCTURES

    Directory of Open Access Journals (Sweden)

    Adrian Stere PARIS

    2016-05-01

    Full Text Available The copula function offers new opportunities for advanced engineering design and can model correlated structures between random variables in reliability; in other words the dependence can describe time varying and nonlinear features of statistical links of marginal distributions. The paper proposes the study of reliability block diagrams by the analysis of the bridge model with links like serial-parallel, parallel-serial, based on total probability formula. The proposed reliability model built by copula functions is a new possible variant for statistical approach in the quality practice.

  12. Boolean Expression Diagrams

    DEFF Research Database (Denmark)

    Andersen, Henrik Reif; Hulgaard, Henrik

    2002-01-01

    This paper presents a new data structure called boolean expression diagrams (BEDs) for representing and manipulating Boolean functions. BEDs are a generalization of binary decision diagrams (BDDs) which can represent any Boolean circuit in linear space. Two algorithms are described for transforming...... a BED into a reduced ordered BDD. One is a generalized version of the BDD apply-operator while the other can exploit the structural information of the Boolean expression. This ability is demonstrated by verifying that two different circuit implementations of a 16-bit multiplier implement the same...... Boolean function. Using BEDs, this verification problem is solved efficiently, while using standard BDD techniques this problem is infeasible. Generally, BEDs are useful in applications, for example tautology checking, where the end-result as a reduced ordered BDD is small. Moreover, using operators...

  13. Boolean Expression Diagrams

    DEFF Research Database (Denmark)

    Andersen, Henrik Reif; Hulgaard, Henrik

    1997-01-01

    This paper presents a new data structure called Boolean Expression Diagrams (BEDs) for representing and manipulating Boolean functions. BEDs are a generalization of Binary Decision Diagrams (BDDs) which can represent any Boolean circuit in linear space and still maintain many of the desirable...... properties of BDDs. Two algorithms are described for transforming a BED into a reduced ordered BDD. One closely mimics the BDD apply-operator while the other can exploit the structural information of the Boolean expression. The efficacy of the BED representation is demonstrated by verifying...... that the redundant and non-redundant versions of the ISCAS 85 benchmark circuits are identical. In particular, it is verified that the two 16-bit multiplication circuits (c6288 and c6288nr) implement the same Boolean functions. Using BEDs, this verification problem is solved in less than a second, while using...

  14. Peircean diagrams of time

    DEFF Research Database (Denmark)

    Øhrstrøm, Peter

    2011-01-01

    Some very good arguments can be given in favor of the Augustinean wisdom, according to which it is impossible to provide a satisfactory definition of the concept of time. However, even in the absence of a proper definition, it is possible to deal with conceptual problems regarding time. It can...... be done in terms of analogies and metaphors. In particular, it is attractive to make use of Peirce's diagrams by means of which various kinds of conceptual experimentation can be carried out. This paper investigates how Peircean diagrams can be used within the study of time. In particular, we discuss 1......) the topological properties of time, 2) the implicative structure in tense logic, 3) the notions of open future and branching time models, and finally 4) tenselogical alternatives to branching time models....

  15. TEP process flow diagram

    Energy Technology Data Exchange (ETDEWEB)

    Wilms, R Scott [Los Alamos National Laboratory; Carlson, Bryan [Los Alamos National Laboratory; Coons, James [Los Alamos National Laboratory; Kubic, William [Los Alamos National Laboratory

    2008-01-01

    This presentation describes the development of the proposed Process Flow Diagram (PFD) for the Tokamak Exhaust Processing System (TEP) of ITER. A brief review of design efforts leading up to the PFD is followed by a description of the hydrogen-like, air-like, and waterlike processes. Two new design values are described; the mostcommon and most-demanding design values. The proposed PFD is shown to meet specifications under the most-common and mostdemanding design values.

  16. Technology Logic Diagrams

    Energy Technology Data Exchange (ETDEWEB)

    Rudin, M.J. [Univ. of Nevada, Las Vegas NV (United States); O`Brien, M.C. [Univ. of Arizona, Tucson, AZ (United States)

    1995-04-01

    A planning and management tool was developed that relates environmental restoration and waste management problems to technologies that can be used to remediate these problems. Although the Technology Logic Diagram has been widely used within the US Department of Energy`s Office of Environmental Restoration and Waste Management, it can be modified for use during the planning of any waste management and environmental cleanup effort.

  17. The Massive Thermal Basketball Diagram

    CERN Document Server

    Andersen, J O; Strickland, Michael T; Andersen, Jens O.; Braaten, Eric; Strickland, Michael

    2000-01-01

    The "basketball diagram" is a three-loop vacuum diagram for a scalar fieldtheory that cannot be expressed in terms of one-loop diagrams. We calculatethis diagram for a massive scalar field at nonzero temperature, reducing it toexpressions involving three-dimensional integrals that can be easily evaluatednumerically. We use this result to calculate the free energy for a massivescalar field with a phi^4 interaction to three-loop order.

  18. Feynman diagram drawing made easy

    Science.gov (United States)

    Baillargeon, Marc; Nogueira, P.

    1997-02-01

    We present a drawing package optimised for Feynman diagrams. These can be constructed interactively with a mouse-driven graphical interface or from a script file, more suitable to work with a diagram generator. It provides most features encountered in Feynman diagrams and allows to modify every part of a diagram after its creation. Special attention has been paid to obtain a high quality printout as easily as possible. This package is written in Tcl/Tk and in C.

  19. Voronoi diagrams on the sphere

    NARCIS (Netherlands)

    Na, H.-S.; Lee, C.-N.; Cheong, O.

    2001-01-01

    Given a set of compact sites on a sphere, we show that their spherical Voronoi diagram can be computed by computing two planar Voronoi diagrams of suitably transformed sites in the plane. We also show that a planar furthest-site Voronoi diagram can always be obtained as a portion of a

  20. Phase Diagram Modelling: Nickel - Aluminum - Chromium System

    Science.gov (United States)

    1998-04-01

    conducted by Kaufman and co-workers and their lattice stabilities have formed the basis of phase diagram calculations to the present day.1 In...mol ( 0.74827 Ni + 0.73305E-01 Cr + 0.83609E-02 Al ( 1200.00 C, 1.0000 <—s -.Molten alloy <—s <—s) atm, L- NiCrAl , a=0.82994 ) 0.00000

  1. Margin requirements, margin loans, and margin rates: practice and principles

    OpenAIRE

    Peter Fortune

    2000-01-01

    The Board of Governors of the Federal Reserve System establishes initial margin requirements under Regulations T, U, and X. Recent margin loan increases, both in aggregate value and relative to market capitalization, have rekindled the debate about using margin requirements as an instrument to affect the prices of common stocks. Proponents of a more active margin requirement policy see the regulations as instruments for affecting the level and volatility of stock prices by influencing investo...

  2. Knot probabilities in random diagrams

    Science.gov (United States)

    Cantarella, Jason; Chapman, Harrison; Mastin, Matt

    2016-10-01

    We consider a natural model of random knotting—choose a knot diagram at random from the finite set of diagrams with n crossings. We tabulate diagrams with 10 and fewer crossings and classify the diagrams by knot type, allowing us to compute exact probabilities for knots in this model. As expected, most diagrams with 10 and fewer crossings are unknots (about 78% of the roughly 1.6 billion 10 crossing diagrams). For these crossing numbers, the unknot fraction is mostly explained by the prevalence of ‘tree-like’ diagrams which are unknots for any assignment of over/under information at crossings. The data shows a roughly linear relationship between the log of knot type probability and the log of the frequency rank of the knot type, analogous to Zipf’s law for word frequency. The complete tabulation and all knot frequencies are included as supplementary data.

  3. Collective neurodynamics: Phase diagram

    OpenAIRE

    Ovchinnikov, Igor V.; Li, Wenyuan; Schwartz, Robert N.; Hudson, Andrew E.; Meier, Karlheinz; Wang, Kang L.

    2016-01-01

    Here, we conceptualize the phase diagram of collective short-term bio-chemo-electric component of neurodynamics (S-ND) on the parameter space of externally, e.g., pharmacologically, controllable single-neuron parameters such as the resting potential and/or firing threshold, repolarization time, etc. This concept may become a useful tool for the systematization of knowledge in anesthesiology and provide a fruitful venue for future studies of the high-level S-ND functionalities such as short-te...

  4. Diagramming Complex Activities

    DEFF Research Database (Denmark)

    Andersen, Peter Bøgh

    2005-01-01

    We increasingly live in heterogeneous ever-changing webs of activities where human actions are intertwined with events created by automatic machines.  In order to make such webs understandable to its human participants, their structure should be represented by displays emphasizing their action as...... aspect. The paper suggests thematic roles as a semantics for actions, argues that a selection of well-known diagramming techniques can be defined within this theory, and uses the theory to discuss new issues related to process control and mobile technology....

  5. Petersen diagram revolution

    Science.gov (United States)

    Smolec, Radoslaw; Dziembowski, Wojciech; Moskalik, Pawel; Netzel, Henryka; Prudil, Zdenek; Skarka, Marek; Soszynski, Igor

    2017-09-01

    Over the recent years, the Petersen diagram for classical pulsators, Cepheids and RR Lyr stars, populated with a few hundreds of new multiperiodic variables. We review our analyses of the OGLE data, which resulted in a significant extension of the known, and in the discovery of a few new and distinct forms of multiperiodic pulsation. The showcase includes not only radial mode pulsators, but also radial-non-radial pulsators and stars with significant modulation observed on top of the beat pulsation. First theoretical models explaining the new forms of stellar variability are briefly discussed.

  6. Diagram for a small planet. The Production and Ecosystem Possibilities Curve

    Energy Technology Data Exchange (ETDEWEB)

    Haight, Alan Day [Economics Department, SUNY-Cortland, Old Main, Room 136A, Cortland, New York, 13045 (United States)

    2007-10-15

    With the development of the GPI there is now an ecological alternative to GDP for measuring a country's economic performance, but we still lack an ecological alternative to the PPC for illustrating a country's economic problem. The diagram suggested here illustrates a country's production and ecosystem possibilities - including climate stability, flood control, carbon sequestration, aquifer recharge, scenery, recreation, biological diversity, and so on. Burning a rainforest to clear the land shifts a country's PPC outward, giving the visual impression of an unmitigated improvement; but such development causes a movement along the country's PEPC, as ecosystem services are transformed into GDP. The slope of the PEPC is the marginal rate of transformation, which equals the ratio of the land's marginal marketable product to its marginal ecosystem product. Changes in technology create substitution and income effects that help explain the enclosure movement and the environmental Kuznets curve. Much as employment of the human resource can be restrained to allow more leisure, development of the natural resource can be restrained to preserve more ecosystem services. Commercial lobbying interests and rivalries for positional goods create distortions that move a country along its PEPC to a materialistic misallocation, with too little conservation. An idealistic misallocation is also possible, with too much preservation of the natural environment. Small is beautiful, up to a point, and that is evident in this diagram. Jacob Viner's [Viner, J., 1937. Studies in the Theory of International Trade. Harper and Brothers, New York] analytical objections to the PPC are revived. (author)

  7. Stabilization

    Directory of Open Access Journals (Sweden)

    Muhammad H. Al-Malack

    2016-07-01

    Full Text Available Fuel oil flyash (FFA produced in power and water desalination plants firing crude oils in the Kingdom of Saudi Arabia is being disposed in landfills, which increases the burden on the environment, therefore, FFA utilization must be encouraged. In the current research, the effect of adding FFA on the engineering properties of two indigenous soils, namely sand and marl, was investigated. FFA was added at concentrations of 5%, 10% and 15% to both soils with and without the addition of Portland cement. Mixtures of the stabilized soils were thoroughly evaluated using compaction, California Bearing Ratio (CBR, unconfined compressive strength (USC and durability tests. Results of these tests indicated that stabilized sand mixtures could not attain the ACI strength requirements. However, marl was found to satisfy the ACI strength requirement when only 5% of FFA was added together with 5% of cement. When the FFA was increased to 10% and 15%, the mixture’s strength was found to decrease to values below the ACI requirements. Results of the Toxicity Characteristics Leaching Procedure (TCLP, which was performed on samples that passed the ACI requirements, indicated that FFA must be cautiously used in soil stabilization.

  8. Phase-locked solutions and their stability in the presence of propagation delays

    Indian Academy of Sciences (India)

    Gautham C Sethia; Abhijit Sen; Fatihcan M Atay

    2011-11-01

    We investigate phase-locked solutions of a continuum field of nonlocally coupled identical phase oscillators with distance-dependent propagation delays. Equilibrium relations for both synchronous and travelling wave solutions in the parameter space characterizing the nonlocality and time delay are delineated. For the synchronous states a comprehensive stability diagram is presented that provides a heuristic synchronization condition as well as an analytic relation for the marginal stability curve. The relation yields simple stability expressions in the limiting cases of local and global coupling of phase oscillators.

  9. Program Synthesizes UML Sequence Diagrams

    Science.gov (United States)

    Barry, Matthew R.; Osborne, Richard N.

    2006-01-01

    A computer program called "Rational Sequence" generates Universal Modeling Language (UML) sequence diagrams of a target Java program running on a Java virtual machine (JVM). Rational Sequence thereby performs a reverse engineering function that aids in the design documentation of the target Java program. Whereas previously, the construction of sequence diagrams was a tedious manual process, Rational Sequence generates UML sequence diagrams automatically from the running Java code.

  10. Methane Gas Hydrate Stability Models on Continental Shelves in Response to Glacio-Eustatic Sea Level Variations: Examples from Canadian Oceanic Margins

    OpenAIRE

    2013-01-01

    We model numerically regions of the Canadian continental shelves during successive glacio-eustatic cycles to illustrate past, current and future marine gas hydrate (GH) stability and instability. These models indicated that the marine GH resource has dynamic features and the formation age and resource volumes depend on the dynamics of the ocean-atmosphere system as it responds to both natural (glacial-interglacial) and anthropogenic (climate change) forcing. Our models focus on the interval b...

  11. Diagonal Slices of 3D Young Diagrams in the Approach of Maya Diagrams

    Science.gov (United States)

    Cai, Li-Qiang; Wang, Li-Fang; Wu, Ke; Yang, Jie

    2014-09-01

    According to the correspondence between 2D Young diagrams and Maya diagrams and the relation between 2D and 3D Young diagrams, we construct 3D Young diagrams in the approach of Maya diagrams. Moreover, we formulate the generating function of 3D Young diagrams, which is the MacMahon function in terms of Maya diagrams.

  12. Diagrams and Proofs in Analysis

    DEFF Research Database (Denmark)

    Carter, Jessica M H Grund

    2010-01-01

    The article discusses the role of diagrams in mathematical reasoning based on a case study in analysis.   In the presented example certain combinatorial expressions were first found by using diagrams. In the published proofs the pictures are replaced by reasoning about permutation groups...

  13. Modeling process flow using diagrams

    NARCIS (Netherlands)

    Kemper, B.; de Mast, J.; Mandjes, M.

    2010-01-01

    In the practice of process improvement, tools such as the flowchart, the value-stream map (VSM), and a variety of ad hoc variants of such diagrams are commonly used. The purpose of this paper is to present a clear, precise, and consistent framework for the use of such flow diagrams in process

  14. Modeling process flow using diagrams

    NARCIS (Netherlands)

    Kemper, B.; de Mast, J.; Mandjes, M.

    2010-01-01

    In the practice of process improvement, tools such as the flowchart, the value-stream map (VSM), and a variety of ad hoc variants of such diagrams are commonly used. The purpose of this paper is to present a clear, precise, and consistent framework for the use of such flow diagrams in process improv

  15. Pitfalls and feedback when constructing topological pressure-temperature phase diagrams

    Science.gov (United States)

    Ceolin, R.; Toscani, S.; Rietveld, Ivo B.; Barrio, M.; Tamarit, J. Ll.

    2017-04-01

    The stability hierarchy between different phases of a chemical compound can be accurately reproduced in a topological phase diagram. This type of phase diagrams may appear to be the result of simple extrapolations, however, experimental complications quickly increase in the case of crystalline trimorphism (and higher order polymorphism). To ensure the accurate positioning of stable phase domains, a topological phase diagram needs to be consistent. This paper gives an example of how thermodynamic feedback can be used in the topological construction of phase diagrams to ensure overall consistency in a phase diagram based on the case of piracetam crystalline trimorphism.

  16. Genus Ranges of Chord Diagrams.

    Science.gov (United States)

    Burns, Jonathan; Jonoska, Nataša; Saito, Masahico

    2015-04-01

    A chord diagram consists of a circle, called the backbone, with line segments, called chords, whose endpoints are attached to distinct points on the circle. The genus of a chord diagram is the genus of the orientable surface obtained by thickening the backbone to an annulus and attaching bands to the inner boundary circle at the ends of each chord. Variations of this construction are considered here, where bands are possibly attached to the outer boundary circle of the annulus. The genus range of a chord diagram is the genus values over all such variations of surfaces thus obtained from a given chord diagram. Genus ranges of chord diagrams for a fixed number of chords are studied. Integer intervals that can be, and those that cannot be, realized as genus ranges are investigated. Computer calculations are presented, and play a key role in discovering and proving the properties of genus ranges.

  17. Stability

    Directory of Open Access Journals (Sweden)

    Nada S. Abdelwahab

    2017-05-01

    Full Text Available The present work concerns with the development of stability indicating the RP-HPLC method for simultaneous determination of guaifenesin (GUF and pseudoephedrine hydrochloride (PSH in the presence of guaifenesin related substance (Guaiacol. GUC, and in the presence of syrup excepients with minimum sample pre-treatment. In the developed RP-HPLC method efficient chromatographic separation was achieved for GUF, PSH, GUC and syrup excepients using ODS column as a stationary phase and methanol: water (50:50, v/v, pH = 4 with orthophosphoric acid as a mobile phase with a flow rate of 1 mL min−1 and UV detection at 210 nm. The chromatographic run time was approximately 10 min. Calibration curves were drawn relating the integrated area under peak to the corresponding concentrations of PSH, GUF and GUC in the range of 1–8, 1–20, 0.4–8 μg mL−1, respectively. The developed method has been validated and met the requirements delineated by ICH guidelines with respect to linearity, accuracy, precision, specificity and robustness. The validated method was successfully applied for determination of the studied drugs in triaminic chest congestion® syrup; moreover its results were statistically compared with those obtained by the official method and no significant difference was found between them.

  18. The Genesis of Feynman Diagrams

    CERN Document Server

    Wuthrich, Adrian

    2011-01-01

    In a detailed reconstruction of the genesis of Feynman diagrams the author reveals that their development was constantly driven by the attempt to resolve fundamental problems concerning the uninterpretable infinities that arose in quantum as well as classical theories of electrodynamic phenomena. Accordingly, as a comparison with the graphical representations that were in use before Feynman diagrams shows, the resulting theory of quantum electrodynamics, featuring Feynman diagrams, differed significantly from earlier versions of the theory in the way in which the relevant phenomena were concep

  19. Farthest-Polygon Voronoi Diagrams

    CERN Document Server

    Cheong, Otfried; Glisse, Marc; Gudmundsson, Joachim; Hornus, Samuel; Lazard, Sylvain; Lee, Mira; Na, Hyeon-Suk

    2010-01-01

    Given a family of k disjoint connected polygonal sites in general position and of total complexity n, we consider the farthest-site Voronoi diagram of these sites, where the distance to a site is the distance to a closest point on it. We show that the complexity of this diagram is O(n), and give an O(n log^3 n) time algorithm to compute it. We also prove a number of structural properties of this diagram. In particular, a Voronoi region may consist of k-1 connected components, but if one component is bounded, then it is equal to the entire region.

  20. Scattering equations and Feynman diagrams

    Science.gov (United States)

    Baadsgaard, Christian; Bjerrum-Bohr, N. E. J.; Bourjaily, Jacob L.; Damgaard, Poul H.

    2015-09-01

    We show a direct matching between individual Feynman diagrams and integration measures in the scattering equation formalism of Cachazo, He and Yuan. The connection is most easily explained in terms of triangular graphs associated with planar Feynman diagrams in φ 3-theory. We also discuss the generalization to general scalar field theories with φ p interactions, corresponding to polygonal graphs involving vertices of order p. Finally, we describe how the same graph-theoretic language can be used to provide the precise link between individual Feynman diagrams and string theory integrands.

  1. Scattering Equations and Feynman Diagrams

    CERN Document Server

    Baadsgaard, Christian; Bourjaily, Jacob L; Damgaard, Poul H

    2015-01-01

    We show a direct matching between individual Feynman diagrams and integration measures in the scattering equation formalism of Cachazo, He and Yuan. The connection is most easily explained in terms of triangular graphs associated with planar Feynman diagrams in $\\phi^3$-theory. We also discuss the generalization to general scalar field theories with $\\phi^p$ interactions, corresponding to polygonal graphs involving vertices of order $p$. Finally, we describe how the same graph-theoretic language can be used to provide the precise link between individual Feynman diagrams and string theory integrands.

  2. The Eh-pH Diagram and Its Advances

    Directory of Open Access Journals (Sweden)

    Hsin-Hsiung Huang

    2016-01-01

    Full Text Available Since Pourbaix presented Eh versus pH diagrams in his “Atlas of Electrochemical Equilibria in Aqueous Solution”, diagrams have become extremely popular and are now used in almost every scientific area related to aqueous chemistry. Due to advances in personal computers, such diagrams can now show effects not only of Eh and pH, but also of variables, including ligand(s, temperature and pressure. Examples from various fields are illustrated in this paper. Examples include geochemical formation, corrosion and passivation, precipitation and adsorption for water treatment and leaching and metal recovery for hydrometallurgy. Two basic methods were developed to construct an Eh-pH diagram concerning the ligand component(s. The first method calculates and draws a line between two adjacent species based on their given activities. The second method performs equilibrium calculations over an array of points (500 × 800 or higher are preferred, each representing one Eh and one pH value for the whole system, then combines areas of each dominant species for the diagram. These two methods may produce different diagrams. The fundamental theories, illustrated results, comparison and required conditions behind these two methods are presented and discussed in this paper. The Gibbs phase rule equation for an Eh-pH diagram was derived and verified from actual plots. Besides indicating the stability area of water, an Eh-pH diagram normally shows only half of an overall reaction. However, merging two or more related diagrams together reveals more clearly the possibility of the reactions involved. For instance, leaching of Au with cyanide followed by cementing Au with Zn (Merrill-Crowe process can be illustrated by combining Au-CN and Zn-CN diagrams together. A second example of the galvanic conversion of chalcopyrite can be explained by merging S, Fe–S and Cu–Fe–S diagrams. The calculation of an Eh-pH diagram can be extended easily into another dimension, such

  3. Particles, Feynman Diagrams and All That

    Science.gov (United States)

    Daniel, Michael

    2006-01-01

    Quantum fields are introduced in order to give students an accurate qualitative understanding of the origin of Feynman diagrams as representations of particle interactions. Elementary diagrams are combined to produce diagrams representing the main features of the Standard Model.

  4. Causal diagrams for physical models

    CERN Document Server

    Kinsler, Paul

    2015-01-01

    I present a scheme of drawing causal diagrams based on physically motivated mathematical models expressed in terms of temporal differential equations. They provide a means of better understanding the processes and causal relationships contained within such systems.

  5. Bayesian Networks and Influence Diagrams

    DEFF Research Database (Denmark)

    Kjærulff, Uffe Bro; Madsen, Anders Læsø

     Probabilistic networks, also known as Bayesian networks and influence diagrams, have become one of the most promising technologies in the area of applied artificial intelligence, offering intuitive, efficient, and reliable methods for diagnosis, prediction, decision making, classification......, troubleshooting, and data mining under uncertainty. Bayesian Networks and Influence Diagrams: A Guide to Construction and Analysis provides a comprehensive guide for practitioners who wish to understand, construct, and analyze intelligent systems for decision support based on probabilistic networks. Intended...

  6. Wind Diagrams in Medieval Iceland

    DEFF Research Database (Denmark)

    Kedwards, Dale

    2014-01-01

    This article presents a study of the sole wind diagram that survives from medieval Iceland, preserved in the encyclopaedic miscellany in Copenhagen's Arnamagnæan Institute with the shelf mark AM 732b 4to (c. 1300-25). It examines the wind diagram and its accompanying text, an excerpt on the winds...... from Isidore of Seville's Etymologies. It also examines the perimeter of winds on two medieval Icelandic world maps, and the visual traditions from which they draw....

  7. Ion mixing and phase diagrams

    Science.gov (United States)

    Lau, S. S.; Liu, B. X.; Nicolet, M.-A.

    1983-05-01

    Interactions induced by ion irradiation are generally considered to be non-equilibrium processes, whereas phase diagrams are determined by phase equilibria. These two entities are seemingly unrelated. However, if one assumes that quasi-equilibrium conditions prevail after the prompt events, subsequent reactions are driven toward equilibrium by thermodynamical forces. Under this assumption, ion-induced reactions are related to equilibrium and therefore to phase diagrams. This relationship can be seen in the similarity that exists in thin films between reactions induced by ion irradiation and reactions induced by thermal annealing. In the latter case, phase diagrams have been used to predict the phase sequence of stable compound formation, notably so in cases of silicide formation. Ion-induced mixing not only can lead to stable compound formation, but also to metastable alloy formation. In some metal-metal systems, terminal solubilities can be greatly extended by ion mixing. In other cases, where the two constituents of the system have different crystal structures, extension of terminal solubility from both sides of the phase diagram eventually becomes structurally incompatible and a glassy (amorphous) mixture can form. The composition range where this bifurcation is likely to occur is in the two-phase regions of the phase diagram. These concepts are potentially useful guides in selecting metal pairs that from metallic glasses by ion mixing. In this report, phenomenological correlation between stable (and metastable) phase formation and phase diagram is discussed in terms of recent experimental data.

  8. Marginally Stable Nuclear Burning

    Science.gov (United States)

    Strohmayer, Tod E.; Altamirano, D.

    2012-01-01

    Thermonuclear X-ray bursts result from unstable nuclear burning of the material accreted on neutron stars in some low mass X-ray binaries (LMXBs). Theory predicts that close to the boundary of stability oscillatory burning can occur. This marginally stable regime has so far been identified in only a small number of sources. We present Rossi X-ray Timing Explorer (RXTE) observations of the bursting, high-inclination LMXB 4U 1323-619 that reveal for the first time in this source the signature of marginally stable burning. The source was observed during two successive RXTE orbits for approximately 5 ksec beginning at 10:14:01 UTC on March 28, 2011. Significant mHz quasi-periodic oscillations (QPO) at a frequency of 8.1 mHz are detected for approximately 1600 s from the beginning of the observation until the occurrence of a thermonuclear X-ray burst at 10:42:22 UTC. The mHz oscillations are not detected following the X-ray burst. The average fractional rms amplitude of the mHz QPOs is 6.4% (3 - 20 keV), and the amplitude increases to about 8% below 10 keV.This phenomenology is strikingly similar to that seen in the LMXB 4U 1636-53. Indeed, the frequency of the mHz QPOs in 4U 1323-619 prior to the X-ray burst is very similar to the transition frequency between mHz QPO and bursts found in 4U 1636-53 by Altamirano et al. (2008). These results strongly suggest that the observed QPOs in 4U 1323-619 are, like those in 4U 1636-53, due to marginally stable nuclear burning. We also explore the dependence of the energy spectrum on the oscillation phase, and we place the present observations within the context of the spectral evolution of the accretion-powered flux from the source.

  9. Perfect orderings on Bratteli diagrams

    CERN Document Server

    Bezuglyi, Sergey; Yassawi, Reem

    2012-01-01

    Given a Bratteli diagram B, we study the set O(B) of all possible orderings w on a Bratteli diagram B and its subset P(B) consisting of `perfect' orderings that produce Bratteli-Vershik dynamical systems (Vershik maps). We give necessary and sufficient conditions for w to be perfect. On the other hand, a wide class of non-simple Bratteli diagrams that do not admit Vershik maps is explicitly described. In the case of finite rank Bratteli diagrams, we show that the existence of perfect orderings with a prescribed number of extreme paths affects significantly the values of the entries of the incidence matrices and the structure of the diagram B. Endowing the set O(B) with product measure, we prove that there is some j such that almost all orderings on B have j maximal and minimal paths, and that if j is strictly greater than the number of minimal components that B has, then almost all orderings are imperfect.

  10. Improving modeling with layered UML diagrams

    DEFF Research Database (Denmark)

    Störrle, Harald

    2013-01-01

    Layered diagrams are diagrams whose elements are organized into sets of layers. Layered diagrams are routinely used in many branches of engineering, except Software Engineering. In this paper, we propose to add layered diagrams to UML modeling tools, and elaborate the concept by exploring usage...

  11. Nonabelian cut diagrams and their applications

    CERN Document Server

    Lam, C S

    1996-01-01

    A new kind of cut diagram is introduced to sum Feynman diagrams with nonabelian vertices. Unlike the Cutkosky diagrams which compute the discontinuity of single Feynman diagrams, the nonabelian cut diagrams represent a resummation of both the real and the imaginary parts of Feynman diagrams related by permutations. Several applications of the technique are reported, including a resolution of the apparent inconsistency of the baryon problem in large-N_c QCD, a simplified calculation of high-energy low-order QCD diagrams, and progress made with this technique on the unitarization of the BFKL equation.

  12. Visualizing spacetimes via embedding diagrams

    CERN Document Server

    Hledik, Stanislav; Cipko, Alois

    2016-01-01

    It is hard to imagine curved spacetimes of General Relativity. A simple but powerful way how to achieve this is visualizing them via embedding diagrams of both ordinary geometry and optical reference geometry. They facilitate to gain an intuitive insight into the gravitational field rendered into a curved spacetime, and to assess the influence of parameters like electric charge and spin of a black hole, magnetic field or cosmological constant. Optical reference geometry and related inertial forces and their relationship to embedding diagrams are particularly useful for investigation of test particles motion. Embedding diagrams of static and spherically symmetric, or stationary and axially symmetric black-hole and naked-singularity spacetimes thus present a useful concept for intuitive understanding of these spacetimes' nature. We concentrate on general way of embedding into 3-dimensional Euclidean space, and give a set of illustrative examples.

  13. Flight control systems properties and problems. Volume 2: Block diagram compendium

    Science.gov (United States)

    Johnston, D. E.

    1975-01-01

    A compendium of stability augmentation system and autopilot block diagrams is presented. Descriptive materials for 48 different types of aircraft systems are provided. A broad representation of the many mechanical approaches which have been used for aircraft control is developed.

  14. Bayesian Networks and Influence Diagrams

    DEFF Research Database (Denmark)

    Kjærulff, Uffe Bro; Madsen, Anders Læsø

    Bayesian Networks and Influence Diagrams: A Guide to Construction and Analysis, Second Edition, provides a comprehensive guide for practitioners who wish to understand, construct, and analyze intelligent systems for decision support based on probabilistic networks. This new edition contains six new...

  15. Electrical elementary diagrams and operators

    Energy Technology Data Exchange (ETDEWEB)

    Patterson, B.K. [Human Factors Practical Inc., Dipper Harbour, New Brunswick (Canada)]. E-mail: HumanFactors@netscape.ca

    2005-07-01

    After 40 years of reading and interrupting electrical elementary logic drawings, I have concluded that we need to make a change. We need to write and express our nuclear power plant logic in some other language than relay ladder logic, solid state logic or computer mnemonics. The language should be English, or your native language, and the format should be Descriptive Block Diagrams. (author)

  16. The diagram for phyllotactic series

    Directory of Open Access Journals (Sweden)

    Joanna Szymanowska-Pułka

    2014-01-01

    Full Text Available Many authors studying phyllotaxis in various plant species have reported the occurrence of many different numbers of contact parastichy pairs that are members of different Fibonacci-like series. On the basis of these reports a diagram was constructed in which any theoretically possible series was represented by the two first members of a given series.

  17. BIHOURLY DIAGRAMS OF FORBUSH DECREASES

    Science.gov (United States)

    Bihourly diagrams were made of Forbush decreases of cosmic ray intensity as observed at Uppsala from 31 Aug 56 to 31 Dec 59, at Kiruna from Nov 56 to 31 Dec 59, and at Murchison Bay from 26 Aug 57 to 30 Apr 59. (Author)

  18. Phase diagram of Hertzian spheres

    NARCIS (Netherlands)

    Pàmies, J.C.; Cacciuto, A.; Frenkel, D.

    2009-01-01

    We report the phase diagram of interpenetrating Hertzian spheres. The Hertz potential is purely repulsive, bounded at zero separation, and decreases monotonically as a power law with exponent 5/2, vanishing at the overlapping threshold. This simple functional describes the elastic interaction of wea

  19. Bayesian Networks and Influence Diagrams

    DEFF Research Database (Denmark)

    Kjærulff, Uffe Bro; Madsen, Anders Læsø

    Bayesian Networks and Influence Diagrams: A Guide to Construction and Analysis, Second Edition, provides a comprehensive guide for practitioners who wish to understand, construct, and analyze intelligent systems for decision support based on probabilistic networks. This new edition contains six new...

  20. Multi-currency Influence Diagrams

    DEFF Research Database (Denmark)

    Nielsen, Søren Holbech; Nielsen, Thomas Dyhre; Jensen, Finn V.

    2007-01-01

    When using the influence diagrams framework for solving a decision problem with several different quantitative utilities, the traditional approach has been to convert the utilities into one common currency. This conversion is carried out using a tacit transformation, under the assumption that the...

  1. Multi-currency Influence Diagrams

    DEFF Research Database (Denmark)

    Nielsen, Søren Holbech; Nielsen, Thomas Dyhre; Jensen, Finn Verner

    2004-01-01

    that the converted problem is equivalent to the original one. In this paper we present an extension of the Influence Diagram framework, which allows for these decision problems to be modelled in their original form. We present an algorithm that, given a conversion function between the currencies, discovers...

  2. Marginalization of the Youth

    DEFF Research Database (Denmark)

    Jensen, Niels Rosendal

    2009-01-01

    The article is based on a key note speach in Bielefeld on the subject "welfare state and marginalized youth", focusing upon the high ambition of expanding schooling in Denmark from 9 to 12 years. The unintended effect may be a new kind of marginalization.......The article is based on a key note speach in Bielefeld on the subject "welfare state and marginalized youth", focusing upon the high ambition of expanding schooling in Denmark from 9 to 12 years. The unintended effect may be a new kind of marginalization....

  3. Practical Marginalized Multilevel Models.

    Science.gov (United States)

    Griswold, Michael E; Swihart, Bruce J; Caffo, Brian S; Zeger, Scott L

    2013-01-01

    Clustered data analysis is characterized by the need to describe both systematic variation in a mean model and cluster-dependent random variation in an association model. Marginalized multilevel models embrace the robustness and interpretations of a marginal mean model, while retaining the likelihood inference capabilities and flexible dependence structures of a conditional association model. Although there has been increasing recognition of the attractiveness of marginalized multilevel models, there has been a gap in their practical application arising from a lack of readily available estimation procedures. We extend the marginalized multilevel model to allow for nonlinear functions in both the mean and association aspects. We then formulate marginal models through conditional specifications to facilitate estimation with mixed model computational solutions already in place. We illustrate the MMM and approximate MMM approaches on a cerebrovascular deficiency crossover trial using SAS and an epidemiological study on race and visual impairment using R. Datasets, SAS and R code are included as supplemental materials.

  4. Hero's journey in bifurcation diagram

    Science.gov (United States)

    Monteiro, L. H. A.; Mustaro, P. N.

    2012-06-01

    The hero's journey is a narrative structure identified by several authors in comparative studies on folklore and mythology. This storytelling template presents the stages of inner metamorphosis undergone by the protagonist after being called to an adventure. In a simplified version, this journey is divided into three acts separated by two crucial moments. Here we propose a discrete-time dynamical system for representing the protagonist's evolution. The suffering along the journey is taken as the control parameter of this system. The bifurcation diagram exhibits stationary, periodic and chaotic behaviors. In this diagram, there are transition from fixed point to chaos and transition from limit cycle to fixed point. We found that the values of the control parameter corresponding to these two transitions are in quantitative agreement with the two critical moments of the three-act hero's journey identified in 10 movies appearing in the list of the 200 worldwide highest-grossing films.

  5. Anatomy of geodesic Witten diagrams

    Science.gov (United States)

    Chen, Heng-Yu; Kuo, En-Jui; Kyono, Hideki

    2017-05-01

    We revisit the so-called "Geodesic Witten Diagrams" (GWDs) [1], proposed to be the holographic dual configuration of scalar conformal partial waves, from the perspectives of CFT operator product expansions. To this end, we explicitly consider three point GWDs which are natural building blocks of all possible four point GWDs, discuss their gluing procedure through integration over spectral parameter, and this leads us to a direct identification with the integral representation of CFT conformal partial waves. As a main application of this general construction, we consider the holographic dual of the conformal partial waves for external primary operators with spins. Moreover, we consider the closely related "split representation" for the bulk to bulk spinning propagator, to demonstrate how ordinary scalar Witten diagram with arbitrary spin exchange, can be systematically decomposed into scalar GWDs. We also discuss how to generalize to spinning cases.

  6. Hubble's diagram and cosmic expansion

    OpenAIRE

    Kirshner, Robert P.

    2003-01-01

    Edwin Hubble's classic article on the expanding universe appeared in PNAS in 1929 [Hubble, E. P. (1929) Proc. Natl. Acad. Sci. USA 15, 168–173]. The chief result, that a galaxy's distance is proportional to its redshift, is so well known and so deeply embedded into the language of astronomy through the Hubble diagram, the Hubble constant, Hubble's Law, and the Hubble time, that the article itself is rarely referenced. Even though Hubble's distances have a large systematic error, Hubble's velo...

  7. Hubble's diagram and cosmic expansion

    OpenAIRE

    Kirshner, Robert P.

    2003-01-01

    Edwin Hubble's classic article on the expanding universe appeared in PNAS in 1929 [Hubble, E. P. (1929) Proc. Natl. Acad. Sci. USA 15, 168–173]. The chief result, that a galaxy's distance is proportional to its redshift, is so well known and so deeply embedded into the language of astronomy through the Hubble diagram, the Hubble constant, Hubble's Law, and the Hubble time, that the article itself is rarely referenced. Even though Hubble's distances have a large systematic error, Hubble's velo...

  8. Reliability computation from reliability block diagrams

    Science.gov (United States)

    Chelson, P. O.; Eckstein, E. Y.

    1975-01-01

    Computer program computes system reliability for very general class of reliability block diagrams. Four factors are considered in calculating probability of system success: active block redundancy, standby block redundancy, partial redundancy, and presence of equivalent blocks in the diagram.

  9. Phase diagram of crushed powders

    Science.gov (United States)

    Bodard, Sébastien; Jalbaud, Olivier; Saurel, Richard; Burtschell, Yves; Lapebie, Emmanuel

    2016-12-01

    Compression of monodisperse powder samples in quasistatic conditions is addressed in a pressure range such that particles fragmentation occurs while the solid remains incompressible (typical pressure range of 1-300 MPa for glass powders). For a granular bed made of particles of given size, the existence of three stages is observed during compression and crush up. First, classical compression occurs and the pressure of the granular bed increases along a characteristic curve as the volume decreases. Then, a critical pressure is reached for which fragmentation begins. During the fragmentation process, the granular pressure stays constant in a given volume range. At the end of this second stage, 20%-50% of initial grains are reduced to finer particles, depending on the initial size. Then the compression undergoes the third stage and the pressure increases along another characteristic curve, in the absence of extra fragmentation. The present paper analyses the analogies between the phase transition in liquid-vapour systems and powder compression with crush-up. Fragmentation diagram for a soda lime glass is determined by experimental means. The analogues of the saturation pressure and latent heat of phase change are determined. Two thermodynamic models are then examined to represent the crush-up diagram. The first one uses piecewise functions while the second one is of van der Waals type. Both equations of state relate granular pressure, solid volume fraction, and initial particle diameter. The piecewise functions approach provides reasonable representations of the phase diagram while the van der Waals one fails.

  10. Scheil-Gulliver Constituent Diagrams

    Science.gov (United States)

    Pelton, Arthur D.; Eriksson, Gunnar; Bale, Christopher W.

    2017-03-01

    During solidification of alloys, conditions often approach those of Scheil-Gulliver cooling in which it is assumed that solid phases, once precipitated, remain unchanged. That is, they no longer react with the liquid or with each other. In the case of equilibrium solidification, equilibrium phase diagrams provide a valuable means of visualizing the effects of composition changes upon the final microstructure. In the present study, we propose for the first time the concept of Scheil-Gulliver constituent diagrams which play the same role as that in the case of Scheil-Gulliver cooling. It is shown how these diagrams can be calculated and plotted by the currently available thermodynamic database computing systems that combine Gibbs energy minimization software with large databases of optimized thermodynamic properties of solutions and compounds. Examples calculated using the FactSage system are presented for the Al-Li and Al-Mg-Zn systems, and for the Au-Bi-Sb-Pb system and its binary and ternary subsystems.

  11. The evolution and evolutionary consequences of marginal thermostability in proteins.

    Science.gov (United States)

    Goldstein, Richard A

    2011-05-01

    When we seek to explain the characteristics of living systems in their evolutionary context, we are often interested in understanding how and why certain properties arose through evolution, and how these properties then affected the continuing evolutionary process. This endeavor has been assisted by the use of simple computational models that have properties characteristic of natural living systems but allow simulations over evolutionary timescales with full transparency. We examine a model of the evolution of a gene under selective pressure to code for a protein that exists in a prespecified folded state at a given growth temperature. We observe the emergence of proteins with modest stabilities far below those possible with the model, with a denaturation temperature tracking the simulation temperature, despite the absence of selective pressure for such marginal stability. This demonstrates that neither observations of marginally stable proteins, nor even instances where increased stability interferes with function, provide evidence that marginal stability is an adaptation. Instead the marginal stability is the result of a balance between predominantly destabilizing mutations and selection that shifts depending on effective population size. Even if marginal stability is not an adaptation, the natural tendency of proteins toward marginal stability, and the range of stabilities that occur during evolution, may have significant effect on the evolutionary process.

  12. Operations space diagram for ECRH and ECCD

    DEFF Research Database (Denmark)

    Bindslev, H.

    2004-01-01

    A Clemmov-Mullaly-Allis (CMA) type diagram, the ECW-CMA diagram, for representing the operational possibilities of electron cyclotron heating and current drive (ECRH/ECCD) systems for fusion plasmas is presented. In this diagram, with normalized density and normalized magnetic field coordinates...

  13. Ocean margins workshop

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1990-12-31

    The Department of Energy (DOE) is announcing the refocusing of its marine research program to emphasize the study of ocean margins and their role in modulating, controlling, and driving Global Change phenomena. This is a proposal to conduct a workshop that will establish priorities and an implementation plan for a new research initiative by the Department of Energy on the ocean margins. The workshop will be attended by about 70 scientists who specialize in ocean margin research. The workshop will be held in the Norfolk, Virginia area in late June 1990.

  14. "We call ourselves marginalized"

    DEFF Research Database (Denmark)

    Jørgensen, Nanna Jordt

    2014-01-01

    In recent decades, indigenous knowledge has been added to the environmental education agenda in an attempt to address the marginalization of non-western perspectives. While these efforts are necessary, the debate is often framed in terms of a discourse of victimization that overlooks the agency o...... argue that researchers not only need to pay attention to how certain voices are marginalized in Environmental Education research and practice, but also to how learners as agents respond to, use and negotiate the marginalization of their perspectives....

  15. Diagram, a Learning Environment for Initiation to Object-Oriented Modeling with UML Class Diagrams

    Science.gov (United States)

    Py, Dominique; Auxepaules, Ludovic; Alonso, Mathilde

    2013-01-01

    This paper presents Diagram, a learning environment for object-oriented modelling (OOM) with UML class diagrams. Diagram an open environment, in which the teacher can add new exercises without constraints on the vocabulary or the size of the diagram. The interface includes methodological help, encourages self-correcting and self-monitoring, and…

  16. Diagram, a Learning Environment for Initiation to Object-Oriented Modeling with UML Class Diagrams

    Science.gov (United States)

    Py, Dominique; Auxepaules, Ludovic; Alonso, Mathilde

    2013-01-01

    This paper presents Diagram, a learning environment for object-oriented modelling (OOM) with UML class diagrams. Diagram an open environment, in which the teacher can add new exercises without constraints on the vocabulary or the size of the diagram. The interface includes methodological help, encourages self-correcting and self-monitoring, and…

  17. Origin and use of crystallization phase diagrams.

    Science.gov (United States)

    Rupp, Bernhard

    2015-03-01

    Crystallization phase diagrams are frequently used to conceptualize the phase relations and also the processes taking place during the crystallization of macromolecules. While a great deal of freedom is given in crystallization phase diagrams owing to a lack of specific knowledge about the actual phase boundaries and phase equilibria, crucial fundamental features of phase diagrams can be derived from thermodynamic first principles. Consequently, there are limits to what can be reasonably displayed in a phase diagram, and imagination may start to conflict with thermodynamic realities. Here, the commonly used `crystallization phase diagrams' are derived from thermodynamic excess properties and their limitations and appropriate use is discussed.

  18. Using Affinity Diagrams to Evaluate Interactive Prototypes

    DEFF Research Database (Denmark)

    Lucero, Andrés

    2015-01-01

    Affinity diagramming is a technique used to externalize, make sense of, and organize large amounts of unstructured, far-ranging, and seemingly dissimilar qualitative data. HCI and interaction design practitioners have adopted and used affinity diagrams for different purposes. This paper discusses...... our particular use of affinity diagramming in prototype evaluations. We reflect on a decade’s experience using affinity diagramming across a number of projects, both in industry and academia. Our affinity diagramming process in interaction design has been tailored and consists of four stages: creating...

  19. Diagram Size vs. Layout Flaws: Understanding Quality Factors of UML Diagrams

    DEFF Research Database (Denmark)

    Störrle, Harald

    2016-01-01

    , though, is our third goal of extending our analysis aspects of diagram quality. Method: We improve our definition of diagram size and add a (provisional) definition of diagram quality as the number of topographic layout flaws. We apply these metrics on 60 diagrams of the five most commonly used types...... of UML diagram. We carefully analyze the structure of our diagram samples to ensure representativeness. We correlate diagram size and layout quality with modeler performance data obtained in previous experiments. The data set is the largest of its kind (n-156). Results: We replicate earlier findings......, and extend them to two new diagram types. We provide an improved definition of diagram size, and provide a definition of topographic layout quality, which is one more step towards a comprehensive definition of diagram quality as such. Both metrics are shown to be objectively applicable. We quantify...

  20. Indian Ocean margins

    Digital Repository Service at National Institute of Oceanography (India)

    Naqvi, S.W.A.

    The most important biogeochemical transformations and boundary exchanges in the Indian Ocean seem to occur in the northern region, where the processes originating at the land-ocean boundary extend far beyond the continental margins. Exchanges across...

  1. Learning unbelievable marginal probabilities

    CERN Document Server

    Pitkow, Xaq; Miller, Ken D

    2011-01-01

    Loopy belief propagation performs approximate inference on graphical models with loops. One might hope to compensate for the approximation by adjusting model parameters. Learning algorithms for this purpose have been explored previously, and the claim has been made that every set of locally consistent marginals can arise from belief propagation run on a graphical model. On the contrary, here we show that many probability distributions have marginals that cannot be reached by belief propagation using any set of model parameters or any learning algorithm. We call such marginals `unbelievable.' This problem occurs whenever the Hessian of the Bethe free energy is not positive-definite at the target marginals. All learning algorithms for belief propagation necessarily fail in these cases, producing beliefs or sets of beliefs that may even be worse than the pre-learning approximation. We then show that averaging inaccurate beliefs, each obtained from belief propagation using model parameters perturbed about some le...

  2. Non-linear stability of high-speed bogies and their safety margin strategy%高速转向架非线性稳定性及安全裕度对策

    Institute of Scientific and Technical Information of China (English)

    朴明伟; 梁树林; 孔维刚; 兆文忠

    2011-01-01

    In order to satisfy the safety stability-margin requirements of new-generation high-speed bogies, based on the exploration of bogie frame acceleration alarm, the soft constraint solutions for yawing and their technical implementation steps were presented. The running stability analysis is a synthetical evaluation including the critical velocity and dynamical behavior assessment. The critical velocities depend on the W/R ( wheel/rail) matching features, and are influenced remarkably by the non-linear variation of both W/R contact and bogies themselves. The dynamical behavior evaluations are implemented according to the evaluation on the safety index of bogie's frame lateral acceleration, etc. Due to the anti-hunting dampers having the high-frequency blowing-off mechanism, the safety limits may still be reached or exceeded by the dynamical behaviors of trailer bogies in spite of the small amplitude of wheelset hunting under the subcritical bifurcation. The lateral acceleration frequency response analysis of bogie's frame show that the hunting oscillation is the main harmonic component in the vibration frequency responses, which can be controlled by the soft constraint solutions for yawing.%为了满足新一代高速转向架的安全稳定性裕度要求,在构架振动报警原因分析的基础上,提出了抗蛇行减振器软约束技术对策.运行稳定性分析是指包括临界速度和动态行为在内的综合评价.临界速度取决于轮轨匹配特征,其对轮轨接触及转向架的非线性变化也将产生非常敏感的影响.动态行为评价是按照相关标准规范要求进行的构架横向加速度等安全指标评价.尽管在超临界分叉下轮对小幅值蛇行,但是由于抗蛇行减振器具有高频卸荷机制,拖车转向架动态行为也有可能达到或超过安全限制.构架横向加速度频响对比分析表明:转向架蛇行振荡是其振动频响的主要谐振成份,可以采用抗蛇行减振器软约束方式加以控制.

  3. Grid diagrams and Khovanov homology

    DEFF Research Database (Denmark)

    Droz, Jean-Marie; Wagner, Emmanuel

    2009-01-01

    We explain how to compute the Jones polynomial of a link from one of its grid diagrams and we observe a connection between Bigelow’s homological definition of the Jones polynomial and Kauffman’s definition of the Jones polynomial. Consequently, we prove that the Maslov grading on the Seidel......–Smith symplectic link invariant coincides with the difference between the homological grading on Khovanov homology and the Jones grading on Khovanov homology. We give some evidence for the truth of the Seidel–Smith conjecture....

  4. Phase Diagrams of Nuclear Pasta

    Science.gov (United States)

    Caplan, Matthew; Horowitz, Chuck; Berry, Don; da Silva Schneider, Andre

    2016-03-01

    In the inner crust of neutrons stars, where matter is near the saturation density, protons and neutrons arrange themselves into complex structures called nuclear pasta. Early theoretical work predicted a simple graduated hierarchy of pasta phases, consisting of spheres, cylinders, slabs, and uniform matter with voids. Previous work has simulated these phases with a simple classical model and has shown that the formation of these structures is dependent on the temperature, density, and proton fraction. However, previous work only studied a limited range of these parameters due to computational limitations. Thanks to recent advances in computing it is now possible to survey the structure of nuclear pasta for a larger range of parameters. By simulating nuclear pasta with constant temperature and proton fraction in an expanding simulation volume we are able to study the phase transitions in nuclear pasta, and thus produce a set of phase diagrams. We report on these phase diagrams as well as newly identified phases of nuclear pasta and discuss their implications for neutron star observables.

  5. Asteroseismology Across the HR Diagram

    Science.gov (United States)

    Thompson, M. J.; Cunha, M. S.; Monteiro, M. J. P. F. G.

    2003-05-01

    Ground-based observations have detected solar-like oscillations on Sun-like stars, and diagnostics similar to those used in helioseismology are now being used to test and constrain the physics and evolutionary state of these stars. Multi-mode oscillations are being observed in an abundance of other stars, including slowly pulsating B stars (SPB stars), delta-Scuti stars, Ap stars and the pulsating white dwarfs. New classes of pulsators continue to be discovered across the Herzsprung-Russell diagram. Yet the chances still to be faced to make asteroseismology across the HR diagram a reality are formidable. Observation, data analysis and theory all pose hard problems to be overcome. This book, reflecting the goal of the meeting, aims to facilitate a cross-fertilisation of ideas and approaches between fields covering different pulsators and with different areas of expertise. The book successfully covers most known types of pulsators, reflecting a highly productive and far reaching interchange of ideas which we believe is conveyed by the papers and posters published, making it a reference for researchers and postgraduate students working on stellar structure and evolution. Link: http://www.wkap.nl/prod/b/1-4020-1173-3

  6. Zone diagrams in compact subsets of uniformly convex normed spaces

    CERN Document Server

    Kopecká, Eva; Reich, Simeon

    2010-01-01

    A zone diagram is a relatively new concept which has emerged in computational geometry and is related to Voronoi diagrams. Formally, it is a fixed point of a certain mapping, and neither its uniqueness nor its existence are obvious in advance. It has been studied by several authors, starting with T. Asano, J. Matousek and T. Tokuyama, who considered the Euclidean plane with singleton sites, and proved the existence and uniqueness of zone diagrams there. In the present paper we prove the existence of zone diagrams with respect to finitely many pairwise disjoint compact sites contained in a compact and convex subset of a uniformly convex normed space. The proof is based on the Schauder fixed point theorem, the Curtis-Schori theorem regarding the Hilbert cube, and on recent results concerning the characterization of Voronoi cells as a collection of line segments and their geometric stability with respect to small changes of the corresponding sites. Along the way we obtain the continuity of the Dom mapping as wel...

  7. Geochemical discrimination of siliciclastic sediments from active and passive margin settings

    Science.gov (United States)

    Verma, Surendra P.; Armstrong-Altrin, John S.

    2016-03-01

    Discrimination of active and passive margins is important from both academic and economic aspects. This can only be successfully achieved, however, if there are major compositional differences among sediments derived from different continental margins. A worldwide database of active and passive margin settings was established from published major and trace element geochemical data of Neogene to Quaternary siliciclastic sediments. These data were used to evaluate the performance of existing discrimination diagrams, which were shown to work unsatisfactorily with success values of mostly between 0% and 30%. Because these diagrams were not based on a statistically coherent methodology, we proposed two new discriminant functions from linear discriminant analysis of multinormally distributed isometric log-transformed ratios of major and combined major and trace elements. These new diagrams showed very high percent success values of about 87%-97% and 84%-86% for the active and passive margins, respectively, for the original database. Excellent performance of the multidimensional diagrams and related discriminant functions was confirmed from 11 test studies involving Quaternary to Holocene siliciclastic sediments from known tectonic margins. The expected result of an active or passive margin was obtained, with most samples plotting correctly in the respective field.

  8. Continuation of point clouds via persistence diagrams

    Science.gov (United States)

    Gameiro, Marcio; Hiraoka, Yasuaki; Obayashi, Ippei

    2016-11-01

    In this paper, we present a mathematical and algorithmic framework for the continuation of point clouds by persistence diagrams. A key property used in the method is that the persistence map, which assigns a persistence diagram to a point cloud, is differentiable. This allows us to apply the Newton-Raphson continuation method in this setting. Given an original point cloud P, its persistence diagram D, and a target persistence diagram D‧, we gradually move from D to D‧, by successively computing intermediate point clouds until we finally find a point cloud P‧ having D‧ as its persistence diagram. Our method can be applied to a wide variety of situations in topological data analysis where it is necessary to solve an inverse problem, from persistence diagrams to point cloud data.

  9. Mathematical review on source-type diagrams

    Science.gov (United States)

    Aso, Naofumi; Ohta, Kazuaki; Ide, Satoshi

    2016-03-01

    A source-type diagram is a visualization tool used to display earthquake sources, including double-couples, compensated linear vector dipoles, and isotropic deformation. Together with recent observations of non-double-couple events in a variety of tectonic settings, it is important to be able to recognize the source type intuitively from a representative diagram. Since previous works have proposed diagrams created using a range of projections, we review these diagrams in the framework of the moment tensor eigenvalue space. For further applications, we also provide complete formulas for conversion between moment tensor representation and the coordinate system of each diagram style. Using both a global catalog and synthetic data, we discuss differences between types of diagrams and the relative effectiveness of each.

  10. Retrospect and Prospect of the Influence Diagram

    Institute of Scientific and Technical Information of China (English)

    LiuYanqiong; ShenYongping; ChenYingwu

    2005-01-01

    The evaluation algorithm and the application of the influence diagram were surveyed, which argues that to construct an explicit,compact and objective influence diagram is of the most importance. There are two suggested ways for realization of the influence diagram: introducing the achievements of the modern psychology, cognitive science, behavior science, and so on to represent and solve uncertainty to build a well-constructed influence diagram; based on the observed data to build an influence diagram. Also, the limitations of the influence diagram were analyzed, such as that it cannot deal with asynunetric problems efficiently, cannot picture dynamic problems,cannot model the problems with a limitless horizon, and ther is no highly efficient algorithm. And some potential methods to overcome these limitations were pointed out.

  11. Mapping the QCD phase diagram

    CERN Document Server

    Rajagopal, K

    1999-01-01

    The QCD vacuum in which we live, which has the familiar hadrons as its excitations, is but one phase of QCD, and far from the simplest one at that. One way to better understand this phase and the nonperturbative dynamics of QCD more generally is to study other phases and the transitions between phases. We are engaged in a voyage of exploration, mapping the QCD phase diagram as a function of temperature T and baryon number chemical potential mu . Because of asymptotic freedom, the high temperature and high baryon density phases of QCD are more simply and more appropriately described in terms of quarks and gluons as degrees of freedom, rather than hadrons. The chiral symmetry breaking condensate which characterizes the vacuum phase melts away. At high densities, quarks form Cooper pairs and new condensates develop. The formation of such superconducting phases requires only weak attractive interactions; these phases may nevertheless break chiral symmetry and have excitations which are indistinguishable from thos...

  12. Gravity On-shell Diagrams

    CERN Document Server

    Herrmann, Enrico

    2016-01-01

    We study on-shell diagrams for gravity theories with any number of supersymmetries and find a compact Grassmannian formula in terms of edge variables of the graphs. Unlike in gauge theory where the analogous form involves only $\\dlog$-factors, in gravity there is a non-trivial numerator as well as higher degree poles in the edge variables. Based on the structure of the Grassmannian formula for $\\N=8$ supergravity we conjecture that gravity loop amplitudes also possess similar properties. In particular, we find that there are only logarithmic singularities on cuts with finite loop momentum, poles at infinity are present and loop amplitudes show special behavior on certain collinear cuts. We demonstrate on 1-loop and 2-loop examples that the behavior on collinear cuts is a highly non-trivial property which requires cancellations between all terms contributing to the amplitude.

  13. Gravity on-shell diagrams

    Energy Technology Data Exchange (ETDEWEB)

    Herrmann, Enrico [Walter Burke Institute for Theoretical Physics, California Institute of Technology,Pasadena, CA 91125 (United States); Trnka, Jaroslav [Center for Quantum Mathematics and Physics (QMAP),Department of Physics, University of California,Davis, CA 95616 (United States)

    2016-11-22

    We study on-shell diagrams for gravity theories with any number of supersymmetries and find a compact Grassmannian formula in terms of edge variables of the graphs. Unlike in gauge theory where the analogous form involves only dlog-factors, in gravity there is a non-trivial numerator as well as higher degree poles in the edge variables. Based on the structure of the Grassmannian formula for N=8 supergravity we conjecture that gravity loop amplitudes also possess similar properties. In particular, we find that there are only logarithmic singularities on cuts with finite loop momentum and that poles at infinity are present, in complete agreement with the conjecture presented in http://dx.doi.org/10.1007/JHEP06(2015)202.

  14. Solving Limited Memory Influence Diagrams

    CERN Document Server

    Mauá, Denis Deratani; Zaffalon, Marco

    2011-01-01

    We present a new algorithm for exactly solving decision making problems represented as influence diagrams. We do not require the usual assumptions of no forgetting and regularity; this allows us to solve problems with simultaneous decisions and limited information. The algorithm is empirically shown to outperform a state-of-the-art algorithm on randomly generated problems of up to 150 variables and $10^{64}$ solutions. We show that the problem is NP-hard even if the underlying graph structure of the problem has small treewidth and the variables take on a bounded number of states, but that a fully polynomial time approximation scheme exists for these cases. Moreover, we show that the bound on the number of states is a necessary condition for any efficient approximation scheme.

  15. Stereo 3D spatial phase diagrams

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Jinwu, E-mail: kangjw@tsinghua.edu.cn; Liu, Baicheng, E-mail: liubc@tsinghua.edu.cn

    2016-07-15

    Phase diagrams serve as the fundamental guidance in materials science and engineering. Binary P-T-X (pressure–temperature–composition) and multi-component phase diagrams are of complex spatial geometry, which brings difficulty for understanding. The authors constructed 3D stereo binary P-T-X, typical ternary and some quaternary phase diagrams. A phase diagram construction algorithm based on the calculated phase reaction data in PandaT was developed. And the 3D stereo phase diagram of Al-Cu-Mg ternary system is presented. These phase diagrams can be illustrated by wireframe, surface, solid or their mixture, isotherms and isopleths can be generated. All of these can be displayed by the three typical display ways: electronic shutter, polarization and anaglyph (for example red-cyan glasses). Especially, they can be printed out with 3D stereo effect on paper, and watched by the aid of anaglyph glasses, which makes 3D stereo book of phase diagrams come to reality. Compared with the traditional illustration way, the front of phase diagrams protrude from the screen and the back stretches far behind of the screen under 3D stereo display, the spatial structure can be clearly and immediately perceived. These 3D stereo phase diagrams are useful in teaching and research. - Highlights: • Stereo 3D phase diagram database was constructed, including binary P-T-X, ternary, some quaternary and real ternary systems. • The phase diagrams can be watched by active shutter or polarized or anaglyph glasses. • The print phase diagrams retains 3D stereo effect which can be achieved by the aid of anaglyph glasses.

  16. Process Flow Diagrams for Training and Operations

    Science.gov (United States)

    Venter, Jacobus

    This paper focuses on the use of process flow diagrams for training first responders who execute search and seizure warrants at electronic crime scenes. A generic process flow framework is presented, and the design goals and layout characteristics of process flow diagrams are discussed. An evaluation of the process flow diagrams used in training courses indicates that they are beneficial to first responders performing searches and seizures, and they speed up investigations, including those conducted by experienced personnel.

  17. The spectroscopic Hertzsprung-Russell diagram

    CERN Document Server

    Langer, N

    2014-01-01

    The Hertzsprung-Russell diagram is an essential diagnostic diagram for stellar structure and evolution, which has now been in use for more than 100 years. Our spectroscopic Hertzsprung-Russell (sHR) diagram shows the inverse of the flux-mean gravity versus the effective temperature. Observed stars whose spectra have been quantitatively analyzed can be entered in this diagram without the knowledge of the stellar distance or absolute brightness. Observed stars can be as conveniently compared to stellar evolution calculations in the sHR diagram as in the Hertzsprung-Russell diagram. However, at the same time, our ordinate is proportional to the stellar mass-to-luminosity ratio, which can thus be directly determined. For intermediate- and low-mass star evolution at constant mass, we show that the shape of an evolutionary track in the sHR diagram is identical to that in the Hertzsprung-Russell diagram. We also demonstrate that for hot stars, their stellar Eddington factor can be directly read off the sHR diagram. ...

  18. Hofstadter Butterfly Diagram in Noncommutative Space

    CERN Document Server

    Takahashi, H; Takahashi, Hidenori; Yamanaka, Masanori

    2006-01-01

    We study an energy spectrum of electron moving under the constant magnetic field in two dimensional noncommutative space. It take place with the gauge invariant way. The Hofstadter butterfly diagram of the noncommutative space is calculated in terms of the lattice model which is derived by the Bopp's shift for space and by the Peierls substitution for external magnetic field. We also find the fractal structure in new diagram. Although the global features of the new diagram are similar to the diagram of the commutative space, the detail structure is different from it.

  19. Magnetic phase diagrams of classical triangular and kagome antiferromagnets

    Energy Technology Data Exchange (ETDEWEB)

    Gvozdikova, M V [Department of Physics, Kharkov National University, 61077 Kharkov (Ukraine); Melchy, P-E; Zhitomirsky, M E, E-mail: mike.zhitomirsky@cea.fr [Service de Physique Statistique, Magnetisme et Supraconductivite, UMR-E9001 CEA-INAC/UJF, 17 rue des Martyrs, 38054 Grenoble (France)

    2011-04-27

    We investigate the effect of geometrical frustration on the H-T phase diagrams of the classical Heisenberg antiferromagnets on triangular and kagome lattices. The phase diagrams for the two models are obtained from large-scale Monte Carlo simulations. For the kagome antiferromagnet, thermal fluctuations are unable to lift degeneracy completely and stabilize translationally disordered multipolar phases. We find a substantial difference in the temperature scales of the order by disorder effect related to different degeneracy of the low- and the high-field classical ground states in the kagome antiferromagnet. In the low-field regime, the Kosterlitz-Thouless transition into a spin-nematic phase is produced by unbinding of half-quantum vortices.

  20. Magnetic phase diagrams of classical triangular and kagome antiferromagnets.

    Science.gov (United States)

    Gvozdikova, M V; Melchy, P-E; Zhitomirsky, M E

    2011-04-27

    We investigate the effect of geometrical frustration on the H-T phase diagrams of the classical Heisenberg antiferromagnets on triangular and kagome lattices. The phase diagrams for the two models are obtained from large-scale Monte Carlo simulations. For the kagome antiferromagnet, thermal fluctuations are unable to lift degeneracy completely and stabilize translationally disordered multipolar phases. We find a substantial difference in the temperature scales of the order by disorder effect related to different degeneracy of the low- and the high-field classical ground states in the kagome antiferromagnet. In the low-field regime, the Kosterlitz-Thouless transition into a spin-nematic phase is produced by unbinding of half-quantum vortices.

  1. Size Dependent Phase Diagrams of Nickel-Carbon Nanoparticles.

    Science.gov (United States)

    Magnin, Y; Zappelli, A; Amara, H; Ducastelle, F; Bichara, C

    2015-11-13

    The carbon rich phase diagrams of nickel-carbon nanoparticles, relevant to catalysis and catalytic chemical vapor deposition synthesis of carbon nanotubes, are calculated for system sizes up to about 3 nm (807 Ni atoms). A tight binding model for interatomic interactions drives the grand canonical Monte Carlo simulations used to locate solid, core shell and liquid stability domains, as a function of size, temperature, and carbon chemical potential or concentration. Melting is favored by carbon incorporation from the nanoparticle surface, resulting in a strong relative lowering of the eutectic temperature and a phase diagram topology different from the bulk one. This should lead to a better understanding of the nanotube growth mechanisms.

  2. Masculinity at the margins

    DEFF Research Database (Denmark)

    Jensen, Sune Qvotrup

    2010-01-01

    This article analyses how young marginalized ethnic minority men in Denmark react to the othering they are subject to in the media as well as in the social arenas of every day life. The article is based on theoretically informed ethnographic fieldwork among such young men as well as interviews an...

  3. From Borders to Margins

    DEFF Research Database (Denmark)

    Parker, Noel

    2009-01-01

    upon Deleuze's philosophy to set out an ontology in which the continual reformulation of entities in play in ‘post-international' society can be grasped.  This entails a strategic shift from speaking about the ‘borders' between sovereign states to referring instead to the ‘margins' between a plethora...

  4. Marginally Deformed Starobinsky Gravity

    DEFF Research Database (Denmark)

    Codello, A.; Joergensen, J.; Sannino, Francesco

    2015-01-01

    We show that quantum-induced marginal deformations of the Starobinsky gravitational action of the form $R^{2(1 -\\alpha)}$, with $R$ the Ricci scalar and $\\alpha$ a positive parameter, smaller than one half, can account for the recent experimental observations by BICEP2 of primordial tensor modes....

  5. "We call ourselves marginalized"

    DEFF Research Database (Denmark)

    Jørgensen, Nanna Jordt

    2014-01-01

    In recent decades, indigenous knowledge has been added to the environmental education agenda in an attempt to address the marginalization of non-western perspectives. While these efforts are necessary, the debate is often framed in terms of a discourse of victimization that overlooks the agency o...

  6. Stage line diagram: An age-conditional reference diagram for tracking development

    NARCIS (Netherlands)

    Buuren, S. van; Ooms, J.C.L.

    2009-01-01

    This paper presents a method for calculating stage line diagrams, a novel type of reference diagram useful for tracking developmental processes over time. Potential fields of applications include: dentistry (tooth eruption), oncology (tumor grading, cancer staging), virology (HIV infection and

  7. Stage line diagram: an age-conditional reference diagram for tracking development.

    NARCIS (Netherlands)

    Van Buuren, S.; Ooms, J.C.L.

    2009-01-01

    This paper presents a method for calculating stage line diagrams, a novel type of reference diagram useful for tracking developmental processes over time. Potential fields of applications include: dentistry (tooth eruption), oncology (tumor grading, cancer staging), virology (HIV infection and

  8. Lubrication modes and the IRG transition diagram

    NARCIS (Netherlands)

    Schipper, D.J.; Gee, de A.W.J.

    1995-01-01

    The relationship between a Lubrication Mode Diagram (LMD) for concentrated contacts (LCC's) and the IRG transition diagram has been studied. In addition, scuffing results, obtained by the IRG (International Research Group) have been analysed, as well as the results of scuffing tests performed by dif

  9. Comprehending process diagrams in biology education

    NARCIS (Netherlands)

    Kragten, M.

    2015-01-01

    Students in secondary Science education seem to have difficulties with comprehending diagrams. Process diagrams are an important type of representation in Biology for explaining processes like protein synthesis, compound cycles, etc. In this thesis, we aimed at getting deeper insight into students’

  10. Ferroelectric phase diagram of PVDF:PMMA

    NARCIS (Netherlands)

    Li, M.; Stingelin, N.; Michels, J.J.; Spijkman, M.-J.; Asadi, K.; Feldman, K.; Blom, P.W.M.; Leeuw, D.M. de

    2012-01-01

    We have investigated the ferroelectric phase diagram of poly(vinylidene fluoride) (PVDF) and poly(methyl methacrylate) (PMMA). The binary nonequilibrium temperature composition diagram was determined and melting of α- and β-phase PVDF was identified. Ferroelectric β-PVDF:PMMA blend films were made b

  11. Ferroelectric Phase Diagram of PVDF : PMMA

    NARCIS (Netherlands)

    Li, Mengyuan; Stingelin, Natalie; Michels, Jasper J.; Spijkman, Mark-Jan; Asadi, Kamal; Feldman, Kirill; Blom, Paul W. M.; de Leeuw, Dago M.

    2012-01-01

    We have investigated the ferroelectric phase diagram of poly(vinylidene fluoride) (PVDF) and poly(methyl methacrylate) (PMMA). The binary nonequilibrium temperature composition diagram was determined and melting of alpha- and beta-phase PVDF was identified. Ferroelectric beta-PVDF:PMMA blend films w

  12. Automatically extracting class diagrams from spreadsheets

    NARCIS (Netherlands)

    Hermans, F.; Pinzger, M.; Van Deursen, A.

    2010-01-01

    The use of spreadsheets to capture information is widespread in industry. Spreadsheets can thus be a wealthy source of domain information. We propose to automatically extract this information and transform it into class diagrams. The resulting class diagram can be used by software engineers to under

  13. Structural Controllability and Observability in Influence Diagrams

    OpenAIRE

    Chan, Brian Y.; Shachter, Ross D.

    2013-01-01

    Influence diagram is a graphical representation of belief networks with uncertainty. This article studies the structural properties of a probabilistic model in an influence diagram. In particular, structural controllability theorems and structural observability theorems are developed and algorithms are formulated. Controllability and observability are fundamental concepts in dynamic systems (Luenberger 1979). Controllability corresponds to the ability to control a system while observability a...

  14. Automatic fitting procedure for the fundamental diagram

    NARCIS (Netherlands)

    Knoop, V.L.; Daamen, W.

    2014-01-01

    The fundamental diagram of a road, including free flow capacity and queue discharge rate, is very important for traffic engineering purposes. In the real word, most traffic measurements come from stationary loop detectors. This paper proposes a method to fit Wu’s fundamental diagram to loop detector

  15. Resummation of Cactus Diagrams in Lattice QCD

    CERN Document Server

    Panagopoulos, H

    1998-01-01

    We show how to perform a resummation, to all orders in perturbation theory, of a certain class of gauge invariant diagrams in Lattice QCD. These diagrams are often largely responsible for lattice artifacts. Our resummation leads to an improved perturbative expansion. Applied to a number of cases of interest, this expansion yields results remarkably close to corresponding nonperturbative estimates.

  16. Statistical Mechanics of Soft Margin Classifiers

    OpenAIRE

    Risau-Gusman, Sebastian; Gordon, Mirta B.

    2001-01-01

    We study the typical learning properties of the recently introduced Soft Margin Classifiers (SMCs), learning realizable and unrealizable tasks, with the tools of Statistical Mechanics. We derive analytically the behaviour of the learning curves in the regime of very large training sets. We obtain exponential and power laws for the decay of the generalization error towards the asymptotic value, depending on the task and on general characteristics of the distribution of stabilities of the patte...

  17. Persistence Diagrams and the Heat Equation Homotopy

    CERN Document Server

    Fasy, Brittany Terese

    2010-01-01

    Persistence homology is a tool used to measure topological features that are present in data sets and functions. Persistence pairs births and deaths of these features as we iterate through the sublevel sets of the data or function of interest. I am concerned with using persistence to characterize the difference between two functions f, g : M -> R, where M is a topological space. Furthermore, I formulate a homotopy from g to f by applying the heat equation to the difference function g-f. By stacking the persistence diagrams associated with this homotopy, we create a vineyard of curves that connect the points in the diagram for f with the points in the diagram for g. I look at the diagrams where M is a square, a sphere, a torus, and a Klein bottle. Looking at these four topologies, we notice trends (and differences) as the persistence diagrams change with respect to time.

  18. Free-Body Diagrams: Necessary or Sufficient?

    Science.gov (United States)

    Rosengrant, David; Van Heuvelen, Alan; Etkina, Eugenia

    2005-09-01

    The Rutgers PAER group is working to help students develop various scientific abilities. One of the abilities is to create, understand and learn to use for qualitative reasoning and problem solving different representations of physical processes such as pictorial representations, motion diagrams, free-body diagrams, and energy bar charts. Physics education literature indicates that using multiple representations is beneficial for student understanding of physics ideas and for problem solving. We developed a special approach to construct and utilize free-body diagrams for representing physical phenomena and for problem solving. We will examine whether students draw free-body diagrams in solving problems when they know they will not receive credit for it; the consistency of their use in different conceptual areas; and if students who use free-body diagrams while solving problems in different areas of physics are more successful then those who do not.

  19. Phase diagram of elastic spheres.

    Science.gov (United States)

    Athanasopoulou, L; Ziherl, P

    2017-02-15

    Experiments show that polymeric nanoparticles often self-assemble into several non-close-packed lattices in addition to the face-centered cubic lattice. Here, we explore theoretically the possibility that the observed phase sequences may be associated with the softness of the particles, which are modeled as elastic spheres interacting upon contact. The spheres are described by two finite-deformation theories of elasticity, the modified Saint-Venant-Kirchhoff model and the neo-Hookean model. We determine the range of indentations where the repulsion between the spheres is pairwise additive and agrees with the Hertz theory. By computing the elastic energies of nine trial crystal lattices at densities far beyond the Hertzian range, we construct the phase diagram and find the face- and body-centered cubic lattices as well as the A15 lattice and the simple hexagonal lattice, with the last two being stable at large densities where the spheres are completely faceted. These results are qualitatively consistent with observations, suggesting that deformability may indeed be viewed as a generic property that determines the phase behavior in nanocolloidal suspensions.

  20. Masculinity at the margins

    DEFF Research Database (Denmark)

    Jensen, Sune Qvotrup

    2010-01-01

    of critique although in a masculinist way. These reactions to othering represent a challenge to researchers interested in intersectionality and gender, because gender is reproduced as a hierarchical form of social differentiation at the same time as racism is both reproduced and resisted.......This article analyses how young marginalized ethnic minority men in Denmark react to the othering they are subject to in the media as well as in the social arenas of every day life. The article is based on theoretically informed ethnographic fieldwork among such young men as well as interviews...... and other types of material. Taking the concepts of othering, intersectionality and marginality as point of departure the article analyses how these young men experience othering and how they react to it. One type of reaction, described as stylization, relies on accentuating the latently positive symbolic...

  1. The Seismicity of Two Hyperextended Margins

    Science.gov (United States)

    Redfield, Tim; Terje Osmundsen, Per

    2013-04-01

    A seismic belt marks the outermost edge of Scandinavia's proximal margin, inboard of and roughly parallel to the Taper Break. A similar near- to onshore seismic belt runs along its inner edge, roughly parallel to and outboard of the asymmetric, seaward-facing escarpment. The belts converge at both the northern and southern ends of Scandinavia, where crustal taper is sharp and the proximal margin is narrow. Very few seismic events have been recorded on the intervening, gently-tapering Trøndelag Platform. Norway's distribution of seismicity is systematically ordered with respect to 1) the structural templates of high-beta extension that shaped the thinning gradient during Late Jurassic or Early Cretaceous time, and 2) the topographically resurgent Cretaceous-Cenozoic "accommodation phase" family of escarpments that approximate the innermost limit of crustal thinning [See Redfield and Osmundsen (2012) for diagrams, definitions, discussion, and supporting citations.] Landwards from the belt of earthquake epicenters that mark the Taper Break the crust consistently thickens, and large fault arrays tend to sole out at mid crustal levels. Towards the sea the crystalline continental crust is hyperextended, pervasively faulted, and generally very thin. Also, faulting and serpentinization may have affected the uppermost parts of the distal margin's lithospheric mantle. Such contrasting structural conditions may generate a contrasting stiffness: for a given stress, more strain can be accommodated in the distal margin than in the less faulted proximal margin. By way of comparison, inboard of the Taper Break on the gently-tapered Trøndelag Platform, faulting was not penetrative. There, similar structural conditions prevail and proximal margin seismicity is negligible. Because stress concentration can occur where material properties undergo significant contrast, the necking zone may constitute a natural localization point for post-thinning phase earthquakes. In Scandinavia

  2. Equilibrium Distributions and the Nanostructure Diagram for Epitaxial Quantum Dots

    Energy Technology Data Exchange (ETDEWEB)

    Rudd, R E; Briggs, G D; Sutton, A P; Medeiros-Ribeiro, G; Williams, R S

    2006-05-01

    We present in detail a thermodynamic equilibrium model for the growth of nanostructures on semiconductor substrates in heteroepitaxy and its application to germanium deposition on silicon. Some results of this model have been published previously, but the details of the formulation of the model are given here for the first time. The model allows the computation of the shape and size distributions of the surface nanostructures, as well as other properties of the system. We discuss the results of the model, and their incorporation into a nanostructure diagram that summarizes the relative stability of domes and pyramids in the bimodal size distributions.

  3. Faceting diagram for sticky steps

    Directory of Open Access Journals (Sweden)

    Noriko Akutsu

    2016-03-01

    Full Text Available Faceting diagrams for the step-faceting zone, the step droplet zone, and the Gruber-Mullins-Pokrovsky-Talapov (GMPT zone for a crystal surface are obtained by using the density matrix renormalization group method to calculate the surface tension. The model based on these calculations is the restricted solid-on-solid (RSOS model with a point-contact-type step-step attraction (p-RSOS model on a square lattice. The point-contact-type step-step attraction represents the energy gain obtained by forming a bonding state with orbital overlap at the meeting point of the neighboring steps. In the step-faceting zone, disconnectedness in the surface tension leads to the formation of a faceted macrostep on a vicinal surface at equilibrium. The disconnectedness in the surface tension also causes the first-order shape transition for the equilibrium shape of a crystal droplet. The lower zone boundary line (ZBL, which separates the step-faceting zone and the step droplet zone, is obtained by the condition γ 1 = lim n → ∞ γ n / n , where γn is the step tension of the n-th merged step. The upper ZBL, which separates the GMPT zone and the step droplet zone, is obtained by the condition Aq,eff = 0 and Bq,eff = 0, where Aq,eff and Bq,eff represent the coefficients for the | q → | 2 term and the | q → | 3 term, respectively, in the | q → | -expanded form of the surface free energy f eff ( q → . Here, q → is the surface gradient relative to the (111 surface. The reason why the vicinal surface inclined in the 〈101〉 direction does not exhibit step-faceting is explained in terms of the one-dimensional spinless quasi-impenetrable attractive bosons at absolute zero.

  4. The phase diagram of water at negative pressures: virtual ices.

    Science.gov (United States)

    Conde, M M; Vega, C; Tribello, G A; Slater, B

    2009-07-21

    The phase diagram of water at negative pressures as obtained from computer simulations for two models of water, TIP4P/2005 and TIP5P is presented. Several solid structures with lower densities than ice Ih, so-called virtual ices, were considered as possible candidates to occupy the negative pressure region of the phase diagram of water. In particular the empty hydrate structures sI, sII, and sH and another, recently proposed, low-density ice structure. The relative stabilities of these structures at 0 K was determined using empirical water potentials and density functional theory calculations. By performing free energy calculations and Gibbs-Duhem integration the phase diagram of TIP4P/2005 was determined at negative pressures. The empty hydrates sII and sH appear to be the stable solid phases of water at negative pressures. The phase boundary between ice Ih and sII clathrate occurs at moderate negative pressures, while at large negative pressures sH becomes the most stable phase. This behavior is in reasonable agreement with what is observed in density functional theory calculations.

  5. PROCESS DIAGRAMS FOR INSTALLATION OF DRIVEN PILES IN PENETRATED WELLS

    Directory of Open Access Journals (Sweden)

    Kovalev Vladimir Aleksandrovich

    2017-03-01

    Full Text Available This article presents the main options of improved and newly devised designs and process diagrams for installation of foundations made of driven, or jack, piles in the penetrated wells with expanded shoe, mainly in weak wet (waterlogged and water-saturated soils. The article presents six options of process diagrams for installation of driven piles in penetrated wells, listing the main procedures: for well-compacted weak soils, for the case when the water ingress is excluded, for the case when it is necessary to increase the load-bearing capacity of pile's bearing face in the waterlogged soils, for the case when the load-bearing capacity of the pile shall be increased both for the end and for the sides, for the case when peat or other biogenous water-saturated soils are present at the bottom of the well, and for the case when there is no contracted zone nor practical possibility to ensure the stability of the walls. The proposed six options of process diagrams for installation of the driven piles in penetrated wells provide expansion of their area of application regarding the soil conditions, increase of load-bearing capacity, and possibility of using jack systems for driving the piles under conditions of dense urban development.

  6. The Dy-Zn phase diagram

    Science.gov (United States)

    Saccone, A.; Cardinale, A. M.; Delfino, S.; Ferro, R.

    2003-03-01

    The dysprosium-zinc phase diagram has been investigated over its entire composition range by using differential thermal analysis, (DTA) metallographic analysis, X-ray powder diffraction, and electron probe microanalysis (EPMA). Seven intermetallic phases have been found and their structures confirmed. DyZn, DyZn2, Dy13Zn58, and Dy2Zn17 melt congruently at 1095 °C, 1050 °C, 930 °C, and 930 °C, respectively. DyZn3, Dy3Zn11, and DyZn12 form through peritectic reactions at 895 °C, about 900 °C and 685 °C, respectively. Four eutectic reactions occur at 850 °C and 30.0 at pct Zn (between (Dy) and DyZn), 990 °C and 60.0 at pct Zn (between DyZn and DyZn2), 885 °C and 76.0 at pct Zn (between DyZn3 and Dy3Zn11), and 875 °C and 85.0 at pct Zn (involving Dy13Zn58 and Dy2Zn17). The Dy-rich end presents a catatectic equilibrium; a degenerate invariant effect has been found in the Zn-rich region. The phase equilibria of the Dy-Zn alloys are discussed and compared with those of the other known RE-Zn systems (RE=rare earth metal) in view of the regular change in the relative stabilities of the phases across the lanthanide series

  7. Breviz: Visualizing Spreadsheets using Dataflow Diagrams

    CERN Document Server

    Hermans, Felienne; van Deursen, Arie

    2011-01-01

    Spreadsheets are used extensively in industry, often for business critical purposes. In previous work we have analyzed the information needs of spreadsheet professionals and addressed their need for support with the transition of a spreadsheet to a colleague with the generation of data flow diagrams. In this paper we describe the application of these data flow diagrams for the purpose of understanding a spreadsheet with three example cases. We furthermore suggest an additional application of the data flow diagrams: the assessment of the quality of the spreadsheet's design.

  8. Modeling Workflow Using UML Activity Diagram

    Institute of Scientific and Technical Information of China (English)

    Wei Yinxing(韦银星); Zhang Shensheng

    2004-01-01

    An enterprise can improve its adaptability in the changing market by means of workflow technologies. In the build time, the main function of Workflow Management System (WFMS) is to model business process. Workflow model is an abstract representation of the real-world business process. The Unified Modeling Language (UML) activity diagram is an important visual process modeling language proposed by the Object Management Group (OMG). The novelty of this paper is representing workflow model by means of UML activity diagram. A translation from UML activity diagram to π-calculus is established. Using π-calculus, the deadlock property of workflow is analyzed.

  9. Between Analogue and Digital Diagrams

    Directory of Open Access Journals (Sweden)

    Zoltan Bun

    2012-10-01

    Full Text Available This essay is about the interstitial. About how the diagram, as a method of design, has lead fromthe analogue deconstruction of the eighties to the digital processes of the turn of the millennium.Specifically, the main topic of the text is the interpretation and the critique of folding (as a diagramin the beginning of the nineties. It is necessary then to unfold its relationship with immediatelypreceding and following architectural trends, that is to say we have to look both backwards andforwards by about a decade. The question is the context of folding, the exchange of the analogueworld for the digital. To understand the process it is easier to investigate from the fields of artand culture, rather than from the intentionally perplicated1 thoughts of Gilles Deleuze. Both fieldsare relevant here because they can similarly be used as the yardstick against which the era itselfit measured. The cultural scene of the eighties and nineties, including performing arts, movies,literature and philosophy, is a wide milieu of architecture. Architecture responds parallel to itsera; it reacts to it, and changes with it and within it. Architecture is a medium, it has always beena medium, yet the relations are transformed. That’s not to say that technical progress, for exampleusing CAD-software and CNC-s, has led to the digital thinking of certain movements ofarchitecture, (it is at most an indirect tool. But the ‘up-to-dateness’ of the discipline, however,a kind of non-servile reading of an ‘applied culture’ or ‘used philosophy’2 could be the key.(We might recall here, parenthetically, the fortunes of the artistic in contemporary mass society.The proliferation of museums, the magnification of the figure of the artist, the existence of amassive consumption of printed and televised artistic images, the widespread appetite for informationabout the arts, all reflect, of course, an increasingly leisured society, but also relateprecisely to the fact

  10. Covariant diagrams for one-loop matching

    CERN Document Server

    Zhang, Zhengkang

    2016-01-01

    We present a diagrammatic formulation of recently-revived covariant functional approaches to one-loop matching from an ultraviolet (UV) theory to a low-energy effective field theory. Various terms following from a covariant derivative expansion (CDE) are represented by diagrams which, unlike conventional Feynman diagrams, involve gauge-covariant quantities and are thus dubbed "covariant diagrams." The use of covariant diagrams helps organize and simplify one-loop matching calculations, which we illustrate with examples. Of particular interest is the derivation of UV model-independent universal results, which reduce matching calculations of specific UV models to applications of master formulas. We show how such derivation can be done in a more concise manner than the previous literature, and discuss how additional structures that are not directly captured by existing universal results, including mixed heavy-light loops, open covariant derivatives, and mixed statistics, can be easily accounted for.

  11. Relation among C-curve characterization diagrams

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    As three control points are fixed and the fourth control point varies, the planar cubic C-curve may take on a loop, a cusp, or zero to two inflection points, depending on the position of the moving point. The plane can, therefore, be partitioned into regions labelled according to the characterization of the curve when the fourth point is in each region. This partitioned plane is called a "characterization diagram". By moving one of the control points but fixing the rest, one can induce different characterization diagrams. In this paper, we investigate the relation among all different characterization diagrams of cubic C-curves based on the singularity conditions proposed by Yang and Wang (2004). We conclude that, no matter what the C-curve type is or which control point varies, the characterization diagrams can be obtained by cutting a common 3D characterization space with a corresponding plane.

  12. Revised Diagnostic Diagrams for Planetary Nebulae

    CERN Document Server

    Riesgo, H

    2006-01-01

    Diagnostic diagrams of electron density - excitation for a sample of 613 planetary nebulae are presented. The present extensive sample allows the definition of new statistical limits for the distribution of planetary nebulae in the log [Ha/[SII

  13. Covariant diagrams for one-loop matching

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zhengkang [Michigan Univ., Ann Arbor, MI (United States). Michigan Center for Theoretical Physics; Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2016-10-15

    We present a diagrammatic formulation of recently-revived covariant functional approaches to one-loop matching from an ultraviolet (UV) theory to a low-energy effective field theory. Various terms following from a covariant derivative expansion (CDE) are represented by diagrams which, unlike conventional Feynman diagrams, involve gaugecovariant quantities and are thus dubbed ''covariant diagrams.'' The use of covariant diagrams helps organize and simplify one-loop matching calculations, which we illustrate with examples. Of particular interest is the derivation of UV model-independent universal results, which reduce matching calculations of specific UV models to applications of master formulas. We show how such derivation can be done in a more concise manner than the previous literature, and discuss how additional structures that are not directly captured by existing universal results, including mixed heavy-light loops, open covariant derivatives, and mixed statistics, can be easily accounted for.

  14. A Smart Thermal Block Diagram Tool

    Science.gov (United States)

    Tsuyuki, Glenn; Miyake, Robert; Dodge, Kyle

    2008-01-01

    The presentation describes a Smart Thermal Block Diagram Tool. It is used by JPL's Team X in studying missions during the Pre-Phase A. It helps generate cost and mass estimates using proprietary data bases.

  15. Phase diagram to design passive nanostructures

    CERN Document Server

    Lee, Jeng Yi

    2015-01-01

    A phase diagram, defined by the amplitude square and phase of scattering coefficients for absorption cross-section in each individual channel, is introduced as a universal map on the electromagnetic properties for passive scatterers. General physical bounds are naturally revealed based on the intrinsic power conservation in a passive scattering system, entailing power competitions among scattering, absorption, and extinction. Exotic scattering and absorption phenomena, from resonant scattering, invisible cloaking, coherent perfect absorber, and subwavelength superscattering can all be illustrated in this phase diagram. With electrically small core-shell scatterers as an example, we demonstrate a systematic method to design field-controllable structures based on the allowed trajectories in the phase diagram. The proposed phase diagram not only provides a simple tool to design optical devices but also promotes a deep understanding on Mie's scattering theory.

  16. Atomic energy levels and Grotrian diagrams

    CERN Document Server

    Bashkin, Stanley

    1975-01-01

    Atomic Energy Levels and Grotrian Diagrams, Volume I: Hydrogen I - Phosphorus XV presents diagrams of various elements that show their energy level and electronic transitions. The book covers the first 15 elements according to their atomic number. The text will be of great use to researchers and practitioners of fields such as astrophysics that requires pictorial representation of the energy levels and electronic transitions of elements.

  17. Beyond Feynman Diagrams (1/3)

    CERN Document Server

    CERN. Geneva

    2013-01-01

    For decades the central theoretical tool for computing scattering amplitudes has been the Feynman diagram. However, Feynman diagrams are just too slow, even on fast computers, to be able to go beyond the leading order in QCD, for complicated events with many jets of hadrons in the final state. Such events are produced copiously at the LHC, and constitute formidable backgrounds to many searches for new physics. Over the past few years, alternative methods that go beyond ...

  18. The application of diagrams in architectural design

    Directory of Open Access Journals (Sweden)

    Dulić Olivera

    2014-01-01

    Full Text Available Diagrams in architecture represent the visualization of the thinking process, or selective abstraction of concepts or ideas translated into the form of drawings. In addition, they provide insight into the way of thinking about and in architecture, thus creating a balance between the visual and the conceptual. The subject of research presented in this paper are diagrams as a specific kind of architectural representation, and possibilities and importance of their application in the design process. Diagrams are almost old as architecture itself, and they are an element of some of the most important studies of architecture during all periods of history - which results in a large number of different definitions of diagrams, but also very different conceptualizations of their features, functions and applications. The diagrams become part of contemporary architectural discourse during the eighties and nineties of the twentieth century, especially through the work of architects like Bernard Tschumi, Peter Eisenman, Rem Koolhaas, SANAA and others. The use of diagrams in the design process allows unification of some of the essential aspects of the profession: architectural representation and design process, as well as the question of the concept of architectural and urban design at a time of rapid changes at all levels of contemporary society. The aim of the research is the analysis of the diagram as a specific medium for processing large amounts of information that the architect should consider and incorporate into the architectural work. On that basis, it is assumed that an architectural diagram allows the creator the identification and analysis of specific elements or ideas of physical form, thereby constantly maintaining concept of the integrity of the architectural work.

  19. QCD Phase Diagram with Imaginary Chemical Potential

    Directory of Open Access Journals (Sweden)

    Nakamura Atsushi

    2012-02-01

    Full Text Available We report our recent results on the QCD phase diagram obtained from the lattice QCD simulation. The location of the phase boundary between hadronic and QGP phases in the two-flavor QCD phase diagram is investigated. The imaginary chemical potential approach is employed, which is based on Monte Carlo simulations of the QCD with imaginary chemical potential and analytic continuation to the real chemical potential region.

  20. ISS EPS Orbital Replacement Unit Block Diagrams

    Science.gov (United States)

    Schmitz, Gregory V.

    2001-01-01

    The attached documents are being provided to Switching Power Magazine for information purposes. This magazine is writing a feature article on the International Space Station Electrical Power System, focusing on the switching power processors. These units include the DC-DC Converter Unit (DDCU), the Bi-directional Charge/Discharge Unit (BCDU), and the Sequential Shunt Unit (SSU). These diagrams are high-level schematics/block diagrams depicting the overall functionality of each unit.

  1. An Introduction to Binary Decision Diagrams

    DEFF Research Database (Denmark)

    Andersen, Henrik Reif

    1996-01-01

    This note is a short introduction to Binary Decision Diagrams (BDDs). It provides some background knowledge and describes the core algorithms. It is used in the course "C4340 Advanced Algorithms" at the Technical University of Denmark, autumn 1996.......This note is a short introduction to Binary Decision Diagrams (BDDs). It provides some background knowledge and describes the core algorithms. It is used in the course "C4340 Advanced Algorithms" at the Technical University of Denmark, autumn 1996....

  2. Random Young diagrams in a Rectangular Box

    DEFF Research Database (Denmark)

    Beltoft, Dan; Boutillier, Cédric; Enriquez, Nathanaël

    We exhibit the limit shape of random Young diagrams having a distribution proportional to the exponential of their area, and confined in a rectangular box. The Ornstein-Uhlenbeck bridge arises from the fluctuations around the limit shape.......We exhibit the limit shape of random Young diagrams having a distribution proportional to the exponential of their area, and confined in a rectangular box. The Ornstein-Uhlenbeck bridge arises from the fluctuations around the limit shape....

  3. Random Young diagrams in a Rectangular Box

    DEFF Research Database (Denmark)

    Beltoft, Dan; Boutillier, Cédric; Enriquez, Nathanaël

    We exhibit the limit shape of random Young diagrams having a distribution proportional to the exponential of their area, and confined in a rectangular box. The Ornstein-Uhlenbeck bridge arises from the fluctuations around the limit shape.......We exhibit the limit shape of random Young diagrams having a distribution proportional to the exponential of their area, and confined in a rectangular box. The Ornstein-Uhlenbeck bridge arises from the fluctuations around the limit shape....

  4. Misfit strain phase diagrams of epitaxial PMN–PT films

    Energy Technology Data Exchange (ETDEWEB)

    Khakpash, N.; Khassaf, H.; Rossetti, G. A. [Department of Materials Science and Engineering and Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269 (United States); Alpay, S. P., E-mail: p.alpay@ims.uconn.edu [Department of Materials Science and Engineering and Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269 (United States); Department of Physics, University of Connecticut, Storrs, Connecticut 06269 (United States)

    2015-02-23

    Misfit strain–temperature phase diagrams of three compositions of (001) pseudocubic (1 − x)·Pb (Mg{sub l/3}Nb{sub 2/3})O{sub 3} − x·PbTiO{sub 3} (PMN–PT) thin films are computed using a phenomenological model. Two (x = 0.30, 0.42) are located near the morphotropic phase boundary (MPB) of bulk PMN–PT at room temperature (RT) and one (x = 0.70) is located far from the MPB. The results show that it is possible to stabilize an adaptive monoclinic phase over a wide range of misfit strains. At RT, the stability region of this phase is much larger for PMN–PT compared to barium strontium titanate and lead zirconate titanate films.

  5. Misfit strain phase diagrams of epitaxial PMN-PT films

    Science.gov (United States)

    Khakpash, N.; Khassaf, H.; Rossetti, G. A.; Alpay, S. P.

    2015-02-01

    Misfit strain-temperature phase diagrams of three compositions of (001) pseudocubic (1 - x).Pb (Mgl/3Nb2/3)O3 - x.PbTiO3 (PMN-PT) thin films are computed using a phenomenological model. Two (x = 0.30, 0.42) are located near the morphotropic phase boundary (MPB) of bulk PMN-PT at room temperature (RT) and one (x = 0.70) is located far from the MPB. The results show that it is possible to stabilize an adaptive monoclinic phase over a wide range of misfit strains. At RT, the stability region of this phase is much larger for PMN-PT compared to barium strontium titanate and lead zirconate titanate films.

  6. Iberian Atlantic Margins Group investigates deep structure of ocean margins

    Science.gov (United States)

    The Iberian Atlantic Margins Group; Banda, Enric; Torne, Montserrat

    With recent seismic reflection data in hand, investigators for the Iberian Atlantic Margins project are preparing images of the deep continental and oceanic margins of Iberia. In 1993, the IAM group collected near vertical incidence seismic reflection data over a total distance of 3500 km along the North and Western Iberian Margins, Gorringe Bank Region and Gulf of Cadiz (Figure 1). When combined with data on the conjugate margin off Canada, details of the Iberian margin's deep structure should aid in distinguishing rift models and improve understanding of the processes governing the formation of margins.The North Iberian passive continental margin was formed during a Permian to Triassic phase of extension and matured during the early Cretaceous by rotation of the Iberian Peninsula with respect to Eurasia. From the late Cretaceous to the early Oligocene period, Iberia rotated in a counterclockwise direction around an axis located west of Lisbon. The plate boundary between Iberia and Eurasia, which lies along the Pyrenees, follows the north Spanish marginal trough, trends obliquely in the direction of the fossil Bay of Biscay triple junction, and continues along the Azores-Biscay Rise [Sibuet et al., 1994]. Following the NE-SW convergence of Iberia and Eurasia, the reactivation of the North Iberian continental margin resulted in the formation of a marginal trough and accretionary prism [Boillot et al., 1971].

  7. Free cooling phase-diagram of hard-spheres with short- and long-range interactions

    NARCIS (Netherlands)

    Gonzalez Briones, J.S.L.; Thornton, A.R.; Luding, S.

    2014-01-01

    We study the stability, the clustering and the phase-diagram of free cooling granular gases. The systems consist of mono-disperse particles with additional non-contact (long-range) interactions, and are simulated here by the event-driven molecular dynamics algorithm with discrete (short-range should

  8. TIME-TEMPERATURE-TRANSFORMATION (TTT) DIAGRAMS FOR FUTURE WASTE COMPOSITIONS

    Energy Technology Data Exchange (ETDEWEB)

    Billings, A.; Edwards, T.

    2010-07-08

    As a part of the Waste Acceptance Product Specifications (WAPS) for Vitrified High-Level Waste Forms defined by the Department of Energy - Office of Environmental Management, the waste form stability must be determined for each of the projected high-level waste (HLW) types at the Savannah River Site (SRS). Specifically, WAPS 1.4.1 requires the glass transition temperature (T{sub g}) to be defined and time-temperature-transformation (TTT) diagrams to be developed. The T{sub g} of a glass is an indicator of the approximate temperature where the supercooled liquid converts to a solid on cooling or conversely, where the solid begins to behave as a viscoelastic solid on heating. A TTT diagram identifies the crystalline phases that can form as a function of time and temperature for a given waste type or more specifically, the borosilicate glass waste form. In order to assess durability, the Product Consistency Test (PCT) was used and the durability results compared to the Environmental Assessment (EA) glass. The measurement of glass transition temperature and the development of TTT diagrams have already been performed for the seven Defense Waste Processing Facility (DWPF) projected compositions as defined in the Waste Form Compliance Plan (WCP) and in SRNL-STI-2009-00025. Additional phase transformation information exists for other projected compositions, but overall these compositions did not cover composition regions estimated for future waste processing. To develop TTT diagrams for future waste types, the Savannah River National Laboratory (SRNL) fabricated two caches of glass from reagent grade oxides to simulate glass compositions which would be likely processed with and without Al dissolution. These were used for glass transition temperature measurement and TTT diagram development. The glass transition temperatures of both glasses were measured using differential scanning calorimetry (DSC) and were recorded to be 448 C and 452 C. Using the previous TTT diagrams as

  9. Gaussian quantum marginal problem

    CERN Document Server

    Eisert, J; Sanders, B C; Tyc, T

    2007-01-01

    The quantum marginal problem asks what local spectra are consistent with a given state of a composite quantum system. This setting, also referred to as the question of the compatibility of local spectra, has several applications in quantum information theory. Here, we introduce the analogue of this statement for Gaussian states for any number of modes, and solve it in generality, for pure and mixed states, both concerning necessary and sufficient conditions. Formally, our result can be viewed as an analogue of the Sing-Thompson Theorem (respectively Horn's Lemma), characterizing the relationship between main diagonal elements and singular values of a complex matrix: We find necessary and sufficient conditions for vectors (d1, ..., dn) and (c1, ..., cn) to be the symplectic eigenvalues and symplectic main diagonal elements of a strictly positive real matrix, respectively. More physically speaking, this result determines what local temperatures or entropies are consistent with a pure or mixed Gaussian state of ...

  10. Leukocyte margination in a model microvessel

    Science.gov (United States)

    Freund, Jonathan B.

    2007-02-01

    The physiological inflammation response depends upon the multibody interactions of blood cells in the microcirculation that bring leukocytes (white blood cells) to the vessel walls. We investigate the fluid mechanics of this using numerical simulations of 29 red blood cells and one leukocyte flowing in a two-dimensional microvessel, with the cells modeled as linearly elastic shell membranes. Despite its obvious simplifications, this model successfully reproduces the increasingly blunted velocity profiles and increased leukocyte margination observed at lower shear rates in actual microvessels. Red cell aggregation is shown to be unnecessary for margination. The relative stiffness of the red cells in our simulations is varied by over a factor of 10, but the margination is found to be much less correlated with this than it is to changes associated with the blunting of the mean velocity profile at lower shear rates. While velocity around the leukocyte when it is near the wall depends upon the red cell properties, it changes little for strongly versus weakly marginating cases. In the more strongly marginating cases, however, a red cell is frequently observed to be leaning on the upstream side of the leukocyte and appears to stabilize it, preventing other red cells from coming between it and the wall. A well-known feature of the microcirculation is a near-wall cell-free layer. In our simulations, it is observed that the leukocyte's most probable position is at the edge of this layer. This wall stand-off distance increases with velocity following a scaling that would be expected for a lubrication mechanism, assuming that there were a nearly constant force pushing the cells toward the wall. The leukocyte's near-wall position is observed to be less stable with increasing mean stand-off distance, but this distance would have potentially greater effect on adhesion since the range of the molecular binding is so short.

  11. New SHRIMP U-Pb and 40Ar/39Ar constraints on the crustal stabilization of southern South America, from the margin of the Rio de Plata (Sierra de Ventana) craton to northern Patagonia

    Science.gov (United States)

    Tohver, E.; Cawood, P. A.; Rossello, E.; Lopez de Luchi, M. G.; Rapalini, A.; Jourdan, F.

    2008-12-01

    Two models exist to explain the late Paleozoic tectonic history for southern South America: an accretionary model of crustal growth through magmatism and a collisional model involving pre-existing continental elements, namely, the Rio de Plata craton and the possibly allochthonous terrane(s) of Patagonia, the Northern Patagonia Massif and the Deseado Massif. We report new U-Pb and 40Ar/39Ar results from rocks within a posited collision zone between the SW edge of the Rio de Plata craton and the northern margin of the Northern Patagonia Massif. Igneous basement samples from the Sierra de Ventana region, Buenos Aires province, were dated by ion microprobe (SHRIMP) analysis of zircon. A previously unrecognized occurrence of Paleoproterozoic basement indicates that the Rio de Plata craton extends ca.250 km farther west than considered. The majority of the basement rocks are shallow mid-Cambrian granitoids and rhyolites, including the rocks of the Cerro Colorado granite, which is intrusive into the sediments of the Curamalal Gp, signifying that these mature quartzites and conglomerates are older than early Cambrian in age, possibly correlated with the low-grade sedimentary rocks of the Tandilia Range that includes the La Tinta Fm. The 40Ar/39Ar ages from biotite, muscovite, and sericite from three different sheared basement localities demonstrates deformation in the latest Permian (265-260 Ma), ca. 20 Ma after the foreland deposition of the synorogenic Tunas Fm. in the upper Pilahuinco Gp, constrained by 282.4 ± 2.8 Ma zircon ages in volcanic ashbeds. Farther south, along the northern margin of the Northern Patagonian Massif, late Ordovician 40Ar/39Ar cooling ages of granites intrusive into the Cambro-Ordovician Nahuel Niyeu Fm. are consistent with the presence of Ordovician magmatism along the W edge of the Rio de Plata craton. These ages alternate with late Permian 40Ar/39Ar cooling ages from undeformed granites and pegmatites, as well as early Jurassic cross

  12. Pathway collages: personalized multi-pathway diagrams.

    Science.gov (United States)

    Paley, Suzanne; O'Maille, Paul E; Weaver, Daniel; Karp, Peter D

    2016-12-13

    Metabolic pathway diagrams are a classical way of visualizing a linked cascade of biochemical reactions. However, to understand some biochemical situations, viewing a single pathway is insufficient, whereas viewing the entire metabolic network results in information overload. How do we enable scientists to rapidly construct personalized multi-pathway diagrams that depict a desired collection of interacting pathways that emphasize particular pathway interactions? We define software for constructing personalized multi-pathway diagrams called pathway-collages using a combination of manual and automatic layouts. The user specifies a set of pathways of interest for the collage from a Pathway/Genome Database. Layouts for the individual pathways are generated by the Pathway Tools software, and are sent to a Javascript Pathway Collage application implemented using Cytoscape.js. That application allows the user to re-position pathways; define connections between pathways; change visual style parameters; and paint metabolomics, gene expression, and reaction flux data onto the collage to obtain a desired multi-pathway diagram. We demonstrate the use of pathway collages in two application areas: a metabolomics study of pathogen drug response, and an Escherichia coli metabolic model. Pathway collages enable facile construction of personalized multi-pathway diagrams.

  13. On the Evolution of Glaciated Continental Margins

    Science.gov (United States)

    Sverre Laberg, Jan; Rydningen, Tom Arne; Safronova, Polina A.; Forwick, Matthias

    2016-04-01

    has experienced a high sediment input from paleo-ice streams equal to an average erosion of 0.16 mm/yr in a source area dominated by crystalline rocks while the Troms margin experienced markedly lower input, ~0.03 mm/yr of erosion of crystalline rocks in an low-ice-flow sector of the Fennoscandian Ice Sheet. The slope gradient of the areas of high sediment input, the SW Barents Sea slope and the mid-Norwegian margin is mostly ~1 degree or less and dominated by large glacigenic debris flow deposits, outside Troms the slope is much steeper, up to 15 degrees. Here the relief includes gully-channel systems formed by turbidity currents. Off the western Barents Sea the development of large trough-mouth-fans is related to the spatial stability of paleo-ice streams over repeated peak glacials, offshore Troms smaller trough-mouth-fans implies spatially stable paleo-ice streams also here while more unstable paleo-ice streams was one of the main factors that led to the development of a prograding wedge offshore of mid-Norway. All areas have been affected by small- and large-scale submarine landslides. From a detailed study of the NW Barents Sea margin the deposits from these processes were found to represent up to one quarter of the total volume of sediments.

  14. The Semiotic Structure of Geometry Diagrams: How Textbook Diagrams Convey Meaning

    Science.gov (United States)

    Dimmel, Justin K.; Herbst, Patricio G.

    2015-01-01

    Geometry diagrams use the visual features of specific drawn objects to convey meaning about generic mathematical entities. We examine the semiotic structure of these visual features in two parts. One, we conduct a semiotic inquiry to conceptualize geometry diagrams as mathematical texts that comprise choices from different semiotic systems. Two,…

  15. Stage line diagram: An age-conditional reference diagram for tracking development

    NARCIS (Netherlands)

    Buuren, S. van; Ooms, J.C.L.

    2009-01-01

    This paper presents a method for calculating stage line diagrams, a novel type of reference diagram useful for tracking developmental processes over time. Potential fields of applications include: dentistry (tooth eruption), oncology (tumor grading, cancer staging), virology (HIV infection and disea

  16. Stage line diagram: an age-conditional reference diagram for tracking development.

    NARCIS (Netherlands)

    Van Buuren, S.; Ooms, J.C.L.

    2009-01-01

    This paper presents a method for calculating stage line diagrams, a novel type of reference diagram useful for tracking developmental processes over time. Potential fields of applications include: dentistry (tooth eruption), oncology (tumor grading, cancer staging), virology (HIV infection and disea

  17. Stage line diagram: an age-conditional reference diagram for tracking development.

    NARCIS (Netherlands)

    Van Buuren, S.; Ooms, J.C.L.

    2009-01-01

    This paper presents a method for calculating stage line diagrams, a novel type of reference diagram useful for tracking developmental processes over time. Potential fields of applications include: dentistry (tooth eruption), oncology (tumor grading, cancer staging), virology (HIV infection and disea

  18. Fishbone Diagrams: Organize Reading Content with a "Bare Bones" Strategy

    Science.gov (United States)

    Clary, Renee; Wandersee, James

    2010-01-01

    Fishbone diagrams, also known as Ishikawa diagrams or cause-and-effect diagrams, are one of the many problem-solving tools created by Dr. Kaoru Ishikawa, a University of Tokyo professor. Part of the brilliance of Ishikawa's idea resides in the simplicity and practicality of the diagram's basic model--a fish's skeleton. This article describes how…

  19. Fishbone Diagrams: Organize Reading Content with a "Bare Bones" Strategy

    Science.gov (United States)

    Clary, Renee; Wandersee, James

    2010-01-01

    Fishbone diagrams, also known as Ishikawa diagrams or cause-and-effect diagrams, are one of the many problem-solving tools created by Dr. Kaoru Ishikawa, a University of Tokyo professor. Part of the brilliance of Ishikawa's idea resides in the simplicity and practicality of the diagram's basic model--a fish's skeleton. This article describes how…

  20. Visualizing Metrics on Areas of Interest in Software Architecture Diagrams

    NARCIS (Netherlands)

    Byelas, Heorhiy; Telea, Alexandru; Eades, P; Ertl, T; Shen, HW

    2009-01-01

    We present a new method for the combined visualization of software architecture diagrams, Such as UML class diagrams or component diagrams, and software metrics defined on groups of diagram elements. Our method extends an existing rendering technique for the so-called areas of interest in system arc

  1. Margins in high temperature leak-before-break assessments

    Energy Technology Data Exchange (ETDEWEB)

    Budden, P.J.; Hooton, D.G.

    1997-04-01

    Developments in the defect assessment procedure R6 to include high-temperature mechanisms in Leak-before-Break arguments are described. In particular, the effect of creep on the time available to detect a leak and on the crack opening area, and hence leak rate, is discussed. The competing influence of these two effects is emphasized by an example. The application to Leak-before-Break of the time-dependent failure assessment diagram approach for high temperature defect assessment is then outlined. The approach is shown to be of use in assessing the erosion of margins by creep.

  2. Stability of Rocket Flight during Burning

    Directory of Open Access Journals (Sweden)

    T. N. Srivastava

    1967-10-01

    Full Text Available Stability of the rocket motion during burning is discussed taking into consideration gravity, aerodynamic forces and torques. Conditions for stabilizing the rocket motion are investigated. Analysis for initial and final phases of burning is given separately. Stability regions of the projected motions on two dimensional co-ordinate planes are obtained and thereby stability region of the actual motion is derived. Stability diagrams illustrate statically and dynamically stable and unstable regions.

  3. Phase diagram of a truncated tetrahedral model

    Science.gov (United States)

    Krcmar, Roman; Gendiar, Andrej; Nishino, Tomotoshi

    2016-08-01

    Phase diagram of a discrete counterpart of the classical Heisenberg model, the truncated tetrahedral model, is analyzed on the square lattice, when the interaction is ferromagnetic. Each spin is represented by a unit vector that can point to one of the 12 vertices of the truncated tetrahedron, which is a continuous interpolation between the tetrahedron and the octahedron. Phase diagram of the model is determined by means of the statistical analog of the entanglement entropy, which is numerically calculated by the corner transfer matrix renormalization group method. The obtained phase diagram consists of four different phases, which are separated by five transition lines. In the parameter region, where the octahedral anisotropy is dominant, a weak first-order phase transition is observed.

  4. Functionality Semantics of Predicate Data Flow Diagram

    Institute of Scientific and Technical Information of China (English)

    高晓雷; 缪淮扣; 刘玲

    2004-01-01

    SOZL (structured methodology + object-oriented methodology + Z language) is a language that attempts to integrate structured method, object-oriented method and formal method. The core of this language is predicate data flow diagram (PDFD). In order to eliminate the ambiguity of predicate data flow diagrams and their associated textual specifications, a formalization of the syntax and semantics of predicate data flow diagrams is necessary. In this paper we use Z notation to define an abstract syntax and the related structural constraints for the PDFD notation, and provide it with an axiomatic semantics based on the concept of data availability and functionality of predicate operation. Finally, an example is given to establish functionality consistent decomposition on hierarchical PDFD (HPDFD).

  5. Phase diagrams of diluted transverse Ising nanowire

    Energy Technology Data Exchange (ETDEWEB)

    Bouhou, S.; Essaoudi, I. [Laboratoire de Physique des Matériaux et Modélisation, des Systèmes, (LP2MS), Unité Associée au CNRST-URAC 08, University of Moulay Ismail, Physics Department, Faculty of Sciences, B.P. 11201 Meknes (Morocco); Ainane, A., E-mail: ainane@pks.mpg.de [Laboratoire de Physique des Matériaux et Modélisation, des Systèmes, (LP2MS), Unité Associée au CNRST-URAC 08, University of Moulay Ismail, Physics Department, Faculty of Sciences, B.P. 11201 Meknes (Morocco); Max-Planck-Institut für Physik Complexer Systeme, Nöthnitzer Str. 38 D-01187 Dresden (Germany); Saber, M. [Laboratoire de Physique des Matériaux et Modélisation, des Systèmes, (LP2MS), Unité Associée au CNRST-URAC 08, University of Moulay Ismail, Physics Department, Faculty of Sciences, B.P. 11201 Meknes (Morocco); Max-Planck-Institut für Physik Complexer Systeme, Nöthnitzer Str. 38 D-01187 Dresden (Germany); Ahuja, R. [Condensed Matter Theory Group, Department of Physics and Astronomy, Uppsala University, 75120 Uppsala (Sweden); Dujardin, F. [Laboratoire de Chimie et Physique des Milieux Complexes (LCPMC), Institut de Chimie, Physique et Matériaux (ICPM), 1 Bd. Arago, 57070 Metz (France)

    2013-06-15

    In this paper, the phase diagrams of diluted Ising nanowire consisting of core and surface shell coupling by J{sub cs} exchange interaction are studied using the effective field theory with a probability distribution technique, in the presence of transverse fields in the core and in the surface shell. We find a number of characteristic phenomena. In particular, the effect of concentration c of magnetic atoms, the exchange interaction core/shell, the exchange in surface and the transverse fields in core and in surface shell of phase diagrams are investigated. - Highlights: ► We use the EFT to investigate the phase diagrams of Ising transverse nanowire. ► Ferrimagnetic and ferromagnetic cases are investigated. ► The effects of the dilution and the transverse fields in core and shell are studied. ► Behavior of the transition temperature with the exchange interaction is given.

  6. Increasing entropy for colloidal stabilization

    Science.gov (United States)

    Mo, Songping; Shao, Xuefeng; Chen, Ying; Cheng, Zhengdong

    2016-11-01

    Stability is of paramount importance in colloidal applications. Attraction between colloidal particles is believed to lead to particle aggregation and phase separation; hence, stability improvement can be achieved through either increasing repulsion or reducing attraction by modifying the fluid medium or by using additives. Two traditional mechanisms for colloidal stability are electrostatic stabilization and steric stabilization. However, stability improvement by mixing attractive and unstable particles has rarely been considered. Here, we emphasize the function of mixing entropy in colloidal stabilization. Dispersion stability improvement is demonstrated by mixing suspensions of attractive nanosized titania spheres and platelets. A three-dimensional phase diagram is proposed to illustrate the collaborative effects of particle mixing and particle attraction on colloidal stability. This discovery provides a novel method for enhancing colloidal stability and opens a novel opportunity for engineering applications.

  7. The topological phase diagram of cimetidine: A case of overall monotropy.

    Science.gov (United States)

    Céolin, R; Rietveld, I B

    2017-03-01

    Cimetidine is a histamine H2-receptor antagonist used against peptic ulcers. It is known to exhibit crystalline polymorphism. Forms A and D melt within 0.35 degrees from each other and the enthalpies of fusion are similar as well. The present paper demonstrates how to construct a pressure-temperature phase diagram with only calorimetric and volumetric data available. The phase diagram provides the stability domains and the phase equilibria for the phases A, D, the liquid and the vapor. Cimetidine is overall monotropic with form D the only stable solid phase.

  8. A pseudo-haptic knot diagram interface

    Science.gov (United States)

    Zhang, Hui; Weng, Jianguang; Hanson, Andrew J.

    2011-01-01

    To make progress in understanding knot theory, we will need to interact with the projected representations of mathematical knots which are of course continuous in 3D but significantly interrupted in the projective images. One way to achieve such a goal would be to design an interactive system that allows us to sketch 2D knot diagrams by taking advantage of a collision-sensing controller and explore their underlying smooth structures through a continuous motion. Recent advances of interaction techniques have been made that allow progress to be made in this direction. Pseudo-haptics that simulates haptic effects using pure visual feedback can be used to develop such an interactive system. This paper outlines one such pseudo-haptic knot diagram interface. Our interface derives from the familiar pencil-and-paper process of drawing 2D knot diagrams and provides haptic-like sensations to facilitate the creation and exploration of knot diagrams. A centerpiece of the interaction model simulates a "physically" reactive mouse cursor, which is exploited to resolve the apparent conflict between the continuous structure of the actual smooth knot and the visual discontinuities in the knot diagram representation. Another value in exploiting pseudo-haptics is that an acceleration (or deceleration) of the mouse cursor (or surface locator) can be used to indicate the slope of the curve (or surface) of whom the projective image is being explored. By exploiting these additional visual cues, we proceed to a full-featured extension to a pseudo-haptic 4D visualization system that simulates the continuous navigation on 4D objects and allows us to sense the bumps and holes in the fourth dimension. Preliminary tests of the software show that main features of the interface overcome some expected perceptual limitations in our interaction with 2D knot diagrams of 3D knots and 3D projective images of 4D mathematical objects.

  9. Stability and metastability of bromine clathrate polymorphs.

    Science.gov (United States)

    Nguyen, Andrew H; Molinero, Valeria

    2013-05-23

    Clathrate hydrates are crystals in which water forms a network of fully hydrogen-bonded polyhedral cages that contain small guests. Clathrate hydrates occur mostly in two cubic crystal polymorphs, sI and sII. Bromine is one of two guests that yield a hydrate with the tetragonal structure (TS), the topological dual of the Frank-Kasper σ phase. There has been a long-standing disagreement on whether bromine hydrate also forms metastable sI and sII crystals. To date there are no data on the thermodynamic range of stability (e.g., the melting temperatures) of the metastable polymorphs. Here we use molecular dynamics simulations with the coarse-grained model of water mW to (i) investigate the thermodynamic stability of the empty and guest-filled the sI, sII, TS, and HS-I hydrate polymorphs, (ii) develop a coarse-grained model of bromine compatible with mW water, and (iii) evaluate the stability of the bromine hydrate polymorphs. The mW model predicts the same relative energy of the empty clathrate polymorphs and the same phase diagram as a function of water-guest interaction than the fully atomistic TIP4P water model. There is a narrow region in water-guest parameter space for which TS is marginally more stable than sI or sII. We parametrize a coarse-grained model of bromine compatible with mW water and use it to determine the order of stability of the bromine hydrate polymorphs. The melting temperatures of the bromine hydrate polymorphs predicted by the coarse-grained model are 281 ± 1 K for TS, 279 ± 1 K for sII, and 276 ± 1 K for sI. The closeness of the melting temperatures supports the plausibility of formation of metastable sII and sI bromine hydrates.

  10. MDM: A Mode Diagram Modeling Framework

    DEFF Research Database (Denmark)

    Wang, Zheng; Pu, Geguang; Li, Jianwen

    2012-01-01

    systems are widely used in the above-mentioned safety-critical embedded domains, there is lack of domain-specific formal modelling languages for such systems in the relevant industry. To address this problem, we propose a formal visual modeling framework called mode diagram as a concise and precise way...... checking technique can then be used to verify the mode diagram models against desired properties. To demonstrate the viability of our approach, we have applied our modelling framework to some real life case studies from industry and helped detect two design defects for some spacecraft control systems....

  11. DEPENDENCE ANALYSIS FOR UML CLASS DIAGRAMS

    Institute of Scientific and Technical Information of China (English)

    Wu Fangjun; Yi Tong

    2004-01-01

    Though Unified Modeling Language (UML) has been widely used in software development, the major problems confronted lie in comprehension and testing. Dependence analysis is an important approach to analyze, understand, test and maintain programs. A new kind of dependence analysis method for UML class diagrams is developed. A set of dependence relations is definedcorresponding to the relations among classes. Thus, the dependence graph of UML class diagram can be constructed from these dependence relations. Based on this model, both slicing and measurement coupling are further given as its two applications.

  12. Phase diagrams modified by interfacial penalties

    Directory of Open Access Journals (Sweden)

    Atanacković T.M.

    2007-01-01

    Full Text Available The conventional forms of phase diagrams are constructed without consideration of interfacial energies and they represent an impor­tant tool for chemical engineers and metallurgists. If interfacial energies are taken into consideration, it is intuitively obvious that the regions of phase equilibria must become smaller, because there is a penalty on the formation of interfaces. We investigate this phe­nomenon qualitatively for a one-dimensional model, in which the phases occur as layers rather than droplets or bubbles. The modified phase diagrams are shown in Chapters 3 and 4.

  13. Partial chord diagrams and matrix models

    DEFF Research Database (Denmark)

    Andersen, Jørgen Ellegaard; Fuji, Hiroyuki; Manabe, Masahide

    spectrum. Furthermore, we consider the boundary length and point spectrum that unifies the last two types of spectra. We introduce matrix models that encode generating functions of partial chord diagrams filtered by each of these spectra. Using these matrix models, we derive partial differential equations......In this article, the enumeration of partial chord diagrams is discussed via matrix model techniques. In addition to the basic data such as the number of backbones and chords, we also consider the Euler characteristic, the backbone spectrum, the boundary point spectrum, and the boundary length...... – obtained independently by cut-and-join arguments in an earlier work – for the corresponding generating functions....

  14. The Voronoi diagram of circles made easy

    DEFF Research Database (Denmark)

    Anton, François; Mioc, Darka; Gold, Christopher

    2007-01-01

    Proximity queries among circles could be effectively answered if the Delaunay graph for sets of circles could be computed in an efficient and exact way. In this paper, we first show a necessary and sufficient condition of connectivity of the Voronoi diagram of circles. Then, we show how the Delau......Proximity queries among circles could be effectively answered if the Delaunay graph for sets of circles could be computed in an efficient and exact way. In this paper, we first show a necessary and sufficient condition of connectivity of the Voronoi diagram of circles. Then, we show how...

  15. Workers' marginal costs of commuting

    DEFF Research Database (Denmark)

    van Ommeren, Jos; Fosgerau, Mogens

    2009-01-01

    This paper applies a dynamic search model to estimate workers' marginal costs of commuting, including monetary and time costs. Using data on workers' job search activity as well as moving behaviour, for the Netherlands, we provide evidence that, on average, workers' marginal costs of one hour...

  16. Phase Diagrams of Instabilities in Compressed Film-Substrate Systems.

    Science.gov (United States)

    Wang, Qiming; Zhao, Xuanhe

    2014-05-01

    Subject to a compressive membrane stress, an elastic film bonded on a substrate can become unstable, forming wrinkles, creases or delaminated buckles. Further increasing the compressive stress can induce advanced modes of instabilities including period-doubles, folds, localized ridges, delamination, and coexistent instabilities. While various instabilities in film-substrate systems under compression have been analyzed separately, a systematic and quantitative understanding of these instabilities is still elusive. Here we present a joint experimental and theoretical study to systematically explore the instabilities in elastic film-substrate systems under uniaxial compression. We use the Maxwell stability criterion to analyze the occurrence and evolution of instabilities analogous to phase transitions in thermodynamic systems. We show that the moduli of the film and the substrate, the film-substrate adhesion strength, the film thickness, and the prestretch in the substrate determine various modes of instabilities. Defects in the film-substrate system can facilitate it to overcome energy barriers during occurrence and evolution of instabilities. We provide a set of phase diagrams to predict both initial and advanced modes of instabilities in compressed film-substrate systems. The phase diagrams can be used to guide the design of film-substrate systems to achieve desired modes of instabilities.

  17. Modeling the phase diagram of carbon

    NARCIS (Netherlands)

    Ghiringhelli, L.M.; Los, J.H.; Meijer, E.J.; Fasolino, A.; Frenkel, D.

    2005-01-01

    We determined the phase diagram involving diamond, graphite, and liquid carbon using a recently developed semiempirical potential. Using accurate free-energy calculations, we computed the solid-solid and solid-liquid phase boundaries for pressures and temperatures up to 400 GPa and 12 000 K, respect

  18. Orphan-Free Anisotropic Voronoi Diagrams

    CERN Document Server

    Canas, Guillermo D

    2011-01-01

    We describe conditions under which an appropriately-defined anisotropic Voronoi diagram of a set of sites in Euclidean space is guaranteed to be composed of connected cells in any number of dimensions. These conditions are natural for problems in optimization and approximation, and algorithms already exist to produce sets of sites that satisfy them.

  19. The BFKL Pomeron calculus: Summing enhanced diagrams

    Energy Technology Data Exchange (ETDEWEB)

    Levin, E., E-mail: leving@post.tau.ac.il [Department of Particle Physics, School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978 (Israel); Departamento de Fisica, Universidad Tecnica Federico Santa Maria, and Centro Cientifico-Tecnologico de Valparaiso, Casilla 110-V, Valparaiso (Chile); Miller, J., E-mail: jeremy.miller@ist.utl.pt [Department of Particle Physics, School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978 (Israel); CENTRA, Departamento de Fisica, Instituto Superior Tecnico (IST), Av. Rovisco Pais, 1049-001 Lisboa (Portugal)

    2012-07-01

    The goal of this paper is to sum over a class of enhanced diagrams, and derive a new Pomeron Green function. It is found that this sum gives the Pomeron contribution to the scattering amplitude that decreases with energy. In other words, we found that the total cross section of two colourless dipoles of small but equal sizes, falls down at high energies.

  20. Phase Diagrams of Strongly Interacting Theories

    DEFF Research Database (Denmark)

    Sannino, Francesco

    2010-01-01

    We summarize the phase diagrams of SU, SO and Sp gauge theories as function of the number of flavors, colors, and matter representation as well as the ones of phenomenologically relevant chiral gauge theories such as the Bars-Yankielowicz and the generalized Georgi-Glashow models. We finally repo...

  1. Geometrical splitting and reduction of Feynman diagrams

    Science.gov (United States)

    Davydychev, Andrei I.

    2016-10-01

    A geometrical approach to the calculation of N-point Feynman diagrams is reviewed. It is shown that the geometrical splitting yields useful connections between Feynman integrals with different momenta and masses. It is demonstrated how these results can be used to reduce the number of variables in the occurring functions.

  2. Influence Diagrams for Optimal Maintenance Planning

    DEFF Research Database (Denmark)

    Friis-Hansen, Andreas

    2000-01-01

    Over the last two decades Bayesian networks and influence diagrams have received notable attention within the field of artificial intelligence and expert systems. During the last few years the technology has been further developed for problem solving within other engineering fields. The objective...

  3. The classification of diagrams in perturbation theory

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, D.R.; Afnan, I.R. [School of Physical Sciences, The Flinders University of South Australia, GPO Box 2100, Adelaide 5001 (Australia)

    1995-06-01

    The derivation of scattering equations connecting the amplitudes obtained from diagrammatic expansions is of interest in many branches of physics. One method for deriving such equations is the classification-of-diagrams technique of Taylor. However, as we shall explain in this paper, there are certain points of Taylor`s method which require clarification. First, it is not clear whether Taylor`s original method is equivlant to the simpler classification-of-diagrams scheme used by Thomas, Rinat, Afnan, and Blankleider (TRAB). Second, when the Taylor method is applied to certain problems in a time-dependent perturbation theory it leads to the over-counting of some diagrams. This paper first restates Taylor`s method, in the process uncovering reasons why certain diagrams might be double-counted in the Taylor method. In then explores how far Taylor`s method is equivalent to the simpler TRAB method. Finally, it examines precisely why the double-counting occurs in Taylor`s method and derives corrections which compensate for this double-counting. {copyright} 1995 Academic Press, Inc.

  4. The Classification of Diagrams in Perturbation Theory

    Science.gov (United States)

    Phillips, D. R.; Afnan, I. R.

    1995-06-01

    The derivation of scattering equations connecting the amplitudes obtained from diagrammatic expansions is of interest in many branches of physics. One method for deriving such equations is the classification-of-diagrams technique of Taylor. However, as we shall explain in this paper, there are certain points of Taylor's method which require clarification. Firstly, it is not clear whether Taylor's original method is equivalent to the simpler classification-of-diagrams scheme used by Thomas, Rinat, Afnan, and Blankleider (TRAB). Secondly, when the Taylor method is applied to certain problems in a time-dependent perturbation theory it leads to the over-counting of some diagrams. This paper first restates Taylor's method, in the process uncovering reasons why certain diagrams might be double-counted in the Taylor method. It then explores how far Taylor's method is equivalent to the simpler TRAB method. Finally, it examines precisely why the double-counting occurs in Taylor's method and derives corrections which compensate for this double-counting.

  5. Diagram of a LEP superconducting cavity

    CERN Multimedia

    1991-01-01

    This diagram gives a schematic representation of the superconducting radio-frequency cavities at LEP. Liquid helium is used to cool the cavity to 4.5 degrees above absolute zero so that very high electric fields can be produced, increasing the operating energy of the accelerator. Superconducting cavities were used only in the LEP-2 phase of the accelerator, from 1996 to 2000.

  6. Influence Diagrams for Optimal Maintenance Planning

    DEFF Research Database (Denmark)

    Friis-Hansen, Andreas

    2000-01-01

    Over the last two decades Bayesian networks and influence diagrams have received notable attention within the field of artificial intelligence and expert systems. During the last few years the technology has been further developed for problem solving within other engineering fields. The objective...

  7. Phase diagram distortion from traffic parameter averaging.

    NARCIS (Netherlands)

    Stipdonk, H. Toorenburg, J. van & Postema, M.

    2010-01-01

    Motorway traffic congestion is a major bottleneck for economic growth. Therefore, research of traffic behaviour is carried out in many countries. Although well describing the undersaturated free flow phase as an almost straight line in a (k,q)-phase diagram, congested traffic observations and

  8. Weight diagram construction of Lax operators

    Energy Technology Data Exchange (ETDEWEB)

    Carbon, S.L.; Piard, E.J.

    1991-10-01

    We review and expand methods introduced in our previous paper. It is proved that cyclic weight diagrams corresponding to representations of affine Lie algebras allow one to construct the associated Lax operator. The resultant Lax operator is in the Miura-like form and generates the modified KdV equations. The algorithm is extended to the super-symmetric case.

  9. Solution space diagram in conflict detection scenarios

    NARCIS (Netherlands)

    Rahman, S.M.A.; Borst, C.; Mulder, M.; Van Paassen, M.M.

    2015-01-01

    This research investigates the use of Solution Space Diagram (SSD) as a measure of sector complexity and also as a predictor of performance and workload, focusing on the scenarios regarding Air Traffic Controller (ATCO)’s ability to detect future conflicts. A human-in-the-loop experiment with varyin

  10. Visualizing Multivariate Attributes on Software Diagrams

    NARCIS (Netherlands)

    Byelas, Heorhiy; Telea, Alexandru; Winter, A; Knodel, J

    2009-01-01

    Software architecture diagrams and metrics are well-known and heavily used in many areas in software engineering. However they are rarely combined in one (visual) representation. Although there are some advances in this direction, there are also some limitations. In this research, we study how to ov

  11. Phase Diagram of Vertically Shaken Granular Matter

    CERN Document Server

    Eshuis, P; Lohse, D; Van der Meer, D; Van der Weele, K; Bos, Robert; Eshuis, Peter; Lohse, Detlef; Meer, Devaraj van der; Weele, Ko van der

    2006-01-01

    A shallow, vertically shaken granular bed in a quasi 2-D container is studied experimentally yielding a wider variety of phenomena than in any previous study: (1) bouncing bed, (2) undulations, (3) granular Leidenfrost effect, (4) convection rolls, and (5) granular gas. These phenomena and the transitions between them are characterized by dimensionless control parameters and combined in a full experimental phase diagram.

  12. Spin wave Feynman diagram vertex computation package

    Science.gov (United States)

    Price, Alexander; Javernick, Philip; Datta, Trinanjan

    Spin wave theory is a well-established theoretical technique that can correctly predict the physical behavior of ordered magnetic states. However, computing the effects of an interacting spin wave theory incorporating magnons involve a laborious by hand derivation of Feynman diagram vertices. The process is tedious and time consuming. Hence, to improve productivity and have another means to check the analytical calculations, we have devised a Feynman Diagram Vertex Computation package. In this talk, we will describe our research group's effort to implement a Mathematica based symbolic Feynman diagram vertex computation package that computes spin wave vertices. Utilizing the non-commutative algebra package NCAlgebra as an add-on to Mathematica, symbolic expressions for the Feynman diagram vertices of a Heisenberg quantum antiferromagnet are obtained. Our existing code reproduces the well-known expressions of a nearest neighbor square lattice Heisenberg model. We also discuss the case of a triangular lattice Heisenberg model where non collinear terms contribute to the vertex interactions.

  13. Image Attributes: A Study of Scientific Diagrams.

    Science.gov (United States)

    Brunskill, Jeff; Jorgensen, Corinne

    2002-01-01

    Discusses advancements in imaging technology and increased user access to digital images, as well as efforts to develop adequate indexing and retrieval methods for image databases. Describes preliminary results of a study of undergraduates that explored the attributes naive subjects use to describe scientific diagrams. (Author/LRW)

  14. Phase diagram distortion from traffic parameter averaging.

    NARCIS (Netherlands)

    Stipdonk, H. Toorenburg, J. van & Postema, M.

    2010-01-01

    Motorway traffic congestion is a major bottleneck for economic growth. Therefore, research of traffic behaviour is carried out in many countries. Although well describing the undersaturated free flow phase as an almost straight line in a (k,q)-phase diagram, congested traffic observations and theori

  15. On traces of tensor representations of diagrams

    NARCIS (Netherlands)

    A. Schrijver

    2015-01-01

    Let T be an (abstract) set of types, and let (unknown symbol), o : T -> Z(+). A T-diagram is a locally ordered directed graph G equipped with a function tau : V (G) -> T such that each vertex v of G has indegree (unknown symbol)(tau(v)) and outdegree o(tau(v)). (A directed graph is locally ordered i

  16. Complexities of One-Component Phase Diagrams

    Science.gov (United States)

    Ciccioli, Andrea; Glasser, Leslie

    2011-01-01

    For most materials, the solid at and near the triple-point temperature is denser than the liquid with which it is in equilibrium. However, for water and certain other materials, the densities of the phases are reversed, with the solid being less dense. The profound consequences for the appearance of the "pVT" diagram of one-component materials…

  17. From ergodicity to extended phase diagrams.

    Science.gov (United States)

    Woodley, Scott M; Sokol, Alexey A

    2012-04-16

    Structure prediction of stable and metastable phases is put on equal footing for the first time, with a solid thermodynamical background. How to estimate the lifetime of metastable phases is demonstrated by recent groundbreaking work of Jansen, Pentin, and Schön. At the heart lies the exploration of the Gibbs free-energy landscapes and the extended phase diagrams for complex systems.

  18. Fog Machines, Vapors, and Phase Diagrams

    Science.gov (United States)

    Vitz, Ed

    2008-01-01

    A series of demonstrations is described that elucidate the operation of commercial fog machines by using common laboratory equipment and supplies. The formation of fogs, or "mixing clouds", is discussed in terms of the phase diagram for water and other chemical principles. The demonstrations can be adapted for presentation suitable for elementary…

  19. The non-equilibrium phase diagrams of flow-induced crystallization and melting of polyethylene.

    Science.gov (United States)

    Wang, Zhen; Ju, Jianzhu; Yang, Junsheng; Ma, Zhe; Liu, Dong; Cui, Kunpeng; Yang, Haoran; Chang, Jiarui; Huang, Ningdong; Li, Liangbin

    2016-09-09

    Combining extensional rheology with in-situ synchrotron ultrafast x-ray scattering, we studied flow-induced phase behaviors of polyethylene (PE) in a wide temperature range up to 240 °C. Non-equilibrium phase diagrams of crystallization and melting under flow conditions are constructed in stress-temperature space, composing of melt, non-crystalline δ, hexagonal and orthorhombic phases. The non-crystalline δ phase is demonstrated to be either a metastable transient pre-order for crystallization or a thermodynamically stable phase. Based on the non-equilibrium phase diagrams, nearly all observations in flow-induced crystallization (FIC) of PE can be well understood. The interplay of thermodynamic stabilities and kinetic competitions of the four phases creates rich kinetic pathways for FIC and diverse final structures. The non-equilibrium flow phase diagrams provide a detailed roadmap for precisely processing of PE with designed structures and properties.

  20. Direct Surge Margin Control for Aeroengines Based on Improved SVR Machine and LQR Method

    Directory of Open Access Journals (Sweden)

    Haibo Zhang

    2013-01-01

    Full Text Available A novel scheme of high stability engine control (HISTEC on the basis of an improved linear quadratic regulator (ILQR, called direct surge margin control, is derived for super-maneuver flights. Direct surge margin control, which is different from conventional control scheme, puts surge margin into the engine closed-loop system and takes surge margin as controlled variable directly. In this way, direct surge margin control can exploit potential performance of engine more effectively with a decrease of engine stability margin which usually happened in super-maneuver flights. For conquering the difficulty that aeroengine surge margin is undetectable, an approach based on improved support vector regression (SVR machine is proposed to construct a surge margin prediction model. The surge margin modeling contains two parts: a baseline model under no inlet distortion states and the calculation for surge margin loss under supermaneuvering flight conditions. The previous one is developed using neural network method, the inputs of which are selected by a weighted feature selection algorithm. Considering the hysteresis between pilot input and angle of attack output, an online scrolling window least square support vector regression (LSSVR method is employed to firstly estimate inlet distortion index and further compute surge margin loss via some empirical look-up tables.

  1. Bioeconomic Sustainability of Cellulosic Biofuel Production on Marginal Lands

    Science.gov (United States)

    Gutierrez, Andrew Paul; Ponti, Luigi

    2009-01-01

    The use of marginal land (ML) for lignocellulosic biofuel production is examined for system stability, resilience, and eco-social sustainability. A North American prairie grass system and its industrialization for maximum biomass production using biotechnology and agro-technical inputs is the focus of the analysis. Demographic models of ML biomass…

  2. Bioeconomic Sustainability of Cellulosic Biofuel Production on Marginal Lands

    Science.gov (United States)

    Gutierrez, Andrew Paul; Ponti, Luigi

    2009-01-01

    The use of marginal land (ML) for lignocellulosic biofuel production is examined for system stability, resilience, and eco-social sustainability. A North American prairie grass system and its industrialization for maximum biomass production using biotechnology and agro-technical inputs is the focus of the analysis. Demographic models of ML biomass…

  3. Students' different understandings of class diagrams

    Science.gov (United States)

    Boustedt, Jonas

    2012-03-01

    The software industry needs well-trained software designers and one important aspect of software design is the ability to model software designs visually and understand what visual models represent. However, previous research indicates that software design is a difficult task to many students. This article reports empirical findings from a phenomenographic investigation on how students understand class diagrams, Unified Modeling Language (UML) symbols, and relations to object-oriented (OO) concepts. The informants were 20 Computer Science students from four different universities in Sweden. The results show qualitatively different ways to understand and describe UML class diagrams and the "diamond symbols" representing aggregation and composition. The purpose of class diagrams was understood in a varied way, from describing it as a documentation to a more advanced view related to communication. The descriptions of class diagrams varied from seeing them as a specification of classes to a more advanced view, where they were described to show hierarchic structures of classes and relations. The diamond symbols were seen as "relations" and a more advanced way was seeing the white and the black diamonds as different symbols for aggregation and composition. As a consequence of the results, it is recommended that UML should be adopted in courses. It is briefly indicated how the phenomenographic results in combination with variation theory can be used by teachers to enhance students' possibilities to reach advanced understanding of phenomena related to UML class diagrams. Moreover, it is recommended that teachers should put more effort in assessing skills in proper usage of the basic symbols and models and students should be provided with opportunities to practise collaborative design, e.g. using whiteboards.

  4. Phase diagrams and heterogeneous equilibria a practical introduction

    CERN Document Server

    Predel, Bruno; Pool, Monte

    2004-01-01

    This graduate-level textbook provides an introduction to the practical application of phase diagrams. It is intended for students and researchers in chemistry, metallurgy, mineralogy, and materials science as well as in engineering and physics. Heterogeneous equilibria are described by a minimum of theory illustrated by practical examples and realistic case discussions from the different fields of application. The treatment of the physical and energetic background of phase equilibria leads to the discussion of the thermodynamics of mixtures and the correlation between energetics and composition. Thus, tools for the prediction of energetic, structural, and physical quantities are provided. The authors treat the nucleation of phase transitions, the production and stability of technologically important metastable phases, and metallic glasses. Furthermore, the text also concisely presents the thermodynamics and composition of polymer systems.

  5. Lattice dynamics and phase diagram of aluminum at high temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Kudasov, Yu. B., E-mail: yu_kudasov@yahoo.com; Surdin, O. M.; Korshunov, A. S.; Pavlov, V. N. [National Research Nuclear University ' MEPhI,' , Sarov State Institute of Physics and Technology (Russian Federation); Frolova, N. V.; Kuzin, R. S. [Russian Federal Nuclear Center-All-Russian Research Institute of Experimental Physics (Russian Federation)

    2013-10-15

    The dispersion of phonons in the fcc, hcp, and bcc phases of aluminum is calculated at ultrahigh pressures by the method of small displacements in a supercell. The stability of the phonon subsystem is studied. The thermodynamic characteristics are calculated in the quasi-harmonic approximation, and a phase diagram of aluminum is plotted. As compared to the Debye model, the use of a phonon spectrum calculated in the quasi-harmonic approximation significantly broadens the hcp phase field and strongly shifts the phase boundary between the fcc and bcc phases. The normal isentrope is calculated at megabar pressures. It is shown to intersect the fcc-hcp and hcp-bcc phase boundaries. The sound velocity along the normal isentrope is calculated. It is shown to have a nonmonotonic character.

  6. Estimating Marginal Returns to Education

    Science.gov (United States)

    Carneiro, Pedro; Heckman, James J.; Vytlacil, Edward

    2011-01-01

    This paper estimates marginal returns to college for individuals induced to enroll in college by different marginal policy changes. The recent instrumental variables literature seeks to estimate this parameter, but in general it does so only under strong assumptions that are tested and found wanting. We show how to utilize economic theory and local instrumental variables estimators to estimate the effect of marginal policy changes. Our empirical analysis shows that returns are higher for individuals with values of unobservables that make them more likely to attend college. We contrast our estimates with IV estimates of the return to schooling. PMID:25110355

  7. Marginal Solutions for the Superstring

    CERN Document Server

    Erler, Theodore

    2007-01-01

    We construct a class of analytic solutions of WZW-type open superstring field theory describing marginal deformations of a reference D-brane background. The deformations we consider are generated by on-shell vertex operators with vanishing operator products. The superstring solution exhibits an intriguing duality with the corresponding marginal solution of the {\\it bosonic} string. In particular, the superstring problem is ``dual'' to the problem of re-expressing the bosonic marginal solution in pure gauge form. This represents the first nonsingular analytic solution of open superstring field theory.

  8. Bifurcation Diagrams and Generalized Bifurcation Diagrams for a rotational model of an oblate satellite

    CERN Document Server

    Tarnopolski, Mariusz

    2013-01-01

    This paper presents bifurcation and generalized bifurcation diagrams for a rotational model of an oblate satellite. Special attention is paid to parameter values describing one of Saturn's moons, Hyperion. For various oblateness the largest Lyapunov Characteristic Exponent (LCE) is plotted. The largest LCE in the initial condition as well as in the mixed parameter-initial condition space exhibits a fractal structure, for which the fractal dimension was calculated. It results from the bifurcation diagrams of which most of the parameter values for preselected initial conditions lead to chaotic rotation. The First Recurrence Time (FRT) diagram provides an explanation of the birth of chaos and the existence of quasi-periodic windows occuring in the bifurcation diagrams.

  9. The political economy of farmers' suicides in India: indebted cash-crop farmers with marginal landholdings explain state-level variation in suicide rates.

    Science.gov (United States)

    Kennedy, Jonathan; King, Lawrence

    2014-03-26

    A recent Lancet article reported the first reliable estimates of suicide rates in India. National-level suicide rates are among the highest in the world, but suicide rates vary sharply between states and the causes of these differences are disputed. We test whether differences in the structure of agricultural production explain inter-state variation in suicides rates. This hypothesis is supported by a large number of qualitative studies, which argue that the liberalization of the agricultural sector in the early-1990s led to an agrarian crisis and that consequently farmers with certain socioeconomic characteristics-cash crops cultivators, with marginal landholdings, and debts-are at particular risk of committing suicide. The recent Lancet study, however, contends that there is no evidence to support this hypothesis. We report scatter diagrams and linear regression models that combine the new state-level suicide rate estimates and the proportion of marginal farmers, cash crop cultivation, and indebted farmers. When we include all variables in the regression equation there is a significant positive relationship between the percentage of marginal farmers, cash crop production, and indebted farmers, and suicide rates. This model accounts for almost 75% of inter-state variation in suicide rates. If the proportion of marginal farmers, cash crops, or indebted farmers were reduced by 1%, the suicide rate--suicides per 100,000 per year--would fall by 0 · 437, 0 · 518 or 0 · 549 respectively, when all other variables are held constant. Even if the Indian state is unable to enact land reforms due to the power of local elites, interventions to stabilize the price of cash crops and relieve indebted farmers may be effective at reducing suicide rates.

  10. A Simple Approach for Boundary Improvement of Euler Diagrams.

    Science.gov (United States)

    Simonetto, Paolo; Archambault, Daniel; Scheidegger, Carlos

    2016-01-01

    General methods for drawing Euler diagrams tend to generate irregular polygons. Yet, empirical evidence indicates that smoother contours make these diagrams easier to read. In this paper, we present a simple method to smooth the boundaries of any Euler diagram drawing. When refining the diagram, the method must ensure that set elements remain inside their appropriate boundaries and that no region is removed or created in the diagram. Our approach uses a force system that improves the diagram while at the same time ensuring its topological structure does not change. We demonstrate the effectiveness of the approach through case studies and quantitative evaluations.

  11. STRUKTURISASI ENTITY RELATIONSHIP DIAGRAM DAN DATA FLOW DIAGRAM BERBASIS BUSINESS EVENT-DRIVEN

    OpenAIRE

    Suroto Adi; Desi Maya Kristin

    2014-01-01

    Entity relationship diagram (ERD) and data flow diagram (DFD) modeling are necessary parts in analysis and design of structured information systems in business. Definition of entities in the ERD, the process, and datastore in the DFD have well described in a lot of literatures. However, practically it is not easy to explain how to design ERD and DFD models so that the students well understand the modeling steps, especially in business applications. This study discussed step-by-step systematic...

  12. ROLE OF UML SEQUENCE DIAGRAM CONSTRUCTS IN OBJECT LIFECYCLE CONCEPT

    Directory of Open Access Journals (Sweden)

    Miroslav Grgec

    2007-06-01

    Full Text Available When modeling systems and using UML concepts, a real system can be viewed in several ways. The RUP (Rational Unified Process defines the "4 + 1 view": 1. Logical view (class diagram (CD, object diagram (OD, sequence diagram (SD, collaboration diagram (COD, state chart diagram (SCD, activity diagram (AD, 2.Process view (use case diagram, CD, OD, SD, COD, SCD, AD, 3. Development view (package diagram, component diagram, 4. Physical view (deployment diagram, and 5. Use case view (use case diagram, OD, SD, COD, SCD, AD which combines the four mentioned above. With sequence diagram constructs we are describing object behavior in scope of one use case and their interaction. Each object in system goes through a so called lifecycle (create, supplement object with data, use object, decommission object. The concept of the object lifecycle is used to understand and formalize the behavior of objects from creation to deletion. With help of sequence diagram concepts our paper will describe the way of interaction modeling between objects through lifeline of each of them, and their importance in software development.

  13. Lyapunov Functions and Solutions of the Lyapunov Matrix Equation for Marginally Stable Systems

    DEFF Research Database (Denmark)

    Kliem, Wolfhard; Pommer, Christian

    2000-01-01

    of the Lyapunov matrix equation and characterize the set of matrices $(B, C)$ which guarantees marginal stability. The theory is applied to gyroscopic systems, to indefinite damped systems, and to circulatory systems, showing how to choose certain parameter matrices to get sufficient conditions for marginal...

  14. Prediction of boron carbon nitrogen phase diagram

    Science.gov (United States)

    Yao, Sanxi; Zhang, Hantao; Widom, Michael

    We studied the phase diagram of boron, carbon and nitrogen, including the boron-carbon and boron-nitrogen binaries and the boron-carbon-nitrogen ternary. Based on the idea of electron counting and using a technique of mixing similar primitive cells, we constructed many ''electron precise'' structures. First principles calculation is performed on these structures, with either zero or high pressures. For the BN binary, our calculation confirms that a rhmobohedral phase can be stablized at high pressure, consistent with some experimental results. For the BCN ternary, a new ground state structure is discovered and an Ising-like phase transition is suggested. Moreover, we modeled BCN ternary phase diagram and show continuous solubility from boron carbide to the boron subnitride phase.

  15. Phase diagram of a single lane roundabout

    Science.gov (United States)

    Echab, H.; Lakouari, N.; Ez-Zahraouy, H.; Benyoussef, A.

    2016-03-01

    Using the cellular automata model, we numerically study the traffic dynamic in a single lane roundabout system of four entry/exit points. The boundaries are controlled by the injecting rates α1, α2 and the extracting rate β. Both the system with and without Splitter Islands of width Lsp are considered. The phase diagram in the (α1 , β) space and its variation with the roundabout size, Pagg (i.e. the probability of aggressive entry), and Pexit (i.e. the probability of preferential exit) are constructed. The results show that the phase diagram in both cases consists of three phases: free flow, congested and jammed. However, as Lsp increases the free flow phase enlarges while the congested and jammed ones shrink. On the other hand, the short sized roundabout shows better performance in the free flow phase while the large one is more optimal in the congested phase. The density profiles are also investigated.

  16. Geometry Helps to Compare Persistence Diagrams

    Energy Technology Data Exchange (ETDEWEB)

    Kerber, Michael; Morozov, Dmitriy; Nigmetov, Arnur

    2015-11-16

    Exploiting geometric structure to improve the asymptotic complexity of discrete assignment problems is a well-studied subject. In contrast, the practical advantages of using geometry for such problems have not been explored. We implement geometric variants of the Hopcroft--Karp algorithm for bottleneck matching (based on previous work by Efrat el al.), and of the auction algorithm by Bertsekas for Wasserstein distance computation. Both implementations use k-d trees to replace a linear scan with a geometric proximity query. Our interest in this problem stems from the desire to compute distances between persistence diagrams, a problem that comes up frequently in topological data analysis. We show that our geometric matching algorithms lead to a substantial performance gain, both in running time and in memory consumption, over their purely combinatorial counterparts. Moreover, our implementation significantly outperforms the only other implementation available for comparing persistence diagrams.

  17. Phase diagram of UCoGe

    Science.gov (United States)

    Mineev, V. P.

    2017-03-01

    The temperature-pressure phase diagram of ferromagnetic superconductor UCoGe includes four phase transitions. They are between the paramagnetic and the ferromagnetic states with the subsequent transition in the superconducting ferromagnetic state and between the normal and the superconducting states after which the transition to the superconducting ferromagnetic state has to occur. Here we have developed the Landau theory description of the phase diagram and established the specific ordering arising at each type of transition. The phase transitions to the ferromagnetic superconducting state are inevitably accompanied by the emergence of screening currents. The corresponding magnetostatics considerations allow for establishing the significant difference between the transition from the ferromagnetic to the ferromagnetic superconducting state and the transition from the superconducting to the ferromagnetic superconducting state.

  18. Flamelet Regime Diagram for Turbulent Combustion Simulations

    Science.gov (United States)

    Chan, Wai Lee; Ihme, Matthias; Kolla, Hemanth; Chen, Jacqueline

    2016-11-01

    The flamelet model has been widely used in numerical combustion investigations, particularly for the closure of large-eddy simulations (LES) of turbulent reacting flows. In most cases, the simulation results demonstrated good agreements with their experimental counterparts. However, a systematic analysis of the flamelet model's applicability, as well as its potential limitations, is seldom conducted, and the model performance is usually based only on a-posteriori comparisons. The objective of this work is to derive a metric that can formally quantify the suitability of the flamelet model in different flame configurations. For this purpose, a flamelet regime diagram has been developed and studied in the context of direct numerical simulations (DNS) of a turbulent lifted jet flame. The implementation of the regime diagram in LES has been investigated through explicit filtering of the DNS results.

  19. Enriched model categories and diagram categories

    CERN Document Server

    Guillou, Bertrand

    2011-01-01

    We collect in one place a variety of known and folklore results in enriched model category theory and add a few new twists. One twist is a new perspective on equivariant model categories. A central theme is a general procedure for constructing a Quillen adjunction, often a Quillen equivalence, between a given V-model category and a category of diagrams in V, where V is any good enriching category. From this perspective, we rederive the result of Schwede and Shipley that reasonable stable model categories are Quillen equivalent to diagram categories of spectra (alias categories of module spectra). The general theory will be applied to G-spectra in a sequel, and for that we need quite a few technical improvements and modifications of general model categorical results. We collect those here. They are bound to have applications in a variety of other contexts.

  20. Worldline Green functions for multiloop diagrams

    CERN Document Server

    Schmidt, M G

    1994-01-01

    We propose a multiloop generalization of the Bern-Kosower formalism, based on Strassler's approach of evaluating worldline path integrals by worldline Green functions. Those Green functions are explicitly constructed for the basic two-loop graph, and for a loop with an arbitrary number of propagator insertions. For scalar and abelian gauge theories, the resulting integral representations allow to combine whole classes of Feynman diagrams into compact expressions.

  1. Disconnected diagrams with twisted-mass fermions

    CERN Document Server

    Abdel-Rehim, Abdou; Constantinou, Martha; Finkenrath, Jacob; Hadjiyiannakou, Kyriakos; Jansen, Karl; Kallidonis, Christos; Koutsou, Giannis; Avilés-Casco, Alejandro Vaquero

    2016-01-01

    The latest results from the Twisted-Mass collaboration on disconnected diagrams at the physical value of the pion mass are presented. In particular, we focus on the sigma terms, the axial charges and the momentum fraction, all of them for the nucleon. A detailed error analysis for each observable follows, showing the strengths and weaknesses of the one-end trick. Alternatives are discussed.

  2. Hydrodynamics of bacterial colonies: Phase diagrams

    Science.gov (United States)

    Lega, J.; Passot, T.

    2004-09-01

    We present numerical simulations of a recent hydrodynamic model describing the growth of bacterial colonies on agar plates. We show that this model is able to qualitatively reproduce experimentally observed phase diagrams, which relate a colony shape to the initial quantity of nutrients on the plate and the initial wetness of the agar. We also discuss the principal features resulting from the interplay between hydrodynamic motions and colony growth, as described by our model.

  3. Mixed wasted integrated program: Logic diagram

    Energy Technology Data Exchange (ETDEWEB)

    Mayberry, J.; Stelle, S. [Science Applications International Corp., Idaho Falls, ID (United States); O`Brien, M. [Univ. of Arizona, Tucson, AZ (United States); Rudin, M. [Univ. of Nevada, Las Vegas, NV (United States); Ferguson, J. [Lockheed Idaho Technologies Co., Idaho Falls, ID (United States); McFee, J. [I.T. Corp., Albuquerque, NM (United States)

    1994-11-30

    The Mixed Waste Integrated Program Logic Diagram was developed to provide technical alternative for mixed wastes projects for the Office of Technology Development`s Mixed Waste Integrated Program (MWIP). Technical solutions in the areas of characterization, treatment, and disposal were matched to a select number of US Department of Energy (DOE) treatability groups represented by waste streams found in the Mixed Waste Inventory Report (MWIR).

  4. Fluctuations and the QCD Phase Diagram

    CERN Document Server

    Koch, Volker

    2016-01-01

    In this contribution we will discuss how the study of various fluctuation observables may be used to explore the phase diagram of the strong interaction. We will briefly summarize the present study of experimental and theoretical research in this area. We will then discuss various corrections and issues which need to be understood and applied for a meaningful comparison of experimental measurements with theoretical predictions. This contribution is dedicated to Andrzej Bialas on the occasion of his $80^{\\mathrm{th}}$ birthday.

  5. On-Shell Diagrams for N = 8 Supergravity Amplitudes

    CERN Document Server

    Heslop, Paul

    2016-01-01

    We define recursion relations for N = 8 supergravity amplitudes using a generalization of the on-shell diagrams developed for planar N = 4 super-Yang-Mills. Although the recursion relations generically give rise to non-planar on-shell diagrams, we show that at tree-level the recursion can be chosen to yield only planar diagrams, the same diagrams occurring in the planar N = 4 theory. This implies non-trivial identities for non-planar diagrams as well as interesting relations between the N = 4 and N = 8 theories. We show that the on-shell diagrams of N = 8 supergravity obey equivalence relations analogous to those of N = 4 super-Yang-Mills, and we develop a systematic algorithm for reading off Grassmannian integral formulae directly from the on-shell diagrams. We also show that the 1-loop 4-point amplitude of N = 8 supergravity can be obtained from on-shell diagrams.

  6. Lectures on configuration space methods for sunrise-type diagrams

    CERN Document Server

    Groote, S

    2003-01-01

    In this lecture series I will give a fundamental insight into configuration space techniques which are of help to calculate a broad class of Feynman diagrams, the sunrise-type diagrams. Applications are shown along with basic concepts and techniques.

  7. Efficient Analysis of Complex Diagrams using Constraint-Based Parsing

    CERN Document Server

    Futrelle, R P; Futrelle, Robert P.; Nikolakis, Nikos

    1995-01-01

    This paper describes substantial advances in the analysis (parsing) of diagrams using constraint grammars. The addition of set types to the grammar and spatial indexing of the data make it possible to efficiently parse real diagrams of substantial complexity. The system is probably the first to demonstrate efficient diagram parsing using grammars that easily be retargeted to other domains. The work assumes that the diagrams are available as a flat collection of graphics primitives: lines, polygons, circles, Bezier curves and text. This is appropriate for future electronic documents or for vectorized diagrams converted from scanned images. The classes of diagrams that we have analyzed include x,y data graphs and genetic diagrams drawn from the biological literature, as well as finite state automata diagrams (states and arcs). As an example, parsing a four-part data graph composed of 133 primitives required 35 sec using Macintosh Common Lisp on a Macintosh Quadra 700.

  8. 75 FR 61512 - Outer Continental Shelf Official Protraction Diagrams

    Science.gov (United States)

    2010-10-05

    ... Bureau of Ocean Energy Management, Regulation and Enforcement Outer Continental Shelf Official... Outer Continental Shelf Official Protraction Diagrams (OPDs) located within Atlantic Ocean areas, with... informational purposes only. Outer Continental Shelf Official Protraction Diagrams in the North Atlantic,...

  9. Linearly recursive sequences and Dynkin diagrams

    CERN Document Server

    Reutenauer, Christophe

    2012-01-01

    Motivated by a construction in the theory of cluster algebras (Fomin and Zelevinsky), one associates to each acyclic directed graph a family of sequences of natural integers, one for each vertex; this construction is called a {\\em frieze}; these sequences are given by nonlinear recursions (with division), and the fact that they are integers is a consequence of the Laurent phenomenon of Fomin and Zelevinsky. If the sequences satisfy a linear recursion with constant coefficients, then the graph must be a Dynkin diagram or an extended Dynkin diagram, with an acyclic orientation. The converse also holds: the sequences of the frieze associated to an oriented Dynkin or Euclidean diagram satisfy linear recursions, and are even $\\mathbb N$-rational. One uses in the proof objects called $SL_2$-{\\em tilings of the plane}, which are fillings of the discrete plane such that each adjacent 2 by 2 minor is equal to 1. These objects, which have applications in the theory of cluster algebras, are interesting for themselves. S...

  10. On diagram-chasing in double complexes

    CERN Document Server

    Bergman, George M

    2011-01-01

    Diagram-chasing arguments frequently lead to "magical" relations between distant points of diagrams: exactness implications, connecting morphisms, etc.. These long connections are usually composites of short "unmagical" connections, but the latter, and the objects they join, are not visible in the proofs. I try to remedy this situation. Given a double complex in an abelian category, we consider, for each object A of the complex, the familiar horizontal and vertical homology objects at A, and two other objects, which we name the "donor" A_{\\box} and and the "receptor" ^{\\box}A at A. For each arrow of the double complex, we prove the exactness of a 6-term sequence of these objects (the "Salamander Lemma"). Standard results such as the 3x3-Lemma, the Snake Lemma, and the long exact sequence of homology associated with a short exact sequence of complexes, are obtained as easy applications of this lemma. We then obtain some generalizations of the last of the above examples, getting various exact diagrams from doub...

  11. Antiferromagnetic phase diagram of the cuprate superconductors

    Science.gov (United States)

    Nunes, L. H. C. M.; Teixeira, A. W.; Marino, E. C.

    2017-02-01

    Taking the spin-fermion model as the starting point for describing the cuprate superconductors, we obtain an effective nonlinear sigma-field hamiltonian, which takes into account the effect of doping in the system. We obtain an expression for the spin-wave velocity as a function of the chemical potential. For appropriate values of the parameters we determine the antiferromagnetic phase diagram for the YBa2Cu3O6+x compound as a function of the dopant concentration in good agreement with the experimental data. Furthermore, our approach provides a unified description for the phase diagrams of the hole-doped and the electron doped compounds, which is consistent with the remarkable similarity between the phase diagrams of these compounds, since we have obtained the suppression of the antiferromagnetic phase as the modulus of the chemical potential increases. The aforementioned result then follows by considering positive values of the chemical potential related to the addition of holes to the system, while negative values correspond to the addition of electrons.

  12. MDM: A Mode Diagram Modeling Framework

    Directory of Open Access Journals (Sweden)

    Zheng Wang

    2012-12-01

    Full Text Available Periodic control systems used in spacecrafts and automotives are usually period-driven and can be decomposed into different modes with each mode representing a system state observed from outside. Such systems may also involve intensive computing in their modes. Despite the fact that such control systems are widely used in the above-mentioned safety-critical embedded domains, there is lack of domain-specific formal modelling languages for such systems in the relevant industry. To address this problem, we propose a formal visual modeling framework called mode diagram as a concise and precise way to specify and analyze such systems. To capture the temporal properties of periodic control systems, we provide, along with mode diagram, a property specification language based on interval logic for the description of concrete temporal requirements the engineers are concerned with. The statistical model checking technique can then be used to verify the mode diagram models against desired properties. To demonstrate the viability of our approach, we have applied our modelling framework to some real life case studies from industry and helped detect two design defects for some spacecraft control systems.

  13. Application of Artificial Neural Network in Indicator Diagram

    Institute of Scientific and Technical Information of China (English)

    WuXiaodong; JiangHua; HanGuoqing

    2004-01-01

    Indicator diagram plays an important role in identifying the production state of oil wells. With an ability to reflect any non-linear mapping relationship, the artificial neural network (ANN) can be used in shape identification. This paper illuminates ANN realization in identifying fault kinds of indicator diagrams, including a back-propagation algorithm, characteristics of the indicator diagram and some examples. It is concluded that the buildup of a neural network and the abstract of indicator diagrams are important to successful application.

  14. Safety-barrier diagrams as a safety management tool

    DEFF Research Database (Denmark)

    Duijm, Nijs Jan

    2009-01-01

    Safety-barrier diagrams and “bow-tie” diagrams have become popular methods in risk analysis and safety management. This paper describes the syntax and principles for constructing consistent and valid safety-barrier diagrams. The latter's relation to other methods such as fault trees and Bayesian...... the management and maintenance of these systems. Safety-barrier diagrams provide a useful framework for an electronic data structure that integrates information from risk analysis with operational safety management....

  15. Geometry Algorisms of Dynkin Diagrams in Lie Group Machine Learning

    Institute of Scientific and Technical Information of China (English)

    Huan Xu; Fanzhang Li

    2006-01-01

    This paper uses the geometric method to describe Lie group machine learning (LML)based on the theoretical framework of LML, which gives the geometric algorithms of Dynkin diagrams in LML. It includes the basic conceptions of Dynkin diagrams in LML ,the classification theorems of Dynkin diagrams in LML, the classification algorithm of Dynkin diagrams in LML and the verification of the classification algorithm with experimental results.

  16. Massive basketball diagram for a thermal scalar field theory

    Science.gov (United States)

    Andersen, Jens O.; Braaten, Eric; Strickland, Michael

    2000-08-01

    The ``basketball diagram'' is a three-loop vacuum diagram for a scalar field theory that cannot be expressed in terms of one-loop diagrams. We calculate this diagram for a massive scalar field at nonzero temperature, reducing it to expressions involving three-dimensional integrals that can be easily evaluated numerically. We use this result to calculate the free energy for a massive scalar field with a φ4 interaction to three-loop order.

  17. The role of perceptual cues in matrix diagrams

    NARCIS (Netherlands)

    van der Meij, Jan; van Amelsvoort, Marije; Anjewierden, A.

    2015-01-01

    An experiment was conducted to assess whether the design of a matrix diagram influences how people study the diagram and whether this has an effect on recall of the presented information. We compared four versions of a matrix diagram on antisocial personality disorder. It consisted of four header ce

  18. Developing Tool Support for Problem Diagrams with CPN and VDM++

    DEFF Research Database (Denmark)

    Tjell, Simon; Lassen, Kristian Bisgaard

    2008-01-01

    In this paper, we describe ongoing work on the development of tool support for formal description of domains found in Problem Diagrams. The purpose of the tool is to handle the generation of a CPN model based on a collection of Problem Diagrams. The Problem Diagrams are used for representing the ...

  19. The role of perceptual cues in matrix diagrams

    NARCIS (Netherlands)

    van der Meij, Jan; Amelsvoort, Marije; Anjewierden, Anjo Allert

    2015-01-01

    An experiment was conducted to assess whether the design of a matrix diagram influences how people study the diagram and whether this has an effect on recall of the presented information. We compared four versions of a matrix diagram on antisocial personality disorder. It consisted of four header

  20. The role of perceptual cues in matrix diagrams

    NARCIS (Netherlands)

    van der Meij, Jan; van Amelsvoort, Marije; Anjewierden, A.

    An experiment was conducted to assess whether the design of a matrix diagram influences how people study the diagram and whether this has an effect on recall of the presented information. We compared four versions of a matrix diagram on antisocial personality disorder. It consisted of four header

  1. [Sinaloa: the geography of marginalization].

    Science.gov (United States)

    Aguayo Hernandez, J R

    1993-01-01

    Sinaloa's State Population Program for 1993-98 contains the objective of promoting integration of demographic criteria into the planning process. The action program calls for establishing indicators of economic and social inequality so that conditions of poverty and margination can be identified. To further these goals, the State Population Council used data from the National Population Council project on regional inequality and municipal margination in Mexico to analyze margination at the state level. Nine indicators of educational status, housing conditions, spatial distribution, and income provide information that allows the definition of municipios and regions that should receive priority in economic and social development programs. The index of municipal margination (IMM) is a statistical summary of the nine indicators, which are based on information in the 1990 census. As of March 1990, 9.9% of Sinaloa's population over age 15 was illiterate and 37.4% had incomplete primary education. 91.0% had electricity, but 18.7% lacked indoor toilet facilities and 19.4% had no piped water. 23.7% of houses had dirt floors. 60% of households were crowded, defined as having more than two persons per bedroom. 43.5% of the state population lived in localities with fewer than 5000 inhabitants, where service delivery is difficult and costly. 55.6% of the economically active population was judged to earn less than the amount needed to satisfy essential needs. All except one municipio bordering the Pacific ocean had low or very low indicators of margination, while all those in the sierra had a medium or high degree of margination. Sinaloa's statewide IMM was eighteenth among Mexico's 32 federal entities, with Chiapas showing the highest degree of margination and the Federal District the lowest.

  2. Computing phase diagrams for a quasicrystal-forming patchy-particle system.

    Science.gov (United States)

    Reinhardt, Aleks; Romano, Flavio; Doye, Jonathan P K

    2013-06-21

    We introduce an approach to computing the free energy of quasicrystals, which we use to calculate phase diagrams for systems of two-dimensional patchy particles with five regularly arranged patches that have previously been shown to form dodecagonal quasicrystals. We find that the quasicrystal is a thermodynamically stable phase for a wide range of conditions and remains a robust feature of the system as the potential's parameters are varied. We also demonstrate that the quasicrystal is entropically stabilized over its crystalline approximants.

  3. Maximum margin Bayesian network classifiers.

    Science.gov (United States)

    Pernkopf, Franz; Wohlmayr, Michael; Tschiatschek, Sebastian

    2012-03-01

    We present a maximum margin parameter learning algorithm for Bayesian network classifiers using a conjugate gradient (CG) method for optimization. In contrast to previous approaches, we maintain the normalization constraints on the parameters of the Bayesian network during optimization, i.e., the probabilistic interpretation of the model is not lost. This enables us to handle missing features in discriminatively optimized Bayesian networks. In experiments, we compare the classification performance of maximum margin parameter learning to conditional likelihood and maximum likelihood learning approaches. Discriminative parameter learning significantly outperforms generative maximum likelihood estimation for naive Bayes and tree augmented naive Bayes structures on all considered data sets. Furthermore, maximizing the margin dominates the conditional likelihood approach in terms of classification performance in most cases. We provide results for a recently proposed maximum margin optimization approach based on convex relaxation. While the classification results are highly similar, our CG-based optimization is computationally up to orders of magnitude faster. Margin-optimized Bayesian network classifiers achieve classification performance comparable to support vector machines (SVMs) using fewer parameters. Moreover, we show that unanticipated missing feature values during classification can be easily processed by discriminatively optimized Bayesian network classifiers, a case where discriminative classifiers usually require mechanisms to complete unknown feature values in the data first.

  4. A simple, universal theory and method for computer plotting of stable equilibrium phase diagrams of a multisystem SFM method

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A new easy method has been presented to calculate the variable intervals corresponding to the stable univariant curves and to discriminate the stabilities of invariant points. This method and the one reported previously constitute a simple and universal theory for the computer-plotting of the equilibrium phase diagrams of a multisystem sign function matrix (SFM) discrimination method. Its main steps are: determining the stable univariant scheme according to the derivative (or difference) of ΔrGm; grouping the univariant curves by comparisons of the mutual relations among them; determining the existing intervals of the variables for the stable curves by comparisons of coordinate values of the curves about the invariant point; determining the stabilities of invariant points by comparisons of relations between the common curves and the invariant points. This method is suitable for any kind of phase diagram of closed or open systems in a phase diagram "space" with either 2 or more than 2 dimensions.

  5. An automatic layout system for OMT-based object diagram

    Energy Technology Data Exchange (ETDEWEB)

    Nakashima, Satoshi; Ali, Jauhar; Tanaka, Jiro [Univ. of Tsukuba (Japan)

    1996-12-31

    In this paper, we propose an automatic layout method for the object diagram, the event trace diagram and the state diagram based on OMT (Object Modeling Technique) methodology. In our automatic layout system, when the elements of model (classes, associations etc.) are entered, an arrangement for them is computed, and the object model automatically appears in the editor`s window. We adopted Messinger`s algorithm using the rule of divide-and-conquer for the layout algorithm of the object diagram. Furthermore, diagrams can be maintained easily with the capabilities of automatic modification and direct manipulation interface.

  6. Comprehending 3D Diagrams: Sketching to Support Spatial Reasoning.

    Science.gov (United States)

    Gagnier, Kristin M; Atit, Kinnari; Ormand, Carol J; Shipley, Thomas F

    2016-11-25

    Science, technology, engineering, and mathematics (STEM) disciplines commonly illustrate 3D relationships in diagrams, yet these are often challenging for students. Failing to understand diagrams can hinder success in STEM because scientific practice requires understanding and creating diagrammatic representations. We explore a new approach to improving student understanding of diagrams that convey 3D relations that is based on students generating their own predictive diagrams. Participants' comprehension of 3D spatial diagrams was measured in a pre- and post-design where students selected the correct 2D slice through 3D geologic block diagrams. Generating sketches that predicated the internal structure of a model led to greater improvement in diagram understanding than visualizing the interior of the model without sketching, or sketching the model without attempting to predict unseen spatial relations. In addition, we found a positive correlation between sketched diagram accuracy and improvement on the diagram comprehension measure. Results suggest that generating a predictive diagram facilitates students' abilities to make inferences about spatial relationships in diagrams. Implications for use of sketching in supporting STEM learning are discussed.

  7. Magnetic AP Stars in the Hertzsprung-Russell Diagram

    Science.gov (United States)

    Hubrig, S.; North, P.; Mathys, G.

    2000-08-01

    The evolutionary state of magnetic Ap stars is rediscussed using the recently released Hipparcos data. The distribution of the magnetic Ap stars of mass below 3 Msolar in the H-R diagram differs from that of the normal stars in the same temperature range at a high level of significance. Magnetic stars are concentrated toward the center of the main-sequence band. This is shown in two forms of the H-R diagram: one where logL is plotted against logTeff and a version more directly tied to the observed quantities, showing the astrometry-based luminosity (Arenou & Luri) against the (B2-G)0 index of Geneva photometry. In particular, it is found that magnetic fields appear only in stars that have already completed at least approximately 30% of their main-sequence lifetime. No clear picture emerges as to the possible evolution of the magnetic field across the main sequence. Hints of some (loose) relations between magnetic field strength and other stellar parameters are found: stars with shorter periods tend to have stronger fields, as do higher temperature and higher mass stars. A marginal trend of the magnetic flux to be lower in more slowly rotating stars may possibly be seen as suggesting a dynamo origin for the field. No correlation between the rotation period and the fraction of the main-sequence lifetime completed is observed, indicating that the slow rotation in these stars must already have been achieved before they became observably magnetic. Based on data from the ESA Hipparcos satellite and on observations collected at the European Southern Observatory (La Silla, Chile; ESO programs Nos. 43.7-004, 44.7-012, 49.7-030, 50.7-067, 51.7-041, 52.7-063, 53.7-028, 54.E-0416, and 55.E-0751), at the Observatoire de Haute-Provence (Saint-Michel l'Observatoire, France), at Kitt Peak National Observatory, and at the Canada-France-Hawaii Telescope.

  8. Design and Realization of Numerical Control Ladder Diagram Edition Software

    Institute of Scientific and Technical Information of China (English)

    ZHAO Haixin; MO Yimin; PAN Yunping

    2006-01-01

    The thesis is directed by the idea of oriented- object. Considering the basic functions that NC system Ladder Diagram editor should provide, and through theoretical research and practice, the thesis developed a set of NC system Ladder Diagram editor which can form a Ladder Diagram editor based on vector plotting, intelligently compiling, simulation. This system uses the ladder diagram symbol to express operational order and use the chart symbol series-parallel connection and the position order to express the logical relations between the operational orders, divide the ladder diagram into four parts: the stave, the line, the row and the part, uses the standard order vessel list vessel of the standard template stack (STL) to save the data which involved in the design process. This system can write PLC program by ladder diagram language and is easy to use. The compilation and simulation for PLC diagram have been achieved. It greatly improves the work-efficiency.

  9. State-transition diagrams for biologists.

    Science.gov (United States)

    Bersini, Hugues; Klatzmann, David; Six, Adrien; Thomas-Vaslin, Véronique

    2012-01-01

    It is clearly in the tradition of biologists to conceptualize the dynamical evolution of biological systems in terms of state-transitions of biological objects. This paper is mainly concerned with (but obviously not limited too) the immunological branch of biology and shows how the adoption of UML (Unified Modeling Language) state-transition diagrams can ease the modeling, the understanding, the coding, the manipulation or the documentation of population-based immune software model generally defined as a set of ordinary differential equations (ODE), describing the evolution in time of populations of various biological objects. Moreover, that same UML adoption naturally entails a far from negligible representational economy since one graphical item of the diagram might have to be repeated in various places of the mathematical model. First, the main graphical elements of the UML state-transition diagram and how they can be mapped onto a corresponding ODE mathematical model are presented. Then, two already published immune models of thymocyte behavior and time evolution in the thymus, the first one originally conceived as an ODE population-based model whereas the second one as an agent-based one, are refactored and expressed in a state-transition form so as to make them much easier to understand and their respective code easier to access, to modify and run. As an illustrative proof, for any immunologist, it should be possible to understand faithfully enough what the two software models are supposed to reproduce and how they execute with no need to plunge into the Java or Fortran lines.

  10. Crustal thinning and tectonic geomorphology: redefining the passive margin

    Science.gov (United States)

    Redfield, T.; Osmundsen, P. T.

    2012-04-01

    engendered by isostatically-induced flexure. Fault reactivation in the inner proximal margin may contribute to stabilize the location of the escarpment over time at sharply tapering margins. In this model the principal driver behind accomodation is the shifting of loads that commenced during the main phases of rifting and that has continued to present day.

  11. Ideal MHD stability of very high beta tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Chance, M.S.; Jardin, S.C.; Kessel, C.; Manickam, J.; Monticello, D. (Princeton Univ., NJ (USA). Plasma Physics Lab.); Peng, Y.K.M.; Holmes, J.A.; Strickler, D.J.; Whitson, J.C. (Oak Ridge National Lab., TN (USA)); Glasser, A.H. (Los Alamos National Lab., NM (USA)); Sykes, A. (UKAEA Culham Lab., Abingdon (UK)); Ramos, J.J. (Massachusetts Inst. of Tech., Cambridge, MA (USA). Plasma Fusion Center)

    1990-12-01

    Achieving very high {beta} and high {beta}{sub p} simultaneously in tokamaks generally implies that the second stability region against ballooning modes must be accessed. We describe several approaches for doing this, which are characterized by the choice of constraints imposed on the equilibrium profiles and the cross-sectional shape of the plasma. The combination of high toroidal beta, restricting the current density to vanish at the edge of the plasma and maintaining a monotonic q profile, proves to be the most stringent. Consideration of equilibria with high {epsilon}{beta}{sub p} but low {beta} facilitates accessibility with peaked pressure profiles and high values of q{sub 0}. Allowing the pressure gradient and, hence, the current density to be finite at the plasma edge allows all surfaces to lie within the second stability regime. For free boundary plasmas with divertors, the divertor stabilized edge region remains in the first stability regime while the plasma core reaches into the second regime. Careful tailoring of the profiles must be used to traverse the unstable barrier commonly seen near the edge of these plasmas. The CAMINO code allows us to compute s-{alpha} curves for general tokamak geometry. These diagrams enable us to construct equilibria whose profiles are only constrained, at worst, to be marginally stable everywhere, but do not necessarily satisfy the constraints on the current or {beta}. There are theoretical indications that under certain conditions the external kinks possess a second region of stability at high q{sub 0} that is analogous to that of the ballooning modes. It is found that extremely accurate numerical means must be developed and applied to confidently establish the validity of these results. 14 refs., 5 figs., 1 tab.

  12. Algorithms for Disconnected Diagrams in Lattice QCD

    Energy Technology Data Exchange (ETDEWEB)

    Gambhir, Arjun Singh [College of William and Mary, Williamsburg, VA (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Stathopoulos, Andreas [College of William and Mary, Williamsburg, VA (United States); Orginos, Konstantinos [College of William and Mary, Williamsburg, VA (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Yoon, Boram [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gupta, Rajan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Syritsyn, Sergey [Stony Brook Univ., NY (United States)

    2016-11-01

    Computing disconnected diagrams in Lattice QCD (operator insertion in a quark loop) entails the computationally demanding problem of taking the trace of the all to all quark propagator. We first outline the basic algorithm used to compute a quark loop as well as improvements to this method. Then, we motivate and introduce an algorithm based on the synergy between hierarchical probing and singular value deflation. We present results for the chiral condensate using a 2+1-flavor clover ensemble and compare estimates of the nucleon charges with the basic algorithm.

  13. On critical exponents without Feynman diagrams

    Science.gov (United States)

    Sen, Kallol; Sinha, Aninda

    2016-11-01

    In order to achieve a better analytic handle on the modern conformal bootstrap program, we re-examine and extend the pioneering 1974 work of Polyakov’s, which was based on consistency between the operator product expansion and unitarity. As in the bootstrap approach, this method does not depend on evaluating Feynman diagrams. We show how this approach can be used to compute the anomalous dimensions of certain operators in the O(n) model at the Wilson-Fisher fixed point in 4-ɛ dimensions up to O({ɛ }2). AS dedicates this work to the loving memory of his mother.

  14. Magnetic phase diagram of Ho-Ag

    Energy Technology Data Exchange (ETDEWEB)

    Paul-Boncour, V [Chimie Metallurgique des Terres Rares, ICMPE, CNRS, 2 rue H Dunant, 94320 Thiais (France); Hoser, A; Stuesser, N [Hahn-Meitner Institut, Glienicker Strasse 100, 14109, Berlin (Germany); Hense, K; Gratz, E [Institute for Experimental Physics, Technical University Vienna, Wiedner Hauptstrasse 8-10, A-1040 (Austria); Rotter, M [Institut fuer Physikalische Chemie, Universitaet Wien, Waehringerstrasse 42, 1090 Wien (Austria)], E-mail: paulbon@glvt-cnrs.fr

    2008-03-12

    The magnetic phase diagram of Ho-Ag has been established using magnetoresistance, magnetostriction and neutron diffraction experiments versus applied field and temperature. Three different magnetic phases were observed: an incommensurate antiferromagnetic phase (IC) below T{sub N} = 33 K, a commensurate antiferromagnetic phase (C) above 5 T and below T{sub 1} (5-8 K) and a ferromagnetic component above 3 T. The IC phase undergoes spin reorientations around 5 T (IC') and 13 T (IC'')

  15. On critical exponents without Feynman diagrams

    CERN Document Server

    Sen, Kallol

    2015-01-01

    In order to achieve a better analytic handle on the modern conformal bootstrap program, we re-examine and extend the pioneering 1974 work of Polyakov's, which was based on consistency between the operator product expansion and unitarity. As in the bootstrap approach, this method does not depend on evaluating Feynman diagrams. We show how this approach can be used to compute the anomalous dimensions of certain operators in the $O(n)$ model at the Wilson-Fisher fixed point in $4-\\epsilon$ dimensions up to $O(\\epsilon^2)$.

  16. Applications of zero-suppressed decision diagrams

    CERN Document Server

    Sasao, Tsutomu

    2014-01-01

    A zero-suppressed decision diagram (ZDD) is a data structure to represent objects that typically contain many zeros. Applications include combinatorial problems, such as graphs, circuits, faults, and data mining. This book consists of four chapters on the applications of ZDDs. The first chapter by Alan Mishchenko introduces the ZDD. It compares ZDDs to BDDs, showing why a more compact representation is usually achieved in a ZDD. The focus is on sets of subsets and on sum-of-products (SOP) expressions. Methods to generate all the prime implicants (PIs), and to generate irredundant SOPs are show

  17. Algorithms for Disconnected Diagrams in Lattice QCD

    CERN Document Server

    Gambhir, Arjun Singh; Orginos, Kostas; Yoon, Boram; Gupta, Rajan; Syritsyn, Sergey

    2016-01-01

    Computing disconnected diagrams in Lattice QCD (operator insertion in a quark loop) entails the computationally demanding problem of taking the trace of the all to all quark propagator. We first outline the basic algorithm used to compute a quark loop as well as improvements to this method. Then, we motivate and introduce an algorithm based on the synergy between hierarchical probing and singular value deflation. We present results for the chiral condensate using a 2+1-flavor clover ensemble and compare estimates of the nucleon charges with the basic algorithm.

  18. Failure Assessment Diagram for Titanium Brazed Joints

    Science.gov (United States)

    Flom, Yury; Jones, Justin S.; Powell, Mollie M.; Puckett, David F.

    2011-01-01

    The interaction equation was used to predict failure in Ti-4V-6Al joints brazed with Al 1100 filler metal. The joints used in this study were geometrically similar to the joints in the brazed beryllium metering structure considered for the ATLAS telescope. This study confirmed that the interaction equation R(sub sigma) + R(sub Tau) = 1, where R(sub sigma) and R(sub Tau)are normal and shear stress ratios, can be used as conservative lower bound estimate of the failure criterion in ATLAS brazed joints as well as for construction of the Failure Assessment Diagram (FAD).

  19. Spectral Transforms Calculation through Decision Diagrams

    Directory of Open Access Journals (Sweden)

    Radomir S. Stanković

    2002-01-01

    Full Text Available In this paper, calculation of spectral transforms through Decision diagrams (DDs and relationship of this method with FFT-like algorithms is discussed. It is shown that in DDs methods the basic operations in FFT-like algorithms are performed not on vectors but instead on parts of DDs as a data structure. Such a data structure represents the input signals, the intermediate results obtained during the calculation as well as the final output results. It should be noticed that, unlike FFT-like algorithms, DDs methods permit to take advantages from both, the properties of the transform matrices and the particular properties of the processed signals.

  20. High temperature phase equilibria and phase diagrams

    CERN Document Server

    Kuo, Chu-Kun; Yan, Dong-Sheng

    2013-01-01

    High temperature phase equilibria studies play an increasingly important role in materials science and engineering. It is especially significant in the research into the properties of the material and the ways in which they can be improved. This is achieved by observing equilibrium and by examining the phase relationships at high temperature. The study of high temperature phase diagrams of nonmetallic systems began in the early 1900s when silica and mineral systems containing silica were focussed upon. Since then technical ceramics emerged and more emphasis has been placed on high temperature

  1. Combinatorics of Link Diagrams and Volume

    OpenAIRE

    Giambrone, Adam

    2013-01-01

    We show that the volumes of certain hyperbolic A-adequate links can be bounded (above and) below in terms of two diagrammatic quantities: the twist number and the number of certain alternating tangles in an A-adequate diagram. We then restrict our attention to plat closures of certain braids, a rich family of links whose volumes can be bounded in terms of the twist number alone. Furthermore, in the absence of special tangles, our volume bounds can be expressed in terms of a single stable coef...

  2. A comparative study of linear and region based diagrams

    Directory of Open Access Journals (Sweden)

    Björn Gottfried

    2015-06-01

    Full Text Available There are two categories of objects spatial information science investigates: actual objects and their spatial properties, such as in geography, and abstract objects which are employed metaphorically, as for visual languages. A prominent example of the latter are diagrams that model knowledge of some domain. Different aspects of diagrams are of interest, including their formal properties or how human users work with them, for example, with diagrams representing sets. The literature about diagrammatic systems for the representation of sets shows a dominance of region-based diagrams like Euler circles and Venn diagrams. The effectiveness of these diagrams, however, is limited because region-based diagrams become quite complex for more then three sets. By contrast, linear diagrams are not equally prevalent but enable the representation of a greater number of sets without getting cluttered. Cluttered diagrams exhibit inherent complexity due to overlapping objects, irrelevant details, or other reasons that impinge upon their legibility. This study contrasts both types of diagrammatic systems and investigates whether the performance of users differs for both kinds of diagrams. A significant difference can be shown regarding the number of diagrams that can be drawn within a fixed period of time and regarding the number of errors made. The results indicate that linear diagrams are more effective by being more restrictive and because region based diagrams show much clutter due to overlapping, coincident, and tangentially touching contours, as well as an overwhelming number of empty zones. Linear diagrams are less prone to errors and do not suffer from clutter.

  3. On the Dynamic Stability of a Missile

    Directory of Open Access Journals (Sweden)

    K.C. Sharma

    1977-01-01

    Full Text Available The P-method given by Parks and Pritchard has been used to discuss the stability behaviour of a missile in free flight. General stability criteria for aerodynamic stabilisation have been obtained for slowly varying coefficients. The effect of pressure gradient on the stability of a coasting rocket has been explicitly examined. It is observed that the positive Magnus moment parameter ensures stability whereas a negative moment parameter would enhance the requirements of a larger stability margin.

  4. The effect of four-spin exchanges on the honeycomb lattice diagram phase of S=3/2 J1-J2 Antiferromagnetic Heisenberg model

    Directory of Open Access Journals (Sweden)

    F Keshavarz

    2017-02-01

    Full Text Available In this study, the effect of four-spin exchanges between the nearest and next nearest neighbor spins of honeycomb lattice on the phase diagram of S=3/2 antiferomagnetic Heisenberg model is considered with two-spin exchanges between the nearest and next nearest neighbor spins. Firstly, the method is investigated with classical phase diagram. In classical phase diagram, in addition to Neel order, classical degeneracy is also seen. The existance of this phase in diagram phase is important because of the probability of the existence of quantum spin liquid in this region for such amount of interaction. To investigate the effect of quantum fluctuation on the stability of the obtained classical phase diagram, linear spin wave theory has been used. Obtained results show that in classical degeneracy regime, the quantum fluctuations cause the order by disorder in the spin system and the ground state is ordered

  5. Fluctuation-stabilized marginal networks and anomalous entropic elasticity.

    Science.gov (United States)

    Dennison, M; Sheinman, M; Storm, C; MacKintosh, F C

    2013-08-30

    We study the elastic properties of thermal networks of Hookean springs. In the purely mechanical limit, such systems are known to have a vanishing rigidity when their connectivity falls below a critical, isostatic value. In this work, we show that thermal networks exhibit a nonzero shear modulus G well below the isostatic point and that this modulus exhibits an anomalous, sublinear dependence on temperature T. At the isostatic point, G increases as the square root of T, while we find G∝Tα below the isostatic point, where α≃0.8. We show that this anomalous T dependence is entropic in origin.

  6. Profit margins in Japanese retailing

    NARCIS (Netherlands)

    J.C.A. Potjes; A.R. Thurik (Roy)

    1993-01-01

    textabstractUsing a rich data source, we explain differences and developments in profit margins of medium-sized stores in Japan. We conclude that the protected environment enables the retailer to pass on all operating costs to the customers and to obtain a relatively high basic income. High service

  7. Profit margins in Japanese retailing

    NARCIS (Netherlands)

    J.C.A. Potjes; A.R. Thurik (Roy)

    1993-01-01

    textabstractUsing a rich data source, we explain differences and developments in profit margins of medium-sized stores in Japan. We conclude that the protected environment enables the retailer to pass on all operating costs to the customers and to obtain a relatively high basic income. High service

  8. Respiration in ocean margin sediments

    NARCIS (Netherlands)

    Andersson, J.H.

    2007-01-01

    The aim of this thesis was the study of respiration in ocean margin sediments and the assessments of tools needed for this purpose. The first study was on the biological pump and global respiration patterns in the deep ocean using an empirical model based on sediment oxygen consumption data. In this

  9. Respiration in ocean margin sediments

    NARCIS (Netherlands)

    Andersson, J.H.

    2007-01-01

    The aim of this thesis was the study of respiration in ocean margin sediments and the assessments of tools needed for this purpose. The first study was on the biological pump and global respiration patterns in the deep ocean using an empirical model based on sediment oxygen consumption data.

  10. Kinematical Diagrams for Conical Relativistic Jets

    Indian Academy of Sciences (India)

    Gopal-Krishna; Pronoy Sircar; Samir Dhurde

    2007-03-01

    We present diagrams depicting the expected inter-dependences of two key kinematical parameters of radio knots in the parsec-scale jets of blazars, deduced from VLBI observations. The two parameters are the apparent speed (app = capp) and the effective Doppler boosting factor (eff) of the relativistically moving radio knot. A novel aspect of these analytical computations of – diagrams is that they are made for parsecscale jets having a conical shape, with modest opening angles ( up to 10°), in accord with the VLBI observations of the nuclei of the nearest radio galaxies. Another motivating factor is the recent finding that consideration of a conical geometry can have important implications for the interpretation of a variety of radio observations of blazar jets. In addition to uniform jet flows (i.e., those having a uniform bulk Lorentz factor, ), computational results are also presented for stratified jets where an ultra-relativistic central spine along the jet axis is surrounded by a slower moving sheath, possibly arising from a velocity shear.

  11. The Critical Importance of Russell's Diagram

    CERN Document Server

    Gingerich, Owen

    2013-01-01

    The idea of dwarf and giants stars, but not the nomenclature, was first established by Eijnar Hertzsprung in 1905; his first diagrams in support appeared in 1911. In 1913 Henry Norris Russell could demonstrate the effect far more strikingly because he measured the parallaxes of many stars at Cambridge, and could plot absolute magnitude against spectral type for many points. The general concept of dwarf and giant stars was essential in the galactic structure work of Harlow Shapley, Russell's first graduate student. In order to calibrate the period-luminosity relation of Cepheid variables, he was obliged to fall back on statistical parallax using only 11 Cepheids, a very sparse sample. Here the insight provided by the Russell diagram became critical. The presence of yellow K giant stars in globular clusters credentialed his calibration of the period-luminosity relation by showing that the calibrated luminosity of the Cepheids was comparable to the luminosity of the K giants. It is well known that in 1920 Shaple...

  12. Phase diagram of twisted mass lattice QCD

    Science.gov (United States)

    Sharpe, Stephen R.; Wu, Jackson M.

    2004-11-01

    We use the effective chiral Lagrangian to analyze the phase diagram of two-flavor twisted mass lattice QCD as a function of the normal and twisted masses, generalizing previous work for the untwisted theory. We first determine the chiral Lagrangian including discretization effects up to next-to-leading order (NLO) in a combined expansion in which m2π/(4πfπ)2˜aΛ (a being the lattice spacing, and Λ=ΛQCD). We then focus on the region where m2π/(4πfπ)2˜(aΛ)2, in which case competition between leading and NLO terms can lead to phase transitions. As for untwisted Wilson fermions, we find two possible phase diagrams, depending on the sign of a coefficient in the chiral Lagrangian. For one sign, there is an Aoki phase for pure Wilson fermions, with flavor and parity broken, but this is washed out into a crossover if the twisted mass is nonvanishing. For the other sign, there is a first order transition for pure Wilson fermions, and we find that this transition extends into the twisted mass plane, ending with two symmetrical second order points at which the mass of the neutral pion vanishes. We provide graphs of the condensate and pion masses for both scenarios, and note a simple mathematical relation between them. These results may be of importance to numerical simulations.

  13. Ab initio phase diagram of iridium

    Science.gov (United States)

    Burakovsky, L.; Burakovsky, N.; Cawkwell, M. J.; Preston, D. L.; Errandonea, D.; Simak, S. I.

    2016-09-01

    The phase diagram of iridium is investigated using the Z methodology. The Z methodology is a technique for phase diagram studies that combines the direct Z method for the computation of melting curves and the inverse Z method for the calculation of solid-solid phase boundaries. In the direct Z method, the solid phases along the melting curve are determined by comparing the solid-liquid equilibrium boundaries of candidate crystal structures. The inverse Z method involves quenching the liquid into the most stable solid phase at various temperatures and pressures to locate a solid-solid boundary. Although excellent agreement with the available experimental data (to ≲65 GPa) is found for the equation of state (EOS) of Ir, it is the third-order Birch-Murnaghan EOS with B0'=5 rather than the more widely accepted B0'=4 that describes our ab initio data to higher pressure (P ) . Our results suggest the existence of a random-stacking hexagonal close-packed structure of iridium at high P . We offer an explanation for the 14-layer hexagonal structure observed in experiments by Cerenius and Dubrovinsky.

  14. Phase diagram of quantum square ice

    Science.gov (United States)

    Henry, Louis-Paul; Holdsworth, Peter; Mila, Frederic; Roscilde, Tommaso

    2013-03-01

    We have investigated the ground-state and finite-temperature phase diagram of quantum square ice - realized by the transverse-field Ising model on a checkerboard lattice - using both linear spin-wave (LSW) theory and quantum Monte Carlo (QMC). We generalize the model with different couplings between nearest (J1) and next-to-nearest (J2) neighbors on the checkerboard lattice. Our QMC approach generalizes the loop algorithm - very efficient in the study of constrained classical systems - to a ``brane algorithm'' for quantum systems. At the LSW level the vast degeneracy of the ground-state for J1 =J2 and J2 >J1 remains intact; moreover LSW theory breaks down in extended regions of the phase diagram, pointing at non-classical states. Our QMC study goes beyond perturbative schemes and addresses directly the nature of the low-temperature phases. We have critically examined the possibility of a resonating-plaquette state for J1 =J2 , suggested by degenerate perturbation theory on the ice-rule manifold for weak fields. Our QMC results for finite fields confirm the absence of Néel or collinear order, but they do not confirm the presence of resonating-plaquette order, pointing at a possibly more complex non-classical state.

  15. The magnetized effective QCD phase diagram

    CERN Document Server

    Ayala, Alejandro; Hernandez, L A; Loewe, M; Zamora, R

    2015-01-01

    The QCD phase diagram in the temperature versus quark chemical potential plane is studied in the presence of a magnetic field, using the linear sigma model coupled to quarks. It is shown that the decrease of the couplings with increasing field strength obtained in this model leads to the critical temperature for the phase transition to decrease with increasing field intensity (inverse magnetic catalysis). This happens provided that plasma screening is properly accounted for. It is also found that with increasing field strength the location of the critical end point (CEP) in the phase diagram moves toward lower values of the critical quark chemical potential and larger values of the critical temperature. In addition, the CEP approaches the temperature axis for large values of the magnetic field. We argue that a similar behavior is to be expected in QCD, since the physical impact of the magnetic field, regardless of strength, is to produce a spatial dimension reduction, whereby virtual quark-antiquark pairs are...

  16. Reliability block diagrams to model disease management.

    Science.gov (United States)

    Sonnenberg, A; Inadomi, J M; Bauerfeind, P

    1999-01-01

    Studies of diagnostic or therapeutic procedures in the management of any given disease tend to focus on one particular aspect of the disease and ignore the interaction between the multitude of factors that determine its final outcome. The present article introduces a mathematical model that accounts for the joint contribution of various medical and non-medical components to the overall disease outcome. A reliability block diagram is used to model patient compliance, endoscopic screening, and surgical therapy for dysplasia in Barrett's esophagus. The overall probability of a patient with a Barrett's esophagus to comply with a screening program, be correctly diagnosed with dysplasia, and undergo successful therapy is 37%. The reduction in the overall success rate, despite the fact that the majority of components are assumed to function with reliability rates of 80% or more, is a reflection of the multitude of serial subsystems involved in disease management. Each serial component influences the overall success rate in a linear fashion. Building multiple parallel pathways into the screening program raises its overall success rate to 91%. Parallel arrangements render systems less sensitive to diagnostic or therapeutic failures. A reliability block diagram provides the means to model the contributions of many heterogeneous factors to disease outcome. Since no medical system functions perfectly, redundancy provided by parallel subsystems assures a greater overall reliability.

  17. Phase Diagram of Spiking Neural Networks

    Directory of Open Access Journals (Sweden)

    Hamed eSeyed-Allaei

    2015-03-01

    Full Text Available In computer simulations of spiking neural networks, often it is assumed that every two neurons of the network are connected by a probablilty of 2%, 20% of neurons are inhibitory and 80% are excitatory. These common values are based on experiments, observations. but here, I take a different perspective, inspired by evolution. I simulate many networks, each with a different set of parameters, and then I try to figure out what makes the common values desirable by nature. Networks which are configured according to the common values, have the best dynamic range in response to an impulse and their dynamic range is more robust in respect to synaptic weights. In fact, evolution has favored networks of best dynamic range. I present a phase diagram that shows the dynamic ranges of different networks of different parameteres. This phase diagram gives an insight into the space of parameters -- excitatory to inhibitory ratio, sparseness of connections and synaptic weights. It may serve as a guideline to decide about the values of parameters in a simulation of spiking neural network.

  18. A non-equilibrium state diagram for liquid/fluid/particle mixtures.

    Science.gov (United States)

    Velankar, Sachin S

    2015-11-21

    The equilibrium structures of ternary oil/water/surfactant systems are often represented within a triangular composition diagram with various regions of the triangle corresponding to different equilibrium states. We transplant this idea to ternary liquid/fluid/particle systems that are far from equilibrium. Liquid/liquid/particle mixtures or liquid/gas/particle mixtures yield a wide diversity of morphologies including Pickering emulsions, bijels, pendular aggregates, spherical agglomerates, capillary suspensions, liquid marbles, powdered liquids, and particle-stabilized foams. This paper argues that such ternary liquid/fluid/particle mixtures can be unified into a non-equilibrium state diagram. What is common among all these systems is that the morphology results from an interplay between the preferential wettability of the particles, capillarity, and viscous forces encountered during mixing. Therefore all such systems share certain universal features, regardless of the details of the particles or fluids used. These features guide the construction of a non-equilibrium state diagram which takes the form of a triangular prism, where each triangular cross-section of the prism corresponds to a different relative affinity of the particles towards the two fluids. We classify the prism into regions in which the various morphologies appear and also emphasize the major difference between systems in which the particles are fully-wetted by one of the fluids vs. partially-wetted by both fluids. We also discuss how the state diagram may change with mixing intensity or with interparticle attractions.

  19. On the Impact of Layout Quality to Understanding UML Diagrams: Diagram Type and Expertise

    DEFF Research Database (Denmark)

    Störrle, Harald

    2012-01-01

    Practical experience suggests that the use and understanding of UML diagrams is greatly affected by the quality of their layout. In previous work, we have presented evidence supporting this intuition. This contrasts with earlier experiments that yielded weak or inconclusive evidence only. In the ...

  20. The Diagram as Story: Unfolding the Event-Structure of the Mathematical Diagram

    Science.gov (United States)

    de Freitas, Elizabeth

    2012-01-01

    This paper explores the role of narrative in decoding diagrams. I focus on two fundamental facets of narrative: (1) the recounting of causally related sequences of events, and (2) the positioning of the narrator through point-of-view and voice. In the first two sections of the paper I discuss philosophical and semiotic frameworks for making sense…

  1. Analysis of the phase solubility diagram of a phenacetin/competitor/beta-cyclodextrin ternary system, involving competitive inclusion complexation.

    Science.gov (United States)

    Ono, N; Hirayama, F; Arima, H; Uekama, K

    2001-01-01

    The competitive inclusion complexations in the ternary phenacetin/competitors/beta-cyclodextrin (beta-CyD) systems were investigated by the solubility method, where m-bromobenzoic acid (m-BBA) and o-toluic acid (o-TA) were used as competitors. The solubility changes of the drug and competitors as a function of beta-CyD concentration in the ternary systems were formulated using their stability constants and intrinsic solubilities. The decrease in solubility of phenacetin by the addition of competitors could be quantitatively simulated by the formulation, when both drug and competitor give A(L) type solubility diagrams. On the other hand, when one of the guests gives a B(S) type solubility diagram, its solubility change was clearly reflected in that of the another guest, i.e., phenacetin gave an A(L) type solubility diagram in the binary phenacetin/beta-CyD system and o-TA gave a B(S) type diagram in the binary o-TA/beta-CyD system, but in the ternary phenacetin/o-TA/beta-CyD system, a new plateau region appeared in the original A(L) type diagram of phenacetin. This was explained by the solubilization theory of Higuchi and Connors. The solubility analysis of the ternary drug/competitor/CyD systems may be particularly useful for determination of the stability constant of a drug whose physicochemical and spectroscopic analyses are difficult, because they can be calculated by monitoring the solubility change of a competitor, without monitoring that of a drug. Furthermore, the present results suggest that attention should be paid to the type of the phase solubility diagram, as well as the magnitude of the stability constant and the solubility of the complex, for a rational formulation design of CyD complexes.

  2. A Simplified Stabilizer ZX-calculus

    Directory of Open Access Journals (Sweden)

    Miriam Backens

    2017-01-01

    Full Text Available The stabilizer ZX-calculus is a rigorous graphical language for reasoning about quantum mechanics.The language is sound and complete: a stabilizer ZX-diagram can be transformed into another one if and only if these two diagrams represent the same quantum evolution or quantum state. We show that the stabilizer ZX-calculus can be simplified, removing unnecessary equations while keeping only the essential axioms which potentially capture fundamental structures of quantum mechanics. We thus give a significantly smaller set of axioms and prove that meta-rules like 'colour symmetry' and 'upside-down symmetry', which were considered as axioms in previous versions of the language, can in fact be derived. In particular, we show that the additional symbol and one of the rules which had been recently introduced to keep track of scalars (diagrams with no inputs or outputs are not necessary.

  3. Using Eye Tracking to Investigate Semantic and Spatial Representations of Scientific Diagrams During Text-Diagram Integration

    Science.gov (United States)

    Jian, Yu-Cin; Wu, Chao-Jung

    2015-02-01

    We investigated strategies used by readers when reading a science article with a diagram and assessed whether semantic and spatial representations were constructed while reading the diagram. Seventy-one undergraduate participants read a scientific article while tracking their eye movements and then completed a reading comprehension test. Our results showed that the text-diagram referencing strategy was commonly used. However, some readers adopted other reading strategies, such as reading the diagram or text first. We found all readers who had referred to the diagram spent roughly the same amount of time reading and performed equally well. However, some participants who ignored the diagram performed more poorly on questions that tested understanding of basic facts. This result indicates that dual coding theory may be a possible theory to explain the phenomenon. Eye movement patterns indicated that at least some readers had extracted semantic information of the scientific terms when first looking at the diagram. Readers who read the scientific terms on the diagram first tended to spend less time looking at the same terms in the text, which they read after. Besides, presented clear diagrams can help readers process both semantic and spatial information, thereby facilitating an overall understanding of the article. In addition, although text-first and diagram-first readers spent similar total reading time on the text and diagram parts of the article, respectively, text-first readers had significantly less number of saccades of text and diagram than diagram-first readers. This result might be explained as text-directed reading.

  4. Database design using entity-relationship diagrams

    CERN Document Server

    Bagui, Sikha

    2011-01-01

    Data, Databases, and the Software Engineering ProcessDataBuilding a DatabaseWhat is the Software Engineering Process?Entity Relationship Diagrams and the Software Engineering Life Cycle          Phase 1: Get the Requirements for the Database          Phase 2: Specify the Database          Phase 3: Design the DatabaseData and Data ModelsFiles, Records, and Data ItemsMoving from 3 × 5 Cards to ComputersDatabase Models     The Hierarchical ModelThe Network ModelThe Relational ModelThe Relational Model and Functional DependenciesFundamental Relational DatabaseRelational Database and SetsFunctional

  5. Phase diagram of a Schelling segregation model

    Science.gov (United States)

    Gauvin, L.; Vannimenus, J.; Nadal, J.-P.

    2009-07-01

    The collective behavior in a variant of Schelling’s segregation model is characterized with methods borrowed from statistical physics, in a context where their relevance was not conspicuous. A measure of segregation based on cluster geometry is defined and several quantities analogous to those used to describe physical lattice models at equilibrium are introduced. This physical approach allows to distinguish quantitatively several regimes and to characterize the transitions between them, leading to the building of a phase diagram. Some of the transitions evoke empirical sudden ethnic turnovers. We also establish links with ‘spin-1’ models in physics. Our approach provides generic tools to analyze the dynamics of other socio-economic systems.

  6. Phase Diagram of the Frustrated Hubbard Model

    Science.gov (United States)

    Zitzler, R.; Tong, N.-H.; Pruschke, Th.; Bulla, R.

    2004-07-01

    The Mott-Hubbard metal-insulator transition in the paramagnetic phase of the one-band Hubbard model has long been used to describe similar features in real materials like V2O3. In this Letter we investigate the antiferromagnetic phase of this model with frustration. At T=0 we find a first-order transition from a paramagnetic metal to an antiferromagnetic insulator. We show that even in the presence of strong magnetic frustration, the paramagnetic metal-insulator transition is hidden inside an extended antiferromagnetic region. This raises the question of whether the one-band Hubbard model with frustration is sufficient to describe the phase diagram of V2O3 or similar transition metal oxides even qualitatively.

  7. QCD phase diagram with isospin chemical potential

    CERN Document Server

    Brandt, Bastian B

    2016-01-01

    In this contribution we investigate the phase diagram of QCD in the presence of an isospin chemical potential. To alleviate the infrared problems of the theory associated with pion condensation, we introduce the pionic source as an infrared regulator. We discuss various methods to extrapolate the results to vanishing pionic source, including a novel method based on the singular value spectrum of the massive Dirac operator, a leading-order reweighting and a spline Monte-Carlo fit. Our main results concern the phase transition boundary between the normal and the pion condensation phases and the chiral/deconfinement transition temperature as a function of the chemical potential. In addition, we perform a quantitative comparison between our direct results and a Taylor-expansion obtained at zero chemical potential to assess the applicability range of the latter.

  8. Revised state diagram of Laponite dispersions.

    Science.gov (United States)

    Mongondry, Philippe; Tassin, Jean François; Nicolai, Taco

    2005-03-15

    We propose a state diagram of charged disk-like mineral particle (Laponite) dispersions as a function of the Laponite concentration (C) and the concentration of added salt (C(s)), based on simple observation and light-scattering measurements. At low C or high C(s) the dispersions separate into two domains due to sedimentation of Laponite aggregates, while at high C and low C(s) they form homogeneous gels that do not flow upon tube reversal. The aggregation rate and the structure factor of the Laponite dispersions is determined with light scattering as a function of C and C(s). We discuss in detail the controversy on the origin of gelation of Laponite dispersions in the absence of added salt. We argue that aggregation rather than glass formation causes gelation.

  9. Cuts and coproducts of massive triangle diagrams

    Energy Technology Data Exchange (ETDEWEB)

    Abreu, Samuel [Higgs Centre for Theoretical Physics, School of Physics and Astronomy,The University of Edinburgh,Mayfield Road, Edinburgh EH9 3JZ, Scotland (United Kingdom); Institut de Physique Théorique, Université Paris Saclay, CEA, CNRS,Orme des Merisiers, F-91191 Gif-sur-Yvette (France); Britto, Ruth [Institut de Physique Théorique, Université Paris Saclay, CEA, CNRS,Orme des Merisiers, F-91191 Gif-sur-Yvette (France); School of Mathematics, Trinity College,College Green, Dublin 2 (Ireland); Hamilton Mathematical Institute, Trinity College,College Green, Dublin 2 (Ireland); Grönqvist, Hanna [Institut de Physique Théorique, Université Paris Saclay, CEA, CNRS,Orme des Merisiers, F-91191 Gif-sur-Yvette (France)

    2015-07-21

    Relations between multiple unitarity cuts and coproducts of Feynman integrals are extended to allow for internal masses. These masses introduce new branch cuts, whose discontinuities can be derived by placing single propagators on shell and identified as particular entries of the coproduct. First entries of the coproduct are then seen to include mass invariants alone, as well as threshold corrections for external momentum channels. As in the massless case, the original integral can possibly be recovered from its cuts by starting with the known part of the coproduct and imposing integrability contraints. We formulate precise rules for cuts of diagrams, and we gather evidence for the relations to coproducts through a detailed study of one-loop triangle integrals with various combinations of external and internal masses.

  10. The Gamma Ray Bursts Hubble diagram

    CERN Document Server

    Capozziello, S; Dainotti, M G; De Laurentis, M; Izzo, L; Perillo, M

    2011-01-01

    Thanks to their enormous energy release, Gamma Rays Bursts (GRBs) have recently attracted a lot of interest to probe the Hubble diagram (HD) deep into the matter dominated era and hence complement Type Ia Supernovae (SNeIa). We consider here three different calibration methods based on the use of a fiducial LCDM model, on cosmographic parameters and on the local regression on SNeIa to calibrate the scaling relations proposed as an equivalent to the Phillips law to standardize GRBs finding any significant dependence. We then investigate the evolution of these parameters with the redshift to obtain any statistical improvement. Under this assumption, we then consider possible systematics effects on the HDs introduced by the calibration method, the averaging procedure and the homogeneity of the sample arguing against any significant bias.

  11. Specification of Learning Content Using Feature Diagrams

    Science.gov (United States)

    Damaševičius, Robertas

    The main idea of a learning object (LO) is to break educational content down into small chunks that can be reused in various learning environments. When reused, such small chunks of educational content are combined in various ways leading to a great variability of the learning content. We propose using feature diagrams (FDs) for the specification of learning content at different layers of abstraction starting from the organization of teaching material in a lecture down to the specification and demonstration of particular software/hardware components. FDs can be used by (1) designers, teachers, and learners for graphical representation of domain knowledge in LOs; (2) programmers to specify and express variability-commonality relationships of LOs at a higher abstraction level to allow the development and implementation of generative LOs; and (3) researchers as a vehicle for analysis and better understanding of the e-Learning domain itself.

  12. Bianchi I meets the Hubble diagram

    CERN Document Server

    Schucker, Thomas; Valent, Galliano

    2014-01-01

    We improve existing fits of the Bianchi I metric to the Hubble diagram of supernovae and find an intriguing yet non-significant signal for anisotropy that should be verified or falsified in the near future by the Large Synoptic Survey Telescope. Since the literature contains two different formulas for the apparent luminosity as a function of time of flight in Bianchi I metrics, we present an independent derivation confirming the result by Saunders (1969). The present fit differs from earlier ones by Koivisto & Mota and by Campanelli et al. in that we use Saunders' formula, a larger sample of supernovae, Union 2 and JLA, and we use the general Bianchi I metric with three distinct eigenvalues.

  13. Bayesian Image Reconstruction Based on Voronoi Diagrams

    CERN Document Server

    Cabrera, G F; Hitschfeld, N

    2007-01-01

    We present a Bayesian Voronoi image reconstruction technique (VIR) for interferometric data. Bayesian analysis applied to the inverse problem allows us to derive the a-posteriori probability of a novel parameterization of interferometric images. We use a variable Voronoi diagram as our model in place of the usual fixed pixel grid. A quantization of the intensity field allows us to calculate the likelihood function and a-priori probabilities. The Voronoi image is optimized including the number of polygons as free parameters. We apply our algorithm to deconvolve simulated interferometric data. Residuals, restored images and chi^2 values are used to compare our reconstructions with fixed grid models. VIR has the advantage of modeling the image with few parameters, obtaining a better image from a Bayesian point of view.

  14. Understanding starch gelatinization: The phase diagram approach.

    Science.gov (United States)

    Carlstedt, Jonas; Wojtasz, Joanna; Fyhr, Peter; Kocherbitov, Vitaly

    2015-09-20

    By constructing a detailed phase diagram for the potato starch-water system based on data from optical microscopy, synchrotron X-ray scattering and differential scanning calorimetry, we show that gelatinization can be interpreted in analogy with a eutectic transition. The phase rule explains why the temperature of the gelatinization transition (G) is independent on water content. Furthermore, the melting (M1) endotherm observed in DSC represents a liquidus line; the temperature for this event increases with increasing starch concentration. Both the lamellar spacing and the inter-helix distance were observed to decrease with increasing starch content for starch concentrations between approximately 65 wt% and 75 wt%, while the inter-helix distance continued decreasing upon further dehydration. Understanding starch gelatinization has been a longstanding challenge. The novel approach presented here shows interpretation of this phenomenon from a phase equilibria perspective. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Improving perturbation theory with cactus diagrams

    CERN Document Server

    Constantinou, M; Skouroupathis, A; Constantinou, Martha; Panagopoulos, Haralambos; Skouroupathis, Apostolos

    2006-01-01

    We study a systematic improvement of perturbation theory for gauge fields on the lattice [hep-lat/0606001]; the improvement entails resumming, to all orders in the coupling constant, a dominant subclass of tadpole diagrams. This method, originally proposed for the Wilson gluon action, is extended here to encompass all possible gluon actions made of closed Wilson loops; any fermion action can be employed as well. The effect of resummation is to replace various parameters in the action (coupling constant, Symanzik and clover coefficient) by ``dressed'' values; the latter are solutions to certain coupled integral equations, which are easy to solve numerically. Some positive features of this method are: a) It is gauge invariant, b) it can be systematically applied to improve (to all orders) results obtained at any given order in perturbation theory, c) it does indeed absorb in the dressed parameters the bulk of tadpole contributions. Two different applications are presented: The additive renormalization of fermio...

  16. The Phase Diagram of Superionic Ice

    Science.gov (United States)

    Sun, Jiming; Clark, Bryan; Car, Roberto

    2014-03-01

    Using the variable cell Car-Parrinello molecular dynamics method, we study the phase diagram of superionic ice from 200GPa to 2.5TPa. We present evidence that at very high pressure the FCC structure of the oxygen sublattice may become unstable allowing for a new superionic ice phase, in which the oxygen sublattice takes the P21 structure found in zero-temperature total energy calculations. We also report on how the melting temperature of the hydrogen sublattice is affected by this new crystalline structure of the oxygen sublattice. This work was supported by the NSF under grant DMS-1065894(J.S. and R.C.) and PHY11-25915(B.C.).

  17. The Eh-pH Diagram and Its Advances

    OpenAIRE

    Hsin-Hsiung Huang

    2016-01-01

    Since Pourbaix presented Eh versus pH diagrams in his “Atlas of Electrochemical Equilibria in Aqueous Solution”, diagrams have become extremely popular and are now used in almost every scientific area related to aqueous chemistry. Due to advances in personal computers, such diagrams can now show effects not only of Eh and pH, but also of variables, including ligand(s), temperature and pressure. Examples from various fields are illustrated in this paper. Examples include geochemical formation,...

  18. Duals of Orphan-Free Anisotropic Voronoi Diagrams are Triangulations

    CERN Document Server

    Canas, Guillermo D

    2011-01-01

    We show that, under mild conditions on the underlying metric, duals of appropriately defined anisotropic Voronoi diagrams are embedded triangulations. Furthermore, they always triangulate the convex hull of the vertices, and have other properties that parallel those of ordinary Delaunay triangulations. These results apply to the duals of anisotropic Voronoi diagrams of any set of vertices, so long as the diagram is orphan-free.

  19. Zone diagrams in compact subsets of uniformly convex normed spaces

    OpenAIRE

    Kopecká, E. (Eva); Reem, D.; Reich, S.

    2012-01-01

    A zone diagram is a relatively new concept which has emerged in computational geometry and is related to Voronoi diagrams. Formally, it is a fixed point of a certain mapping, and neither its uniqueness nor its existence are obvious in advance. It has been studied by several authors, starting with T. Asano, J. Matousek and T. Tokuyama, who considered the Euclidean plane with singleton sites, and proved the existence and uniqueness of zone diagrams there. In the present paper we prove the exist...

  20. Zone diagrams in compact subsets of uniformly convex normed spaces

    OpenAIRE

    2010-01-01

    A zone diagram is a relatively new concept which has emerged in computational geometry and is related to Voronoi diagrams. Formally, it is a fixed point of a certain mapping, and neither its uniqueness nor its existence are obvious in advance. It has been studied by several authors, starting with T. Asano, J. Matousek and T. Tokuyama, who considered the Euclidean plane with singleton sites, and proved the existence and uniqueness of zone diagrams there. In the present paper we prove the exist...

  1. Thermodynamic Equilibrium Diagrams of Sulphur-Chromium System

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The chemical and electrochemical equilibria in the presence of gaseous phase were investigated. Many substances, which consisted of sulphur and chromium, were considered. Various thermodynamic equilibria were calculated in different pressures. Calculation results were shown as log p―1/T and E―T diagrams. These diagrams may be used to study the corrosion of chromium in sulphur-containing circumstances. The diagrams are also used to thermodynami-cally determine the existence area of various substances and so on.

  2. Solid-liquid phase diagram of disubstituted benzene systems

    Institute of Scientific and Technical Information of China (English)

    黑恩成; 刘国杰

    1995-01-01

    The cooling curves of different compositions of the systems of ortho-chlorotoluene/para-chlorotoluene and ortho-nitrochlorobenzene/para-nitrochlorobenzene are carefully determined by the thermal analysis method. The crystals obtained are also tested. The conclusion that both systems are of simple eutectic diagram but not the solid solution diagram with a minimum melting point is confirmed. The characteristics of the diagram are explained according to the physical and thermodynarmc properties of the components.

  3. Phase Diagrams for Systems Containing Hyperbranched Polymers

    Directory of Open Access Journals (Sweden)

    Tim Zeiner

    2012-01-01

    Full Text Available Hyperbranched polymers show an outstanding potential for applications ranging from chemistry over nanotechnology to pharmacy. In order to take advantage of this potential, the underlying phase behaviour must be known. From the thermodynamic point of view, the modelling of these phase diagrams is quite challenging, because the thermodynamic properties depend on the architecture of the hyperbranched polymer as well as on the number and kind of present functional end groups. The influence of architecture can be taken into account via the lattice cluster theory (LCT as an extension of the well-known Flory–Huggins theory. Whereas the Flory–Huggins theory is limited to linear polymer chains, the LCT can be applied to an arbitrary chain architecture. The number and the kind of functional groups can be handled via the Wertheim perturbation theory, applicable for directed forces between the functional groups and the surrounding solvent molecules. The combination of the LCT and the Wertheim theory can be established for the modelling or even prediction of the liquid-liquid equilibria (LLE of polymer solutions in a single solvent or in a solvent mixture or polymer blends, where the polymer can have an arbitrary structure. The applied theory predicts large demixing regions for mixtures of linear polymers and hyperbranched polymers, as well as for mixtures made from two hyperbranched polymers. The introduction of empty lattice sites permits the theoretical investigation of pressure effects on phase behaviour. The calculated phase diagrams were compared with own experimental data or to experimental data taken from literature.

  4. The Margins of Medieval Manuscripts

    Directory of Open Access Journals (Sweden)

    Nataša Kavčič

    2011-12-01

    Full Text Available Shortly after the mid-thirteenth century, various images began to fill the margins in both religious and secular texts. Many factors influenced the emergence of this type of manuscript decoration, but it has generally been attributed to the revived interest in nature and the Gothic inclination for humorous and anecdotic detail. After highlighting other possible reasons for the occurrence of marginal illumination, this paper introduces two manuscripts from the Archiepiscopal Archives in Ljubljana. The manuscripts show numerous facial drawings affixed to some of the letters. This article addresses how to interpret such drawings and stresses that they do not necessarily function as symbolic images or images with any specific didactic value. Quite the opposite, these drawings seem not to have any meaning and are oft en merely indications of an illuminator’s sense of humor. Because of their exaggerated facial expressions, these drawings could be perceived as the true predecessors of modern caricature.

  5. Respiration in ocean margin sediments

    OpenAIRE

    Andersson, J.H.

    2007-01-01

    The aim of this thesis was the study of respiration in ocean margin sediments and the assessments of tools needed for this purpose. The first study was on the biological pump and global respiration patterns in the deep ocean using an empirical model based on sediment oxygen consumption data. In this thesis the depth dependence of respiration patterns was modelled using a compiled data set of sediment oxygen consumption rates. We showed that the depth relationship can best be described by a do...

  6. Computer recognition of slag property diagrams in ternary systems

    Institute of Scientific and Technical Information of China (English)

    Jinxiong Lu; Li Wang; Jiongming Zhang; Xinhua Wang

    2004-01-01

    In order to take data information from the slag property diagram in a ternary system automatically and actually, a picture recognition and drawing software has been developed by Visual Basic 6.0 based on the image coding principle of computer system and the graphics programming method of VB. This software can transform the ternary system isopleth diagram from bitmap format to data file and establish a corresponding database which can be applied to rapidly retrieve a mass of data and make correlative thermodynamics or kinetics calculation. Besides, it still has the function of drawing the ternary system diagram which can draw different kinds of property parameters in the same diagram.

  7. Wellformedness properties in Euler diagrams: which should be used?

    Science.gov (United States)

    Rodgers, Peter; Zhang, Leishi; Purchase, Helen

    2012-07-01

    Euler diagrams are often used to visualize intersecting data sets in applications such as criminology; genetics, medicine, and computer file systems. One interesting aspect of these diagrams is that some data sets cannot be drawn without breaking one or more "wellformedness properties," which are considered to reduce the user comprehension of the diagrams. However, it is possible to draw the same data with different diagrams, each of which breaks different wellformedness properties. Hence, some properties are "swappable," so motivating the study of which of the alternatives would be best to use. This paper reports on the two empirical studies to determine how wellformedness properties affect comprehension. One study was with abstract data, the other was with concrete data that visualized students' enrollment on university modules. We have results from both studies that imply that diagrams with concurrency or disconnected zones perform less well than other some other properties. Further, we have no results that imply that diagrams with brushing points adversely affect performance. Our data also indicate that nonsimple curves are preferred less than diagrams with other properties. These results will inform both human diagram designers and the developers of automated drawing systems on the best way to visualize data using Euler diagrams.

  8. Visualization design and verification of Ada tasking using timing diagrams

    Science.gov (United States)

    Vidale, R. F.; Szulewski, P. A.; Weiss, J. B.

    1986-01-01

    The use of timing diagrams is recommended in the design and testing of multi-task Ada programs. By displaying the task states vs. time, timing diagrams can portray the simultaneous threads of data flow and control which characterize tasking programs. This description of the system's dynamic behavior from conception to testing is a necessary adjunct to other graphical techniques, such as structure charts, which essentially give a static view of the system. A series of steps is recommended which incorporates timing diagrams into the design process. Finally, a description is provided of a prototype Ada Execution Analyzer (AEA) which automates the production of timing diagrams from VAX/Ada debugger output.

  9. Global phase diagram of a doped Kitaev-Heisenberg model

    Energy Technology Data Exchange (ETDEWEB)

    Okamoto, Satoshi [ORNL

    2013-01-01

    The global phase diagram of a doped Kitaev-Heisenberg model is studied using an $SU(2)$ slave-boson mean-field method. Near the Kitaev limit, $p$-wave superconducting states which break the time-reversal symmetry are stabilized as reported by You {\\it et al.} [Phys. Rev. B {\\bf 86}, 085145 (2012)] irrespective of the sign of the Kitaev interaction. By further doping, a $d$-wave superconducting state appears when the Kitaev interaction is antiferromagnetic, while another $p$-wave superconducting state appears when the Kitaev interaction is ferromagnetic. This $p$-wave superconducting state does not break the time-reversal symmetry as reported by Hyart {\\it et al.} [Phys. Rev. B {\\bf 85}, 140510 (2012)], and such a superconducting state also appears when the antiferromagnetic Kitaev interaction and the ferromagnetic Heisenberg interaction compete. This work, thus, demonstrates the clear difference between the antiferromagnetic Kitaev model and the ferromagnetic Kitaev model when carriers are doped while these models are equivalent in the undoped limit, and how novel superconducting states emerge when the Kitaev interaction and the Heisenberg interaction compete.

  10. Reliability block diagrams to model the management of colorectal cancer.

    Science.gov (United States)

    Sonnenberg, A; Inadomi, J M

    1999-02-01

    The present study aims to show how various medical and nonmedical components contribute to success and failure in the management of colorectal cancer. The first encounter, subsequent diagnosis, and surgical therapy of a patient with Dukes B sigmoid cancer is modeled as a reliability block diagram with a serial and parallel arrangement of various components. The overall probability of a patient with new-onset colorectal cancer to visit a physician, be correctly diagnosed, and undergo successful therapy is 69%. The reduction in the overall success, despite the fact that the majority of components are assumed to function with failure rates of 5% or less, is a reflection of the multitude of serial subsystems involved in the management of the patient. In contrast, the parallel arrangement of subsystems results in a relative insensitivity of the overall system to failure, a greater stability, and an improved performance. Since no medical system functions perfectly, redundancy associated with parallel subsystems assures a better overall outcome. System analysis of health care provides a means to improve its performance.

  11. Condensation phase diagrams for lipid-coated perfluorobutane microbubbles.

    Science.gov (United States)

    Mountford, Paul A; Sirsi, Shashank R; Borden, Mark A

    2014-06-03

    The goal of this study was to explore the thermodynamic conditions necessary to condense aqueous suspensions of lipid-coated gas-filled microbubbles into metastable liquid-filled nanodrops as well as the physicochemical mechanisms involved with this process. Individual perfluorobutane microbubbles and their lipid shells were observed as they were pressurized at 34.5 kPa s(-1) in a microscopic viewing chamber maintained at temperatures ranging from 5 to 75 °C. The microbubbles contracted under pressure, ultimately leading to either full dissolution or microbubble-to-nanodrop condensation. Temperature-pressure phase diagrams conveying condensation and stability transitions were constructed for microbubbles coated with saturated diacylphosphatidylcholine lipids of varying acyl chain length (C16 to C24). The onset of full dissolution was shifted to higher temperatures with the use of longer acyl chain lipids or supersaturated media. Longer chain lipid shells resisted both dissolution of the gas core and mechanical compression through a pronounced wrinkle-to-fold collapse transition. Interestingly, the lipid shell also provided a mechanical resistance to condensation, shifting the vapor-to-liquid transition to higher pressures than for bulk perfluorobutane. This result indicated that the lipid shell can provide a negative apparent surface tension under compression. Overall, the results of this study will aid in the design and formulation of vaporizable fluorocarbon nanodrops for various applications, such as diagnostic ultrasound imaging, targeted drug delivery, and thermal ablation.

  12. Looking for chemical reaction networks exhibiting a drift along a manifold of marginally stable states.

    Science.gov (United States)

    Brogioli, Doriano

    2013-02-07

    I recently reported some examples of mass-action equations that have a continuous manifold of marginally stable stationary states [Brogioli, D., 2010. Marginally stable chemical systems as precursors of life. Phys. Rev. Lett. 105, 058102; Brogioli, D., 2011. Marginal stability in chemical systems and its relevance in the origin of life. Phys. Rev. E 84, 031931]. The corresponding chemical reaction networks show nonclassical effects, i.e. a violation of the mass-action equations, under the effect of the concentration fluctuations: the chemical system drifts along the marginally stable states. I proposed that this effect is potentially involved in abiogenesis. In the present paper, I analyze the mathematical properties of mass-action equations of marginally stable chemical reaction networks. The marginal stability implies that the mass-action equations obey some conservation law; I show that the mathematical properties of the conserved quantity characterize the motion along the marginally stable stationary state manifold, i.e. they allow to predict if the fluctuations give rise to a random walk or a drift under the effect of concentration fluctuations. Moreover, I show that the presence of the drift along the manifold of marginally stable stationary-states is a critical property, i.e. at least one of the reaction constants must be fine tuned in order to obtain the drift.

  13. Thermodynamic study of CVD-ZrO{sub 2} phase diagrams

    Energy Technology Data Exchange (ETDEWEB)

    Torres-Huerta, A.M., E-mail: atorresh@ipn.m [Research Center for Applied Science and Advanced Technology, Altamira-IPN, Altamira C.P.89600 Tamaulipas (Mexico); Vargas-Garcia, J.R. [Dept of Metallurgical Eng., ESIQIE-IPN, Mexico 07300 D.F. (Mexico); Dominguez-Crespo, M.A. [Research Center for Applied Science and Advanced Technology, Altamira-IPN, Altamira C.P.89600 Tamaulipas (Mexico); Romero-Serrano, J.A. [Dept of Metallurgical Eng., ESIQIE-IPN, Mexico 07300 D.F. (Mexico)

    2009-08-26

    Chemical vapor deposition (CVD) of zirconium oxide (ZrO{sub 2}) from zirconium acetylacetonate Zr(acac){sub 4} has been thermodynamically investigated using the Gibbs' free energy minimization method and the FACTSAGE program. Thermodynamic data Cp{sup o}, DELTAH{sup o} and S{sup o} for Zr(acac){sub 4} have been estimated using the Meghreblian-Crawford-Parr and Benson methods because they are not available in the literature. The effect of deposition parameters, such as temperature and pressure, on the extension of the region where pure ZrO{sub 2} can be deposited was analyzed. The results are presented as calculated CVD stability diagrams. The phase diagrams showed two zones, one of them corresponds to pure monoclinic phase of ZrO{sub 2} and the other one corresponds to a mix of monoclinic phase of ZrO{sub 2} and graphite carbon.

  14. Temperature-pressure phase diagram of cubic Laves phase Au2Pb

    Science.gov (United States)

    Chen, K. W.; Graf, D.; Besara, T.; Gallagher, A.; Kikugawa, N.; Balicas, L.; Siegrist, T.; Shekhter, A.; Baumbach, R. E.

    2016-01-01

    The temperature (T ) as a function of pressure (P ) phase diagram is reported for the cubic Laves phase compound Au2Pb, which was recently proposed to support linearly dispersing topological bands, together with conventional quadratic bands. At ambient pressure, Au2Pb exhibits several structural phase transitions at T1=97 K , T2=51 K , and T3=40 K with superconductivity below Tc=1.2 K . Applied pressure results in a rich phase diagram where T1,T2, and T3 evolve strongly with P and a possible new phase is stabilized for P >0.64 GPa that also supports superconductivity below 1.1 K. These observations suggest that Au2Pb is an ideal system in which to investigate the relationship between structural degrees of freedom, band topology, and resulting anomalous behaviors.

  15. To use or no to use diagrams: The effect of drawing a diagram in solving introductory physics problems

    CERN Document Server

    Maries, Alexandru

    2016-01-01

    Drawing appropriate diagrams is a useful problem solving heuristic that can transform a give problem into a representation that is easier to exploit for solving it. A major focus while helping introductory physics students learn problem solving is to help them appreciate that drawing a diagram facilitates problem solution. We conducted an investigation in which 111 students in an algebra-based introductory physics course were subjected to two different interventions during recitation quizzes throughout the semester. They were either (1) asked to solve problems in which the diagrams were drawn for them or (2) explicitly told to draw a diagram. A comparison group was not given any instruction regarding diagrams. We developed a rubric to score the problem-solving performance of students in different intervention groups. We investigated two problems involving electric field and electric force and found that students who draw expert-like diagrams are more successful problem solvers and that a higher level of detai...

  16. Oak Ridge K-25 Site Technology Logic Diagram. Volume 2, Technology Logic Diagrams

    Energy Technology Data Exchange (ETDEWEB)

    Fellows, R.L. [ed.

    1993-02-26

    The Oak Ridge K-25 Technology Logic Diagram (TLD), a decision support tool for the K-25 Site, was developed to provide a planning document that relates envirorunental restoration and waste management problems at the Oak Ridge K-25 Site to potential technologies that can remediate these problems. The TLD technique identifies the research necessary to develop these technologies to a state that allows for technology transfer and application to waste management, remedial action, and decontamination and decommissioning activities. The TLD consists of four separate volumes-Vol. 1, Vol. 2, Vol. 3A, and Vol. 3B. Volume 1 provides introductory and overview information about the TLD. This volume, Volume 2, contains logic diagrams with an index. Volume 3 has been divided into two separate volumes to facilitate handling and use.

  17. OntoDiagram: Automatic Diagram Generation for Congenital Heart Defects in Pediatric Cardiology

    OpenAIRE

    Vishwanath, Kartik; Viswanath, Venkatesh; Drake, William; Lee, Yugyung

    2005-01-01

    In pediatric cardiology as well as many other medical specialties, the accurate portrayal of a large volume of patient information is crucial to providing good patient care. Our research aims at utilizing clinical and spatial ontologies representing the human heart, to automatically generate a Mullins-like diagram [6] based on a patient's information in the cardiology databases. Our ontology allows an intuitive way of modeling congenital defects with the structure of the hum...

  18. THE SYSTEM NEODYMIUM - MANGANESE (STRUCTURES, MAGNETIC PROPERTIES, PHASE DIAGRAM), THE PHASE DIAGRAMS YB-HG AND TB-HG,

    Science.gov (United States)

    ALLOYS, YTTERBIUM, TERBIUM, MANGANESE ALLOYS, MERCURY ALLOYS, X RAY DIFFRACTION, X RAY SPECTROSCOPY, DIFFERENTIAL THERMAL ANALYSIS, PHASE DIAGRAMS , MAGNETIC PROPERTIES, CRYSTAL STRUCTURE, METALLOGRAPHY, AUSTRIA

  19. Enantiomeric 3-chloromandelic acid system: binary melting point phase diagram, ternary solubility phase diagrams and polymorphism.

    Science.gov (United States)

    Le Minh, Tam; von Langermann, Jan; Lorenz, Heike; Seidel-Morgenstern, Andreas

    2010-09-01

    A systematic study of binary melting point and ternary solubility phase diagrams of the enantiomeric 3-chloromandelic acid (3-ClMA) system was performed under consideration of polymorphism. The melting point phase diagram was measured by means of thermal analysis, that is, using heat-flux differential scanning calorimetry (DSC). The results reveal that 3-ClMA belongs to the racemic compound-forming systems. Polymorphism was found for both the enantiomer and the racemate as confirmed by X-ray powder diffraction analysis. The ternary solubility phase diagram of 3-ClMA in water was determined between 5 and 50 degrees C by the classical isothermal technique. The solubilities of the pure enantiomers are extremely temperature-dependent. The solid-liquid equilibria of racemic 3-ClMA are not trivial due to the existence of polymorphism. The eutectic composition in the chiral system changes as a function of temperature. Further, solubility data in the alternative solvent toluene are also presented.

  20. Estimation of isothermal sections of ternary phase diagrams of lithium containing systems: the Al--Li--Mg system

    Energy Technology Data Exchange (ETDEWEB)

    Saboungi, M. L.; Hsu, C. C.

    1976-12-01

    The method of Kaufman and coworkers is used to provide an estimate of isothermal sections of the Al--Li--Mg system. One starts by calculating the lattice stability of the constituents, the binary interaction coefficients and the binary compound parameters. In the computations, thermodynamic data, when available, were coupled with measured phase diagrams to provide thermodynamically self-consistent liquidus and solidus curves for the binary systems. Standard enthalpies of formation and entropies of formation were calculated for the reported compounds. The binary system Li--Mg illustrates the use of such calculations in selecting the most reliable representation of the phase diagram. The calculated binary data were used to compute the phase diagram of Li--Al--Mg, assuming that no ternary compounds exist. 4 tables, 7 figures, 29 references. (GHT)

  1. Margin Requirements and Equity Option Returns

    DEFF Research Database (Denmark)

    Hitzemann, Steffen; Hofmann, Michael; Uhrig-Homburg, Marliese

    In equity option markets, traders face margin requirements both for the options themselves and for hedging-related positions in the underlying stock market. We show that these requirements carry a significant margin premium in the cross-section of equity option returns. The sign of the margin pre...

  2. Exploring the QCD phase diagram through relativistic heavy ion collisions

    CERN Document Server

    Mohanty, Bedangadas

    2013-01-01

    We present a review of the studies related to establishing the QCD phase diagram through high energy nucleus-nucleus collisions. We particularly focus on the experimental results related to the formation of a quark-gluon phase, crossover transition and search for a critical point in the QCD phase diagram.

  3. Drawing Euler Diagrams with Circles: The Theory of Piercings.

    Science.gov (United States)

    Stapleton, Gem; Leishi Zhang; Howse, John; Rodgers, Peter

    2011-07-01

    Euler diagrams are effective tools for visualizing set intersections. They have a large number of application areas ranging from statistical data analysis to software engineering. However, the automated generation of Euler diagrams has never been easy: given an abstract description of a required Euler diagram, it is computationally expensive to generate the diagram. Moreover, the generated diagrams represent sets by polygons, sometimes with quite irregular shapes that make the diagrams less comprehensible. In this paper, we address these two issues by developing the theory of piercings, where we define single piercing curves and double piercing curves. We prove that if a diagram can be built inductively by successively adding piercing curves under certain constraints, then it can be drawn with circles, which are more esthetically pleasing than arbitrary polygons. The theory of piercings is developed at the abstract level. In addition, we present a Java implementation that, given an inductively pierced abstract description, generates an Euler diagram consisting only of circles within polynomial time.

  4. Heuristic Diagrams as a Tool to Teach History of Science

    Science.gov (United States)

    Chamizo, Jose A.

    2012-01-01

    The graphic organizer called here heuristic diagram as an improvement of Gowin's Vee heuristic is proposed as a tool to teach history of science. Heuristic diagrams have the purpose of helping students (or teachers, or researchers) to understand their own research considering that asks and problem-solving are central to scientific activity. The…

  5. RNA secondary structure diagrams for very large molecules: RNAfdl

    DEFF Research Database (Denmark)

    Hecker, Nikolai; Wiegels, Tim; Torda, Andrew E.

    2013-01-01

    There are many programs that can read the secondary structure of an RNA molecule and draw a diagram, but hardly any that can cope with 10 3 bases. RNAfdl is slow but capable of producing intersection-free diagrams for ribosome-sized structures, has a graphical user interface for adjustments...

  6. The Formal Semantics of an UML Activity Diagram

    Institute of Scientific and Technical Information of China (English)

    梁义芝; 王延章; 刘云飞

    2004-01-01

    Due to lack of strictly defined formal semantics, an UML activity diagram is unsuitable for the tasks of formal analysis, verification and assertion on the system it describes. In this paper, Petri net is used to define the formal semantics of an UML activity diagram containing object flow states, laying a foundation for the precise description and analysis of a workflow system.

  7. Heuristic Diagrams as a Tool to Teach History of Science

    Science.gov (United States)

    Chamizo, Jose A.

    2012-01-01

    The graphic organizer called here heuristic diagram as an improvement of Gowin's Vee heuristic is proposed as a tool to teach history of science. Heuristic diagrams have the purpose of helping students (or teachers, or researchers) to understand their own research considering that asks and problem-solving are central to scientific activity. The…

  8. 30 CFR 256.8 - Leasing maps and diagrams.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Leasing maps and diagrams. 256.8 Section 256.8 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE LEASING OF SULPHUR OR..., General § 256.8 Leasing maps and diagrams. (a) Any area of the OCS which has been appropriately platted...

  9. Do students use and understand free-body diagrams?

    Directory of Open Access Journals (Sweden)

    David Rosengrant

    2009-06-01

    Full Text Available Physics education literature recommends using multiple representations to help students understand concepts and solve problems. However, there is little research concerning why students use the representations and whether those who use them are more successful. This study addresses these questions using free-body diagrams (diagrammatic representations used in problems involving forces as a type of representation. We conducted a two-year quantitative and qualitative study of students’ use of free-body diagrams while solving physics problems. We found that when students are in a course that consistently emphasizes the use of free-body diagrams, the majority of them do use diagrams on their own to help solve exam problems even when they receive no credit for drawing the diagrams. We also found that students who draw diagrams correctly are significantly more successful in obtaining the right answer for the problem. Lastly, we interviewed students to uncover their reasons for using free-body diagrams. We found that high achieving students used the diagrams to help solve the problems and as a tool to evaluate their work while low achieving students only used representations as aids in the problem-solving process.

  10. An Introductory Idea for Teaching Two-Component Phase Diagrams

    Science.gov (United States)

    Peckham, Gavin D.; McNaught, Ian J.

    2011-01-01

    The teaching of two-component phase diagrams has attracted little attention in this "Journal," and it is hoped that this article will make a useful contribution. Current physical chemistry textbooks describe two-component phase diagrams adequately, but do so in a piecemeal fashion one section at a time; first solid-liquid equilibria, then…

  11. The Effect of Causal Diagrams on Text Learning

    Science.gov (United States)

    McCrudden, Matthew T.; Schraw, Gregory; Lehman, Stephen; Poliquin, Anne

    2007-01-01

    We examined the effect of studying a causal diagram on comprehension of causal relationships from an expository science text. A causal diagram is a type of visual display that explicitly represents cause-effect relationships. In Experiment 1, readers between conditions did not differ with respect to memory for main ideas, but the readers who…

  12. Alnus as a disturbing factor in pollen diagrams

    NARCIS (Netherlands)

    Janssen, C.R.

    1959-01-01

    It is commonly accepted that percentages of pollen in a pollen diagram do not express the exact composition of forests in earlier times. This inaccuracy is due to several factors, for instance the different quantities of pollen produced by plants, the distance of transport etc. A pollen diagram tell

  13. Using a Spreadsheet To Explore Melting, Dissolving and Phase Diagrams.

    Science.gov (United States)

    Goodwin, Alan

    2002-01-01

    Compares phase diagrams relating to the solubilities and melting points of various substances in textbooks with those generated by a spreadsheet using data from the literature. Argues that differences between the diagrams give rise to new chemical insights. (Author/MM)

  14. Phase Diagrams of Silicate Systems: Handbook; Third Issue; Ternary Systems

    Science.gov (United States)

    In the third issue of the handbook Phase Diagrams of Silicate Systems, information is included on the phase relationships in systems containing...radioelectronics, nuclear engineering, etc. Not only are equilibrium phase diagrams presented in the handbook, but the phases existing in the

  15. Water, Water Everywhere: Phase Diagrams of Ordinary Water Substance

    Science.gov (United States)

    Glasser, L.

    2004-01-01

    The full phase diagram of water in the form of a graphical representation of the three-dimensional (3D) PVT diagram using authentic data is presented. An interesting controversy regarding the phase behavior of water was the much-touted proposal of a solid phase of water, polywater, supposedly stable under atmospheric conditions.

  16. Pourbaix ("E"-pH-M) Diagrams in Three Dimensions

    Science.gov (United States)

    Pesterfield, Lester L.; Maddox, Jeremy B.; Crocker, Michael S.; Schweitzer, George K.

    2012-01-01

    "E"-pH (Pourbaix) diagrams provide an important graphical link between the thermodynamic calculations of potential, pH, equilibrium constant, concentration, and changes in Gibbs energy and the experimentally observed behavior of species in aqueous solutions. The utility of "E"-pH diagrams is extended with the introduction of an additional…

  17. Biomass energy and marginal areas

    Energy Technology Data Exchange (ETDEWEB)

    Chassany, J.P.

    1984-01-01

    The aim of this study was to analyze the conditions and effects of a possible development of the biomass energy upgrading in uneconomical or not rentable areas. The physical, social and economical characteristics of these regions (in France) are described; then the different types of biomass are presented (agricultural wastes, energetic cultures, forest and land products and residues, food processing effluents, municipal wastes) as well as the various energy process (production of alcohol, methane, thermochemical processes, vegetable oils). The development and the feasability of these processes in marginal areas are finally analyzed taking into account the accessibility of the biomass and the technical and commercial impacts.

  18. A comparison of two approaches for solving unconstrained influence diagrams

    DEFF Research Database (Denmark)

    Ahlmann-Ohlsen, Kristian S.; Jensen, Finn V.; Nielsen, Thomas Dyhre

    2009-01-01

    Influence diagrams and decision trees represent the two most common frameworks for specifying and solving decision problems. As modeling languages, both of these frameworks require that the decision analyst specifies all possible sequences of observations and decisions (in influence diagrams......, this requirement corresponds to the constraint that the decisions should be temporarily linearly ordered). Recently, the unconstrained influence diagram was proposed to address this drawback. In this framework, we may have a partial ordering of the decisions, and a solution to the decision problem therefore...... consists not only of a decision policy for the various decisions, but also of a conditional specification of what to do next. Relative to the complexity of solving an influence diagram, finding a solution to an unconstrained influence diagram may be computationally very demanding w.r.t. both time and space...

  19. Analysis of Sequence Diagram Layout in Advanced UML Modelling Tools

    Directory of Open Access Journals (Sweden)

    Ņikiforova Oksana

    2016-05-01

    Full Text Available System modelling using Unified Modelling Language (UML is the task that should be solved for software development. The more complex software becomes the higher requirements are stated to demonstrate the system to be developed, especially in its dynamic aspect, which in UML is offered by a sequence diagram. To solve this task, the main attention is devoted to the graphical presentation of the system, where diagram layout plays the central role in information perception. The UML sequence diagram due to its specific structure is selected for a deeper analysis on the elements’ layout. The authors research represents the abilities of modern UML modelling tools to offer automatic layout of the UML sequence diagram and analyse them according to criteria required for the diagram perception.

  20. Calculation of Gallium-metal-Arsenic phase diagrams

    Science.gov (United States)

    Scofield, J. D.; Davison, J. E.; Ray, A. E.; Smith, S. R.

    1991-01-01

    Electrical contacts and metallization to GaAs solar cells must survive at high temperatures for several minutes under specific mission scenarios. The determination of which metallizations or alloy systems that are able to withstand extreme thermal excursions with minimum degradation to solar cell performance can be predicted by properly calculated temperature constitution phase diagrams. A method for calculating a ternary diagram and its three constituent binary phase diagrams is briefly outlined and ternary phase diagrams for three Ga-As-X alloy systems are presented. Free energy functions of the liquid and solid phase are approximated by the regular solution theory. Phase diagrams calculated using this method are presented for the Ga-As-Ge and Ga-As-Ag systems.

  1. Efficient computation of clipped Voronoi diagram for mesh generation

    KAUST Repository

    Yan, Dongming

    2013-04-01

    The Voronoi diagram is a fundamental geometric structure widely used in various fields, especially in computer graphics and geometry computing. For a set of points in a compact domain (i.e. a bounded and closed 2D region or a 3D volume), some Voronoi cells of their Voronoi diagram are infinite or partially outside of the domain, but in practice only the parts of the cells inside the domain are needed, as when computing the centroidal Voronoi tessellation. Such a Voronoi diagram confined to a compact domain is called a clipped Voronoi diagram. We present an efficient algorithm to compute the clipped Voronoi diagram for a set of sites with respect to a compact 2D region or a 3D volume. We also apply the proposed method to optimal mesh generation based on the centroidal Voronoi tessellation. Crown Copyright © 2011 Published by Elsevier Ltd. All rights reserved.

  2. The dysprosium-tin phase diagram

    Energy Technology Data Exchange (ETDEWEB)

    Eremenko, V.N.; Bulanova, M.V.; Martsenjuk, P.S. (I.N. Frantsevich Inst. for Problems of Materials Science, Kiev (Ukraine))

    1992-12-07

    The dysprosium-tin phase diagram was established by means of differential thermal, X-ray and microscopic analyses of 22 alloys. Seven intermetallic compounds were found to exist in the system. Dy[sub 5]Sn[sub 3] melts congruently at 1870 degC, and undergoes a polymorphous transformation at 1823 [+-] 6 degC. The intermetallics Dy[sub 5]Sn[sub 4], Dy[sub 11]Sn[sub 10], DySn, Dy[sub 4]Sn[sub 5], DySn[sub 2], DySn[sub 3] are formed peritectically at 1712 [+-]11, 1605 [+-]12, 1208 [+-]3, 1166 [+-]7, 1138 [+-]3 and 747 [+-]6 degC respectively. DySn[sub 3] exists in a narrow temperature range, in two polymorphous modifications. The transformation [beta]-DySn[sub 3] [yields] [alpha]-DySn[sub 3] occurs at 608 [+-] 12 degC, and at 499 [+-]2 degC [alpha]-DySn[sub 3] decomposes to DySn[sub 2] and the tin-rich melt. The dysprosium-rich eutectic crystallizes at 1204 [+-]10 degC and contains 13 at.% tin. The solid-state solubility of tin in dysprosium is about 3 at.%, and that of dysprosium in tin is negligible.

  3. Phase diagram of colloid-rod system

    Science.gov (United States)

    Lai, S. K.; Xiao, Xuhui

    2010-01-01

    The semigrand ensemble theory [H. N. W. Lekkerkerker, W. C. K. Poon, P. N. Pusey, A. Stroobants, and P. B. Warren, Europhys. Lett. 20, 559 (1992)] in conjunction with the fundamental measure density functional theory [V. B. Warshavsky and X. Song, Phys. Rev. E 69, 061113 (2004)] are used to construct the Helmholtz free energy densities of a mixture of uncharged colloidal hard spheres and colloidal rods in its solid and liquid phases. Given these free energy density functions, we apply the free energy density minimization method [G. F. Wang and S. K. Lai, Phys. Rev. E 70, 051402 (2004)] to crosshatch the system's regions of phases in coexistence. The calculated results show that the triangular area bounded by gas-liquid, gas-solid, and liquid-solid coexisting two phases which has been called the coexistence region of gas-liquid-solid corresponds in fact to sets of two phases in coexistence. The phase boundaries which define our calculated coexistence domains compare very well with previous theoretical calculations. The relevance of the phase-diagram domains to three phases in coexistence will be discussed.

  4. Cosmological test with the QSO Hubble diagram

    CERN Document Server

    Lopez-Corredoira, M; Lusso, E; Risaliti, G

    2016-01-01

    A Hubble diagram (HD) has recently been constructed in the redshift range 099% C.L. The Quasi-Steady State Model is excluded at >95% C.L. The remaining four models (Lambda-CDM/wCDM, the R_h=ct Universe, the Friedmann open universe and a Static universe with a linear Hubble law) all pass the test. However, only Lambda-CDM/wCDM and $R_{\\rm h}=ct$ also pass the Alcock-Paczynski (AP) test. The optimized parameters in Lambda-CDM/wCDM are Omega_m=0.20^{+0.24}_{-0.20} and w_{de}=-1.2^{+1.6}_{-infinity} (the dark-energy equation-of-state). Combined with the AP test, these values become Omega_m=0.38^{+0.20}_{-0.19} and w_{de}=-0.28^{+0.52}_{-0.40}. But whereas this optimization of parameters in Lambda-CDM/wCDM creates some tension with their concordance values, the $R_{\\rm h}=ct$ Universe has the advantage of fitting the QSO and AP data without any free parameters.

  5. Diagram of Cell to Cell Communication

    Science.gov (United States)

    2002-01-01

    Diagram depicts the importance of cell-cell communication as central to the understanding of cancer growth and progression, the focus of the NASA bioreactor demonstration system (BDS-05) investigation. Microgravity studies will allow us to unravel the signaling and communication between these cells with the host and potential development of therapies for the treatment of cancer metastasis. The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. The Bioreactor is rotated to provide gentle mixing of fresh and spent nutrient without inducing shear forces that would damage the cells. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators. Credit: Emory University.

  6. Diagram of Cell to Cell Communication

    Science.gov (United States)

    2002-01-01

    Diagram depicts the importance of cell-cell communication as central to the understanding of cancer growth and progression, the focus of the NASA bioreactor demonstration system (BDS-05) investigation. Microgravity studies will allow us to unravel the signaling and communication between these cells with the host and potential development of therapies for the treatment of cancer metastasis. The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. The Bioreactor is rotated to provide gentle mixing of fresh and spent nutrient without inducing shear forces that would damage the cells. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators. Credit: Emory University.

  7. Cloning Voronoi Diagrams via Retroactive Data Structures

    CERN Document Server

    Dickerson, Matthew T; Goodrich, Michael T

    2010-01-01

    We address the problem of replicating a Voronoi diagram $V(S)$ of a planar point set $S$ by making proximity queries, which are of three possible (in decreasing order of information content): 1. the exact location of the nearest site(s) in $S$; 2. the distance to and label(s) of the nearest site(s) in $S$; 3. a unique label for every nearest site in $S$. We provide algorithms showing how queries of Type 1 and Type 2 allow an exact cloning of $V(S)$ with $O(n)$ queries and $O(n \\log^2 n)$ processing time. We also prove that queries of Type 3 can never exactly clone $V(S)$, but we show that with $O(n \\log\\frac{1}{\\epsilon})$ queries we can construct an $\\epsilon$-approximate cloning of $V(S)$. In addition to showing the limits of nearest-neighbor database security, our methods also provide one of the first natural algorithmic applications of retroactive data structures.

  8. Dynamics of the continental margins

    Energy Technology Data Exchange (ETDEWEB)

    1990-11-01

    On 18--20 June 1990, over 70 oceanographers conducting research in the ocean margins of North America attended a workshop in Virginia Beach, Virginia. The purpose of the workshop was to provide the Department of Energy with recommendations for future research on the exchange of energy-related materials between the coastal and interior ocean and the relationship between the ocean margins and global change. The workshop was designed to optimize the interaction of scientists from specific research disciplines (biology, chemistry, physics and geology) as they developed hypotheses, research questions and topics and implementation plans. The participants were given few restraints on the research they proposed other than realistic time and monetary limits. The interdisciplinary structure of the meeting promoted lively discussion and creative research plans. The meeting was divided into four working groups based on lateral, vertical, air/sea and sediment/water processes. Working papers were prepared and distributed before the meeting. During the meeting the groups revised the papers and added recommendations that appear in this report, which was reviewed by an Executive Committee.

  9. VennDiagramWeb: a web application for the generation of highly customizable Venn and Euler diagrams.

    Science.gov (United States)

    Lam, Felix; Lalansingh, Christopher M; Babaran, Holly E; Wang, Zhiyuan; Prokopec, Stephenie D; Fox, Natalie S; Boutros, Paul C

    2016-10-03

    Visualization of data generated by high-throughput, high-dimensionality experiments is rapidly becoming a rate-limiting step in computational biology. There is an ongoing need to quickly develop high-quality visualizations that can be easily customized or incorporated into automated pipelines. This often requires an interface for manual plot modification, rapid cycles of tweaking visualization parameters, and the generation of graphics code. To facilitate this process for the generation of highly-customizable, high-resolution Venn and Euler diagrams, we introduce VennDiagramWeb: a web application for the widely used VennDiagram R package. VennDiagramWeb is hosted at http://venndiagram.res.oicr.on.ca/ . VennDiagramWeb allows real-time modification of Venn and Euler diagrams, with parameter setting through a web interface and immediate visualization of results. It allows customization of essentially all aspects of figures, but also supports integration into computational pipelines via download of R code. Users can upload data and download figures in a range of formats, and there is exhaustive support documentation. VennDiagramWeb allows the easy creation of Venn and Euler diagrams for computational biologists, and indeed many other fields. Its ability to support real-time graphics changes that are linked to downloadable code that can be integrated into automated pipelines will greatly facilitate the improved visualization of complex datasets. For application support please contact Paul.Boutros@oicr.on.ca.

  10. Collaborative diagramming during problem based learning in medical education: Do computerized diagrams support basic science knowledge construction?

    Science.gov (United States)

    De Leng, Bas; Gijlers, Hannie

    2015-05-01

    To examine how collaborative diagramming affects discussion and knowledge construction when learning complex basic science topics in medical education, including its effectiveness in the reformulation phase of problem-based learning. Opinions and perceptions of students (n = 70) and tutors (n = 4) who used collaborative diagramming in tutorial groups were collected with a questionnaire and focus group discussions. A framework derived from the analysis of discourse in computer-supported collaborative leaning was used to construct the questionnaire. Video observations were used during the focus group discussions. Both students and tutors felt that collaborative diagramming positively affected discussion and knowledge construction. Students particularly appreciated that diagrams helped them to structure knowledge, to develop an overview of topics, and stimulated them to find relationships between topics. Tutors emphasized that diagramming increased interaction and enhanced the focus and detail of the discussion. Favourable conditions were the following: working with a shared whiteboard, using a diagram format that facilitated distribution, and applying half filled-in diagrams for non-content expert tutors and\\or for heterogeneous groups with low achieving students. The empirical findings in this study support the findings of earlier more descriptive studies that diagramming in a collaborative setting is valuable for learning complex knowledge in medicine.

  11. In Defense of an Accelerating Universe: Model Insensitivity of the Hubble Diagram

    CERN Document Server

    Ringermacher, H I

    2016-01-01

    Nielsen, Guffanti and Sarkar, in their recent Nature article, present a detailed argument that the evidence for cosmic acceleraton is marginal and that a coasting universe model, namely that of the "Milne Universe", fits the same SNe Ia data set in a Hubble diagram (distance modulus vs. redshift) nearly as well. However, we find that when the SNe data, the LCDM model and Milne model are plotted as scale factor vs. linear cosmological time in a model-independent fashion the two resulting curves separate significantly above the noise making it exceptionally clear that the universe is accelerating and the Milne model cannot fit the time-data. In this plot, the Milne model generates a straight line, while LCDM continues to show an excellent fit to acceleration. The separation of these two models on this type of plot demonstrates the efficacy of this new plot procedure.

  12. The use of Ternary Diagrams in the Analysis and the Mathematical Modeling of Bank Assets Structure

    Directory of Open Access Journals (Sweden)

    Ramona Mariana CALINICA

    2012-04-01

    Full Text Available The objectives pursued in this paper are: to obtain by means of ternary diagrams imagistic representations of the structure of assets in credit banking institutions operating in Romania in case of stability, turbulence and intense manifestation of the crisis; identifying functional discontinuities and achieve a comparative database. The ultimate goal of this paper is reporting the results obtained from comparative database to find out what signals preceding a turbulent situation in the banking sector and how far away is the banking system by the normal situation.

  13. Determination of the Fe-rich portion of the Fe-Ni-C phase diagram

    Science.gov (United States)

    Romig, A. D., Jr.; Goldstein, J. I.

    1978-01-01

    The iron-enriched section of the phase diagram for the ternary alloy Fe-Ni-C of various compositions is determined at 773, 873, 923, and 1003 C. The two-phase tie lines and three-phase tie triangles are measured by electron microprobe analyses. Tie lines in samples without bulk equilibrium are obtained by extrapolated interface compositions under the assumption of local equilibrium at the interface. It is shown that Ni addition somewhat reduces carbon solubility in austenite while decreasing the stability of the carbide phase. In particular, the carbide is always poor in Ni relative to the coexisting metal phase(s).

  14. Polynomial Approach and Non-linear Analysis for a Traffic Fundamental Diagram

    Directory of Open Access Journals (Sweden)

    Oscar A. Rosas-Jaimes

    2016-08-01

    Full Text Available Vehicular traffic can be modelled as a dynamic discrete form. As in many dynamic systems, the parameters modelling traffic can produce a number of different trajectories or orbits, and it is possible to depict different flow situations, including chaotic ones. In this paper, an approach to the wellknown density-flow fundamental diagram is suggested, using an analytical polynomial technique, in which coefficients are taken from significant values acting as the parameters of the traffic model. Depending on the values of these parameters, it can be seen how the traffic flow changes from stable endpoints to chaotic trajectories, with proper analysis in their stability features.

  15. Interplay between diffusive and displacive phase transformations: time-temperature-transformation diagrams and microstructures.

    Science.gov (United States)

    Bouville, Mathieu; Ahluwalia, Rajeev

    2006-08-01

    Materials which can undergo extremely fast displacive transformations as well as very slow diffusive transformations are studied using a Ginzburg-Landau framework. This simple model captures the essential physics behind microstructure formation and time-temperature-transformation diagrams in alloys such as steels. It also predicts the formation of mixed microstructures by an interplay between diffusive and displacive mechanisms. The intrinsic volume changes associated with the transformations stabilize mixed microstructures such as martensite-retained austenite (responsible for the existence of a martensite finish temperature) and martensite-pearlite.

  16. Oak Ridge National Laboratory Technology Logic Diagram. Volume 2, Technology Logic Diagram: Part B, Remedial Action

    Energy Technology Data Exchange (ETDEWEB)

    1993-09-01

    The Oak Ridge National Laboratory Technology Logic Diagram (TLD) was developed to provide a decision support tool that relates environmental restoration (ER) and waste management (WM) problems at Oak Ridge National Laboratory (ORNL) to potential technologies that can remediate these problems. The TLD identifies the research, development, demonstration, testing, and evaluation needed to develop these technologies to a state that allows technology transfer and application to decontamination and decommissioning (D&D), remedial action (RA), and WM activities. The TLD consists of three fundamentally separate volumes: Vol. 1 (Technology Evaluation), Vol. 2 (Technology Logic Diagram), and Vol. 3 (Technology Evaluation Data Sheets). Part A of Vols. 1. and 2 focuses on D&D. Part B of Vols. 1 and 2 focuses on the RA of contaminated facilities. Part C of Vols. 1 and 2 focuses on WM. Each part of Vol. 1 contains an overview of the TLD, an explanation of the program-specific responsibilities, a review of identified technologies, and the rankings of remedial technologies. Volume 2 (Pts. A, B, and C) contains the logic linkages among EM goals, environmental problems, and the various technologies that have the potential to solve these problems. Volume 3 (Pts. A, B, and C) contains the TLD data sheets. Remedial action is the focus of Vol. 2, Pt. B, which has been divided into the three necessary subelements of the RA: characterization, RA, and robotics and automation. Each of these sections address general ORNL problems, which are then broken down by problem area/constituents and linked to potential remedial technologies. The diagrams also contain summary information about a technology`s status, its science and technology needs, and its implementation needs.

  17. Forest Dynamics at the Missouri Ozark Forest Ecosystem Project viewed through stocking diagrams

    Science.gov (United States)

    David R. Larsen; John M. Kabrick; Stephen R. Shifley; Randy G. Jensen

    2017-01-01

    Stocking diagrams come in two forms, the Gingrich diagram and the density management diagram. While they both present the same information about a forest stand, they each provide a different perspective on the data being displayed. Density management diagrams have been around since the 1930s and the Gingrich diagram has been around since the 1960s, but applications of...

  18. Stability Analysis of the LHC Cables for Transient Heat Depositions

    CERN Document Server

    Granieri, P P; Xydi, P; Baudouy, B; Bocian, D; Bottura, L; Breschi, M; Siemko, A

    2008-01-01

    The commissioning and the exploitation of the LHC require a good knowledge of the stability margins of the superconducting magnets with respect to beam induced heat depositions. Previous studies showed that simple numerical models are suitable to carry out stability calculations of multi-strands cables, and highlighted the relevance of the heat transfer model with the surrounding helium. In this paper we present a systematic scan of the stability margin of all types of LHC cables working at 1.9 Kagainst transient heat depositions. We specifically discuss the dependence of the stability margin on the parameters of the model, which provide an estimate of the uncertainty of the values quoted. The stability margin calculations have been performed using a zero-dimensional (0-D) numerical model, and a cooling model taking into account the relevant helium phases which may appear during a stability experiment: it includes Kapitza thermal resistance in superfluid He, boundary layer formation and heat transfer in He I,...

  19. Equilibrium p-T Phase Diagram of Boron: Experimental Study and Thermodynamic Analysis

    Science.gov (United States)

    Solozhenko, Vladimir L.; Kurakevych, Oleksandr O.

    2013-01-01

    Solid-state phase transformations and melting of high-purity crystalline boron have been in situ and ex situ studied at pressures to 20 GPa in the 1500–2500 K temperature range where diffusion processes become fast and lead to formation of thermodynamically stable phases. The equilibrium phase diagram of boron has been constructed based on thermodynamic analysis of experimental and literature data. The high-temperature part of the diagram contains p-T domains of thermodynamic stability of rhombohedral β-B106, orthorhombic γ-B28, pseudo-cubic (tetragonal) t'-B52, and liquid boron (L). The positions of two triple points have been experimentally estimated, i.e. β–t'–L at ~ 8.0 GPa and ~ 2490 K; and β–γ–t' at ~ 9.6 GPa and ~ 2230 K. Finally, the proposed phase diagram explains all thermodynamic aspects of boron allotropy and significantly improves our understanding of the fifth element. PMID:23912523

  20. Study of the periodic ferroresonance in the electrical power networks by bifurcation diagrams

    Energy Technology Data Exchange (ETDEWEB)

    Ben Amar, F. [Department of Technology, Preparatory Institute for Engineering Studies of Sfax (IPEIS), Menzel Chaker Road, km 0.5, BP 1172, 3018 Sfax (Tunisia); Electric Network and Machines Research Unit, INSAT (Tunisia); Dhifaoui, R. [Electric Network and Machines Research Unit, INSAT (Tunisia)

    2011-01-15

    The principal contribution of this article is to determine the existence zones of the various periodic ferroresonant modes (fundamental, harmonic and subharmonic) intervening in the electrical power network. The bifurcation diagrams are used for this purpose. To be able to plot a bifurcation diagram of a particular solution, it is initially necessary to locate this solution and then to follow it according to a bifurcation parameter. The developed computation code, resulting from the implementation of the Galerkin method jointly with the pseudo-arclength continuation method, has proved to be a powerful and reliable tool to construct these bifurcation diagrams. Indeed, it enables the electrical power network operators to better understand the problems of the phenomenon which had been observed in its network and to foresee new ferroresonance cases. Applied to the single-phase ferroresonant circuits, both series and parallel, we have been able to easily calculate the existence zones of these modes, as well as the stability limits of the system on ranges of broad variation of the parameters. Several results obtained numerically by software MATLAB, as from the real cases, are presented and commented upon. (author)

  1. Experimental and computed phase diagrams of the Fe–Re system.

    Science.gov (United States)

    Breidi, A; Andasmas, M; Crivello, J-C; Dupin, N; Joubert, J-M

    2014-12-03

    In order to clarify controversial reports on the Fe-Re phase diagram, a new experimental investigation has been carried out. Three intermetallic phases have been evidenced, including the new report of the P phase found for the first time in a binary system. The phase relations involving the σ phase were established. In parallel, a first-principles study has been performed which provided the heat of formation of every ordered configuration for four intermetallic phases (D8(b), A12, A13 and P). The mixing energy of solid solutions (fcc, bcc, hcp) was calculated using the special quasi-random structure method. Calculations were performed with the help of the density functional theory, with and without spin polarization. From these results, in the frame of the Compound Energy Formalism using the Bragg-Williams approximation, the Fe-Re phase diagram has been computed without the use of adjustable parameters. Different thermodynamic parameters obtained experimentally and theoretically, as the site occupancies, are compared. The computed phase diagram presents several differences with the experimental one. To understand these differences, the influence of several parameters on the phase stability, such as the magnetic contribution has been evaluated.

  2. Classical Process diagrams and Service oriented Architecture

    Directory of Open Access Journals (Sweden)

    Milan Mišovič

    2013-01-01

    services communicate with each other. The communication can involve either simple data or it could two or more services coordinating some activity. From the above mentioned we can pronounce a brief description of SOA. “SOA is an architectural style for consistency of business process logic and service architecture of the target software.”It is a complex of means for solution of special analysis, design, and integration of enterprise applications based on the use of enterprise services. The service solutions of the classic business process logic are, of course, based on the application of at least seven key principles of SOA (free relations, service contract, autonomy, abstraction, reusing, composition, no states. Key attributes of SOA are verbally described in (Erl, 2006. They are so important that a separate article should be devoted to their nature and formalization. On the other hand, there is also clear that each service solution of business logic should respect the principles published in SOA Manifesto, 2009, which are essentially derived from the key principles of SOA.In many publications there are given the SOA reference models usually composed of several layers (presentation layer, business process layer, composite services layer, application layer giving a meta idea of SOA implementation. Perfect knowledge of the business process logic is a necessary condition for the development of a proper service solution. The different types of business processes should be described in the necessary details and contexts.Interestingly, the SOA paradigm does not provide its own method of finding and describing business processes by giving a layered transparent business process diagram. On the other hand, the methodology provides deep understanding of not only the characteristics of services, but also their functionality and implementation of the key principles of SOA (Erl, 2006.Let us assume that the required process diagrams can be achieved by using some of the advanced

  3. Homotopy theory of modules over diagrams of rings

    Directory of Open Access Journals (Sweden)

    J. P. C. Greenlees

    2014-09-01

    Full Text Available Given a diagram of rings, one may consider the category of modules over them. We are interested in the homotopy theory of categories of this type: given a suitable diagram of model categories ℳ( (as runs through the diagram, we consider the category of diagrams where the object ( at comes from ℳ(. We develop model structures on such categories of diagrams and Quillen adjunctions that relate categories based on different diagram shapes. Under certain conditions, cellularizations (or right Bousfield localizations of these adjunctions induce Quillen equivalences. As an application we show that a cellularization of a category of modules over a diagram of ring spectra (or differential graded rings is Quillen equivalent to modules over the associated inverse limit of the rings. Another application of the general machinery here is given in work by the authors on algebraic models of rational equivariant spectra. Some of this material originally appeared in the preprint “An algebraic model for rational torus-equivariant stable homotopy theory”, arXiv:1101.2511, but has been generalized here.

  4. Magnetic unmixing of first-order reversal curve diagrams using principal component analysis

    Science.gov (United States)

    Lascu, Ioan; Harrison, Richard J.; Li, Yuting; Muraszko, Joy R.; Channell, James E. T.; Piotrowski, Alexander M.; Hodell, David A.

    2015-09-01

    We describe a quantitative magnetic unmixing method based on principal component analysis (PCA) of first-order reversal curve (FORC) diagrams. For PCA, we resample FORC distributions on grids that capture diagnostic signatures of single-domain (SD), pseudosingle-domain (PSD), and multidomain (MD) magnetite, as well as of minerals such as hematite. Individual FORC diagrams are recast as linear combinations of end-member (EM) FORC diagrams, located at user-defined positions in PCA space. The EM selection is guided by constraints derived from physical modeling and imposed by data scatter. We investigate temporal variations of two EMs in bulk North Atlantic sediment cores collected from the Rockall Trough and the Iberian Continental Margin. Sediments from each site contain a mixture of magnetosomes and granulometrically distinct detrital magnetite. We also quantify the spatial variation of three EM components (a coarse silt-sized MD component, a fine silt-sized PSD component, and a mixed clay-sized component containing both SD magnetite and hematite) in surficial sediments along the flow path of the North Atlantic Deep Water (NADW). These samples were separated into granulometric fractions, which helped constrain EM definition. PCA-based unmixing reveals systematic variations in EM relative abundance as a function of distance along NADW flow. Finally, we apply PCA to the combined data set of Rockall Trough and NADW sediments, which can be recast as a four-EM mixture, providing enhanced discrimination between components. Our method forms the foundation of a general solution to the problem of unmixing multicomponent magnetic mixtures, a fundamental task of rock magnetic studies.

  5. Milling Stability Analysis Based on Chebyshev Segmentation

    Science.gov (United States)

    HUANG, Jianwei; LI, He; HAN, Ping; Wen, Bangchun

    2016-09-01

    Chebyshev segmentation method was used to discretize the time period contained in delay differential equation, then the Newton second-order difference quotient method was used to calculate the cutter motion vector at each time endpoint, and the Floquet theory was used to determine the stability of the milling system after getting the transfer matrix of milling system. Using the above methods, a two degree of freedom milling system stability issues were investigated, and system stability lobe diagrams were got. The results showed that the proposed methods have the following advantages. Firstly, with the same calculation accuracy, the points needed to represent the time period are less by the Chebyshev Segmentation than those of the average segmentation, and the computational efficiency of the Chebyshev Segmentation is higher. Secondly, if the time period is divided into the same parts, the stability lobe diagrams got by Chebyshev segmentation method are more accurate than those of the average segmentation.

  6. Mechanical stability of bipolar spindle assembly

    CERN Document Server

    Malgaretti, Paolo

    2016-01-01

    Assembly and stability of mitotic spindle is governed by the interplay of various intra-cellular forces, e.g. the forces generated by motor proteins by sliding overlapping anti-parallel microtubules (MTs) polymerized from the opposite centrosomes, the interaction of kinetochores with MTs, and the interaction of MTs with the chromosomes arms. We study the mechanical behavior and stability of spindle assembly within the framework of a minimal model which includes all these effects. For this model, we derive a closed--form analytical expression for the force acting between the centrosomes as a function of their separation distance and we show that an effective potential can be associated with the interactions at play. We obtain the stability diagram of spindle formation in terms of parameters characterizing the strength of motor sliding, repulsive forces generated by polymerizing MTs, and the forces arising out of interaction of MTs with kinetochores. The stability diagram helps in quantifying the relative effec...

  7. Determination of all feasible robust PID controllers for open-loop unstable plus time delay processes with gain margin and phase margin specifications.

    Science.gov (United States)

    Wang, Yuan-Jay

    2014-03-01

    This paper proposes a novel alternative method to graphically compute all feasible gain and phase margin specifications-oriented robust PID controllers for open-loop unstable plus time delay (OLUPTD) processes. This method is applicable to general OLUPTD processes without constraint on system order. To retain robustness for OLUPTD processes subject to positive or negative gain variations, the downward gain margin (GM(down)), upward gain margin (GM(up)), and phase margin (PM) are considered. A virtual gain-phase margin tester compensator is incorporated to guarantee the concerned system satisfies certain robust safety margins. In addition, the stability equation method and the parameter plane method are exploited to portray the stability boundary and the constant gain margin (GM) boundary as well as the constant PM boundary. The overlapping region of these boundaries is graphically determined and denotes the GM and PM specifications-oriented region (GPMSOR). Alternatively, the GPMSOR characterizes all feasible robust PID controllers which achieve the pre-specified safety margins. In particular, to achieve optimal gain tuning, the controller gains are searched within the GPMSOR to minimize the integral of the absolute error (IAE) or the integral of the squared error (ISE) performance criterion. Thus, an optimal PID controller gain set is successfully found within the GPMSOR and guarantees the OLUPTD processes with a pre-specified GM and PM as well as a minimum IAE or ISE. Consequently, both robustness and performance can be simultaneously assured. Further, the design procedures are summarized as an algorithm to help rapidly locate the GPMSOR and search an optimal PID gain set. Finally, three highly cited examples are provided to illustrate the design process and to demonstrate the effectiveness of the proposed method.

  8. Bifurcation diagrams in relation to synchronization in chaotic systems

    Indian Academy of Sciences (India)

    Debabrata Dutta; Sagar Chakraborty

    2010-06-01

    We numerically study some of the three-dimensional dynamical systems which exhibit complete synchronization as well as generalized synchronization to show that these systems can be conveniently partitioned into equivalent classes facilitating the study of bifurcation diagrams within each class. We demonstrate how bifurcation diagrams may be helpful in predicting the nature of the driven system by knowing the bifurcation diagram of driving system and vice versa. The study is extended to include the possible generalized synchronization between elements of two different equivalent classes by taking the Rössler-driven-Lorenz-system as an example.

  9. Thermodynamic equilibrium diagram of the chlorine-titanium system

    Institute of Scientific and Technical Information of China (English)

    DU Ailing; GUO Xiaofei; ZHANG Heming; LIU Jiang

    2005-01-01

    The chemical and electrochemical equilibria of the chlorine-titanium system in the presence of gaseous phase were investigated. Many species, which consisted of chlorine and titanium, were considered. Various thermodynamic equilibria were calculated in the different pressures at different temperatures. The calculated results were shown as log p-1/T and E-T diagrams. These diagrams may be used as important tools for corrosion study and titanium production. The diagrams are also used to thermodynamically determine the existence areas of various species and so on.

  10. Does the butterfly diagram indicate asolar flux-transport dynamo?

    CERN Document Server

    Schüssler, M

    2004-01-01

    We address the question whether the properties of the observed latitude-time diagram of sunspot occurence (the butterfly diagram) provide evidence for the operation of a flux-transport dynamo, which explains the migration of the sunspot zones and the period of the solar cycle in terms of a deep equatorward meridional flow. We show that the properties of the butterfly diagram are equally well reproduced by a conventional dynamo model with migrating dynamo waves, but without transport of magnetic flux by a flow. These properties seem to be generic for an oscillatory and migratory field of dipole parity and thus do not permit an observational distinction between different dynamo approaches.

  11. Linkage intensity learning approach with genetic algorithm for causality diagram

    Institute of Scientific and Technical Information of China (English)

    WANG Cheng-liang; CHEN Juan-juan

    2007-01-01

    The causality diagram theory, which adopts graphical expression of knowledge and direct intensity of causality, overcomes some shortages in belief network and has evolved into a mixed causality diagram methodology for discrete and continuous variable. But to give linkage intensity of causality diagram is difficult, particularly in many working conditions in which sampling data are limited or noisy. The classic learning algorithm is hard to be adopted. We used genetic algorithm to learn linkage intensity from limited data. The simulation results demonstrate that this algorithm is more suitable than the classic algorithm in the condition of sample shortage such as space shuttle's fault diagnoisis.

  12. Geodesic Witten diagrams with an external spinning field

    Science.gov (United States)

    Nishida, Mitsuhiro; Tamaoka, Kotaro

    2017-05-01

    We explore AdS/CFT correspondence between geodesic Witten diagrams and conformal blocks (conformal partial waves) with an external symmetric traceless tensor field. We derive an expression for the conformal partial wave with an external spin-1 field and show that this expression is equivalent to the amplitude of the geodesic Witten diagram. We also show the equivalence by using a conformal Casimir equation in embedding formalism. Furthermore, we extend the construction of the amplitude of the geodesic Witten diagram to an external arbitrary symmetric traceless tensor field. We show that our construction agrees with the known result of the conformal partial waves.

  13. Geodesic Witten diagrams with an external spinning field

    CERN Document Server

    Nishida, Mitsuhiro

    2016-01-01

    We explore AdS/CFT correspondence between geodesic Witten diagrams and conformal blocks (conformal partial waves) with an external symmetric traceless tensor field. We derive an expression for the conformal partial wave with an external spin-1 field and show that this expression is equivalent to the amplitude of the geodesic Witten diagram. We also show the equivalence by using conformal Casimir equation in embedding formalism. Furthermore, we extend the construction of the amplitude of the geodesic Witten diagram to an external arbitrary symmetric traceless tensor field. We show our construction agrees with the known result of the conformal partial waves.

  14. Dynamic programming in in uence diagrams with decision circuits

    CERN Document Server

    Shachter, Ross D

    2012-01-01

    Decision circuits perform efficient evaluation of influence diagrams, building on the ad- vances in arithmetic circuits for belief net- work inference [Darwiche, 2003; Bhattachar- jya and Shachter, 2007]. We show how even more compact decision circuits can be con- structed for dynamic programming in influ- ence diagrams with separable value functions and conditionally independent subproblems. Once a decision circuit has been constructed based on the diagram's "global" graphical structure, it can be compiled to exploit "lo- cal" structure for efficient evaluation and sen- sitivity analysis.

  15. 76 FR 54787 - Outer Continental Shelf Official Protraction Diagram, Lease Maps, and Supplemental Official Outer...

    Science.gov (United States)

    2011-09-02

    ... Bureau of Ocean Energy Management, Regulation and Enforcement Outer Continental Shelf Official Protraction Diagram, Lease Maps, and Supplemental Official Outer Continental Shelf Block Diagrams AGENCY... revised North American Datum of 1927 (NAD 27) Outer Continental Shelf Official Protraction Diagram,...

  16. 76 FR 2919 - Outer Continental Shelf Official Protraction Diagram and Supplemental Official Outer Continental...

    Science.gov (United States)

    2011-01-18

    ... Bureau of Ocean Energy Management, Regulation and Enforcement Outer Continental Shelf Official Protraction Diagram and Supplemental Official Outer Continental Shelf Block Diagrams AGENCY: Bureau of Ocean... American Datum of 1983 (NAD 83) Outer Continental Shelf Official Protraction Diagram and...

  17. Ferrian Ilmenites: Investigating the Magnetic Phase Diagram

    Science.gov (United States)

    Lagroix, F.

    2007-12-01

    The main objective of this study is to investigate the magnetic phase changes within the hematite-ilmenite solid solution, yFeTiO3·(1-y)·Fe2O3. Two sets of synthetic ferrian ilmenites of y-values equal to 0.7, 0.8, 0.9, and 1.0 were available for this study. As currently drawn, the magnetic phase diagram, proposed by Ishikawa et al. [1985, J. Phys. Soc. Jpn. v.54, 312-325], predicts for increasing y values (0.5

  18. Performance Evaluation of Portfolios with Margin Requirements

    OpenAIRE

    Hui Ding; Zhongbao Zhou; Helu Xiao; Chaoqun Ma; Wenbin Liu

    2014-01-01

    In financial markets, short sellers will be required to post margin to cover possible losses in case the prices of the risky assets go up. Only a few studies focus on the optimization and performance evaluation of portfolios in the presence of margin requirements. In this paper, we investigate the theoretical foundation of DEA (data envelopment analysis) approach to evaluate the performance of portfolios with margin requirements from a different perspective. Under the mean-variance framework,...

  19. A quality improvement tool - driver diagram: a model of driver diagram to reduce primary caesarean section rates

    Directory of Open Access Journals (Sweden)

    Naima Fathima

    2016-05-01

    Results: Various quality improvement tools can be used in the clinical context. Among them, driver diagram is most widely used at the start of an improvement initiative. The driver diagram in this article shows its applicability in one of the clinical aspects of obstetrics, to reduce primary caesarean section rates. Conclusions: Driver diagram is an easy and a simple tool widely used in quality improvement activities. It is essential to use at the beginning of improvement initiatives. [Int J Res Med Sci 2016; 4(5.000: 1339-1342

  20. Bubble diagram through the Symmetries of Feynman Integrals method

    CERN Document Server

    Kol, Barak

    2016-01-01

    The Symmetries of Feynman Integrals method (SFI) associates a natural Lie group with any diagram, depending only on its topology. The group acts on parameter space and the method determines the integral's dependence within group orbits. This paper analyzes the bubble diagram, namely the 1-loop propagator diagram, through the SFI method. This is the first diagram with external legs to be analyzed within SFI, and the method is generalized to include this case. The set of differential equation is obtained. In order to solve it the set is transformed into partial invariants variables. The equations are integrated to reproduce the integral's value. This value is interpreted in terms of triangle geometry partially inspired by earlier papers.

  1. Alaska NAD 83 Official Protraction Diagram (OPD) Outlines

    Data.gov (United States)

    Bureau of Ocean Energy Management, Department of the Interior — This data set contains Official Protraction Diagram (OPD) outlines in ESRI shapefile format. At lower latitudes (0-48 degrees) OPDs are 1 degree in latitude by 2...

  2. Alaska NAD 83 Official Protraction Diagram (OPD) Outlines

    Data.gov (United States)

    Bureau of Ocean Energy Management, Department of the Interior — This data set contains Official Protraction Diagram (OPD) outlines in ESRI shapefile format. At lower latitudes (0-48 degrees) OPDs are 1 degree in latitude by 2...

  3. Outer Continental Shelf Official Protraction Diagrams - Alaska Region NAD 83

    Data.gov (United States)

    Bureau of Ocean Energy Management, Department of the Interior — This data set contains Official Protraction Diagram (OPD) outlines in ESRI shapefile format. At lower latitudes (0-48 degrees) OPDs are 1 degree in latitude by 2...

  4. Atlantic NAD 83 Official Protraction Diagram (OPD) Images

    Data.gov (United States)

    Bureau of Ocean Energy Management, Department of the Interior — This data set contains Official Protraction Diagrams (OPDs) in Adobe PDF format. Atlantic Region OPDs are approximately 2 degrees wide by one degree high. OPDs are...

  5. Official Protraction Diagram and Leasing Map Boundaries - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer shows official protraction diagram (OPD) and leasing map boundaries covering areas of the Outer Continental Shelf (OCS) within Federal jurisdiction....

  6. Pacific NAD 83 Supplemental Official Protraction Diagram (OPD) Images

    Data.gov (United States)

    Bureau of Ocean Energy Management, Department of the Interior — This data set contains Supplemental Official OCS Block Diagram (SOBD) images in Adobe pdf format for areas within the BOEM Pacific Region. Each SOBD describes a...

  7. Alaska NAD 83 Supplemental Official Protraction Diagram (OPD) Images

    Data.gov (United States)

    Bureau of Ocean Energy Management, Department of the Interior — This data set contains Supplemental Official OCS Block Diagram (SOBD) images in Adobe pdf format for areas within the BOEM Alaska Region. Each SOBD describes a...

  8. Pacific NAD 83 Official Protraction Diagram (OPD) Images

    Data.gov (United States)

    Bureau of Ocean Energy Management, Department of the Interior — This data set contains Official Protraction Diagrams (OPDs) in Adobe PDF format. Pacific Region OPDs are approximately 2 degrees wide by one degree high. OPDs are...

  9. Alaska NAD 83 Composite Block Diagram (CBD) Images

    Data.gov (United States)

    Bureau of Ocean Energy Management, Department of the Interior — This data set contains Composite Block Diagram (CBD) images in Adobe pdf format for areas within the BOEM Alaska Region. Each CBD describes a single block within an...

  10. Atlantic NAD 83 Supplemental Official OCS Block Diagram (SOBD) Images

    Data.gov (United States)

    Bureau of Ocean Energy Management, Department of the Interior — This data set contains Supplemental Official OCS Block Diagram (SOBD) images in Adobe pdf format for areas within the BOEM Atlantic Region. Each SOBD describes a...

  11. Alaska NAD 83 Official Protraction Diagram (OPD) Images

    Data.gov (United States)

    Bureau of Ocean Energy Management, Department of the Interior — This data set contains Official Protraction Diagrams (OPDs) in Adobe PDF format. Atlantic Region OPDs are approximately 2 degrees wide by one degree high. OPDs are...

  12. Heuristic Diagrams as a Tool to Teach History of Science

    Science.gov (United States)

    Chamizo, José A.

    2012-05-01

    The graphic organizer called here heuristic diagram as an improvement of Gowin's Vee heuristic is proposed as a tool to teach history of science. Heuristic diagrams have the purpose of helping students (or teachers, or researchers) to understand their own research considering that asks and problem-solving are central to scientific activity. The left side originally related in Gowin's Vee with philosophies, theories, models, laws or regularities now agrees with Toulmin's concepts (language, models as representation techniques and application procedures). Mexican science teachers without experience in science education research used the heuristic diagram to learn about the history of chemistry considering also in the left side two different historical times: past and present. Through a semantic differential scale teachers' attitude to the heuristic diagram was evaluated and its usefulness was demonstrated.

  13. The Compressibility of Checkerboard Surfaces of Link Diagrams

    Institute of Scientific and Technical Information of China (English)

    Zhi Qiang BAO

    2007-01-01

    Consider the checkerboard surfaces defined by some link diagrams. When they are notorientable, one considers the boundary surfaces of small regular neighborhoods of them. This articlestudies the compressibility problem of these kinds of surfaces in the link complements. The problemis solved by devising a normalization theory for the compressing discs, which brings up an algorithmto read out compressibility directly from the link diagrams. As an application of the algorithm, thecompressibility changes under Reidermeister moves are studied. Diagrams from the knot tables arealso studied, and surprisingly, some of them are shown to define completely compressible surfaces ofthis kind. Infinitely many examples of non-alternating knot diagrams with incompressible surfaces ofthis kind are also constructed.

  14. Finite Rank Bratteli Diagrams and their Invariant Measures

    CERN Document Server

    Bezuglyi, Sergey; Medynets, Konstantin; Solomyak, Boris

    2010-01-01

    In this paper we study ergodic measures on non-simple Bratteli diagrams of finite rank that are invariant with respect to the cofinal equivalence relation. We describe the structure of finite rank diagrams and prove that every ergodic invariant measure (finite or infinite) is an extension of a finite ergodic measure defined on a simple subdiagram. We find some algebraic criteria in terms of entries of incidence matrices and their norms under which such an extension remains a finite measure. Furthermore, the support of every ergodic measure is explicitly determined. We also give an algebraic condition for a diagram to be uniquely ergodic. It is proved that Vershik maps (not necessarily continuous) on finite rank Bratteli diagrams cannot be strongly mixing and always have zero entropy with respect to any finite ergodic invariant measure. A number of examples illustrating the established results is included.

  15. Geometrical approach to the evaluation of multileg Feynman diagrams

    Energy Technology Data Exchange (ETDEWEB)

    Davydychev, A.I. [Department of Physics, University of Mainz, Mainz (Germany); Delbourgo, R. [Physics Department, University of Tasmania, Hobart, Tasmania (Australia)

    1998-10-01

    A connection between one-loop N-point Feynman diagrams and certain geometrical quantities in non-Euclidean geometry is discussed. A geometrical way to calculate the corresponding Feynman integrals is considered. (author)

  16. Lyapunov exponent diagrams of a 4-dimensional Chua system.

    Science.gov (United States)

    Stegemann, Cristiane; Albuquerque, Holokx A; Rubinger, Rero M; Rech, Paulo C

    2011-09-01

    We report numerical results on the existence of periodic structures embedded in chaotic and hyperchaotic regions on the Lyapunov exponent diagrams of a 4-dimensional Chua system. The model was obtained from the 3-dimensional Chua system by the introduction of a feedback controller. Both the largest and the second largest Lyapunov exponents were considered in our colorful Lyapunov exponent diagrams, and allowed us to characterize periodic structures and regions of chaos and hyperchaos. The shrimp-shaped periodic structures appear to be malformed on some of Lyapunov exponent diagrams, and they present two different bifurcation scenarios to chaos when passing the boundaries of itself, namely via period-doubling and crisis. Hyperchaos-chaos transition can also be observed on the Lyapunov exponent diagrams for the second largest exponent.

  17. Phase diagrams of binary mixtures of oppositely charged colloids.

    Science.gov (United States)

    Bier, Markus; van Roij, René; Dijkstra, Marjolein

    2010-09-28

    Phase diagrams of binary mixtures of oppositely charged colloids are calculated theoretically. The proposed mean-field-like formalism interpolates between the limits of a hard-sphere system at high temperatures and the colloidal crystals which minimize Madelung-like energy sums at low temperatures. Comparison with computer simulations of an equimolar mixture of oppositely charged, equally sized spheres indicate semiquantitative accuracy of the proposed formalism. We calculate global phase diagrams of binary mixtures of equally sized spheres with opposite charges and equal charge magnitude in terms of temperature, pressure, and composition. The influence of the screening of the Coulomb interaction upon the topology of the phase diagram is discussed. Insight into the topology of the global phase diagram as a function of the system parameters leads to predictions on the preparation conditions for specific binary colloidal crystals.

  18. Phase diagrams of binary crystalline-crystalline polymer blends.

    Science.gov (United States)

    Matkar, Rushikesh A; Kyu, Thein

    2006-08-17

    A thermodynamically self-consistent theory has been developed to establish binary phase diagrams for two-crystalline polymer blends by taking into consideration all interactions including amorphous-amorphous, crystal-amorphous, amorphous-crystal, and crystal-crystal interactions. The present theory basically involves combination of the Flory-Huggins free energy for amorphous-amorphous isotropic mixing and the Landau free energy of polymer solidification (e.g., crystallization) of the crystalline constituents. The self-consistent solution via minimization of the free energy of the mixture affords determination of eutectic, peritectic, and azeotrope phase diagrams involving various coexistence regions such as liquid-liquid, liquid-solid, and solid-solid coexistence regions bound by liquidus and solidus lines. To validate the present theory, the predicted eutectic phase diagrams have been compared with the reported experimental binary phase diagrams of blends such as polyethylene fractions as well as polycaprolactone/trioxane mixtures.

  19. A dialogue about protein crystallization and phase diagrams.

    Science.gov (United States)

    Asherie, Neer

    2012-07-01

    A lighthearted researcher and a disheartened student discuss the challenges of protein crystallization and how phase diagrams can be used to address these challenges. The student feels a little better afterwards, but many proteins remain uncrystallized.

  20. Adding Value to Force Diagrams: Representing Relative Force Magnitudes

    Science.gov (United States)

    Wendel, Paul

    2011-05-01

    Nearly all physics instructors recognize the instructional value of force diagrams, and this journal has published several collections of exercises to improve student skill in this area.1-4 Yet some instructors worry that too few students perceive the conceptual and problem-solving utility of force diagrams,4-6 and over recent years a rich variety of approaches has been proposed to add value to force diagrams. Suggestions include strategies for identifying candidate forces,6,7 emphasizing the distinction between "contact" and "noncontact" forces,5,8 and the use of computer-based tutorials.9,10 Instructors have suggested a variety of conventions for constructing force diagrams, including approaches to arrow placement and orientation2,11-13 and proposed notations for locating forces or marking action-reaction force pairs.8,11,14,15