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Sample records for weakly bound systems

  1. Weakly bound systems, continuum effects, and reactions

    CERN Document Server

    Jaganathen, Y; Ploszajczak, M

    2012-01-01

    Structure of weakly bound/unbound nuclei close to particle drip lines is different from that around the valley of beta stability. A comprehensive description of these systems goes beyond standard Shell Model and demands an open quantum system description of the nuclear many-body system. We approach this problem using the Gamow Shell Model which provides a fully microscopic description of bound and unbound nuclear states, nuclear decays, and reactions. We present in this paper the first application of the GSM for a description of the elastic and inelastic scattering of protons on 6He.

  2. Regularity of weak solutions to the Landau-Lifshitz system in bounded regular domains

    Directory of Open Access Journals (Sweden)

    Kevin Santugini-Repiquet

    2007-10-01

    Full Text Available In this paper, we study the regularity, on the boundary, of weak solutions to the Landau-Lifshitz system in the framework of the micromagnetic model in the quasi-static approximation. We establish the existence of global weak solutions to the Landau-Lifshitz system whose tangential space gradient on the boundary is square integrable.

  3. Weakly bound states of two- and three-boson systems in the crossover from two to three dimensions

    DEFF Research Database (Denmark)

    Yamashita, Marcelo; Bellotti, Filipe Furlan; Frederico, Tobias

    2015-01-01

    . In this paper we study weakly bound states of non-relativistic two and three boson systems when passing continuously from a three (3D) to a two-dimensional (2D) regime within a 'squeezed dimension' model. We use periodic boundary conditions to derive a surprisingly simple form of the three-boson Schr{\\"o}dinger...... equation in momentum space that we solve numerically. Our results show a distinct dimensional crossover as three-boson states will either disappear into the continuum or merge with a 2D counterpart, and also a series of sharp transitions in the ratios of three-body and two-body energies from being purely 2...

  4. Collisional properties of weakly bound heteronuclear dimers

    NARCIS (Netherlands)

    Marcelis, B.; Kokkelmans, S.J.J.M.F.; Shlyapnikov, G.V.; Petrov, D.S.

    2008-01-01

    We consider collisional properties of weakly bound heteronuclear molecules (dimers) formed in a two-species mixture of atoms with a large mass difference. We focus on dimers containing light fermionic atoms as they manifest collisional stability due to an effective dimer-dimer repulsion originating

  5. Infrared spectroscopy of weakly bound molecular ions

    Energy Technology Data Exchange (ETDEWEB)

    Yeh, Lisa I-Ching

    1988-11-01

    The infrared spectra of a series of hydrated hydronium cluster ions and of protonated ethane ion are presented. A tandem mass spectrometer is ideally suited to obtaining the spectra of such weakly bound molecular ions. Traditional absorption spectroscopy is not feasible in these situations, so the techniques described in this thesis make use of some consequence of photon absorption with higher sensitivity than simply attenuation of laser power. That consequence is dissociation. By first mass selecting the parent ion under study and then mass selecting the fragment ion formed from dissociation, the near unit detection efficiency of ion counting methods has been used to full advantage.

  6. Weakly bound states of two- and three-boson systems in the crossover from two to three dimensions

    DEFF Research Database (Denmark)

    Yamashita, Marcelo; Bellotti, Filipe Furlan; Frederico, Tobias

    2015-01-01

    The spectrum and properties of quantum bound states is strongly dependent on the dimensionality of space. How this comes about and how one may theoretically and experimentally study the interpolation between different dimensions is a topic of great interest in different fields of physics. In this...

  7. Prediction of a weakly bound excited state of Efimov character in a 7LiHe42 system

    Science.gov (United States)

    Wu, Meng-Shan; Han, Hui-Li; Li, Cheng-Bin; Shi, Ting-Yun

    2014-12-01

    We carry out calculations on the van der Waals trimer 7LiHe42 using the mapping method within the frame of hyperspherical coordinates, which allows us to give accurate binding energies and wave functions for both the ground and excited state of the system. When the realistic two-body potentials are adopted, the system presents an excited state which shows Efimov character. We study the range of the interaction strength in which the excited state could exist and find that the state persists within the experiment error band for binding energy of LiHe molecule. We also study the three-body parameter (3BP) of 7LiHe42 system and its relationship with the background scattering length aHeHe. Our calculations demonstrate that the 3BP of 7LiHe42 system is dependent on the value of the scattering length aHeHe, independent of the short-range details of the He-He interaction. The results confirm the prediction of Wang et al. [Phys. Rev. Lett. 109, 243201 (2012), 10.1103/PhysRevLett.109.243201] that the 3BP for a heteronuclear atomic system is universally determined from the van der Waals lengths and the homonuclear scattering length.

  8. Weakly bound states with spin-isospin symmetry

    Science.gov (United States)

    Kievsky, A.; Gattobigio, M.

    2016-03-01

    We discuss weakly bound states of a few-fermion system having spin-isospin symmetry. This corresponds to the nuclear physics case in which the singlet, a0, and triplet, a1, n - p scattering lengths are large with respect to the range of the nuclear interaction. The ratio of the two is about a0/a1 ≈ -4.31. This value defines a plane in which a0 and a1 can be varied up to the unitary limit, 1/a0 = 0 and 1/a1 = 0, maintaining its ratio fixed. Using a spin dependant potential model we estimate the three-nucleon binding energy along that plane. This analysis can be considered an extension of the Efimov plot for three bosons to the case of three 1/2-spin-isospin fermions.

  9. Weakly bound states with spin-isospin symmetry

    CERN Document Server

    Kievsky, A

    2015-01-01

    We discuss weakly bound states of a few-fermion system having spin-isospin symmetry. This corresponds to the nuclear physics case in which the singlet, $a_0$, and triplet, $a_1$, $n-p$ scattering lengths are large with respect to the range of the nuclear interaction. The ratio of the two is about $a_0/a_1\\approx-4.31$. This value defines a plane in which $a_0$ and $a_1$ can be varied up to the unitary limit, $1/a_0=0$ and $1/a_1=0$, maintaining its ratio fixed. Using a spin dependant potential model we estimate the three-nucleon binding energy along that plane. This analysis can be considered an extension of the Efimov plot for three bosons to the case of three $1/2$-spin-isospin fermions.

  10. Weakly bound states with spin-isospin symmetry

    Directory of Open Access Journals (Sweden)

    Kievsky A.

    2016-01-01

    Full Text Available We discuss weakly bound states of a few-fermion system having spin-isospin symmetry. This corresponds to the nuclear physics case in which the singlet, a0, and triplet, a1, n − p scattering lengths are large with respect to the range of the nuclear interaction. The ratio of the two is about a0/a1 ≈ −4.31. This value defines a plane in which a0 and a1 can be varied up to the unitary limit, 1/a0 = 0 and 1/a1 = 0, maintaining its ratio fixed. Using a spin dependant potential model we estimate the three-nucleon binding energy along that plane. This analysis can be considered an extension of the Efimov plot for three bosons to the case of three 1/2-spin-isospin fermions.

  11. Continuum discretized BCS approach for weakly bound nuclei

    CERN Document Server

    Lay, J A; Fortunato, L; Vitturi, A

    2015-01-01

    The Bardeen-Cooper-Schrieffer (BCS) formalism is extended by including the single-particle continuum, thus enabling the analysis of an isotopic chain from stability up to the drip line. We propose a continuum discretized generalized BCS based on single-particle pseudostates (PS). These PS are generated from the diagonalization of the single-particle Hamiltonian within a Transformed Harmonic Oscillator (THO) basis. The consistency of the results versus the size of the basis is studied. The method is applied to neutron rich Oxygen and Carbon isotopes and compared with similar previous works and available experimental data. We make use of the flexibility of the proposed model in order to study the evolution of the occupation of the low-energy continuum when the system becomes weakly bound. We find a larger influence of the non-resonant continuum as long as the Fermi level approaches zero.

  12. Electron Capture Dissociation of Weakly Bound Polypeptide Polycationic Complexes

    DEFF Research Database (Denmark)

    Haselmann, Kim F; Jørgensen, Thomas J D; Budnik, Bogdan A;

    2002-01-01

    We have previously reported that, in electron capture dissociation (ECD), rupture of strong intramolecular bonds in weakly bound supramolecular aggregates can proceed without dissociation of weak intermolecular bonds. This is now illustrated on a series of non-specific peptide-peptide dimers...... as well as specific complexes of modified glycopeptide antibiotics with their target peptide. The weak nature of bonding is substantiated by blackbody infrared dissociation, low-energy collisional excitation and force-field simulations. The results are consistent with a non-ergodic ECD cleavage mechanism....

  13. Continuum Coupling and Pair Correlation in Weakly Bound Deformed Nuclei

    CERN Document Server

    Oba, Hiroshi

    2009-01-01

    We formulate a new Hartree-Fock-Bogoliubov method applicable to weakly bound deformed nuclei using the coordinate-space Green's function technique. An emphasis is put on treatment of quasiparticle states in the continuum, on which we impose the correct boundary condition of the asymptotic out-going wave. We illustrate this method with numerical examples.

  14. Characterization and reactivity of the weakly bound complexes of the [H, N, S]{sup −} anionic system with astrophysical and biological implications

    Energy Technology Data Exchange (ETDEWEB)

    Trabelsi, T.; Ajili, Y.; Ben Yaghlane, S.; Jaidane, N.-E. [Laboratoire de Spectroscopie Atomique, Moléculaire et Applications–LSAMA, Université de Tunis El Manar, Tunis (Tunisia); Mogren Al-Mogren, M. [Chemistry Department, Faculty of Science, King Saud University, P.O. Box 2455, Riyadh 11451 (Saudi Arabia); Francisco, J. S. [Department of Chemistry and Department of Earth and Atmospheric Sciences, Purdue University, West Lafayette, Indiana 47906 (United States); Hochlaf, M., E-mail: hochlaf@univ-mlv.fr [Laboratoire Modélisation et Simulation Multi Echelle, Université Paris-Est, MSME UMR 8208 CNRS, 5 Blvd. Descartes, 77454 Marne-la-Vallée (France)

    2015-07-21

    We investigate the lowest electronic states of doublet and quartet spin multiplicity states of HNS{sup −} and HSN{sup −} together with their parent neutral triatomic molecules. Computations were performed using highly accurate ab initio methods with a large basis set. One-dimensional cuts of the full-dimensional potential energy surfaces (PESs) along the interatomic distances and bending angle are presented for each isomer. Results show that the ground anionic states are stable with respect to the electron detachment process and that the long range parts of the PESs correlating to the SH{sup −} + N, SN{sup −} + H, SN + H{sup −}, NH + S{sup −}, and NH{sup −} + S are bound. In addition, we predict the existence of long-lived weakly bound anionic complexes that can be formed after cold collisions between SN{sup −} and H or SH{sup −} and N. The implications for the reactivity of these species are discussed; specifically, it is shown that the reactions involving SH{sup −}, SN{sup −}, and NH{sup −} lead either to the formation of HNS{sup −} or HSN{sup −} in their electronic ground states or to autodetachment processes. Thus, providing an explanation for why the anions, SH{sup −}, SN{sup −}, and NH{sup −}, have limiting detectability in astrophysical media despite the observation of their corresponding neutral species. In a biological context, we suggest that HSN{sup −} and HNS{sup −} should be incorporated into H{sub 2}S-assisted heme-catalyzed reduction mechanism of nitrites in vivo.

  15. Bounding approaches to system identification

    CERN Document Server

    Norton, John; Piet-Lahanier, Hélène; Walter, Éric

    1996-01-01

    In response to the growing interest in bounding error approaches, the editors of this volume offer the first collection of papers to describe advances in techniques and applications of bounding of the parameters, or state variables, of uncertain dynamical systems. Contributors explore the application of the bounding approach as an alternative to the probabilistic analysis of such systems, relating its importance to robust control-system design.

  16. [Systemic lupus erythematosus and weakness].

    Science.gov (United States)

    Vinagre, Filipe; Santos, Maria José; da Silva, José Canas

    2006-01-01

    We report a case of a 13-year old young girl, with Juvenile Systemic Lupus Erythematosus and recent onset of muscle weakness. Investigations lead to the diagnosis of Myasthenia Gravis. The most important causes of muscle weakness in lupus patients are discussed.

  17. Recent Results on Fusion and Direct Reactions with Weakly Bound Stable Nuclei

    Directory of Open Access Journals (Sweden)

    Shrivastava A.

    2011-10-01

    Full Text Available Recent measurements of fusion and direct reactions in case of weakly bound stable nuclei at extreme sub-barrier energies using a sensitive off beam technique are presented. Deviation in slope of the fusion excitation function, as observed in case of medium heavy systems, is absent in the present asymmetric systems at these low energies. These results along with the study of capture reaction of the breakup fragments using particle- gamma coincidences is presented, thereby giving the current status of the field.

  18. Role of nuclear couplings in the inelastic excitation of weakly-bound neutron-rich nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Dasso, C.H. [Niels Bohr Institute, Copenhagen (Denmark); Lenzi, S.M.; Vitturi, A. [Universita di Padova (Italy)

    1996-12-31

    Much effort is presently devoted to the study of nuclear systems far from the stability line. Particular emphasis has been placed in light systems such as {sup 11}Li, {sup 8}B and others, where the very small binding energy of the last particles causes their density distribution to extend considerably outside of the remaining nuclear core. Some of the properties associated with this feature are expected to characterize also heavier systems in the vicinity of the proton or neutron drip lines. It is by now well established that low-lying concentrations of multipole strength arise from pure configurations in which a peculiar matching between the wavelength of the continuum wavefunction of the particles and the range of the weakly-bound hole states occurs. To this end the authors consider the break-up of a weakly-bound system in a heavy-ion collision and focus attention in the inelastic excitation of the low-lying part of the continuum. They make use of the fact that previous investigations have shown that the multipole response in this region is not of a collective nature and describe their excited states as pure particle-hole configurations. Since the relevant parameter determining the strength distributions is the binding energy of the last bound orbital they find it most convenient to use single-particle wavefunctions generated by a sperical square-well potential with characteristic nuclear dimensions and whose depth has been adjusted to give rise to a situation in which the last occupied neutron orbital is loosely-bound. Spin-orbit couplings are, for the present purpose, ignored. The results of this investigation clearly indicate that nuclear couplings have the predominant role in causing projectile dissociation in many circumstances, even at bombarding energies remarkably below the Coulomb barrier.

  19. Breakup Effect of Weakly Bound Projectile on the Barrier Distribution Around Coulomb Barrier

    Institute of Scientific and Technical Information of China (English)

    贾会明; 林承键; 张焕乔; 刘祖华; 喻宁; 杨峰; 徐新星; 贾飞; 吴振东; 张世涛

    2012-01-01

    The excitation function of quasi-elastic (QEL) scattering at a backward angle has been measured for 9^Be+208^Pb. The barrier distribution was extracted by means of the first derivative of the measured excitation function and calculated with the coupled-channel model. The present work shows that the experimental barrier distribution extracted from QEL scattering is shifted to the low energy side by 1.5 MeV as compared with the theoretical one. This energy discrepancy indicates that breakup is important in the colliding processes of the weakly bound nucleus system.

  20. Far-Infrared Spectroscopy of Weakly Bound Hydrated Cluster Molecules

    DEFF Research Database (Denmark)

    Andersen, Jonas

    -sized molecular clusters with water by means of far-infrared and terahertz neon matrix isolation spectroscopy. The embedding of non-covalent cluster molecules in solid cryogenic neon matrices at 2.8 K ensures a high sensitivity for direct spectroscopic observations of the large-amplitude intermolecular...... vibrational bands of the cluster molecules in the challenging far-infrared and terahertz spectral regions.A key parameter in the validation of the performance of theoretical predictions for weak non-covalent intermolecular interactions is the dissociation energy D0 that depends heavily on the class of large...

  1. Bounds on the Capacity of Weakly constrained two-dimensional Codes

    DEFF Research Database (Denmark)

    Forchhammer, Søren

    2002-01-01

    Upper and lower bounds are presented for the capacity of weakly constrained two-dimensional codes. The maximum entropy is calculated for two simple models of 2-D codes constraining the probability of neighboring 1s as an example. For given models of the coded data, upper and lower bounds...

  2. Weakly and strongly associated nonfreezable water bound in bones.

    Science.gov (United States)

    Turov, V V; Gun'ko, V M; Zarko, V I; Leboda, R; Jablonski, M; Gorzelak, M; Jagiello-Wojtowicz, E

    2006-03-15

    Water bound in bone of rat tail vertebrae was investigated by 1H NMR spectroscopy at 210-300 K and by the thermally stimulated depolarization current (TSDC) method at 190-265 K. The 1H NMR spectra of water clusters were calculated by the GIAO method with the B3LYP/6-31G(d,p) basis set, and the solvent effects were analyzed by the HF/SM5.45/6-31G(d) method. The 1H NMR spectra of water in bone tissue include two signals that can be assigned to typical water (chemical shift of proton resonance deltaH=4-5 ppm) and unusual water (deltaH=1.2-1.7 ppm). According to the quantum chemical calculations, the latter can be attributed to water molecules without the hydrogen bonds through the hydrogen atoms, e.g., interacting with hydrophobic environment. An increase in the amount of water in bone leads to an increase in the amount of typical water, which is characterized by higher associativity (i.e., a larger average number of hydrogen bonds per molecule) and fills larger pores, cavities and pockets in bone tissue.

  3. Classical simulations of heavy-ion fusion reactions and weakly-bound projectile breakup reactions

    Indian Academy of Sciences (India)

    S S Godre

    2014-05-01

    Heavy-ion collision simulations in various classical models are discussed. Heavy-ion reactions with spherical and deformed nuclei are simulated in a classical rigid-body dynamics (CRBD) model which takes into account the reorientation of the deformed projectile. It is found that the barrier parameters depend not only on the initial orientations of the deformed nucleus, but also on the collision energy and the moment of inertia of the deformed nucleus. Maximum reorientation effect occurs at near- and below-barrier energies for light deformed nuclei. Calculated fusion crosssections for 24Mg + 208Pb reaction are compared with a static-barrier-penetration model (SBPM) calculation to see the effect of reorientation. Heavy-ion reactions are also simulated in a 3-stage classical molecular dynamics (3S-CMD) model in which the rigid-body constraints are relaxed when the two nuclei are close to the barrier thus, taking into account all the rotational and vibrational degrees of freedom in the same calculation. This model is extended to simulate heavy-ion reactions such as 6Li + 209Bi involving the weakly-bound projectile considered as a weakly-bound cluster of deuteron and 4He nuclei, thus, simulating a 3-body system in 3S-CMD model. All the essential features of breakup reactions, such as complete fusion, incomplete fusion, no-capture breakup and scattering are demonstrated.

  4. Interplay of projectile breakup and target excitation in reactions induced by weakly bound nuclei

    Science.gov (United States)

    Gómez-Ramos, M.; Moro, A. M.

    2017-03-01

    Background: Reactions involving weakly bound nuclei require formalisms able to deal with continuum states. The majority of these formalisms struggle to treat collective excitations of the systems involved. For continuum-discretized coupled channels (CDCC), extensions to include target excitation have been developed but have only been applied to a small number of cases. Purpose: In this work, we reexamine the extension of the CDCC formalism to include target excitation and apply it to a variety of reactions to study the effect of breakup on inelastic cross sections. Methods: We use a transformed oscillator basis to discretize the continuum of the projectiles in the different reactions and use the extended CDCC method developed in this work to solve the resulting coupled differential equations. A new code has been developed to perform the calculations. Results: Reactions 58Ni(d ,d )*58Ni , 24Mg(d ,d )*24Mg , 144Sm(6Li,6Li)*144Sm , and 9Be(6Li,6Li)*9Be are studied. Satisfactory agreement is found between experimental data and extended CDCC calculations. Conclusions: The studied CDCC method has proven to be an accurate tool to describe target excitation in reactions with weakly bound nuclei. Moderate effects of breakup on inelastic observables are found for the reactions studied. Cross-section magnitudes are not modified much, but angular distributions present smoothing when opposed to calculations without breakup.

  5. Study of Exotic Weakly Bound Nuclei Using Magnetic Analyzer Mavr

    Science.gov (United States)

    Maslov, V. A.; Kazacha, V. I.; Kolesov, I. V.; Lukyanov, S. M.; Melnikov, V. N.; Osipov, N. F.; Penionzhkevich, Yu. E.; Skobelev, N. K.; Sobolev, Yu. G.; Voskoboinik, E. I.

    2016-06-01

    A project of the high-resolution magnetic analyzer MAVR is proposed. The analyzer will comprise new magnetic optical and detecting systems for separation and identification of reaction products in a wide range of masses (5-150) and charges (1-60). The magnetic optical system consists of the MSP-144 magnet and a doublet of quadrupole lenses. This will allow the solid angle of the spectrometer to be increased by an order of magnitude up to 30 msr. The magnetic analyzer will have a high momentum resolution (10-4) and high focal-plane dispersion (1.9 m). It will allow products of nuclear reactions at energies up to 30 MeV/nucleon to be detected with the charge resolution ∼1/60. Implementation of the project is divided into two stages: conversion of the magnetic analyzer proper and construction of the nuclear reaction products identification system. The MULTI detecting system is being developed for the MAVR magnetic analyzer to allow detection of nuclear reaction products and their identification by charge Q, atomic number Z, and mass A with a high absolute accuracy. The identification will be performed by measuring the energy loss (ΔE), time of flight (TOF), and total kinetic energy (TKE) of reaction products. The particle trajectories in the analyzer will also be determined using the drift chamber developed jointly with GANIL. The MAVR analyzer will operate in both primary beams of heavy ions and beams of radioactive nuclei produced by the U400 - U400M acceleration complex. It will also be used for measuring energy spectra of nuclear reaction products and as an energy monochromator.

  6. Structure Effects in Collisions Induced by Halo and Weakly Bound Nuclei Around the Coulomb Barrier

    CERN Document Server

    Scuderi, V; Torresi, D; Fisichella, M; Borge, M J G; Randisi, G; Milin, M; Figuera, P; Raabe, R; Di Pietro, A; Amorini, F; Fraile, L M; Vidal, A M; Rizzo, F; Zadro, M; Gomez-Camacho, J; Pellegriti, M G; Papa, M; Jeppesen, H; Santonocito, D; Sanchez, E M R; Acosta, L; Tengblad, O; Lattuada, M; Musumarra, A; Scalia, G

    2010-01-01

    In this contribution, results concerning different reaction channels for the collisions induced by the three Be isotopes, Be-9,Be-10,Be-11, on a Zn-64 target at energies around the Coulomb barrier will be presented. The experiments with the radioactive Be-10,Be-11 beams were performed at REX-ISOLDE (CERN) whereas the experiment with the stable weakly bound Be-9 beam was performed at LNS Catania. Elastic scattering angular distributions have been measured for the three systems Be-9,Be-10,Be-11 + Zn-64 at the same center of mass energy. The angular distributions were analyzed with optical potentials and reaction cross sections were obtained from optical model calculations, performed with the code PTOLEMY. For the Be-11 + Zn-64 reaction, the break-up angular distribution was also measured.

  7. Weak Precompactness in the Space of Vector-Valued Measures of Bounded Variation

    Directory of Open Access Journals (Sweden)

    Ioana Ghenciu

    2015-01-01

    Full Text Available For a Banach space X and a measure space (Ω,Σ, let M(Ω,X be the space of all X-valued countably additive measures on (Ω,Σ of bounded variation, with the total variation norm. In this paper we give a characterization of weakly precompact subsets of M(Ω,X.

  8. Weakly regular fluid flows with bounded variation on a Schwarzschild background

    CERN Document Server

    LeFloch, Philippe G

    2015-01-01

    We study the global dynamics of isothermal fluids evolving in the domain of outer communication of a Schwarzschild black hole. We first formulate the initial value problem within a class of weak solutions with bounded variation (BV), possibly containing shock waves. We then introduce a version of the random choice method and establish a global-in-time existence theory for the initial value problem within the proposed class of weakly regular fluid flows. The initial data may have arbitrary large bounded variation and can possibly blow up near the horizon of the black hole. Furthermore, we study the class of possibly discontinuous, equilibrium solutions and design a version of the random choice method in which these fluid equilibria are exactly preserved. This leads us to a nonlinear stability property for fluid equilibria under small perturbations with bounded variation. Furthermore, we can also encompass several limiting regimes (stiff matter, non-relativistic flows, extremal black hole) by letting the physic...

  9. Endurance bounds of aerial systems

    Science.gov (United States)

    Harrington, Aaron M.; Kroninger, Christopher M.

    2014-06-01

    Within the past few years micro aerial vehicles (MAVs) have received much more attention and are starting to proliferate into military as well as civilian roles. However, one of the major drawbacks for this technology currently, has been their poor endurance, usually below 10 minutes. This is a direct result of the inefficiencies inherent in their design. Often times, designers do not consider the various components in the vehicle design and match their performance to the desired mission for the vehicle. These vehicles lack a prescribed set of design guidelines or empirically derived design equations which often limits their design to selection of commercial off-the-shelf components without proper consideration of their affect on vehicle performance. In the current study, the design space for different vehicle configurations has been examined including insect flapping, avian flapping, rotary wing, and fixed wing, and their performance bounds are established. The propulsion system typical of a rotary wing vehicle is analyzed to establish current baselines for efficiency of vehicles at this scale. The power draw from communications is analyzed to determine its impact on vehicle performance. Finally, a representative fixed wing MAV is examined and the effects of adaptive structures as a means for increasing vehicle endurance and range are examined. This paper seeks to establish the performance bounds for micro air vehicles and establish a path forward for future designs so that efficiency may be maximized.

  10. Exotic Behaviour of Angular Dispersion of Weakly Bound Nucleus 17F at Small Angles

    Institute of Scientific and Technical Information of China (English)

    WANG Qi; YUAN Xiao-Hua; XU Zhi-Guo; ZHAO Tie-Cheng; ZHANG Hong-Bin; XU Hua-Gen; QI Hui-Rong; WANG Yue; JIA Fei; WU Li-Jie; DING Xian-Li; HAN Jian-Long; GAO Qi; GAO Hui; LI Song-Lin; BAI Zhen; XIAO Guo-Qing; JIN Gen-Ming; REN Zhong-Zhou; ZHOU Shan-Gui; SERGEY Yu-Kun; XIAO Zhi-Gang; XU Hu-Shan; SUN Zhi-Yu; HU Zheng-Guo; ZHANG Xue-Ying; WANG Hong-Wei; MAO Rui-Shi

    2006-01-01

    @@ The differential cross sections of 17 F and 17 O elastic scattering products on 208Pb have been measured at the Radioactive Ion Beam Line at Lanzhou (RIBLL). Two angular dispersion plots ofln( dσ/ dθ ) versus θ2 are obtained from the angular distribution of the elastic scattering differential cross sections. The angular dispersion plot exhibits a clear turning point for 17F in the range of small scattering angles 6°-20° due to its exotic structure,but for 17 O, the turning point is not observed in the same angular range. The experimental results have been compared with previous data of other groups. Systematical analysis on the available data supports the above conclusion that there is an exotic behaviour of the angular dispersion plot of weakly bound nuclei with halo or skin structure as compared with that of the ordinary nuclei near stable line. Therefore the turning point of the angular dispersion plot appears at small angle for weakly bound nuclei with halo or skin structure, and can be used as a new probe to investigate the halo and skin phenomena of weakly bound nuclei.

  11. Approaching the Cramer-Rao Bound in Weak Lensing with PDF Symmetrization

    CERN Document Server

    Zhang, Jun

    2016-01-01

    Weak lensing statistics is typically measured as weighted sum of shear estimators or their products (shear-shear correlation). The weighting schemes are designed in the hope of minimizing the statistical error without introducing systematic errors. It would be ideal to approach the Cramer-Rao bound (the lower bound of the statistical uncertainty) in shear statistics, though it is generally difficult to do so in practice. The reasons may include: difficulties in galaxy shape measurement, inaccurate knowledge of the probability-distribution-function (PDF) of the shear estimator, misidentification of point sources as galaxies, etc.. Using the shear estimators defined in Zhang et al. (2015), we show that one can overcome all these problems, and allow shear measurement accuracy to approach the Cramer-Rao bound. This can be achieved by symmetrizing the PDF of the shear estimator, or the joint PDF of shear estimator pairs (for shear-shear correlation), without any prior knowledge of the PDF. Using simulated galaxy i...

  12. Short-lived two-soliton bound states in weakly perturbed nonlinear Schrodinger equation.

    Science.gov (United States)

    Dmitriev, Sergey V.; Shigenari, Takeshi

    2002-06-01

    Resonant soliton collisions in the weakly discrete nonlinear Schrodinger equation are studied numerically. The fractal nature of the soliton scattering, described in our previous works, is investigated in detail. We demonstrate that the fractal scattering pattern is related to the existence of the short-lived two-soliton bound states. The bound state can be regarded as a two-soliton quasiparticle of a new type, different from the breather. We establish that the probability P of a bound state with the lifetime L follows the law P approximately L(-3). In the frame of a simple two-particle model, we derive the nonlinear map, which generates the fractal pattern similar to that observed in the numerical study of soliton collisions. (c) 2002 American Institute of Physics.

  13. The weak psuedoscalar coupling of the free and the bound protons

    Energy Technology Data Exchange (ETDEWEB)

    Gorringe, T.P. [Univ. of Kentucky, Lexington, KY (United States)

    1995-10-01

    The proton`s weak pseudoscalar coupling, g{sub p} is induced by the effects of its strong interaction on its weak interaction. In the Partially Conserved Axial Current hypothesis g{sub p} is due to single pion exchange between the leptonic and nucleonic currents in semi-leptonic weak processes. It predicts g{sub p} = 8.4 {plus_minus} 0.2 for the free proton but modifications of g{sub p}for the bound proton, due to modifications of the pion field of the bound proton, are possible. We will review the available data on g{sub p} for both the free and the bound proton. In the case of the free proton g{sub p} has been determined from measurements of ordinary (OMC) and radiative muon capture (RMC) on hydrogen. We will discuss the extraction of g{sub p} from the data, the importance of various {mu}-atomic and molecular processes in extracting g{sub p }and compare the results obtained from the OMC and RMC data and experiments in gaseous and liquid H{sub 2}. In the case of the bound proton we will discuss the measurements of ordinary and radiative {mu}{sup -} capture on complex nuclei and the extraction of g{sub p} from these data. The comparison of inclusive RMC and OMC rates on nuclei has led to speculations of a large enhancement of g{sub p} in light nuclei and a large quenching of g{sub p} in heavy nuclei. We will discuss the evidence for and against the renormalization, of g{sub p}in nuclei and the problems of extracting g{sub p} from the nuclear RMC and OMC data.

  14. A Weak Comparison Principle for Reaction-Diffusion Systems

    Directory of Open Access Journals (Sweden)

    José Valero

    2012-01-01

    Full Text Available We prove a weak comparison principle for a reaction-diffusion system without uniqueness of solutions. We apply the abstract results to the Lotka-Volterra system with diffusion, a generalized logistic equation, and to a model of fractional-order chemical autocatalysis with decay. Moreover, in the case of the Lotka-Volterra system a weak maximum principle is given, and a suitable estimate in the space of essentially bounded functions L∞ is proved for at least one solution of the problem.

  15. A weak comparison principle for reaction-diffusion systems

    CERN Document Server

    Valero, José

    2012-01-01

    In this paper we prove a weak comparison principle for a reaction-diffusion system without uniqueness of solutions. We apply the abstract results to the Lotka-Volterra system with diffusion, a generalized logistic equation and to a model of fractional-order chemical autocatalysis with decay. Morever, in the case of the Lotka-Volterra system a weak maximum principle is given, and a suitable estimate in the space of essentially bounded functions $L^{\\infty}$ is proved for at least one solution of the problem.

  16. A weakly monotonic backward induction algorithm on finite bounded subsets of vector lattices

    Science.gov (United States)

    Dragut, A. B.

    2004-03-01

    We present a new efficient and robust backward induction algorithm, which is weakly monotonic, working on bounded subsets without holes of lattices. We prove all its properties, give examples of applications, and illustrate its behavior, comparing it with the natural extension of the unidimensional algorithm presented in Puterman (Markov Decision Processes: Discrete Stochastic Dynamic Programming, Wiley, New York, 1994), in the sense of Topkis (Frontiers of Economic Research Series, Princeton University Press, Princeton, NJ, 1998) and White (Recent Developments in Markov Decision Processes, Academic Press, New York, 1980, 261) and showing, also experimentally, that it is much more efficient.

  17. Control of Optical Transitions with Magnetic Fields in Weakly Bound Molecules

    CERN Document Server

    McGuyer, B H; Iwata, G Z; Skomorowski, W; Moszynski, R; Zelevinsky, T

    2015-01-01

    Forbidden optical transitions in weakly bound $^{88}$Sr$_2$ molecules become strongly enabled with moderate applied magnetic fields. We report the control of transition strengths by five orders of magnitude and measurements of highly nonlinear Zeeman shifts, which we explain with an accurate {\\it ab initio} model. Mixed quantization in an optical lattice enables the experimental procedure. Our observation of formerly inaccessible $f$-parity excited states offers a new avenue for improving theoretical models for divalent atom dimers. Furthermore, magnetically enabled transitions may lead to an extremely precise subradiant molecular lattice clock.

  18. Weak Markov Processes as Linear Systems

    CERN Document Server

    Gohm, Rolf

    2012-01-01

    A noncommutative Fornasini-Marchesini system (a multi-variable version of a linear system) can be realized within a weak Markov process (a model for quantum evolution). For a discrete time parameter this is worked out systematically as a theory of representations of structure maps of a system by a weak process. We introduce subprocesses and quotient processes which can be described naturally by a suitable category of weak processes. A corresponding notion of cascade for processes induces a represented cascade of systems. We study the control theoretic notion of observability which turns out to be particularly interesting in connection with a cascade structure. As an application we gain new insights into stationary Markov chains where observability for the system is closely related to asymptotic completeness in the scattering theory of the chain. This motivates a general definition of asymptotic completeness in the category of weak processes.

  19. Evolution of Surface Deformations of Weakly-Bound Nuclei in the Continuum

    CERN Document Server

    Pei, J C; Xu, F R

    2013-01-01

    We study weakly-bound deformed nuclei based on coordinate-space Skyrme Hartree-Fock-Bogoliubov approach , in which a large box is employed for treating the continuum and surface diffuseness. Approaching the limit of core-halo deformation decoupling, calculations found an exotic "egg"-like structure consisting of a spherical core plus a prolate halo in $^{38}$Ne, in which the resonant continuum plays an essential role. Generally the halo probability and the decoupling effect in heavy nuclei are reduced compared to light nuclei, due to denser level densities around Fermi surfaces. However, deformed halos in medium-mass nuclei are possible with sparse levels of negative parity, for example, in $^{110}$Ge. The surface deformations of pairing density distributions are also influenced by the decoupling effect and are sensitive to the effective pairing Hamiltonian.

  20. Holder continuity of bounded weak solutions to generalized parabolic p-Laplacian equations II: singular case

    Directory of Open Access Journals (Sweden)

    Sukjung Hwang

    2015-11-01

    Full Text Available Here we generalize quasilinear parabolic p-Laplacian type equations to obtain the prototype equation $$ u_t - \\hbox{div} \\Big(\\frac{g(|Du|}{|Du|} Du\\Big = 0, $$ where g is a nonnegative, increasing, and continuous function trapped in between two power functions $|Du|^{g_0 -1}$ and $|Du|^{g_1 -1}$ with $1bounded weak solution is locally Holder continuous with some degree of commonality between degenerate and singular types. By using geometric characters, our proof does not rely on any of alternatives which is based on the size of solutions.

  1. Heavy-ion fusion cross sections of weakly bound {sup 9}Be on {sup 27}Al, {sup 64}Zn and tightly bound {sup 16}O on {sup 64}Zn target using Coulomb and proximity potential

    Energy Technology Data Exchange (ETDEWEB)

    Santhosh, K.P., E-mail: drkpsanthosh@gmail.com; Bobby Jose, V.

    2014-02-15

    The total fusion cross sections for the fusion of weakly bound {sup 9}Be on {sup 27}Al and {sup 64}Zn targets at near and above the barrier have been calculated using one dimensional barrier penetration model, taking scattering potential as the sum of Coulomb and proximity potential and the calculated values are compared with experimental data. For the purpose of comparison of the fusion of weakly bound projectiles and strongly bound projectiles, the total fusion cross sections for the reaction of tightly bound nucleus {sup 16}O on {sup 64}Zn have also been computed using a similar procedure. The calculated values of total fusion cross sections in all cases are compared with coupled channel calculations using the code CCFULL. The computed cross sections using Coulomb and proximity potential explain the fusion reactions well in both cases of weakly bound and strongly bound projectiles. Reduced reaction cross sections for the systems {sup 9}Be+{sup 27}Al, {sup 9}Be+{sup 64}Zn and {sup 16}O+{sup 64}Zn have also been described.

  2. Heavy-ion fusion cross sections of weakly bound $^{9}$Be on $^{27}$Al, $^{64}$Zn and tightly bound $^{16}$O on $^{64}$Zn target using Coulomb and proximity potential

    CERN Document Server

    Santhosh, K P

    2013-01-01

    The total fusion cross sections for the fusion of weakly bound $^{9}$Be on $^{27}$Al and $^{64}$Zn targets at near and above the barrier have been calculated using one dimensional barrier penetration model, taking scattering potential as the sum of Coulomb and proximity potential and the calculated values are compared with experimental data. For the purpose of comparison of the fusion of weakly bound projectiles and strongly bound projectiles, the total fusion cross sections for the reaction of tightly bound nucleus $^{16}$O on $^{64}$Zn have also been computed using a similar procedure. The calculated values of total fusion cross sections in all cases are compared with coupled channel calculations using the code CCFULL. The computed cross sections using Coulomb and proximity potential explain the fusion reactions well in both cases of weakly bound and strongly bound projectiles. Reduced reaction cross sections for the systems $^{9}$Be + $^{27}$Al, $^{9}$Be+ $^{64}$Zn and $^{16}$O + $^{64}$Zn have also been d...

  3. Weakly Nonlinear Geometric Optics for Hyperbolic Systems of Conservation Laws

    CERN Document Server

    Chen, Gui-Qiang; Zhang, Yongqian

    2012-01-01

    We establish an $L^1$-estimate to validate the weakly nonlinear geometric optics for entropy solutions of nonlinear hyperbolic systems of conservation laws with arbitrary initial data of small bounded variation. This implies that the simpler geometric optics expansion function can be employed to study the properties of general entropy solutions to hyperbolic systems of conservation laws. Our analysis involves new techniques which rely on the structure of the approximate equations, besides the properties of the wave-front tracking algorithm and the standard semigroup estimates.

  4. Universality of weakly bound dimers and Efimov trimers close to Li-Cs Feshbach resonances

    Science.gov (United States)

    Ulmanis, J.; Häfner, S.; Pires, R.; Kuhnle, E. D.; Weidemüller, M.; Tiemann, E.

    2015-05-01

    We study the interspecies scattering properties of ultracold Li-Cs mixtures in their two energetically lowest spin channels in the magnetic field range between 800 and 1000 G. Close to two broad Feshbach resonances (FR) we create weakly bound LiCs dimers by radio-frequency association and measure the dependence of their binding energy on the external magnetic field strength. Based on the binding energies and complementary atom loss spectroscopy of three other Li-Cs s-wave FRs we construct precise molecular singlet and triplet electronic ground state potentials using a coupled-channels calculation. We extract the Li-Cs interspecies scattering length as a function of the external field and obtain almost a ten-fold improvement in the precision of the values for the pole positions and widths of the s-wave FRs as compared to our previous work (Pires et al 2014 Phys. Rev. Lett. 112 250404). We discuss implications on the Efimov scenario and the universal geometric scaling for LiCsCs trimers.

  5. Interplay of projectile breakup and target excitation in reactions induced by weakly-bound nuclei

    CERN Document Server

    Gomez-Ramos, M

    2016-01-01

    In this work, we reexamine the extension of the CDCC formalism to include target excitation and apply it to a variety of reactions to study the effect of breakup on inelastic cross sections. We use a transformed oscillator basis to discretize the continuum of the projectiles in the different reactions and use the extended CDCC method developed in this work to solve the resulting coupled differential equations. A new code has been developed to perform the calculations. Reactions 58Ni(d, d) 58Ni*, 24Mg(d, d) 24Mg* , 144Sm( 6Li, 6Li) 144Sm* and 9Be( 6Li, 6Li) 9Be* are studied. Satisfactory agreement is found between experimental data and extended CDCC calculations. The studied CDCC method is proved to be an accurate tool to describe target excitation in reactions with weakly-bound nuclei. Moderate effects of breakup on inelastic observables are found for the reactions studied. Cross section magnitudes are not modified much, but angular distributions present smoothing when opposed to calculations without breakup.

  6. Hyperaccretion during Tidal Disruption Events: Weakly Bound Debris Envelopes and Jets

    Science.gov (United States)

    Coughlin, Eric R.; Begelman, Mitchell C.

    2014-02-01

    After the destruction of the star during a tidal disruption event (TDE), the cataclysmic encounter between a star and the supermassive black hole (SMBH) of a galaxy, approximately half of the original stellar debris falls back onto the hole at a rate that can initially exceed the Eddington limit by orders of magnitude. We argue that the angular momentum of this matter is too low to allow it to attain a disk-like configuration with accretion proceeding at a mildly super-Eddington rate, the excess energy being carried away by a combination of radiative losses and radially distributed winds. Instead, we propose that the infalling gas traps accretion energy until it inflates into a weakly bound, quasi-spherical structure with gas extending nearly to the poles. We study the structure and evolution of such "zero-Bernoulli accretion" flows as a model for the super-Eddington phase of TDEs. We argue that such flows cannot stop extremely super-Eddington accretion from occurring, and that once the envelope is maximally inflated, any excess accretion energy escapes through the poles in the form of powerful jets. We compare the predictions of our model to Swift J1644+57, the putative super-Eddington TDE, and show that it can qualitatively reproduce some of its observed features. Similar models, including self-gravity, could be applicable to gamma-ray bursts from collapsars and the growth of SMBH seeds inside quasi-stars.

  7. Hyperaccretion during tidal disruption events: weakly bound debris envelopes and jets

    CERN Document Server

    Coughlin, Eric R

    2013-01-01

    After the destruction of the star during a tidal disruption event (TDE), the cataclysmic encounter between a star and the supermassive black hole (SMBH) of a galaxy, approximately half of the original stellar debris falls back onto the hole at a rate that can initially exceed the Eddington limit by orders of magnitude. We argue that the angular momentum of this matter is too low to allow it to attain a disk-like configuration with accretion proceeding at a mildly super-Eddington rate, the excess energy being carried away by a combination of radiative losses and radially distributed winds. Instead, we propose that the infalling gas traps accretion energy until it inflates into a weakly-bound, quasi-spherical structure with gas extending nearly to the poles. We study the structure and evolution of such "Zero-Bernoulli accretion" flows (ZEBRAs) as a model for the super-Eddington phase of TDEs. We argue that such flows cannot stop extremely super-Eddington accretion from occurring, and that once the envelope is m...

  8. Photodissociation dynamics of weakly bound He H2 + in intense light fields

    Science.gov (United States)

    Szidarovszky, Tamás; Yamanouchi, Kaoru

    2016-12-01

    Photoinduced dynamics of a weakly bound triatomic molecule He H2 + exposed to electromagnetic radiation is investigated by time-dependent quantum wave-packet propagation. Adopting a two-dimensional linear H-H-He model, the three lowest-lying potential energy surfaces (PESs) and corresponding dipole moment surfaces are constructed. One of the two characteristic excited PESs of He H2 + leads to the charge-transfer reaction H2 ++He → H2+H e+ and the other corresponds to the first excited state of H2 + perturbed by the presence of He. When He H2 + is exposed to a femtosecond intense ultraviolet light pulse (I =4 ×1014W c m-2 , λ =400 nm ), both of the two excited PESs are found to be coupled with the light field and a variety of reaction pathways become opened so that HeH, He H+ , H2, H2 +,H , H+ , He, and H e+ are produced. Simulations also show that the anharmonic coupling between the two stretching vibrational modes in He H2 + leads to the stabilization of the H2 + moiety against the decomposition into H + H+ compared with bare H2 +. The theoretical findings of the formation of He H+ composed of the most abundant elements in the universe are also discussed in view of the theoretical modeling of the chemical reactions proceeding in the primordial gas and in the interstellar medium.

  9. Nonuniversality of weak synchronization in chaotic systems

    OpenAIRE

    Vieira, M. de Sousa; Lichtenberg, A.J.

    1997-01-01

    We show that the separate properties of weak synchronization (WS) and strong synchronization (SS), reported recently by Pyragas [K. Pyragas, Phys. Rev. E, 54, R4508 (1996)], in unidirectionally coupled chaotic systems, are not generally distinct properties of such systems. In particular, we find analytically for the tent map and numerically for some parameters of the circle map that the transition to WS and SS coincide.

  10. On the existence of weak solutions to the three-dimensional steady compressible Navier-Stokes equations in bounded domains

    CERN Document Server

    Jiang, Song

    2011-01-01

    We prove the existence of a weak solution to the three-dimensional steady compressible isentropic Navier-Stokes equations in bounded domains for any specific heat ratio \\gamma > 1. Generally speaking, the proof is based on the new weighted estimates of both pressure and kinetic energy for the approximate system which result in some higher integrability of the density, and the method of weak convergence. Comparing with [12] where the spatially periodic case was studied, here we have to control the additional integral terms of both pressure and kinetic energy involving with the points near the boundary which become degenerate when the points approach the boundary. Such integral terms are estimated using some new techniques, i.e., we use the techniques of the mirror image and boundary straightening to prove that the weighted estimates of both pressure and kinetic energy for the points near the boundary can be controlled by the weighted estimates for the points on the boundary. Moreover, we prove that once the we...

  11. Infrared Spectrum of CO-O2, a 'new' Weakly-Bound Complex

    Science.gov (United States)

    McKellar, Bob; Barclay, A. J.; Michaelian, K. H.; Moazzen-Ahmadi, Nasser

    2016-06-01

    Only a few weakly-bound complexes containing the O2 molecule have been characterized by high-resolution spectroscopy, notably N2O-O2 [1] and HF-O2 [2]. This neglect is no doubt due in part to the complications added by the oxygen unpaired electron spin. Here we report an extensive infrared spectrum of CO-O2, as observed in the CO fundamental band region (˜2150 wn) using a tunable quantum cascade laser to probe a pulsed supersonic jet expansion. The derived energy level pattern consists of 'stacks' characterized by K, the projection of the total angular momentum on the intermolecular axis. Five such stacks are observed in the ground vibrational state, and ten in the excited state, v(CO) = 1. They are divided into two groups, with no observed transitions between groups, and we believe these groups correlate with the two lowest rotational states of O2, namely (N, J) = (1, 0) and (1, 2). In many ways, the spectrum and energy levels are similar to those of CO-N2 [3], and we use the same approach for analysis, simply fitting each stack with its own origin, B-value, and distortion constants. The rotational constant of the lowest stack in the ground state (with K = 0) implies an effective intermolecular separation of 3.82 Å, but this should be interpreted with caution since it ignores possible effects of electron spin. [1] H.-B. Qian, D. Seccombe, and B.J. Howard, J. Chem. Phys. 107, 7658 (1997). [2] W.M. Fawzy, C.M. Lovejoy, D.J. Nesbitt, and J.T. Hougen, J. Chem. Phys. 117, 693 (2002); S. Wu, G. Sedo, E.M. Grumstrup, and K.R. Leopold, J. Chem. Phys. 127, 204315 (2007). [3] M. Rezaei, K.H. Michaelian, N. Moazzen-Ahmadi, and A.R.W. McKellar, J. Phys. Chem. A 117, 13752 (2013), and references therein.

  12. Invariance and stability for bounded uncertain systems.

    Science.gov (United States)

    Peng, T. K. C.

    1972-01-01

    The positive limit sets of the solutions of a contingent differential equation are shown to possess an invariance property. In this connection the 'invariance principle' in the theory of Lyapunov stability is extended to systems with unknown, bounded, time-varying parameters, and thus to a large and important class of nonautonomous systems. Asymptotic stability criteria are obtained and applied to guaranteed cost control problems.

  13. Dynamics of fragment capture for cluster structures of weakly bound 7Li

    Directory of Open Access Journals (Sweden)

    Shrivastava A.

    2013-12-01

    Full Text Available Role of cluster structures of 7Li on reaction dynamics have been studied by performing exclusive measurements of prompt-γ rays from residues with scattered particles at energy, E/Vb = 1.6, with 198Pt target. Yields of the residues resulting after capture of t and 4,5,6He, corresponding to different excitation energies of the composite system were estimated. The results were compared with three body classical-dynamical model for breakup fusion, constrained by the measured fusion, α and t capture cross-sections. The cross-section of residues from capture of α and t agreed well with the prediction of the model showing dominance of the two step process - breakup fusion, while those from tightly bound 6He showed massive transfer to be the dominant mechanism.

  14. Relative entropies, suitable weak solutions, and weak strong uniqueness for the compressible Navier-Stokes system

    CERN Document Server

    Feireisl, Eduard; Novotny, Antonin

    2011-01-01

    We introduce the notion of relative entropy for the weak solutions of the compressible Navier-Stokes system. We show that any finite energy weak solution satisfies a relative entropy inequality for any pair of sufficiently smooth test functions. As a corollary we establish weak-strong uniqueness principle for the compressible Navier-Stokes system.

  15. Bound states of Dipolar Bosons in One-dimensional Systems

    DEFF Research Database (Denmark)

    G. Volosniev, A.; R. Armstrong, J.; V. Fedorov, D.;

    2013-01-01

    -body structures in this geometry are determined as function of polarization angles and dipole strength by using both essentially exact stochastic variational methods and the harmonic approximation. The main focus is on the three, four, and five-body problems in two or more tubes. Our results indicate...... that in the weakly-coupled limit the inter-tube interaction is similar to a zero-range term with a suitable rescaled strength. This allows us to address the corresponding many-body physics of the system by constructing a model where bound chains with one molecule in each tube are the effective degrees of freedom...

  16. Chirality of weakly bound complexes: The potential energy surfaces for the hydrogen-peroxide−noble-gas interactions

    Energy Technology Data Exchange (ETDEWEB)

    Roncaratti, L. F., E-mail: lz@fis.unb.br; Leal, L. A.; Silva, G. M. de [Instituto de Física, Universidade de Brasília, 70910 Brasília (Brazil); Pirani, F. [Dipartimento di Chimica, Biologia e Biotecnologie, Università di Perugia, 06123 Perugia (Italy); Aquilanti, V. [Dipartimento di Chimica, Biologia e Biotecnologie, Università di Perugia, 06123 Perugia (Italy); Instituto de Física, Universidade Federal da Bahia, 40210 Salvador (Brazil); Gargano, R. [Instituto de Física, Universidade de Brasília, 70910 Brasília (Brazil); Departments of Chemistry and Physics, University of Florida, Quantum Theory Project, Gainesville, Florida 32611 (United States)

    2014-10-07

    We consider the analytical representation of the potential energy surfaces of relevance for the intermolecular dynamics of weakly bound complexes of chiral molecules. In this paper we study the H{sub 2}O{sub 2}−Ng (Ng=He, Ne, Ar, Kr, and Xe) systems providing the radial and the angular dependence of the potential energy surface on the relative position of the Ng atom. We accomplish this by introducing an analytical representation which is able to fit the ab initio energies of these complexes in a wide range of geometries. Our analysis sheds light on the role that the enantiomeric forms and the symmetry of the H{sub 2}O{sub 2} molecule play on the resulting barriers and equilibrium geometries. The proposed theoretical framework is useful to study the dynamics of the H{sub 2}O{sub 2} molecule, or other systems involving O–O and S–S bonds, interacting by non-covalent forces with atoms or molecules and to understand how the relative orientation of the O–H bonds changes along collisional events that may lead to a hydrogen bond formation or even to selectivity in chemical reactions.

  17. Visualizing weakly bound surface Fermi arcs and their correspondence to bulk Weyl fermions.

    Science.gov (United States)

    Batabyal, Rajib; Morali, Noam; Avraham, Nurit; Sun, Yan; Schmidt, Marcus; Felser, Claudia; Stern, Ady; Yan, Binghai; Beidenkopf, Haim

    2016-08-01

    Fermi arcs are the surface manifestation of the topological nature of Weyl semimetals, enforced by the bulk-boundary correspondence with the bulk Weyl nodes. The surface of tantalum arsenide, similar to that of other members of the Weyl semimetal class, hosts nontopological bands that obscure the exploration of this correspondence. We use the spatial structure of the Fermi arc wave function, probed by scanning tunneling microscopy, as a spectroscopic tool to distinguish and characterize the surface Fermi arc bands. We find that, as opposed to nontopological states, the Fermi arc wave function is weakly affected by the surface potential: it spreads rather uniformly within the unit cell and penetrates deeper into the bulk. Fermi arcs reside predominantly on tantalum sites, from which the topological bulk bands are derived. Furthermore, we identify a correspondence between the Fermi arc dispersion and the energy and momentum of the bulk Weyl nodes that classify this material as topological. We obtain these results by introducing an analysis based on the role the Bloch wave function has in shaping quantum electronic interference patterns. It thus carries broader applicability to the study of other electronic systems and other physical processes.

  18. Landauer Bound for Analog Computing Systems

    CERN Document Server

    Diamantini, M Cristina; Trugenberger, Carlo A

    2016-01-01

    By establishing a relation between information erasure and continuous phase transitions we generalise the Landauer bound to analog computing systems. The entropy production per degree of freedom during erasure of an analog variable (reset to standard value) is given by the logarithm of the configurational volume measured in units of its minimal quantum. As a consequence every computation has to be carried on with a finite number of bits and infinite precision is forbidden by the fundamental laws of physics, since it would require an infinite amount of energy.

  19. Landauer bound for analog computing systems

    Science.gov (United States)

    Diamantini, M. Cristina; Gammaitoni, Luca; Trugenberger, Carlo A.

    2016-07-01

    By establishing a relation between information erasure and continuous phase transitions we generalize the Landauer bound to analog computing systems. The entropy production per degree of freedom during erasure of an analog variable (reset to standard value) is given by the logarithm of the configurational volume measured in units of its minimal quantum. As a consequence, every computation has to be carried on with a finite number of bits and infinite precision is forbidden by the fundamental laws of physics, since it would require an infinite amount of energy.

  20. Weak Solution to a Parabolic Nonlinear System Arising in Biological Dynamic in the Soil

    Directory of Open Access Journals (Sweden)

    Côme Goudjo

    2011-01-01

    Full Text Available We study a nonlinear parabolic system governing the biological dynamic in the soil. We prove global existence (in time and uniqueness of weak and positive solution for this reaction-diffusion semilinear system in a bounded domain, completed with homogeneous Neumann boundary conditions and positive initial conditions.

  1. Weak KAM theory for a weakly coupled system of Hamilton–Jacobi equations

    KAUST Repository

    Figalli, Alessio

    2016-06-23

    Here, we extend the weak KAM and Aubry–Mather theories to optimal switching problems. We consider three issues: the analysis of the calculus of variations problem, the study of a generalized weak KAM theorem for solutions of weakly coupled systems of Hamilton–Jacobi equations, and the long-time behavior of time-dependent systems. We prove the existence and regularity of action minimizers, obtain necessary conditions for minimality, extend Fathi’s weak KAM theorem, and describe the asymptotic limit of the generalized Lax–Oleinik semigroup. © 2016, Springer-Verlag Berlin Heidelberg.

  2. Suppressing the weakly bound states in the photoassociation dynamics by using a frequency cut-off laser pulse

    Institute of Scientific and Technical Information of China (English)

    Lin Feng; Zhang Wei; Zhao Ze-Yu; Cong Shu-Lin

    2012-01-01

    The photoassociation dynamics of ultracold lithium atoms controlled by a cut-off pulse has been investigated theoretically by solving numerically the time-dependent Schr(o)dinger equation using the mapped Fourier grid method.The frequency components of the laser pulse close to the atomic resonance are partly cut off.Compared with the typical Gauss-type pulses,the cut-off pulse is helpful to suppress efficiently the weakly bound states and prepare the associated molecules in the lower vibrational states.Especially,the dependence of photoassociation probability on the cut-off position of the laser pulse is explored.

  3. On the energy conservation by weak solutions of the relativistic Vlasov-Maxwell system

    OpenAIRE

    Sospedra-Alfonso, Reinel

    2010-01-01

    We show that weak solutions of the relativistic Vlasov-Maxwell system preserve the total energy provided that the electromagnetic field is locally of bounded variation and, for any $\\lambda$> 0, the one-particle distribution function has a square integrable $\\lambda$-moment in the momentum variable.

  4. BV weak solutions to Gauss-Codazzi system for isometric immersions

    Science.gov (United States)

    Christoforou, Cleopatra

    The isometric immersion problem for surfaces embedded into R is studied via the fluid dynamic framework introduced in Chen et al. (2010) [6] as a system of balance laws of mixed-type. The techniques developed in the theory of weak solutions of bounded variation in continuum physics are employed to deal with the isometric immersions in the setting of differential geometry. The so-called BV framework is formed that establishes convergence of approximate solutions of bounded variation to the Gauss-Codazzi system and yields the C isometric realization of two-dimensional surfaces into R. Local and global existence results are established for weak solutions of small bounded variation to the Gauss-Codazzi system for negatively curved surfaces that admit equilibrium configurations. As an application, the case of catenoidal shell of revolution is provided.

  5. Positive blowup solutions for some fractional systems in bounded domains

    Directory of Open Access Journals (Sweden)

    Ramzi Alsaedi

    2013-01-01

    Full Text Available Using some potential theory tools and the Schauder fixed point theorem, we prove the existence of a positive continuous weak solution for the fractional system $$ ( -Delta ^{alpha/2}u+ p(xu^{sigma }v^{r}=0,quad (-Delta^{alpha/2}v+q(xu^{s}v^{eta }=0 $$ in a bounded $ C^{1,1}$-domain D in $mathbb{R}^{n}$ $(ngeq 3$, subject to Dirichlet conditions, where $0

  6. Importance of lifetime effects in breakup and suppression of complete fusion in reactions of weakly bound nuclei

    CERN Document Server

    Cook, K J; Luong, D H; Kalkal, Sunil; Dasgupta, M; Hinde, D J

    2016-01-01

    Complete fusion cross sections in collisions of light, weakly bound nuclei and high Z targets show above-barrier suppression of complete fusion. This has been interpreted as resulting from breakup of the weakly bound nucleus prior to reaching the fusion barrier, reducing the probability of complete fusion. This paper investigates how these conclusions are affected by lifetimes of the resonant states that are populated prior to breakup. If the mean life of a populated resonance is much longer than the fusion timescale, then its breakup cannot suppress complete fusion. For short-lived resonances, the situation is more complex. This work includes the mean life of the short-lived 2+ resonance in 8Be in classical dynamical model calculations to determine its effect on energy and angular correlations of the breakup fragments and on predictions of fusion suppression. Coincidence measurements of breakup fragments produced in reactions of 9Be with 144Sm, 168Er, 186W, 196Pt, 208Pb and 209Bi at energies below the barrie...

  7. Weakly Bound Free Radicals in Combustion: "Prompt" Dissociation of Formyl Radicals and Its Effect on Laminar Flame Speeds

    Energy Technology Data Exchange (ETDEWEB)

    Labbe, Nicole J.; Sivaramakrishnan, Raghu; Goldsmith, C. Franklin; Georgievskii, Yuri; Miller, James A.; Klippenstein, Stephen J.

    2016-01-07

    Weakly bound free radicals have low-dissociation thresholds such that at high temperatures, timescales for dissociation and collisional relaxation become comparable, leading to significant dissociation during the vibrational-rotational relaxation process. Here we characterize this “prompt” dissociation of formyl (HCO), an important combustion radical, using direct dynamics calculations for OH + CH2O and H + CH2O (key HCO-forming reactions). For all other HCO-forming reactions, presumption of a thermal incipient HCO distribution was used to derive prompt dissociation fractions. Inclusion of these theoretically derived HCO prompt dissociation fractions into combustion kinetics models provides an additional source for H-atoms that feeds chain branching reactions. Simulations using these updated combustion models are therefore shown to enhance flame propagation in 1,3,5-trioxane and acetylene. The present results suggest that HCO prompt dissociation should be included when simulating flames of hydrocarbons and oxygenated molecules and that prompt dissociations of other weakly bound radicals may also impact combustion simulations

  8. Weakly Bound Free Radicals in Combustion: "Prompt" Dissociation of Formyl Radicals and Its Effect on Laminar Flame Speeds.

    Science.gov (United States)

    Labbe, Nicole J; Sivaramakrishnan, Raghu; Goldsmith, C Franklin; Georgievskii, Yuri; Miller, James A; Klippenstein, Stephen J

    2016-01-01

    Weakly bound free radicals have low-dissociation thresholds such that at high temperatures, time scales for dissociation and collisional relaxation become comparable, leading to significant dissociation during the vibrational-rotational relaxation process. Here we characterize this "prompt" dissociation of formyl (HCO), an important combustion radical, using direct dynamics calculations for OH + CH2O and H + CH2O (key HCO-forming reactions). For all other HCO-forming reactions, presumption of a thermal incipient HCO distribution was used to derive prompt dissociation fractions. Inclusion of these theoretically derived HCO prompt dissociation fractions into combustion kinetics models provides an additional source for H-atoms that feeds chain-branching reactions. Simulations using these updated combustion models are therefore shown to enhance flame propagation in 1,3,5-trioxane and acetylene. The present results suggest that HCO prompt dissociation should be included when simulating flames of hydrocarbons and oxygenated molecules and that prompt dissociations of other weakly bound radicals may also impact combustion simulations.

  9. Quantum Defect Theory description of weakly bound levels and Feshbach resonances in LiRb

    CERN Document Server

    Pérez-Ríos, Jesús; Chen, Yong P; Greene, Chris H

    2014-01-01

    The multichannel quantum defect theory (MQDT) in combination with the frame transformation (FT) approach is applied to model the Fano-Feshbach resonances measured for $^{7}$Li$^{87}$Rb and $^{6}$Li$^{87}$Rb [Marzok {\\it et al.} Phys. Rev. A {\\bf 79} 012717 (2009)]. The MQDT results show a level of accuracy comparable to that of previous models based on direct, fully numerical solutions of the the coupled channel Schr\\"odinger equations (CC). Here, energy levels deduced from 2-photon photoassociation spectra for $^{7}$Li$^{85}$Rb are assigned by applying the MQDT approach, obtaining the bound state energies for the coupled channel problem. Our results confirm that MQDT yields a compact description of photoassociation observables as well as the Fano-Feshbach resonance positions and widths.

  10. Interaction of weakly bound antibiotics neomycin and lincomycin with bovine and human serum albumin: biophysical approach.

    Science.gov (United States)

    Keswani, Neelam; Choudhary, Sinjan; Kishore, Nand

    2010-07-01

    The thermodynamics of interaction of neomycin and lincomycin with bovine serum albumin (BSA) and human serum albumin (HSA) has been studied using isothermal titration calorimetry (ITC), in combination with UV-visible, steady state and time resolved fluorescence spectroscopic measurements. Neomycin is observed to bind weakly to BSA and HSA whereas lincomycin did not show any evidence for binding with the native state of these proteins, rather it interacts in the presence of surfactants. The ITC results suggest 1 : 1 binding stoichiometry for neomycin in the studied temperature range. The values of the van't Hoff enthalpy do not agree with the calorimetric enthalpy in the case of neomycin, suggesting conformational changes in the protein upon ligand binding, as well as with the rise in the temperature. Experiments at different ionic strengths, and in the presence of tetrabutyl ammonium bromide and surfactants suggest the predominant involvement of electrostatic interactions in the complexation process of neomycin with BSA and HSA, and non-specific interaction behaviour of lincomycin with these proteins.

  11. Direct and indirect effects of dispersion interactions on the electric properties of weakly bound complexes.

    Science.gov (United States)

    Medveď, Miroslav; Budzák, Šimon; Laurent, Adèle D; Jacquemin, Denis

    2015-03-26

    Direct (electronic) and indirect (geometrical) modifications of the molecular properties of weakly interacting complexes between the push-pull p-aminobenzoic acid (pABA) molecule and the nonpolar benzene (Bz) have been studied with a large panel of wave function (WF) and density functional theory (DFT) based methods using carefully selected atomic basis sets. For pABA, both the canonical (pABA-c) and zwitterionic (pABA-z) forms have been investigated. Owing to strongly distinct charge distributions, the two forms of pABA enable us to mimic different interaction modes with Bz. In this work, we assessed the performances of dispersion-corrected DFT methods, as well as of long-range corrected exchange-correlation functionals. It follows from the SAPT analysis that both the structure and the interaction energy of the first complex (pABA-c···Bz) is mainly controlled by dispersion interactions whereas, in the second complex (pABA-z···Bz), electrostatic and induction forces play also an important role. Our results suggest that the (non)linear electric properties of push-pull and zwitterionic molecules can be significantly reduced by the presence of a nonpolar compound. We also show that even for a complex with stability strongly determined by dispersion forces, the direct dispersion contributions to its electric properties can be small. Nevertheless, the intersystem distance is influenced by dispersion forces, which, in turn indirectly tune the induced properties. The zwitterionic derivative appears to be more challenging in the context of molecular properties.

  12. Investigations of the potential functions of weakly bound diatomic molecules and laser-assisted excitive Penning ionization

    Energy Technology Data Exchange (ETDEWEB)

    Goble, J.H. Jr.

    1982-05-01

    Three variations on the Dunham series expansion function of the potential of a diatomic molecule are compared. The differences among these expansions lie in the choice of the expansion variable, lambda. The functional form of these variables are lambda/sub s/ = l-r/sub e//r for the Simon-Parr-Finlan version, lambda/sub T/ - 1-(r/sub e//r)/sup p/ for that of Thakkar, and lambda/sub H/ = 1-exp(-rho(r/r/sub e/-1) for that of Huffaker. A wide selection of molecular systems are examined. It is found that, for potentials in excess of thirty kcal/mole, the Huffaker expansion provides the best description of the three, extrapolating at large internuclear separation to a value within 10% of the true dissociation energy. For potentials that result from the interaction of excited states, all series expansions show poor behavior away from the equilibrium internuclear separation of the molecule. The series representation of the potentials of weakly bound molecules are examined in more detail. The ground states of BeAr/sup +/, HeNe/sup +/, NaAr, and Ar/sub 2/ and the excited states of HeNe+, NaNe, and NaAr are best described by the Thakkar expansion. Finally, the observation of laser-assisted excitive Penning ionization in a flowing afterglow is reported. The reaction Ar(/sup 3/P/sub 2/) + Ca + h nu ..-->.. Ar + Ca/sup +/(5p /sup 2/P/sub J/) + e/sup -/ occurs when the photon energy, h nu, is approximately equal to the energy difference between the metastable argon and one of the fine structure levels of the ion's doublet. By monitoring the cascade fluorescence of the above reaction and comparing it to the flourescence from the field-free process Ar(/sup 3/P/sub 2/) + Ca ..-->.. Ar + Ca/sup +/(4p /sup 2/P/sub J/) + e/sup -/ a surprisingly large cross section of 6.7 x 10/sup 3/ A/sup 2/ is estimated.

  13. Evidence for a dynamically refracted primary bow in weakly bound $^9$Be rainbow scattering from $^{16}$O

    CERN Document Server

    Ohkubo, S

    2016-01-01

    We present for the first time evidence for the existence of a dynamically refracted primary bow for $^{9}$Be+$^{16}$O scattering. This is demonstrated through the use of coupled channel calculations with an extended double folding potential derived from the density-dependent effective two-body force and precise microscopic cluster wave functions for $^{9}$Be. The calculations reproduce the experimental Airy structure in $^{9}$Be+$^{16}$O scattering well.It is found that coupling of a weakly bound $^{9}$Be nucleus to excited states plays the role of a booster lens, dynamically enhancing the refraction over the {\\it static} refraction due to the Luneburg lens mean field potential between the ground states of $^{9}$Be and $^{16}$O.

  14. Weakly linear systems of fuzzy relation inequalities: The heterogeneous case

    CERN Document Server

    Ignjatović, Jelena; Damljanović, Nada; Jančić, Ivana

    2011-01-01

    New types of systems of fuzzy relation inequalities and equations, called weakly linear, have been recently introduced in [J. Ignjatovi\\'c, M. \\'Ciri\\'c, S. Bogdanovi\\'c, On the greatest solutions to weakly linear systems of fuzzy relation inequalities and equations, Fuzzy Sets and Systems 161 (2010) 3081--3113.]. The mentioned paper dealt with homogeneous weakly linear systems, composed of fuzzy relations on a single set, and a method for computing their greatest solutions has been provided. This method is based on the computing of the greatest post-fixed point, contained in a given fuzzy relation, of an isotone function on the lattice of fuzzy relations. Here we adapt this method for computing the greatest solutions of heterogeneous weakly linear systems, where the unknown fuzzy relation relates two possibly different sets. We also introduce and study quotient fuzzy relational systems and establish relationships between solutions to heterogeneous and homogeneous weakly linear systems. Besides, we point out ...

  15. The weakly bound He-HCCCN complex: High-resolution microwave spectra and intermolecular potential-energy surface

    Science.gov (United States)

    Topic, Wendy C.; Jäger, Wolfgang

    2005-08-01

    Rotational spectra of the weakly bound He-HCCCN and He-DCCCN van der Waals complexes were observed using a pulsed-nozzle Fourier-transform microwave spectrometer in the 7-26-GHz frequency region. Nuclear quadrupole hyperfine structures due to the N14 and D nuclei (both with nuclear-spin quantum number I =1) were resolved and assigned. Both strong a and weaker b-type transitions were observed and the assigned transitions were used to fit the parameters of a distortable asymmetric rotor model. The dimers are floppy, near T-shaped complexes. Three intermolecular potential-energy surfaces were calculated using the coupled-cluster method with single and double excitations and noniterative inclusion of triple excitations. Bound-state rotational energy levels supported by these surfaces were determined. The quality of the potential-energy surfaces was assessed by comparing the experimental and calculated transition frequencies and also the corresponding spectroscopic parameters. Simple scaling of the surfaces improved both the transition frequencies and spectroscopic constants. Five other recently reported surfaces [O. Akin-Ojo, R. Bukowski, and K. Szalewicz, J. Chem. Phys. 119, 8379 (2003)], calculated using a variety of methods, and their agreement with spectroscopic properties of He-HCCCN are discussed.

  16. Bunched soliton states in weakly coupled sine-Gordon systems

    DEFF Research Database (Denmark)

    Grønbech-Jensen, N.; Samuelsen, Mogens Rugholm; Lomdahl, P. S.

    1990-01-01

    The interaction between solitons of two weakly coupled sine-Gordon systems is considered. In particular, the stability of bunched states is investigated, and perturbation results are compared with numerical results.......The interaction between solitons of two weakly coupled sine-Gordon systems is considered. In particular, the stability of bunched states is investigated, and perturbation results are compared with numerical results....

  17. A weak condition for secant method to solve systems of nonlinear equations

    Institute of Scientific and Technical Information of China (English)

    LIANG Ke-wei; HAN Dan-fu; ZHANG Hong; ZHU Cheng-yan

    2009-01-01

    In this paper, a new weak condition for the convergence of secant method to solve the systems of nonlinear equations is proposed. A convergence ball with the center x0 is replaced by that with X1, the first approximation generated by the secant method with the initial data x-1 and x0. Under the bounded conditions of the divided difference, a convergence theorem is obtained and two examples to illustrate the weakness of convergence conditions are provided.Moreover, the secant method is applied to a system of nonlinear equations to demonstrate the viability and effectiveness of the results in the paper.

  18. Continuity in weak topology: higher order linear systems of ODE

    Institute of Scientific and Technical Information of China (English)

    ZHANG MeiRong

    2008-01-01

    We will introduce a type of Fredholm operators which are shown to have a certain continuity in weak topologies. From this, we will prove that the fundamental matrix solutions of k-th,k≥ 2, order linear systems of ordinary differential equations are continuous in coefficient matrixes with weak topologies. Consequently, Floquet multipliers and Lyapunov exponents for periodic systems are continuous in weak topologies. Moreover, for the scalar Hill's equations, Sturm-Liouville eigenvalues,periodic and anti-periodic eigenvalues, and rotation numbers are all continuous in potentials with weak topologies. These results will lead to many interesting variational problems.

  19. Probing transfer to unbound states of the ejectile with weakly bound 7Li on 93Nb

    CERN Document Server

    Pandit, S K; Mahata, K; Keeley, N; Parkar, V V; Rout, P C; Martel, I; Palshetkar, C S; Kumar, A; Ramachandran, K; Patale, P; Chatterjee, A; Kailas, S

    2016-01-01

    The two-step process of transfer followed by breakup is explored by measuring a rather complete set of exclusive data for reaction channels populating states in the ejectile continua of the $^7$Li+$^{93}$Nb system at energies close to the Coulomb barrier. The cross sections for $\\alpha+\\alpha$ events from one proton pickup were found to be smaller than those for $\\alpha+d$ events from one neutron stripping and $\\alpha+t$ events from direct breakup of $^7$Li. Coupled channels Born approximation and continuum discretized coupled channels calculations describe the data well and support the conclusion that the $\\alpha+d$ and $\\alpha+\\alpha$ events are produced by direct transfer to unbound states of the ejectile.

  20. Algebraic structure and Poisson method for a weakly nonholonomic system

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The algebraic structure and the Poisson method for a weakly nonholonomic system are studied.The differential equations of motion of the system can be written in a contravariant algebra form and its algebraic structure is discussed.The Poisson theory for the systems which possess Lie algebra structure is generalized to the weakly nonholonomic system.An example is given to illustrate the application of the result.

  1. Search for a bound K− pp system

    Directory of Open Access Journals (Sweden)

    Camerini P.

    2010-04-01

    Full Text Available Data from the K− absorption reaction on 6,7Li, 9Be, 13C and 16O have recently been collected by FINUDA at the DAΦNE φ-factory (Laboratori Nazionali di Frascati-INFN, following an earlier lower statitics run on 12C and some other targets. FINUDA is a high acceptance magnetic spectrometer which performed a wide range of studies by detecting the charged particles and neutrons exiting the targets after the absorption event. In this paper it is discussed about the study of the A(K− , Λp reaction in the context of the search for deeply bound $ar{K}$ - nuclear states. The observation of a bump in the Λp invariant mass distribution is discussed in terms of a possible signature of a deeply bound K− pp kaonic cluster as well as of more conventional physics. An overview of the experimental situation in this field will be given.

  2. Weak and strong stabilization of linear systems

    Institute of Scientific and Technical Information of China (English)

    Mohamed OUZAHRA; Hamid BOURRAY; Asmae KAMAL; Rachid El AYADI

    2009-01-01

    We study the problem of stabilizing a distributed linear system on a subregion of its geometrical domain. We are concerned with two methods: the first approach enables us to characterize a stabilizing control via the steady state Riccati equation, and the second one is based on decomposing the state space into two suitable subspaces and studying the projections of the initial system onto such subspaces. The obtained results are performed through various examples.

  3. Breakup coupling effects on near-barrier inelastic scattering of the weakly bound {sup 6}Li projectile on a {sup 144}Sm target

    Energy Technology Data Exchange (ETDEWEB)

    Woodard, A.E., E-mail: awoodard@nd.edu [Laboratorio Tandar, Comision Nacional de Energia Atomica, B1650KNA San Martin, Buenos Aires (Argentina); Figueira, J.M. [Laboratorio Tandar, Comision Nacional de Energia Atomica, B1650KNA San Martin, Buenos Aires (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas, C1033AAJ Ciudad de Buenos Aires (Argentina); Otomar, D.R. [Instituto de Fisica, Universidade Federal Fluminense, Gragoata, Niteroi, R. J., 24210-340 (Brazil); Fernandez Niello, J.O. [Laboratorio Tandar, Comision Nacional de Energia Atomica, B1650KNA San Martin, Buenos Aires (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas, C1033AAJ Ciudad de Buenos Aires (Argentina); Escuela de Ciencia y Tecnologia, Universidad de San Martin, B1650BWA San Martin, Buenos Aires (Argentina); Lubian, J. [Instituto de Fisica, Universidade Federal Fluminense, Gragoata, Niteroi, R. J., 24210-340 (Brazil)

    2012-01-01

    Angular distributions for the inelastic scattering of the weakly bound {sup 6}Li nucleus from a {sup 144}Sm target (associated with the contributions of both the 2{sub 1}{sup +} and 3{sub 1}{sup -144}Sm excited states together) were measured at bombarding energies close to the Coulomb barrier. The experimental data were compared with expected results based on continuum discretized coupled-channel (CDCC) calculations. The results confirm that it is essential to include continuum-continuum couplings to reproduce the experimental data. The analysis demonstrates that inelastic scattering data can be a critical tool in testing full CDCC calculations involving weakly bound nuclei.

  4. Evidence for weakly bound electrons in non-irradiated alkane crystals. The electrons as a probe of structural differences in crystals

    CERN Document Server

    Pietrow, M; Misiak, L E; Kornarzynski, K; Szurkowski, J; Rochowski, P; Grzegorczyk, M

    2014-01-01

    It is generally assumed that weakly bound (trapped) electrons in organic solids come only from radiolytical (or photochemical) processes like ionization caused by an excited positron entering the sample. This paper presents an evidence for the presence of these electrons in non-irradiated samples of docosane. We argue that these electrons can be located (trapped) either in interlamellar gaps or in spaces made by non-planar conformers. The electrons from the former ones are bound more weakly than those from the latter ones. The origin of Vis absorption for the samples is explained. These spectra can be used as a probe indicating differences in the solid structures of hydrocarbons.

  5. Uniform and weak stability of Bresse system with two infinite memories

    Science.gov (United States)

    Guesmia, Aissa; Kirane, Mokhtar

    2016-10-01

    In this paper, we consider one-dimensional linear Bresse systems in a bounded open domain under Dirichlet-Neumann-Neumann boundary conditions with two infinite memories acting only on two equations. First, we establish the well-posedness in the sense of semigroup theory. Then, we prove two (uniform and weak) decay estimates depending on the speeds of wave propagations, the smoothness of initial data and the arbitrarily growth at infinity of the two relaxation functions.

  6. Bounded stabilisation of stochastic port-Hamiltonian systems

    Science.gov (United States)

    Satoh, Satoshi; Saeki, Masami

    2014-08-01

    This paper proposes a stochastic bounded stabilisation method for a class of stochastic port-Hamiltonian systems. Both full-actuated and underactuated mechanical systems in the presence of noise are considered in this class. The proposed method gives conditions for the controller gain and design parameters under which the state remains bounded in probability. The bounded region and achieving probability are both assignable, and a stochastic Lyapunov function is explicitly provided based on a Hamiltonian structure. Although many conventional stabilisation methods assume that the noise vanishes at the origin, the proposed method is applicable to systems under persistent disturbances.

  7. Consensus of Heterogeneous Multiagent Systems with Arbitrarily Bounded Communication Delay

    Directory of Open Access Journals (Sweden)

    Xue Li

    2017-01-01

    Full Text Available This paper focuses on the consensus problem of high-order heterogeneous multiagent systems with arbitrarily bounded communication delays. Through the method of nonnegative matrices, we get a sufficient consensus condition for the systems with dynamically changing topology. The results of this paper show, even when there are arbitrarily bounded communication delays in the systems, all agents can reach a consensus no matter whether there are spanning trees for the corresponding communication graphs at any time.

  8. On the Weak* Drop Property for Polar of Closed Bounded Convex Sets%关于有界闭凸集的极上的弱滴性

    Institute of Scientific and Technical Information of China (English)

    张子厚

    2004-01-01

    We define and study the weak* drop property for the polar of a closed bounded convex set in a Banach space which is both a generalization of the weak* drop property for dual norm in a Banach space and a characterization of the sub-differential mappingx→αp(x) from S(X) into 2S(X*) that is norm upper semi-countinuous and norm compact-valued.

  9. Weakly Bound Clusters in Astrochemistry? Millimeter and Submillimeter Spectroscopy of trans-HO3 and Comparison to Astronomical Observations.

    Science.gov (United States)

    Zou, Luyao; Hays, Brian M; Weaver, Susanna L Widicus

    2016-02-11

    The emergence of chemical complexity during star and planet formation is largely guided by the chemistry of unstable molecules that are reaction intermediates in terrestrial chemistry. Our knowledge of these intermediates is limited by both the lack of laboratory studies and the difficulty in their astronomical detection. In this work, we focus on the weakly bound cluster HO3 as an example of the connection between laboratory spectroscopic study and astronomical observations. Here, we present a fast-sweep spectroscopic technique in the millimeter and submillimeter range to facilitate the laboratory search for trans-HO3 and DO3 transitions in a discharge supersonic jet and report their rotational spectra from 70 to 450 GHz. These new measurements enable full determination of the molecular constants of HO3 and DO3. We also present a preliminary search for trans-HO3 in 32 star-forming regions using this new spectroscopic information. HO3 is not detected, and column density upper limits are reported. This work provides additional benchmark information for computational studies of this intriguing radical, as well as a reliable set of molecular constants for extrapolation of the transition frequencies of HO3 for future astronomical observations.

  10. Bunched soliton states in weakly coupled sine-Gordon systems

    Energy Technology Data Exchange (ETDEWEB)

    Gronbech-Jensen, N.; Samuelsen, M.R. (Physics Laboratory I, The Technical University of Denmark, DK-2800 Lyngby (Denmark)); Lomdahl, P.S. (Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM (USA)); Blackburn, J.A. (Department of Physics and Computing, Wilfrid Laurier University, Waterloo, Ontario (Canada))

    1990-09-01

    The interaction between solitons of two weakly coupled sine-Gordon systems is considered. In particular, the stability of bunched states is investigated, and perturbation results are compared with numerical results.

  11. ɛ-bounded state estimation for time-delay systems with bounded disturbances

    Science.gov (United States)

    Nam, P. T.; Pathirana, P. N.; Trinh, H.

    2014-09-01

    A new problem on ε-bounded functional state estimation for time-delay systems with unknown bounded disturbances is studied in this paper. In the presence of unknown bounded disturbances, the common assumption regarding the observer's matching condition is no longer required. In this regard, instead of achieving asymptotic convergence for the observer error, the error is now required to converge exponentially within a ball with a small radius ε > 0. This means that the estimate converges exponentially within an ε-bound of the true value. A general observer that utilises multiple-delayed output and input information is proposed. Sufficient conditions for the existence of the proposed observer are first given. We then employ an extended Lyapunov-Krasovskii functional which combines the delay-decomposition technique with a triple-integral term to study the ε-convergence problem of the observer error system. Moreover, the obtained results are shown to be more effective than the existing results for the cases with no disturbances and/or no time delay. Three numerical examples are given to illustrate the obtained results.

  12. Tetraquarks as diquark–antidiquark bound systems

    Directory of Open Access Journals (Sweden)

    M. Monemzadeh

    2015-02-01

    Full Text Available In this paper, we study four-body systems consisting of diquark–antidiquark, and we analyze diquark–antidiquark in the framework of a two-body (pseudo-point problem. We solve Lippman–Schwinger equation numerically for charm diquark–antidiquark systems and find the eigenvalues to calculate the binding energies and masses of heavy tetraquarks with hidden charms. Our results are in good agreement with theoretical and experimental data.

  13. Noise Separation from the Weak Signal Chaotic Detection System

    Directory of Open Access Journals (Sweden)

    Hanjie Gu

    2014-11-01

    Full Text Available The traditional weak signal chaotic detection system still restricts some technical issues in the situation of the signal with noise, such as poor denoising ability and low detection precision. In this paper, we propose a novel weak signal chaotic detection system based on an improved wavelet transform algorithm. First, the traditional wavelet transform algorithm domain variables have been transformed and discretized to eliminate the redundant transform. Then, based on the discrete optimization, the wavelet coefficients have been optimized by threshold compromise strategy. The improved wavelet transform algorithm is applied in the weak signal chaotic detection system. The noise signal after finite discrete processing is treated as a perturbation of cycle power and put into a chaotic system for detecting weak signal under the noise conditions. The simulation experiments show that the proposed improved wavelet transform algorithm has a better denoising effect than the traditional wavelet transform algorithm. Moreover, the improved algorithm shows better accuracy and higher robustness in the weak signal chaotic detection system.

  14. A Novel Weak Fuzzy Solution for Fuzzy Linear System

    Directory of Open Access Journals (Sweden)

    Soheil Salahshour

    2016-03-01

    Full Text Available This article proposes a novel weak fuzzy solution for the fuzzy linear system. As a matter of fact, we define the right-hand side column of the fuzzy linear system as a piecewise fuzzy function to overcome the related shortcoming, which exists in the previous findings. The strong point of this proposal is that the weak fuzzy solution is always a fuzzy number vector. Two complex and non-complex linear systems under uncertainty are tested to validate the effectiveness and correctness of the presented method.

  15. Work extraction from quantum systems with bounded fluctuations in work

    Science.gov (United States)

    Richens, Jonathan G.; Masanes, Lluis

    2016-11-01

    In the standard framework of thermodynamics, work is a random variable whose average is bounded by the change in free energy of the system. This average work is calculated without regard for the size of its fluctuations. Here we show that for some processes, such as reversible cooling, the fluctuations in work diverge. Realistic thermal machines may be unable to cope with arbitrarily large fluctuations. Hence, it is important to understand how thermodynamic efficiency rates are modified by bounding fluctuations. We quantify the work content and work of formation of arbitrary finite dimensional quantum states when the fluctuations in work are bounded by a given amount c. By varying c we interpolate between the standard and minimum free energies. We derive fundamental trade-offs between the magnitude of work and its fluctuations. As one application of these results, we derive the corrected Carnot efficiency of a qubit heat engine with bounded fluctuations.

  16. Bound systems in an expanding universe

    CERN Document Server

    Baker, G A

    2000-01-01

    The Schwarzchild solution insertion in an expanding universe, the so-called "Swiss cheese model," is shown to possess an extrinsic curvature miss-match. One consequence is that some trajectories are discontinuous functions of their initial conditions. An alternate metric is proposed which goes smoothly between the Schwarzchild exterior solution and the Friedmann-Lemaitre, expanding universe metric. It is further shown that the effects of the expansion on planetary motions in the solar system are too small to be currently observed for this alternate metric.

  17. Exact synchronization bound for coupled time-delay systems

    Science.gov (United States)

    Senthilkumar, D. V.; Pesquera, Luis; Banerjee, Santo; Ortín, Silvia; Kurths, J.

    2013-04-01

    We obtain an exact bound for synchronization in coupled time-delay systems using the generalized Halanay inequality for the general case of time-dependent delay, coupling, and coefficients. Furthermore, we show that the same analysis is applicable to both uni- and bidirectionally coupled time-delay systems with an appropriate evolution equation for their synchronization manifold, which can also be defined for different types of synchronization. The exact synchronization bound assures an exponential stabilization of the synchronization manifold which is crucial for applications. The analytical synchronization bound is independent of the nature of the modulation and can be applied to any time-delay system satisfying a Lipschitz condition. The analytical results are corroborated numerically using the Ikeda system.

  18. Upper bounds on the entropy of radiation systems

    Institute of Scientific and Technical Information of China (English)

    汪定雄

    1997-01-01

    The upper bounds on the entropy of a radiation system confined to a spherical box are calculated in six cases by using the equation of state of radiation in flat spacetime and the equation of state of radiation near black-hole horizon,which was derived by Li and Liu (hereafter the Li-Liu equation).It turns out that the Li-Liu equation does have unique advantage in dealing with the entropy bound of critical self-gravitating radiation systems,while the usual equation of state will result in entropy divergence.In the case of non-self-gravitating radiation systems and non-critical self-gravitating radiation systems,there is no difference in the entropy bounds derived by these two equations of state.

  19. Error bound results for convex inequality systems via conjugate duality

    CERN Document Server

    Bot, Radu Ioan

    2010-01-01

    The aim of this paper is to implement some new techniques, based on conjugate duality in convex optimization, for proving the existence of global error bounds for convex inequality systems. We deal first of all with systems described via one convex inequality and extend the achieved results, by making use of a celebrated scalarization function, to convex inequality systems expressed by means of a general vector function. We also propose a second approach for guaranteeing the existence of global error bounds of the latter, which meanwhile sharpens the classical result of Robinson.

  20. Optimal bounded control for maximizing reliability of Duhem hysteretic systems

    Institute of Scientific and Technical Information of China (English)

    Ming XU; Xiaoling JIN; Yong WANG; Zhilong HUANG

    2015-01-01

    The optimal bounded control of stochastic-excited systems with Duhem hysteretic components for maximizing system reliability is investigated. The Duhem hysteretic force is transformed to energy-depending damping and stiffness by the energy dissipation balance technique. The controlled system is transformed to the equivalent non-hysteretic system. Stochastic averaging is then implemented to obtain the Itˆo stochastic equation associated with the total energy of the vibrating system, appropriate for eval-uating system responses. Dynamical programming equations for maximizing system re-liability are formulated by the dynamical programming principle. The optimal bounded control is derived from the maximization condition in the dynamical programming equa-tion. Finally, the conditional reliability function and mean time of first-passage failure of the optimal Duhem systems are numerically solved from the Kolmogorov equations. The proposed procedure is illustrated with a representative example.

  1. Stability and response bounds of non-conservative linear systems

    DEFF Research Database (Denmark)

    Kliem, Wolfhard; Pommer, Christian

    2004-01-01

    This paper develops a stability theorem and response bounds for non-conservative systems of the form MX + (D + G)x + (K + N)x = f(t), with hermitian positive-definite matrices M, D and K, and skew-hermitian matrices G and N. To this end, we first find a Lyapunov function by solving the Lyapunov...... matrix equation. Then, if a system satisfies the condition of the stability theorem, the associated Lyapunov function can be used to obtain response bounds for the norms as well as for the individual coordinates of the solution. Examples from rotor dynamics illustrate the results....

  2. Linear operator inequalities for strongly stable weakly regular linear systems

    NARCIS (Netherlands)

    Curtain, RF

    2001-01-01

    We consider the question of the existence of solutions to certain linear operator inequalities (Lur'e equations) for strongly stable, weakly regular linear systems with generating operators A, B, C, 0. These operator inequalities are related to the spectral factorization of an associated Popov funct

  3. Evidence for weakly bound electrons in non-irradiated alkane crystals: The electrons as a probe of structural differences in crystals

    Energy Technology Data Exchange (ETDEWEB)

    Pietrow, M., E-mail: mrk@kft.umcs.lublin.pl; Misiak, L. E. [Institute of Physics, M. Curie-Skłodowska University, ul. Pl. M. Curie-Skłodowskiej 1, 20-031 Lublin (Poland); Gagoś, M. [Department of Cell Biology, Institute of Biology and Biochemistry, Maria Curie-Skłodowska University, ul. Akademicka 19, 20-033 Lublin (Poland); Kornarzyński, K. [Department of Physics, University of Life Sciences in Lublin, Akademicka 13, 20-950 Lublin (Poland); Szurkowski, J.; Grzegorczyk, M. [Institute of Experimental Physics, University of Gdańsk, Wita Stwosza 57, 80-952 Gdańsk (Poland); Rochowski, P. [Institute of Experimental Physics, University of Gdańsk, Wita Stwosza 57, 80-952 Gdańsk (Poland); Pomeranian University in Słupsk, Arciszewskiego 22b, 76-200 Słupsk (Poland)

    2015-02-14

    It is generally assumed that weakly bound (trapped) electrons in organic solids come only from radiolytical (or photochemical) processes like ionization caused by an excited positron entering the sample. This paper presents evidence for the presence of these electrons in non-irradiated samples of docosane. This can be due to the triboelectrification process. We argue that these electrons can be located (trapped) either in interlamellar gaps or in spaces made by non-planar conformers. Electrons from the former ones are bound more weakly than electrons from the latter ones. The origin of Vis absorption for the samples is explained. These spectra can be used as a probe indicating differences in the solid structures of hydrocarbons.

  4. Chaotic and Arnold stripes in weakly chaotic Hamiltonian systems.

    Science.gov (United States)

    Custódio, M S; Manchein, C; Beims, M W

    2012-06-01

    The dynamics in weakly chaotic Hamiltonian systems strongly depends on initial conditions (ICs) and little can be affirmed about generic behaviors. Using two distinct Hamiltonian systems, namely one particle in an open rectangular billiard and four particles globally coupled on a discrete lattice, we show that in these models, the transition from integrable motion to weak chaos emerges via chaotic stripes as the nonlinear parameter is increased. The stripes represent intervals of initial conditions which generate chaotic trajectories and increase with the nonlinear parameter of the system. In the billiard case, the initial conditions are the injection angles. For higher-dimensional systems and small nonlinearities, the chaotic stripes are the initial condition inside which Arnold diffusion occurs.

  5. Efficient Proof Engines for Bounded Model Checking of Hybrid Systems

    DEFF Research Database (Denmark)

    Fränzle, Martin; Herde, Christian

    2005-01-01

    In this paper we present HySat, a new bounded model checker for linear hybrid systems, incorporating a tight integration of a DPLL-based pseudo-Boolean SAT solver and a linear programming routine as core engine. In contrast to related tools like MathSAT, ICS, or CVC, our tool exploits all...

  6. Iterated Function Systems on Functions of Bounded Variation

    Science.gov (United States)

    La Torre, Davide; Mendivil, Franklin; Vrscay, Edward R.

    2016-04-01

    We show that under certain hypotheses, an iterated function system on mappings (IFSM) is a contraction on the complete space of functions of bounded variation (BV). It then possesses a unique attractor of BV. Some BV-based inverse problems based on the Collage Theorem for contraction maps are considered.

  7. The fate of bound systems through Sudden Future Singularities

    CERN Document Server

    Perivolaropoulos, Leandros

    2016-01-01

    Sudden singularities occur in FRW spacetimes when the scale factor remains finite and different from zero while some of its derivatives diverge. After proper rescaling, the scale factor close to such a singularity at $t=0$ takes the form $a(t)=1+ c |t|^\\eta$ (where $c$ and $\\eta$ are parameters and $\\eta\\geq 0$). We investigate analytically and numerically the geodesics of free and gravitationally bound particles through such sudden singularities. We find that even though free particle geodesics go through sudden singularities for all $\\eta\\geq 0$, bound systems get dissociated for a wide range of the parameter $c$. For $\\eta 1$ (Sudden Future Singularities (SFS)) bound systems get a finite impulse that depends on the value of $c$ and get dissociated for values of $c$ larger than a critical value $c_{cr}(\\eta,\\omega_0)>0$ that increases with the value of $\\eta$ and the rescaled angular velocity $\\omega_0$ of the bound system. We obtain an approximate equation for the analytical estimate of $c_{cr}(\\eta,\\omeg...

  8. Chaotic oscillator detection system about weak signals in spot welding

    Institute of Scientific and Technical Information of China (English)

    Kai-lei SONG; Zhen LUO; Feng YE; Xin-xin TANG; Shu-xian YUAN

    2009-01-01

    Spot welding is an efficient and shortcut processing method used in plate, and its quality detection is very important. However, there are many factors affecting the spot welding quality. Because of the low precision of traditional detection methods, spot welding has seldom been used in the aerospace industry which requires high welding quality. In this article, we give a new weak signal detection model based on chaotic oscillators. Using Melnikov methods and Lyapunov exponent, we can determine the critical values when the system enters in and out of chaos. Through lots of numerical simulations, it can be found that the lowest value of the weak sinusoidal signal the system can detect reach 10-11, and its signal-to-noise ratio (SNR) is = 126 dB. Compared with other detection methods, chaos oscillator detection system not only has a lower threshold value, but also is easy to implement in practice. This model thus has good application prospects.

  9. LOWER BOUNDS FOR FINITE WAVELET AND GABOR SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    Ole Christensen; Alexander M. Lindner

    2001-01-01

    Given ψ∈L2(R) and a finite sequence {(ar,λy)}τ∈r R+ XR consitiag of distinct points, the correspond wavelet system is the set of functions { )}τ∈r·We prove that for a dense set of functions ψ∈ ing L2(R) the wavelet system corresponding to any choice of {(aγ,λγ)}τ∈r is linearly independent, and we derive explicite estimates for the corresponding lower (frame) bounds. In particular, this puts restrictions on the choice of a scaling function in the theory for multiresolution analysis. We also obtain estimates for the lower bound for Gabor systems {e g(x-λr) }τ∈r for functions g in a dense subset of L2(R).

  10. Upper Capacity Bounds of MIMO Wireless Systems Through Fading Channels

    Directory of Open Access Journals (Sweden)

    Rachna Mahey

    2015-01-01

    Full Text Available This paper investigates the upper capacity bounds of MIMO systems with correlation and antenna selection techniques in general fading environments. With Antenna Selection techniques, the increased hardware complexity due to multiple antennas and large number of RF chains can be reduced to a substantial amount, retaining the diversity benefits of MIMO systems. The channel Correlation also affects the capacity of MIMO fading channels. Hence, to evaluate the upper bounds of capacity through fading channels, performance of MIMO systems is exemplified under Nakagami-m and Rayleigh fading channels while considering that the channel characteristics are known at a transmitter. The obtained results give an assessment to the better understanding to the effect of antenna selection and correlation on the capacity of MIMO channels, and how they can be used in different fading environments.

  11. The Malaysian Public Procurement's Prevalent System and its Weaknesses

    Directory of Open Access Journals (Sweden)

    Rohana Othman

    2010-01-01

    Full Text Available Problem statement: This study examined the public procurement system as prevalent in the Malaysian government system of administration. Various aspects of public procurement are outlined including types and the processes that entail public procurement. This study also highlighted the weaknesses in the manual public procurement processes that are opened to potential abuse and mismanagement resulting in corruption. This study places the Malaysian Government public procurement system under the spotlight zeroing on allegations of abuse, tampering and corrupt practices. The study concluded that the large amount of funds allocated to public procurement coupled with excessive human intervention opportunities opened avenues that increase the risk of system abuse, profiteering and corruption. Case studies on the abuse and corruption of the public procurement system highlight the need for the Malaysian Government to eliminate the loopholes in the system, arrest the rot and implement a transparent, efficient and accountable public procurement system. Approach: Documents from the Ministry of Finance on public procurement including, among others, the Procurement Guideline Book, The Financial Procedures Act 1957, the Treasury Instructions (TI and the Treasury Circular Letter (TCL were scrutinized in studying the Malaysian Government public procurement system, its various attributes, types and processes that reflect a diversified approach to public procurement. Three case studies were cited to illustrate the susceptibility of the system to abuse and corruption. Results: Despite claims of openness and transparency of the public procurement system, it was found the current system is replete with the risk of abuse, unethical manipulations and corrupt practices. This research is limited to the analysis of data and processes related to the Malaysian Government public procurement system. The sensitivity of the subject may inhibit the collection of empirical data via

  12. Asymptotic Stability of Uniformly Bounded Nonlinear Switched Systems

    OpenAIRE

    Jouan, Philippe; Naciri, Said

    2012-01-01

    We study the asymptotic stability properties of nonlinear switched systems under the assumption of the existence of a common weak Lyapunov function. We consider the class of nonchaotic inputs, which generalize the different notions of inputs with dwell-time, and the class of general ones. For each of them we provide some sufficient conditions for asymptotic stability in terms of the geometry of certain sets. The results, which extend those of Balde, Jouan about linear systems, are illustrated...

  13. Weak localization of light in superdiffusive random systems

    CERN Document Server

    Burresi, Matteo; Savo, Romolo; Bertolotti, Jacopo; Vynck, Kevin; Wiersma, Diederik S

    2011-01-01

    L\\'evy flights constitute a broad class of random walks that occur in many fields of research, from animal foraging in biology, to economy to geophysics. The recent advent of L\\'evy glasses allows to study L\\'evy flights in controlled way using light waves. This raises several questions about the influence of superdiffusion on optical interference effects like weak and strong localization. Super diffusive structures have the extraordinary property that all points are connected via direct jumps, meaning that finite-size effects become an essential part of the physical problem. Here we report on the experimental observation of weak localization in L\\'evy glasses and compare results with recently developed optical transport theory in the superdiffusive regime. Experimental results are in good agreement with theory and allow to unveil how light propagates inside a finite-size superdiffusive system.

  14. Subsystem-DFT potential-energy curves for weakly interacting systems.

    Science.gov (United States)

    Schlüns, Danny; Klahr, Kevin; Mück-Lichtenfeld, Christian; Visscher, Lucas; Neugebauer, Johannes

    2015-06-14

    Kohn-Sham density-functional theory (DFT) within the local-density approximation (LDA) or the generalized-gradient approximation (GGA) is known to fail for the correct description of London dispersion interactions. Often, not even bound potential-energy surfaces are obtained for van der Waals complexes, unless special correction schemes are employed. In contrast to that, there has been some evidence for the fact that subsystem-based density functional theory produces interaction energies for weakly bound systems which are superior to Kohn-Sham DFT results without dispersion corrections. This is usually attributed to an error cancellation between the approximate exchange-correlation and non-additive kinetic-energy functionals employed in subsystem DFT. Here, we investigate the accuracy of subsystem DFT for weakly interacting systems in detail, paying special attention to the shape of the potential-energy surfaces (PESs). Our test sets include the extensive S22x5 and S66x8 data sets. Our results indicate that subsystem DFT PESs strongly vary depending on the functional. LDA results are usually quite good, but behave differently from their KS counterparts. GGA results from the popular Perdew-Wang (PW91) set of functionals produce PESs that are often, but not in general overbinding. Results from Becke-Perdew (BP86) GGAs, by contrast, show the typical problems known from the corresponding KS results. We provide some preliminary results for empirical corrections for both PW91 and BP86 in subsystem DFT.

  15. Coupled-channels effects in elastic scattering and near-barrier fusion induced by weakly bound nuclei and exotic halo nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Beck, C. [Institut Pluridisciplinaire Hubert Curien, UMR 7178, IN2P3-CNRS et Universite Louis Pasteur (Strasbourg I), 23 rue du Loess - BP28, F-67037 Strasbourg Cedex 2 (France); Keeley, N. [DSM/DAPNIA/SPhN CEA Saclay, Orme des Merisiers, F-91191 Gif-sur-Yvette Cedex (France); Diaz-Torres, A. [Department of Nuclear Physics, Research School of Physical Sciences and Engineering, The Australian National University, Canberra ACT 0200 (Australia)

    2007-03-15

    The influence on fusion of coupling to the breakup process is investigated for reactions where at least one of the colliding nuclei has a sufficiently low binding energy for breakup to become an important process. Elastic scattering, excitation functions for sub-and near-barrier fusion cross sections, and breakup yields are analyzed for {sup 6,7}Li+{sup 59}Co. Continuum-Discretized Coupled-Channels (CDCC) calculations describe well the data at and above the barrier. Elastic scattering with {sup 6}Li (as compared to {sup 7}Li) indicates the significant role of breakup for weakly bound projectiles. A study of {sup 4,6}He induced fusion reactions with a three-body CDCC method for the {sup 6}He halo nucleus is presented. The relative importance of breakup and bound-state structure effects on total fusion is discussed. (authors)

  16. Stroboscopic prethermalization in weakly interacting periodically driven systems.

    Science.gov (United States)

    Canovi, Elena; Kollar, Marcus; Eckstein, Martin

    2016-01-01

    Time-periodic driving provides a promising route toward engineering nontrivial states in quantum many-body systems. However, while it has been shown that the dynamics of integrable, noninteracting systems can synchronize with the driving into a nontrivial periodic motion, generic nonintegrable systems are expected to heat up until they display a trivial infinite-temperature behavior. In this paper we show that a quasiperiodic time evolution over many periods can also emerge in weakly interacting systems, with a clear separation of the timescales for synchronization and the eventual approach of the infinite-temperature state. This behavior is the analog of prethermalization in quenched systems. The synchronized state can be described using a macroscopic number of approximate constants of motion. We corroborate these findings with numerical simulations for the driven Hubbard model.

  17. Ultraviolet photochemistry and photophysics of weakly-bound (HI){sub 2} clusters via high-n Rydberg time-of-flight spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, J.; Dulligan, M.; Segall, J.; Wen, Y.; Wittig, C. [Univ. of Southern California, Los Angeles, CA (United States)

    1995-09-14

    This paper reports results obtained with (HI){sub 2} clusters under molecular beam conditions that are strongly biased in favor of the formation of binary clusters over higher-than- binary clusters. A preliminary account has been given previously. Pulsed laser photolysis at 266 nm is used to dissociate HI moieties, thereby initiating intracluster reactions, and elastic and inelastic scattering as well as forming weakly-bound radical-molecule clusters. Additionally high laser fluences are used to effect the efficient sequential removal of both hydrogen atoms, opening the door to several intriguing interactions. 34 refs., 15 figs.

  18. Parameter Identification of Weakly Nonlinear Vibration System in Frequency Domain

    Directory of Open Access Journals (Sweden)

    Jiehua Peng

    2004-01-01

    Full Text Available A new method of identifying parameters of nonlinearly vibrating system in frequency domain is presented in this paper. The problems of parameter identification of the nonlinear dynamic system with nonlinear elastic force or nonlinear damping force are discussed. In the method, the mathematic model of parameter identification is frequency response function. Firstly, by means of perturbation method the frequency response function of weakly nonlinear vibration system is derived. Next, a parameter transformation is made and the frequency response function becomes a linear function of the new parameters. Then, based on this function and with the least square method, physical parameters of the system are identified. Finally, the applicability of the proposed technique is confirmed by numerical simulation.

  19. Bounded Nonlinear Control of a Rotating Pendulum System

    Science.gov (United States)

    Luyckx, L.; Loccufier, M.; Noldus, E.

    2004-08-01

    We are interested in the output feedback control of mechanical systems governed by the Euler-Lagrange formalism. The systems are collocated actuator-sensor controlled and underactuated. We present a design method by means of a specific example : the set point control of a rotating pendulum. We use constrained output feedback, whereby the control inputs satisfy a priori imposed upper bounds. The closed loop stability analysis relies on the direct method of Liapunov. This results in a frequency criterion on the controller's linear dynamic component and some restrictions on its nonlinearities. The control parameters are tuned for maximizing closed loop damping.

  20. Density of states of Frenkel excitons in weakly disordered systems

    Science.gov (United States)

    Boukahil, Abdelkrim; Zettili, Nouredine

    2002-04-01

    We present the calculation of the density of states of Frenkel excitons in weakly disordered one , two , and three-dimensional systems. A random distribution of transition frequencies with variance s2 characterizes the disorder. The Coherent Potential Approximation (CPA) calculations show that the density of states (DOS) is very sensitive to any variations in the disorder parameter s. Our calculations are in good agreement with previous work based on the Monte Carlo simulation. One of us (AB) acknowldges the support of the University of Wisconsin--Whitewater for this work through a university research grant.

  1. Existence of positive weak solutions for (, )-Laplacian nonlinear systems

    Indian Academy of Sciences (India)

    Samira Ala; G A Afrouzi; A Niknam

    2015-11-01

    We mainly consider the existence of a positive weak solution of the following system \\begin{equation*} \\left\\{ \\begin{matrix} -_p u + |u|^{p-2} u = [g (x) a(u)+ c(x) f (v)], \\quad \\text{ in } ,\\\\ -_q v + |v|^{q-2} v = [g (x) b(v)+ c(x) h (u)], \\quad \\text{ in } ,\\\\ \\hspace{3cm} u = v = 0, \\hspace{3.8cm} \\text{ on } \\, , \\end{matrix} \\right. \\end{equation*} where $_p u = \\text{ div}(|\

  2. Controlling cooperativity of a metastable open system coupled weakly to a noisy environment

    Institute of Scientific and Technical Information of China (English)

    赵阳

    2015-01-01

    The notion of cooperativity comprises a specific characteristic of a multipartite system concerning its ability to demon-strate a sigmoidal-type response of varying sensitivities to input stimuli in transitions between states under controlled con-ditions. From a statistical physics viewpoint, in this work we attempt to describe the cooperativity by the stability of a metastable open system with respect to irreversibility. To treat the evolution of a system weakly coupled to the environment in a kinetic framework, we consider two fluctuating energy levels of different dimensionalities, initial population of one level, reversible transitions of population between the levels, and irreversible depopulation of another level. An average is made over level fluctuations and environment vibrations so that inter-level transition rate can be obtained accounting for the influences of external control on level position and dimensionality. It is found that the cooperativity of the two-level system is bounded approximately between 0.736 and unity, with the lower bound indicating worsening system stability.

  3. Controlling cooperativity of a metastable open system coupled weakly to a noisy environment

    Science.gov (United States)

    Victor, I. Teslenko; Oleksiy, L. Kapitanchuk; Zhao, Yang

    2015-02-01

    The notion of cooperativity comprises a specific characteristic of a multipartite system concerning its ability to demonstrate a sigmoidal-type response of varying sensitivities to input stimuli in transitions between states under controlled conditions. From a statistical physics viewpoint, in this work we attempt to describe the cooperativity by the stability of a metastable open system with respect to irreversibility. To treat the evolution of a system weakly coupled to the environment in a kinetic framework, we consider two fluctuating energy levels of different dimensionalities, initial population of one level, reversible transitions of population between the levels, and irreversible depopulation of another level. An average is made over level fluctuations and environment vibrations so that an inter-level transition rate can be obtained accounting for the influences of external control on level position and dimensionality. It is found that the cooperativity of the two-level system is bounded approximately between 0.736 and unity, with the lower bound indicating worsening system stability. Project supported by the National Academy of Sciences of Ukraine (Grant No. 0110U007542) and the National Research Foundation of Singapore through the Competitive Research Programme (Grant No. NRF-CRP5-2009-04).

  4. M-MRAC for Nonlinear Systems with Bounded Disturbances

    Science.gov (United States)

    Stepanyan, Vahram; Krishnakumar, Kalmanje

    2011-01-01

    This paper presents design and performance analysis of a modified reference model MRAC (M-MRAC) architecture for a class of multi-input multi-output uncertain nonlinear systems in the presence of bounded disturbances. M-MRAC incorporates an error feedback in the reference model definition, which allows for fast adaptation without generating high frequency oscillations in the control signal, which closely follows the certainty equivalent control signal. The benefits of the method are demonstrated via a simulation example of an aircraft's wing rock motion.

  5. CORCEMA refinement of the bound ligand conformation within the protein binding pocket in reversibly forming weak complexes using STD-NMR intensities

    Science.gov (United States)

    Jayalakshmi, V.; Rama Krishna, N.

    2004-05-01

    We describe an intensity-restrained optimization procedure for refining approximate structures of ligands within the protein binding pockets using STD-NMR intensity data on reversibly forming weak complexes. In this approach, the global minimum for the bound-ligand conformation is obtained by a hybrid structure refinement method involving CORCEMA calculation of intensities and simulated annealing optimization of torsion angles of the bound ligand using STD-NMR intensities as experimental constraints and the NOE R-factor as the pseudo-energy function to be minimized. This method is illustrated using simulated STD data sets for typical carbohydrate and peptide ligands. Our procedure also allows for the optimization of side chain torsion angles of protein residues within the binding pocket. This procedure is useful in refining and improving initial models based on crystallography or computer docking or other algorithms to generate models for the bound ligand (e.g., a lead compound) within the protein binding pocket compatible with solution STD-NMR data. This method may facilitate structure-based drug design efforts.

  6. Millions of Single Cloud Weak MgII Systems

    CERN Document Server

    Churchill, C W; Charlton, J; Churchill, Chris; Rigby, Jane; Charlton, Jane

    2001-01-01

    We report on a population of absorption systems selected by the presence of very weak Mg II doublets. A sub-population of these systems are iron enriched and have near solar metallicities. This would indicated advanced stages (i.e. few Gyr) of in situ star formation within the absorbing structures. From photoionization modeling, we infer low ionization fractions of f(HI/H)~0.01, and gas densities of ~0.1 cm^-3. Since the maximum HI column densities are \\~10^17 cm^-2, the inferred cloud sizes are ~10 pc. From their redshift number densities, this implies that their co-moving spatial density outnumbers normal bright galaxies by a factor of a few million.

  7. The weak, fluctuating, dipole moment of membrane-bound hydrogenase from Aquifex aeolicus accounts for its adaptability to charged electrodes.

    Science.gov (United States)

    Oteri, Francesco; Ciaccafava, Alexandre; de Poulpiquet, Anne; Baaden, Marc; Lojou, Elisabeth; Sacquin-Mora, Sophie

    2014-06-21

    [NiFe] hydrogenases from Aquifex aeolicus (AaHase) and Desulfovibrio fructosovorans (DfHase) have been mainly studied to characterize physiological electron transfer processes, or to develop biotechnological devices such as biofuel cells. In this context, it remains difficult to control the orientation of AaHases on electrodes to achieve a fast interfacial electron transfer. Here, we study the electrostatic properties of these two proteins based on microsecond-long molecular dynamics simulations that we compare to voltammetry experiments. Our calculations show weak values and large fluctuations of the dipole direction in AaHase compared to DfHase, enabling the AaHase to absorb on both negatively and positively charged electrodes, with an orientation distribution that induces a spread in electron transfer rates. Moreover, we discuss the role of the transmembrane helix of AaHase and show that it does not substantially impact the general features of the dipole moment.

  8. Estimates of Some Integral Operators with Bounded Variable Kernels on the Hardy and Weak Hardy Spaces over Rn

    Institute of Scientific and Technical Information of China (English)

    Hua WANG

    2016-01-01

    In this paper, we first introduce Lσ 1-(log L)σ 2 conditions satisfied by the variable kernelsΩ (x, z) for 0 ≤ σ 1 ≤ 1 and σ 2 ≥ 0. Under these new smoothness conditions, we will prove the boundedness properties of singular integral operators TΩ , fractional integrals TΩ ,α and parametric Marcinkiewicz integralsμρΩ with variable kernels on the Hardy spaces Hp(Rn) and weak Hardy spaces WHp(Rn). Moreover, by using the interpolation arguments, we can get some corresponding results for the above integral operators with variable kernels on Hardy–Lorentz spaces Hp,q(Rn) for all p

  9. Why does graphene behave as a weakly interacting system?

    Science.gov (United States)

    Hofmann, Johannes; Barnes, Edwin; Das Sarma, S

    2014-09-05

    We address the puzzling weak-coupling perturbative behavior of graphene interaction effects as manifested experimentally, in spite of the effective fine structure constant being large, by calculating the effect of Coulomb interactions on the quasiparticle properties to next-to-leading order in the random phase approximation (RPA). The focus of our work is graphene suspended in vacuum, where electron-electron interactions are strong and the system is manifestly in a nonperturbative regime. We report results for the quasiparticle residue and the Fermi velocity renormalization at low carrier density. The smallness of the next-to-leading order corrections that we obtain demonstrates that the RPA theory converges rapidly and thus, in contrast to the usual perturbative expansion in the bare coupling constant, constitutes a quantitatively predictive theory of graphene many-body physics for any coupling strength.

  10. The wave function and minimum uncertainty function of the bound quadratic Hamiltonian system

    Science.gov (United States)

    Yeon, Kyu Hwang; Um, Chung IN; George, T. F.

    1994-01-01

    The bound quadratic Hamiltonian system is analyzed explicitly on the basis of quantum mechanics. We have derived the invariant quantity with an auxiliary equation as the classical equation of motion. With the use of this invariant it can be determined whether or not the system is bound. In bound system we have evaluated the exact eigenfunction and minimum uncertainty function through unitary transformation.

  11. Millimeter Wave Spectrum of the Weakly Bound Complex CH2═CHCN·H2O: Structure, Dynamics, and Implications for Astronomical Search.

    Science.gov (United States)

    Calabrese, Camilla; Vigorito, Annalisa; Maris, Assimo; Mariotti, Sergio; Fathi, Pantea; Geppert, Wolf D; Melandri, Sonia

    2015-12-03

    The weakly bound 1:1 complex between acrylonitrile (CH2═CHCN) and water has been characterized spectroscopically in the millimeter wave range (59.6-74.4 GHz) using a Free Jet Absorption Millimeter Wave spectrometer. Precise values of the rotational and quartic centrifugal distortion constants have been obtained from the measured frequencies of the normal and isotopically substituted water moiety (DOH, DOD, H(18)OH). Structural parameters have been estimated from the rotational constants and their differences among isotopologues: the complex has a planar structure with the two subunits held together by a O-H···N (2.331(3) Å) and a C-H···O (2.508(4) Å) interaction. The ab initio intermolecular binding energy, obtained at the counterpoise corrected MP2/aug-cc-pVTZ level of calculation, is De = 24.4 kJ mol(-1).

  12. Fusion and neutron transfer reactions with weakly bound nuclei within time-dependent and coupled channel approaches

    Science.gov (United States)

    Samarin, V. V.

    2016-05-01

    The time-dependent Schrödinger equation and the coupled channel approach based on the method of perturbed stationary two-center states are used to describe nucleon transfers and fusion in low-energy nuclear reactions. Results of the cross sections calculation for the formation of the 198Au and fusion in the 6He+197Au reaction and for the formation of the 65Zn in 6He+64Zn reaction agree satisfactorily with the experimental data near the barrier. The Feynman's continual integrals calculations for a few-body systems were used for the proposal of the new form of the shell model mean field for helium isotopes.

  13. High-viscosity fluid threads in weakly diffusive microfluidic systems

    Science.gov (United States)

    Cubaud, T.; Mason, T. G.

    2009-07-01

    We provide an overview of the flow dynamics of highly viscous miscible liquids in microfluidic geometries. We focus on the lubricated transport of high-viscosity fluids interacting with less viscous fluids, and we review methods for producing and manipulating single and multiple core-annular flows, i.e. viscous threads, in compact and plane microgeometries. In diverging slit microchannels, a thread's buckling instabilities can be employed for generating ordered and disordered miscible microstructures, as well as for partially blending low- and high-viscosity materials. The shear-induced destabilization of a thread that flows off-center in a square microchannel is examined as a means for continuously producing miscible dispersions. We show original compound threads and viscous dendrites that are generated using three fluids, each of which has a large viscosity contrast with the others. Thread motions in zones of microchannel extensions are examined in both miscible and immiscible environments. We demonstrate that high-viscosity fluid threads in weakly diffusive microfluidic systems correspond to the viscous primary flow and can be used as a starting point for studying and understanding the destabilizing effects of interfacial tension as well as diffusion. Characteristic of lubricated transport, threads facilitate the transport of very viscous materials in small fluidic passages, while mitigating dissipation. Threads are also potentially promising for soft material synthesis and diagnostics with independent control of the thread specific surface and residence time in micro-flow reactors.

  14. Existence of Weak Solutions for a Nonlinear Elliptic System

    Directory of Open Access Journals (Sweden)

    Gilbert RobertP

    2009-01-01

    Full Text Available We investigate the existence of weak solutions to the following Dirichlet boundary value problem, which occurs when modeling an injection molding process with a partial slip condition on the boundary. We have in ; in ; , and on .

  15. A branch-and-bound methodology within algebraic modelling systems

    NARCIS (Netherlands)

    Bisschop, J.J.; Heerink, J.B.J.; Kloosterman, G.

    1998-01-01

    Through the use of application-specific branch-and-bound directives it is possible to find solutions to combinatorial models that would otherwise be difficult or impossible to find by just using generic branch-and-bound techniques within the framework of mathematical programming. {\\sc Minto} is an e

  16. Controller Based Observer in Switched System with Norm Bounded Uncertainty

    Directory of Open Access Journals (Sweden)

    Mongi Besbes

    2012-01-01

    Full Text Available Problem statement: This study discusses the robust stabilization of norm bounded discrete switched systems. Approach: The proposed method is using the second Lyapunov approach and the poly-quadratic function concept. The stabilization conditions are written through linear matrix inequality relations. The control law is based on a static output feedback with the use of a switched observer. The synthesis conditions of the controller are written in the form of linear matrix inequalities difficult to resolve by current numerical solvers. That’s why relaxations are proposed to mitigate the pessimism of LMI conditions obtained. Results: The poly-quadratic Lyapunov approach provides a constructive way to tackle uncertainty in the switched framework. The feasibility is illustrated by the example of discrete uncertain switched systems. Conclusion: With these results, the study of stability can be achieved for arbitrary switching laws, state-dependent, time dependent or generated by a controller. However, the implementation of the control law is possible only if the switching status is well known in real time.

  17. Structural superposition in fault systems bounding Santa Clara Valley, California

    Science.gov (United States)

    Graymer, Russell W.; Stanley, Richard G.; Ponce, David A.; Jachens, Robert C.; Simpson, Robert W.; Wentworth, Carl M.

    2015-01-01

    Santa Clara Valley is bounded on the southwest and northeast by active strike-slip and reverse-oblique faults of the San Andreas fault system. On both sides of the valley, these faults are superposed on older normal and/or right-lateral normal oblique faults. The older faults comprised early components of the San Andreas fault system as it formed in the wake of the northward passage of the Mendocino Triple Junction. On the east side of the valley, the great majority of fault displacement was accommodated by the older faults, which were almost entirely abandoned when the presently active faults became active after ca. 2.5 Ma. On the west side of the valley, the older faults were abandoned earlier, before ca. 8 Ma and probably accumulated only a small amount, if any, of the total right-lateral offset accommodated by the fault zone as a whole. Apparent contradictions in observations of fault offset and the relation of the gravity field to the distribution of dense rocks at the surface are explained by recognition of superposed structures in the Santa Clara Valley region.

  18. Mass spectrum bound state systems with relativistic corrections

    Energy Technology Data Exchange (ETDEWEB)

    Dineykhan, M; Zhaugasheva, S A [Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, Dubna (Russian Federation); Toinbaeva, N Sh; Jakhanshir, A [al-Farabi Kazak National University, 480012 Almaty (Kazakhstan)

    2009-07-28

    Based on the investigation of the asymptotic behaviour of the polarization loop function for charged n scalar particles in an external gauge field, we determine the interaction Hamiltonian including relativistic corrections. The mass spectrum of the bound state is analytically derived. The mechanism for arising of the constituent mass of the relativistic bound-state forming particles is explained. The mass and the constituent mass of the two-, three- and n-body relativistic bound states are calculated taking into account relativistic corrections. The corrections arising due to the one- and two-loop electron polarization to the energy spectrum of muonic hydrogen with orbital and radial excitations are calculated.

  19. On the bound states for the Aharonov-Casher systems

    CERN Document Server

    Silva, E O; Belich, H; Filgueiras, C

    2012-01-01

    The bound states for the Aharonov-Casher problem is considered. According to the Hagen's work on the exact equivalence between spin-1/2 Aharonov-Bohm and Aharonov-Casher effects, is known that the $\\boldsymbol{\

  20. Weak Noether symmetry for nonholonomic systems of non-Chetaev type

    Institute of Scientific and Technical Information of China (English)

    Xie Jia-Fang; Gang Tie-Qiang; Mei Feng-Xiang

    2008-01-01

    Baaed on the weak Noether symmetry proposed by Mei F X,this paper discusses the weak Noether symmetry for nonholonomic system of non-Chetaev type,and presents expressions of three kinds of conserved quantities by weak Noether symmetry.Finally,the application of this new results is showed by a practical example.

  1. 39 CFR 501.11 - Reporting Postage Evidencing System security weaknesses.

    Science.gov (United States)

    2010-07-01

    ... timely and efficient procedures for internal reporting of potential security weaknesses and shall provide... weaknesses. 501.11 Section 501.11 Postal Service UNITED STATES POSTAL SERVICE POSTAGE PROGRAMS AUTHORIZATION... security weaknesses. (a) For purposes of this section, provider refers to the Postage Evidencing System...

  2. Fano resonances in Majorana bound states-quantum dot hybrid systems

    Science.gov (United States)

    Schuray, Alexander; Weithofer, Luzie; Recher, Patrik

    2017-08-01

    We consider a quantum wire containing two Majorana bound states (MBS) at its ends that are tunnel-coupled to a current lead on one side and to a quantum dot (QD) on the other side. Using the method of full counting statistics we calculate the conductance and the zero-frequency noise. Using an effective low-energy model, we analyze in detail the Andreev reflection probability as a function of the various system parameters and show that it exhibits a Fano resonance (FR) line shape in the case of a weakly coupled QD as a function of the QD energy level when the two MBS overlap. The asymmetry parameter changes sign as the bias voltage is tuned through the MBS overlap energy. The FR is mirrored as a function of the QD level energy as long as tunneling from the dot to the more distant MBS is negligible. However, if both MBS are coupled to the lead and the QD, the height as well as the asymmetry of the line shapes cease to respect this symmetry. These two exclusive cases uniquely distinguish the coupling to a MBS from the coupling to a fermionic bound state that is shared between the two MBS. We complement the analysis by employing a discretized one-dimensional p -wave superconductor (Kitaev chain) for the quantum wire and show that the features of the effective low-energy model are robust towards a more complete Hamiltonian and also persist at finite temperature.

  3. GLOBAL EXISTENCE OF CLASSICAL SOLUTIONS TO THE CAUCHY PROBLEM ON A SEMI-BOUNDED INITIAL AXIS FOR INHOMOGENEOUS QUASILINEAR HYPERBOLIC SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this paper, we consider the Cauchy problem with initial data given on a semi-bounded axis for inhomogeneous quasilinear hyperbolic systems. Under the assumption that the rightmost (resp. leftmost) eigenvalue is weakly linearly degenerate and the inhomogeneous term satisfies the corresponding matching condition, we obtain the global existence and uniqueness of C1 solution with small and decaying initial data.

  4. Bounded Real Lemma for Generalized Linear System with Finite Discrete Jumps

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The strict bounded real lemma for linear system with finite discrete jumps was considered. Especially,the case where D matrices in the system are not assumed to be zero was dealt. Several versions of the bounded real lemma are presented in terms of solution to Riccati differential equations or inequalities with finite discrete jumps.Both the finite and infinite horizon cases are considered. These results generalize the existed bounded real lemma for linear systems.

  5. Long clinostation influence on the localization of free and weakly bound calcium in cell walls of Funaria hygrometrica moss protonema cells

    Science.gov (United States)

    Nedukha, E. M.

    The pyroantimonate method was used to study the localization of free and weakly bound calcium in cells of moss protonema of Funaria hygrometrica Hedw. cultivated on a clinostat (2 rev/min). Electroncytochemical study of control cells cultivated at 1 g revealed that granular precipitate marked chloroplasts, mitochondria, Golgi apparatus, lipid drops, nucleoplasma, nucleolus, nucleus membranes, cell walls and endoplasmic reticulum. In mitochondria the precipitate was revealed in stroma, in chloroplast it was found on thylakoids and envelope membranes. The cultivation of protonema on clinostat led to the intensification in cytochemical reaction product deposit. A considerable intensification of the reaction was noted in endomembranes, vacuoles, periplasmic space and cell walls. At the same time analysis of pectinase localization was made using the electroncytochemical method. A high reaction intensity in walls in comparison to that in control was found out to be a distinctive pecularity of the cells cultivated on clinostat. It testifies to the fact that increasing of freee calcium concentrations under conditions of clinostation is connected with pectinic substances hydrolysis and breaking of methoxy groups of pectins. Data obtained are discussed in relation to problems of possible mechanisms of disturbance in calcium balance of plant cells and the role of cell walls in gomeostasis of cell grown under conditions of simulated weighlessness.

  6. Global weak solutions in a three-dimensional Keller-Segel-Navier-Stokes system with nonlinear diffusion

    Science.gov (United States)

    Zheng, Jiashan

    2017-09-01

    The coupled quasilinear Keller-Segel-Navier-Stokes system is considered under Neumann boundary conditions for $n$ and $c$ and no-slip boundary conditions for $u$ in three-dimensional bounded domains $\\Omega\\subseteq \\mathbb{R}^3$ with smooth boundary, where $m>0,\\kappa\\in \\mathbb{R}$ are given constants, $\\phi\\in W^{1,\\infty}(\\Omega)$. If $ m> 2$, then for all reasonably regular initial data, a corresponding initial-boundary value problem for $(KSNF)$ possesses a globally defined weak solution.

  7. Non-uniqueness of Admissible Weak Solutions to Compressible Euler Systems with Source Terms

    OpenAIRE

    Luo, Tianwen; Xie, Chunjing; Xin, Zhouping

    2015-01-01

    We consider admissible weak solutions to the compressible Euler system with source terms, which include rotating shallow water system and the Euler system with damping as special examples. In the case of anti-symmetric sources such as rotations, for general piecewise Lipschitz initial densities and some suitably constructed initial momentum, we obtain infinitely many global admissible weak solutions. Furthermore, we construct a class of finite-states admissible weak solutions to the Euler sys...

  8. Bounds on the performance of a class of digital communication systems

    Science.gov (United States)

    Polk, D. R.; Gupta, S. C.; Cohn, D. L.

    1973-01-01

    Bounds on the capacity of a class of digital communication channels are derived. Equating the bounds on capacity to rate-distortion functions of (typical) sources in turn produces bounds on the performance of a class of digital communication systems. For ratios of squared quantization level to noise variance much less than one, the power requirements for this class of digital communication systems are shown to be within approximately 3 dB of the theoretical optimum.

  9. Optical Potential Parameters of Weakly Bound Nuclear System 17F+13C

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>It is well known that optical potential is a basic ingredient in the study of nucleus-nucleus collisions. With the application of radioactive ion beams (RIB), extracting the optical potential parameters for the

  10. The approximate weak inertial manifolds of a class of nonlinear hyperbolic dynamical systems

    Institute of Scientific and Technical Information of China (English)

    赵怡

    1996-01-01

    Some concepts about approximate and semi-approximate weak inertial manifolds are introduced and the existence of global attractor and semi-approximate weak inertial manifolds is obtained for a class of nonlinear hyperbolic dynamical systems by means of some topologically homeomorphic mappings and techniques. Using these results, the existence of approximate weak inertial manifolds is also presented for a kind of nonlinear hyperbolic system arising from relativistic quantum mechanics. The regularization problem is proposed finally.

  11. Shear-induced solidification of athermal systems with weak attraction

    Science.gov (United States)

    Zheng, Wen; Liu, Hao; Xu, Ning

    2016-12-01

    We find that unjammed packings of frictionless particles with rather weak attraction can always be driven into solidlike states by shear. The structure of shear-driven solids evolves continuously with packing fraction from gel-like to jamminglike, but is almost independent of the shear stress. In contrast, both the density of vibrational states (DOVS) and force network evolve progressively with the shear stress. There exists a packing fraction independent shear stress σc, at which the shear-driven solids are isostatic and have a flattened DOVS. Solidlike states induced by a shear stress greater than σc possess properties of marginally jammed solids and are thus strictly defined shear jammed states. Below σc, shear-driven solids with rather different structures are all under isostaticity and share common features in the DOVS and force network. Our study leads to a jamming phase diagram for weakly attractive particles, which reveals the significance of the shear stress in determining properties of shear-driven solids and the connections and distinctions between jamminglike and gel-like states.

  12. Effect of time delay on the upper bound of the time derivative of information entropy in a stochastic dynamical system

    Institute of Scientific and Technical Information of China (English)

    Zhang Min-Min; Wang Can-Jun; Mei Dong-Cheng

    2011-01-01

    The effects of the time delay on the upper bound of the time derivative of information entropy are investigated in a time-delayed dynamical system driven by correlated noise.Using the Markov approximation of the stochastic delay differential equations and the Schwartz inequality principle,we obtain an analytical expression for the upper bound UB(t) of the time derivative of the information entropy.The results show that there is a critical value of T (delay time),and UB(t) presents opposite behaviours on difference sides of the critical value.For the case of the weak additive noise,T can induce a reentrance transition.Delay time T also causes a reversal behaviour in UB(t)-λ plot,where λ denotes the decree of the correlation between the two noises.

  13. Uniqueness of Limit Cycle for the Quadratic Systems with Weak Saddle and Focus

    Institute of Scientific and Technical Information of China (English)

    Shen Qi ZHAO; Ping Guang ZHANG

    2004-01-01

    It is proved that the quadratic system with a weak saddle has at most one limit cycle, and that if this system has a separatrix cycle passing through the weak saddle, then the stability of the separatrix cycle is contrary to that of the singular point surrounded by it.

  14. Continuity in weak topology:higher order linear systems of ODE

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    We will introduce a type of Fredholm operators which are shown to have a certain con- tinuity in weak topologies.From this,we will prove that the fundamental matrix solutions of k-th, k≥2,order linear systems of ordinary differential equations are continuous in coefficient matrixes with weak topologies.Consequently,Floquet multipliers and Lyapunov exponents for periodic systems are continuous in weak topologies.Moreover,for the scalar Hill’s equations,Sturm-Liouville eigenvalues, periodic and anti-periodic eigenvalues,and rotation numbers are all continuous in potentials with weak topologies.These results will lead to many interesting variational problems.

  15. Estimating the ultimate bound and positively invariant set for a generalized Lorenz system

    Institute of Scientific and Technical Information of China (English)

    SHU Yong-lu; ZHANG Yong-hao

    2008-01-01

    A generalized Lyapunov function was employed to investigate the ultimate bound and positively invariant set of a generalized Lorenz system. We derived an ellipsoidal estimate of the ultimate bound and positively invariant set for the generalized Lorenz system, for all the positive values of system parameters a, b, and c. Our results extend the related result of Li, et al. [Li DM, Lu JA, Wu XQ, et al., Estimating the ultimate bound and positively invariant set for the Lorenz system and a unified chaotic system, Journal of Mathematical Analysis and Application, 2006, 323(2): 844-653].

  16. Breakdown of a space charge limited regime of a sheath in a weakly collisional plasma bounded by walls with secondary electron emission.

    Science.gov (United States)

    Sydorenko, D; Kaganovich, I; Raitses, Y; Smolyakov, A

    2009-10-02

    A new regime of plasma-wall interaction is identified in particle-in-cell simulations of a hot plasma bounded by walls with secondary electron emission. Such a plasma has a strongly non-Maxwellian electron velocity distribution function and consists of bulk plasma electrons and beams of secondary electrons. In the new regime, the plasma sheath is not in a steady space charge limited state even though the secondary electron emission produced by the plasma bulk electrons is so intense that the corresponding partial emission coefficient exceeds unity. Instead, the plasma-sheath system performs relaxation oscillations by switching quasiperiodically between the space charge limited and non-space-charge limited states.

  17. Analysis of a kind of Duffing oscillator system used to detect weak signals

    Institute of Scientific and Technical Information of China (English)

    Li Yue; Yang Bao-Jun; Yuan Ye; Liu Xiao-Hua

    2007-01-01

    The stability of the periodic solution of the Duffing oscillator system in the periodic phase state is proved by using the Yoshizaw theorem, which establishes a theoretical basis for using this kind of chaotic oscillator system to detect weak signals. The restoring force term of the system affects the weak-signal detection ability of the system directly,the quantitative relationship between the coefficients of the linear and nonlinear items of the restoring force of the Duffing oscillator system and the SNR in the detection of weak signals is obtained through a large number of simulation experiments, then a new restoring force function with better detection results is established.

  18. Weak-strong uniqueness property for the full Navier-Stokes-Fourier system

    CERN Document Server

    Feireisl, Eduard

    2011-01-01

    The Navier-Stokes-Fourier system describing the motion of a compressible, viscous, and heat conducting fluid is known to possess global-in-time weak solutions for any initial data of finite energy. We show that a weak solution coincides with the strong solution, emanating from the same initial data, as long as the latter exists. In particular, strong solutions are unique within the class of weak solutions.

  19. Overview of DFIG-based Wind Power System Resonances under Weak Networks

    DEFF Research Database (Denmark)

    Song, Yipeng; Blaabjerg, Frede

    2017-01-01

    The wind power generation techniques are continuing to develop and increasing numbers of Doubly Fed Induction Generator (DFIG)-based wind power systems are connecting to the on-shore and off-shore grids, local standalone weak networks, and also micro grid applications. The impedances of the weak...... weak network respectively. This paper will discuss the SSR and the HFR phenomena based on the impedance modeling of the DFIG system and the weak networks, and the cause of these two resonances will be explained in details. The following factors including 1) transformer configuration; 2) different power...... networks are too large to be neglected and require careful attention. Due to the impedance interaction between the weak network and the DFIG system, both Sub- Synchronous Resonance (SSR) and High Frequency Resonance (HFR) may occur when the DFIG system is connected to the series or parallel compensated...

  20. Stabilization of switched linear systems with bounded disturbances and unobservable switchings

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This paper studies the stabilization problem of switched linear systems with bounded disturbances. It is assumed that the system switches among an infinite set of uniformly controllable linear systems, and that the switching signals are not observable, but the switching duration has a lower bound. It will be shown that by combining on-line adaptive estimation and control in the controller design, a feedback control law can be constructed which makes the switched linear system globally stable.

  1. Recent results on stability and response bounds of linear systems - a review

    DEFF Research Database (Denmark)

    Pommer, Christian; Kliem, Wolfhard

    2006-01-01

    of stability and response bounds of linear systems. In addition to reporting some interesting recent stability investigations, the basic concepts of stability are reviewed, and a short introduction to Lyapunov’s direct method is also presented. Particularly important for applications are response bounds...

  2. REGULARITY RESULTS FOR NONLINEAR SYSTEMS OF PARTIAL DIFFERENTIAL EQUATIONS UNDER WEAK ELLIPTICITY CONDITIONS

    Institute of Scientific and Technical Information of China (English)

    Zeng Yuesheng

    2000-01-01

    We prove C1,α almost everywhere regularity for weak solutions in the space W1,k(ΩΩ, RN) of the systems -DαAia(x, u, Du) = Bi(x, u, Du) under the weak / A(x0, u,p + Dφ). Dφdy _> λ/(|DФ|2 + |DФ|k)dy.

  3. Detection of weak stochastic forces in a parametrically stabilized micro-optomechanical system

    NARCIS (Netherlands)

    Pontin, A.; Bonaldi, M.; Borrielli, A.; Cataliotti, F.S.; Marino, F.; Prodi, G.A.; Serra, E.; Marin, F.

    2014-01-01

    Measuring a weak force is an important task for micromechanical systems, both when using devices as sensitive detectors and, particularly, in experiments of quantum mechanics. The optimal strategy for resolving a weak stochastic signal force on a huge background (typically given by thermal noise) is

  4. The inherent weaknesses in industrial control systems devices; hacking and defending SCADA systems

    Science.gov (United States)

    Bianco, Louis J.

    The North American Electric Reliability Corporation (NERC) is about to enforce their NERC Critical Infrastructure Protection (CIP) Version Five and Six requirements on July 1st 2016. The NERC CIP requirements are a set of cyber security standards designed to protect cyber assets essential the reliable operation of the electric grid. The new Version Five and Six requirements are a major revision to the Version Three (currently enforced) requirements. The new requirements also bring substations into scope alongside Energy Control Centers. When the Version Five requirements were originally drafted they were vague, causing in depth discussions throughout the industry. The ramifications of these requirements has made owners look at their systems in depth, questioning how much money it will take to meet these requirements. Some owners saw backing down from routable networks to non-routable as a means to save money as they would be held to less requirements within the standards. Some owners saw removing routable connections as a proper security move. The purpose of this research was to uncover the inherent weaknesses in Industrial Control Systems (ICS) devices; to show how ICS devices can be hacked and figure out potential protections for these Critical Infrastructure devices. In addition, this research also aimed to validate the decision to move from External Routable connectivity to Non-Routable connectivity, as a security measure and not as a means of savings. The results reveal in order to ultimately protect Industrial Control Systems they must be removed from the Internet and all bi-directional external routable connections must be removed. Furthermore; non-routable serial connections should be utilized, and these non-routable serial connections should be encrypted on different layers of the OSI model. The research concluded that most weaknesses in SCADA systems are due to the inherent weaknesses in ICS devices and because of these weaknesses, human intervention is

  5. Weaknesses, Vulnerabilities And Elusion Strategies Against Intrusion Detection Systems

    Directory of Open Access Journals (Sweden)

    Hossein Jadidoleslamy

    2012-09-01

    Full Text Available One of most important existent issues in information security application domain is Intrusion Detection System (IDS; IDS is a defensive-aggressive system to protect information, verifying and responding tooccurring attacks on computer systems and networks. This paper discusses different topics including presenting some strategies against IDSs to passing from them; this leads to improving detection level and performance of IDS; also, this paper considers some intrusion tools, new attacks patterns and trackingprevention techniques. In addition, it discusses vulnerabilities, security holes and IDSs' structural and systemic problems to eliminating defects, reducing penetrates and correcting their behavior. Finally, it leads to increasing the functionality coefficient of IDSs, promoting the security level of computer systems and networks, increasing the trust of authorized users. So, the proposed methods in this paper can apply to improving the IDSs by using inverse engineering methods.

  6. Upper and Lower Bounds of Frequency Interval Gramians for a Class of Perturbed Linear Systems

    DEFF Research Database (Denmark)

    Shaker, Hamid Reza

    2012-01-01

    if the system is controllable or observable, but also it is required to know the degree of controllability or observability of the system. Gramian matrices were introduced to address this issue by providing a quantitative measure for controllability and observability. In many applications, the information...... of uncertain systems. In this paper, we derive upper and lower bounds of frequency interval gramians under perturbations of an A-matrix in the state-space form. These bounds are obtained by solving algebraic Riccati equations. The results are further used to obtain upper and lower bounds of the frequency...

  7. Bound Chains of Tilted Dipoles in Layered Systems

    DEFF Research Database (Denmark)

    G. Volosniev, A.; R. Armstrong, J.; V. Fedorov, D.;

    2012-01-01

    is fascinating. Here we concentrate on few-body states in a multilayered setup. We exploit the geometry of the interlayer potential to calculate the two- and three-body chains with one molecule in each layer. The focus is on dipoles that are aligned at some angle with respect to the layer planes by means...... of an external eletric field. The binding energy and the spatial structure of the bound states are studied in several different ways using analytical approaches. The results are compared to stochastic variational calculations and very good agreement is found. We conclude that approximations based on harmonic...... oscillator potentials are accurate even for tilted dipoles when the geometry of the potential landscape is taken into account....

  8. Quantum feedback in a weakly driven cavity QED system

    Science.gov (United States)

    Reiner, J. E.; Smith, W. P.; Orozco, L. A.; Wiseman, H. M.; Gambetta, Jay

    2004-08-01

    Quantum feedback in strongly coupled systems can probe a regime where one quantum of excitation is a large fluctuation. We present theoretical and experimental studies of quantum feedback in an optical cavity QED system. The time evolution of the conditional state, following a photodetection, can be modified by changing the drive of the cavity. For the appropriate feedback, the conditional state can be captured in a new steady state and then released. The feedback protocol requires resonance operation, and proper amplitude and delay for the change in the drive. We demonstrate the successful use of feedback in the suppression of the vacuum Rabi oscillations for the length of the feedback pulse and their subsequent return to steady state. The feedback works only because we have an entangled quantum system, rather than an analogous correlated classical system.

  9. Impact of Feedback Channel on Measured MIMO Systems and Its Lower Bound

    Institute of Scientific and Technical Information of China (English)

    ZHANGDuo; WEIGuo; ZHUJinkang

    2005-01-01

    A lower bound of the rate in feedback channel from a receiver to a transmitter is presented for measured Multiple-input-multiple-output (MIMO) systems based on the formulae of the open-loop and the closedloop MIMO capacity, under the assumptions of quasi-static block-fading MIMO channel, independent nondispersive fading between each transmit and receive antenna, sampling with the period equal to the reciprocal of the signal bandwidth at the receiver, and zero feedback delay. Through Monte Carlo simulations~ we numerically validate the existence of the lower bound and show numerical results of the bound for system design. Also, we conclude that, the Signal-to-noise ratio (SNR) impacts little on the lower bound of the feedback rate for low antenna numbers, a closed-loop system with a feedback rate less than the lower bound is worse than a open-loop system, and the lower bound remains small with respect to the increase of antenna number for low SNRs. Finally, it is shown that the lower bound of the feedback rate and the conclusions are applicable to practical closed-loop MIMO systems.

  10. Fast Detection of Weak Singularities in a Chaotic Signal Using Lorenz System and the Bisection Algorithm

    Directory of Open Access Journals (Sweden)

    Tiezheng Song

    2012-01-01

    Full Text Available Signals with weak singularities are important for condition monitoring, fault forecasting, and medicine diagnosis. However, the weak singularity in a signal is usually hidden by strong noise. A novel fast method is proposed for detecting a weak singularity in a noised signal by determining a critical threshold towards chaos for the Lorenz system. First, a rough critical threshold value is calculated by local Lyapunov exponents with a step size 0.1. Second, the exact threshold value is calculated by the bisection algorithm. The advantage of the method will not only reduce the computation costs, but also show the weak singular signal which can be accurately identified from strong noise. When the variance of an external signal method embeds into a Lorenz system, according to the parametric equivalent relation between the Lorenz system and the original system, the critical threshold value of the parameter in a Lorenz system is determined.

  11. Interpolation inequalities for weak solutions of nonlinear parabolic systems

    Directory of Open Access Journals (Sweden)

    Floridia Giuseppe

    2011-01-01

    Full Text Available Abstract The authors investigate differentiability of the solutions of nonlinear parabolic systems of order 2 m in divergence form of the following type ∑ | α | ≤ m ( - 1 | α | D α a α X , D u + ∂ u ∂ t = 0 . The achieved results are inspired by the paper of Marino and Maugeri 2008, and the methods there applied. This note can be viewed as a continuation of the study of regularity properties for solutions of systems started in Ragusa 2002, continued in Ragusa 2003 and Floridia and Ragusa 2012 and also as a generalization of the paper by Capanato and Cannarsa 1981, where regularity properties of the solutions of nonlinear elliptic systems with quadratic growth are reached. Mathematics Subject Classification (2000 Primary 35K41, 35K55. Secondary 35B65, 35B45, 35D10

  12. THE COMMUNICATION OF INTERNAL CONTROL SYSTEM WEAKNESSES - NECESSITY AND RESPONSIBILITY

    Directory of Open Access Journals (Sweden)

    Mariana, NEDELCU (BUNEA

    2014-11-01

    Full Text Available In terms of its mission, the control is an inherent part of management, being a specifically human activity, especially useful serving both the management, business partners, public institutions and public. Especially in the last period, amid the economic and financial crisis manifested in recent years, the control has evolved and evolving both by the improvement of organization and management systems and by the response to continuous development of the environment in which it operates. The control activities are an integral part of the management process by which the entity aims to achieve their objectives. The research methodology consists essentially in a literature review and recent regulations in the analyzed field.The objective of this study is to highlight the way in which shall be communicated the deficiencies of internal control systems, to the persons responsible for their governance, inclusively in the banking system.

  13. Weak ferromagnetism and exchange biasing in cobalt oxide nanoparticle systems

    NARCIS (Netherlands)

    Tomou, A; Gournis, D; Panagiotopoulos, [No Value; Huang, Y; Hadjipanayis, GC; Kooi, BJ; Panagiotopoulos, I.

    2006-01-01

    Cobalt oxide nanoparticle systems have been prepared by wet chemical processing involving the encapsulation of the nanoparticles by an organic ligand shell (oleic acid and oleylamine). CoO nanoparticles were easily prepared by this method, while the synthesis of the CoPt/CoO nanocomposites was

  14. Weak ferromagnetism and exchange biasing in cobalt oxide nanoparticle systems

    NARCIS (Netherlands)

    Tomou, A; Gournis, D; Panagiotopoulos, [No Value; Huang, Y; Hadjipanayis, GC; Kooi, BJ; Panagiotopoulos, I.

    2006-01-01

    Cobalt oxide nanoparticle systems have been prepared by wet chemical processing involving the encapsulation of the nanoparticles by an organic ligand shell (oleic acid and oleylamine). CoO nanoparticles were easily prepared by this method, while the synthesis of the CoPt/CoO nanocomposites was achie

  15. WEAKNESSES OF THE MANAGEMENT SYSTEM OF TRADITIONAL HUNGARIAN UNIVERSITIES

    Directory of Open Access Journals (Sweden)

    Gabriella KECZER

    2008-01-01

    Full Text Available Transformation of the management of traditional higher education institutionsemerged in Hungary following the change of the political system in 1990,however, an appropriate answer has not been found to date. The first step inthe management of reform is identification of the issues that need to beresolved through the implementation of changes.The present research has been aimed at identifying the present weaknessesof the inner management system of traditional Hungarian universities, thusfind a solid starting point for reforming it. I conducted in-depth interviews inthe course of research, with 10 top university managers who represent 9institutions, thus the majority of traditional Hungarian universities. Such aresearch has not been made at least for the last decade.In my paper first I present the current legal framework of the system ofuniversity management. Then I give an assessment of it on the basis of theinterviews, analysing the deficiencies, the external and internal obstacles toefficient management I conclude that the present leaders of theuniversities can exactly identify those deficiencies of the system and therelated external and internal circumstances that lead to disturbed operationand low efficiency. The results obtained through the interviews suggest that areform of the internal management should rearrange intra-university powerrelations and harmonize scopes of responsibility and competence. A shifttoward a stronger central, rectoral and a more limited faculty- and bodyrelatedmanagement appears necessary.

  16. A Multi-Fluid Compressible System as the Limit of Weak Solutions of the Isentropic Compressible Navier-Stokes Equations

    Science.gov (United States)

    Bresch, D.; Huang, X.

    2011-08-01

    This paper mainly concerns the mathematical justification of a viscous compressible multi-fluid model linked to the Baer-Nunziato model used by engineers, see for instance I shii (Thermo-fluid dynamic theory of two-phase flow, Eyrolles, Paris, 1975), under a "stratification" assumption. More precisely, we show that some approximate finite-energy weak solutions of the isentropic compressible Navier-Stokes equations converge, on a short time interval, to the strong solution of this viscous compressible multi-fluid model, provided the initial density sequence is uniformly bounded with corresponding Young measures which are linear convex combinations of m Dirac measures. To the authors' knowledge, this provides, in the multidimensional in space case, a first positive answer to an open question, see H illairet (J Math Fluid Mech 9:343-376, 2007), with a stratification assumption. The proof is based on the weak solutions constructed by D esjardins (Commun Partial Differ Equ 22(5-6):977-1008, 1997) and on the existence and uniqueness of a local strong solution for the multi-fluid model established by H illairet assuming initial density to be far from vacuum. In a first step, adapting the ideas from H off and S antos (Arch Ration Mech Anal 188:509-543, 2008), we prove that the sequence of weak solutions built by D esjardins has extra regularity linked to the divergence of the velocity without any relation assumption between λ and μ. Coupled with the uniform bound of the density property, this allows us to use appropriate defect measures and their nice properties introduced and proved by H illairet (Aspects interactifs de la m'ecanique des fluides, PhD Thesis, ENS Lyon, 2005) in order to prove that the Young measure associated to the weak limit is the convex combination of m Dirac measures. Finally, under a non-degeneracy assumption of this combination ("stratification" assumption), this provides a multi-fluid system. Using a weak-strong uniqueness argument, we prove that

  17. Passive Control and ε-Bound Estimation of Singularly Perturbed Systems with Nonlinear Nonlinearities

    Directory of Open Access Journals (Sweden)

    Linna Zhou

    2013-01-01

    Full Text Available This paper considers the problems of passivity analysis and synthesis of singularly perturbed systems with nonlinear uncertainties. By a novel storage function depending on the singular perturbation parameter ε, a new method is proposed to estimate the ε-bound, such that the system is passive when the singular perturbation parameter is lower than the ε-bound. Furthermore, a controller design method is proposed to achieve a predefined ε-bound. The proposed results are shown to be less conservative than the existing ones because the adopted storage function is more general. Finally, an RLC circuit is presented to illustrate the advantages and effectiveness of the proposed methods.

  18. Component C of the methylcoenzyme M methylreductase system contains bound 7-mercaptoheptanoylthreonine phosphate (HS-HTP).

    Science.gov (United States)

    Noll, K M; Wolfe, R S

    1986-09-30

    The structure of component B of the methylcoenzyme M methylreductase system of Methanobacterium thermoautotrophicum was recently found to be 7-mercaptoheptanoylthreonine phosphate (HS-HTP). The work described here demonstrates that this compound is found in two forms: enzyme-free and enzyme-bound. HS-HTP was found to be bound to component C of the methylcoenzyme M methylreductase system. The cofactor extracted from the protein by heat denaturation was found to comigrate with the mixed disulfide of HS-HTP and 2-mercaptoethanol by high-performance liquid chromatography, suggesting HS-HTP is not modified in the bound state.

  19. Strengths and weaknesses of common sustainability indices for multidimensional systems.

    Science.gov (United States)

    Mayer, Audrey L

    2008-02-01

    Sustainability is rapidly moving from an abstract concept to a measurable state of dynamic human-ecological systems. The large number of economic, social, and environmental indicators currently available provides an unwieldy view of system sustainability. To aid policy decisions, these indicators are therefore either presented in the context of a conceptual framework, or quantitatively aggregated into indices. Due to the quantitative nature of sustainability indices, their results may be given more weight by scientists and policy-makers. However, policy decisions can be ineffective or even counterproductive if they do not consider factors which influence index behavior: the scale of the available data and choice of system boundaries; the inclusion, transformation, and weighting of indicator data; and the aggregation method used. As previous reviews have demonstrated, sustainability indices do not rank countries consistently, even when using some of the same indicator data. Several improvements would increase the utility of sustainability indices for policy decisions, particularly the identification of biases introduced by the index methodology and data inclusion. The discrepancy of current sustainability indices due to theoretical or methodological differences supports the use of several complementary indices.

  20. Weak stability for coupled wave and/or Petrovsky systems with complementary frictional damping and infinite memory

    Science.gov (United States)

    Cavalcanti, M. M.; Domingos Cavalcanti, V. N.; Guesmia, A.

    2015-12-01

    In this paper, we consider coupled wave-wave, Petrovsky-Petrovsky and wave-Petrovsky systems in N-dimensional open bounded domain with complementary frictional damping and infinite memory acting on the first equation. We prove that these systems are well-posed in the sense of semigroups theory and provide a weak stability estimate of solutions, where the decay rate is given in terms of the general growth of the convolution kernel at infinity and the arbitrary regularity of the initial data. We finish our paper by considering the uncoupled wave and Petrovsky equations with complementary frictional damping and infinite memory, and showing a strong stability estimate depending only on the general growth of the convolution kernel at infinity.

  1. PARTIAL REGULARITY FOR WEAK SOLUTIONS OF STATIONARY NAVIER-STOKES SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    Chen Shuhong; Tan Zhong

    2008-01-01

    This article is concerned with the partial regularity for the weak solutions of stationary Navier-Stokes system under the controllable growth condition. By A-harmonic approximation technique, the optimal regularity is obtained.

  2. Nonnegative global weak solutions for a degenerate parabolic system modeling thin films driven by capillarity

    CERN Document Server

    Matioc, Bogdan-Vasile

    2011-01-01

    We prove global existence of nonnegative weak solutions for a strongly coupled, fourth order degenerate parabolic system governing the motion of two thin fluid layers in a porous medium when capillarity is the sole driving mechanism.

  3. Estimation variance bounds of importance sampling simulations in digital communication systems

    Science.gov (United States)

    Lu, D.; Yao, K.

    1991-01-01

    In practical applications of importance sampling (IS) simulation, two basic problems are encountered, that of determining the estimation variance and that of evaluating the proper IS parameters needed in the simulations. The authors derive new upper and lower bounds on the estimation variance which are applicable to IS techniques. The upper bound is simple to evaluate and may be minimized by the proper selection of the IS parameter. Thus, lower and upper bounds on the improvement ratio of various IS techniques relative to the direct Monte Carlo simulation are also available. These bounds are shown to be useful and computationally simple to obtain. Based on the proposed technique, one can readily find practical suboptimum IS parameters. Numerical results indicate that these bounding techniques are useful for IS simulations of linear and nonlinear communication systems with intersymbol interference in which bit error rate and IS estimation variances cannot be obtained readily using prior techniques.

  4. Estimation variance bounds of importance sampling simulations in digital communication systems

    Science.gov (United States)

    Lu, D.; Yao, K.

    1991-01-01

    In practical applications of importance sampling (IS) simulation, two basic problems are encountered, that of determining the estimation variance and that of evaluating the proper IS parameters needed in the simulations. The authors derive new upper and lower bounds on the estimation variance which are applicable to IS techniques. The upper bound is simple to evaluate and may be minimized by the proper selection of the IS parameter. Thus, lower and upper bounds on the improvement ratio of various IS techniques relative to the direct Monte Carlo simulation are also available. These bounds are shown to be useful and computationally simple to obtain. Based on the proposed technique, one can readily find practical suboptimum IS parameters. Numerical results indicate that these bounding techniques are useful for IS simulations of linear and nonlinear communication systems with intersymbol interference in which bit error rate and IS estimation variances cannot be obtained readily using prior techniques.

  5. Verified Error Bounds for Isolated Singular Solutions of Polynomial Systems: Case of Breadth One

    CERN Document Server

    Li, Nan

    2012-01-01

    In this paper we describe how to improve the performance of the symbolic-numeric method in (Li and Zhi,2009, 2011) for computing the multiplicity structure and refining approximate isolated singular solutions in the breadth one case. By introducing a parameterized and deflated system with smoothing parameters, we generalize the algorithm in (Rump and Graillat, 2009) to compute verified error bounds such that a slightly perturbed polynomial system is guaranteed to have a breadth-one multiple root within the computed bounds.

  6. On necessity proof of strict bounded real lemma for generalized linear systems with finite discrete jumps

    Institute of Scientific and Technical Information of China (English)

    Xiaojun YANG; Zhengxin WENG; Zuohua TIAN

    2004-01-01

    Some preliminary results on strict bounded real lemma for time-varying continuous linear systems are proposed,where uncertainty in initial conditions,terminal cost and extreme of the cost function are dealt with explicitly.Based on these results,a new recursive approach is proposed in the necessity proof of strict bounded real lemma for generalized linear system with finite discrete jumps.

  7. Boundary-Value Problems for Weakly Nonlinear Delay Differential Systems

    Directory of Open Access Journals (Sweden)

    A. Boichuk

    2011-01-01

    Full Text Available Conditions are derived of the existence of solutions of nonlinear boundary-value problems for systems of n ordinary differential equations with constant coefficients and single delay (in the linear part and with a finite number of measurable delays of argument in nonlinearity: ż(t=Az(t-τ+g(t+εZ(z(hi(t,t,ε,  t∈[a,b], assuming that these solutions satisfy the initial and boundary conditions z(s:=ψ(s if s∉[a,b],  lz(⋅=α∈Rm. The use of a delayed matrix exponential and a method of pseudoinverse by Moore-Penrose matrices led to an explicit and analytical form of sufficient conditions for the existence of solutions in a given space and, moreover, to the construction of an iterative process for finding the solutions of such problems in a general case when the number of boundary conditions (defined by a linear vector functional l does not coincide with the number of unknowns in the differential system with a single delay.

  8. Stability and response bounds of non-conservative linear systems

    DEFF Research Database (Denmark)

    Pommer, Christian

    2003-01-01

    For a linear system of second order differential equations the stability is studied by Lyapunov's direct method. The Lyapunov matrix equation is solved and a sufficient condition for stability is expressed by the system matrices. For a system which satisfies the condition for stability the Lyapunov...

  9. Upper bound on the modal material loss rate in plasmonic and metamaterial systems.

    Science.gov (United States)

    Raman, Aaswath; Shin, Wonseok; Fan, Shanhui

    2013-05-01

    A better understanding of optical loss in plasmonic and metamaterial systems is of increasing importance for both basic and applied research in a broad range of topics including sensors, antennas, optical interconnects, and photovoltaics. In this Letter, we use a photonic band formalism for plasmonics to exactly derive a fundamental upper bound on the nonradiative material loss rate of modes in plasmonic, polaritonic, and metamaterial systems. This bound is purely defined by material properties and cannot be overcome by device design. Moreover it is frequency dependent in the presence of multiple Lorentz poles. We numerically verify this bound through direct calculations for a range of plasmonic systems, including optical antennas where the bound places fundamental performance constraints.

  10. Thermodynamics of small systems two volumes bound as one

    CERN Document Server

    Hill, Terrel L

    1994-01-01

    This authoritative summary of the basics of small system, or nonmacroscopic, thermodynamics was written by the field's founder. Originally published in two volumes, the text remains essential reading in an area in which the practical aim is to derive equations that provide interconnections among various thermodynamic functions. Part I introduces the basics of small system thermodynamics, exploring environmental variables, noting throughout the ways in which small thermodynamic systems differ operationally from macroscopic systems. Part II explores binding on macromolecules and aggregation, completes the discussion of environmental variables, and includes brief summaries of certain special topics, including electric and magnetic fields, spherical drops and bubbles, and polydisperse systems.

  11. Stability of uniformly bounded switched systems and Observability

    OpenAIRE

    Balde, Moussa; Jouan, Philippe; Naciri, Said

    2014-01-01

    This paper mainly deals with switched linear systems defined by a pair of Hurwitz matrices that share a common but not strict quadratic Lyapunov function. Its aim is to give sufficient conditions for such a system to be GUAS.We show that this property of being GUAS is equivalent to the uniform observability on $[0,+\\infty)$ of a bilinear system defined on a subspace whose dimension is in most cases much smaller than the dimension of the switched system.Some sufficient conditions of uniform as...

  12. The bifurcation threshold value of the chaos detection system for a weak signal

    Institute of Scientific and Technical Information of China (English)

    李月; 杨宝俊; 杜立志; 袁野

    2003-01-01

    Recently, it has become an important problem to confirm the bifurcation threshold value of a chaos detectionsystem for a weak signal in the fields of chaos detection. It is directly related to whether the results of chaos detectionare correct or not. In this paper, the discrimination system for the dynamic behaviour of a chaos detection system fora weak signal is established by using the theory of linear differential equation with periodic coefficients and computingthe Lyapunov exponents of the chaos detection system; and then, the movement state of the chaos detection system isdefined. The simulation experiments show that this method can exactly confirm the bifurcation threshold value of thechaos detection system.

  13. Control of Future Air Traffic Systems via Complexity Bound Management

    Science.gov (United States)

    Alexandrov, Natalia

    2013-01-01

    The complexity of the present system for managing air traffic has led to "discreteness" in approaches to creating new concepts: new concepts are created as point designs, based on experience, expertise, and creativity of the proposer. Discrete point designs may be highly successful but they are difficult to substantiate in the face of equally strong substantiation of competing concepts, as well as the state of the art in concept evaluation via simulations. Hybrid concepts may present a compromise - the golden middle. Yet a hybrid of sometimes in principle incompatible concepts forms another point design that faces the challenge of substantiation and validation. We are faced with the need to re-design the air transportation system ab initio. This is a daunting task, especially considering the problem of transitioning from the present system to any fundamentally new system. However, design from scratch is also an opportunity to reconsider approaches to new concept development. In this position paper we propose an approach, Optimized Parametric Functional Design, for systematic development of concepts for management and control of airspace systems, based on optimization formulations in terms of required system functions and states. This reasoning framework, realizable in the context of ab initio system design, offers an approach to deriving substantiated airspace management and control concepts. With growing computational power, we hope that the approach will also yield a methodology for actual dynamic control of airspace

  14. Strong, Weak and Branching Bisimulation for Transition Systems and Markov Reward Chains: A Unifying Matrix Approach

    CERN Document Server

    Trčka, Nikola

    2009-01-01

    We first study labeled transition systems with explicit successful termination. We establish the notions of strong, weak, and branching bisimulation in terms of boolean matrix theory, introducing thus a novel and powerful algebraic apparatus. Next we consider Markov reward chains which are standardly presented in real matrix theory. By interpreting the obtained matrix conditions for bisimulations in this setting, we automatically obtain the definitions of strong, weak, and branching bisimulation for Markov reward chains. The obtained strong and weak bisimulations are shown to coincide with some existing notions, while the obtained branching bisimulation is new, but its usefulness is questionable.

  15. Strong, Weak and Branching Bisimulation for Transition Systems and Markov Reward Chains: A Unifying Matrix Approach

    Directory of Open Access Journals (Sweden)

    Nikola Trčka

    2009-12-01

    Full Text Available We first study labeled transition systems with explicit successful termination. We establish the notions of strong, weak, and branching bisimulation in terms of boolean matrix theory, introducing thus a novel and powerful algebraic apparatus. Next we consider Markov reward chains which are standardly presented in real matrix theory. By interpreting the obtained matrix conditions for bisimulations in this setting, we automatically obtain the definitions of strong, weak, and branching bisimulation for Markov reward chains. The obtained strong and weak bisimulations are shown to coincide with some existing notions, while the obtained branching bisimulation is new, but its usefulness is questionable.

  16. Robust levitation control for maglev systems with guaranteed bounded airgap.

    Science.gov (United States)

    Xu, Jinquan; Chen, Ye-Hwa; Guo, Hong

    2015-11-01

    The robust control design problem for the levitation control of a nonlinear uncertain maglev system is considered. The uncertainty is (possibly) fast time-varying. The system has magnitude limitation on the airgap between the suspended chassis and the guideway in order to prevent undesirable contact. Furthermore, the (global) matching condition is not satisfied. After a three-step state transformation, a robust control scheme for the maglev vehicle is proposed, which is able to guarantee the uniform boundedness and uniform ultimate boundedness of the system, regardless of the uncertainty. The magnitude limitation of the airgap is guaranteed, regardless of the uncertainty. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  17. Maximum-likelihood detection based on branch and bound algorithm for MIMO systems

    Institute of Scientific and Technical Information of China (English)

    LI Zi; CAI YueMing

    2008-01-01

    Maximum likelihood detection for MIMO systems can be formulated as an integer quadratic programming problem. In this paper, we introduce depth-first branch and bound algorithm with variable dichotomy into MIMO detection. More nodes may be pruned with this structure. At each stage of the branch and bound algorithm, active set algorithm is adopted to solve the dual subproblem. In order to reduce the com- plexity further, the Cholesky factorization update is presented to solve the linear system at each iteration of active set algorithm efficiently. By relaxing the pruning conditions, we also present the quasi branch and bound algorithm which imple- ments a good tradeoff between performance and complexity. Numerical results show that the complexity of MIMO detection based on branch and bound algorithm is very low, especially in low SNR and large constellations.

  18. On the emergence of quantum mechanics, diffeomorphism invariance and the weak equivalence principle from deterministic Cartan-Randers systems

    CERN Document Server

    Torromé, Ricardo Gallego

    2014-01-01

    In this work, deterministic Cartan-Randers dynamical systems, a particular class of {\\it deterministic quantum models} associated to first order ordinary differential equations are considered. Then we show that {\\it diffeomorphism invariance}, a classical and a quantum versions of a Principle of Inertia, reversibility of the effective quantum dynamics and a {\\it covariant maximal universal acceleration} emerge from deterministic Cartan-Randers models. A geometric analytic mechanism for quantum measurement processes without reduction of wave packet appears naturally. The mechanism is applied heuristically to the quantum two slit experiment. The mechanism allows for protective measurement and usual Von Neumann measurements. Furthermore, a similar geometric-analytic mechanism is discovered to produce a lower bound for physical values for the eigenvalues of Hamiltonian for matter. As a side effect of such mechanism, a natural explanation for the Weak Equivalence Principle is obtained. This fact together with the ...

  19. Linear and Weakly Nonlinear Stability Analyses of Turing Patterns for Diffusive Predator-Prey Systems in Freshwater Marsh Landscapes.

    Science.gov (United States)

    Zhang, Li; Zhang, Fan; Ruan, Shigui

    2017-03-01

    We study a diffusive predator-prey model describing the interactions of small fishes and their resource base (small invertebrates) in the fluctuating freshwater marsh landscapes of the Florida Everglades. The spatial model is described by a reaction-diffusion system with Beddington-DeAngelis functional response. Uniform bound, local and global asymptotic stability of the steady state of the PDE model under the no-flux boundary conditions are discussed in details. Sufficient conditions on the Turing (diffusion-driven) instability which induces spatial patterns in the model are derived via linear analysis. Existence of one-dimensional and two-dimensional spatial Turing patterns, including rhombic and hexagonal patterns, are established by weakly nonlinear analyses. These results provide theoretical explanations and numerical simulations of spatial dynamical behaviors of the wetland ecosystems of the Florida Everglades.

  20. Oscillatory Behavior of In-medium Interparticle Potential in Hot Gauge System with Scalar Bound States

    Institute of Scientific and Technical Information of China (English)

    LIU Hui; HOU De-Fu; LI Jia-Rong

    2009-01-01

    We investigate the in-medium interparticle potential of hot gauge system with bound states by employing the QED and scalar QED coupling. At the finite temperature an oscillatory behavior of the potential has been found as well as its variation in terms of different free parameters. We expect the competition among the parameters will lead to an appropriate interparticle potential, which could be extended to discuss the fluid properties of QGP with scalar bound states.

  1. Upper bounds on the number of Steiner triple systems and 1-factorizations

    CERN Document Server

    Linial, Nathan

    2011-01-01

    Let STS(n) denote the number of Steiner triple systems on n vertices, and let F(n) denote the number of 1-factorizations of the complete graph on n vertices. We prove the following upper bounds. STS(n) <= ((1 + o(1)) (n/e^2))^(n^2/6) F(n) <= ((1 + o(1)) (n/e^2))^(n^2/2) Both bounds are conjectured be sharp. Our main tool is the entropy method.

  2. On accurate computations of bound state properties in three- and four-electron atomic systems

    CERN Document Server

    Frolov, Alexei M

    2016-01-01

    Results of accurate computations of bound states in three- and four-electron atomic systems are discussed. Bound state properties of the four-electron lithium ion Li$^{-}$ in its ground $2^{2}S-$state are determined from the results of accurate, variational computations. We also consider a closely related problem of accurate numerical evaluation of the half-life of the beryllium-7 isotope. This problem is of paramount importance for modern radiochemistry.

  3. Hojman conserved quantity deduced by weak Noether symmetry for Lagrange systems

    Institute of Scientific and Technical Information of China (English)

    Xie Jia-Fang; Gang Tie-Qiang; Mei Feng-Xiang

    2008-01-01

    This paper studies the Hojman conserved quantity,a non-Noether conserved quantity,deduced by special weak Noether symmetry for Lagrange systems.Under special infinitesimal transformations in which the time is not variable,its criterion is given and a method of how to seek the Hojman conserved quantity is presented.A Hojman conserved quantity can be found by using the special weak Noether symmetry.

  4. Reachability bounds for chemical reaction networks and strand displacement systems.

    Science.gov (United States)

    Condon, Anne; Kirkpatrick, Bonnie; Maňuch, Ján

    2014-01-01

    Chemical reaction networks (CRNs) and DNA strand displacement systems (DSDs) are widely-studied and useful models of molecular programming. However, in order for some DSDs in the literature to behave in an expected manner, the initial number of copies of some reagents is required to be fixed. In this paper we show that, when multiple copies of all initial molecules are present, general types of CRNs and DSDs fail to work correctly if the length of the shortest sequence of reactions needed to produce any given molecule exceeds a threshold that grows polynomially with attributes of the system.

  5. Bound Motion of Bodies and Paticles in the Rotating Systems

    Science.gov (United States)

    Pardy, Miroslav

    2007-04-01

    The Lagrange theory of particle motion in the noninertial systems is applied to the Foucault pendulum, isosceles triangle pendulum and the general triangle pendulum swinging on the rotating Earth. As an analogue, planet orbiting in the rotating galaxy is considered as the giant galactic gyroscope. The Lorentz equation and the Bargmann-Michel-Telegdi equations are generalized for the rotation system. The knowledge of these equations is inevitable for the construction of LHC where each orbital proton “feels” the Coriolis force caused by the rotation of the Earth.

  6. Applied Bounded Model Checking for Interlocking System Designs

    DEFF Research Database (Denmark)

    Haxthausen, Anne Elisabeth; Peleska, Jan; Pinger, Ralf

    2013-01-01

    In this article the verification and validation of interlocking systems is investigated. Reviewing both geographical and route-related interlocking, the verification objectives can be structured from a perspective of computer science into (1) verification of static semantics, and (2) verification...

  7. Applied Bounded Model Checking for Interlocking System Designs

    DEFF Research Database (Denmark)

    Haxthausen, Anne Elisabeth; Peleska, Jan; Pinger, Ralf

    2014-01-01

    of behavioural (operational) semantics. The former checks that the plant model – that is, the software components reflecting the physical components of the interlocking system – has been set up in an adequate way. The latter investigates trains moving through the network, with the objective to uncover potential...

  8. The Upper Bound for GMRES on Normal Tridiagonal Toeplitz Linear System

    Directory of Open Access Journals (Sweden)

    R. Doostaki∗

    2015-09-01

    Full Text Available The Generalized Minimal Residual method (GMRES is often used to solve a large and sparse system Ax = b. This paper establishes error bound for residuals of GMRES on solving an N × N normal tridiagonal Toeplitz linear system. This problem has been studied previously by Li [R.-C. Li, Convergence of CG and GMRES on a tridiagonal Toeplitz linear system, BIT 47 (3 (2007 577-599.], for two special right-hand sides b = e1, eN . Also, Li and Zhang [R.-C. Li, W. Zhang, The rate of convergence of GMRES on a tridiagonal Toeplitz linear system, Numer. Math. 112 (2009 267-293.] for non-symmetric matrix A, presented upper bound for GMRES residuals. But in this paper we establish the upper bound on normal tridiagonal Toeplitz linear systems for special right-hand sides b = b(lel, for 1  l  N

  9. Study on I/O response time bounds of networked storage systems

    Institute of Scientific and Technical Information of China (English)

    CUI Bao-jiang; LIU Jun; WANG Gang; LIU Jing

    2006-01-01

    In order to predict and improve the performance of networked storage systems,this paper explored the relationship between the system I/O response time and its performance factors by quantitative analytical method.Through analyzing data flow in networked RAID storage system,we established its analytical model utilizing closed queueing networks and studied the performance bounds of the system I/O response time.Experimental results show that the theoretical bounds are found to be in agreement with the actual performance bounds of the networked RAID storage system and reflect the dynamic trend of its actual performance.Furthermore,it concludes that the CPU processing power and cache hit rate of the central storage server are the key factors affecting the I/O response time as the concurrent jobs are lower,while the network bandwidth and cache hit rate of the central storage server become the key factors as the concurrent jobs go higher.

  10. Existence of bounded positive solutions of a nonlinear differential system

    Directory of Open Access Journals (Sweden)

    Sabrine Gontara

    2012-04-01

    Full Text Available In this article, we study the existence and nonexistence of solutions for the system $$displaylines{ frac{1}{A}(Au''=pu^{alpha }v^{s}quad hbox{on }(0,infty , cr frac{1}{B}(Bu''=qu^{r}v^{eta }quad hbox{on }(0,infty , cr Au'(0=0,quad u(infty =a>0, cr Bv'(0=0,quad v(infty =b>0, }$$ where $alpha ,eta geq 1$, $s,rgeq 0$, p,q are two nonnegative functions on $(0,infty $ and A, B satisfy appropriate conditions. Using potential theory tools, we show the existence of a positive continuous solution. This allows us to prove the existence of entire positive radial solutions for some elliptic systems.

  11. Delta-Complete Analysis for Bounded Reachability of Hybrid Systems

    Science.gov (United States)

    2014-07-16

    can occur in realistic hybrid sys- tems, such as polynomials, trigonometric functions , and solutions of Lipschitz-continuous ODEs. The goal of this...systems are Type 2 computable, such as polynomials, exponentiation, logarithm, trigonometric functions , and solution functions of Lipschitz-continuous...comes from the need of solving logic formulas over the real numbers with nonlinear functions , which is notoriously hard. Recently, we have defined the δ

  12. Experimental performance bounds of MIMO-FBMC/OQAM systems

    OpenAIRE

    Caus, Màrius; Pérez-Neira, Ana Isabel

    2010-01-01

    This paper addresses the application of filter bank multicarrier (FBMC) systems to multiple-input-multiple-output (MIMO) channels. In particular, it is investigated the FBMC modulation based on OQAM, known as FBMC/OQAM. Existing solutions reveal that FBMC/OQAM remains competitive with the orthogonal frequency division multiplexing (OFDM) technique when the number of streams (S), transmit antennas (NT ) and receive antennas (NR) are related as follows: S = min(NT ,NR). State-of-the-art techniq...

  13. High-speed demodulation system of identical weak FBGs based on FDML wavelength swept laser

    Science.gov (United States)

    Wang, Yiming; Liu, Quan; Wang, Honghai; Hu, Chenchen; Zhang, Chun; Li, Zhengying

    2017-04-01

    An identical weak reflection FBGs demodulation system based on a FDML laser is proposed. The laser is developed to output a continuous wavelength-swept spectrum in the scanning frequency of 120 kHz over a spectral range of more than 10nm at 1.54 μm. Based on this high-speed wavelength-swept light and the optical transmission delay effect, the demodulation system obtains the location and wavelength information of all identical weak FBGs by the reflected spectrum within each scanning cycle. By accessing to a high-speed FPGA processing module, continuous demodulation of 120 kHz is realized. The system breakthroughs the bandwidth of the laser to expand the sensors capacity and greatly improves the demodulation speed of a TDM sensing network. The experiments show the system can distinguish and demodulate the identical weak FBGs and measure the 4 kHz vibration at 120 kHz demodulation speed.

  14. Mechanizing Weakly Ground Termination Proving of Term Rewriting Systems by Structural and Cover-Set Inductions

    Institute of Scientific and Technical Information of China (English)

    Su Feng

    2005-01-01

    The paper presents three formal proving methods for generalized weakly ground terminating property, i.e.,weakly terminating property in a restricted domain of a term rewriting system, one with structural induction, one with cover-set induction, and the third without induction, and describes their mechanization based on a meta-computation model for term rewriting systems-dynamic term rewriting calculus. The methods can be applied to non-terminating, nonconfluent and/or non-left-linear term rewriting systems. They can do "forward proving" by applying propositions in the proof, as well as "backward proving" by discovering lemmas during the proof.

  15. A convergence analysis of SOR iterative methods for linear systems with weak H-matrices

    Directory of Open Access Journals (Sweden)

    Zhang Cheng-yi

    2016-01-01

    Full Text Available It is well known that SOR iterative methods are convergent for linear systems, whose coefficient matrices are strictly or irreducibly diagonally dominant matrices and strong H-matrices (whose comparison matrices are nonsingular M-matrices. However, the same can not be true in case of those iterative methods for linear systems with weak H-matrices (whose comparison matrices are singular M-matrices. This paper proposes some necessary and sufficient conditions such that SOR iterative methods are convergent for linear systems with weak H-matrices. Furthermore, some numerical examples are given to demonstrate the convergence results obtained in this paper.

  16. Adaptive Control of Networked Systems in the Presence of Bounded Disturbances

    Directory of Open Access Journals (Sweden)

    A. H. Tahoun

    2007-01-01

    Full Text Available The insertion of data network in the feedback adaptive control loops makes the analysis and design of networked control systems more complex than traditional control systems. This paper addresses the adaptive stabilization problem of linear time-invariant networked control systems when the measurements of the plant states are corrupted by bounded disturbances. The case of state feedback is treated in which only an upper bound on the norm of matrix A is needed. The problem is to find an upper bound on the transmission period h that guarantees the stability of the overall adaptive networked control system under an ideal transmission process, i.e. no transmission delay or packet dropout. Rigorous mathematical proofs are established, that relies heavily on Lyapunov's stability criterion and dead-zone Technique. Simulation results are given to illustrate the efficacy of our design approach.

  17. Stability analysis and design of fuzzy control system with bounded uncertain delays

    Institute of Scientific and Technical Information of China (English)

    Jianguo GUO; Juntao LI; Fengqi ZHOU; Jun ZHOU

    2005-01-01

    Fuzzy control problems for systems with bounded uncertain delays were studied.Based on Lyapunov stability theory and matrix theory,a nonlinear state feedback fuzzy controller was designed by linear matrix inequalities (LMI) approach,and the global exponential stability of the closed-loop system was strictly proved.For a fuzzy control system with bounded uncertain delays,under the global exponential stability condition which is reduced to p linear matrix inequalities,the controller guarantees stability performances of state variables.Finally,the simulation shows the validity of the method in this paper.

  18. Delay and Its Time-Derivative Dependent Bounded Real Lemma for Linear Time-Delay Systems

    Institute of Scientific and Technical Information of China (English)

    JIANGXiefu; XUWenli

    2004-01-01

    Based on an appropriate Lyapunov-Krasovskii functional, this paper deals with the problem of the bounded real lemma for linear continuous-time systems with state delay. The system under consideration involves state time-varying time-delay. A sufficient condition for the system to possess a H∞-norm that is less than a prescribed level, is presented in a Linear matrix inequality(LMI) form which is dependent on both the size of timedelay and the size of its time-derivative. Due to that fewercross terms should be bounded, our result is less conservative. Finally, an example is presented to demonstrate the effectiveness of our result.

  19. Mean-square boundedness of stochastic networked control systems with bounded control inputs

    CERN Document Server

    Chatterjee, Debasish; Hokayem, Peter; Lygeros, John; Sastry, S Shankar

    2010-01-01

    We consider the problem of controlling marginally stable linear systems using bounded control inputs for networked control settings in which the communication channel between the remote controller and the system is unreliable. We assume that the states are perfectly observed, but the control inputs are transmitted over a noisy communication channel. Under mild hypotheses on the noise introduced by the control communication channel and large enough control authority, we construct a control policy that renders the state of the closed-loop system mean-square bounded.

  20. Universal localizing bounds for compact invariant sets of natural polynomial Hamiltonian systems

    Energy Technology Data Exchange (ETDEWEB)

    Starkov, Konstantin E. [CITEDI-IPN, Av. del Parque 1310, Mesa de Otay, Tijuana, BC (Mexico)], E-mail: konst@citedi.mx

    2008-10-06

    In this Letter we study the localization problem of compact invariant sets of natural Hamiltonian systems with a polynomial Hamiltonian. Our results are based on applying the first order extremum conditions. We compute universal localizing bounds for some domain containing all compact invariant sets of a Hamiltonian system by using one quadratic function of a simple form. These bounds depend on the value of the total energy of the system, degree and some coefficients of a potential and, in addition, some positive number got as a result of a solution of one maximization problem. Besides, under some quasihomogeneity condition(s) we generalize our construction of the localization set.

  1. Excited, bound and resonant positron-atom systems

    Energy Technology Data Exchange (ETDEWEB)

    Bromley, M W J [Department of Physics and Computational Science Research Center, San Diego State University, San Diego CA 92182 (United States); Mitroy, J, E-mail: mbromley@physics.sdsu.ed [ARC Centre for Antimatter-Matter Studies and Faculty of Education, Health and Science, Charles Darwin University, Darwin NT 0909 (Australia)

    2010-01-01

    Calculations have demonstrated that eleven neutral atoms can bind positrons, while many more can bind positronium. This is a short review of recent progress made in understanding some of the underlying mechanisms. The emphasis here being on configuration interaction calculations with excited state configurations. These have demonstrated the existence of a {sup 2}P{sup o} excited state of e{sup +}Ca, which consists predominantly of a positronium cluster orbiting the Ca{sup +} ion in the L = 1 partial wave. Preliminary results are presented of excited state positron binding to a model alkali atom, where the excited {sup 1}P{sup o} states are stable over a limited region. Implications for the unnatural parity, {sup 2,4}S{sup o}, states of PsH, LiPs, NaPs and KPs are also discussed. The e{sup +}Mg, e{sup +}Cu, e{sup +}Zn and e{sup +}Cd systems show a lack of a {sup 2}P{sup o} excited state, each instead possessing a low-energy p-wave shape resonance of varying strength.

  2. Positive Root Bounds and Root Separation Bounds

    Science.gov (United States)

    Herman, Aaron Paul

    In this thesis, we study two classes of bounds on the roots of a polynomial (or polynomial system). A positive root bound of a polynomial is an upper bound on the largest positive root. A root separation bound of a polynomial is a lower bound on the distance between the roots. Both classes of bounds are fundamental tools in computer algebra and computational real algebraic geometry, with numerous applications. In the first part of the thesis, we study the quality of positive root bounds. Higher quality means that the relative over-estimation (the ratio of the bound and the largest positive root) is smaller. We find that all known positive root bounds can be arbitrarily bad. We then show that a particular positive root bound is tight for certain important classes of polynomials. In the remainder of the thesis, we turn to root separation bounds. We observe that known root separation bounds are usually very pessimistic. To our surprise, we also find that known root separation bounds are not compatible with the geometry of the roots (unlike positive root bounds). This motivates us to derive new root separation bounds. In the second part of this thesis, we derive a new root separation for univariate polynomials by transforming a known bound into a new improved bound. In the third part of this thesis, we use a similar strategy to derive a new improved root separation bound for polynomial systems.

  3. Computing variable bounds in the conceptual design phase of guided weapon systems

    NARCIS (Netherlands)

    Weiss, M.; Buco, D.

    2012-01-01

    The performance of guided weapon systems is primarily expressed by the end-of-flight effect, routinely approximated by the miss distance. It is however equally important that certain system variables of interest are kept within given bounds all along the duration of the flight. In this paper, we pro

  4. Computing variable bounds in the conceptual design phase of guided weapon systems

    NARCIS (Netherlands)

    Weiss, M.; Buco, D.

    2012-01-01

    The performance of guided weapon systems is primarily expressed by the end-of-flight effect, routinely approximated by the miss distance. It is however equally important that certain system variables of interest are kept within given bounds all along the duration of the flight. In this paper, we

  5. Design of bounded feedback controls for linear dynamical systems by using common Lyapunov functions

    Institute of Scientific and Technical Information of China (English)

    Igor; Ananievskii; Nickolai; Anokhin; Alexander; Ovseevich

    2011-01-01

    For a linear dynamical system,we address the problem of devising a bounded feedback control,which brings the system to the origin in finite time.The construction is based on the notion of a common Lyapunov function.It is shown that the constructed control remains effective in the presence of small perturbations.

  6. Upper bound for energy efficiency in multi-cell fibre-wireless access systems

    DEFF Research Database (Denmark)

    Koonen, A.M.J.; Popov, M.; Wessing, Henrik

    2013-01-01

    Bringing radio access points closer to the end-users improves radio energy efficiency. However, taking into account both the radio and the optical parts of a fibre-wireless access system, the overall system energy efficiency has an upper bound determined by the relation between the energy...

  7. Upper Bound for Energy Efficiency in Multi-Cell Fibre-Wireless Access Systems

    DEFF Research Database (Denmark)

    Koonen, A. M. J.; Popov, M.; Wessing, Henrik

    Bringing radio access points closer to the end-users improves radio energy efficiency. However, taking into account both the radio and the optical parts of a fibre-wireless access system, the overall system energy efficiency has an upper bound determined by the relation between the energy...

  8. Partial regularity of weak solutions for Landau-Lifshitz system with potential

    Institute of Scientific and Technical Information of China (English)

    CHU YuMing; LIU XianGao

    2009-01-01

    In this note, we prove the partial regularity of stationary weak solutions for the Landau-Lifshitz system with general potential in four or three dimensional space. As well known, in general, since the constraint of the methods, in order to get the partial regularity of stationary weak solution of the Landau-Lifshitz system with potential, we need to add some very strongly conditions on the potential. The main difficulty caused by potential is how to find the equation satisfied by the scaling function, which breaks down the blow-up processing. We estimate directly Morrey's energy to avoid the difficulties by blowing up.

  9. Partial regularity of weak solutions for Landau-Lifshitz system with potential

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In this note, we prove the partial regularity of stationary weak solutions for the Landau- Lifshitz system with general potential in four or three dimensional space. As well known, in general, since the constraint of the methods, in order to get the partial regularity of stationary weak solution of the Landau-Lifshitz system with potential, we need to add some very strongly conditions on the potential. The main difficulty caused by potential is how to find the equation satisfied by the scaling function, which breaks down the blow-up processing. We estimate directly Morrey’s energy to avoid the difficulties by blowing up.

  10. The Population of Weak MgII Absorbers. II The Properties of Single-Cloud Systems

    CERN Document Server

    Rigby, J R; Churchill, C W; Rigby, Jane R.; Charlton, Jane C.; Churchill, Christopher W.

    2001-01-01

    We present an investigation of MgII absorbers characterized as single-cloud weak systems at z~1. We measured column densities and Doppler parameters for MgII and FeII in 15 systems found in HIRES/Keck spectra at 6.6 km/s. Using these quantities and CIV, Lyman alpha and Lyman limit absorption observed with FOS/HST (resolution ~230 km/s) we applied photoionization models to each system to constrain metallicities, densities, ionization conditions, and sizes. We find that: (1) Single-cloud weak systems are optically thin in neutral hydrogen and may have their origins in a population of objects distinct from the optically thick strong MgII absorbers, which are associated with bright galaxies. (2) Weak systems account for somewhere between 25% to 100% of the z < 1 Lyman alpha forest clouds in the range 15.8systems have two or more ionization phases of gas (multiphase medium). (4) We identify a subset of weak MgII absorber that we term ``iron-rich''. These clo...

  11. Stochastic Resonance in an Underdamped System with Pinning Potential for Weak Signal Detection

    Directory of Open Access Journals (Sweden)

    Haibin Zhang

    2015-08-01

    Full Text Available Stochastic resonance (SR has been proved to be an effective approach for weak sensor signal detection. This study presents a new weak signal detection method based on a SR in an underdamped system, which consists of a pinning potential model. The model was firstly discovered from magnetic domain wall (DW in ferromagnetic strips. We analyze the principle of the proposed underdamped pinning SR (UPSR system, the detailed numerical simulation and system performance. We also propose the strategy of selecting the proper damping factor and other system parameters to match a weak signal, input noise and to generate the highest output signal-to-noise ratio (SNR. Finally, we have verified its effectiveness with both simulated and experimental input signals. Results indicate that the UPSR performs better in weak signal detection than the conventional SR (CSR with merits of higher output SNR, better anti-noise and frequency response capability. Besides, the system can be designed accurately and efficiently owing to the sensibility of parameters and potential diversity. The features also weaken the limitation of small parameters on SR system.

  12. Stochastic Resonance in an Underdamped System with Pinning Potential for Weak Signal Detection.

    Science.gov (United States)

    Zhang, Haibin; He, Qingbo; Kong, Fanrang

    2015-08-28

    Stochastic resonance (SR) has been proved to be an effective approach for weak sensor signal detection. This study presents a new weak signal detection method based on a SR in an underdamped system, which consists of a pinning potential model. The model was firstly discovered from magnetic domain wall (DW) in ferromagnetic strips. We analyze the principle of the proposed underdamped pinning SR (UPSR) system, the detailed numerical simulation and system performance. We also propose the strategy of selecting the proper damping factor and other system parameters to match a weak signal, input noise and to generate the highest output signal-to-noise ratio (SNR). Finally, we have verified its effectiveness with both simulated and experimental input signals. Results indicate that the UPSR performs better in weak signal detection than the conventional SR (CSR) with merits of higher output SNR, better anti-noise and frequency response capability. Besides, the system can be designed accurately and efficiently owing to the sensibility of parameters and potential diversity. The features also weaken the limitation of small parameters on SR system.

  13. Bounded Model Checking and Inductive Verification of Hybrid Discrete-Continuous Systems

    DEFF Research Database (Denmark)

    Becker, Bernd; Behle, Markus; Eisenbrand, Fritz

    2004-01-01

    We present a concept to signicantly advance the state of the art for bounded model checking (BMC) and inductive verication (IV) of hybrid discrete-continuous systems. Our approach combines the expertise of partners coming from dierent domains, like hybrid systems modeling and digital circuit...... verication, bounded plan- ning and heuristic search, combinatorial optimization and integer programming. Af- ter sketching the overall verication ow we present rst results indicating that the combination and tight integration of dierent verication engines is a rst step to pave the way to fully automated BMC...

  14. Space-Bounded Church-Turing Thesis and Computational Tractability of Closed Systems.

    Science.gov (United States)

    Braverman, Mark; Schneider, Jonathan; Rojas, Cristóbal

    2015-08-28

    We report a new limitation on the ability of physical systems to perform computation-one that is based on generalizing the notion of memory, or storage space, available to the system to perform the computation. Roughly, we define memory as the maximal amount of information that the evolving system can carry from one instant to the next. We show that memory is a limiting factor in computation even in lieu of any time limitations on the evolving system-such as when considering its equilibrium regime. We call this limitation the space-bounded Church-Turing thesis (SBCT). The SBCT is supported by a simulation assertion (SA), which states that predicting the long-term behavior of bounded-memory systems is computationally tractable. In particular, one corollary of SA is an explicit bound on the computational hardness of the long-term behavior of a discrete-time finite-dimensional dynamical system that is affected by noise. We prove such a bound explicitly.

  15. Effect of bounded noise on chaotic motion of a triple-well potential system

    Energy Technology Data Exchange (ETDEWEB)

    Yang Xiaoli [Department of Applied Mathematics, Northwestern Polytechnic University, Xi' an 710072 (China)]. E-mail: yangxiaoli205@163.com; Xu Wei [Department of Applied Mathematics, Northwestern Polytechnic University, Xi' an 710072 (China)]. E-mail: weixu@nwpu.edu.cn; Sun Zhongkui [Department of Applied Mathematics, Northwestern Polytechnic University, Xi' an 710072 (China); Fang Tong [Department of Applied Mechanics, Northwestern Polytechnic University, Xi' an 710072 (China)

    2005-07-01

    The chaotic behavior of Duffing oscillator possessing both homoclinic and heteroclinic orbits and subjected to harmonic and bounded noise excitations is investigated. By means of the random Melnikov technique together with associated mean-square criterion, necessary conditions for onset of chaos resulting from homoclinic or heteroclinic bifurcation are derived semi-analytically. The results reveal that for larger noise intensity the threshold amplitude of bounded noise for onset of chaos will move upward as the noise intensity increases, which is further verified by the top Lyapunov exponents of the system. Thus the larger the noise intensity results in the less possible chaotic domain in parameter space. The effects of bounded noise on Poincare maps of the system responses are also discussed, together with the numerical simulation of the top Lyapunov exponents.

  16. The bifurcation threshold value of the chaos detection system for a weak signal

    Institute of Scientific and Technical Information of China (English)

    李月; 杨宝俊; 杜立志; 袁野

    2003-01-01

    Recently, it has become an important problem to confirm the bifurcation threshold value of a chaos detection system for a weak signal in the fields of chaos detection. It is directly related to whether the results of chaos detection are correct or not. In this paper, the discrimination system for the dynamic behaviour of a chaos detection system for a weak signal is established by using the theory of linear differential equation with periodic coefficients and computing the Lyapunov exponents of the chaos detection system; and then, the movement state of the chaos detection system is defined. The simulation experiments show that this method can exactly confirm the bifurcation threshold value of the chaos detection system.

  17. Impedance-Based High Frequency Resonance Analysis of DFIG System in Weak Grids

    DEFF Research Database (Denmark)

    Song, Yipeng; Wang, Xiongfei; Blaabjerg, Frede

    2017-01-01

    The impedance-based model of Doubly Fed Induction Generator (DFIG) systems, including the rotor part (Rotor Side Converter (RSC) and induction machine), and the grid part (Grid Side Converter (GSC) and its output filter), has been developed for analysis and mitigation of the Sub- Synchronous...... Resonance (SSR). However, the High Frequency Resonance (HFR) of DFIG systems due to the impedance interaction between DFIG system and parallel compensated weak network is often overlooked. This paper thus investigates the impedance characteristics of DFIG systems for the analysis of HFR. The influences...... of the rotor speed variation, the machine mutual inductance and the digital control delay are evaluated. Two resonances phenomena are revealed, i.e., 1) the series HFR between the DFIG system and weak power grid; 2) the parallel HFR between the rotor part and the grid part of DFIG system. The impedance...

  18. Large time behavior of weakly coupled systems of first-order Hamilton-Jacobi equations

    CERN Document Server

    Camilli, Fabio; Loreti, Paola; Nguyen, Vinh Duc

    2011-01-01

    We show a large time behavior result for class of weakly coupled systems of first-order Hamilton-Jacobi equations in the periodic setting. We use a PDE approach to extend the convergence result proved by Namah and Roquejoffre (1999) in the scalar case. Our proof is based on new comparison, existence and regularity results for systems. An interpretation of the solution of the system in terms of an optimal control problem with switching is given.

  19. Weakly nonlinear dynamics in noncanonical Hamiltonian systems with applications to fluids and plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, P.J., E-mail: morrison@physics.utexas.edu [Department of Physics and Institute for Fusion Studies, University of Texas, Austin (United States); Vanneste, J. [School of Mathematics and Maxwell Institute for Mathematical Sciences, University of Edinburgh (United Kingdom)

    2016-05-15

    A method, called beatification, is presented for rapidly extracting weakly nonlinear Hamiltonian systems that describe the dynamics near equilibria of systems possessing Hamiltonian form in terms of noncanonical Poisson brackets. The procedure applies to systems like fluids and plasmas in terms of Eulerian variables that have such noncanonical Poisson brackets, i.e., brackets with nonstandard and possibly degenerate form. A collection of examples of both finite and infinite dimensions is presented.

  20. Impedance-Based High Frequency Resonance Analysis of DFIG System in Weak Grids

    OpenAIRE

    Song, Yipeng; Wang, Xiongfei; Blaabjerg, Frede

    2017-01-01

    The impedance-based model of Doubly Fed Induction Generator (DFIG) systems, including the rotor part (Rotor Side Converter (RSC) and induction machine), and the grid part (Grid Side Converter (GSC) and its output filter), has been developed for analysis and mitigation of the Sub- Synchronous Resonance (SSR). However, the High Frequency Resonance (HFR) of DFIG systems due to the impedance interaction between DFIG system and parallel compensated weak network is often overlooked. This paper thus...

  1. Global Classical Solutions to Partially Dissipative Quasilinear Hyperbolic Systems with One Weakly Linearly Degenerate Characteristic

    Institute of Scientific and Technical Information of China (English)

    Peng QU; Cunming LIU

    2012-01-01

    For a kind of partially dissipative quasilinear hyperbolic systems without Shizuta-Kawashima condition,in which all the characteristics,except a weakly linearly degenerate one,are involved in the dissipation,the global existence of H2 classical solution to the Cauchy problem with small initial data is obtained.

  2. Global Weak Solutions of Initial Boundary Value Problem for Boltzmann-Poisson System with Absorbing Boundary

    Institute of Scientific and Technical Information of China (English)

    崔国忠; 张志平; 等

    2002-01-01

    This paper deals with the initial boundary value value problem for the Boltzmann-Poisson system ,which arises in semiconductor physics,with absorbing boundary.The global existence of weak solutions is proved by using the stability of velocity averages and the compactness results on L1-theory under weaker conditons on initial boundary values.

  3. Toward quantifying metrics for rail-system resilience : Identification and analysis of performance weak resilience signals

    NARCIS (Netherlands)

    Regt, A. de; Siegel, A.W.; Schraagen, J.M.C.

    2016-01-01

    This paper aims to enhance tangibility of the resilience engineering concept by facilitating understanding and operationalization of weak resilience signals (WRSs) in the rail sector. Within complex socio-technical systems, accidents can be seen as unwanted outcomes emerging from uncontrolled source

  4. Toward quantifying metrics for rail-system resilience : Identification and analysis of performance weak resilience signals

    NARCIS (Netherlands)

    Regt, A. de; Siegel, A.W.; Schraagen, J.M.C.

    2016-01-01

    This paper aims to enhance tangibility of the resilience engineering concept by facilitating understanding and operationalization of weak resilience signals (WRSs) in the rail sector. Within complex socio-technical systems, accidents can be seen as unwanted outcomes emerging from uncontrolled

  5. Weak Links: Stabilizers of Complex Systems from Proteins to Social Networks

    Science.gov (United States)

    Csermely, Peter

    Why do women stabilize our societies? Why can we enjoy and understand Shakespeare? Why are fruitflies uniform? Why do omnivorous eating habits aid our survival? Why is Mona Lisa's smile beautiful? -- Is there any answer to these questions? This book shows that the statement: "weak links stabilize complex systems" holds the answers to all of the surprising questions above. The author (recipientof several distinguished science communication prizes) uses weak (low affinity, low probability) interactions as a thread to introduce a vast varietyof networks from proteins to ecosystems.

  6. The minimal habitat size for spreading in a weak competition system with two free boundaries

    Science.gov (United States)

    Wu, Chang-Hong

    2015-08-01

    In this paper, we focus on the dynamics for a Lotka-Volterra type weak competition system with two free boundaries, where free boundaries which may intersect each other as time evolves are used to describe the spreading of two competing species, respectively. In the weak competition case, the dynamics of this model can be classified into four cases, which forms a spreading-vanishing quartering. The notion of the minimal habitat size for spreading is introduced to determine if species can always spread. Some sufficient conditions for spreading and vanishing are established. Also, when spreading occurs, some rough estimates for spreading speed and the long-time behavior of solutions are established.

  7. Development of Orally Bioavailable Therapeutics by the Chloroplast Expression System to Counter Muscle Degeneration, Weakness, and Fibrosis in DMD

    Science.gov (United States)

    2016-11-01

    Counter Muscle Degeneration, Weakness, and Fibrosis in DMD PRINCIPAL INVESTIGATOR: Elisabeth Barton CONTRACTING ORGANIZATION: University of Florida...Development of Orally Bioavailable Therapeutics by the Chloroplast Expression System to Counter Muscle Degeneration, Weakness, and Fibrosis in DMD 5b...Approved for Public Release; Distribution Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT Patients with DMD suffer from progressive muscle weakness and

  8. Chaotic anti-control for the bounded linear continuous-time system

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    With regard to the bounded linear continuous-time system,a universal chaotic anti-controlling method was presented on the basis of tracking control.A tracking controller is designed to such an extent that it can track any chaotic reference input,thus making it possible to chaotify the linear system.The controller is identical in structure for different controlled linear systems.Computer simulations proved the effectiveness of the proposed method.

  9. Chaotic anti-control for the bounded linear continuous-time system

    Institute of Scientific and Technical Information of China (English)

    Li Jianfen; Lin Hui; Li Nong

    2008-01-01

    With regard to the bounded linear continuous-time system, a universal chaotic anti-controlling method was presented on the basis of tracking control. A tracking controller is designed to such an extent that it can track any chaotic reference input, thus making it possible to chaotify the linear system. The controller is identical in structure for different controlled linear systems. Computer simulations proved the effectiveness of the proposed method.

  10. A k-Bounded Symbolic Execution for Checking Strong Heap Properties of Open Systems

    DEFF Research Database (Denmark)

    Lee, Jooyong; Deng, Xianghua; Bogor, Robby

    2006-01-01

    This paper presents Kiasan, a bounded technique to reason about open systems based on a path sensitive, relatively sound and complete symbolic execution instead of the usual compositional reasoning through weakest precondition calculation that summarizes all execution paths. Kiasan is able to che...

  11. Bounds on relative entropy of entanglement for multi-party systems

    OpenAIRE

    Plenio, M. B.; Vedral, V.

    2000-01-01

    We present upper and lower bounds to the relative entropy of entanglement of multi-party systems in terms of the bi-partite entanglements of formation and distillation and entropies of various subsystems. We point out implications of our results to the local reversible convertibility of multi-party pure states and discuss their physical basis in terms of deleting of information.

  12. Bounds on relative entropy of entanglement for multi-party systems

    Energy Technology Data Exchange (ETDEWEB)

    Plenio, M.B. [Optics Section, Blackett Laboratory, Imperial College, London (United Kingdom); Vedral, V. [Optics Section, Blackett Laboratory, Imperial College, London (United Kingdom); Centre for Quantum Computation, Clarendon Laboratory, University of Oxford, Oxford (United Kingdom)

    2001-09-07

    We present upper and lower bounds to the relative entropy of entanglement of multi-party systems in terms of the bi-partite entanglements of formation and distillation and entropies of various subsystems. We point out implications of our results to the local reversible convertibility of multi-party pure states and discuss their physical basis in terms of deleting information. (author)

  13. Locally Bounded Function Spaces as the External Environment for Nonlinear Systems

    Directory of Open Access Journals (Sweden)

    Valery G. Fetisov

    2013-01-01

    Full Text Available . In this paper we consider locally bounded function spaces that act as the external environment for nonlinear dynamic systems. We give non-traditional examples of above spaces in which the basis of the selected function Orlicz space

  14. Exact lower and upper bounds on stationary moments in stochastic biochemical systems

    Science.gov (United States)

    Ghusinga, Khem Raj; Vargas-Garcia, Cesar A.; Lamperski, Andrew; Singh, Abhyudai

    2017-08-01

    In the stochastic description of biochemical reaction systems, the time evolution of statistical moments for species population counts is described by a linear dynamical system. However, except for some ideal cases (such as zero- and first-order reaction kinetics), the moment dynamics is underdetermined as lower-order moments depend upon higher-order moments. Here, we propose a novel method to find exact lower and upper bounds on stationary moments for a given arbitrary system of biochemical reactions. The method exploits the fact that statistical moments of any positive-valued random variable must satisfy some constraints that are compactly represented through the positive semidefiniteness of moment matrices. Our analysis shows that solving moment equations at steady state in conjunction with constraints on moment matrices provides exact lower and upper bounds on the moments. These results are illustrated by three different examples—the commonly used logistic growth model, stochastic gene expression with auto-regulation and an activator-repressor gene network motif. Interestingly, in all cases the accuracy of the bounds is shown to improve as moment equations are expanded to include higher-order moments. Our results provide avenues for development of approximation methods that provide explicit bounds on moments for nonlinear stochastic systems that are otherwise analytically intractable.

  15. Exact, approximate solutions and error bounds for coupled implicit systems of partial differential equations

    Directory of Open Access Journals (Sweden)

    Lucas Jódar

    1992-01-01

    Full Text Available In this paper coupled implicit initial-boundary value systems of second order partial differential equations are considered. Given a finite domain and an admissible error ϵ an analytic approximate solution whose error is upper bounded by ϵ in the given domain is constructed in terms of the data.

  16. Majorana bound state in a coupled quantum-dot hybrid-nanowire system

    Science.gov (United States)

    Deng, M. T.; Vaitiekėnas, S.; Hansen, E. B.; Danon, J.; Leijnse, M.; Flensberg, K.; Nygård, J.; Krogstrup, P.; Marcus, C. M.

    2016-12-01

    Hybrid nanowires combining semiconductor and superconductor materials appear well suited for the creation, detection, and control of Majorana bound states (MBSs). We demonstrate the emergence of MBSs from coalescing Andreev bound states (ABSs) in a hybrid InAs nanowire with epitaxial Al, using a quantum dot at the end of the nanowire as a spectrometer. Electrostatic gating tuned the nanowire density to a regime of one or a few ABSs. In an applied axial magnetic field, a topological phase emerges in which ABSs move to zero energy and remain there, forming MBSs. We observed hybridization of the MBS with the end-dot bound state, which is in agreement with a numerical model. The ABS/MBS spectra provide parameters that are useful for understanding topological superconductivity in this system.

  17. Current conservation in electrodisintegration of a bound system in the Bethe-Salpeter approach

    CERN Document Server

    Karmanov, V A

    2014-01-01

    Using our solutions of the Bethe-Salpeter equation with OBE kernel in Minkowski space both for the bound and scattering states, we calculate the transition form factors for electrodisintegration of the bound system which determine the electromagnetic current J of this process. Special emphasis is put on verifying the gauge invariance which should manifest itself in the current conservation. We find that for any value of the momentum transfer q the contributions of the plane wave and the final state interaction to the quantity J.q cancel each other thus providing J.q=0. However, this cancellation is obtained only if the initial Bethe-Salpeter amplitude (bound state), the final one (scattering state) and the current operator are strictly consistent with each other. A reliable result for the transition form factor can be found only in this case.

  18. Bounding the Failure Probability Range of Polynomial Systems Subject to P-box Uncertainties

    Science.gov (United States)

    Crespo, Luis G.; Kenny, Sean P.; Giesy, Daniel P.

    2012-01-01

    This paper proposes a reliability analysis framework for systems subject to multiple design requirements that depend polynomially on the uncertainty. Uncertainty is prescribed by probability boxes, also known as p-boxes, whose distribution functions have free or fixed functional forms. An approach based on the Bernstein expansion of polynomials and optimization is proposed. In particular, we search for the elements of a multi-dimensional p-box that minimize (i.e., the best-case) and maximize (i.e., the worst-case) the probability of inner and outer bounding sets of the failure domain. This technique yields intervals that bound the range of failure probabilities. The offset between this bounding interval and the actual failure probability range can be made arbitrarily tight with additional computational effort.

  19. High Frequency Resonance Damping of DFIG based Wind Power System under Weak Network

    DEFF Research Database (Denmark)

    Song, Yipeng; Wang, Xiongfei; Blaabjerg, Frede

    2017-01-01

    When operating in a micro or weak grid which has a relatively large network impedance, the Doubly Fed Induction Generator (DFIG) based wind power generation system is prone to suffer high frequency resonance due to the impedance interaction between DFIG system and the parallel compensated network...... (series RL + shunt C). In order to improve the performance of the DFIG system as well as other units and loads connected to the weak grid, the high frequency resonance needs to be effectively damped. In this paper, the proposed active damping control strategy is able to implement effective damping either...... in the Rotor Side Converter (RSC) or in the Grid Side Converter (GSC), through the introduction of virtual positive capacitor or virtual negative inductor to reshape the DFIG system impedance and mitigate the high frequency resonance. A detailed theoretical explanation on the virtual positive capacitor...

  20. High Frequency Resonance Damping of DFIG based Wind Power System under Weak Network

    DEFF Research Database (Denmark)

    Song, Yipeng; Wang, Xiongfei; Blaabjerg, Frede

    2017-01-01

    When operating in a micro or weak grid which has a relatively large network impedance, the Doubly Fed Induction Generator (DFIG) based wind power generation system is prone to suffer high frequency resonance due to the impedance interaction between DFIG system and the parallel compensated network...... (series RL + shunt C). In order to improve the performance of the DFIG system as well as other units and loads connected to the weak grid, the high frequency resonance needs to be effectively damped. In this paper, the proposed active damping control strategy is able to implement effective damping either...... in the Rotor Side Converter (RSC) or in the Grid Side Converter (GSC), through the introduction of virtual positive capacitor or virtual negative inductor to reshape the DFIG system impedance and mitigate the high frequency resonance. A detailed theoretical explanation on the virtual positive capacitor...

  1. Modulation properties of spatial three-waveguide system using weakly coupled mode theory

    Institute of Scientific and Technical Information of China (English)

    Yiling Sun; Jianxia Pan

    2007-01-01

    Based on the weakly coupled mode theory, the modulation properties of three-waveguide system are analyzed in general. We examine the modulation behavior for two cases that a voltage is applied on the beamlaunched waveguide or non-beam-launched waveguide. The analytical intensity distributions in both cases are given. Applications of the spatial multi-waveguide coupling systems include spatial light modulators,optical switches, optical interconnection, and spatial optical signal processing.

  2. DETECTING TECHNIQUE OF WEAK PERIODIC PULSE SIGNAL VIA SYNTHESIS OF CROSS-CORRELATION AND CHAOTIC SYSTEM

    Institute of Scientific and Technical Information of China (English)

    Li Yue; Yang Baojun; Lu Peng; Li Shizhe

    2003-01-01

    In this letter, with the synthesis of usual cross-correlation detecting method andchaotic detecting method, a new detecting system for the weak periodic pulse signal is constituted,in which the two methods can play respective preponderance. Theoretical analyses and simulationstudies have shown that the detecting system is very sensitive to the periodic pulse signal understrong noise background and has exceedingly powerful capability of suppressing complex noise.

  3. Weak asymptotic solution for a non-strictly hyperbolic system of conservation laws-II

    Directory of Open Access Journals (Sweden)

    Manas Ranjan Sahoo

    2016-04-01

    Full Text Available In this article we introduce a concept of entropy weak asymptotic solution for a system of conservation laws and construct the same for a prolonged system of conservation laws which is highly non-strictly hyperbolic. This is first done for Riemann type initial data by introducing $\\delta,\\delta',\\delta''$ waves along a discontinuity curve and then for general initial data by piecing together the Riemann solutions.

  4. On the bound of the Lyapunov exponents for the fractional differential systems.

    Science.gov (United States)

    Li, Changpin; Gong, Ziqing; Qian, Deliang; Chen, YangQuan

    2010-03-01

    In recent years, fractional(-order) differential equations have attracted increasing interests due to their applications in modeling anomalous diffusion, time dependent materials and processes with long range dependence, allometric scaling laws, and complex networks. Although an autonomous system cannot define a dynamical system in the sense of semigroup because of the memory property determined by the fractional derivative, we can still use the Lyapunov exponents to discuss its dynamical evolution. In this paper, we first define the Lyapunov exponents for fractional differential systems then estimate the bound of the corresponding Lyapunov exponents. For linear fractional differential system, the bounds of its Lyapunov exponents are conveniently derived which can be regarded as an example for the theoretical results established in this paper. Numerical example is also included which supports the theoretical analysis.

  5. Field theory and weak Euler-Lagrange equation for classical particle-field systems.

    Science.gov (United States)

    Qin, Hong; Burby, Joshua W; Davidson, Ronald C

    2014-10-01

    It is commonly believed as a fundamental principle that energy-momentum conservation of a physical system is the result of space-time symmetry. However, for classical particle-field systems, e.g., charged particles interacting through self-consistent electromagnetic or electrostatic fields, such a connection has only been cautiously suggested. It has not been formally established. The difficulty is due to the fact that the dynamics of particles and the electromagnetic fields reside on different manifolds. We show how to overcome this difficulty and establish the connection by generalizing the Euler-Lagrange equation, the central component of a field theory, to a so-called weak form. The weak Euler-Lagrange equation induces a new type of flux, called the weak Euler-Lagrange current, which enters conservation laws. Using field theory together with the weak Euler-Lagrange equation developed here, energy-momentum conservation laws that are difficult to find otherwise can be systematically derived from the underlying space-time symmetry.

  6. Design on the Time-domain Airborne Electromagnetic Weak Signal Data Acquisition System

    Directory of Open Access Journals (Sweden)

    Yong Guo

    2013-07-01

    Full Text Available According to principle of transient electromagnetic method as well as its signal characteristics, this paper designed and implemented a time-domain airborne electromagnetic weak signal data acquisition system. With the use of the floating-point amplification technology, the system amplifies the weak transient electromagnetic signal dynamically. CPLD and DSP were used as the decoding control circuit and the main controller for processing the sampled data, respectively. The transient electromagnetic signal acquisition system, which was designed with a dynamic range up to 144dB and a sampling rate up to 100 kHz, meets the requirements of the high sampling rate with high precision and it has been applied in the time-domain fixed-wing airborne electromagnetic mineral exploration.

  7. Collective dynamics of multimode bosonic systems induced by weak quantum measurement

    CERN Document Server

    Mazzucchi, Gabriel; Caballero-Benitez, Santiago F; Mekhov, Igor B

    2016-01-01

    In contrast to strong projective measurement, which freezes the system evolution by quantum Zeno effect, weak measurement can effectively compete with standard unitary dynamics leading to nontrivial effects. Here we consider global weak measurement addressing several bosonic modes at the same time, thus preserving quantum superpositions due to the lack of which path information. While for certainty we focus on ultracold atoms, the idea can be generalized to other multimode quantum systems, including various quantum emitters, optomechanical arrays, and purely photonic systems with multiple-path interferometers. We show that light scattering from ultracold bosons in optical lattices can be used for defining macroscopically occupied spatial modes that exhibit long-range coherent dynamics. Even for constant external measurement, the quantum measurement backaction acts on the atomic ensemble quasi-periodically and induces collective oscillatory dynamics of all the atoms. We introduce an effective model for the evo...

  8. Exact Pointer Properties for Quantum System Projector Measurements with Application to Weak Measurements and Their Accuracy

    CERN Document Server

    Parks, A D

    2010-01-01

    Exact pointer states are obtained for projection operator measurements performed upon pre-selected (PS) and upon pre- and post-selected (PPS) quantum systems. These states are used to provide simple exact expressions for both the pointer spatial probability distribution profiles and the mean values of arbitrary pointer observables associated with PS and PPS projection operator measurements that are valid for any strength of the interaction which couples a measurement pointer to the quantum system. These profiles and mean values are compared in order to identify the effects of post-selection upon projector measurement pointers. As a special case, these mean value results are applied to the weak measurement regime - yielding PS and PPS mean value expressions which are valid for any operator (projector or non-projector). Measurement sensitivities which are useful for estimating weak measurement accuracies for PS and PPS systems are also obtained and discussed.

  9. Exponentially small splitting for whiskered tori in Hamiltonian systems: Flow-box coordinates and upper bounds

    CERN Document Server

    Delshams, A; Seara, T M

    2003-01-01

    We consider a singular or weakly hyperbolic Hamiltonian, with $n+1$ degrees of freedom, as a model for the behaviour of a nearly-integrable Hamiltonian near a simple resonance. The model consists of an integrable Hamiltonian possessing an $n$-dimensional hyperbolic invariant torus with fast frequencies $\\omega/\\sqrt\\varepsilon$ and coincident whiskers, plus a perturbation of order $\\mu=\\varepsilon^p$. The vector $\\omega$ is assumed to satisfy a Diophantine condition. We provide a tool to study, in this singular case, the splitting of the perturbed whiskers for $\\varepsilon$ small enough, as well as their homoclinic intersections, using the Poincar\\'e--Melnikov method. Due to the exponential smallness of the Melnikov function, the size of the error term has to be carefully controlled. So we introduce flow-box coordinates in order to take advantage of the quasiperiodicity properties of the splitting. As a direct application of this approach, we obtain quite general upper bounds for the splitting.

  10. Exponentially small splitting for whiskered tori in Hamiltonian systems Flow-box coordinates and upper bounds

    CERN Document Server

    Delshams, A

    2003-01-01

    We consider a singular or weakly hyperbolic Hamiltonian, with $n+1$ degrees of freedom, as a model for the behaviour of a nearly-integrable Hamiltonian near a simple resonance. The model consists of an integrable Hamiltonian possessing an $n$-dimensional hyperbolic invariant torus with fast frequencies $\\omega/\\sqrt\\varepsilon$ and coincident whiskers, plus a perturbation of order $\\mu=\\varepsilon^p$. The vector $\\omega$ is assumed to satisfy a Diophantine condition. We provide a tool to study, in this singular case, the splitting of the perturbed whiskers for $\\varepsilon$ small enough, as well as their homoclinic intersections, using the Poincar\\'e--Melnikov method. Due to the exponential smallness of the Melnikov function, the size of the error term has to be carefully controlled. So we introduce flow-box coordinates in order to take advantage of the quasiperiodicity properties of the splitting. As a direct application of this approach, we obtain quite general upper bounds for the splitting.

  11. Predicting the bounds of large chaotic systems using low-dimensional manifolds.

    Science.gov (United States)

    Haugaard, Asger M

    2017-01-01

    Predicting extrema of chaotic systems in high-dimensional phase space remains a challenge. Methods, which give extrema that are valid in the long term, have thus far been restricted to models of only a few variables. Here, a method is presented which treats extrema of chaotic systems as belonging to discretised manifolds of low dimension (low-D) embedded in high-dimensional (high-D) phase space. As a central feature, the method exploits that strange attractor dimension is generally much smaller than parent system phase space dimension. This is important, since the computational cost associated with discretised manifolds depends exponentially on their dimension. Thus, systems that would otherwise be associated with tremendous computational challenges, can be tackled on a laptop. As a test, bounding manifolds are calculated for high-D modifications of the canonical Duffing system. Parameters can be set such that the bounding manifold displays harmonic behaviour even if the underlying system is chaotic. Thus, solving for one post-transient forcing cycle of the bounding manifold predicts the extrema of the underlying chaotic problem indefinitely.

  12. Phase reduction of weakly perturbed limit cycle oscillations in time-delay systems

    Science.gov (United States)

    Novičenko, V.; Pyragas, K.

    2012-06-01

    The phase reduction method is applied to a general class of weakly perturbed time-delay systems exhibiting periodic oscillations. The adjoint equation with an appropriate initial condition for the infinitesimal phase response curve of a time-delay system is derived. The method is demonstrated numerically for the Mackey-Glass equation as well as for a chaotic Rössler system subject to a delayed feedback control (DFC). We show that the profile of the phase response curve of a periodic orbit stabilized by the DFC algorithm does not depend on the control matrix. This property is universal and holds for any dynamical system subject to the DFC.

  13. Continuous Dep endence of Bounded Φ-variation Solutions on Parameter for a Class of Discontinuous Systems

    Institute of Scientific and Technical Information of China (English)

    MA Xue-min; LI Bao-lin; LIN Chang-wei

    2015-01-01

    The functions of bounded Φ-variation are development and generalization of bounded variation functions in the usual sense.Henstock-Kurzweil integral is a very useful tool for some discontinuous systems. In this paper, by using Henstock-Kurzweil integral, we establish theorems of continuous dependence of bounded Φ-variation solutions on parameter for a class of discontinuous systems on the base of Φ-function. These results are essential generalizations of continuous dependence of bounded variation solutions on parameter for the systems.

  14. Quantum metrology in open systems: dissipative Cramér-Rao bound.

    Science.gov (United States)

    Alipour, S; Mehboudi, M; Rezakhani, A T

    2014-03-28

    Estimation of parameters is a pivotal task throughout science and technology. The quantum Cramér-Rao bound provides a fundamental limit of precision allowed to be achieved under quantum theory. For closed quantum systems, it has been shown how the estimation precision depends on the underlying dynamics. Here, we propose a general formulation for metrology scenarios in open quantum systems, aiming to relate the precision more directly to properties of the underlying dynamics. This feature may be employed to enhance an estimation precision, e.g., by quantum control techniques. Specifically, we derive a Cramér-Rao bound for a fairly large class of open system dynamics, which is governed by a (time-dependent) dynamical semigroup map. We illustrate the utility of this scenario through three examples.

  15. Analytical Solution of Relativistic Few-Body Bound Systems with a Generalized Yukawa Potential

    Science.gov (United States)

    Aslanzadeh, M.; Rajabi, A. A.

    2016-03-01

    We have investigated in this paper the few-body bound systems in a simple semi-relativistic scheme. For this aim, we introduced a spin independent relativistic description for a few-identical body system by presenting the analytical solution of few-particle Klein-Gordon equation. Performing calculations in D-dimensional configuration on the basis of the hypercentral approach, we reduced the few-body Klein-Gordon equation to a Schrödinger-like form. This equation is solved by using the Nikiforov-Uvarov method, through which the energy equations and eigenfunctions for a few-body bound system are obtained. We used the spin- and isospin-independent generalized Yukawa potential in our calculations, and the dependence of the few-body binding energies on the potential parameters has been investigated.

  16. Adaptive Fuzzy Bounded Control for Consensus of Multiple Strict-Feedback Nonlinear Systems.

    Science.gov (United States)

    Wang, Wei; Tong, Shaocheng

    2017-01-10

    This paper studies the adaptive fuzzy bounded control problem for leader-follower multiagent systems, where each follower is modeled by the uncertain nonlinear strict-feedback system. Combining the fuzzy approximation with the dynamic surface control, an adaptive fuzzy control scheme is developed to guarantee the output consensus of all agents under directed communication topologies. Different from the existing results, the bounds of the control inputs are known as a priori, and they can be determined by the feedback control gains. To realize smooth and fast learning, a predictor is introduced to estimate each error surface, and the corresponding predictor error is employed to learn the optimal fuzzy parameter vector. It is proved that the developed adaptive fuzzy control scheme guarantees the uniformly ultimate boundedness of the closed-loop systems, and the tracking error converges to a small neighborhood of the origin. The simulation results and comparisons are provided to show the validity of the control strategy presented in this paper.

  17. Direct Shear Mapping: Prospects for weak lensing studies of individual galaxy-galaxy lensing systems

    CERN Document Server

    de Burgh-Day, Catherine O; Webster, Rachel L; Hopkins, Andrew M

    2015-01-01

    We have investigated, using both a theoretical and an empirical approach, the frequency of low redshift galaxy-galaxy lensing systems in which the signature of weak lensing might be directly detectable. We find good agreement between these two approaches. In order to make a theoretical estimate of the weak lensing shear, $\\gamma$, for each galaxy in a catalogue, we have made an estimate of the asymptotic circular velocity from the stellar mass using three different approaches: from a simulation based relation, from an empirically-derived relation, and using the baryonic Tully-Fisher relation. Using data from the Galaxy and Mass Assembly redshift survey we estimate the frequency of detectable weak lensing at low redshift. We find that to a redshift of $z\\sim 0.6$, the probability of a galaxy being weakly lensed by at least $\\gamma = 0.02$ is $\\sim 0.01$. A scatter in the $M_*-M_h$ relation results in a shift towards higher measured shears for a given population of galaxies. Given this, and the good probability...

  18. Weak Serializable Concurrency Control in Distributed Real-Time Database Systems

    Institute of Scientific and Technical Information of China (English)

    党德鹏; 刘云生; 等

    2002-01-01

    Most of the proposed concurrency control protocols for real-time database systems are based on serializability theorem.Owing to the unique characteristics of real-time database applications and the importance of satisfying the timing constraints of transactions,serializability is too strong as a correctness criterion and not suitable for real-time databases in most cases.On the other hand,relaxed serializability including epsilon-serializability and similarity-serializability can allow more real-time transactions to satisfy their timing constraints,but database consistency may be sacrificed to some extent.We thus propose the use of weak serializability(WSR)that is more relaxed than conflicting serializability while database consistency is maintained.In this paper,we first formally define the new notion of correctness called weak serializability.After the necessary and sufficient conditions for weak serializability are shown,corresponding concurrency control protocol WDHP(weak serializable distributed high prority protocol)is outlined for distributed real time databases,where a new lock mode called mask lock mode is proposed for simplifying the condition of global consistency.Finally,through a series of simulation studies,it is shown that using the new concurrency control protocol the performance of distributed realtime databases can be greatly improved.

  19. Autonomous Rubidium Clock Weak Frequency Jump Detector for Onboard Navigation Satellite System.

    Science.gov (United States)

    Khare, Akshay; Arora, Rajat; Banik, Alak; Mehta, Sanjay D

    2016-02-01

    Frequency jumps are common in rubidium frequency sources. They affect the estimation of user position in navigational satellite systems. These jumps must be detected and corrected immediately as they have direct impact on the navigation system integrity. A novel weak frequency jump detector is proposed based on a Kalman filter with a multi-interval approach. This detector can be applied for both "sudden" and "slow" frequency transitions. In this detection method, noises of clock data are reduced by Kalman filtering, for accurate estimation of jump size with less latency. Analysis on in-orbit rubidium atomic frequency standard (RAFS) phase telemetry data shows that the detector can be used for fast detection and correction of weak frequency jumps. Furthermore, performance comparison of different existing frequency jump detection techniques with the proposed detector is discussed. A multialgorithm-based strategy is proposed depending on the jump size and latency for onboard navigation satellites having RAFS as the primary frequency source.

  20. ROBUST KALMAN FILTERING FOR SYSTEMS UNDER NORM BOUNDED UNCERTAINTIES IN ALL SYSTEM MATRICES AND ERROR COVARIANCE CONSTRAINTS

    Institute of Scientific and Technical Information of China (English)

    XIA Yuanqing; HAN Jingqing

    2005-01-01

    This paper concerns robust Kalman filtering for systems under norm bounded uncertainties in all the system matrices and error covariance constraints. Sufficient conditions are given for the existence of such filters in terms of Riccati equations. The solutions to the conditions can be used to design the filters. Finally, an illustrative example is given to demonstrate the effectiveness of the proposed design procedure.

  1. Fractionated plasma separation and adsorption system: a novel system for blood purification to remove albumin bound substances.

    Science.gov (United States)

    Falkenhagen, D; Strobl, W; Vogt, G; Schrefl, A; Linsberger, I; Gerner, F J; Schoenhofen, M

    1999-01-01

    The removal of albumin bound substances has gained increasing interest in different diseases, especially in acute and chronic liver disease. Therefore, a new system, the fractionated plasma separation and adsorption (FPSA) system, was developed based on combined membrane and adsorbent blood purification techniques. The most important contribution to the FPSA system was the development of a new polysulfone hollow-fiber filter, which is characterized by a sieving coefficient of 0.89 for human serum albumin (HSA) but only of 0.17 for fibrinogen, and 0 (zero) for IgM immunoglobulins. Using a closed filtrate circuit connected to the new polysulfone filter which integrates 1 or 2 adsorption columns and also a high flux dialyzer adapted to a dialysis machine, the FPSA system opens excellent possibilities for the relatively specific removal of albumin bound substances from the blood such as albumin bound bilirubin or even tryptophan. In comparison to other systems (for example, the Molecular Adsorbent Recirculating System [MARS] and albumin dialysis systems), the FPSA system enables much higher elimination of strongly bound albumin substances. The first clinical investigations have recently started based on a modified dialysis machine designed with all necessary safety measures.

  2. Weak-Coupling Theory for Low-Frequency Periodically Driven Two-Level Systems

    Institute of Scientific and Technical Information of China (English)

    CHEN Ai-Xi; HUANG Ke-Lin; WANG Zhi-Ping

    2008-01-01

    We generalize the Wu-Yang strong-coupling theory to solve analytically periodically driven two-level systems in the weak-coupling and low-frequency regimes for single- and multi-period periodic driving of continuous-wave-type and pulse-type including ultrashort pulses of a few cycles. We also derive a general formula of the AC Stark shift suitable for such diverse situations.

  3. Weakly Nonlinear Theory of Pattern-Forming Systems with Spontaneously Broken Isotropy

    CERN Document Server

    Rossberg, A G; Kramer, L; Pesch, W

    1996-01-01

    Quasi two-dimensional pattern forming systems with spontaneously broken isotropy represent a novel symmetry class, that is experimentally accessible in electroconvection of homeotropically aligned liquid crystals. We present a weakly nonlinear analysis leading to amplitude equations which couple the short-wavelength patterning mode with the Goldstone mode resulting from the broken isotropy. The new coefficients in these equations are calculated from the hydrodynamics. Simulations exhibit a new type of spatio-temporal chaos at onset. The results are compared with experiments.

  4. Global existence of weak solution to the heat and moisture transport system in fibrous porous media

    CERN Document Server

    Li, Buyang; Wang, Yi

    2009-01-01

    This paper is concerned with theoretical analysis of a heat and moisture transfer model arising from textile industries, which is described by a degenerate and strongly coupled parabolic system. We prove the global (in time) existence of weak solution by constructing an approximate solution with some standard smoothing. The proof is based on the physcial nature of gas convection, in which the heat (energy) flux in convection is determined by the mass (vapor) flux in convection.

  5. A New Numerical Method of Determining Parameter Stability Bounds : SISO Linear System with Time-Varying Uncertainties Case

    Energy Technology Data Exchange (ETDEWEB)

    Kang, H.J. [Mando Machinery Co., Pyungtaek (Korea); Ko, J.W. [Yuhan College, Buchon (Korea); Park, M.N. [Yonsei University, Seoul (Korea)

    1999-06-01

    This note presents an efficient numerical method of determining a quadratic stability bound for SISO linear system with time-varying uncertainties. Based on the quadratic stability condition in Linear Matrix Inequalities (LMI) form, the proposed method gives a quadratic stability bound for each system parameter. As an example, the state feedback regulation problem is presented. (author). 12 refs.

  6. Sustainable Innovation in Network-Bound Systems: Implications for the Consumption of Water, Waste Water and Electricity Services

    NARCIS (Netherlands)

    Vliet, van B.J.M.

    2012-01-01

    Network-bound systems are crucial in environmental governance as the usage of their services embody significant environmental impacts. Conditions for network-bound systems providing services to consumers have altered dramatically over the last decades. Liberalization and privatization have led to a

  7. Sustainable Innovation in Network-Bound Systems: Implications for the Consumption of Water, Waste Water and Electricity Services

    NARCIS (Netherlands)

    Vliet, van B.J.M.

    2012-01-01

    Network-bound systems are crucial in environmental governance as the usage of their services embody significant environmental impacts. Conditions for network-bound systems providing services to consumers have altered dramatically over the last decades. Liberalization and privatization have led to a

  8. Response bounds for complex systems with a localised and uncertain nonlinearity

    Science.gov (United States)

    Butlin, T.

    2016-12-01

    Predicting the vibration response of complex nonlinear structures is a significant challenge: the response may involve many modes of the structure; nonlinearity precludes the use of efficient techniques developed for linear systems; and there is often uncertainty associated with the nonlinear law, even to the extent that its functional form is not always known. This paper builds on a recently developed method for handling this class of problem in a novel way. The method exploits the fact that nonlinearities are often spatially localised, and seeks the best- and worst-case system response with respect to a chosen metric by regarding the internal nonlinear force as an independent excitation to the underlying linear system. Constraints are used to capture what is thought to be known about the nonlinearity without needing to specify a particular law. This paper focuses on the case of systems with a single point nonlinearity but with arbitrarily complex underlying linear dynamics, driven by a sinusoidal force excitation. Semi-analytic upper and lower bounds are proposed for root-mean-square response metrics subject to constraints which specify that the nonlinearity should be a combination of (A) passive, (B) displacement-limited, and / or (C) force-saturating. The concept of 'equivalent linear bounds' is also introduced for cases where the response metric is thought to be dominated by the same frequency as the input. The bounds corresponding to a passive and displacement-limited nonlinearity are compared with Monte Carlo experimental and numerical results from an impacting beam test rig. The bounds corresponding to a passive and force-saturating nonlinearity are compared with numerical results for a friction-damped beam. The global upper and lower bounds are satisfied for all input frequencies but are generally found to be rather conservative. The 'equivalent linear bounds' show remarkably good agreement for predicting the range of root-mean-square velocity responses

  9. Finding the exact delay bound for consensus of linear multi-agent systems

    Science.gov (United States)

    Cepeda-Gomez, Rudy

    2016-08-01

    This paper focuses on consensus problems for high-order, linear multi-agent systems. Undirected communication topologies along with a fixed and uniform communication time delay are taken into account. This class of problems has been widely studied in the literature, but there are still gaps concerning the exact stability bounds in the domain of the delays. The novelty of this paper lies in the determination of an exact and explicit delay bound for consensus. This is done in a very efficient manner by using the cluster treatment of characteristic roots (CTCR) paradigm. Before the stability analysis, a state transformation is performed to decouple the system and simplify the problem. CTCR is then deployed to the individual subsystems to obtain the stability margin in the domain of the delays without the conservatism introduced by other approaches more frequently found in the literature. Simulation results are presented to support the analytical claims.

  10. Frequency Weighted Model Order Reduction Technique and Error Bounds for Discrete Time Systems

    Directory of Open Access Journals (Sweden)

    Muhammad Imran

    2014-01-01

    for whole frequency range. However, certain applications (like controller reduction require frequency weighted approximation, which introduce the concept of using frequency weights in model reduction techniques. Limitations of some existing frequency weighted model reduction techniques include lack of stability of reduced order models (for two sided weighting case and frequency response error bounds. A new frequency weighted technique for balanced model reduction for discrete time systems is proposed. The proposed technique guarantees stable reduced order models even for the case when two sided weightings are present. Efficient technique for frequency weighted Gramians is also proposed. Results are compared with other existing frequency weighted model reduction techniques for discrete time systems. Moreover, the proposed technique yields frequency response error bounds.

  11. Strengths, weaknesses, opportunities and threats of the pig health monitoring systems used in England.

    Science.gov (United States)

    Stärk, K D C; Nevel, A

    2009-10-17

    Several systems are being used in England to record information about the health of pigs. The British Pig Health Scheme (BPHS), the National Animal Disease Information System (NADIS), the Zoonoses Action Plan (ZAP) for Salmonella and the Veterinary Investigation Diagnosis Analysis (VIDA) system have been assessed to make recommendations for their future separate or joint development. The structure, organisation, processes, data quality, dissemination, utilisation and acceptance of each system have been assessed. Information was extracted from documents and websites, and informal interviews were conducted with technical experts and stakeholders. The systems covered a broad range of objectives, used variable approaches and operated at very different scales and budgets. There was a high level of awareness and involvement by the industry. Common weaknesses of the systems were the lack of in-depth quantitative analysis of the data, the lack of assessment of each system's impact, and the unknown level of bias as a result of the voluntary or selective participation in them.

  12. Finite time blow-up for a reaction-diffusion system in bounded domain

    Science.gov (United States)

    Bai, Xueli

    2014-02-01

    This paper mainly considers the coupled parabolic system in a bounded domain: u t = Δ u + u α v p , v t = Δ v + u q v β in Ω × (0, T) with null Dirichlet boundary value condition which had been discussed by Wang in (Z Angew Math Phys 51:160-167, 2000). The aim of this paper is to solve the open problem mentioned in the Remark of Wang (Z Angew Math Phys 51:160-167, 2000).

  13. Consensus seeking in multiagent cooperative control systems with bounded control input

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Consensus algorithms in multiagent cooperative control systems with bounded control input are studied in this paper.Consensus algorithms are considered for the single-integrator dynamics and double-integrator dynamics under different communication interaction topologies,and show that consensus is reached asymptotically using the algorithm proposed in this paper for the single-integrator dynamics if the undirected interaction graph is connected,and consensus is reached asymptotically if the directed interact...

  14. A bound system in the expanding universe with modified holographic Ricci dark energy and dark matter

    CERN Document Server

    Li, En-Kun; Geng, Jin-Ling; Duan, Peng-Fei

    2015-01-01

    The evolution of a bound system in the expanding background has been investigated in this paper. The background is described by a FRW universe with the modified holographic dark energy model, whose equation of state parameter changes with time and can cross the phantom boundary. To study the evolution of the bound system, an interpolating metric is considered, and on this basis the geodesics of a test particle are given. The equation of motion and the effective potential are also derived from the geodesics. By studying the the effective potential and the evolution of the radius of a test particle in the bound system of the Milky Way galaxy, we have found that the galaxy would go through three stages: expands from a singular point; stays in a discoid for a period of time; big rip in the future. With the help of analysing the critical angular momentum, we find that the test particle needs less angular momentum to escape from the center mass as time passes.

  15. Bounds on the entropy generated when timing information is extracted from microscopic systems

    CERN Document Server

    Janzing, D; Janzing, Dominik; Beth, Thomas

    2003-01-01

    We consider Hamiltonian quantum systems with energy bandwidth \\Delta E and show that each measurement that determines the time up to an error \\Delta t generates at least the entropy (\\hbar/(\\Delta t \\Delta E))^2/2. Our result describes quantitatively to what extent all timing information is quantum information in systems with limited energy. It provides a lower bound on the dissipated energy when timing information of microscopic systems is converted to classical information. This is relevant for low power computation since it shows the amount of heat generated whenever a band limited signal controls a classical bit switch. Our result provides a general bound on the information-disturbance trade-off for von-Neumann measurements that distinguish states on the orbits of continuous unitary one-parameter groups with bounded spectrum. In contrast, information gain without disturbance is possible for some completely positive semi-groups. This shows that readout of timing information can be possible without entropy ...

  16. Pre-impact fall detection system using dynamic threshold and 3D bounding box

    Science.gov (United States)

    Otanasap, Nuth; Boonbrahm, Poonpong

    2017-02-01

    Fall prevention and detection system have to subjugate many challenges in order to develop an efficient those system. Some of the difficult problems are obtrusion, occlusion and overlay in vision based system. Other associated issues are privacy, cost, noise, computation complexity and definition of threshold values. Estimating human motion using vision based usually involves with partial overlay, caused either by direction of view point between objects or body parts and camera, and these issues have to be taken into consideration. This paper proposes the use of dynamic threshold based and bounding box posture analysis method with multiple Kinect cameras setting for human posture analysis and fall detection. The proposed work only uses two Kinect cameras for acquiring distributed values and differentiating activities between normal and falls. If the peak value of head velocity is greater than the dynamic threshold value, bounding box posture analysis will be used to confirm fall occurrence. Furthermore, information captured by multiple Kinect placed in right angle will address the skeleton overlay problem due to single Kinect. This work contributes on the fusion of multiple Kinect based skeletons, based on dynamic threshold and bounding box posture analysis which is the only research work reported so far.

  17. Improved upper bounds on Kaluza-Klein gravity with current Solar System experiments and observations

    CERN Document Server

    Deng, Xue-Mei

    2015-01-01

    As an extension of previous works on classical tests of Kaluza-Klein (KK) gravity and as an attempt to find more stringent constraints on this theory, its effects on physical experiments and astronomical observations conducted in the Solar System are studied. We investigate the gravitational time delay at inferior conjunction caused by KK gravity, and use new Solar System ephemerides and the observation of \\textit{Cassini} to strengthen constraints on KK gravity by up to two orders of magnitude. These improved upper bounds mean that the fifth-dimensional space in the soliton case is a very flat extra dimension in the Solar System, even in the vicinity of the Sun.

  18. Improved upper bounds on Kaluza-Klein gravity with current Solar System experiments and observations

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Xue-Mei [Chinese Academy of Sciences, Purple Mountain Observatory, Nanjing (China); Xie, Yi [Nanjing University, School of Astronomy and Space Science, Nanjing (China); Shanghai Key Laboratory of Space Navigation and Position Techniques, Shanghai (China); Nanjing University, Ministry of Education, Key Laboratory of Modern Astronomy and Astrophysics, Nanjing (China)

    2015-11-15

    As an extension of previous works on classical tests of Kaluza-Klein (KK) gravity and as an attempt to find more stringent constraints on this theory, its effects on physical experiments and astronomical observations conducted in the Solar System are studied. We investigate the gravitational time delay at inferior conjunction caused by KK gravity, and use new Solar System ephemerides and the observation of Cassini to strengthen constraints on KK gravity by up to two orders of magnitude. These improved upper bounds mean that the fifth-dimensional space in the soliton case is a very flat extra dimension in the Solar System, even in the vicinity of the Sun. (orig.)

  19. Finite Energy and Bounded Actuator Attacks on Cyber-Physical Systems

    Energy Technology Data Exchange (ETDEWEB)

    Djouadi, Seddik M [ORNL; Melin, Alexander M [ORNL; Ferragut, Erik M [ORNL; Laska, Jason A [ORNL; Dong, Jin [ORNL; Drira, Anis [ORNL

    2015-01-01

    As control system networks are being connected to enterprise level networks for remote monitoring, operation, and system-wide performance optimization, these same connections are providing vulnerabilities that can be exploited by malicious actors for attack, financial gain, and theft of intellectual property. Much effort in cyber-physical system (CPS) protection has focused on protecting the borders of the system through traditional information security techniques. Less effort has been applied to the protection of cyber-physical systems from intelligent attacks launched after an attacker has defeated the information security protections to gain access to the control system. In this paper, attacks on actuator signals are analyzed from a system theoretic context. The threat surface is classified into finite energy and bounded attacks. These two broad classes encompass a large range of potential attacks. The effect of theses attacks on a linear quadratic (LQ) control are analyzed, and the optimal actuator attacks for both finite and infinite horizon LQ control are derived, therefore the worst case attack signals are obtained. The closed-loop system under the optimal attack signals is given and a numerical example illustrating the effect of an optimal bounded attack is provided.

  20. Communication: HK propagator uniformized along a one-dimensional manifold in weakly anharmonic systems

    Energy Technology Data Exchange (ETDEWEB)

    Kocia, Lucas, E-mail: lkocia@fas.harvard.edu; Heller, Eric J. [Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138 (United States)

    2014-11-14

    A simplification of the Heller-Herman-Kluk-Kay (HK) propagator is presented that does not suffer from the need for an increasing number of trajectories with dimensions of the system under study. This is accomplished by replacing HK’s uniformizing integral over all of phase space by a one-dimensional curve that is appropriately selected to lie along the fastest growing manifold of a defining trajectory. It is shown that this modification leads to eigenspectra of quantum states in weakly anharmonic systems that can outperform the comparatively computationally cheap thawed Gaussian approximation method and frequently approach the accuracy of spectra obtained with the full HK propagator.

  1. Communication: HK propagator uniformized along a one-dimensional manifold in weakly anharmonic systems

    Science.gov (United States)

    Kocia, Lucas; Heller, Eric J.

    2014-11-01

    A simplification of the Heller-Herman-Kluk-Kay (HK) propagator is presented that does not suffer from the need for an increasing number of trajectories with dimensions of the system under study. This is accomplished by replacing HK's uniformizing integral over all of phase space by a one-dimensional curve that is appropriately selected to lie along the fastest growing manifold of a defining trajectory. It is shown that this modification leads to eigenspectra of quantum states in weakly anharmonic systems that can outperform the comparatively computationally cheap thawed Gaussian approximation method and frequently approach the accuracy of spectra obtained with the full HK propagator.

  2. Field theory and weak Euler-Lagrange equation for classical particle-field systems

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Hong [PPPL; Burby, Joshua W [PPPL; Davidson, Ronald C [PPPL

    2014-10-01

    It is commonly believed that energy-momentum conservation is the result of space-time symmetry. However, for classical particle-field systems, e.g., Klimontovich-Maxwell and Klimontovich- Poisson systems, such a connection hasn't been formally established. The difficulty is due to the fact that particles and the electromagnetic fields reside on different manifolds. To establish the connection, the standard Euler-Lagrange equation needs to be generalized to a weak form. Using this technique, energy-momentum conservation laws that are difficult to find otherwise can be systematically derived.

  3. Integrability of Liénard systems with a weak saddle

    Science.gov (United States)

    Gasull, Armengol; Giné, Jaume

    2017-02-01

    We characterize the local analytic integrability of weak saddles for complex Liénard systems, dot{x}=y-F(x), dot{y}= ax, 0≠ ain C, with F analytic at 0 and F(0)=F'(0)=0. We prove that they are locally integrable at the origin if and only if F( x) is an even function. This result implies the well-known characterization of the centers for real Liénard systems. Our proof is based on finding the obstructions for the existence of a formal integral at the complex saddle, by computing the so-called resonant saddle quantities.

  4. Non-thermal fixed points. Effective weak-coupling for strongly correlated systems far from equilibrium

    Energy Technology Data Exchange (ETDEWEB)

    Berges, J. [Technische Hochschule Darmstadt (Germany). Inst. fuer Kernphysik]|[California Univ., Santa Barbara, CA (United States). Inst. for Theoretical Physics; Rothkopf, A. [Tokyo Univ. (Japan). Dept. of Physics; Schmidt, J. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2008-02-15

    Strongly correlated systems far from equilibrium can exhibit scaling solutions with a dynamically generated weak coupling. We show this by investigating isolated systems described by relativistic quantum field theories for initial conditions leading to nonequilibrium instabilities, such as parametric resonance or spinodal decomposition. The non-thermal fixed points prevent fast thermalization if classical-statistical fluctuations dominate over quantum fluctuations. We comment on the possible significance of these results for the heating of the early universe after inflation and the question of fast thermalization in heavy-ion collision experiments. (orig.)

  5. Distributed acoustic sensing system using an identical weak fiber Bragg grating array

    Science.gov (United States)

    Liu, Sheng; Han, Xinying; Wen, Hongqiao

    2016-10-01

    We propose and experimentally demonstrate a distributed acoustic sensing system using an identical weak fiber Bragg grating array. Phase, frequency and location information of vibration can be demodulated by using a path-match interferometry method. 3×3 coupler demodulation technique is employed to eliminate signal fading in interferometer. Experiments on detecting acoustic wave generated by PZT show that the system is capable of measuring vibrations of up to 1000 Hz over 1.6 km with 2.5m spatial resolution.

  6. Energy Optimization for a Weak Hybrid Power System of an Automobile Exhaust Thermoelectric Generator

    Science.gov (United States)

    Fang, Wei; Quan, Shuhai; Xie, Changjun; Tang, Xinfeng; Ran, Bin; Jiao, Yatian

    2017-07-01

    An integrated starter generator (ISG)-type hybrid electric vehicle (HEV) scheme is proposed based on the automobile exhaust thermoelectric generator (AETEG). An eddy current dynamometer is used to simulate the vehicle's dynamic cycle. A weak ISG hybrid bench test system is constructed to test the 48 V output from the power supply system, which is based on engine exhaust-based heat power generation. The thermoelectric power generation-based system must ultimately be tested when integrated into the ISG weak hybrid mixed power system. The test process is divided into two steps: comprehensive simulation and vehicle-based testing. The system's dynamic process is simulated for both conventional and thermoelectric powers, and the dynamic running process comprises four stages: starting, acceleration, cruising and braking. The quantity of fuel available and battery pack energy, which are used as target vehicle energy functions for comparison with conventional systems, are simplified into a single energy target function, and the battery pack's output current is used as the control variable in the thermoelectric hybrid energy optimization model. The system's optimal battery pack output current function is resolved when its dynamic operating process is considered as part of the hybrid thermoelectric power generation system. In the experiments, the system bench is tested using conventional power and hybrid thermoelectric power for the four dynamic operation stages. The optimal battery pack curve is calculated by functional analysis. In the vehicle, a power control unit is used to control the battery pack's output current and minimize energy consumption. Data analysis shows that the fuel economy of the hybrid power system under European Driving Cycle conditions is improved by 14.7% when compared with conventional systems.

  7. Bounding box framework for efficient phase field simulation of grain growth in anisotropic systems

    CERN Document Server

    Vanherpe, L; Blanpain, B; Vandewalle, S

    2011-01-01

    A sparse bounding box algorithm is extended to perform efficient phase field simulations of grain growth in anisotropic systems. The extended bounding box framework allows to attribute different properties to different grain boundary types of a polycrystalline microstructure and can be combined with explicit, implicit or semi-implicit time stepping strategies. To illustrate the applicability of the software, the simulation results of a case study are analysed. They indicate the impact of a misorientation dependent boundary energy formulation on the evolution of the misorientation distribution of the grain boundary types and on the individual growth rates of the grains as a function of the number of grain faces. (C) 2011 Elsevier B.V. All rights reserved.

  8. Bound on range precision for shot-noise limited ladar systems.

    Science.gov (United States)

    Johnson, Steven; Cain, Stephen

    2008-10-01

    The precision of ladar range measurements is limited by noise. The fundamental source of noise in a laser signal is the random time between photon arrivals. This phenomenon, called shot noise, is modeled as a Poisson random process. Other noise sources in the system are also modeled as Poisson processes. Under the Poisson-noise assumption, the Cramer-Rao lower bound (CRLB) on range measurements is derived. This bound on the variance of any unbiased range estimate is greater than the CRLB derived by assuming Gaussian noise of equal variance. Finally, it is shown that, for a ladar capable of dividing a fixed amount of energy into multiple laser pulses, the range precision is maximized when all energy is transmitted in a single pulse.

  9. Analysis of weak signal detection based on tri-stable system under Levy noise

    Science.gov (United States)

    Li-Fang, He; Ying-Ying, Cui; Tian-Qi, Zhang; Gang, Zhang; Ying, Song

    2016-06-01

    Stochastic resonance system is an effective method to extract weak signal. However, system output is directly influenced by system parameters. Aiming at this, the Levy noise is combined with a tri-stable stochastic resonance system. The average signal-to-noise ratio gain is regarded as an index to measure the stochastic resonance phenomenon. The characteristics of tri-stable stochastic resonance under Levy noise is analyzed in depth. First, the method of generating Levy noise, the effect of tri-stable system parameters on the potential function and corresponding potential force are presented in detail. Then, the effects of tri-stable system parameters w, a, b, and Levy noise intensity amplification factor D on the resonant output can be explored with different Levy noises. Finally, the tri-stable stochastic resonance system is applied to the bearing fault detection. Simulation results show that the stochastic resonance phenomenon can be induced by tuning the system parameters w, a, and b under different distributions of Levy noise, then the weak signal can be detected. The parameter intervals which can induce stochastic resonances are approximately equal. Moreover, by adjusting the intensity amplification factor D of Levy noise, the stochastic resonances can happen similarly. In bearing fault detection, the detection effect of the tri-stable stochastic resonance system is superior to the bistable stochastic resonance system. Project supported by the National Natural Science Foundation of China (Grant No. 61371164), the Chongqing Municipal Distinguished Youth Foundation, China (Grant No. CSTC2011jjjq40002), and the Research Project of Chongqing Municipal Educational Commission, China (Grant No. KJ130524).

  10. An Equivalent LMI Representation of Bounded Real Lemma for Continuous-Time Systems

    Directory of Open Access Journals (Sweden)

    Xie Wei

    2008-01-01

    Full Text Available Abstract An equivalent linear matrix inequality (LMI representation of bounded real lemma (BRL for linear continuous-time systems is introduced. As to LTI system including polytopic-type uncertainties, by using a parameter-dependent Lyapunov function, there are several LMIs-based formulations for the analysis and synthesis of performance. All of these representations only provide us with different sufficient conditions. Compared with previous methods, this new representation proposed here provides us the possibility to obtain better results. Finally, some numerical examples are illustrated to show the effectiveness of proposed method.

  11. Studies of light neutron-excess systems from bounds to continuum

    Directory of Open Access Journals (Sweden)

    Ito Makoto

    2011-10-01

    Full Text Available The generalized two-center cluster model (GTCM, which can handle various single particle config urations in general two center systems, is applied to the light neutron-rich system, 12Be= α+α+4N. We discuss the change of the neutrons’ configuratio around two α-cores as a variation of an excitation energy. We show that the covalent, ionic and atomic configuration appear in the unbound region above the α+8Heg.s. particledecay threshold. The GTCM calculation is also applied to even Be isotopes, and the systematics on the structural changes from bound region to continuum is discussed.

  12. Lower bounds for the ground-state degeneracies of frustrated systems on fractal lattices

    Science.gov (United States)

    Curado; Nobre

    2000-12-01

    The total number of ground states for nearest-neighbor-interaction Ising systems with frustrations, defined on hierarchical lattices, is investigated. A simple method is presented, which allows one to factorize the ground-state degeneracy, at a given hierarchy level n, in terms of contributions due to all hierarchy levels. Such a method may yield the exact ground-state degeneracy of uniformly frustrated systems, whereas it works as an approximation for randomly frustrated models. In the latter cases, it is demonstrated that such an approximation yields lower-bound estimates for the ground-state degeneracies.

  13. The Principle and Reflection on Determining the Mails Whole Delivery Standard of Time Bound in the Postal Central Office System

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper analyzes some problems arising in determining the mails Whole Delivery Standard of Time Bound (WDSTB) at present, and further on the basis of the postal central office system currently in practice, puts forward the principle, reflection and the concrete approaches in determining the Delivery Standard of Time Bound (DSTB).

  14. Detecting weak coupling in mesoscopic systems with a nonequilibrium Fano resonance

    Science.gov (United States)

    Xiao, S.; Yoon, Y.; Lee, Y.-H.; Bird, J. P.; Ochiai, Y.; Aoki, N.; Reno, J. L.; Fransson, J.

    2016-04-01

    A critical aspect of quantum mechanics is the nonlocal nature of the wave function, a characteristic that may yield unexpected coupling of nominally isolated systems. The capacity to detect this coupling can be vital in many situations, especially those in which its strength is weak. In this work, we address this problem in the context of mesoscopic physics, by implementing an electron-wave realization of a Fano interferometer using pairs of coupled quantum point contacts (QPCs). Within this scheme, the discrete level required for a Fano resonance is provided by pinching off one of the QPCs, thereby inducing the formation of a quasibound state at the center of its self-consistent potential barrier. Using this system, we demonstrate a form of nonequilibrium Fano resonance (NEFR), in which nonlinear electrical biasing of the interferometer gives rise to pronounced distortions of its Fano resonance. Our experimental results are captured well by a quantitative theoretical model, which considers a system in which a standard two-path Fano interferometer is coupled to an additional, intruder, continuum. According to this theory, the observed distortions in the Fano resonance arise only in the presence of coupling to the intruder, indicating that the NEFR provides a sensitive means to infer the presence of weak coupling between mesoscopic systems.

  15. Nonreciprocity light propagation in coupled microcavities system beyond weak-excitation approximation

    CERN Document Server

    Zheng, A S; Chen, H; Mei, T; Liu, J

    2016-01-01

    We propose an alternative scheme for nonreciprocal light propagation in two coupled cavities system, in which a two-level quantum emitter is coupled to one of the optical microcavities. For the case of parity-time (\\textrm{PT}) system (i.e., active-passive coupled cavities system), the cavity gain can significantly enhance the optical nonlinearity induced by the interaction between a quantum emitter and cavity field beyond weak-excitation approximation. The giant optical nonlinearity results in the non-lossy nonreciprocal light propagation with high isolation ratio in proper parameters range. In addition, our calculations show that nonreciprocal light propagation will not be affected by the unstable output field intensity caused by optical bistability and we can even switch directions of nonreciprocal light propagation by appropriately adjusting the system parameters.

  16. Lower bounds of concurrence for N-qubit systems and the detection of k-nonseparability of multipartite quantum systems

    Science.gov (United States)

    Qi, Xianfei; Gao, Ting; Yan, Fengli

    2017-01-01

    Concurrence, as one of the entanglement measures, is a useful tool to characterize quantum entanglement in various quantum systems. However, the computation of the concurrence involves difficult optimizations and only for the case of two qubits, an exact formula was found. We investigate the concurrence of four-qubit quantum states and derive analytical lower bound of concurrence using the multiqubit monogamy inequality. It is shown that this lower bound is able to improve the existing bounds. This approach can be generalized to arbitrary qubit systems. We present an exact formula of concurrence for some mixed quantum states. For even-qubit states, we derive an improved lower bound of concurrence using a monogamy equality for qubit systems. At the same time, we show that a multipartite state is k-nonseparable if the multipartite concurrence is larger than a constant related to the value of k, the qudit number and the dimension of the subsystems. Our results can be applied to detect the multipartite k-nonseparable states.

  17. 2-norm error bounds and estimates for Lanczos approximations to linear systems and rational matrix functions

    CERN Document Server

    Frommer, A; Lippert, Th; Rittich, H

    2012-01-01

    The Lanczos process constructs a sequence of orthonormal vectors v_m spanning a nested sequence of Krylov subspaces generated by a hermitian matrix A and some starting vector b. In this paper we show how to cheaply recover a secondary Lanczos process, starting at an arbitrary Lanczos vector v_m and how to use this secondary process to efficiently obtain computable error estimates and error bounds for the Lanczos approximations to a solution of a linear system Ax = b as well as, more generally, for the Lanczos approximations to the action of a rational matrix function on a vector. Our approach uses the relation between the Lanczos process and quadrature as developed by Golub and Meurant. It is different from methods known so far because of its use of the secondary Lanczos process. With our approach, it is now in particular possible to efficiently obtain upper bounds for the error in the 2-norm, provided a lower bound on the smallest eigenvalue of A is known. This holds for the error of the cg iterates as well ...

  18. Standard systems for measurement of pKs and ionic mobilities. 1. Univalent weak acids.

    Science.gov (United States)

    Slampová, Andrea; Krivánková, Ludmila; Gebauer, Petr; Bocek, Petr

    2008-12-05

    Determination of pK values of weak bases and acids by CZE has already attracted big attention in current practice and proved to offer the advantage of being applicable for mixtures of analytes. The method is based on the measurement of mobility curves plotting the effective mobility vs. the pH of the background electrolyte, and following computer-assisted regression involving corrections for ionic strength and temperature. To cover the necessary range of pH for a given case, both buffering weak acids and bases are used in one set of measurements, which requires implementing computations of individual ionic strength corrections for each pH value. It is also well known that some components of frequently used background electrolytes may interact with the analytes measured, on forming associates or complexes. This obviously deteriorates the reliability of the resulting data. This contribution brings a rational approach to this problem and establishes a standard system of anionic buffers for measurements of pKs and mobilities of weak acids, where the only counter cation present (besides H(+)) is Na(+). In this way, the risk of formation of complexes or associates of analytes with counter ions is strongly reduced. Moreover, the standard system of anionic buffers is selected in such a way that it provides, for an entire set of measurements, constant and accurately known ionic strength and the operational conditions are selected so that they provide constant Joule heating. Due to these precautions only one correction for ionic strength and temperature is needed for the obtained set of experimental data. This considerably facilitates their evaluation and regression analysis as the corrections need not be implemented in the computation software. The reliability and the advantages of the proposed system are well documented by experiments, where the known problematic group of phenol derivatives was measured with high accuracy and without any notice of anomalous behaviour.

  19. Dynamic Scheduling of Skippable Periodic Tasks With Energy Efficiency In Weakly Hard Real-Time System

    Directory of Open Access Journals (Sweden)

    Santhi Baskaran

    2010-12-01

    Full Text Available Energy consumption is a critical design issue in real-time systems, especially in battery- operated systems. Maintaining high performance, while extending the battery life between charges is an interesting challenge for system designers. Dynamic Voltage Scaling (DVS allows a processor to dynamically change speed and voltage at run time, thereby saving energy by spreading run cycles into idle time.Knowing when to use full power and when not, requires the cooperation of the operating system scheduler. Usually, higher processor voltage and frequency leads to higher system throughput whileenergy reduction can be obtained using lower voltage and frequency. Instead of lowering processorvoltage and frequency as much as possible, energy efficient real-time scheduling adjusts voltage andfrequency according to some optimization criteria, such as low energy consumption or high throughput,while it meets the timing constraints of the real-time tasks. As the quantity and functional complexity ofbattery powered portable devices continues to raise, energy efficient design of such devices has becomeincreasingly important. Many real-time scheduling algorithms have been developed recently to reduceenergy consumption in the portable devices that use DVS capable processors. Extensive power awarescheduling techniques have been published for energy reduction, but most of them have been focusedsolely on reducing the processor energy consumption. While the processor is one of the major powerhungry units in the system, other peripherals such as network interface card, memory banks, disks alsoconsume significant amount of power. Dynamic Power Down (DPD technique is used to reduce energyconsumption by shutting down the processing unit and peripheral devices, when the system is idle. Threealgorithms namely Red Tasks Only (RTO, Blue When Possible (BWP and Red as Late as Possible (RLPare proposed in the literature to schedule the real-time tasks in Weakly-hard real

  20. On uniqueness and existence of entropy solutions of weakly coupled systems of nonlinear degenerate parabolic equations

    Directory of Open Access Journals (Sweden)

    Helge Holden

    2003-04-01

    Full Text Available We prove existence and uniqueness of entropy solutions for the Cauchy problem of weakly coupled systems of nonlinear degenerate parabolic equations. We prove existence of an entropy solution by demonstrating that the Engquist-Osher finite difference scheme is convergent and that any limit function satisfies the entropy condition. The convergence proof is based on deriving a series of a priori estimates and using a general $L^p$ compactness criterion. The uniqueness proof is an adaption of Kruzkov's ``doubling of variables'' proof. We also present a numerical example motivated by biodegradation in porous media.

  1. Nonlinear stochastic optimal bounded control of hysteretic systems with actuator saturation

    Institute of Scientific and Technical Information of China (English)

    Rong-hua HUAN; Wei-qiu ZHU; Yong-jun WU

    2008-01-01

    A modified nonlinear stochastic optimal bounded control strategy for random excited hysteretic systems with actuator saturation is proposed. First, a controlled hysteretic system is converted into an equivalent nonlinear nonhysteretic stochastic system. Then, the partially averaged It6 stochastic differential equation and dynamical programming equation are established, respectively, by using the stochastic averaging method for quasi non-integrable Hamiltonian systems and stochastic dynamical programming principle, from which the optimal control law consisting of optimal unbounded control and bang-bang control is derived. Finally, the response of optimally controlled system is predicted by solving the Fokker-Planck-Kolmogorov (FPK) equation associated with the fully averaged It6 equation. Numerical results show that the proposed control strategy has high control effectiveness and efficiency.

  2. Nonlinear control for global stabilization of multiple-integrator system by bounded controls

    Institute of Scientific and Technical Information of China (English)

    Bin ZHOU; Guangren DUAN; Liu ZHANG

    2008-01-01

    The global stabilization problem of the multiple-integrator system by bounded controls is considered.A nonlinear feedback law consisting of nested saturation functions is proposed.This type of nonlinear feedback law that is a modification and generalization of the result given in[1] needs only[(n+1)/2](n is the dimensions of the system)saturation elements,which is fewer than that which the other nonlinear laws need.Funhermore.the poles of the closedloop system Can be placed on any location on the left real axis when none of the saturafion elements in the control laws is saturated.This type of nonlinear control law exhibits a simpler structure and call significantly improve the transient performances of the closed-loop system,and is very superior to the other existing methods.Simulation on a fourth-order system is used to validate the proposed method.

  3. Adaptive fuzzy predictive sliding control of uncertain nonlinear systems with bound-known input delay.

    Science.gov (United States)

    Khazaee, Mostafa; Markazi, Amir H D; Omidi, Ehsan

    2015-11-01

    In this paper, a new Adaptive Fuzzy Predictive Sliding Mode Control (AFP-SMC) is presented for nonlinear systems with uncertain dynamics and unknown input delay. The control unit consists of a fuzzy inference system to approximate the ideal linearization control, together with a switching strategy to compensate for the estimation errors. Also, an adaptive fuzzy predictor is used to estimate the future values of the system states to compensate for the time delay. The adaptation laws are used to tune the controller and predictor parameters, which guarantee the stability based on a Lyapunov-Krasovskii functional. To evaluate the method effectiveness, the simulation and experiment on an overhead crane system are presented. According to the obtained results, AFP-SMC can effectively control the uncertain nonlinear systems, subject to input delays of known bound.

  4. Global stabilization of linear systems by bounded controls with guaranteed poles

    Institute of Scientific and Technical Information of China (English)

    ZHOU Bin; DUAN GuangRen

    2008-01-01

    The global stabilization of asymptotically null controllable linear systems by bounded control is considered. A nested type saturation control law is proposed which is a generalization of the existing results reported in the literature. The primary characteristic of this modified control law is that more design parameters, which are the closed-loop eigenvalues when the system is operating in linear form, are intro-duced and which can be well designed to achieve better system performance. Using this law, the pole locations of the closed-loop systems depending on a linear trans-formation can be placed arbitrarily within certain areas. Numerical example shows that the performance of the closed-loop system under this control law can be signif-icantly improved if the free parameters are properly chosen.

  5. Lanthanide(III) complexes of aminoethyl-DO3A as PARACEST contrast agents based on decoordination of the weakly bound amino group.

    Science.gov (United States)

    Krchová, Tereza; Kotek, Jan; Jirák, Daniel; Havlíčková, Jana; Císařová, Ivana; Hermann, Petr

    2013-11-28

    2-Aminoethyl DOTA analogues with unsubstituted (H3L1), monomethylated (H3L2) and dimethylated (H3L3) amino groups were prepared by improved synthetic procedures. Their solid-state structures exhibit an extensive system of intramolecular hydrogen bonds, which is probably present in solution and leads to the rather high value of the last dissociation constant. The protonation sequence of H3L1 in solution corresponds to that found in the solid state. The stability constants of the H3L1 complexes with La(3+) and Gd(3+) (20.02 and 22.23, respectively) are similar to those of DO3A and the reduction of the pK(A) value of the pendant amino group from 10.51 in the free ligand to 6.06 and 5.83 in the La(3+) and Gd(3+) complexes, respectively, points to coordination of the amino group. It was confirmed in the solid state structure of the [Yb(L1)] complex, where disorder between the SA' and TSA' isomers was found. A similar situation is expected in solution, where a fast equilibration among the isomers hampers the unambiguous determination of the isomer ratio in solution. The PARACEST effect was observed in Eu(III)-H3L1/H3L2 and Yb(III)-H3L1/H3L2 complexes, being dependent on pH in the region of 4.5-7.5 and pH-independent in more alkaline solutions. The decrease of the PARACEST effect parallels with the increasing abundance of the complex protonated species, where the pendant amino group is not coordinating. Surprisingly, a small PARACEST effect was also observed in solutions of Eu(III)/Yb(III)-H3L3 complexes, where the pendant amino group is dimethylated. The effect is detectable in a narrow pH region, where both protonated and deprotonated complex species are present in equilibrium. The data points to the new mechanism of the PARACEST effect, where the slow coordination-decoordination of the pendant amine is coupled with the fast proton exchange between the free amino group and bulk water mediates the magnetization transfer. The pH-dependence of the effect was proved to be

  6. Existence and stability of weak solutions for a degenerate parabolic system modelling two-phase flows in porous media

    CERN Document Server

    Escher, Joachim; Matioc, Bogdan-Vasile

    2011-01-01

    We prove global existence of nonnegative weak solutions to a degenerate parabolic system which models the interaction of two thin fluid films in a porous medium. Furthermore, we show that these weak solutions converge at an exponential rate towards flat equilibria.

  7. Collective dynamics of multimode bosonic systems induced by weak quantum measurement

    Science.gov (United States)

    Mazzucchi, Gabriel; Kozlowski, Wojciech; Caballero-Benitez, Santiago F.; Mekhov, Igor B.

    2016-07-01

    In contrast to the fully projective limit of strong quantum measurement, where the evolution is locked to a small subspace (quantum Zeno dynamics), or even frozen completely (quantum Zeno effect), the weak non-projective measurement can effectively compete with standard unitary dynamics leading to nontrivial effects. Here we consider global weak measurement addressing collective variables, thus preserving quantum superpositions due to the lack of which path information. While for certainty we focus on ultracold atoms, the idea can be generalized to other multimode quantum systems, including various quantum emitters, optomechanical arrays, and purely photonic systems with multiple-path interferometers (photonic circuits). We show that light scattering from ultracold bosons in optical lattices can be used for defining macroscopically occupied spatial modes that exhibit long-range coherent dynamics. Even if the measurement strength remains constant, the quantum measurement backaction acts on the atomic ensemble quasi-periodically and induces collective oscillatory dynamics of all the atoms. We introduce an effective model for the evolution of the spatial modes and present an analytic solution showing that the quantum jumps drive the system away from its stable point. We confirm our finding describing the atomic observables in terms of stochastic differential equations.

  8. Italian industrial districts: A model of success or a weak productive system?

    Directory of Open Access Journals (Sweden)

    Daniele Schilirò

    2012-10-01

    Full Text Available The present contribution focuses on two issues. The first one concerns the characteristics of industrial districts and the increasing weight of these districts in the Italian system of production. The second issue is about the competitiveness of the Italian industrial districts, if they represent a model of success or rather a weak system of production. Thus, the transformation of the industrial districts is examined and the strengths and weaknesses are highlighted. One argument that comes out of this investigation is that industrial districts are strongly influenced by institutions, territory, and also by the social and cultural environment. The second argument regards the competitiveness of this Italian industrial development model, based on SMEs, which is founded on the specialization of productions, on innovation and internationalization. The paper argues that this model, which represents the ``Made in Italy'', is still a strong and dynamic system which has shown good performances and it represents a paradigm of lasting competitiveness, even if it is restrained by many external chronic constraints.

  9. EFFICIENT BIT ERROR PROBABILITY EXPRESSION AND VERY TIGHT BOUND FOR MAXIMAL RATIO COMBINING DIVERSITY SYSTEMS OVER RAYLEIGH FADING CHANNEL

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Bit Error Probability (BEP) provides a fundamental performance measure for wireless diversity systems. This paper presents two new exact BEP expressions for Maximal Ratio Combining (MRC) diversity systems. One BEP expression takes a closed form, while the other is derived by treating the squared-sum of Rayleigh random variables as an Erlang variable. Due to the fact that the extant bounds are loose and could not properly characterize the error performance of MRC diversity systems, this paper presents a very tight bound. The numerical analysis shows that the new derived BEP expressions coincide with the extant expressions, and that the new approximation tightly bounds the accurate BEP.

  10. Capture zone of a multi-well system in bounded peninsula-shaped aquifers.

    Science.gov (United States)

    Zarei-Doudeji, Somayeh; Samani, Nozar

    2014-08-01

    In this paper we present the equation of capture zone for multi-well system in peninsula-shaped confined and unconfined aquifers. The aquifer is rectangular in plan view, bounded along three sides, and extends to infinity at the fourth side. The bounding boundaries are either no-flow (impervious) or in-flow (constant head) so that aquifers with six possible boundary configurations are formed. The well system is consisted of any number of extraction or injection wells or combination of both with any flow rates. The complex velocity potential equations for such a well-aquifer system are derived to delineate the capture envelop. Solutions are provided for the aquifers with and without a uniform regional flow of any directions. The presented equations are of general character and have no limitations in terms of well numbers, positions and types, extraction/injection rate, and regional flow rate and direction. These solutions are presented in form of capture type curves which are useful tools in hands of practitioners to design in-situ groundwater remediation systems, to contain contaminant plumes, to evaluate the surface-subsurface water interaction and to verify numerical models.

  11. A Study of the Weak Shock Wave Propagating over a Porous Wall/Cavity System

    Institute of Scientific and Technical Information of China (English)

    H.D.KIM; S.J.JUNG; T.AOKI; T.SETOGUCHI

    2005-01-01

    The present computational study addresses the attenuation of the shock wave propagating in a duct, using a porous wall/cavity system. In the present study, a weak shock wave propagating over the porous wall/cavity system is investigated with computational fluid dynamics. A total variation diminishing scheme is employed to solve the unsteady, two-dimensional, compressible, Navier-Stokes equations. The Mach number of an initial shock wave is changed in the range from 1.02 to 1.12. Several different types of porous wall/cavity systems are tested to investigate the passive control effects. The results show that wall pressure strongly fluctuates due to diffraction and reflection processes of the shock waves behind the incident shock wave. From the results, it is understood that for effective alleviation of tunnel impulse waves, the length of the perforated region should be sufficiently long.

  12. The frequency characteristic of chaotic synchronization systems and weak signal detection

    Institute of Scientific and Technical Information of China (English)

    裴留庆; 匡锦瑜; 邵媛

    1997-01-01

    A concept of frequency character of a chaotic synchronized system (CHSS) is proposed. The nature of the system can be described in the frequency domain with the concept. A simple model to measure the frequency character is designed, and the characteristic curve of Chua’s CHSS is obtained. Some results from theoretical analysis and numerical simulation indicate that the system possesses multiband of frequencies with distinct features shown in each band. Thus it may offer various resources of frequencies, fn particular, it is capable of detecting weak signals drowned in noise in some bands. Both the concept of frequency character and the characteristic curve of CHSS provide a scientific basis for us to gain a deeper insight into the inherent function of information processing in CHSS, and to utilize properly the information resources of CHSS as well.

  13. [Analysing strengths and weaknesses: opportunities and threats for service providers in the German health care system].

    Science.gov (United States)

    Hensen, Peter; Wollert, Silke; Schawrz, Thomas; Luger, Thomas; Roeder, Norbert

    2003-05-01

    Hospitals in the German health care system are confronted with increasing economic competition due to paradigm shifts in funding inpatient treatment. Major hospitals, such as university hospitals, will be under significantly greater pressure to keep up the ability to compete by uniform per case payment. The new hospital funding system based on a Diagnosis Related Group (DRG) system and the economic competition involved require analyses of organisational and locational factors. Cooperativeness and efficient utilisation of resources, properties and staff will be determining factors to secure existence. Adequate responses and strategies are essential to cope with the growing operating requirements. Carrying out an analysis identifying one's own strengths and weaknesses, opportunities and threats will help to focus activities and sustainable strategies into areas where the strengths and the greatest opportunities lie. An example of the process of strategic planning and positioning is shown for a university department of dermatology.

  14. Stochastic optimal bounded control of MDOF quasi nonintegrable-hamiltonian systems with actuator saturation

    Energy Technology Data Exchange (ETDEWEB)

    Huan, Ronghua; Zhu, Weiqiu [Zhejiang University, Department of Mechanics, State Key Laboratory of Fluid Power Transmission and Control, Hangzhou (China); Wu, Yongjun [East China University of Science and Technology, School of Information Science and Engineering, Shanghai (China)

    2009-02-15

    A new bounded optimal control strategy for multi-degree-of-freedom (MDOF) quasi nonintegrable-Hamiltonian systems with actuator saturation is proposed. First, an n-degree-of-freedom (n-DOF) controlled quasi nonintegrable-Hamiltonian system is reduced to a partially averaged Ito stochastic differential equation by using the stochastic averaging method for quasi nonintegrable-Hamiltonian systems. Then, a dynamical programming equation is established by using the stochastic dynamical programming principle, from which the optimal control law consisting of optimal unbounded control and bang-bang control is derived. Finally, the response of the optimally controlled system is predicted by solving the Fokker-Planck-Kolmogorov (FPK) equation associated with the fully averaged Ito equation. An example of two controlled nonlinearly coupled Duffing oscillators is worked out in detail. Numerical results show that the proposed control strategy has high control effectiveness and efficiency and that chattering is reduced significantly compared with the bang-bang control strategy. (orig.)

  15. Numerical approach to the lowest bound state of muonic three-body systems

    CERN Document Server

    Khan, Md Abdul

    2015-01-01

    In this paper, calculated energies of the lowest bound state of Coulomb three-body systems containing an electron ($e^-$), a negatively charged muon ($\\mu^-$) and a nucleus ($N^{Z+}$) of charge number Z are reported. The 3-body relative wave function in the resulting Schr\\"odinger equation is expanded in the complete set of hyperspherical harmonics (HH). Use of the orthonormality of HH leads to an infinite set of coupled differential equations (CDE) which are solved numerically to get the energy E.

  16. AN AFFINE SCALING INTERIOR ALGORITHM VIA CONJUGATE GRADIENT PATH FOR SOLVING BOUND-CONSTRAINED NONLINEAR SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    Chunxia Jia; Detong Zhu

    2008-01-01

    In this paper we propose an affine scaling interior algorithm via conjugate gradient path for solving nonlinear equality systems subject to bounds on variables.By employing the affine scaling conjugate gradient path search strategy,we obtain an iterative direction by solving the linearize model.By using the line search technique,we will find an acceptable trial step length along this direction which is strictly feasible and makes the objective function nonmonotonically decreasing.The global convergence and fast local convergence rate of the proposed algorithm are established under some reasonable conditions.Furthermore,the numerical results of the proposed algorithm indicate to be effective.

  17. Cryptanalysis of Pasargad, A Distance Bounding Protocol Based on RFID System

    Directory of Open Access Journals (Sweden)

    Mahdi Azizi

    2012-08-01

    Full Text Available In this paper we analyze an authentication protocol so-called Pasargad which proposed by Arjemand et al. [1]. The Pasargad protocol is a distance bounding protocol which has been designed for RFID-based electronic voting systems. The designers have claimed that this protocol is more secure than Preneel and Single protocol [2], against relay attacks. However, in this paper, we present some efficient attacks against it. Our attacks include conditional impersonation attack and recovery key attack. Moreover, we show that this protocol has some structural flaw which may prevent to execution the protocol.

  18. A Novel Blind Source Separation Algorithm and Performance Analysis of Weak Signal against Strong Interference in Passive Radar Systems

    Directory of Open Access Journals (Sweden)

    Chengjie Li

    2016-01-01

    Full Text Available In Passive Radar System, obtaining the mixed weak object signal against the super power signal (jamming is still a challenging task. In this paper, a novel framework based on Passive Radar System is designed for weak object signal separation. Firstly, we propose an Interference Cancellation algorithm (IC-algorithm to extract the mixed weak object signals from the strong jamming. Then, an improved FastICA algorithm with K-means cluster is designed to separate each weak signal from the mixed weak object signals. At last, we discuss the performance of the proposed method and verify the novel method based on several simulations. The experimental results demonstrate the effectiveness of the proposed method.

  19. Fundamental delay bounds in peer-to-peer chunk-based real-time streaming systems

    CERN Document Server

    Bianchi, Giuseppe; Bracciale, Lorenzo; Piccolo, Francesca Lo; Salsano, Stefano

    2009-01-01

    This paper addresses the following foundational question: what is the maximum theoretical delay performance achievable by an overlay peer-to-peer streaming system where the streamed content is subdivided into chunks? As shown in this paper, when posed for chunk-based systems, and as a consequence of the store-and-forward way in which chunks are delivered across the network, this question has a fundamentally different answer with respect to the case of systems where the streamed content is distributed through one or more flows (sub-streams). To circumvent the complexity emerging when directly dealing with delay, we express performance in term of a convenient metric, called "stream diffusion metric". We show that it is directly related to the end-to-end minimum delay achievable in a P2P streaming network. In an homogeneous scenario, we derive a performance bound for such metric, and we show how this bound relates to two fundamental parameters: the upload bandwidth available at each node, and the number of neigh...

  20. Probability of loss of assured safety in temperature dependent systems with multiple weak and strong links.

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Jay Dean (ProStat, Mesa, AZ); Oberkampf, William Louis; Helton, Jon Craig (Arizona State University, Tempe, AZ)

    2004-12-01

    Relationships to determine the probability that a weak link (WL)/strong link (SL) safety system will fail to function as intended in a fire environment are investigated. In the systems under study, failure of the WL system before failure of the SL system is intended to render the overall system inoperational and thus prevent the possible occurrence of accidents with potentially serious consequences. Formal developments of the probability that the WL system fails to deactivate the overall system before failure of the SL system (i.e., the probability of loss of assured safety, PLOAS) are presented for several WWSL configurations: (i) one WL, one SL, (ii) multiple WLs, multiple SLs with failure of any SL before any WL constituting failure of the safety system, (iii) multiple WLs, multiple SLs with failure of all SLs before any WL constituting failure of the safety system, and (iv) multiple WLs, multiple SLs and multiple sublinks in each SL with failure of any sublink constituting failure of the associated SL and failure of all SLs before failure of any WL constituting failure of the safety system. The indicated probabilities derive from time-dependent temperatures in the WL/SL system and variability (i.e., aleatory uncertainty) in the temperatures at which the individual components of this system fail and are formally defined as multidimensional integrals. Numerical procedures based on quadrature (i.e., trapezoidal rule, Simpson's rule) and also on Monte Carlo techniques (i.e., simple random sampling, importance sampling) are described and illustrated for the evaluation of these integrals. Example uncertainty and sensitivity analyses for PLOAS involving the representation of uncertainty (i.e., epistemic uncertainty) with probability theory and also with evidence theory are presented.

  1. EXISTENCE AND UNIQUENESS OF STRONG PERIODIC SOLUTION OF THE EVOLUTION SYSTEM DESCRIBING GEOPHYSICAL FLOW PART I: IN BOUNDED DOMAINS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The existence and uniqueness of a strong periodic solution of the evolution system describing geophysical flow in bounded domains of RN(N = 3, 4) are proven if external forces are periodic in time and sufficiently small.

  2. Identifying weak points of urban drainage systems by means of VulNetUD.

    Science.gov (United States)

    Möderl, M; Kleidorfer, M; Sitzenfrei, R; Rauch, W

    2009-01-01

    This article presents the development and application of the software tool VulNetUD. VulNetUD is a tool for GIS-based identification of vulnerable sites of urban drainage systems (UDS) using hydrodynamic simulations undertaken using EPA SWMM. The benefit of the tool is the output of different vulnerability maps rating sewer surcharging, sewer flooding, combined sewer overflow (CSO) efficiency and CSO emissions. For this, seven predefined performance indicators are used to evaluate urban drainage systems under abnormal, critical and future conditions. The application on a case study highlights the capability of the tool to identify weak points of the urban drainage systems. Thereby it is possible to identify urban drainage system components which cause the highest performance decrease across the entire system. The application of the method on a real world case study shows for instance that a reduction of catchment areas which are located upstream of CSOs with relatively less capacity in the downstream sewers achieves the highest increases efficiency of the system. Finally, the application of VulNetUD is seen as a valuable tool for managers and operators of waste water utilities to improve the efficiency of their systems. Additionally vulnerability maps generated by VulNetUD support risk management e.g. decision making in urban development planning or the development of rehabilitation strategies.

  3. Correlation of the Rock Mass Rating (RMR) System with the Unified Soil Classification System (USCS): Introduction of the Weak Rock Mass Rating System (W-RMR)

    Science.gov (United States)

    Warren, Sean N.; Kallu, Raj R.; Barnard, Chase K.

    2016-11-01

    Underground gold mines in Nevada are exploiting increasingly deeper ore bodies comprised of weak to very weak rock masses. The Rock Mass Rating (RMR) classification system is widely used at underground gold mines in Nevada and is applicable in fair to good-quality rock masses, but is difficult to apply and loses reliability in very weak rock mass to soil-like material. Because very weak rock masses are transition materials that border engineering rock mass and soil classification systems, soil classification may sometimes be easier and more appropriate to provide insight into material behavior and properties. The Unified Soil Classification System (USCS) is the most likely choice for the classification of very weak rock mass to soil-like material because of its accepted use in tunnel engineering projects and its ability to predict soil-like material behavior underground. A correlation between the RMR and USCS systems was developed by comparing underground geotechnical RMR mapping to laboratory testing of bulk samples from the same locations, thereby assigning a numeric RMR value to the USCS classification that can be used in spreadsheet calculations and geostatistical analyses. The geotechnical classification system presented in this paper including a USCS-RMR correlation, RMR rating equations, and the Geo-Pick Strike Index is collectively introduced as the Weak Rock Mass Rating System (W-RMR). It is the authors' hope that this system will aid in the classification of weak rock masses and more usable design tools based on the RMR system. More broadly, the RMR-USCS correlation and the W-RMR system help define the transition between engineering soil and rock mass classification systems and may provide insight for geotechnical design in very weak rock masses.

  4. Outline the strengths and weaknesses of performance-related pay (PRP) systems and assess their overall value

    Institute of Scientific and Technical Information of China (English)

    廖雯静

    2015-01-01

    Performance-related pay is very important in the aspect of human resource in an organization. However, it also has some weaknesses. This article analyzes the performance-related pay (PRP) system from an overall point of view.

  5. Weak Links The Universal Key to the Stability of Networks and Complex Systems

    CERN Document Server

    Csermely, Peter

    2009-01-01

    How can our societies be stabilized in a crisis? Why can we enjoy and understand Shakespeare? Why are fruitflies uniform? How do omnivorous eating habits aid our survival? What makes the Mona Lisa’s smile beautiful? How do women keep our social structures intact? – Could there possibly be a single answer to all these questions? This book shows that the statement: "weak links stabilize complex systems" provides the key to understanding each of these intriguing puzzles, and many others too. The author (recipient of several distinguished science communication prizes) uses weak (low affinity, low probability) interactions as a thread to introduce a vast variety of networks from proteins to economics and ecosystems. Many people, from Nobel Laureates to high-school students have helped to make the book understandable to all interested readers. This unique book and the ideas it develops will have a significant impact on many, seemingly diverse, fields of study. A very personal, engaging, and unique book that wil...

  6. Partitioning in aqueous two-phase systems: Analysis of strengths, weaknesses, opportunities and threats.

    Science.gov (United States)

    Soares, Ruben R G; Azevedo, Ana M; Van Alstine, James M; Aires-Barros, M Raquel

    2015-08-01

    For half a century aqueous two-phase systems (ATPSs) have been applied for the extraction and purification of biomolecules. In spite of their simplicity, selectivity, and relatively low cost they have not been significantly employed for industrial scale bioprocessing. Recently their ability to be readily scaled and interface easily in single-use, flexible biomanufacturing has led to industrial re-evaluation of ATPSs. The purpose of this review is to perform a SWOT analysis that includes a discussion of: (i) strengths of ATPS partitioning as an effective and simple platform for biomolecule purification; (ii) weaknesses of ATPS partitioning in regard to intrinsic problems and possible solutions; (iii) opportunities related to biotechnological challenges that ATPS partitioning may solve; and (iv) threats related to alternative techniques that may compete with ATPS in performance, economic benefits, scale up and reliability. This approach provides insight into the current status of ATPS as a bioprocessing technique and it can be concluded that most of the perceived weakness towards industrial implementation have now been largely overcome, thus paving the way for opportunities in fermentation feed clarification, integration in multi-stage operations and in single-step purification processes.

  7. Chemoconvection patterns in the methylene-blue-glucose system: Weakly nonlinear analysis

    Science.gov (United States)

    Pons, A. J.; Sagués, F.; Bees, M. A.

    2004-12-01

    The oxidation of solutions of glucose with methylene-blue as a catalyst in basic media can induce hydrodynamic overturning instabilities, termed chemoconvection in recognition of their similarity to convective instabilities. The phenomenon is due to gluconic acid, the marginally dense product of the reaction, which gradually builds an unstable density profile. Experiments indicate that dominant pattern wavenumbers initially increase before gradually decreasing or can even oscillate for long times. Here, we perform a weakly nonlinear analysis for an established model of the system with simple kinetics, and show that the resulting amplitude equation is analogous to that obtained in convection with insulating walls. We show that the amplitude description predicts that dominant pattern wavenumbers should decrease in the long term, but does not reproduce the aforementioned increasing wavenumber behavior in the initial stages of pattern development. We hypothesize that this is due to horizontally homogeneous steady states not being attained before pattern onset. We show that the behavior can be explained using a combination of pseudo-steady-state linear and steady-state weakly nonlinear theories. The results obtained are in qualitative agreement with the analysis of experiments.

  8. Hypogonadism in patients with chronic obstructive pulmonary disease: relationship with airflow limitation, muscle weakness and systemic inflammation

    Directory of Open Access Journals (Sweden)

    Rasha Galal Daabis

    2016-03-01

    Conclusion: Hypogonadism is highly prevalent in clinically stable COPD patients and is particularly related to the severity of the airway obstruction. Systemic inflammation is present in stable COPD patients and its intensity is related to the severity of the underlying disease and it predisposes to skeletal muscle weakness and exercise intolerance. However, we failed to find a significant association between hypogonadism and muscle weakness or systemic inflammation.

  9. General Explicit Solution of Planar Weakly Delayed Linear Discrete Systems and Pasting Its Solutions

    Directory of Open Access Journals (Sweden)

    Josef Diblík

    2014-01-01

    Full Text Available Planar linear discrete systems with constant coefficients and delays x(k+1=Ax(k+∑l=1n‍Blxl(k-ml are considered where k∈ℤ0∞:={0,1,…,∞}, m1,m2,…,mn are constant integer delays, 0system is weakly delayed. The characteristic equations of such systems are identical with those for the same systems but without delayed terms. In this case, after several steps, the space of solutions with a given starting dimension 2(mn+1 is pasted into a space with a dimension less than the starting one. In a sense, this situation is analogous to one known in the theory of linear differential systems with constant coefficients and special delays when the initially infinite dimensional space of solutions on the initial interval turns (after several steps into a finite dimensional set of solutions. For every possible case, explicit general solutions are constructed and, finally, results on the dimensionality of the space of solutions are obtained.

  10. Performance Comparison of Voltage Stability Indices for Weak Bus Identification in Power Systems

    Science.gov (United States)

    Verayiah, R.; Mohamed, A.; Shareef, H.; Zainal Abidin, I. Hj

    2013-06-01

    Voltage collapse event is identified as complex and localized in nature but its effect is extensive once occurred. The vital effect of voltage collapse would be the total system collapse or blackouts which would cost a large loss to utility companies. Eventually, on- line monitoring of power system stability has become an important factor for electric power utilities. The last utmost option to avert voltage collapse incident from occurring is by the implementation of under voltage load shedding scheme. The identification of location for load shedding is the main motivation of the study. The weakest bus in a power system is identified as the location for load shedding. This location is obtained using voltage stability index Ld. The performance and effectiveness of Ld index is compared with Fast Voltage Stability Index (FVSI) and Le Index. The results obtained indicate that Ld Index can be used to identify the weak bus in a power system and consequently for the placement of UVLS relays in a power system network.

  11. Distributed output regulation for multi-agent systems with norm-bounded uncertainties

    Science.gov (United States)

    Yu, Lu; Wang, Jinzhi

    2014-11-01

    In this paper, we consider the distributed robust output regulation problem for multi-agent systems (MASs). It is involved with a group of heterogeneous high-order linear uncertain systems and an linear exosystem. The regulated output is a combination of the output of MAS and the exosystem, which is defined based on controlling demands. Distributed controllers are designed to ensure that the regulated output converges to the origin and meanwhile the closed-loop MAS is stable. The sufficient conditions for the solvability of distributed output regulation problem are given in terms of linear matrix inequalities. And algorithms are proposed to design distributed dynamic controllers with state feedback and output feedback, via the help of internal models. It is shown that, for any time-invariant norm-bounded uncertainties, the given controllers can realise the objective of output regulation.

  12. A Branch and Bound Method to the Continuous Time Model Elevator System with Full Information

    Science.gov (United States)

    Shen, Zhen; Zhao, Qianchuan

    A new Branch and Bound method is given for the scheduling of the group elevator system with full information. Full information means that not only the parameters of the elevator systems but also the arrival time, origins and destinations of all the passengers who are to be served are known beforehand. The performance obtained by solving the full information problem is the best performance that the elevator scheduling algorithm can achieve and then can be used to measure how good an elevator scheduling algorithm is. The method can handle the continuous time event and is based on the concept of “trip”, which refers to the movement of the car without changing the direction and with at least one passenger being served.

  13. Common phase error estimation in coherent optical OFDM systems using best-fit bounding box.

    Science.gov (United States)

    Bo, Tianwai; Chan, Chun-Kit

    2016-10-17

    In this paper, we investigate and characterize a new approach of adopting best-fit bounding box method for common phase error estimation in coherent optical OFDM systems. The method is based on the calculation of the 2-D convex hull of the received signal constellation, which is generally adopted in image processing area to correct the skew of images. We further perform detailed characterizations including root mean square error analysis, laser linewidth tolerance, noise tolerance, and computation complexity analysis, via numerical simulations and experiments. The results show the proposed method achieves much improved spectral efficiency and comparable system performance than the pilot-aided method, while it exhibits good estimation accuracy and reduced complexity than the blind phase searching method.

  14. Weak relativity

    CERN Document Server

    Selleri, Franco

    2015-01-01

    Weak Relativity is an equivalent theory to Special Relativity according to Reichenbach’s definition, where the parameter epsilon equals to 0. It formulates a Neo-Lorentzian approach by replacing the Lorentz transformations with a new set named “Inertial Transformations”, thus explaining the Sagnac effect, the twin paradox and the trip from the future to the past in an easy and elegant way. The cosmic microwave background is suggested as a possible privileged reference system. Most importantly, being a theory based on experimental proofs, rather than mutual consensus, it offers a physical description of reality independent of the human observation.

  15. Strong and Weak Convergence Criteria of Composite Iterative Algorithms for Systems of Generalized Equilibria

    Directory of Open Access Journals (Sweden)

    Lu-Chuan Ceng

    2014-01-01

    Full Text Available We first introduce and analyze one iterative algorithm by using the composite shrinking projection method for finding a solution of the system of generalized equilibria with constraints of several problems: a generalized mixed equilibrium problem, finitely many variational inequalities, and the common fixed point problem of an asymptotically strict pseudocontractive mapping in the intermediate sense and infinitely many nonexpansive mappings in a real Hilbert space. We prove a strong convergence theorem for the iterative algorithm under suitable conditions. On the other hand, we also propose another iterative algorithm involving no shrinking projection method and derive its weak convergence under mild assumptions. Our results improve and extend the corresponding results in the earlier and recent literature.

  16. Decay of the resonance fluorescence following pulsed excitation of a weakly disordered excitonic system

    Science.gov (United States)

    Boukahil, A.; Huber, D. L.

    1993-12-01

    A study is made of the decay of the resonance fluorescence following pulsed excitation of a weakly disordered system whose optical excitations are Frenkel excitons. The disorder is characterized by a Gaussian distribution of optical transition frequencies with no correlation between different sites. The duration of the resonant pulse is taken to be short in comparison with the reciprocal of the optical linewidth, and the wavelength of the light is assumed to be large in comparison with either the size of the array or the exciton mean free path associated with the disorder. In the limit where σ, the standard deviation of the Gaussian distribution, is much less than the exciton bandwidth, the integrated intensity of the fluorescence decays non-exponentially and is characterized by universal functions of σ xt, where x= 4/3, 2, and 4 in one, two, and three dimensions, respectively. Analytic approximations to the scaling functions in two and three dimensions are presented.

  17. Weak constraint four-dimensional variational data assimilation in a model of the California Current System

    Science.gov (United States)

    Crawford, William J.; Smith, Polly J.; Milliff, Ralph F.; Fiechter, Jerome; Wikle, Christopher K.; Edwards, Christopher A.; Moore, Andrew M.

    2016-12-01

    A new approach is explored for computing estimates of the error covariance associated with the intrinsic errors of a numerical forecast model in regions characterized by upwelling and downwelling. The approach used is based on a combination of strong constraint data assimilation, twin model experiments, linear inverse modeling, and Bayesian hierarchical modeling. The resulting model error covariance estimates Q are applied to a model of the California Current System using weak constraint four-dimensional variational (4D-Var) data assimilation to compute estimates of the ocean circulation. The results of this study show that the estimates of Q derived following our approach lead to demonstrable improvements in the model circulation estimates and isolate regions where model errors are likely to be important and that have been independently identified in the same model in previously published work.

  18. Inverse systems, Gelfand-Tsetlin patterns and the weak Lefschetz property

    CERN Document Server

    Harbourne, Brian; Seceleanu, Alexandra

    2010-01-01

    Migliore--Mir\\'o-Roig--Nagel [Trans. A.M.S. to appear, arXiv: 0811.1023] show that the weak Lefschetz property (WLP) can fail for an ideal I in K[x_1,x_2,x_3,x_4] generated by powers of linear forms. This is in contrast to the analogous situation in K[x_1,x_2,x_3], where WLP always holds [Proc. A.M.S. 2010, arXiv:0911.0876]. We use the inverse system dictionary to connect I to an ideal of fat points, and show that failure of WLP for powers of linear forms is connected to the geometry of the associated fat point scheme. Recent results of Sturmfels-Xu in [J. Eur. Math. Soc. 2010, arXiv:0803.0892] allow us to relate WLP to Gelfand-Tsetlin patterns. See Friday's posting by Migliore--Mir\\'o-Roig--Nagel for related results.

  19. Competitive or weak cooperative stochastic Lotka-Volterra systems conditioned on non-extinction.

    Science.gov (United States)

    Cattiaux, Patrick; Méléard, Sylvie

    2010-06-01

    We are interested in the long time behavior of a two-type density-dependent biological population conditioned on non-extinction, in both cases of competition or weak cooperation between the two species. This population is described by a stochastic Lotka-Volterra system, obtained as limit of renormalized interacting birth and death processes. The weak cooperation assumption allows the system not to blow up. We study the existence and uniqueness of a quasi-stationary distribution, that is convergence to equilibrium conditioned on non-extinction. To this aim we generalize in two-dimensions spectral tools developed for one-dimensional generalized Feller diffusion processes. The existence proof of a quasi-stationary distribution is reduced to the one for a d-dimensional Kolmogorov diffusion process under a symmetry assumption. The symmetry we need is satisfied under a local balance condition relying the ecological rates. A novelty is the outlined relation between the uniqueness of the quasi-stationary distribution and the ultracontractivity of the killed semi-group. By a comparison between the killing rates for the populations of each type and the one of the global population, we show that the quasi-stationary distribution can be either supported by individuals of one (the strongest one) type or supported by individuals of the two types. We thus highlight two different long time behaviors depending on the parameters of the model: either the model exhibits an intermediary time scale for which only one type (the dominant trait) is surviving, or there is a positive probability to have coexistence of the two species.

  20. Standard systems for measurement of pK values and ionic mobilities: 2. Univalent weak bases.

    Science.gov (United States)

    Slampová, Andrea; Krivánková, Ludmila; Gebauer, Petr; Bocek, Petr

    2009-04-24

    This paper contributes to the methodology of measuring pK values and ionic mobilities by capillary zone electrophoresis by introducing the principle of constant ionic strength and minimum interaction of analytes with counterionic components and presenting a standard system of cationic buffers for measurements of weak bases. The system is designed so that all buffers comprise the same concentration of Cl(-) present as the only counter anion. This minimizes problems caused by interactions between the counterion and the analytes which may otherwise bring biased values of obtained effective mobilities. Further, the buffer system provides constant and accurately known ionic strength for an entire set of measurements. When additionally all measurements are performed with constant Joule heating, one correction for ionic strength and temperature is then needed for the obtained set of experimental data. This considerably facilitates their evaluation and regression analysis as the corrections for ionic strength and Joule heating need not be implemented in the computation software and may be applied only once to the final regression results. An experimental example of the proposed methodology is presented and the reliability and the advantages of the proposed system are shown, where the known problematic groups of amines and pyridine were measured with high accuracy and without any notice of anomalous behavior.

  1. [Respiratory system elastance and resistance measured by proportional assist ventilation in patients with respiratory muscle weakness].

    Science.gov (United States)

    Oya, Yasushi; Ogawa, Masafumi; Kawai, Mitsuru

    2004-01-01

    Non-invasive ventilatory therapy has prolonged survival of myopathy patients with hypoventilation. Efficacy of non-invasive ventilation depends on both elastance and resistance of the respiratory system. Although these parameters are important in the prescription of respiratory management, conventional respiratory function test does not show the appropriate answer in patients with severe respiratory muscle weakness. In muscular dystrophy, muscle tends to be shortened due to its fibrosis, when muscle becomes atrophic and weak; fibrosis of respiratory muscle tissues presumably causes high thoracic elastance. We evaluated the total respiratory system elastance and resistance during proportional assist ventilation (PAV) in myopathy patients. In PAV with 100% assist, using BiPAP Vision ventilator, airway pressure exceeds 20 cmH2O or tidal volume exceeds 1.5 liter (run-away phenomenon) when the volume assist or the flow assist is higher than the individual elastance or the resistance, respectively. Twenty myopathy patients with ventilatory failure and 7 healthy controls were evaluated, including 7 patients with Duchenne muscular dystrophy (DMD), 2 patients with congenital myopathy (CM), 1 patient with limb-girdle muscular dystrophy (LG), 6 patients with myotonic dystrophy (MyD) and 4 patients with acid maltase deficiency (AMD). Seventeen patients used a nasal mask and 3 patients had a tracheostomy tube. Fifteen patients used a pressure-preset ventilator, and 3 patients used a volume-preset ventilator. In all patients with DMD, CM and LG, respiratory system elastance was higher than 20 (cmH2O/L) and than in all patients with AMD and MyD except 1 MyD patient. Follow-up measurement after half a or one year showed increase of respiratory system elastance in 2 DMD patients and 1 CM patient, but almost no change in 3 AMD patients. The elastance measured during PAV was consistent with the clinical impression of muscle shortening. One exceptional MyD patient showed extremely

  2. Design optimization of transmitting antennas for weakly coupled magnetic induction communication systems

    Science.gov (United States)

    2017-01-01

    This work focuses on the design of transmitting coils in weakly coupled magnetic induction communication systems. We propose several optimization methods that reduce the active, reactive and apparent power consumption of the coil. These problems are formulated as minimization problems, in which the power consumed by the transmitting coil is minimized, under the constraint of providing a required magnetic field at the receiver location. We develop efficient numeric and analytic methods to solve the resulting problems, which are of high dimension, and in certain cases non-convex. For the objective of minimal reactive power an analytic solution for the optimal current distribution in flat disc transmitting coils is provided. This problem is extended to general three-dimensional coils, for which we develop an expression for the optimal current distribution. Considering the objective of minimal apparent power, a method is developed to reduce the computational complexity of the problem by transforming it to an equivalent problem of lower dimension, allowing a quick and accurate numeric solution. These results are verified experimentally by testing a number of coil geometries. The results obtained allow reduced power consumption and increased performances in magnetic induction communication systems. Specifically, for wideband systems, an optimal design of the transmitter coil reduces the peak instantaneous power provided by the transmitter circuitry, and thus reduces its size, complexity and cost. PMID:28192463

  3. Weak error analysis of approximate simulation methods for multi-scale stochastic chemical kinetic systems

    CERN Document Server

    Anderson, David F

    2011-01-01

    A chemical reaction network is a chemical system involving multiple reactions and chemical species. The simplest stochastic models of such networks treat the system as a continuous time Markov chain with the state being the number of molecules of each species and with reactions modeled as possible transitions of the chain. In this paper we provide a general framework for understanding the weak error of numerical approximation techniques in this setting. For such models, there is typically a wide variation in scales in that the different species and reaction rates vary over several orders of magnitude. Quantifying how different numerical approximation techniques behave in this setting therefore requires that these scalings be taken into account in an appropriate manner. We quantify how the error of different methods depends upon both the natural scalings within a given system, and with the step-size of the numerical method. We show that Euler's method, also called explicit tau-leaping, acts as an order one met...

  4. Planeación de sistemas secundarios de distribución usando el algoritmo Branch and Bound Secondary distribution system planning using branch and bound

    Directory of Open Access Journals (Sweden)

    Ricardo Alberto Hincapie-Isaza

    2011-06-01

    Full Text Available En este trabajo se plantea una metodología para la solución del problema delplaneamiento de sistemas secundarios de distribución considerando un modelode programación lineal entero mixto (PLEM, el cual considera la ubicación y dimensionamiento de transformadores de distribución, el dimensionamientoy rutas de circuitos secundarios y sus costos variables. Para la solución delproblema se emplea el algoritmo Branch and Bound. Los resultados obtenidosen un sistema de prueba empleado en la literatura especializada muestran lavalidez y efectividad de la metodología propuesta.This paper presents a methodology for solving secondary distribution systems planning problem as a mixed integer linear programming problem (MILP. The algorithm takes into account several design issues such as the capacity and location of distribution transformers and secondary feeders. Variable costs of secondary feeders are also considered. The problem is solved using branch and bound algorithm. Numerical results show that the mathematical model and the solution technique are effective for this kind of problems.

  5. Quantum Zeno and anti-Zeno effects in an unstable system with two bound states

    Energy Technology Data Exchange (ETDEWEB)

    Modi, Kavan [Department of Physics, Center for Complex Quantum Systems, University of Texas at Austin, Austin, TX 78712-1081 (United States)], E-mail: modik@physics.utexas.edu; Shaji, Anil [Department of Physics, Center for Complex Quantum Systems, University of Texas at Austin, Austin, TX 78712-1081 (United States)

    2007-08-20

    We analyze the experimental observations reported by Fischer et al. [M.C. Fischer, B. Gutierrez-Medina, M.G. Raizen, Phys. Rev. Lett. 87 (2001) 040402] by considering a system of coupled unstable bound quantum states |A> and |B>. The state |B> is coupled to a set of continuum states |C{theta}({omega})>. We investigate the time evolution of |A> when it decays into |C{theta}({omega})> via |B>, and find that frequent measurements on |A> leads to both the quantum Zeno effect and the anti-Zeno effects depending on the frequency of measurements. We show that it is the presence of |B> which allows for the anti-Zeno effect.

  6. Cramér-Rao bound for time-continuous measurements in linear Gaussian quantum systems

    Science.gov (United States)

    Genoni, Marco G.

    2017-01-01

    We describe a compact and reliable method to calculate the Fisher information for the estimation of a dynamical parameter in a continuously measured linear Gaussian quantum system. Unlike previous methods in the literature, which involve the numerical integration of a stochastic master equation for the corresponding density operator in a Hilbert space of infinite dimension, the formulas here derived depend only on the evolution of first and second moments of the quantum states and thus can be easily evaluated without the need of any approximation. We also present some basic but physically meaningful examples where this result is exploited, calculating analytical and numerical bounds on the estimation of the squeezing parameter for a quantum parametric amplifier and of a constant force acting on a mechanical oscillator in a standard optomechanical scenario.

  7. Existence and asymptotic behavior of positive solutions of a semilinear elliptic system in a bounded domain

    Directory of Open Access Journals (Sweden)

    Majda Chaieb

    2016-01-01

    Full Text Available Let \\(\\Omega\\ be a bounded domain in \\(\\mathbb{R}^{n}\\ (\\(n\\geq 2\\ with a smooth boundary \\(\\partial \\Omega\\. We discuss in this paper the existence and the asymptotic behavior of positive solutions of the following semilinear elliptic system \\[\\begin{aligned} -\\Delta u&=a_{1}(xu^{\\alpha}v^{r}\\quad\\text{in}\\;\\Omega ,\\;\\;\\,u|_{\\partial\\Omega}=0,\\\\ -\\Delta v&=a_{2}(xv^{\\beta}u^{s}\\quad\\text{in}\\;\\Omega ,\\;\\;\\,v|_{\\partial\\Omega }=0.\\end{aligned}\\] Here \\(r,s\\in \\mathbb{R}\\, \\(\\alpha,\\beta \\lt 1\\ such that \\(\\gamma :=(1-\\alpha(1-\\beta-rs\\gt 0\\ and the functions \\(a_{i}\\ (\\(i=1,2\\ are nonnegative and satisfy some appropriate conditions with reference to Karamata regular variation theory.

  8. Weak martingale Hardy spaces and weak atomic decompositions

    Institute of Scientific and Technical Information of China (English)

    HOU; Youliang; REN; Yanbo

    2006-01-01

    In this paper we define some weak martingale Hardy spaces and three kinds of weak atoms. They are the counterparts of martingale Hardy spaces and atoms in the classical martingale Hp-theory. And then three atomic decomposition theorems for martingales in weak martingale Hardy spaces are proved. With the help of the weak atomic decompositions of martingale, a sufficient condition for a sublinear operator defined on the weak martingale Hardy spaces to be bounded is given. Using the sufficient condition, we obtain a series of martingale inequalities with respect to the weak Lp-norm, the inequalities of weak (p ,p)-type and some continuous imbedding relationships between various weak martingale Hardy spaces. These inequalities are the weak versions of the basic inequalities in the classical martingale Hp-theory.

  9. Flight control application of new stability robustness bounds for linear uncertain systems

    Science.gov (United States)

    Yedavalli, Rama K.

    1993-01-01

    This paper addresses the issue of obtaining bounds on the real parameter perturbations of a linear state-space model for robust stability. Based on Kronecker algebra, new, easily computable sufficient bounds are derived that are much less conservative than the existing bounds since the technique is meant for only real parameter perturbations (in contrast to specializing complex variation case to real parameter case). The proposed theory is illustrated with application to several flight control examples.

  10. Dynamic edge warping - An experimental system for recovering disparity maps in weakly constrained systems

    Science.gov (United States)

    Boyer, K. L.; Wuescher, D. M.; Sarkar, S.

    1991-01-01

    Dynamic edge warping (DEW), a technique for recovering reasonably accurate disparity maps from uncalibrated stereo image pairs, is presented. No precise knowledge of the epipolar camera geometry is assumed. The technique is embedded in a system including structural stereopsis on the front end and robust estimation in digital photogrammetry on the other for the purpose of self-calibrating stereo image pairs. Once the relative camera orientation is known, the epipolar geometry is computed and the system can use this information to refine its representation of the object space. Such a system will find application in the autonomous extraction of terrain maps from stereo aerial photographs, for which camera position and orientation are unknown a priori, and for online autonomous calibration maintenance for robotic vision applications, in which the cameras are subject to vibration and other physical disturbances after calibration. This work thus forms a component of an intelligent system that begins with a pair of images and, having only vague knowledge of the conditions under which they were acquired, produces an accurate, dense, relative depth map. The resulting disparity map can also be used directly in some high-level applications involving qualitative scene analysis, spatial reasoning, and perceptual organization of the object space. The system as a whole substitutes high-level information and constraints for precise geometric knowledge in driving and constraining the early correspondence process.

  11. Body posture recognition and turning recording system for the care of bed bound patients.

    Science.gov (United States)

    Hsiao, Rong-Shue; Mi, Zhenqiang; Yang, Bo-Ru; Kau, Lih-Jen; Bitew, Mekuanint Agegnehu; Li, Tzu-Yu

    2015-01-01

    This paper proposes body posture recognition and turning recording system for assisting the care of bed bound patients in nursing homes. The system continuously detects the patient's body posture and records the length of time for each body posture. If the patient remains in the same body posture long enough to develop pressure ulcers, the system notifies caregivers to change the patient's body posture. The objective of recording is to provide the log of body turning for querying of patients' family members. In order to accurately detect patient's body posture, we developed a novel pressure sensing pad which contains force sensing resistor sensors. Based on the proposed pressure sensing pad, we developed a bed posture recognition module which includes a bed posture recognition algorithm. The algorithm is based on fuzzy theory. The body posture recognition algorithm can detect the patient's bed posture whether it is right lateral decubitus, left lateral decubitus, or supine. The detected information of patient's body posture can be then transmitted to the server of healthcare center by the communication module to perform the functions of recording and notification. Experimental results showed that the average posture recognition accuracy for our proposed module is 92%.

  12. Observer-based reliable stabilization of uncertain linear systems subject to actuator faults, saturation, and bounded system disturbances.

    Science.gov (United States)

    Fan, Jinhua; Zhang, Youmin; Zheng, Zhiqiang

    2013-11-01

    A matrix inequality approach is proposed to reliably stabilize a class of uncertain linear systems subject to actuator faults, saturation, and bounded system disturbances. The system states are assumed immeasurable, and a classical observer is incorporated for observation to enable state-based feedback control. Both the stability and stabilization of the closed-loop system are discussed and the closed-loop domain of attraction is estimated by an ellipsoidal invariant set. The resultant stabilization conditions in the form of matrix inequalities enable simultaneous optimization of both the observer gain and the feedback controller gain, which is realized by converting the non-convex optimization problem to an unconstrained nonlinear programming problem. The effectiveness of proposed design techniques is demonstrated through a linearized model of F-18 HARV around an operating point.

  13. A Comparison of Error Bounds for a Nonlinear Tracking System with Detection Probability Pd < 1

    Science.gov (United States)

    Tong, Huisi; Zhang, Hao; Meng, Huadong; Wang, Xiqin

    2012-01-01

    Error bounds for nonlinear filtering are very important for performance evaluation and sensor management. This paper presents a comparative study of three error bounds for tracking filtering, when the detection probability is less than unity. One of these bounds is the random finite set (RFS) bound, which is deduced within the framework of finite set statistics. The others, which are the information reduction factor (IRF) posterior Cramer-Rao lower bound (PCRLB) and enumeration method (ENUM) PCRLB are introduced within the framework of finite vector statistics. In this paper, we deduce two propositions and prove that the RFS bound is equal to the ENUM PCRLB, while it is tighter than the IRF PCRLB, when the target exists from the beginning to the end. Considering the disappearance of existing targets and the appearance of new targets, the RFS bound is tighter than both IRF PCRLB and ENUM PCRLB with time, by introducing the uncertainty of target existence. The theory is illustrated by two nonlinear tracking applications: ballistic object tracking and bearings-only tracking. The simulation studies confirm the theory and reveal the relationship among the three bounds. PMID:23242274

  14. A Comparison of Error Bounds for a Nonlinear Tracking System with Detection Probability Pd < 1

    Directory of Open Access Journals (Sweden)

    Xiqin Wang

    2012-12-01

    Full Text Available Error bounds for nonlinear filtering are very important for performance evaluation and sensor management. This paper presents a comparative study of three error bounds for tracking filtering, when the detection probability is less than unity. One of these bounds is the random finite set (RFS bound, which is deduced within the framework of finite set statistics. The others, which are the information reduction factor (IRF posterior Cramer-Rao lower bound (PCRLB and enumeration method (ENUM PCRLB are introduced within the framework of finite vector statistics. In this paper, we deduce two propositions and prove that the RFS bound is equal to the ENUM PCRLB, while it is tighter than the IRF PCRLB, when the target exists from the beginning to the end. Considering the disappearance of existing targets and the appearance of new targets, the RFS bound is tighter than both IRF PCRLB and ENUM PCRLB with time, by introducing the uncertainty of target existence. The theory is illustrated by two nonlinear tracking applications: ballistic object tracking and bearings-only tracking. The simulation studies confirm the theory and reveal the relationship among the three bounds.

  15. A comparison of error bounds for a nonlinear tracking system with detection probability Pd < 1.

    Science.gov (United States)

    Tong, Huisi; Zhang, Hao; Meng, Huadong; Wang, Xiqin

    2012-12-14

    Error bounds for nonlinear filtering are very important for performance evaluation and sensor management. This paper presents a comparative study of three error bounds for tracking filtering, when the detection probability is less than unity. One of these bounds is the random finite set (RFS) bound, which is deduced within the framework of finite set statistics. The others, which are the information reduction factor (IRF) posterior Cramer-Rao lower bound (PCRLB) and enumeration method (ENUM) PCRLB are introduced within the framework of finite vector statistics. In this paper, we deduce two propositions and prove that the RFS bound is equal to the ENUM PCRLB, while it is tighter than the IRF PCRLB, when the target exists from the beginning to the end. Considering the disappearance of existing targets and the appearance of new targets, the RFS bound is tighter than both IRF PCRLB and ENUM PCRLB with time, by introducing the uncertainty of target existence. The theory is illustrated by two nonlinear tracking applications: ballistic object tracking and bearings-only tracking. The simulation studies confirm the theory and reveal the relationship among the three bounds.

  16. Determining the bounds of skilful forecast range for probabilistic prediction of system-wide wind power generation

    Directory of Open Access Journals (Sweden)

    Dirk Cannon

    2017-06-01

    Full Text Available State-of-the-art wind power forecasts beyond a few hours ahead rely on global numerical weather prediction models to forecast the future large-scale atmospheric state. Often they provide initial and boundary conditions for nested high resolution simulations. In this paper, both upper and lower bounds on forecast range are identified within which global ensemble forecasts provide skilful information for system-wide wind power applications. An upper bound on forecast range is associated with the limit of predictability, beyond which forecasts have no more skill than predictions based on climatological statistics. A lower bound is defined at the lead time beyond which the resolved uncertainty associated with estimating the future large-scale atmospheric state is larger than the unresolved uncertainty associated with estimating the system-wide wind power response to a given large-scale state.The bounds of skilful ensemble forecast range are quantified for three leading global forecast systems. The power system of Great Britain (GB is used as an example because independent verifying data is available from National Grid. The upper bound defined by forecasts of GB-total wind power generation at a specific point in time is found to be 6–8 days. The lower bound is found to be 1.4–2.4 days. Both bounds depend on the global forecast system and vary seasonally. In addition, forecasts of the probability of an extreme power ramp event were found to possess a shorter limit of predictability (4.5–5.5 days. The upper bound on this forecast range can only be extended by improving the global forecast system (outside the control of most users or by changing the metric used in the probability forecast. Improved downscaling and microscale modelling of the wind farm response may act to decrease the lower bound. The potential gain from such improvements have diminishing returns beyond the short-range (out to around 2 days.

  17. Sensitivity analysis of unstable periodic orbits in a weakly chaotic Kuramoto-Sivashinsky system

    Science.gov (United States)

    Lasagna, Davide

    2016-11-01

    Unstable periodic orbits (UPOs) often explain to a remarkable degree of accuracy global statistical features of the turbulent flow in which they are found. In other words, orbital averages, even for short-period UPOs, are good approximation of long-time averages computed over a chaotic, turbulent realisation. Here, we re-examine this property from a design perspective: Does the same degree of approximation exists between the sensitivity of orbital averages with respect to design parameters and the sensitivity of the long-time average itself? Knowledge of this quantity is key in many fundamental design problems involving turbulent flows, most notably in control. In this work, we present an efficient, well conditioned adjoint algorithm derived from specialising well-known variational techniques to the inherent temporal periodicity of UPOs. Once an UPO is available, this algorithm computes the sensitivity of orbital averages with respect to many design parameters at once, regardless of the orbital stability properties. As a demonstration, we analyse the sensitivity to in-domain linear feedback of UPOs found for the Kuramoto-Sivashinsky system in a weakly chaotic regime.

  18. Ability to detect weak effective seismic signals by utilizing chaotic vibrator system

    Institute of Scientific and Technical Information of China (English)

    LI Yue; YANG Baojun; YUAN Ye; ZHAO Xueping; LIN Hongbo

    2006-01-01

    Taking the advantage of CVS (Chaotic Vibrator System) sensitivity of large-scale periodic phase-state response to quasi-periodic or periodic signals, a series of numerical experiments were made to understand the ability of CVS to detect weak effective seismic signals in the common-shot seismic record distorted by strong stochastic noise. The results demonstrate that the large-scale periodic phase-states of CVS are correlated with the signal composition of the quasi-periodic wavelet sequence constructing from horizontal moveout of seismic events, noise strength and the noise distortion degree to signal. For the same kind of events, the higher the noise distortion degree is, the lower the detectable SNR can be reached by CVS. For seismic data with the same noise distortion degree, the closer the scanning seismic velocity (the trial moveout velocity) approaches to the accurate velocity, the higher the detectable SNR can be reached by CVS. Moreover, the truncating scanning velocities form an asymmetric belt, which indirectly makes CVS achieve a large-scale periodic phase-state and then the ratio of wavelet distortion coefficients in events can be a biggish variable scope.

  19. Applications of exact linearization techniques for steady-state stability enhancement in a weak ac/dc system

    Energy Technology Data Exchange (ETDEWEB)

    Kaprielian, S.; Clements, K. (Dept. of Electrical Engineering, Worcester Polytechnic Inst., Worcester, MA (US)); Turi, J. (Texas Univ., Richardson, TX (United States))

    1992-05-01

    A nonlinear control strategy to improve the steady-state stability of a weak AC/DC power system is presented. The approach described in this paper is based on the extension of feedback linearization techniques to nonlinear descriptor system models. This method produces a nonlinear control strategy which is capable of enhancing system performance for various system operating conditions. This claim is supported with simulation results.

  20. Semiclassical dynamics of a bound system in a high-frequency field

    Energy Technology Data Exchange (ETDEWEB)

    Brenner, N.; Fishman, S. [Dept. of Phys., Technion-Israel Inst. of Technol., Haifa (Israel)

    1995-11-07

    The quantal behaviour of a particle in a one-dimensional triangular potential well, driven by a monochromatic electric field, is studied. A classical high-frequency expansion together with semiclassical uniform methods are used to obtain an explicit form of the Floquet evolution operator in the unperturbed basis. A local exact solution is found for the eigenvalue equation of this operator under certain conditions. The local solution provides a tool for the quantitative investigation of the eigenstates. It predicts the appearance of quasi-resonances, or photonic states, and gives their location, shape and width as a function of parameters. It also predicts a local crossover from a decaying region to a more extended region as a function of n, with a point of crossover n{sub c} between them. The results concerning the local structures are used to justify and extend a previously suggested method for the investigation of the asymptotic properties of the eigenstates. These are found to decay with a power depending on the field parameters (first proposed by Benvenuto et al., 1991). The specific system studied here is suggested as a prototype model for a class of driven one-dimensional bound systems. Whose main characteristic is an increasing density of states as a function of energy. (author)

  1. Stability of linear switched systems with quadratic bounds and Observability of bilinear systems

    CERN Document Server

    Balde, Moussa

    2012-01-01

    The aim of this paper is to give sufficient conditions for a switched linear system defined by a pair of Hurwitz matrices that share a common but not strict quadratic Lyapunov function to be GUAS. We show that this property is equivalent to the uniform observability of a bilinear system defined on a subspace whose dimension is in most cases much smaller than the dimension of the switched system. Some sufficient conditions of uniform asymptotic stability are then deduced from the equivalence theorem, and illustrated by examples.

  2. Highly Efficient Design of DSP Systems Using Electronic Design Automation Tool to Find Iteration Bound

    Directory of Open Access Journals (Sweden)

    G. S. Satish Kumar

    2012-09-01

    Full Text Available Digital signal processing algorithms are repetitive in nature. These algorithms are described by iterative data flow graph (DFG where nodes represent tasks and edges represent communication. Execution of all nodes of the DFG once completes iteration. Successive iteration of any node are executive with a time displacement referred to as the iteration period. For all recursive signal processing algorithms, there exists an inherent fundamental lower bound on the iteration period referred to as the iteration period bound or the iteration period. This bound is fundamental to an algorithm and is independent of the implementation architecture. In other words it is impossible to achieve an iteration period less than the bound even when infinite processors are available to execute the recursive algorithm. Iteration bound need to be determined in rate-optimal scheduling of iterative data flow graph. The iteration bound determination has to pre-order repeatedly in the scheduling phase of the high level synthesis. In recursive constrained scheduling a given processing algorithm is scheduled to achieve the minimum iteration period using the given hardware resources. In order to execute operation of the processing algorithm in parallel, the required number of processors or functional units required to execute the operation in parallel may be larger than the number of available resources. Generally the precedence to be assigned is not unique. Hence the iteration bound should be determined for every possible precedence to check which precedence leads to the final schedule with the minimum iteration period. Consequently the iteration bound may have to be computed many times and it is important to determine the iteration bound in minimum possible time.

  3. Bound entanglement and entanglement bounds

    Energy Technology Data Exchange (ETDEWEB)

    Sauer, Simeon [Physikalisch-Astronomische Fakultaet, Friedrich-Schiller-Univesitaet Jena (Germany)]|[Physikalisches Institut, Albert-Ludwigs-Universitaet Freiburg, Hermann-Herder-Strasse 3, D-79104 Freiburg (Germany); Melo, Fernando de; Mintert, Florian; Buchleitner, Andreas [Physikalisches Institut, Albert-Ludwigs-Universitaet Freiburg, Hermann-Herder-Strasse 3, D-79104 Freiburg (Germany)]|[Max-Planck-Institut fuer Physik komplexer Systeme, Noethnitzer Str.38, D-01187 Dresden (Germany); Bae, Joonwoo [School of Computational Sciences, Korea Institute for Advanced Study, Seoul 130-012 (Korea); Hiesmayr, Beatrix [Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna (Austria)

    2008-07-01

    We investigate the separability of Bell-diagonal states of two qutrits. By using lower bounds to algebraically estimate concurrence, we find convex regions of bound entangled states. Some of these regions exactly coincide with the obtained results when employing optimal entanglement witnesses, what shows that the lower bound can serve as a precise detector of entanglement. Some hitherto unknown regions of bound entangled states were discovered with this approach, and delimited efficiently.

  4. Towards an integrated forecasting system for fisheries on habitat-bound stocks

    Directory of Open Access Journals (Sweden)

    A. Christensen

    2013-03-01

    Full Text Available First results of a coupled modelling and forecasting system for fisheries on habitat-bound stocks are being presented. The system consists currently of three mathematically, fundamentally different model subsystems coupled offline: POLCOMS providing the physical environment implemented in the domain of the north-west European shelf, the SPAM model which describes sandeel stocks in the North Sea, and the third component, the SLAM model, which connects POLCOMS and SPAM by computing the physical–biological interaction. Our major experience by the coupling model subsystems is that well-defined and generic model interfaces are very important for a successful and extendable coupled model framework. The integrated approach, simulating ecosystem dynamics from physics to fish, allows for analysis of the pathways in the ecosystem to investigate the propagation of changes in the ocean climate and to quantify the impacts on the higher trophic level, in this case the sandeel population, demonstrated here on the basis of hindcast data. The coupled forecasting system is tested for some typical scientific questions appearing in spatial fish stock management and marine spatial planning, including determination of local and basin-scale maximum sustainable yield, stock connectivity and source/sink structure. Our presented simulations indicate that sandeel stocks are currently exploited close to the maximum sustainable yield, even though periodic overfishing seems to have occurred, but large uncertainty is associated with determining stock maximum sustainable yield due to stock inherent dynamics and climatic variability. Our statistical ensemble simulations indicates that the predictive horizon set by climate interannual variability is 2–6 yr, after which only an asymptotic probability distribution of stock properties, like biomass, are predictable.

  5. On the Inviscid Limit for the Compressible Navier-Stokes System in an Impermeable Bounded Domain

    Science.gov (United States)

    Sueur, Franck

    2014-03-01

    In this paper we investigate the issue of the inviscid limit for the compressible Navier-Stokes system in an impermeable fixed bounded domain. We consider two kinds of boundary conditions. The first one is the no-slip condition. In this case we extend the famous conditional result (Kato, T.: Remarks on zero viscosity limit for nonstationary Navier-Stokes flows with boundary. In: Seminar on nonlinear partial differential equations, vol. 2, pp. 85-98. Math. Sci. Res. Inst. Publ., Berkeley 1984) obtained by Kato in the homogeneous incompressible case. Kato proved that if the energy dissipation rate of the viscous flow in a boundary layer of width proportional to the viscosity vanishes then the solutions of the incompressible Navier-Stokes equations converge to some solutions of the incompressible Euler equations in the energy space. We provide here a natural extension of this result to the compressible case. The other case is the Navier condition which encodes that the fluid slips with some friction on the boundary. In this case we show that the convergence to the Euler equations holds true in the energy space, as least when the friction is not too large. In both cases we use in a crucial way some relative energy estimates proved recently by Feireisl et al. in J. Math. Fluid Mech. 14:717-730 (2012).

  6. Solutions to the Einstein-scalar-field system in spherical symmetry with large bounded variation norms

    CERN Document Server

    Luk, Jonathan; Yang, Shiwu

    2016-01-01

    It is well-known that small, regular, spherically symmetric characteristic initial data to the Einstein-scalar-field system which are decaying towards (future null) infinity give rise to solutions which are foward-in-time global (in the sense of future causal geodesic completeness). We construct a class of spherically symmetric solutions which are global but the initial norms are consistent with initial data not decaying towards infinity. This gives the following consequences: (1) We prove that there exist foward-in-time global solutions with arbitrarily large (and in fact infinite) initial bounded variation (BV) norms and initial Bondi masses. (2) While general solutions with non-decaying data do not approach Minkowski spacetime, we show using the results of Luk--Oh that if a sufficiently strong asymptotic flatness condition is imposed on the initial data, then the solutions we construct (with large BV norms) approach Minkowski spacetime with a sharp inverse polynomial rate. (3) Our construction can be easil...

  7. On the inviscid limit for the compressible Navier-Stokes system in an impermeable bounded domain

    CERN Document Server

    Sueur, Franck

    2012-01-01

    In this paper we investigate the issue of the inviscid limit for the compressible Navier-Stokes system in an impermeable fixed bounded domain. We consider two kinds of boundary conditions. The first one is the no-slip condition. In this case we extend the famous conditional result obtained by Kato in the homogeneous incompressible case. Kato proved that if the energy dissipation rate of the viscous flow in a boundary layer of width proportional to the viscosity vanishes then the solutions of the incompressible Navier-Stokes equations converge to some solutions of the incompressible Euler equations in the energy space. We provide here a natural extension of this result to the compressible case. The other case is the Navier condition which encodes that the fluid slips with some friction on the boundary. In this case we show that the convergence to the Euler equations holds true in the energy space, as least when the friction is not too large. In both cases we use in a crucial way some relative energy estimates ...

  8. Robust Consensus of Nonlinear Multiagent Systems With Switching Topology and Bounded Noises.

    Science.gov (United States)

    Chen, Yao; Dong, Hairong; Lu, Jinhu; Sun, Xubin; Liu, Kexin

    2016-06-01

    Consensus of multiagent systems (MASs) is an intriguing topic in recent years due to its widely used application in robotics, biology, computer, and social science. In the real world, the evolution of MAS is inevitably involved in dynamical environments and the recent development of MAS calls for novel tools for the analysis of MAS with dynamic topology. In addition, the interactions between agents are generally nonlinear and environmental noises are ubiquitous in the communication channels between agents. However, the existing investigation on MAS places little attention on nonlinear models and the inner relationship between external disturbance and consensus is still unclear. Facing these problems, this paper considers an MAS in which the interactions between agents are nonlinear and the communication between agents are infected by environmental noises. By using a novel method of nonsmooth Lyapunov candidate, it has been demonstrated that such an MAS can realize robust consensus under the conditions of jointly (sequentially) connected topology and bounded noises. Finally, simulation results validate the effectiveness of these criteria.

  9. Verifying the error bound of numerical computation implemented in computer systems

    Science.gov (United States)

    Sawada, Jun

    2013-03-12

    A verification tool receives a finite precision definition for an approximation of an infinite precision numerical function implemented in a processor in the form of a polynomial of bounded functions. The verification tool receives a domain for verifying outputs of segments associated with the infinite precision numerical function. The verification tool splits the domain into at least two segments, wherein each segment is non-overlapping with any other segment and converts, for each segment, a polynomial of bounded functions for the segment to a simplified formula comprising a polynomial, an inequality, and a constant for a selected segment. The verification tool calculates upper bounds of the polynomial for the at least two segments, beginning with the selected segment and reports the segments that violate a bounding condition.

  10. Lung volume recruitment acutely increases respiratory system compliance in individuals with severe respiratory muscle weakness

    Directory of Open Access Journals (Sweden)

    Yannick Molgat-Seon

    2017-03-01

    Full Text Available The aim of the present study was to determine whether lung volume recruitment (LVR acutely increases respiratory system compliance (Crs in individuals with severe respiratory muscle weakness (RMW. Individuals with RMW resulting from neuromuscular disease or quadriplegia (n=12 and healthy controls (n=12 underwent pulmonary function testing and the measurement of Crs at baseline, immediately after, 1 h after and 2 h after a single standardised session of LVR. The LVR session involved 10 consecutive supramaximal lung inflations with a manual resuscitation bag to the highest tolerable mouth pressure or a maximum of 50 cmH2O. Each LVR inflation was followed by brief breath-hold and a maximal expiration to residual volume. At baseline, individuals with RMW had lower Crs than controls (37±5 cmH2O versus 109±10 mL·cmH2O−1, p0.05. LVR had no significant effect on measures of pulmonary function at any time point in either group (all p>0.05. During inflations, mean arterial pressure decreased significantly relative to baseline by 10.4±2.8 mmHg and 17.3±3.0 mmHg in individuals with RMW and controls, respectively (both p<0.05. LVR acutely increases Crs in individuals with RMW. However, the high airway pressures during inflations cause reductions in mean arterial pressure that should be considered when applying this technique.

  11. Physical Uncertainty Bounds (PUB)

    Energy Technology Data Exchange (ETDEWEB)

    Vaughan, Diane Elizabeth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Preston, Dean L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-03-19

    This paper introduces and motivates the need for a new methodology for determining upper bounds on the uncertainties in simulations of engineered systems due to limited fidelity in the composite continuum-level physics models needed to simulate the systems. We show that traditional uncertainty quantification methods provide, at best, a lower bound on this uncertainty. We propose to obtain bounds on the simulation uncertainties by first determining bounds on the physical quantities or processes relevant to system performance. By bounding these physics processes, as opposed to carrying out statistical analyses of the parameter sets of specific physics models or simply switching out the available physics models, one can obtain upper bounds on the uncertainties in simulated quantities of interest.

  12. Upper Bounds for the Distance between a Controllable Switched Linear System and the Set of Uncontrollable Ones

    Directory of Open Access Journals (Sweden)

    Josep Clotet

    2013-01-01

    Full Text Available The set of controllable switched linear systems is an open and dense set in the space of all switched linear systems. Therefore it makes sense to compute the distance from a controllable system to the nearest uncontrollable one. In the case of a standard system, x˙t=Axt+But, R. Eising, D. Boley, and W. S. Lu obtain some results for this distance, both in the complex and real cases. In this work we explore this distance, for switched linear systems in the real case, obtaining upper bounds for it. The main contribution of the paper is to prove that a natural generalization of the upper bound obtained by D. Boley and W. S. Lu is true in the case of switched linear systems.

  13. Weak Convergence and Weak Convergence

    Directory of Open Access Journals (Sweden)

    Narita Keiko

    2015-09-01

    Full Text Available In this article, we deal with weak convergence on sequences in real normed spaces, and weak* convergence on sequences in dual spaces of real normed spaces. In the first section, we proved some topological properties of dual spaces of real normed spaces. We used these theorems for proofs of Section 3. In Section 2, we defined weak convergence and weak* convergence, and proved some properties. By RNS_Real Mizar functor, real normed spaces as real number spaces already defined in the article [18], we regarded sequences of real numbers as sequences of RNS_Real. So we proved the last theorem in this section using the theorem (8 from [25]. In Section 3, we defined weak sequential compactness of real normed spaces. We showed some lemmas for the proof and proved the theorem of weak sequential compactness of reflexive real Banach spaces. We referred to [36], [23], [24] and [3] in the formalization.

  14. Renormalization and Central limit theorem for critical dynamical systems with weak external noise

    CERN Document Server

    Diaz-Espinosa, O

    2006-01-01

    We study of the effect of weak noise on critical one dimensional maps; that is, maps with a renormalization theory. We establish a one dimensional central limit theorem for weak noises and obtain Berry--Esseen estimates for the rate of this convergence. We analyze in detail maps at the accumulation of period doubling and critical circle maps with golden mean rotation number. Using renormalization group methods, we derive scaling relations for several features of the effective noise after long times. We use these scaling relations to show that the central limit theorem for weak noise holds in both examples. We note that, for the results presented here, it is essential that the maps have parabolic behavior. They are false for hyperbolic orbits.

  15. The Existence of Weak D-Pullback Exponential Attractor for Nonautonomous Dynamical System.

    Science.gov (United States)

    Li, Yongjun; Wei, Xiaona; Zhang, Yanhong

    2016-01-01

    First, for a process {U(t, τ)∣t ≥ τ}, we introduce a new concept, called the weak D-pullback exponential attractor, which is a family of sets {ℳ(t)∣t ≤ T}, for any T ∈ ℝ, satisfying the following: (i) ℳ(t) is compact, (ii) ℳ(t) is positively invariant, that is, U(t, τ)ℳ(τ) ⊂ ℳ(t), and (iii) there exist k, l > 0 such that dist(U(t, τ)B(τ), ℳ(t)) ≤ ke (-(t-τ)); that is, ℳ(t) pullback exponential attracts B(τ). Then we give a method to obtain the existence of weak D-pullback exponential attractors for a process. As an application, we obtain the existence of weak D-pullback exponential attractor for reaction diffusion equation in H 0 (1) with exponential growth of the external force.

  16. The Existence of Weak D-Pullback Exponential Attractor for Nonautonomous Dynamical System

    Directory of Open Access Journals (Sweden)

    Yongjun Li

    2016-01-01

    Full Text Available First, for a process U(t,τ∣t≥τ, we introduce a new concept, called the weak D-pullback exponential attractor, which is a family of sets M(t∣t≤T, for any T∈R, satisfying the following: (i M(t is compact, (ii M(t is positively invariant, that is, U(t,τM(τ⊂M(t, and (iii there exist k,l>0 such that dist(U(t,τB(τ,M(t≤ke-(t-τ; that is, M(t pullback exponential attracts B(τ. Then we give a method to obtain the existence of weak D-pullback exponential attractors for a process. As an application, we obtain the existence of weak D-pullback exponential attractor for reaction diffusion equation in H01 with exponential growth of the external force.

  17. A Chinese literature overview on ultra-weak photon emission as promising technology for studying system-based diagnostics

    NARCIS (Netherlands)

    He, M.; Sun, M.; Wijk, E. van; Wietmarschen, H. van; Wijk, R. van; Wang, Z.; Wang, M.; Hankemeier, T.; Greef, J. van der

    2016-01-01

    To present the possibilities pertaining to linking ultra-weak photon emission (UPE) with Chinese medicine-based diagnostics principles, we conducted a review of Chinese literature regarding UPE with respect to a systems view of diagnostics. Data were summarized from human clinical studies and animal

  18. The Smoothness of Weak Solutions to the System of Second Order Differential Equations with Non—negative Characteristics

    Institute of Scientific and Technical Information of China (English)

    张克农

    1993-01-01

    In this paper,we will discuss smoothness of weak solutions for the system of second order differential cquations eith non-negative characteristics.First of all,we establish boundary and interior estimates and then we prove that solutions of regularization problem satisfy Lipschitz condition.

  19. STATIONARY STRUCTURES FOR A WEAKLY COUPLED ELLIPTIC SYSTEM ARISING IN TWO-PREDATOR, TWO-PREY MODELS

    Institute of Scientific and Technical Information of China (English)

    严平; 林支桂

    2001-01-01

    Weakly-coupled elliptic system arising in the two-predator, two-prey model is discussed. It is proved that there is no non-constant solution if diffusions or inter-specific competitions are strong, or if the intrinsic growths of the prey are slow and the intrinsic drop rates of predator are fast.

  20. GLOBAL WEAKLY DISCONTINUOUS SOLUTIONS TO A KIND OF MIXED INITIAL-BOUNDARY VALUE PROBLEM FOR INHOMOGENEOUS QUASILINEAR HYPERBOLIC SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    GUO Fei

    2007-01-01

    In this paper we study the mixed initial-boundary value problem for inhomogeneous quasilinear hyperbolic systems in the domain D={(t,x)| t≥O,x≥O}.Under the assumption that the source term satisfies the matching condition,a sufficient condition to guarantee the existence and uniqueness of global weakly discontinuous solution is given.

  1. New Integral Inequalities with Weakly Singular Kernel for Discontinuous Functions and Their Applications to Impulsive Fractional Differential Systems

    Directory of Open Access Journals (Sweden)

    Jing Shao

    2014-01-01

    Full Text Available Some new integral inequalities with weakly singular kernel for discontinuous functions are established using the method of successive iteration and properties of Mittag-Leffler function, which can be used in the qualitative analysis of the solutions to certain impulsive fractional differential systems.

  2. Toward quantifying metrics for rail-system resilience: Identification and analysis of performance weak-resilience-signals

    NARCIS (Netherlands)

    de Regt, A.; Siegel, A.W.; Schraagen, Johannes Martinus Cornelis

    2016-01-01

    This paper aims to enhance tangibility of the resilience engineering concept by facilitating understanding and operationalization of weak-resilience-signals (WRS) in the rail sector. Within complex socio-technical systems, accidents can be seen as unwanted outcomes emerging from uncontrolled sources

  3. Analyticity of Essentially Bounded Solutions to Semilinear Parabolic Systems and Validity of the Ginzburg-Landau Equation

    NARCIS (Netherlands)

    A. Doelman; P. Takác; P. Bollerman; A. van Harten; E.S. Titi

    1996-01-01

    Some analytic smoothing properties of a general strongly coupled, strongly parabolic semilinear system of order $2m$ in $realnos^D times (0,T)$ with analytic entries are investigated. These properties are expressed in terms of holomorphic continuation in space and time of essentially bounded global

  4. UNIQUENESS AND DISTRIBUTION OF LIMIT CYCLES FOR BOUNDED QUADRATIC SYSTEM%有界二次系统极限环的唯一性及分布

    Institute of Scientific and Technical Information of China (English)

    宋矞

    2001-01-01

    In this paper, we first give a necessary and sufficient condition of a quadratic system with three finite critical points being bounded, and then, we use the methods and conclusions of [11] to provide some uniqueness theorems of limit cycles for bounded quadratic systems. As well, we prove that any bounded quadratic system can not have (2, 2)-distribution of limit cycles according to these uniqueness theorems.

  5. On Entropy Bounds and Holography

    CERN Document Server

    Halyo, Edi

    2009-01-01

    We show that the holographic entropy bound for gravitational systems and the Bekenstein entropy bound for nongravitational systems are holographically related. Using the AdS/CFT correspondence, we find that the Bekenstein bound on the boundary is obtained from the holographic bound in the bulk by minimizing the boundary energy with respect the AdS radius or the cosmological constant. This relation may also ameliorate some problems associated with the Bekenstein bound.

  6. Estimation problem for impulsive control systems under ellipsoidal state bounds and with cone constraint on the control

    Science.gov (United States)

    Matviychuk, Oksana G.

    2012-11-01

    The paper deals with the state estimation problem for the linear control system containing impulsive control terms (or measures). The problem is studied here under uncertainty conditions when the initial system state is unknown but bounded, with given bound. It is assumed also that the system states should belong to the given ellipsoid in the state space. So the main problem of estimating the reachable set of the control system is studied here under more complicated assumption related to the case of state constraints. It is assumed additionally that impulsive controls in the dynamical system must belong to the intersection of a special cone with a generalized ellipsoid both taken in the space of functions of bounded variation. The last constraint is motivated by problems of impulsive control theory and by models from applied areas when not every direction of control impulses is acceptable in the system. We present here the state estimation algorithms that use the special structure of the control system and take into account additional restrictions on states and controls. The algorithms are based on ellipsoidal techniques for estimating the trajectory tubes of uncertain dynamical systems. Numerical simulation results related to proposed procedures are also given.

  7. Fracture distribution and porosity in a fault-bound hydrothermal system (Grimsel Pass, Swiss Alps)

    Science.gov (United States)

    Egli, Daniel; Küng, Sulamith; Baumann, Rahel; Berger, Alfons; Baron, Ludovic; Herwegh, Marco

    2017-04-01

    The spatial distribution, orientation and continuity of brittle and ductile structures strongly control fluid pathways in a rock mass by joining existing pores and creating new pore space (fractures, joints) but can also act as seals to fluid flow (e.g. ductile shear zones, clay-rich fault gouges). In long-lived hydrothermal systems, permeability and the related fluid flow paths are therefore dynamic in space and time. Understanding the evolution and behaviour of naturally porous and permeable rock masses is critical for the successful exploration and sustainable exploitation of hydrothermal systems and can advance methods for planning and implementation of enhanced geothermal systems. This study focuses on an active fault-bound hydrothermal system in the crystalline basement of the Aar Massif (hydrothermal field Grimsel Pass, Swiss Alps) that has been exhumed from few kilometres depth and which documents at least 3 Ma of hydrothermal activity. The explored rock unit of the Aar massif is part of the External Crystalline Massifs that hosts a multitude of thermal springs on its southern border in the Swiss Rhône valley and furthermore represents the exhumed equivalent of potentially exploitable geothermal reservoirs in the deep crystalline subsurface of the northern Alpine foreland basin. This study combines structural data collected from a 125 m long drillhole across the hydrothermal zone, the corresponding drill core and surface mapping. Different methods are applied to estimate the porosity and the structural evolution with regard to porosity, permeability and fracture distribution. Analyses are carried out from the micrometre to decametre scale with main focus on the flow path evolution with time. This includes a large variety of porosity-types including fracture-porosity with up to cm-sized aperture down to grain-scale porosity. Main rock types are granitoid host rocks, mylonites, paleo-breccia and recent breccias. The porosity of the host rock as well as the

  8. Weak solutions to the Landau-Lifshitz-Maxwell system with nonlinear Neumann boundary conditions arising from surface energies

    Directory of Open Access Journals (Sweden)

    Gilles Carbou

    2015-02-01

    Full Text Available We study the Landau-Lifshitz system associated with Maxwell equations in a bilayered ferromagnetic body when super-exchange and surface anisotropy interactions are present in the spacer in-between the layers. In the presence of these surface energies, the Neumann boundary condition becomes nonlinear. We prove, in three dimensions, the existence of global weak solutions to the Landau-Lifshitz-Maxwell system with nonlinear Neumann boundary conditions.

  9. Quantum Transport through a Triple Quantum Dot System in the Presence of Majorana Bound States

    Science.gov (United States)

    Jiang, Zhao-Tan; Cao, Zhi-Yuan; Zhong, Cheng-Cheng

    2016-05-01

    We study the electron transport through a special quantum-dot (QD) structure composed of three QDs and two Majorana bound states (MBSs) using the nonequilibrium Green's function technique. This QD-MBS ring structure includes two channels with the two coupled MBSs being Channel 1 and one QD being Channel 2, and three types of transport processes such as the electron transmission (ET), the Andreev reflection (AR), and the crossed Andreev reflection (CAR). By comparing the ET, AR, and CAR processes through Channels 1 and 2, we make a systematic study on the transport properties of the QD-MBS ring. It is shown that there appear two kinds of characteristic transport patterns for Channels 1 and 2, as well as the interplay between the two patterns. Of particular interest is that there exists an AR-assisted ET process in Channel 2, which is different from that in Channel 1. Thus a clear “X” pattern due to the ET and AR processes appears in the ET, AR, and CAR transmission coefficients. Moreover, we study how Channel 2 affects the three transport processes when Channel 1 is tuned in the ET and CAR regimes. It is shown that the transport properties of the ET, AR and CAR processes can be adjusted by tuning the energy level of the QD embedded in Channel 2. We believe this research should be a helpful reference for understanding the transport properties in the QD-MBS coupled systems. Supported by National Natural Science Foundation of China under Grant No. 11274040, and by the Program for New Century Excellent Talents in University under Grant No. NCET-08-0044

  10. Decentralised robust stabilisation of uncertain large-scale interconnected time-delay systems with unknown upper bounds of uncertainties

    Science.gov (United States)

    Wu, Hansheng

    2016-09-01

    The problem of decentralised robust stabilisation is considered for a class of uncertain large-scale time-delay interconnected dynamical systems. In the paper, the upper bounds of delayed state perturbations, uncertainties, interconnection terms, and external disturbances are assumed to be completely unknown, and the delays are assumed to be any non-negative constants. For such a class of uncertain large-scale time-delay interconnected systems, a new method is presented whereby a class of adaptation-free decentralised local robust state feedback controllers can be constructed. In addition, it is also shown that the solutions of uncertain large-scale time-delay interconnected systems can be guaranteed to be uniformly ultimately bounded. Finally, as an application to the practical mechanical systems, some simulations of a numerical example are provided to demonstrate the validity of the theoretical results.

  11. Diffusion induced by bounded noise in a two-dimensional coupled memory system

    Directory of Open Access Journals (Sweden)

    Pengfei Xu

    2014-01-01

    Full Text Available The diffusion behavior driven by bounded noise under the influence of a coupled harmonic potential is investigated in a two-dimensional coupled-damped model. With the help of the Laplace analysis we obtain exact descriptions for a particle's two-time dynamics which is subjected to a coupled harmonic potential and a coupled damping. The time lag is used to describe the velocity autocorrelation function and mean square displacement of the diffusing particle. The diffusion behavior for the time lag is also discussed with respect to the coupled items and the amplitude of bounded noise.

  12. Optical linewidths of Frenkel excitons in weakly disordered three-dimensional systems

    Science.gov (United States)

    Boukahil, A.; Huber, D. L.

    1991-10-01

    A calculation of the optical linewidth of a Frenkel exciton in a weakly disordered, three-dimensional array is presented. The disorder is reflected in a random distribution of transition frequencies with variance σ 2. An analysis based on the coherent potential approximation leads to a linewidth proportional to σ 3. The predictions of the theory are in quantitative agreement with the numerical simulation data of Schreiber and Toyozawa.

  13. Uniform Regularity and Vanishing Dissipation Limit for the Full Compressible Navier-Stokes System in Three Dimensional Bounded Domain

    Science.gov (United States)

    Wang, Yong

    2016-09-01

    In the present paper, we study the uniform regularity and vanishing dissipation limit for the full compressible Navier-Stokes system whose viscosity and heat conductivity are allowed to vanish at different orders. The problem is studied in a three dimensional bounded domain with Navier-slip type boundary conditions. It is shown that there exists a unique strong solution to the full compressible Navier-Stokes system with the boundary conditions in a finite time interval which is independent of the viscosity and heat conductivity. The solution is uniformly bounded in {W^{1,infty}} and is a conormal Sobolev space. Based on such uniform estimates, we prove the convergence of the solutions of the full compressible Navier-Stokes to the corresponding solutions of the full compressible Euler system in {L^infty(0,T; L^2)}, {L^infty(0,T; H1)} and {L^infty([0,T]×Ω)} with a rate of convergence.

  14. Bounding the role of black carbon in the climate system: A scientific assessment

    Science.gov (United States)

    Bond, T. C.; Doherty, S. J.; Fahey, D. W.; Forster, P. M.; Berntsen, T.; Deangelo, B. J.; Flanner, M. G.; Ghan, S.; KäRcher, B.; Koch, D.; Kinne, S.; Kondo, Y.; Quinn, P. K.; Sarofim, M. C.; Schultz, M. G.; Schulz, M.; Venkataraman, C.; Zhang, H.; Zhang, S.; Bellouin, N.; Guttikunda, S. K.; Hopke, P. K.; Jacobson, M. Z.; Kaiser, J. W.; Klimont, Z.; Lohmann, U.; Schwarz, J. P.; Shindell, D.; Storelvmo, T.; Warren, S. G.; Zender, C. S.

    2013-06-01

    carbon aerosol plays a unique and important role in Earth's climate system. Black carbon is a type of carbonaceous material with a unique combination of physical properties. This assessment provides an evaluation of black-carbon climate forcing that is comprehensive in its inclusion of all known and relevant processes and that is quantitative in providing best estimates and uncertainties of the main forcing terms: direct solar absorption; influence on liquid, mixed phase, and ice clouds; and deposition on snow and ice. These effects are calculated with climate models, but when possible, they are evaluated with both microphysical measurements and field observations. Predominant sources are combustion related, namely, fossil fuels for transportation, solid fuels for industrial and residential uses, and open burning of biomass. Total global emissions of black carbon using bottom-up inventory methods are 7500 Gg yr-1 in the year 2000 with an uncertainty range of 2000 to 29000. However, global atmospheric absorption attributable to black carbon is too low in many models and should be increased by a factor of almost 3. After this scaling, the best estimate for the industrial-era (1750 to 2005) direct radiative forcing of atmospheric black carbon is +0.71 W m-2 with 90% uncertainty bounds of (+0.08, +1.27) W m-2. Total direct forcing by all black carbon sources, without subtracting the preindustrial background, is estimated as +0.88 (+0.17, +1.48) W m-2. Direct radiative forcing alone does not capture important rapid adjustment mechanisms. A framework is described and used for quantifying climate forcings, including rapid adjustments. The best estimate of industrial-era climate forcing of black carbon through all forcing mechanisms, including clouds and cryosphere forcing, is +1.1 W m-2 with 90% uncertainty bounds of +0.17 to +2.1 W m-2. Thus, there is a very high probability that black carbon emissions, independent of co-emitted species, have a positive forcing and warm

  15. Weak Force

    CERN Multimedia

    Without the weak force, the sun wouldn't shine. The weak force causes beta decay, a form of radioactivity that triggers nuclear fusion in the heart of the sun. The weak force is unlike other forces: it is characterised by disintegration. In beta decay, a down quark transforms into an up quark and an electron is emitted. Some materials are more radioactive than others because the delicate balance between the strong force and the weak force varies depending on the number of particles in the atomic nucleus. We live in the midst of a natural radioactive background that varies from region to region. For example, in Cornwall where there is a lot of granite, levels of background radiation are much higher than in the Geneva region. Text for the interactive: Move the Geiger counter to find out which samples are radioactive - you may be surprised. It is the weak force that is responsible for the Beta radioactivity here. The electrons emitted do not cross the plastic cover. Why do you think there is some detected radioa...

  16. Disaster Management System of Iran--Need to Eliminate Weaknesses and Problems

    Directory of Open Access Journals (Sweden)

    H Seyedin

    2005-10-01

    Full Text Available Background: Iran has been a very disaster-prone country throughout its history. Wars, earthquakes, floods, droughts, inversion effects of air pollution in metropolitan have occurred many times, affected millions of people, and have claimed hundred thousands of lives during past century. Recently the fatal earthquake of Bam claimed more than 30000 lives and many casualties and economic lost, while in USA, a similar earthquake just killed 2 people and damaged much less. This may raise a fundamental question in our mind: why do disasters in developed countries cause the least amount of damages while in developing countries such Iran in the same situation the most indemnity? Methodology: This research aimed at studying existing Disaster Management System (DMS in Iran and illuminating weaknesses during a crisis using a survey and reviewing the literature on DMS in developed and developing countries. Results and Discussion: In Iran, disaster management is managed by National Committee for Natural Disaster Management, which is located in Ministry of Interior. When the National Disaster Management Organization (NDMO is located in a line ministry, it may not be able to guarantee the representation and participation of the other line ministries. Considering our culture and annually billions $ damages of natural and manmade disasters and claiming much life (which we cannot account their worth by money, psychological and economical problems as aftermath of disasters, Creating NDMO in president’s office has many advantages. Disaster management is a cycle started from mitigation, preparedness, response and ended with recovery. In Iran, in mitigation and preparedness phases we have not done much. There is no stiff rule in building code, planning for response, drill and etc. We have had many disasters and we have many experiences in response, so DMS, response to disasters rationally well. Preparedness for response increase effectiveness and efficiency of

  17. The Impact Study of a Statcom on Commutation Failures in an HVDC Inverter Feeding a Weak AC System

    Science.gov (United States)

    Khatir, Mohamed; Zidi, Sid-Ahmed; Fellah, Mohammed-Karim; Hadjeri, Samir; Flitti, Mohamed

    2012-03-01

    The Static Synchronous Compensator (STATCOM) devices are pure power electronics devices that use voltage source, IGBT, IGCT or GTO based converters to generate reactive current. This paper illustrates the effect of STATCOM connected whit an HVDC inverter feeding a weak AC network, on the recovery from commutation failures following AC side disturbances. MATLAB/SIMULINK simulation results have demonstrated the robust performance of the proposed system based on the first CIGRÉ HVDC Benchmark model against commutation failures.

  18. Asymptotic Behavior of Global Classical Solutions of Quasilinear Non-strictly Hyperbolic Systems with Weakly Linear Degeneracy

    Institute of Scientific and Technical Information of China (English)

    Wenrong DAI

    2006-01-01

    In this paper, we study the asymptotic behavior of global classical solutions of the Cauchy problem for general quasilinear hyperbolic systems with constant multiple and weakly linearly degenerate characteristic fields. Based on the existence of global classical solution proved by Zhou Yi et al., we show that, when t tends to infinity, the solution approaches a combination of C1 travelling wave solutions, provided that the total variation and the L1 norm of initial data are sufficiently small.

  19. Simple statistical channel model for weak temperature-induced turbulence in underwater wireless optical communication systems

    KAUST Repository

    Oubei, Hassan M.

    2017-06-16

    In this Letter, we use laser beam intensity fluctuation measurements to model and describe the statistical properties of weak temperature-induced turbulence in underwater wireless optical communication (UWOC) channels. UWOC channels with temperature gradients are modeled by the generalized gamma distribution (GGD) with an excellent goodness of fit to the measured data under all channel conditions. Meanwhile, thermally uniform channels are perfectly described by the simple gamma distribution which is a special case of GGD. To the best of our knowledge, this is the first model that comprehensively describes both thermally uniform and gradient-based UWOC channels.

  20. The ρ(ω/B*(B system and bound states in the unitary local Hidden Gauge approach

    Directory of Open Access Journals (Sweden)

    Fernandez-Soler P.

    2016-01-01

    Full Text Available In this work, we study systems composed of a ρ/ω and B* meson pair. We find three bound states in isospin, spin-parity channels (1/2, 0+, (1/2, 1+ and (1/2, 2+. The state with J = 2 can be a good candidate for the B*2(5747. We also study the ρB system, and a bound state with mass 5728 MeV and width around 20 MeV is obtained, which can be identified with the B1(5721 resonance. In the case of I = 3/2, one obtains repulsion and thus, no exotic (molecular mesons in this sector are generated in the approach.

  1. Energy of the low-lying bound S-states of exotic two-muon three-body systems

    CERN Document Server

    Khan, Md Abdul

    2014-01-01

    Energies of the low-lying bound S-states (L=0) of exotic three-body systems, consisting a nuclear core of charge +Ze (Z being atomic number of the core) and two negatively charged valence muons, have been calculated by hyperspherical harmonics expansion method (HHEM). The three-body Schr\\H{o}dinger equation is solved assuming purely Coulomb interaction among the binary pairs of the three-body systems X$^{Z+}\\mu^-\\mu^-$ for Z=1 to 54. Convergence pattern of the energies have been checked with respect to the increasing number of partial waves $K_{max}$. For available computer facilities, calculations are feasible up to $K_{max}=28$ partial waves, however, calculation for still higher partial waves have been achieved through an appropriate extrapolation scheme. The dependence of bound state energies has been checked against increasing nuclear charge Z and finally, the calculated energies have been compared with the ones of the literature.

  2. Adaptive dynamic programming for finite-horizon optimal control of discrete-time nonlinear systems with ε-error bound.

    Science.gov (United States)

    Wang, Fei-Yue; Jin, Ning; Liu, Derong; Wei, Qinglai

    2011-01-01

    In this paper, we study the finite-horizon optimal control problem for discrete-time nonlinear systems using the adaptive dynamic programming (ADP) approach. The idea is to use an iterative ADP algorithm to obtain the optimal control law which makes the performance index function close to the greatest lower bound of all performance indices within an ε-error bound. The optimal number of control steps can also be obtained by the proposed ADP algorithms. A convergence analysis of the proposed ADP algorithms in terms of performance index function and control policy is made. In order to facilitate the implementation of the iterative ADP algorithms, neural networks are used for approximating the performance index function, computing the optimal control policy, and modeling the nonlinear system. Finally, two simulation examples are employed to illustrate the applicability of the proposed method.

  3. Search for weakly decaying Λn‾ and ΛΛ exotic bound states in central Pb–Pb collisions at sNN=2.76 TeV

    Directory of Open Access Journals (Sweden)

    J. Adam

    2016-01-01

    Full Text Available We present results of a search for two hypothetical strange dibaryon states, i.e. the H-dibaryon and the possible Λn‾ bound state. The search is performed with the ALICE detector in central (0–10% Pb–Pb collisions at sNN=2.76 TeV, by invariant mass analysis in the decay modes Λn‾→d‾π+ and H-dibaryon →Λpπ−. No evidence for these bound states is observed. Upper limits are determined at 99% confidence level for a wide range of lifetimes and for the full range of branching ratios. The results are compared to thermal, coalescence and hybrid UrQMD model expectations, which describe correctly the production of other loosely bound states, like the deuteron and the hypertriton.

  4. Search for weakly decaying $\\overline{\\Lambda\\mathrm{n}}$ and $\\Lambda\\Lambda $ exotic bound states in central Pb-Pb collisions at $\\sqrt{s_{\\rm NN}}$ = 2.76 TeV

    CERN Document Server

    Adam, Jaroslav; Aggarwal, Madan Mohan; Aglieri Rinella, Gianluca; Agnello, Michelangelo; Agrawal, Neelima; Ahammed, Zubayer; Ahmed, Ijaz; Ahn, Sang Un; Aimo, Ilaria; Aiola, Salvatore; Ajaz, Muhammad; Akindinov, Alexander; Alam, Sk Noor; Aleksandrov, Dmitry; Alessandro, Bruno; Alexandre, Didier; Alfaro Molina, Jose Ruben; Alici, Andrea; Alkin, Anton; Alme, Johan; Alt, Torsten; Altinpinar, Sedat; Altsybeev, Igor; Alves Garcia Prado, Caio; Andrei, Cristian; Andronic, Anton; Anguelov, Venelin; Anielski, Jonas; Anticic, Tome; Antinori, Federico; Antonioli, Pietro; Aphecetche, Laurent Bernard; Appelshaeuser, Harald; Arcelli, Silvia; Armesto Perez, Nestor; Arnaldi, Roberta; Aronsson, Tomas; Arsene, Ionut Cristian; Arslandok, Mesut; Augustinus, Andre; Averbeck, Ralf Peter; Azmi, Mohd Danish; Bach, Matthias Jakob; Badala, Angela; Baek, Yong Wook; Bagnasco, Stefano; Bailhache, Raphaelle Marie; Bala, Renu; Baldisseri, Alberto; Ball, Markus; Baltasar Dos Santos Pedrosa, Fernando; Baral, Rama Chandra; Barbano, Anastasia Maria; Barbera, Roberto; Barile, Francesco; Barnafoldi, Gergely Gabor; Barnby, Lee Stuart; Ramillien Barret, Valerie; Bartalini, Paolo; Bartke, Jerzy Gustaw; Bartsch, Esther; Basile, Maurizio; Bastid, Nicole; Basu, Sumit; Bathen, Bastian; Batigne, Guillaume; Batista Camejo, Arianna; Batyunya, Boris; Batzing, Paul Christoph; Bearden, Ian Gardner; Beck, Hans; Bedda, Cristina; Behera, Nirbhay Kumar; Belikov, Iouri; Bellini, Francesca; Bello Martinez, Hector; Bellwied, Rene; Belmont Iii, Ronald John; Belmont Moreno, Ernesto; Belyaev, Vladimir; Bencedi, Gyula; Beole, Stefania; Berceanu, Ionela; Bercuci, Alexandru; Berdnikov, Yaroslav; Berenyi, Daniel; Bertens, Redmer Alexander; Berzano, Dario; Betev, Latchezar; Bhasin, Anju; Bhat, Inayat Rasool; Bhati, Ashok Kumar; Bhattacharjee, Buddhadeb; Bhom, Jihyun; Bianchi, Livio; Bianchi, Nicola; Bianchin, Chiara; Bielcik, Jaroslav; Bielcikova, Jana; Bilandzic, Ante; Biswas, Saikat; Bjelogrlic, Sandro; Blanco, Fernando; Blau, Dmitry; Blume, Christoph; Bock, Friederike; Bogdanov, Alexey; Boggild, Hans; Boldizsar, Laszlo; Bombara, Marek; Book, Julian Heinz; Borel, Herve; Borissov, Alexander; Borri, Marcello; Bossu, Francesco; Botje, Michiel; Botta, Elena; Boettger, Stefan; Braun-Munzinger, Peter; Bregant, Marco; Breitner, Timo Gunther; Broker, Theo Alexander; Browning, Tyler Allen; Broz, Michal; Brucken, Erik Jens; Bruna, Elena; Bruno, Giuseppe Eugenio; Budnikov, Dmitry; Buesching, Henner; Bufalino, Stefania; Buncic, Predrag; Busch, Oliver; Buthelezi, Edith Zinhle; Buxton, Jesse Thomas; Caffarri, Davide; Cai, Xu; Caines, Helen Louise; Calero Diaz, Liliet; Caliva, Alberto; Calvo Villar, Ernesto; Camerini, Paolo; Carena, Francesco; Carena, Wisla; Castillo Castellanos, Javier Ernesto; Castro, Andrew John; Casula, Ester Anna Rita; Cavicchioli, Costanza; Ceballos Sanchez, Cesar; Cepila, Jan; Cerello, Piergiorgio; Chang, Beomsu; Chapeland, Sylvain; Chartier, Marielle; Charvet, Jean-Luc Fernand; Chattopadhyay, Subhasis; Chattopadhyay, Sukalyan; Chelnokov, Volodymyr; Cherney, Michael Gerard; Cheshkov, Cvetan Valeriev; Cheynis, Brigitte; Chibante Barroso, Vasco Miguel; Dobrigkeit Chinellato, David; Chochula, Peter; Choi, Kyungeon; Chojnacki, Marek; Choudhury, Subikash; Christakoglou, Panagiotis; Christensen, Christian Holm; Christiansen, Peter; Chujo, Tatsuya; Chung, Suh-Urk; Cicalo, Corrado; Cifarelli, Luisa; Cindolo, Federico; Cleymans, Jean Willy Andre; Colamaria, Fabio Filippo; Colella, Domenico; Collu, Alberto; Colocci, Manuel; Conesa Balbastre, Gustavo; Conesa Del Valle, Zaida; Connors, Megan Elizabeth; Contreras Nuno, Jesus Guillermo; Cormier, Thomas Michael; Corrales Morales, Yasser; Cortes Maldonado, Ismael; Cortese, Pietro; Cosentino, Mauro Rogerio; Costa, Filippo; Crochet, Philippe; Cruz Albino, Rigoberto; Cuautle Flores, Eleazar; Cunqueiro Mendez, Leticia; Dahms, Torsten; Dainese, Andrea; Danu, Andrea; Das, Debasish; Das, Indranil; Das, Supriya; Dash, Ajay Kumar; Dash, Sadhana; De, Sudipan; De Caro, Annalisa; De Cataldo, Giacinto; 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Zyzak, Maksym

    2016-01-10

    We present results of a search for two hypothetical strange dibaryon states, i.e. the H-dibaryon and the possible $\\overline{\\Lambda\\mathrm{n}}$ bound state. The search is performed with the ALICE detector in central (0-10%) Pb-Pb collisions at $ \\sqrt{s_{\\rm{NN}}} = 2.76$ TeV, by invariant mass analysis in the decay modes $\\overline{\\Lambda\\mathrm{n}} \\rightarrow \\overline{\\mathrm{d}} \\pi^{+} $ and H-dibaryon $\\rightarrow \\Lambda \\mathrm{p} \\pi^{-}$. No evidence for these bound states is observed. Upper limits are determined at 99% confidence level for a wide range of lifetimes and for the full range of branching ratios. The results are compared to thermal, coalescence and hybrid UrQMD model expectations, which describe correctly the production of other loosely bound states, like the deuteron and the hypertriton.

  5. A bounded confidence approach to understanding user participation in peer production systems

    CERN Document Server

    Ciampaglia, Giovanni Luca

    2011-01-01

    Commons-based peer production does seem to rest upon a paradox. Although users produce all contents, at the same time participation is commonly on a voluntary basis, and largely incentivized by achievement of project's goals. This means that users have to coordinate their actions and goals, in order to keep themselves from leaving. While this situation is easily explainable for small groups of highly committed, like-minded individuals, little is known about large-scale, heterogeneous projects, such as Wikipedia. In this contribution we present a model of peer production in a large online community. The model features a dynamic population of bounded confidence users, and an endogenous process of user departure. Using global sensitivity analysis, we identify the most important parameters affecting the lifespan of user participation. We find that the model presents two distinct regimes, and that the shift between them is governed by the bounded confidence parameter. For low values of this parameter, users depart...

  6. Differential Privacy for Relational Algebra: Improving the Sensitivity Bounds via Constraint Systems

    Directory of Open Access Journals (Sweden)

    Catuscia Palamidessi

    2012-07-01

    Full Text Available Differential privacy is a modern approach in privacy-preserving data analysis to control the amount of information that can be inferred about an individual by querying a database. The most common techniques are based on the introduction of probabilistic noise, often defined as a Laplacian parametric on the sensitivity of the query. In order to maximize the utility of the query, it is crucial to estimate the sensitivity as precisely as possible. In this paper we consider relational algebra, the classical language for queries in relational databases, and we propose a method for computing a bound on the sensitivity of queries in an intuitive and compositional way. We use constraint-based techniques to accumulate the information on the possible values for attributes provided by the various components of the query, thus making it possible to compute tight bounds on the sensitivity.

  7. [Reduction of nitrobenzene by iron oxides bound Fe(II) system at different pH values].

    Science.gov (United States)

    Luan, Fu-Bo; Xie, Li; Li, Jun; Zhou, Qi

    2009-07-15

    Batch tests were conducted to investigate the reductive transformation of nitrobenzene by goethite, hematite, magnetite and steel converter slag bound Fe(II) system. And the reduction mechanism was explored at different pH values. Experimental results showed that hematite, magnetite and steel converter slag could adsorb Fe(II) on surfaces and form iron oxides bound Fe(II) system at pH from 6.5 to 7.0. The systems had strong reductive capacity and could reduce nitrobenzene to aniline. The reduction efficiency of nitrobenzene in surface bound Fe(II) system followed the sequence of magnetite, hematite and steel converter slag from high to low. The reduction efficiency of hematite and magnetite system increased with pH increasing. While it was almost pH independent in steel converter slag system. Although goethite adsorbed most of Fe(II) in solution, the adsorbed Fe(II) had no reductive activity for nitrobenzene. At pH 6.0, small amount of Fe(II) was adsorbed on magnetite and hematite and the systems did not show reductive activity for nitrobenzene. However, steel converter slag could adsorb Fe(II) at pH 6.0 and reduction efficiency almost equaled to the value at pH 7.0. When pH was above 7.5, dissolved Fe(II) could be converted to Fe(OH)2 and the newly formed Fe(OH)2 became the main redactor in the system. Under alkali condition, the presence of iron oxides inhibited the reduction capacity of system.

  8. Search for weakly decaying $\\bar{\\Lambda\\mathrm{n}}$ and $\\Lambda\\Lambda $ exotic bound states in central Pb-Pb collisions at $\\sqrt{s_{\\rm NN}}$ = 2.76 TeV

    OpenAIRE

    Adam, Jaroslav; Adamova, Dagmar; Aiola, Salvatore; Bilandzic, Ante; Biswas, Saikat; Bjelogrlic, Sandro; Blanco, Fernando; Blau, Dmitry; Blume, Christoph; Bock, Friederike; Bogdanov, Alexey; Boggild, Hans; Boldizsar, Laszlo; Ajaz, Muhammad; Bombara, Marek

    2016-01-01

    We present results of a search for two hypothetical strange dibaryon states, i.e. the H-dibaryon and the possible Λn‾ bound state. The search is performed with the ALICE detector in central (0–10%) Pb–Pb collisions at sNN=2.76 TeV , by invariant mass analysis in the decay modes Λn‾→d‾π+ and H-dibaryon →Λpπ− . No evidence for these bound states is observed. Upper limits are determined at 99% confidence level for a wide range of lifetimes and for the full range of branching ratios. The results ...

  9. Design of robust iterative learning control schemes for systems with polytopic uncertainties and sector-bounded nonlinearities

    Science.gov (United States)

    Boski, Marcin; Paszke, Wojciech

    2017-01-01

    This paper deals with designing of iterative learning control schemes for uncertain systems with static nonlinearities. More specifically, the nonlinear part is supposed to be sector bounded and system matrices are assumed to range in the polytope of matrices. For systems with such nonlinearities and uncertainties the repetitive process setting is exploited to develop a linear matrix inequality based conditions for computing the feedback and feedforward (learning) controllers. These controllers guarantee acceptable dynamics along the trials and ensure convergence of the trial-to-trial error dynamics, respectively. Numerical examples illustrate the theoretical results and confirm effectiveness of the designed control scheme.

  10. Optical properties of an inhomogeneously broadened multilevel V-system in the weak and strong probe regimes

    CERN Document Server

    Kaur, Paramjit; Wasan, Ajay

    2015-01-01

    We present a theoretical model, using density matrix approach, to study the effect of weak as well as strong probe field on the optical properties of an inhomogeneously broadened multilevel V-system of the $^{87}$Rb D2 line. We consider the case of stationary as well as moving atoms and perform thermal averaging at room temperature. The presence of multiple excited states results in asymmetric absorption and dispersion profiles. In the weak probe regime, we observe the partial transparency window due to the constructive interference occurs between transition pathways at the line center. In a room temperature vapour, we obtain an increased linewidth of the transparency window and steep positive dispersion. For a strong probe regime, the transparency window with normal dispersion switches to enhanced absorption with anomalous dispersion at the line center. Here, we show how the electromagnetically induced transparency (EIT) depends on the polarizations of the applied fields. We also discuss the transient behavi...

  11. Optimization-Based Drift Prevention for Learning Control of Underdetermined Linear and Weakly Nonlinear Time-Varying Systems

    Energy Technology Data Exchange (ETDEWEB)

    DRIESSEN,BRIAN JAMES; SADEGH,NADER; KWOK,KWAN S.

    2000-10-20

    In this paper an optimization-based method of drift prevention is presented for learning control of underdetermined linear and weakly nonlinear time-varying dynamic systems. By defining a fictitious cost function and the associated model-based sub-optimality conditions, a new set of equations results, whose solution is unique, thus preventing large drifts from the initial input. Moreover, in the limiting case where the modeling error approaches zero, the input that the proposed method converges to is the unique feasible (zero error) input that minimizes the fictitious cost function, in the linear case, and locally minimizes it in the (weakly) nonlinear case. Otherwise, under mild restrictions on the modeling error, the method converges to a feasible sub-optimal input.

  12. Electron-Lattice Systems in Weak Gravitation: The Schiff Dessler Problem

    CERN Document Server

    Datta, Timir; Yin, Ming

    2009-01-01

    The behavior of composite matter in external fields can be very reveling. The quantum mechanical problem of a material object (test mass) placed in a uniform (weak) gravitational field, g, was considered by many authors starting with Schiff [Phys. Rev. 151, 1067 (1966)]. Depending on the theoretical treatment opposing results of gravity induced (electric) field have been reported. In the Schiff model [L.I. Schiff, PRB, 1, 4649 (1970)] the field is predicted to be oriented anti-parallel (with reference to g). On the other hand it is found to be parallel in the elastic lattice model [A. J. Dessler et al, Phys.Rev, 168, 737, (1968); Edward Teller, PNAS, 74, 2664 (1977)]. Surprisingly, modern researchers have largely overlooked this interesting contradiction. Here an experimental test is suggested. We also reason that advanced density functional type calculations can provide valuable guidance.

  13. Non-Hermitian wave packet approximation for coupled two-level systems in weak and intense fields

    CERN Document Server

    Puthumpally-joseph, Raiju; Charron, Eric

    2016-01-01

    We introduce an accurate non-Hermitian Schr\\"odinger-type approximation of Bloch optical equations for two-level systems. This approximation provides a complete description of the excitation, relaxation and decoherence dynamics in both weak and strong laser fields. In this approach, it is sufficient to propagate the wave function of the quantum system instead of the density matrix, providing that relaxation and dephasing are taken into account via automatically-adjusted time-dependent gain and decay rates. The developed formalism is applied to the problem of scattering and absorption of electromagnetic radiation by a thin layer comprised of interacting two-level emitters.

  14. Bounding species distribution models

    Directory of Open Access Journals (Sweden)

    Thomas J. STOHLGREN, Catherine S. JARNEVICH, Wayne E. ESAIAS,Jeffrey T. MORISETTE

    2011-10-01

    Full Text Available Species distribution models are increasing in popularity for mapping suitable habitat for species of management concern. Many investigators now recognize that extrapolations of these models with geographic information systems (GIS might be sensitive to the environmental bounds of the data used in their development, yet there is no recommended best practice for “clamping” model extrapolations. We relied on two commonly used modeling approaches: classification and regression tree (CART and maximum entropy (Maxent models, and we tested a simple alteration of the model extrapolations, bounding extrapolations to the maximum and minimum values of primary environmental predictors, to provide a more realistic map of suitable habitat of hybridized Africanized honey bees in the southwestern United States. Findings suggest that multiple models of bounding, and the most conservative bounding of species distribution models, like those presented here, should probably replace the unbounded or loosely bounded techniques currently used [Current Zoology 57 (5: 642–647, 2011].

  15. Bounding Species Distribution Models

    Science.gov (United States)

    Stohlgren, Thomas J.; Jarnevich, Cahterine S.; Morisette, Jeffrey T.; Esaias, Wayne E.

    2011-01-01

    Species distribution models are increasing in popularity for mapping suitable habitat for species of management concern. Many investigators now recognize that extrapolations of these models with geographic information systems (GIS) might be sensitive to the environmental bounds of the data used in their development, yet there is no recommended best practice for "clamping" model extrapolations. We relied on two commonly used modeling approaches: classification and regression tree (CART) and maximum entropy (Maxent) models, and we tested a simple alteration of the model extrapolations, bounding extrapolations to the maximum and minimum values of primary environmental predictors, to provide a more realistic map of suitable habitat of hybridized Africanized honey bees in the southwestern United States. Findings suggest that multiple models of bounding, and the most conservative bounding of species distribution models, like those presented here, should probably replace the unbounded or loosely bounded techniques currently used [Current Zoology 57 (5): 642-647, 2011].

  16. Existence of positive radial solutions for a weakly coupled system via blow up

    Directory of Open Access Journals (Sweden)

    Marta García-Huidobro

    1998-01-01

    Full Text Available The existence of positive solutions to certain systems of ordinary differential equations is studied. Particular forms of these systems are satisfied by radial solutions of associated partial differential equations.

  17. Design Research in Cyber-Physical Systems through Weak-Bisimulation

    Directory of Open Access Journals (Sweden)

    Roy Mccann

    2011-12-01

    Full Text Available Bisimulation methods for design and verification of complex digital electronics have become well established in engineering practice. Concurrently, there have been dramatic theoretical advances in the theory of hybrid dynamical systems. This paper explores the how these advances can be incorporated into research methods for the emerging area of cyber-physical systems from a cybernetics perspective. The results can be used in determining how design of engineered systems can be safely integrated into physical systems.

  18. Queue Content Analysis in a 2-Class Discrete-Time Queueing System under the Slot-Bound Priority Service Rule

    Directory of Open Access Journals (Sweden)

    Sofian De Clercq

    2012-01-01

    Full Text Available The paper we present here introduces a new priority mechanism in discrete-time queueing systems. It is a milder form of priority when compared to HoL priority, but it favors customers of one type over the other when compared to regular FCFS. It also provides an answer to the starvation problem that occurs in HoL priority systems. In this new priority mechanism, customers of different priority classes entering the system during the same time slot are served in order of their respective priority class—hence the name slot-bound priority. Customers entering during different slots are served on an FCFS basis. We consider two customer classes (pertaining to two levels of priority such that type-1 customers are served before type-2 customers that enter the system during the same slot. A general independent arrival process and generally distributed service times are assumed. Expressions for the probability generating function (PGF of the system content (number of type- customers, in regime are obtained using a slot-to-slot analysis. The first moments are calculated, as well as an approximation for the probability mass functions associated with the found PGFs. Lastly, some examples allow us some deeper insight into the inner workings of the slot-bound priority mechanism.

  19. On the uniqueness and existence of entropy solutions of weakly coupled systems of nonlinear degenerate parabolic equations

    Energy Technology Data Exchange (ETDEWEB)

    Holden, Helge; Karlsen, Kenneth H.; Risebro, Nils H.

    2002-04-01

    We prove uniqueness and existence of entropy solutions for the Cauchy problem of weakly coupled systems of nonlinear degenerate parabolic equations. The uniqueness proof is an adaption of Kruzkov's ''doubling of variables'' proof. We prove existence of an entropy solution by demonstrating that the Engquist-Osher finite difference scheme is convergent and that any limit function satisfies the entropy condition. The convergence proof is based on deriving a series of a priori estimates and using a general L{sup p} compactness criterion. We also present a numerical example motivated by biodegradation in porous media.

  20. Berry{close_quote}s phase and a possible new topological current drive in certain weak link superconducting systems

    Energy Technology Data Exchange (ETDEWEB)

    Gaitan, F.; Shenoy, S.R. [International Center for Theoretical Physics, P. O. Box 586, Miramare, 34100 Trieste (Italy)

    1996-06-01

    We examine the consequences of Berry{close_quote}s phase for the dynamics of Josephson junctions and junction arrays in which moving vortices are present. For both a large annular Josephson junction and a 2D junction array, Berry{close_quote}s phase produces a new current drive in the superconducting phase dynamics of these weak link systems. This Berry phase effect is shown to be physically inequivalent to a known effect in junction arrays associated with the Aharonov-Casher phase. {copyright} {ital 1996 The American Physical Society.}

  1. Grading systems in head and neck dysplasia: their prognostic value, weaknesses and utility.

    Science.gov (United States)

    Fleskens, Stijn; Slootweg, Piet

    2009-05-11

    Grading of dysplasia, including head and neck lesions, continues to be a hotly debated subject. It is subjective and lacks intra- and inter-observer reproducibility due to the insufficiency of validated morphological criteria and the biological nature of dysplasia. Moreover, due to the absence of a consensus, several systems are currently employed. The aims of this review are to: 1) Highlight the significance of dysplasia and the importance of a valid method for assessing precursor lesions of the head and neck. 2) Review the different histopathological classification systems for grading intraepithelial lesions of the head and neck. 3) Discuss and review quality requirements for these grading systems. Regarding the different classification systems, data concerning the WHO classification system are the most available in current literature. There is no simple relationship or overlapping between the classification systems. Further studies should be done to see whether other systems have advantages above the current WHO system and to discover indications that could lead to an universal classification system for intraepithelial lesions of the head and neck.

  2. Existence and Uniform Decay of Weak Solutions for Nonlinear Thermoelastic System with Memory

    Directory of Open Access Journals (Sweden)

    Liu Haihong

    2009-01-01

    Full Text Available A nonlinear thermoelastic system with memory is considered, which is derived from a physical model with vibration in temperature environment. By some skillful and technical arguments, results of existence, uniqueness, and uniform decay on this generalized system are obtained.

  3. Weak Centers and Local Bifurcations of Critical Periods at Infinity for a Class of Rational Systems

    Institute of Scientific and Technical Information of China (English)

    Wen-tao HUANG; Valery G. ROMANOVSKI; WEI-NIAN ZHANG

    2013-01-01

    We describe an approach to studying the center problem and local bifurcations of critical periods at infinity for a class of differential systems.We then solve the problem and investigate the bifurcations for a class of rational differential systems with a cubic polynomial as its numerator.

  4. Error bounds for set inclusions

    Institute of Scientific and Technical Information of China (English)

    ZHENG; Xiyin(郑喜印)

    2003-01-01

    A variant of Robinson-Ursescu Theorem is given in normed spaces. Several error bound theorems for convex inclusions are proved and in particular a positive answer to Li and Singer's conjecture is given under weaker assumption than the assumption required in their conjecture. Perturbation error bounds are also studied. As applications, we study error bounds for convex inequality systems.

  5. Integration of large wind farms into weak power grids. Emphasis on the Ethiopian interconnected system (ICS)

    Energy Technology Data Exchange (ETDEWEB)

    Bantyirga Gessesse, Belachew

    2013-07-18

    The impact of increased wind power on the steady state and dynamic behavior of the Ethiopian power system is the main focus of this thesis. The integration of wind power to the existing grid with conventional generators introduces new set of challenges regarding system security and operational planning, the main cause of the difference arising from the uncertainty of the primary source of energy and the response time following a disturbance. For incorporating wind turbine models into the overall dynamic model of the system and investigating the effect of wind on the dynamic behavior of the wind first models of wind turbine components were put together by reviewing the current state of the art in wind turbine modeling and control concepts. The theoretical insight thus gained was applied to the Ethiopian power system as a case study. Since the models of the installed turbines were either not available or incomplete, an alternative modeling approach based on generic models was adopted. The generic model, in addition to obviating the need for technology or manufacturer specific models, reduces the complexity the dynamic model. Using this procedure, generic dynamic models for wind farm in the system were developed. The capability of dynamic models to reproduce the dynamic response of the system has been verified by comparing simulation results obtained with a detailed and generic wind farm model. It could be shown that the generic wind turbine model is simple, but accurate enough to represent any wind turbine types or entire wind farms for power system stability analysis. The next task was the study of the effect of increased wind power level on the general behavior of the Ethiopian system. It is observed that overall the impact of wind turbines on the operational indices of the system was -as could be expected- more pronounced in the vicinity of the wind farm. But the power angle oscillation following a disturbance was observed across the whole system. Further, as a

  6. Crossing the Boundaries of Our Current Healthcare System by Integrating Ultra-Weak Photon Emissions with Metabolomics

    Science.gov (United States)

    Burgos, Rosilene C. Rossetto; van Wijk, Eduard P. A.; van Wijk, Roeland; He, Min; van der Greef, Jan

    2016-01-01

    The current healthcare system is hampered by a reductionist approach in which diagnostics and interventions focus on a specific target, resulting in medicines that center on generic, static phenomena while excluding inherent dynamic nature of biological processes, let alone psychosocial parameters. In this essay, we present some limitations of the current healthcare system and introduce the novel and potential approach of combining ultra-weak photon emission (UPE) with metabolomics technology in order to provide a dynamic readout of higher organizational systems. We argue that the combination of metabolomics and UPE can bring a new, broader, view of health state and can potentially help to shift healthcare toward more personalized approach that improves patient well-being. PMID:28018239

  7. Crossing the boundaries of our current healthcare system by integrating ultra-weak photon emissions with metabolomics

    Directory of Open Access Journals (Sweden)

    Rosilene Cristina Rossetto Burgos

    2016-12-01

    Full Text Available The current healthcare system is hampered by a reductionist approach in which diagnostics and interventions focus on a specific target, resulting in medicines that center on generic, static phenomena while excluding inherent dynamic nature of biological processes, let alone psychosocial parameters. In this essay, we present some limitations of the current healthcare system and introduce the novel and potential approach of combining ultra-weak photon emission (UPE with metabolomics technology in order to provide a dynamic readout of higher organizational systems. We argue that the combination of metabolomics and UPE can bring a new, broader, view of health state and can potentially help to shift healthcare towards more personalized approach that improves patient well-being.

  8. Variations of Positive and Negative Dispersions in Both Highly and Weakly Absorptive Atomic Systems

    Science.gov (United States)

    Abi-Salloum, Tony; Snell, Scott; Davis, Jon; Narducci, Frank

    2011-05-01

    Positive and negative dispersive media are essential in subluminal, superluminal and negative group velocity pulse propagation applications. Three-level atomic media at resonance, especially the Lambda configuration, are positively dispersive and transparent. In contrast, two-level atomic systems are negatively dispersive and opaque. In this work we study higher level atomic systems comprised of three fields coupled to three levels (double lambda) or four levels (N-Scheme). We explore the systems of interest for critical features such as negative dispersion and transparency, a combination that is needed in numerous applications, e.g. optical gyroscopes. We solve the time dependent equations perturbatively and compare them to well established behavior in three-level systems. Some of the results are analyzed in terms of resonances which control the different features of the observed dispersive and absorptive behaviors.

  9. Resolution of a shock in hyperbolic systems modified by weak dispersion

    Science.gov (United States)

    El, G. A.

    2005-09-01

    We present a way to deal with dispersion-dominated "shock-type" transition in the absence of completely integrable structure for the systems that one may characterize as strictly hyperbolic regularized by a small amount of dispersion. The analysis is performed by assuming that the dispersive shock transition between two different constant states can be modeled by an expansion fan solution of the associated modulation (Whitham) system for the short-wavelength nonlinear oscillations in the transition region (the so-called Gurevich-Pitaevskii problem). We consider both single-wave and bidirectional systems. The main mathematical assumption is that of hyperbolicity of the Whitham system for the solutions of our interest. By using general properties of the Whitham averaging for a certain class of nonlinear dispersive systems and specific features of the Cauchy data prescription on characteristics we derive a set of transition conditions for the dispersive shock, actually bypassing full integration of the modulation equations. Along with the Korteweg-de Vries (KdV) and modified KdV (mKdV) equations as model examples, we consider a nonintegrable system describing fully nonlinear ion-acoustic waves in collisionless plasma. In all cases our transition conditions are in complete agreement with previous analytical and numerical results.

  10. A systems perspective of waste and energy - Strengths and weaknesses of the ORWARE model

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, Ola

    2000-11-01

    Waste management of today in Sweden is a complex phenomenon that demands for a scientific and systematic approach. The complexity is a result of a wide variety of actors, technologies, and impact on the environment, health, and the economy. Waste management also has a high relevance with respect to energy. There are direct connections as e.g. energy recovery from waste, but also indirect as the systems complexity and the environmental and economical impacts. Helpful tools in the planning of waste management are different types of models of which ORWARE is one. Based on principles from Life Cycle Analysis (LCA) and complemented with a simple Cost Benefit Analysis (CBA) ORWARE can provide some help in finding environmentally sound solutions for waste management systems. The model does not answer all questions raised by practitioners but can still be used for advisory purposes. The model does not include sociological or political aspects but it covers the area of physical flows with impacts on environment, society and economy. Other impacts have to be considered with other methods. The experiences from using ORWARE in Swedish municipalities during more than a half decade clearly shows the advantages and disadvantages of the tool. The model is very flexible when it comes to the possibility of site-specific adjustments of input data and process functions. With help of the model the complexity of the studied system can be illustrated by e.g. a map of the number of connections between different types of information. In this way ORWARE supports dialogue between different stakeholders and collects knowledge in a unique way. On the other hand, modelling such an extensive and complex system often leads to errors that takes time to find and correct. The model can not be considered as user friendly and does not cover all aspects wanted by the society. There are also educational problems with different time frames and space boundaries in the analysis that make the results hard

  11. An efficient and accurate approximation to time-dependent density functional theory for systems of weakly coupled monomers

    Science.gov (United States)

    Liu, Jie; Herbert, John M.

    2015-07-01

    A novel formulation of time-dependent density functional theory (TDDFT) is derived, based on non-orthogonal, absolutely-localized molecular orbitals (ALMOs). We call this approach TDDFT(MI), in reference to ALMO-based methods for describing molecular interactions (MI) that have been developed for ground-state applications. TDDFT(MI) is intended for efficient excited-state calculations in systems composed of multiple, weakly interacting chromophores. The efficiency is based upon (1) a local excitation approximation; (2) monomer-based, singly-excited basis states; (3) an efficient localization procedure; and (4) a one-step Davidson method to solve the TDDFT(MI) working equation. We apply this methodology to study molecular dimers, water clusters, solvated chromophores, and aggregates of naphthalene diimide that form the building blocks of self-assembling organic nanotubes. Absolute errors of 0.1-0.3 eV with respect to supersystem methods are achievable for these systems, especially for cases involving an excited chromophore that is weakly coupled to several explicit solvent molecules. Excited-state calculations in an aggregate of nine naphthalene diimide monomers are ˜40 times faster than traditional TDDFT calculations.

  12. Geometric field theory and weak Euler-Lagrange equation for classical relativistic particle-field systems

    CERN Document Server

    Fan, Peifeng; Liu, Jian; Xiang, Nong; Yu, Zhi

    2016-01-01

    A manifestly covariant, or geometric, field theory for relativistic classical particle-field system is developed. The connection between space-time symmetry and energy-momentum conservation laws for the system is established geometrically without splitting the space and time coordinates, i.e., space-time is treated as one identity without choosing a coordinate system. To achieve this goal, we need to overcome two difficulties. The first difficulty arises from the fact that particles and field reside on different manifold. As a result, the geometric Lagrangian density of the system is a function of the 4-potential of electromagnetic fields and also a functional of particles' world-lines. The other difficulty associated with the geometric setting is due to the mass-shell condition. The standard Euler-Lagrange (EL) equation for a particle is generalized into the geometric EL equation when the mass-shell condition is imposed. For the particle-field system, the geometric EL equation is further generalized into a w...

  13. Health system weaknesses constrain access to PMTCT and maternal HIV services in South Africa: a qualitative enquiry

    Directory of Open Access Journals (Sweden)

    Chersich Matthew F

    2011-03-01

    Full Text Available Abstract Background HIV remains responsible for an estimated 40% of mortality in South African pregnant women and their children. To address these avoidable deaths, eligibility criteria for antiretroviral therapy (ART in pregnant women were revised in 2010 to enhance ART coverage. With greater availability of HIV services in public health settings and increasing government attention to poor maternal-child health outcomes, this study used the patient's journey through the continuum of maternal and child care as a framework to track and document women's experiences of accessing ART and prevention of mother-to-child HIV transmission (PMTCT programmes in the Eastern Cape (three peri-urban facilities and Gauteng provinces (one academic hospital. Results In-depth interviews identified considerable weaknesses within operational HIV service delivery. These manifested as missed opportunities for HIV testing in antenatal care due to shortages of test kits; insufficient staff assigned to HIV services; late payment of lay counsellors, with consequent absenteeism; and delayed transcription of CD4 cell count results into patient files (required for ART initiation. By contrast, individual factors undermining access encompassed psychosocial concerns, such as fear of a positive test result or a partner's reaction; and stigma. Data and information systems for monitoring in the three peri-urban facilities were markedly inadequate. Conclusions A single system- or individual-level delay reduced the likelihood of women accessing ART or PMTCT interventions. These delays, when concurrent, often signalled wholesale denial of prevention and treatment. There is great scope for health systems' reforms to address constraints and weaknesses within PMTCT and ART services in South Africa. Recommendations from this study include: ensuring autonomy over resources at lower levels; linking performance management to facility-wide human resources interventions; developing

  14. Optimum quantum receiver for detecting weak signals in PAM communication systems

    Science.gov (United States)

    Sharma, Navneet; Rawat, Tarun Kumar; Parthasarathy, Harish; Gautam, Kumar

    2017-09-01

    This paper deals with the modeling of an optimum quantum receiver for pulse amplitude modulator (PAM) communication systems. The information bearing sequence {I_k}_{k=0}^{N-1} is estimated using the maximum likelihood (ML) method. The ML method is based on quantum mechanical measurements of an observable X in the Hilbert space of the quantum system at discrete times, when the Hamiltonian of the system is perturbed by an operator obtained by modulating a potential V with a PAM signal derived from the information bearing sequence {I_k}_{k=0}^{N-1}. The measurement process at each time instant causes collapse of the system state to an observable eigenstate. All probabilities of getting different outcomes from an observable are calculated using the perturbed evolution operator combined with the collapse postulate. For given probability densities, calculation of the mean square error evaluates the performance of the receiver. Finally, we present an example involving estimating an information bearing sequence that modulates a quantum electromagnetic field incident on a quantum harmonic oscillator.

  15. Can weak-resilience-signals (WRS) reveal obstacles compromising (rail-)system resilience?

    NARCIS (Netherlands)

    Siegel, A.W.; Schraagen, Johannes Martinus Cornelis

    2015-01-01

    Analysis of accidents in socio-technical systems frequently reveals unnoticed obstacles, which have grown to become the main cause of incubation and surprise at failure (Dekker, 2011). Thus far, it has proven to be a challenge to identify those unnoticed obstacles upfront among the tremendous number

  16. Internal Quality Assurance Systems in Portugal: What Their Strengths and Weaknesses Reveal

    Science.gov (United States)

    Tavares, Orlanda; Sin, Cristina; Amaral, Alberto

    2016-01-01

    In Portugal, the agency for assessment and accreditation of higher education has recently included in its remit, beyond programme accreditation, the certification of internal quality assurance systems. This implies lighter touch accreditation and aims to direct institutions towards improvement, in addition to accountability. Twelve institutions…

  17. The near optimality of the stabilizing control in a weakly nonlinear system with state-dependent coefficients

    Science.gov (United States)

    Dmitriev, Mikhail G.; Makarov, Dmitry A.

    2016-08-01

    We carried out analysis of near optimality of one computationally effective nonlinear stabilizing control built for weakly nonlinear systems with coefficients depending on the state and the formal small parameter. First investigation of that problem was made in [M. G. Dmitriev, and D. A. Makarov, "The suboptimality of stabilizing regulator in a quasi-linear system with state-depended coefficients," in 2016 International Siberian Conference on Control and Communications (SIBCON) Proceedings, National Research University, Moscow, 2016]. In this paper, another optimal control and gain matrix representations were used and theoretical results analogous to cited work above were obtained. Also as in the cited work above the form of quality criterion on which this close-loop control is optimal was constructed.

  18. Non-canonical distribution and non-equilibrium transport beyond weak system-bath coupling regime: A polaron transformation approach

    Science.gov (United States)

    Xu, Dazhi; Cao, Jianshu

    2016-08-01

    The concept of polaron, emerged from condense matter physics, describes the dynamical interaction of moving particle with its surrounding bosonic modes. This concept has been developed into a useful method to treat open quantum systems with a complete range of system-bath coupling strength. Especially, the polaron transformation approach shows its validity in the intermediate coupling regime, in which the Redfield equation or Fermi's golden rule will fail. In the polaron frame, the equilibrium distribution carried out by perturbative expansion presents a deviation from the canonical distribution, which is beyond the usual weak coupling assumption in thermodynamics. A polaron transformed Redfield equation (PTRE) not only reproduces the dissipative quantum dynamics but also provides an accurate and efficient way to calculate the non-equilibrium steady states. Applications of the PTRE approach to problems such as exciton diffusion, heat transport and light-harvesting energy transfer are presented.

  19. Chaos control on autonomous and non-autonomous systems with various types of genetic algorithm-optimized weak perturbations

    Energy Technology Data Exchange (ETDEWEB)

    Soong, C.Y. [Department of Aerospace and Systems Engineering, Feng Chia University, Seatwen, Taichung 40724, Taiwan (China)]. E-mail: cysoong@fcu.edu.tw; Huang, W.T. [Department of Marine Mechanical Engineering, Chinese Naval Academy, Kaohsiung 81300, Taiwan (China); Lin, F.P. [Grid Computing Division, National Center of High Performance Computing, Hsinchu 30012, Taiwan (China)

    2007-12-15

    Recently, we proposed a chaos control strategy with weak Fourier signals optimized by using a genetic algorithm (GA) and demonstrated its merits in controlling Lorenz and Roessler systems (Physical Review E, 2004). In this continuation work, performance of various types of signals, namely periodic continuous, periodic discrete, and constant bias (non-periodic), applied to an autonomous (Roessler) system and a non-autonomous (Murali-Lakshmanan-Chua, MLC) system are investigated. An index of relative robustness is proposed for measuring the noise-resisting ability of the control signals. The results reveal that the constant signal has the strongest noise-resisting ability, the periodic pulse signal has the weakest, and the Fourier signal falls in between. Phase modulation generally shortens the transient time period and is additionally beneficial to non-autonomous systems in minimizing significantly the signal power. By searching with the present GA-optimization, it is demonstrated that the minimum-power signal for controlling the non-autonomous (MLC) system is the signal with a frequency exactly the same as that of the system forcing but with phase modulation. The effectiveness of the GA-optimized signals of extremely low power employed in alternatively switching control of non-autonomous systems is also demonstrated.

  20. Space group constraints on weak indices in topological insulators

    Science.gov (United States)

    Varjas, Dániel; de Juan, Fernando; Lu, Yuan-Ming

    2017-07-01

    Lattice translation symmetry gives rise to a large class of "weak" topological insulators (TIs), characterized by translation-protected gapless surface states and dislocation bound states. In this work we show that space group symmetries lead to constraints on the weak topological indices that define these phases. In particular, we show that screw rotation symmetry enforces the Hall conductivity in planes perpendicular to the screw axis to be quantized in multiples of the screw rank, which generally applies to interacting systems. We further show that certain 3D weak indices associated with quantum spin Hall effects (class AII) are forbidden by the Bravais lattice and by glide or even-fold screw symmetries. These results put strong constraints on weak TI candidates in the experimental and numerical search for topological materials, based on the crystal structure alone.

  1. Exact calculations of a quasi-bound state in the $\\bar{K} \\bar{K} N$ system

    CERN Document Server

    Shevchenko, N V

    2015-01-01

    Dynamically exact calculations of a quasi-bound state in the $\\bar{K}\\bar{K}N$ three-body system are performed using Faddeev-type AGS equations. As input two phenomenological and one chirally motivated $\\bar{K}N$ potentials are used, which describe the experimental information on the $\\bar{K}N$ system equally well and produce either a one- or two-pole structure of the $\\Lambda(1405)$ resonance. For the $\\bar{K}\\bar{K}$ interaction separable potentials are employed that are fitted to phase shifts obtained from two theoretical models. The first one is a phenomenological $\\bar{K}\\bar{K}$ potential based on meson exchange, which is derived by SU(3) symmetry arguments from the J\\"ulich $\\pi \\pi - \\bar{K} K$ coupled-channels model. The other interaction is a variant of the first one, which is adjusted to the $KK$ s-wave scattering length recently determined in lattice QCD simulations. The position and width of the $\\bar{K}\\bar{K}N$ quasi-bound state is evaluated in two ways: (i) by a direct pole search in the compl...

  2. Cramér-Rao lower bound analysis for guidance systems with bearings-only measurements

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yong-an; ZHOU Di; DUAN Guang-ren

    2007-01-01

    Most currently existing investigations on the observability of passive guidance systems can only protimability analysis of closed-loop guidance systems with bearings-only measurements, is proposed. The new method provides an intuitive result for observability of the guidance system through graphical analysis. As a demonstration, a numerical example is presented, in which the degrees of observability of the guidance systems under two commonly used guidance laws are compared by using the new approach.

  3. Predicting Material Weaknesses In Internal Control Systems After The Sarbanes-Oxley Act Using Multiple Criteria Linear Programming And Other Data Mining Approaches

    National Research Council Canada - National Science Library

    Wikil Kwak; Susan Eldridge; Yong Shi; Gang Kou

    2009-01-01

      Our study proposes a multiple criteria linear programming (MCLP) and other data mining methods to predict material weaknesses in a firm's internal control system after the Sarbanes-Oxley Act (SOX) using 2003-2004 U.S. data...

  4. Strange Weak Values

    CERN Document Server

    Hosoya, Akio

    2010-01-01

    We develop a formal theory of the weak values with emphasis on the consistency conditions and a probabilistic interpretation in the counter-factual processes. We present the condition for the choice of the post-selected state to give a negative weak value of a given projection operator and strange values of an observable in general. The general framework is applied to Hardy's paradox and the spin $1/2$ system to explicitly address the issues of counter-factuality and strange weak values. The counter-factual arguments which characterize the paradox specifies the pre-selected state and a complete set of the post-selected states clarifies how the strange weak values emerge.

  5. Disclosing the multi-faceted world of weakly interacting inorganic systems by means of NMR spectroscopy.

    Science.gov (United States)

    Rocchigiani, Luca; Macchioni, Alceo

    2016-02-21

    The potential of NMR spectroscopy to investigate inorganic systems assembled by, or whose reactivity is affected by, non-covalent interactions is described. Subjects that have received particular attention in recent years (halogen bonding and Frustrated Lewis Pairs) and more classical subjects that remain under-explored (self-aggregation of ion pairs in low polar solvents, behavior of MAO containing metallocenium ion pairs, and hydrogen bonding/ion pairing effects in Au(i) catalysis) are considered, using an innovative approach, always focusing on the crucial information that can be provided by NMR.

  6. Generation-based memory synchronization in a multiprocessor system with weakly consistent memory accesses

    Science.gov (United States)

    Ohmacht, Martin

    2014-09-09

    In a multiprocessor system, a central memory synchronization module coordinates memory synchronization requests responsive to memory access requests in flight, a generation counter, and a reclaim pointer. The central module communicates via point-to-point communication. The module includes a global OR reduce tree for each memory access requesting device, for detecting memory access requests in flight. An interface unit is implemented associated with each processor requesting synchronization. The interface unit includes multiple generation completion detectors. The generation count and reclaim pointer do not pass one another.

  7. Generation-based memory synchronization in a multiprocessor system with weakly consistent memory accesses

    Energy Technology Data Exchange (ETDEWEB)

    Ohmacht, Martin

    2017-08-15

    In a multiprocessor system, a central memory synchronization module coordinates memory synchronization requests responsive to memory access requests in flight, a generation counter, and a reclaim pointer. The central module communicates via point-to-point communication. The module includes a global OR reduce tree for each memory access requesting device, for detecting memory access requests in flight. An interface unit is implemented associated with each processor requesting synchronization. The interface unit includes multiple generation completion detectors. The generation count and reclaim pointer do not pass one another.

  8. Kadomtsev-Petviashvili solitons propagation in a plasma system with superthermal and weakly relativistic effects

    Energy Technology Data Exchange (ETDEWEB)

    Hafeez-Ur-Rehman; Mahmood, S. [Theoretical Plasma Physics Division, PINSTECH, P.O. Nilore, Islamabad (Pakistan); Department of Physics and Applied Mathematics, PIEAS, Nilore, 44000 Islamabad (Pakistan); Shah, Asif; Haque, Q. [Theoretical Plasma Physics Division, PINSTECH, P.O. Nilore, Islamabad (Pakistan)

    2011-12-15

    Two dimensional (2D) solitons are studied in a plasma system comprising of relativistically streaming ions, kappa distributed electrons, and positrons. Kadomtsev-Petviashvili (KP) equation is derived through the reductive perturbation technique. Analytical solution of the KP equation has been studied numerically and graphically. It is noticed that kappa parameters of electrons and positrons as well as the ions relativistic streaming factor have an emphatic influence on the structural as well as propagation characteristics of two dimensional solitons in the considered plasma system. Our results may be helpful in the understanding of soliton propagation in astrophysical and laboratory plasmas, specifically the interaction of pulsar relativistic wind with supernova ejecta and the transfer of energy to plasma by intense electric field of laser beams producing highly energetic superthermal and relativistic particles [L. Arons, Astrophys. Space Sci. Lib. 357, 373 (2009); P. Blasi and E. Amato, Astrophys. Space Sci. Proc. 2011, 623; and A. Shah and R. Saeed, Plasma Phys. Controlled Fusion 53, 095006 (2011)].

  9. Energy transport in weakly nonlinear wave systems with narrow frequency band excitation.

    Science.gov (United States)

    Kartashova, Elena

    2012-10-01

    A novel discrete model (D model) is presented describing nonlinear wave interactions in systems with small and moderate nonlinearity under narrow frequency band excitation. It integrates in a single theoretical frame two mechanisms of energy transport between modes, namely, intermittency and energy cascade, and gives the conditions under which each regime will take place. Conditions for the formation of a cascade, cascade direction, conditions for cascade termination, etc., are given and depend strongly on the choice of excitation parameters. The energy spectra of a cascade may be computed, yielding discrete and continuous energy spectra. The model does not require statistical assumptions, as all effects are derived from the interaction of distinct modes. In the example given-surface water waves with dispersion function ω(2)=gk and small nonlinearity-the D model predicts asymmetrical growth of side-bands for Benjamin-Feir instability, while the transition from discrete to continuous energy spectrum, excitation parameters properly chosen, yields the saturated Phillips' power spectrum ~g(2)ω(-5). The D model can be applied to the experimental and theoretical study of numerous wave systems appearing in hydrodynamics, nonlinear optics, electrodynamics, plasma, convection theory, etc.

  10. Fourier–Hermite spectral representation for the Vlasov–Poisson system in the weakly collisional limit

    KAUST Repository

    Parker, Joseph T.

    2015-02-03

    Copyright © Cambridge University Press 2015. We study Landau damping in the 1+1D Vlasov-Poisson system using a Fourier-Hermite spectral representation. We describe the propagation of free energy in Fourier-Hermite phase space using forwards and backwards propagating Hermite modes recently developed for gyrokinetic theory. We derive a free energy equation that relates the change in the electric field to the net Hermite flux out of the zeroth Hermite mode. In linear Landau damping, decay in the electric field corresponds to forward propagating Hermite modes; in nonlinear damping, the initial decay is followed by a growth phase characterized by the generation of backwards propagating Hermite modes by the nonlinear term. The free energy content of the backwards propagating modes increases exponentially until balancing that of the forward propagating modes. Thereafter there is no systematic net Hermite flux, so the electric field cannot decay and the nonlinearity effectively suppresses Landau damping. These simulations are performed using the fully-spectral 5D gyrokinetics code SpectroGK, modified to solve the 1+1D Vlasov-Poisson system. This captures Landau damping via Hou-Li filtering in velocity space. Therefore the code is applicable even in regimes where phase mixing and filamentation are dominant.

  11. Muscle Weakness

    Science.gov (United States)

    Al Kaissi, Ali; Ryabykh, Sergey; Ochirova, Polina; Kenis, Vladimir; Hofstätter, Jochen G.; Grill, Franz; Ganger, Rudolf; Kircher, Susanne Gerit

    2017-01-01

    Marked ligamentous hyperlaxity and muscle weakness/wasting associated with awkward gait are the main deficits confused with the diagnosis of myopathy. Seven children (6 boys and 1 girl with an average age of 8 years) were referred to our department because of diverse forms of skeletal abnormalities. No definitive diagnosis was made, and all underwent a series of sophisticated investigations in other institutes in favor of myopathy. We applied our methodology through the clinical and radiographic phenotypes followed by targeted genotypic confirmation. Three children (2 boys and 1 girl) were compatible with the diagnosis of progressive pseudorheumatoid chondrodysplasia. The genetic mutation was correlated with the WISP 3 gene actively expressed by articular chondrocytes and located on chromosome 6. Klinefelter syndrome was the diagnosis in 2 boys. Karyotyping confirmed 47,XXY (aneuploidy of Klinefelter syndrome). And 2 boys were finally diagnosed with Morquio syndrome (MPS type IV A) as both showed missense mutations in the N-acetylgalactosamine-sulfate sulfatase gene. Misdiagnosis can lead to the initiation of a long list of sophisticated investigations. PMID:28210640

  12. Biomimetic Sensors: Active Electrolocation of Weakly Electric Fish as a Model for Active Sensing in Technical Systems

    Institute of Scientific and Technical Information of China (English)

    Gerhard von der Emde

    2007-01-01

    Instead of vision, many nocturnal animals use alternative senses for navigation and object detection in their dark environment. For this purpose, weakly electric mormyrid fish employ active electrolocation, during which they discharge a specialized electric organ in their tail which discharges electrical pulses. Each discharge builds up an electrical field around the fish, which is sensed by cutaneous electroreceptor organs that are distributed over most of the body surface of the fish. Nearby objects distort this electrical field and cause a local alteration in current flow in those electroreceptors that are closest to the object. By constantly monitoring responses of its electroreceptor organs, a fish can detect, localize, and identify environmental objects.Inspired by the remarkable capabilities of weakly electric fish in detecting and recognizing objects, we designed technical sensor systems that can solve similar problems of remote object sensing. We applied the principles of active electrolocation to technical systems by building devices that produce electrical current pulses in a conducting medium (water or ionized gases) and simultaneously sense local current density. Depending on the specific task a sensor was designed for devices could (i) detect an object, (ii) localize it in space, (iii) determine its distance, and (iv) measure properties such as material properties, thickness, or material faults. Our systems proved to be relatively insensitive to environmental disturbances such as heat, pressure, or turbidity. They have a wide range of applications including material identification, quality control, non-contact distance measurements, medical applications and many more. Despite their astonishing capacities, our sensors still lag far behind what electric fish are able to achieve during active electrolocation. The understanding of the neural principles governing electric fish sensory physiology and the corresponding optimization of our sensors to solve

  13. Collapse of the wave field in a one-dimensional system of weakly coupled light guides

    Science.gov (United States)

    Balakin, A. A.; Litvak, A. G.; Mironov, V. A.; Skobelev, S. A.

    2016-12-01

    The analytical and numerical study of the radiation self-action in a system of coupled light guides is fulfilled on the basis of the discrete nonlinear Schrödinger equation (DNSE). We develop a variational method for qualitative study of DNSE and classify self-action modes. We show that the diffraction of narrow (in grating scale) wave beams weakens in discrete media and, consequently, the "collapse" of the one-dimensional wave field with power exceeding the critical value occurs. This results in the ability to self-channel radiation in the central fiber. Qualitative analytical results were confirmed by numerical simulation of DNSE, which also shows the stability of the collapse mode.

  14. Stochastic Stability for Time-Delay Markovian Jump Systems with Sector-Bounded Nonlinearities and More General Transition Probabilities

    Directory of Open Access Journals (Sweden)

    Dan Ye

    2013-01-01

    Full Text Available This paper is concerned with delay-dependent stochastic stability for time-delay Markovian jump systems (MJSs with sector-bounded nonlinearities and more general transition probabilities. Different from the previous results where the transition probability matrix is completely known, a more general transition probability matrix is considered which includes completely known elements, boundary known elements, and completely unknown ones. In order to get less conservative criterion, the state and transition probability information is used as much as possible to construct the Lyapunov-Krasovskii functional and deal with stability analysis. The delay-dependent sufficient conditions are derived in terms of linear matrix inequalities to guarantee the stability of systems. Finally, numerical examples are exploited to demonstrate the effectiveness of the proposed method.

  15. EXISTENCE OF BOUNDED SOLUTIONS ON THE REAL LINE FOR LIENARD SYSTEM

    Institute of Scientific and Technical Information of China (English)

    肖海滨

    2003-01-01

    The existence of monotone and non-monotone solutions of boundary value problem on the real line for Lienard equation is studied. Applying the theory of planar dynamical systems and the comparison method of vector fields defined by Lienard system and the system given by symmetric transformation or quasi-symmetric transformation, the invariant regions of the system are constructed. The existence of connecting orbits can be proved. A lot of sufficient conditions to guarantee the existence of solutions of the boundary value problem are obtained. Especially, when the source function is bi-stable, the existence of infinitely many monotone solusion is obtained.

  16. Stochastic bounded consensus tracking of leader-follower multi-agent systems with measurement noises and sampled-data

    Institute of Scientific and Technical Information of China (English)

    Wu Zhi-Hai; Peng Li; Xie Lin-Bo; Wen Ji-Wei

    2012-01-01

    This paper is concerned with the stochastic bounded consensus tracking problems of leader-follower multi-agent systems,where the control input of an agent can only use the information measured at the sampling instants from its neighbours or the virtual leader with a time-varying reference state,and the measurements are corrupted by random noises.The probability limit theory and the algebra graph theory are employed to derive the necessary and sufficient conditions guaranteeing the mean square bounded consensus tracking.It is shown that the maximum allowable upper boundary of the sampling period simultaneously depends on the constant feedback gains and the network topology.Furthermore,the effects of the sampling period on the tracking performance are analysed.It turns out that from the view point of the sampling period,there is a trade-off between the tracking speed and the static tracking error.Simulations are provided to demonstrate the effectiveness of the theoretical results.

  17. Ray equations of a weak shock in a hyperbolic system of conservation laws in multi-dimensions

    Indian Academy of Sciences (India)

    Phoolan Prasad

    2016-05-01

    In this paper we give a complete proof of a theorem, which states that ‘for a weak shock, the shock ray velocity is equal to the mean of the ray velocities of nonlinear wavefronts just ahead and just behind the shock, provided we take the wavefronts ahead and behind to be instantaneously coincident with the shock front. Similarly, the rate of turning of the shock front is also equal to the mean of the rates of turning of such wavefronts just ahead and just behind the shock’. A particular case of this theorem for shock propagation in gasdynamics has been used extensively in applications. Since it is useful also in other physical systems, we present here the theorem in its most general form.

  18. Effect of Weaknesses of the Internal Control Systems And NonCompliance With Statutory Provisions on The Audit opinion of The Audit Board of The Republic of Indonesia

    Directory of Open Access Journals (Sweden)

    Hari Setiyawati

    2016-09-01

    Full Text Available The purpose of this study was to see whether there is an influence of Weaknesses of the Internal Control System and Non-compliance With Statutory Provisions on the audit opinion of the audit board. The weakness of the internal control system measured by the audit findings Audit Board consisting of weaknesses of the accounting control system and reporting, and weaknesses of the budget implementation control system and weaknesses of the internal control structure. While non-compliance with statutory provisions are measured based on the audit findings Audit Board consisting of local loss, the potential loss of local , lack of receipt, administration, waste, inefficiency and ineffectiveness. This study is a survey of the region of the provincial government of DKI Jakarta and Banten for 2010 to 2014. Samples in this study were all the Local Government Unit that generate financial reports of local governments totaling nine units, so this study is census research, in the sense that the entire population sampled. Data analysis method used is the ordinal logistic regression because the dependent variable is the rank (category and the data is not normal. From the results of the data analysis and discussion, it can be concluded that the weaknesses of the internal control system and non-compliance with statutory provisions affect the audit opinion of the audit board either jointly or partially

  19. Feedback control of time-delay systems with bounded control and state

    Directory of Open Access Journals (Sweden)

    M. Dambrine

    1995-01-01

    Full Text Available This paper is concerned with the problem of stabilizing linear time-delay systems under state and control linear constraints. For this, necessary and sufficient conditions for a given non-symmetrical polyhedral set to be positively invariant are obtained. Then existence conditions of linear state feedback control law respecting the constraints are established, and a procedure is given in order to calculate such a controller. The paper concerns memoryless controlled systems but the results can be applied to cases of delayed controlled systems. An example is given.

  20. Weakly tight functions and their decomposition

    Directory of Open Access Journals (Sweden)

    Mona Khare

    2005-01-01

    Full Text Available The present paper deals with the study of a weakly tight function and its relation to tight functions. We obtain a Jordan-decomposition-type theorem for a locally bounded weakly tight real-valued function defined on a sublattice of IX, followed by the notion of a total variation.

  1. A Chinese literature overview on ultra-weak photon emission as promising technology for studying system-based diagnostics.

    Science.gov (United States)

    He, Min; Sun, Mengmeng; van Wijk, Eduard; van Wietmarschen, Herman; van Wijk, Roeland; Wang, Zhihong; Wang, Mei; Hankemeier, Thomas; van der Greef, Jan

    2016-04-01

    To present the possibilities pertaining to linking ultra-weak photon emission (UPE) with Chinese medicine-based diagnostics principles, we conducted a review of Chinese literature regarding UPE with respect to a systems view of diagnostics. Data were summarized from human clinical studies and animal models published from 1979 through 1998. The research fields can be categorized as follows: (1) human physiological states measured using UPE; (2) characteristics of human UPE in relation to various pathological states; and (3) the relationship between diagnosis (e.g., Chinese syndromes) and the dynamics of UPE in animal models. We conclude that UPE has clear potential in terms of understanding the systems view on health and disease as described using Chinese medicine-based diagnostics, particularly from a biochemistry-based regulatory perspective. Linking UPE with metabolomics can further bridge biochemistry-based Western diagnostics with the phenomenology-based Chinese diagnostics, thus opening new avenues for studying systems diagnostics in the early stage of disease, for prevention-based strategies, as well as for systems-based intervention in chronic disease.

  2. The Weak Expectation Property and Riesz Interpolation

    CERN Document Server

    Kavruk, Ali S

    2012-01-01

    We show that Lance's weak expectation property is connected to tight Riesz interpolations in lattice theory. More precisely we first prove that if A \\subset B(H) is a unital C*-subalgebra, where B(H) is the bounded linear operators on a Hilbert space H, then A has (2,2) tight Riesz interpolation property in B(H) (defined below). An extension of this requires an additional assumption on A: A has (2,3) tight Riesz interpolation property in B(H) at every matricial level if and only if A has the weak expectation property. Let $J = span{(1,1,-1,-1,-1)}$ in $C^5$ . We show that a unital C*-algebra A has the weak expectation property if and only if $A \\otimesmin (C^5/J) = A \\otimesmax (C^5/J)$ (here \\otimesmin and \\otimesmax are the minimal and the maximal operator system tensor products, respectively, and $C^5/J$ is the operator system quotient of $C^5$ by $J$). We express the Kirchberg conjecture (KC) in terms of a four dimensional operator system problem. We prove that KC has an affirmative answer if and only if ...

  3. Hyperspherical three-body model calculation for the bound $^{1,3}$S-states of Coulombic systems

    CERN Document Server

    Khan, Md Abdul

    2014-01-01

    In this paper, hyperspherical three-body model formalism has been applied for the calculation energies of the low-lying bound $^{1,3}$S (L=0)-states of neutral helium and helium like Coulombic three-body systems having nuclear charge (Z) in the range Z=2 to Z=92. The calculation of the coupling potential matrix elements of the two-body potentials has been simplified by the introduction of Raynal-Revai Coefficients (RRC). The three-body wave function in the Schr\\H{o}dinger equation when expanded in terms of hyperpherical harmonics (HH), leads to an infinite set of coupled differential equation (CDE). For practical reason the infinite set of CDE is truncated to a finite set and are solved by an exact numerical method known as renormalized Numerov method (RNM) to get the energy solution (E). The calculated energy is compared with the ones of the literature.

  4. IDENTIFICATION ERROR BOUNDS AND ASYMPTOTIC DISTRIBUTIONS FOR SYSTEMS WITH STRUCTURAL UNCERTAINTIES

    Institute of Scientific and Technical Information of China (English)

    Gang George YIN; Shaobai KAN; Le Yi WANG

    2006-01-01

    This work is concerned with identification of systems that are subject to not only measurement noises, but also structural uncertainties such as unmodeled dynamics, sensor nonlinear mismatch,and observation bias. Identification errors are analyzed for their dependence on these structural uncertainties. Asymptotic distributions of scaled sequences of estimation errors are derived.

  5. "Bound" globulin in the skin of patients with chronic discoid lupus erythematosus and systemic lupus erythematosus

    NARCIS (Netherlands)

    Cormane, R.H.

    1964-01-01

    In what respect chronic discoid lupus erythematosus is related to systemic lupus erythematosus is still uncertain. In discoid lupus the lupus-erythematosus (L.E.) phenomenon is negative, and the history does not suggest vascular lesions or involvement of serous membranes. In both diseases the pathog

  6. On bounded block decomposition problems for under-specified systems of equations

    NARCIS (Netherlands)

    Bomhoff, Matthijs; Kern, Walter; Still, Georg

    2012-01-01

    When solving a system of equations, it can be beneficial not to solve it in its entirety at once, but rather to decompose it into smaller subsystems that can be solved in order. Based on a bisimplicial graph representation we analyze the parameterized complexity of two problems central to such a dec

  7. "Bound" globulin in the skin of patients with chronic discoid lupus erythematosus and systemic lupus erythematosus

    NARCIS (Netherlands)

    Cormane, R.H.

    1964-01-01

    In what respect chronic discoid lupus erythematosus is related to systemic lupus erythematosus is still uncertain. In discoid lupus the lupus-erythematosus (L.E.) phenomenon is negative, and the history does not suggest vascular lesions or involvement of serous membranes. In both diseases the

  8. "Bound" globulin in the skin of patients with chronic discoid lupus erythematosus and systemic lupus erythematosus

    NARCIS (Netherlands)

    Cormane, R.H.

    1964-01-01

    In what respect chronic discoid lupus erythematosus is related to systemic lupus erythematosus is still uncertain. In discoid lupus the lupus-erythematosus (L.E.) phenomenon is negative, and the history does not suggest vascular lesions or involvement of serous membranes. In both diseases the pathog

  9. Weak, strong, and uniform quantum simulations

    Science.gov (United States)

    Wang, Dong-Sheng

    2015-01-01

    In this work, we introduce different types of quantum simulations according to different operator topologies on a Hilbert space, namely, uniform, strong, and weak quantum simulations. We show that they have the same computational power that the efficiently solvable problems are in bounded-error quantum polynomial time. For the weak simulation, we formalize a general weak quantum simulation problem and construct an algorithm which is valid for all instances. Also, we analyze the computational power of quantum simulations by proving the query lower bound for simulating a general quantum process.

  10. Visualization of Load Security Region Bounded by Operational Constraints of Power Systems

    Directory of Open Access Journals (Sweden)

    Sotdhipong Phichaisawat

    2011-07-01

    Full Text Available This paper presents the method to visualize a set of feasible loading points, called “feasible region”, in the two-dimensional power flow solution space. The visualization can be done by tracing the boundary of feasible region. The boundary points are determined by optimizing the reduced cost function with operational constraints. The method can also determine several kinds of feasible regions by assigning the appropriate free variables and its criteria. These feasible regions show the robustness of operating points and the limit of control actions. The six-bus test system illustrates the boundary tracing and impacts of system parameters on the shape of feasible region, i.e. the capacitor bank operation, load shedding, generator voltage controls, and load level.

  11. On bounded and unbounded dynamics of the Hamiltonian system for unified scalar field cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Starkov, Konstantin E., E-mail: kstarkov@ipn.mx

    2016-05-27

    This paper is devoted to the research of global dynamics for the Hamiltonian system formed by the unified scalar field cosmology. We prove that this system possesses only unbounded dynamics in the space of negative curvature. It is found the invariant domain filled only by unbounded dynamics for the space with positive curvature. Further, we construct a set of polytopes depending on the Hamiltonian level surface that contain all compact invariant sets. Besides, one invariant two dimensional plane is described. Finally, we establish nonchaoticity of dynamics in one special case. - Highlights: • Unbounded dynamics is stated in case of negative curvature. • Domain with unbounded dynamics is got in case of positive curvature. • Localization polytope for compact invariant sets is computed. • One two dimensional invariant plane is described. • Nonchaotic dynamics is stated in one special case.

  12. Aspects of Majorana Bound States in One-Dimensional Systems with and without Time-Reversal Symmetry

    DEFF Research Database (Denmark)

    Wölms, Konrad Udo Hannes

    bound states in the measurement still has to be understood better. And example would be the frequently performed tunnel probe measurement on Majorana bound states [26, 40, 41]. A second reason why Majorana bound states are interesting is their potential application to a certain quantum computation...... scheme. This scheme, called topological quantum computation, relies on the braiding of so-called non-abelian anyons in order to perform computations [18]. Majorana bound states are the simplest example of such non-abelian anyons. No other non-abelian anyons have been realized experimentally yet, which...... puts further focus on the study of Majorana bound states. Additionally to probing Majorana bound states, their use in topological quantum computation also requires them to be manipulated. This also poses an interesting problem for both experimentalists and theorists [25, 27]. We can summarize...

  13. VISCO-ELASTIC SYSTEMS UNDER BOTH DETERMINISTIC AND BOUND RANDOM PARAMETRIC EXCITATION

    Institute of Scientific and Technical Information of China (English)

    徐伟; 戎海武; 方同

    2003-01-01

    The principal resonance of a visco-elastic systems under both deterministic and random parametric excitation was investigated. The method of multiple scales was used to determine the equations of modulation of amplitude and phase. The behavior, stability and bifurcation of steady state response were studied by means of qualitative analysis. The contributions from the visco-elastic force to both damping and stiffness can be taken into account. The effects of damping, detuning, bandwidth, and magnitudes of deterministic and random excitations were analyzed. The theoretical analysis is verified by numerical results.

  14. Bounded Rationality

    Directory of Open Access Journals (Sweden)

    Ballester Pla, Coralio

    2012-03-01

    Full Text Available The observation of the actual behavior by economic decision makers in the lab and in the field justifies that bounded rationality has been a generally accepted assumption in many socio-economic models. The goal of this paper is to illustrate the difficulties involved in providing a correct definition of what a rational (or irrational agent is. In this paper we describe two frameworks that employ different approaches for analyzing bounded rationality. The first is a spatial segregation set-up that encompasses two optimization methodologies: backward induction and forward induction. The main result is that, even under the same state of knowledge, rational and non-rational agents may match their actions. The second framework elaborates on the relationship between irrationality and informational restrictions. We use the beauty contest (Nagel, 1995 as a device to explain this relationship.

    La observación del comportamiento de los agentes económicos tanto en el laboratorio como en la vida real justifica que la racionalidad acotada sea un supuesto aceptado en numerosos modelos socio-económicos. El objetivo de este artículo es ilustrar las dificultades que conlleva una correcta definición de qué es un agente racional (irracional. En este artículo se describen dos marcos que emplean diferentes metodologías para analizar la racionalidad acotada. El primero es un modelo de segregación espacial donde se contrastan dos metodologías de optimización: inducción hacia atrás y hacia adelante. El resultado principal es que, incluso con el mismo nivel de conocimiento, tanto agentes racionales como irracionales podrían coincidir en sus acciones. El segundo marco trabaja sobre la relación entre irracionalidad y restricción de información. Se utiliza el juego llamado “beauty contest” (Nagel 1995 como mecanismo para explicar dicha relación.

  15. Using the DFT-D method to describe dispersion interactions in systems of weakly-bonded Xe-aromatic molecules

    Science.gov (United States)

    Andriichenko, N. N.; Ermilov, A. Yu.

    2013-08-01

    The optimum version of the DFT-D class of methods (BHHLYP-D2, 6-31G*) is chosen to describe binding in a Xe-phenol system with the aim of subsequent KM/MM calculations for complex Xe-containing protein systems. It is shown that the stability of the Xe-phenol system is due to weak dispersion interactions not described in conventional approaches using the density functional. The MP2 approach using the (aug)-cc-pVTZ basis and Stuttgart pseudopotential, which yield the best reproduction of the characteristics of a Xe2 xenon dimer, is chosen as the reference standard. It is noted that the 2010 DFT-D3 methods underestimate the binding energy by a factor of nearly three, while DFT methods without dispersion corrections do not reproduce the stability of Xe2 and Xe-phenol systems. It is found that in the best version of calculations, BHHLYP-D2, the binding energy in Xe-phenol complex is estimated to be 2.7 kcal/mol versus the 3.1 kcal/mol found using the comparative approach. It is concluded that BHHLYP-D2 adequately reproduces the difference between the two conformers of the Xe-phenol complex and trend toward an increase in binding energy in the series of aromatic amino acids (phenylalanine, tyrosine, and tryptophan). DFT-D can also indicate the existence of excess conformers that are missing in systems according to more precise descriptions (MP2/(aug)-cc-pVTZ).

  16. Elastic scattering, muon transfer, bound states and resonances in the three-body mesic molecular systems in the reduced adiabatic hyperspherical approach

    Science.gov (United States)

    Abramov, D. I.; Gusev, V. V.; Ponomarev, L. I.

    1999-06-01

    The uniform method of numerical investigation of bound states and scattering processes 2→ 2 (including resonance states) in the Coulomb three-body (CTB) systems is developed. It is based on the adiabatic hyperspherical approach (AHSA) and includes the numerical realization and applications to the three-body mesic atomic systems. The results of calculations of bound states of these systems (including the local characteristics of the wave functions) and the scattering processes 2→ 2 (including the characteristics of the resonance states) are presented.

  17. Elastic scattering, muon transfer, bound states and resonances in the three-body mesic molecular systems in the reduced adiabatic hyperspherical approach

    Energy Technology Data Exchange (ETDEWEB)

    Abramov, D.I. [St.-Petersburg State University (Russian Federation); Gusev, V.V. [Institute for High Energy Physics (Russian Federation); Ponomarev, L.I. [Russian Research Center ' Kurchatov Institute' (Russian Federation)

    1999-06-15

    The uniform method of numerical investigation of bound states and scattering processes 2{sup {yields}} 2 (including resonance states) in the Coulomb three-body (CTB) systems is developed. It is based on the adiabatic hyperspherical approach (AHSA) and includes the numerical realization and applications to the three-body mesic atomic systems. The results of calculations of bound states of these systems (including the local characteristics of the wave functions) and the scattering processes 2{sup {yields}} 2 (including the characteristics of the resonance states) are presented.

  18. Weak interactions in clobazam-lactose mixtures examined by differential scanning calorimetry: Comparison with the captopril-lactose system

    Energy Technology Data Exchange (ETDEWEB)

    Toscani, S. [Departement de Chimie - UMR 6226, Faculte des Sciences, Universite de Rennes 1, Batiment 10B, 263 avenue du General Leclerc, F-35042 Rennes Cedex (France); Cornevin, L. [Universite de Rennes 1, Faculte de Pharmacie, 2 Avenue Leon Bernard, F-35043 Rennes Cedex (France); Burgot, G., E-mail: Gwenola.burgot@univ-rennes1.fr [Universite de Rennes 1, Faculte de Pharmacie, Laboratoire de Chimie Analytique, EA 1274 ' Mouvement, sports, sante' , 2 Avenue Leon Bernard, F-35043 Rennes Cedex (France); CHGR Rennes, Pole Medico-Technique Pharmacie, F-35703 Rennes Cedex (France)

    2012-09-10

    Highlights: Black-Right-Pointing-Pointer Thermodynamic and kinetic parameters of weak interactions in binary systems by DSC. Black-Right-Pointing-Pointer Energy-barrier decrease for lactose dehydration induced by clobazam. Black-Right-Pointing-Pointer Recrystallisation of metastable liquid clobazam induced by anhydrous alpha lactose. Black-Right-Pointing-Pointer Decrease of lactose dehydration temperature in binary mixtures with captopril. Black-Right-Pointing-Pointer Increase of lactose dehydration enthalpy in binary mixtures with captopril. - Abstract: The thermal behaviour of binary mixtures of two drugs (clobazam and captopril, respectively) and a pharmaceutical excipient (lactose monohydrate) was measured with differential scanning calorimetry to determine thermodynamic and kinetic parameters (dehydration and melting enthalpies and dehydration and glass-transition activation energies) which might be affected by intermolecular interactions. A kinetic study showed that lactose dehydration is not a single-step conversion and that clobazam contributed to reduce the energy barrier for the bulk dehydration of the excipient. On the other hand, the physical interactions between metastable liquid clobazam and crystalline anhydrous {alpha}-lactose obtained from monohydrate dehydration gave rise to the recrystallisation of clobazam. In the captopril-lactose system, the liquid captopril influenced the lactose dehydration: a sharp increase of the dehydration enthalpy and a concurrent reduction of the dehydration temperature were observed. Finally, it turned out that solid-phase transitions were enhanced by the contact with a liquid phase.

  19. The influence of a weak magnetic field in the Renormalization-Group functions of (2 + 1)-dimensional Dirac systems

    Science.gov (United States)

    Menezes, Natália; Alves, Van Sérgio; Smith, Cristiane Morais

    2016-12-01

    The experimental observation of the renormalization of the Fermi velocity v F as a function of doping has been a landmark for confirming the importance of electronic interactions in graphene. Although the experiments were performed in the presence of a perpendicular magnetic field B, the measurements are well described by a renormalization-group (RG) theory that did not include it. Here we clarify this issue, for both massive and massless Dirac systems, and show that for the weak magnetic fields at which the experiments are performed, there is no change in the renormalization-group functions. Our calculations are carried out in the framework of the Pseudo-quantum electrodynamics (PQED) formalism, which accounts for dynamical interactions. We include only the linear dependence in B, and solve the problem using two different parametrizations, the Feynman and the Schwinger one. We confirm the results obtained earlier within the RG procedure and show that, within linear order in the magnetic field, the only contribution to the renormalization of the Fermi velocity for the massive case arises due to electronic interactions. In addition, for gapped systems, we observe a running of the mass parameter.

  20. Renormalization of weak noises of arbitrary shape for one-dimensional critical dynamical systems Announcement of results and numerical explorations

    CERN Document Server

    Diaz-Espinosa, O

    2006-01-01

    We study the effect of noise on one--dimensional critical dynamical systems (that is, maps with a renormalization theory). We consider in detail two examples of such dynamical systems: unimodal maps of the interval at the accumulation of period--doubling and smooth homeomorphisms of the circle with a critical point and with golden mean rotation number. We show that, if we scale the space and the time, several properties of the noise (the cumulants or Wick--ordered moments) satisfy some scaling relations. A consequence of the scaling relations is that a version of the central limit theorem holds. Irrespective of the shape of the initial noise, if the bare noise is weak enough, the effective noise becomes close to Gaussian in several senses that we can make precise. We notice that the conclusions are false for maps with positive Lyapunov exponents. The method of analysis is close in spirit to the study of scaling limits in renormalization theory. We also perform several numerical experiments that confirm the ri...