Parallel coupling of symmetric and asymmetric exclusion processes
International Nuclear Information System (INIS)
Tsekouras, K; Kolomeisky, A B
2008-01-01
A system consisting of two parallel coupled channels where particles in one of them follow the rules of totally asymmetric exclusion processes (TASEP) and in another one move as in symmetric simple exclusion processes (SSEP) is investigated theoretically. Particles interact with each other via hard-core exclusion potential, and in the asymmetric channel they can only hop in one direction, while on the symmetric lattice particles jump in both directions with equal probabilities. Inter-channel transitions are also allowed at every site of both lattices. Stationary state properties of the system are solved exactly in the limit of strong couplings between the channels. It is shown that strong symmetric couplings between totally asymmetric and symmetric channels lead to an effective partially asymmetric simple exclusion process (PASEP) and properties of both channels become almost identical. However, strong asymmetric couplings between symmetric and asymmetric channels yield an effective TASEP with nonzero particle flux in the asymmetric channel and zero flux on the symmetric lattice. For intermediate strength of couplings between the lattices a vertical-cluster mean-field method is developed. This approximate approach treats exactly particle dynamics during the vertical transitions between the channels and it neglects the correlations along the channels. Our calculations show that in all cases there are three stationary phases defined by particle dynamics at entrances, at exits or in the bulk of the system, while phase boundaries depend on the strength and symmetry of couplings between the channels. Extensive Monte Carlo computer simulations strongly support our theoretical predictions. Theoretical calculations and computer simulations predict that inter-channel couplings have a strong effect on stationary properties. It is also argued that our results might be relevant for understanding multi-particle dynamics of motor proteins
National simple: Constitutionality Analysis of Exclusions Sectorial
Directory of Open Access Journals (Sweden)
Guilherme Adolfo dos Santos Mendes
2016-06-01
Full Text Available The Constitution defines the favored legal treatment for small businesses without making any explicit exception, including and especially for tax obligations. Nevertheless, all the laws, which have introduced tax benefits guided by this higher provision, have discriminated small companies due to the economic sector of activity. Known as “National Simple” and introduced by the Complementary Law No. 123/06, the current legislation did not extend its benefits to small production units of a number of industries, such as the automotive industry, the passenger transport industry, the energy industry and the industry of manufacture of weapons, beverages and tobacco products. By demonstrating the mistakes of the arguments in favor of such exclusions, the article holds up that none of these provisions meets constitutional standards. Furthermore, based on a critical analysis of the Positive Law, it is shown that the hidden desire behind the exclusions was to keep the economic sectors of high profitability under control of big corporations to the detriment of smaller initiatives.
Two-channel totally asymmetric simple exclusion processes
International Nuclear Information System (INIS)
Pronina, Ekaterina; Kolomeisky, Anatoly B
2004-01-01
Totally asymmetric simple exclusion processes, consisting of two coupled parallel lattice chains with particles interacting with hard-core exclusion and moving along the channels and between them, are considered. In the limit of strong coupling between the channels, the particle currents, density profiles and a phase diagram are calculated exactly by mapping the system into an effective one-channel totally asymmetric exclusion model. For intermediate couplings, a simple approximate theory, that describes the particle dynamics in vertical clusters of two corresponding parallel sites exactly and neglects the correlations between different vertical clusters, is developed. It is found that, similarly to the case of one-channel totally asymmetric simple exclusion processes, there are three stationary state phases, although the phase boundaries and stationary properties strongly depend on inter-channel coupling. Extensive computer Monte Carlo simulations fully support the theoretical predictions
Energy Technology Data Exchange (ETDEWEB)
Sun, Xiaoyan, E-mail: sunxiaoyan1@gmail.com [College of Physics and Electronic Engineering, Guangxi Teacher Education University, Nanning 530001 (China); Xie, Yanbo [Department of Modern Physics, University of Science and Technology of China, Hefei 230026 (China); He, Zhiwei [College of Science, China Agricultural University, Beijing 100083 (China); Wang, Binghong [Department of Modern Physics, University of Science and Technology of China, Hefei 230026 (China)
2011-07-11
This Letter investigates a totally asymmetric simple exclusion process (TASEP) with junctions in a one-dimensional transport system. Parallel update rules and periodic boundary condition are adopted. Two cases corresponding to different update rules are studied. The results show that the stationary states of system mainly depend on the selection behavior of particle at the bifurcation point. -- Highlights: → For no preference case, the system exists three stationary phases. → For preference case, the system exists five stationary phases. → The road lengths have not qualitative influence on the fundamental diagram.
SIMPLE MODELS OF THREE COUPLED PT -SYMMETRIC WAVE GUIDES ALLOWING FOR THIRD-ORDER EXCEPTIONAL POINTS
Directory of Open Access Journals (Sweden)
Jan Schnabel
2017-12-01
Full Text Available We study theoretical models of three coupled wave guides with a PT-symmetric distribution of gain and loss. A realistic matrix model is developed in terms of a three-mode expansion. By comparing with a previously postulated matrix model it is shown how parameter ranges with good prospects of finding a third-order exceptional point (EP3 in an experimentally feasible arrangement of semiconductors can be determined. In addition it is demonstrated that continuous distributions of exceptional points, which render the discovery of the EP3 difficult, are not only a feature of extended wave guides but appear also in an idealised model of infinitely thin guides shaped by delta functions.
Ebrahim Foulaadvand, M.; Chaaboki, Sanaz; Saalehi, Modjtaba
2007-01-01
We investigate the effect of quenched spatial disordered hopping rates on the characteristics of the asymmetric simple exclusion process with open boundaries both numerically and by extensive simulations. Disorder averages of the bulk density and current are obtained in terms of various input and output rates. We study the binary and uniform distributions of disorder. It is verified that the effect of spatial inhomogeneity is generically to enlarge the size of the maximal-current phase. This is in accordance with the mean-field results obtained by Harris and Stinchcombe [Phys. Rev. E 70, 016108 (2004)]. Furthermore, we obtain the dependence of the current and the bulk density on the characteristics of the disorder distribution function. It is shown that the impact of disorder crucially depends on the particle input and out rates. In some situations, disorder can constructively enhance the current.
Directory of Open Access Journals (Sweden)
Nikolay M. Bogoliubov
2009-04-01
Full Text Available The basic model of the non-equilibrium low dimensional physics the so-called totally asymmetric exclusion process is related to the 'crystalline limit' (q → ∞ of the SU_q(2 quantum algebra. Using the quantum inverse scattering method we obtain the exact expression for the time-dependent stationary correlation function of the totally asymmetric simple exclusion process on a one dimensional lattice with the periodic boundary conditions.
Arita, Chikashi; Foulaadvand, M Ebrahim; Santen, Ludger
2017-03-01
We consider the exclusion process on a ring with time-dependent defective bonds at which the hopping rate periodically switches between zero and one. This system models main roads in city traffics, intersecting with perpendicular streets. We explore basic properties of the system, in particular dependence of the vehicular flow on the parameters of signalization as well as the system size and the car density. We investigate various types of the spatial distribution of the vehicular density, and show existence of a shock profile. We also measure waiting time behind traffic lights, and examine its relationship with the traffic flow.
Mukherji, Sutapa
2018-03-01
In this paper, we study a one-dimensional totally asymmetric simple exclusion process with position-dependent hopping rates. Under open boundary conditions, this system exhibits boundary-induced phase transitions in the steady state. Similarly to totally asymmetric simple exclusion processes with uniform hopping, the phase diagram consists of low-density, high-density, and maximal-current phases. In various phases, the shape of the average particle density profile across the lattice including its boundary-layer parts changes significantly. Using the tools of boundary-layer analysis, we obtain explicit solutions for the density profile in different phases. A detailed analysis of these solutions under different boundary conditions helps us obtain the equations for various phase boundaries. Next, we show how the shape of the entire density profile including the location of the boundary layers can be predicted from the fixed points of the differential equation describing the boundary layers. We discuss this in detail through several examples of density profiles in various phases. The maximal-current phase appears to be an especially interesting phase where the boundary layer flows to a bifurcation point on the fixed-point diagram.
Olafsson, Gestur; Helgason, Sigurdur
1996-01-01
This book is intended to introduce researchers and graduate students to the concepts of causal symmetric spaces. To date, results of recent studies considered standard by specialists have not been widely published. This book seeks to bring this information to students and researchers in geometry and analysis on causal symmetric spaces.Includes the newest results in harmonic analysis including Spherical functions on ordered symmetric space and the holmorphic discrete series and Hardy spaces on compactly casual symmetric spacesDeals with the infinitesimal situation, coverings of symmetric spaces, classification of causal symmetric pairs and invariant cone fieldsPresents basic geometric properties of semi-simple symmetric spacesIncludes appendices on Lie algebras and Lie groups, Bounded symmetric domains (Cayley transforms), Antiholomorphic Involutions on Bounded Domains and Para-Hermitian Symmetric Spaces
Tsuzuki, Satori; Yanagisawa, Daichi; Nishinari, Katsuhiro
2018-04-01
This study proposes a model of a totally asymmetric simple exclusion process on a single-channel lane with functions of site assignments along the pit lane. The system model attempts to insert a new particle to the leftmost site at a certain probability by randomly selecting one of the empty sites in the pit lane, and reserving it for the particle. Thereafter, the particle is directed to stop at the site only once during its travel. Recently, the system was determined to show a self-deflection effect, in which the site usage distribution biases spontaneously toward the leftmost site, and the throughput becomes maximum when the site usage distribution is slightly biased to the rightmost site. Our exact analysis describes this deflection effect and show a good agreement with simulations.
International Nuclear Information System (INIS)
Krbalek, Milan; Hrabak, Pavel
2011-01-01
We consider the one-dimensional totally asymmetric simple exclusion process (TASEP model) with open boundary conditions and present the analytical computations leading to the exact formula for distance clearance distribution, i.e. probability density for a clear distance between subsequent particles of the model. The general relation is rapidly simplified for the middle part of the one-dimensional lattice. Both the analytical formulas and their approximations are compared with the numerical representation of the TASEP model. Such a comparison is presented for particles occurring in the internal part as well as in the boundary part of the lattice. Furthermore, we introduce the pertinent estimation for the so-called spectral rigidity of the model. The results obtained are sequentially discussed within the scope of vehicular traffic theory.
Zhou, Hui; Wuest, James D
2013-06-18
Linear D2h-symmetric bisisophthalic acids 1 and 2 and related substances have well-defined flattened structures, high affinities for graphite, and strong abilities to engage in specific intermolecular interactions. Their adsorption produces characteristic nanopatterns that reveal how 2D molecular organization can be controlled by reliable interadsorbate interactions such as hydrogen bonds when properly oriented by molecular geometry. In addition, the behavior of these compounds shows how large-scale organization can be obstructed by programming molecules to associate strongly according to competing motifs that have similar stability and can coexist smoothly without creating significant defects. Analogous new bisisophthalic acids 3a and 4a have similar associative properties, and their unique C2h-symmetric crankshaft geometry gives them the added ability to probe the poorly understood effect of chirality on molecular organization. Their adsorption shows how nanopatterns composed predictably of a single enantiomer can be obtained by depositing molecules that can respect established rules of association only by accepting neighbors of the same configuration. In addition, an analysis of the adsorption of crankshaft compounds 3a and 4a and their derivatives by STM reveals directly on the molecular level how kinetics and thermodynamics compete to control the crystallization of chiral compounds. In such ways, detailed studies of the adsorption of properly designed compounds on surfaces are proving to be a powerful way to discover and test rules that broadly govern molecular organization in both 2D and 3D.
International Nuclear Information System (INIS)
Perdomo, Rolando; Montero, Vivian
2006-01-01
Several methods for the extraction of endotoxin or lipopolysaccharide from Gram negative bacteria have been described. However, the product is often contaminated with nucleic acids or proteins in a proportion depending on the extraction method used. Molecular and immunological studies require further purification of the raw LPS. We present here, a simple method for the purification of raw LPS obtained by the standard hot phenol-water procedure using size exclusion chromatography in Sepharose CL-6B. We demonstrated that the using of DNAse and RNAse treatment of the sample before the chromatographic step is necessary to abrogate the nucleic acid contamination in the LPS fraction. The spectrophotometric properties of the pure LPS were verified, supporting the immediate online detection of the LPS and oligonucleotides fractions spectrophotometrically at 206 nm. The mobile phase used (NaCl 0.2 M) do not absorb at 206 nm while maintains the LPS aggregates and therefore, allows the separation of the LPS fraction from the oligoribonucleotide and desoxioligoribonucleotide fractions. The yield of pure LPS was around 98%. Chemical and biological characterizations were conducted in order to assess the feasibility of the procedure developed. (Author)
International Nuclear Information System (INIS)
Arnold, Polly L.; Cowie, Bradley E.; Suvova, Marketa; Zegke, Markus; Love, Jason B.; Magnani, Nicola; Colineau, Eric; Griveau, Jean-Christophe; Caciuffo, Roberto
2017-01-01
The reduction of U"V"I uranyl halides or amides with simple Ln"I"I or U"I"I"I salts forms highly symmetric, linear, oxo-bridged trinuclear U"V/Ln"I"I"I/U"V, Ln"I"I"I/U"I"V/Ln"I"I"I, and U"I"V/U"I"V/U"I"V complexes or linear Ln"I"I"I/U"V polymers depending on the stoichiometry and solvent. The reactions can be tuned to give the products of one- or two-electron uranyl reduction. The reactivity and magnetism of these compounds are discussed in the context of using a series of strongly oxo-coupled homo- and heterometallic poly(f-block) chains to better understand fundamental electronic structure in the f-block. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)
Energy Technology Data Exchange (ETDEWEB)
Arnold, Polly L.; Cowie, Bradley E.; Suvova, Marketa; Zegke, Markus; Love, Jason B. [EaStCHEM School of Chemistry, University of Edinburgh (United Kingdom); Magnani, Nicola; Colineau, Eric; Griveau, Jean-Christophe; Caciuffo, Roberto [European Commission, Directorate for Nuclear Safety and Security, Joint Research Centre, Karlsruhe (Germany)
2017-08-28
The reduction of U{sup VI} uranyl halides or amides with simple Ln{sup II} or U{sup III} salts forms highly symmetric, linear, oxo-bridged trinuclear U{sup V}/Ln{sup III}/U{sup V}, Ln{sup III}/U{sup IV}/Ln{sup III}, and U{sup IV}/U{sup IV}/U{sup IV} complexes or linear Ln{sup III}/U{sup V} polymers depending on the stoichiometry and solvent. The reactions can be tuned to give the products of one- or two-electron uranyl reduction. The reactivity and magnetism of these compounds are discussed in the context of using a series of strongly oxo-coupled homo- and heterometallic poly(f-block) chains to better understand fundamental electronic structure in the f-block. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)
Avena, L.; Hollander, den W.Th.F.; Redig, F.H.J.
2009-01-01
Consider a one-dimensional shift-invariant attractive spin-ip system in equilibrium, constituting a dynamic random environment, together with a nearest-neighbor random walk that on occupied sites has a local drift to the right but on vacant sites has a local drift to the left. In [2] we proved a law
Avena, L.; Hollander, den W.Th.F.; Redig, F.H.J.
2010-01-01
Consider a one-dimensional shift-invariant attractive spin-flip system in equilibrium, constituting a dynamic random environment, together with a nearest-neighbor random walk that on occupied sites has a local drift to the right but on vacant sites has a local drift to the left. In previous work we
International Nuclear Information System (INIS)
Ramond, P.
1993-01-01
The Wolfenstein parametrization is extended to the quark masses in the deep ultraviolet, and an algorithm to derive symmetric textures which are compatible with existing data is developed. It is found that there are only five such textures
Directory of Open Access Journals (Sweden)
Camille Roussel
2018-05-01
Full Text Available Red blood cells (RBC ability to circulate is closely related to their surface area-to-volume ratio. A decrease in this ratio induces a decrease in RBC deformability that can lead to their retention and elimination in the spleen. We recently showed that a subpopulation of “small RBC” with reduced projected surface area accumulated upon storage in blood bank concentrates, but data on the volume of these altered RBC are lacking. So far, single cell measurement of RBC volume has remained a challenging task achieved by a few sophisticated methods some being subject to potential artifacts. We aimed to develop a reproducible and ergonomic method to assess simultaneously RBC volume and morphology at the single cell level. We adapted the fluorescence exclusion measurement of volume in nucleated cells to the measurement of RBC volume. This method requires no pre-treatment of the cell and can be performed in physiological or experimental buffer. In addition to RBC volume assessment, brightfield images enabling a precise definition of the morphology and the measurement of projected surface area can be generated simultaneously. We first verified that fluorescence exclusion is precise, reproducible and can quantify volume modifications following morphological changes induced by heating or incubation in non-physiological medium. We then used the method to characterize RBC stored for 42 days in SAG-M in blood bank conditions. Simultaneous determination of the volume, projected surface area and morphology allowed to evaluate the surface area-to-volume ratio of individual RBC upon storage. We observed a similar surface area-to-volume ratio in discocytes (D and echinocytes I (EI, which decreased in EII (7% and EIII (24%, sphero-echinocytes (SE; 41% and spherocytes (S; 47%. If RBC dimensions determine indeed the ability of RBC to cross the spleen, these modifications are expected to induce the rapid splenic entrapment of the most morphologically altered RBC
Directory of Open Access Journals (Sweden)
Nelson Pires
2016-07-01
Full Text Available A conceptually simple formulation is proposed for a new empirical sea state bias (SSB model using information retrieved entirely from altimetric data. Nonparametric regression techniques are used, based on penalized smoothing splines adjusted to each predictor and then combined by a Generalized Additive Model. In addition to the significant wave height (SWH and wind speed (U10, a mediator parameter designed by the mean wave period derived from radar altimetry, has proven to improve the model performance in explaining some of the SSB variability, especially in swell ocean regions with medium-high SWH and low U10. A collinear analysis of scaled sea level anomalies (SLA variance differences shows conformity between the proposed model and the established SSB models. The new formulation aims to be a fast, reliable and flexible SSB model, in line with the well-settled SSB corrections, depending exclusively on altimetric information. The suggested method is computationally efficient and capable of generating a stable model with a small training dataset, a useful feature for forthcoming missions.
Holographic Spherically Symmetric Metrics
Petri, Michael
The holographic principle (HP) conjectures, that the maximum number of degrees of freedom of any realistic physical system is proportional to the system's boundary area. The HP has its roots in the study of black holes. It has recently been applied to cosmological solutions. In this article we apply the HP to spherically symmetric static space-times. We find that any regular spherically symmetric object saturating the HP is subject to tight constraints on the (interior) metric, energy-density, temperature and entropy-density. Whenever gravity can be described by a metric theory, gravity is macroscopically scale invariant and the laws of thermodynamics hold locally and globally, the (interior) metric of a regular holographic object is uniquely determined up to a constant factor and the interior matter-state must follow well defined scaling relations. When the metric theory of gravity is general relativity, the interior matter has an overall string equation of state (EOS) and a unique total energy-density. Thus the holographic metric derived in this article can serve as simple interior 4D realization of Mathur's string fuzzball proposal. Some properties of the holographic metric and its possible experimental verification are discussed. The geodesics of the holographic metric describe an isotropically expanding (or contracting) universe with a nearly homogeneous matter-distribution within the local Hubble volume. Due to the overall string EOS the active gravitational mass-density is zero, resulting in a coasting expansion with Ht = 1, which is compatible with the recent GRB-data.
Jiang, Haiyong
2016-04-11
We present an automatic algorithm for symmetrizing facade layouts. Our method symmetrizes a given facade layout while minimally modifying the original layout. Based on the principles of symmetry in urban design, we formulate the problem of facade layout symmetrization as an optimization problem. Our system further enhances the regularity of the final layout by redistributing and aligning boxes in the layout. We demonstrate that the proposed solution can generate symmetric facade layouts efficiently. © 2015 IEEE.
Symmetrization of Facade Layouts
Jiang, Haiyong; Yan, Dong-Ming; Dong, Weiming; Wu, Fuzhang; Nan, Liangliang; Zhang, Xiaopeng
2016-01-01
We present an automatic approach for symmetrizing urban facade layouts. Our method can generate a symmetric layout through minimally modifying the original input layout. Based on the principles of symmetry in urban design, we formulate facade layout symmetrization as an optimization problem. Our method further enhances the regularity of the final layout by redistributing and aligning elements in the layout. We demonstrate that the proposed solution can effectively generate symmetric facade layouts.
Jiang, Haiyong; Dong, Weiming; Yan, Dongming; Zhang, Xiaopeng
2016-01-01
We present an automatic algorithm for symmetrizing facade layouts. Our method symmetrizes a given facade layout while minimally modifying the original layout. Based on the principles of symmetry in urban design, we formulate the problem of facade layout symmetrization as an optimization problem. Our system further enhances the regularity of the final layout by redistributing and aligning boxes in the layout. We demonstrate that the proposed solution can generate symmetric facade layouts efficiently. © 2015 IEEE.
Symmetrization of Facade Layouts
Jiang, Haiyong
2016-02-26
We present an automatic approach for symmetrizing urban facade layouts. Our method can generate a symmetric layout through minimally modifying the original input layout. Based on the principles of symmetry in urban design, we formulate facade layout symmetrization as an optimization problem. Our method further enhances the regularity of the final layout by redistributing and aligning elements in the layout. We demonstrate that the proposed solution can effectively generate symmetric facade layouts.
The Symmetric Rudin-Shapiro Transform
DEFF Research Database (Denmark)
Harbo, Anders La-Cour
2003-01-01
A method for constructing spread spectrum sequences is presented. The method is based on a linear, orthogonal, and symmetric transform given as the Rudin-Shapiro transform (RST), which is in many respects quite similar to the Haar wavelet packet transform. The RST provides the means for generatin...... large sets of spread spectrum signals. This presentation provides a simple definition of the symmetric RST that leads to a fast N log(N) and numerically stable implementation of the transform....
The Symmetric Rudin-Shapiro Transform
DEFF Research Database (Denmark)
Harbo, Anders La-Cour
2003-01-01
A method for constructing spread spectrum sequences is presented. The method is based on a linear, orthogonal, symmetric transform, the Rudin-Shapiro transform (RST), which is in many respects quite similar to the Haar wavelet packet transform. The RST provides the means for generating large sets...... of spread spectrum signals. This presentation provides a simple definition of the symmetric RST that leads to a fast N log(N) and numerically stable implementation of the transform....
Golden, Ryan; Cho, Ilwoo
2015-01-01
In this paper, we study structure theorems of algebras of symmetric functions. Based on a certain relation on elementary symmetric polynomials generating such algebras, we consider perturbation in the algebras. In particular, we understand generators of the algebras as perturbations. From such perturbations, define injective maps on generators, which induce algebra-monomorphisms (or embeddings) on the algebras. They provide inductive structure theorems on algebras of symmetric polynomials. As...
Symmetric cryptographic protocols
Ramkumar, Mahalingam
2014-01-01
This book focuses on protocols and constructions that make good use of symmetric pseudo random functions (PRF) like block ciphers and hash functions - the building blocks for symmetric cryptography. Readers will benefit from detailed discussion of several strategies for utilizing symmetric PRFs. Coverage includes various key distribution strategies for unicast, broadcast and multicast security, and strategies for constructing efficient digests of dynamic databases using binary hash trees. • Provides detailed coverage of symmetric key protocols • Describes various applications of symmetric building blocks • Includes strategies for constructing compact and efficient digests of dynamic databases
Centrioles in Symmetric Spaces
Quast, Peter
2011-01-01
We describe all centrioles in irreducible simply connected pointed symmetric spaces of compact type in terms of the root system of the ambient space, and we study some geometric properties of centrioles.
A symmetrical rail accelerator
International Nuclear Information System (INIS)
Igenbergs, E.
1991-01-01
This paper reports on the symmetrical rail accelerator that has four rails, which are arranged symmetrically around the bore. The opposite rails have the same polarity and the adjacent rails the opposite polarity. In this configuration the radial force acting upon the individual rails is significantly smaller than in a conventional 2-rail configuration and a plasma armature is focussed towards the axis of the barrel. Experimental results indicate a higher efficiency compared to a conventional rail accelerator
International Nuclear Information System (INIS)
Matsuki, Takayuki
1976-01-01
Symmetric eikonal expansion for the scattering amplitude is formulated for nonrelativistic and relativistic potential scatterings and also for the quantum field theory. The first approximations coincide with those of Levy and Sucher. The obtained scattering amplitudes are time reversal invariant for all cases and are crossing symmetric for the quantum field theory in each order of approximation. The improved eikonal phase introduced by Levy and Sucher is also derived from the different approximation scheme from the above. (auth.)
Implementation of mutual exclusion in VHDL
Boersma, M.V.; Benders, L.P.M.; Stevens, M.P.J.; Wilsey, P.A.; Rhodes, D.
1994-01-01
In VHDL it is difficult to implement mutual exclusion at an abstract level since atomic actions are required. A local status model and an arbiter model are presented to achieve mutual exclusion in VHDL. Shared data, protected by a mutual exclusion mechanism, cannot be modelled as a simple, resolved
Symmetric configurations highlighted by collective quantum coherence
Energy Technology Data Exchange (ETDEWEB)
Obster, Dennis [Radboud University, Institute for Mathematics, Astrophysics and Particle Physics, Nijmegen (Netherlands); Kyoto University, Yukawa Institute for Theoretical Physics, Kyoto (Japan); Sasakura, Naoki [Kyoto University, Yukawa Institute for Theoretical Physics, Kyoto (Japan)
2017-11-15
Recent developments in quantum gravity have shown the Lorentzian treatment to be a fruitful approach towards the emergence of macroscopic space-times. In this paper, we discuss another related aspect of the Lorentzian treatment: we argue that collective quantum coherence may provide a simple mechanism for highlighting symmetric configurations over generic non-symmetric ones. After presenting the general framework of the mechanism, we show the phenomenon in some concrete simple examples in the randomly connected tensor network, which is tightly related to a certain model of quantum gravity, i.e., the canonical tensor model. We find large peaks at configurations invariant under Lie-group symmetries as well as a preference for charge quantization, even in the Abelian case. In future study, this simple mechanism may provide a way to analyze the emergence of macroscopic space-times with global symmetries as well as various other symmetries existing in nature, which are usually postulated. (orig.)
Multiparty symmetric sum types
DEFF Research Database (Denmark)
Nielsen, Lasse; Yoshida, Nobuko; Honda, Kohei
2010-01-01
This paper introduces a new theory of multiparty session types based on symmetric sum types, by which we can type non-deterministic orchestration choice behaviours. While the original branching type in session types can represent a choice made by a single participant and accepted by others...... determining how the session proceeds, the symmetric sum type represents a choice made by agreement among all the participants of a session. Such behaviour can be found in many practical systems, including collaborative workflow in healthcare systems for clinical practice guidelines (CPGs). Processes...... with the symmetric sums can be embedded into the original branching types using conductor processes. We show that this type-driven embedding preserves typability, satisfies semantic soundness and completeness, and meets the encodability criteria adapted to the typed setting. The theory leads to an efficient...
Counting with symmetric functions
Mendes, Anthony
2015-01-01
This monograph provides a self-contained introduction to symmetric functions and their use in enumerative combinatorics. It is the first book to explore many of the methods and results that the authors present. Numerous exercises are included throughout, along with full solutions, to illustrate concepts and also highlight many interesting mathematical ideas. The text begins by introducing fundamental combinatorial objects such as permutations and integer partitions, as well as generating functions. Symmetric functions are considered in the next chapter, with a unique emphasis on the combinatorics of the transition matrices between bases of symmetric functions. Chapter 3 uses this introductory material to describe how to find an assortment of generating functions for permutation statistics, and then these techniques are extended to find generating functions for a variety of objects in Chapter 4. The next two chapters present the Robinson-Schensted-Knuth algorithm and a method for proving Pólya’s enu...
Symmetric Tensor Decomposition
DEFF Research Database (Denmark)
Brachat, Jerome; Comon, Pierre; Mourrain, Bernard
2010-01-01
We present an algorithm for decomposing a symmetric tensor, of dimension n and order d, as a sum of rank-1 symmetric tensors, extending the algorithm of Sylvester devised in 1886 for binary forms. We recall the correspondence between the decomposition of a homogeneous polynomial in n variables...... of polynomial equations of small degree in non-generic cases. We propose a new algorithm for symmetric tensor decomposition, based on this characterization and on linear algebra computations with Hankel matrices. The impact of this contribution is two-fold. First it permits an efficient computation...... of the decomposition of any tensor of sub-generic rank, as opposed to widely used iterative algorithms with unproved global convergence (e.g. Alternate Least Squares or gradient descents). Second, it gives tools for understanding uniqueness conditions and for detecting the rank....
Revisiting the Optical PT-Symmetric Dimer
Directory of Open Access Journals (Sweden)
José Delfino Huerta Morales
2016-08-01
Full Text Available Optics has proved a fertile ground for the experimental simulation of quantum mechanics. Most recently, optical realizations of PT -symmetric quantum mechanics have been shown, both theoretically and experimentally, opening the door to international efforts aiming at the design of practical optical devices exploiting this symmetry. Here, we focus on the optical PT -symmetric dimer, a two-waveguide coupler where the materials show symmetric effective gain and loss, and provide a review of the linear and nonlinear optical realizations from a symmetry-based point of view. We go beyond a simple review of the literature and show that the dimer is just the smallest of a class of planar N-waveguide couplers that are the optical realization of the Lorentz group in 2 + 1 dimensions. Furthermore, we provide a formulation to describe light propagation through waveguide couplers described by non-Hermitian mode coupling matrices based on a non-Hermitian generalization of the Ehrenfest theorem.
Distributed Searchable Symmetric Encryption
Bösch, C.T.; Peter, Andreas; Leenders, Bram; Lim, Hoon Wei; Tang, Qiang; Wang, Huaxiong; Hartel, Pieter H.; Jonker, Willem
Searchable Symmetric Encryption (SSE) allows a client to store encrypted data on a storage provider in such a way, that the client is able to search and retrieve the data selectively without the storage provider learning the contents of the data or the words being searched for. Practical SSE schemes
Chen, Yan; Feng, Huijuan; Ma, Jiayao; Peng, Rui; You, Zhong
2016-06-01
The traditional waterbomb origami, produced from a pattern consisting of a series of vertices where six creases meet, is one of the most widely used origami patterns. From a rigid origami viewpoint, it generally has multiple degrees of freedom, but when the pattern is folded symmetrically, the mobility reduces to one. This paper presents a thorough kinematic investigation on symmetric folding of the waterbomb pattern. It has been found that the pattern can have two folding paths under certain circumstance. Moreover, the pattern can be used to fold thick panels. Not only do the additional constraints imposed to fold the thick panels lead to single degree of freedom folding, but the folding process is also kinematically equivalent to the origami of zero-thickness sheets. The findings pave the way for the pattern being readily used to fold deployable structures ranging from flat roofs to large solar panels.
Rome, J.A.; Harris, J.H.
1984-01-01
A fusion reactor device is provided in which the magnetic fields for plasma confinement in a toroidal configuration is produced by a plurality of symmetrical modular coils arranged to form a symmetric modular torsatron referred to as a symmotron. Each of the identical modular coils is helically deformed and comprise one field period of the torsatron. Helical segments of each coil are connected by means of toroidally directed windbacks which may also provide part of the vertical field required for positioning the plasma. The stray fields of the windback segments may be compensated by toroidal coils. A variety of magnetic confinement flux surface configurations may be produced by proper modulation of the winding pitch of the helical segments of the coils, as in a conventional torsatron, winding the helix on a noncircular cross section and varying the poloidal and radial location of the windbacks and the compensating toroidal ring coils.
Spherically symmetric charged compact stars
Energy Technology Data Exchange (ETDEWEB)
Maurya, S.K. [University of Nizwa, Department of Mathematical and Physical Sciences, College of Arts and Science, Nizwa (Oman); Gupta, Y.K. [Jaypee Institute of Information Technology University, Department of Mathematics, Noida, Uttar Pradesh (India); Ray, Saibal [Government College of Engineering and Ceramic Technology, Department of Physics, Kolkata, West Bengal (India); Chowdhury, Sourav Roy [Seth Anandaram Jaipuria College, Department of Physics, Kolkata, West Bengal (India)
2015-08-15
In this article we consider the static spherically symmetric metric of embedding class 1. When solving the Einstein-Maxwell field equations we take into account the presence of ordinary baryonic matter together with the electric charge. Specific new charged stellar models are obtained where the solutions are entirely dependent on the electromagnetic field, such that the physical parameters, like density, pressure etc. do vanish for the vanishing charge. We systematically analyze altogether the three sets of Solutions I, II, and III of the stellar models for a suitable functional relation of ν(r). However, it is observed that only the Solution I provides a physically valid and well-behaved situation, whereas the Solutions II and III are not well behaved and hence not included in the study. Thereafter it is exclusively shown that the Solution I can pass through several standard physical tests performed by us. To validate the solution set presented here a comparison has also been made with that of the compact stars, like RX J 1856 - 37, Her X - 1, PSR 1937+21, PSRJ 1614-2230, and PSRJ 0348+0432, and we have shown the feasibility of the models. (orig.)
Symmetric vectors and algebraic classification
International Nuclear Information System (INIS)
Leibowitz, E.
1980-01-01
The concept of symmetric vector field in Riemannian manifolds, which arises in the study of relativistic cosmological models, is analyzed. Symmetric vectors are tied up with the algebraic properties of the manifold curvature. A procedure for generating a congruence of symmetric fields out of a given pair is outlined. The case of a three-dimensional manifold of constant curvature (''isotropic universe'') is studied in detail, with all its symmetric vector fields being explicitly constructed
Representations of locally symmetric spaces
International Nuclear Information System (INIS)
Rahman, M.S.
1995-09-01
Locally symmetric spaces in reference to globally and Hermitian symmetric Riemannian spaces are studied. Some relations between locally and globally symmetric spaces are exhibited. A lucid account of results on relevant spaces, motivated by fundamental problems, are formulated as theorems and propositions. (author). 10 refs
Filtering microfluidic bubble trains at a symmetric junction.
Parthiban, Pravien; Khan, Saif A
2012-02-07
We report how a nominally symmetric microfluidic junction can be used to sort all bubbles of an incoming train exclusively into one of its arms. The existence of this "filter" regime is unexpected, given that the junction is symmetric. We analyze this behavior by quantifying how bubbles modulate the hydrodynamic resistance in microchannels and show how speeding up a bubble train whilst preserving its spatial periodicity can lead to filtering at a nominally symmetric junction. We further show how such an asymmetric traffic of bubble trains can be triggered in symmetric geometries by identifying conditions wherein the resistance to flow decreases with an increase in the number of bubbles in the microchannel and derive an exact criterion to predict the same.
Symmetric extendibility of quantum states
Nowakowski, Marcin L.
2015-01-01
Studies on symmetric extendibility of quantum states become especially important in a context of analysis of one-way quantum measures of entanglement, distilabillity and security of quantum protocols. In this paper we analyse composite systems containing a symmetric extendible part with a particular attention devoted to one-way security of such systems. Further, we introduce a new one-way monotone based on the best symmetric approximation of quantum state. We underpin those results with geome...
International Nuclear Information System (INIS)
Burtraw, Dallas; Palmer, Karen; Kahn, Danny
2010-01-01
How to set policy in the presence of uncertainty has been central in debates over climate policy. Concern about costs has motivated the proposal for a cap-and-trade program for carbon dioxide, with a 'safety valve' that would mitigate against spikes in the cost of emission reductions by introducing additional emission allowances into the market when marginal costs rise above the specified allowance price level. We find two significant problems, both stemming from the asymmetry of an instrument that mitigates only against a price increase. One is that most important examples of price volatility in cap-and-trade programs have occurred not when prices spiked, but instead when allowance prices collapsed. Second, a single-sided safety valve may have unintended consequences for investment. We illustrate that a symmetric safety valve provides environmental and welfare improvements relative to the conventional one-sided approach.
Exact axially symmetric galactic dynamos
Henriksen, R. N.; Woodfinden, A.; Irwin, J. A.
2018-05-01
We give a selection of exact dynamos in axial symmetry on a galactic scale. These include some steady examples, at least one of which is wholly analytic in terms of simple functions and has been discussed elsewhere. Most solutions are found in terms of special functions, such as associated Lagrange or hypergeometric functions. They may be considered exact in the sense that they are known to any desired accuracy in principle. The new aspect developed here is to present scale-invariant solutions with zero resistivity that are self-similar in time. The time dependence is either a power law or an exponential factor, but since the geometry of the solution is self-similar in time we do not need to fix a time to study it. Several examples are discussed. Our results demonstrate (without the need to invoke any other mechanisms) X-shaped magnetic fields and (axially symmetric) magnetic spiral arms (both of which are well observed and documented) and predict reversing rotation measures in galaxy haloes (now observed in the CHANG-ES sample) as well as the fact that planar magnetic spirals are lifted into the galactic halo.
Directory of Open Access Journals (Sweden)
Giuseppe Dattoli
1996-05-01
Full Text Available q analog of bessel functions, symmetric under the interchange of q and q^ −1 are introduced. The definition is based on the generating function realized as product of symmetric q-exponential functions with appropriate arguments. Symmetric q-Bessel function are shown to satisfy various identities as well as second-order q-differential equations, which in the limit q → 1 reproduce those obeyed by the usual cylindrical Bessel functions. A brief discussion on the possible algebraic setting for symmetric q-Bessel functions is also provided.
Integrable dissipative exclusion process: Correlation functions and physical properties
Crampe, N.; Ragoucy, E.; Rittenberg, V.; Vanicat, M.
2016-09-01
We study a one-parameter generalization of the symmetric simple exclusion process on a one-dimensional lattice. In addition to the usual dynamics (where particles can hop with equal rates to the left or to the right with an exclusion constraint), annihilation and creation of pairs can occur. The system is driven out of equilibrium by two reservoirs at the boundaries. In this setting the model is still integrable: it is related to the open XXZ spin chain through a gauge transformation. This allows us to compute the full spectrum of the Markov matrix using Bethe equations. We also show that the stationary state can be expressed in a matrix product form permitting to compute the multipoints correlation functions as well as the mean value of the lattice and the creation-annihilation currents. Finally, the variance of the lattice current is computed for a finite-size system. In the thermodynamic limit, it matches the value obtained from the associated macroscopic fluctuation theory.
Conformally symmetric traversable wormholes
International Nuclear Information System (INIS)
Boehmer, Christian G.; Harko, Tiberiu; Lobo, Francisco S. N.
2007-01-01
Exact solutions of traversable wormholes are found under the assumption of spherical symmetry and the existence of a nonstatic conformal symmetry, which presents a more systematic approach in searching for exact wormhole solutions. In this work, a wide variety of solutions are deduced by considering choices for the form function, a specific linear equation of state relating the energy density and the pressure anisotropy, and various phantom wormhole geometries are explored. A large class of solutions impose that the spatial distribution of the exotic matter is restricted to the throat neighborhood, with a cutoff of the stress-energy tensor at a finite junction interface, although asymptotically flat exact solutions are also found. Using the 'volume integral quantifier', it is found that the conformally symmetric phantom wormhole geometries may, in principle, be constructed by infinitesimally small amounts of averaged null energy condition violating matter. Considering the tidal acceleration traversability conditions for the phantom wormhole geometry, specific wormhole dimensions and the traversal velocity are also deduced
Spherically symmetric self-similar universe
Energy Technology Data Exchange (ETDEWEB)
Dyer, C C [Toronto Univ., Ontario (Canada)
1979-10-01
A spherically symmetric self-similar dust-filled universe is considered as a simple model of a hierarchical universe. Observable differences between the model in parabolic expansion and the corresponding homogeneous Einstein-de Sitter model are considered in detail. It is found that an observer at the centre of the distribution has a maximum observable redshift and can in principle see arbitrarily large blueshifts. It is found to yield an observed density-distance law different from that suggested by the observations of de Vaucouleurs. The use of these solutions as central objects for Swiss-cheese vacuoles is discussed.
Geometrodynamics of spherically symmetric Lovelock gravity
International Nuclear Information System (INIS)
Kunstatter, Gabor; Taves, Tim; Maeda, Hideki
2012-01-01
We derive the Hamiltonian for spherically symmetric Lovelock gravity using the geometrodynamics approach pioneered by Kuchar (1994 Phys. Rev. D 50 3961) in the context of four-dimensional general relativity. When written in terms of the areal radius, the generalized Misner-Sharp mass and their conjugate momenta, the generic Lovelock action and Hamiltonian take on precisely the same simple forms as in general relativity. This result supports the interpretation of Lovelock gravity as the natural higher dimensional extension of general relativity. It also provides an important first step towards the study of the quantum mechanics, Hamiltonian thermodynamics and formation of generic Lovelock black holes. (fast track communication)
Mesotherapy for benign symmetric lipomatosis.
Hasegawa, Toshio; Matsukura, Tomoyuki; Ikeda, Shigaku
2010-04-01
Benign symmetric lipomatosis, also known as Madelung disease, is a rare disorder characterized by fat distribution around the shoulders, arms, and neck in the context of chronic alcoholism. Complete excision of nonencapsulated lipomas is difficult. However, reports describing conservative therapeutic measures for lipomatosis are rare. The authors present the case of a 42-year-old man with a diagnosis of benign symmetric lipomatosis who had multiple, large, symmetrical masses in his neck. Multiple phosphatidylcholine injections in the neck were administered 4 weeks apart, a total of seven times to achieve lipolysis. The patient's lipomatosis improved in response to the injections, and he achieved good cosmetic results. Intralesional injection, termed mesotherapy, using phosphatidylcholine is a potentially effective therapy for benign symmetric lipomatosis that should be reconsidered as a therapeutic option for this disease.
Looking for symmetric Bell inequalities
Bancal, Jean-Daniel; Gisin, Nicolas; Pironio, Stefano
2010-01-01
Finding all Bell inequalities for a given number of parties, measurement settings and measurement outcomes is in general a computationally hard task. We show that all Bell inequalities which are symmetric under the exchange of parties can be found by examining a symmetrized polytope which is simpler than the full Bell polytope. As an illustration of our method, we generate 238 885 new Bell inequalities and 1085 new Svetlichny inequalities. We find, in particular, facet inequalities for Bell e...
On Split Lie Algebras with Symmetric Root Systems
Indian Academy of Sciences (India)
... and any I j a well described ideal of , satisfying [ I j , I k ] = 0 if j ≠ k . Under certain conditions, the simplicity of is characterized and it is shown that is the direct sum of the family of its minimal ideals, each one being a simple split Lie algebra with a symmetric root system and having all its nonzero roots connected.
On split Lie algebras with symmetric root systems
Indian Academy of Sciences (India)
ideal of L, satisfying [Ij ,Ik] = 0 if j = k. Under certain conditions, the simplicity of L is characterized and it is shown that L is the direct sum of the family of its minimal ideals, each one being a simple split Lie algebra with a symmetric root system and having all its nonzero roots connected. Keywords. Infinite dimensional Lie ...
Energy Technology Data Exchange (ETDEWEB)
Kugler, W.
2007-01-15
Hard exclusive processes in high energy electron proton scattering offer the opportunity to get access to a new generation of parton distributions, the so-called generalized parton distributions (GPDs). This functions provide more detailed informations about the structure of the nucleon than the usual PDFs obtained from DIS. In this work we present a detailed analysis of exclusive processes, especially of hard exclusive meson production. We investigated the influence of exclusive produced mesons on the semi-inclusive production of mesons at fixed target experiments like HERMES. Further we give a detailed analysis of higher order corrections (NLO) for the exclusive production of mesons in a very broad range of kinematics. (orig.)
Droplet Traffic Control at a simple T junction
Panizza, Pascal; Engl, Wilfried; Colin, Annie; Ajdari, Armand
2006-03-01
A basic yet essential element of every traffic flow control is the effect of a junction where the flow is separated into several streams. How do pedestrians, vehicles or blood cells divide when they reach a junction? How does the outcome depend on their density? Similar fundamental questions hold for much simpler systems: in this paper, we have studied the behaviour of periodic trains of water droplets flowing in oil through a channel as they reach a simple, locally symmetric, T junction. Depending on their dilution, we observe that the droplets are either alternately partitioned between both outlets or sorted exclusively into the shortest one. We show that this surprising behaviour results from the hydrodynamic feed-back of drops in the two outlets on the selection process occurring at the junction. Our results offer a first guide for the design and modelling of droplet traffic in complex branched networks, a necessary step towards parallelized droplet-based ``lab-on-chip'' devices.
Harmonic analysis on symmetric spaces
Terras, Audrey
This text explores the geometry and analysis of higher rank analogues of the symmetric spaces introduced in volume one. To illuminate both the parallels and differences of the higher rank theory, the space of positive matrices is treated in a manner mirroring that of the upper-half space in volume one. This concrete example furnishes motivation for the general theory of noncompact symmetric spaces, which is outlined in the final chapter. The book emphasizes motivation and comprehensibility, concrete examples and explicit computations (by pen and paper, and by computer), history, and, above all, applications in mathematics, statistics, physics, and engineering. The second edition includes new sections on Donald St. P. Richards’s central limit theorem for O(n)-invariant random variables on the symmetric space of GL(n, R), on random matrix theory, and on advances in the theory of automorphic forms on arithmetic groups.
Looking for symmetric Bell inequalities
International Nuclear Information System (INIS)
Bancal, Jean-Daniel; Gisin, Nicolas; Pironio, Stefano
2010-01-01
Finding all Bell inequalities for a given number of parties, measurement settings and measurement outcomes is in general a computationally hard task. We show that all Bell inequalities which are symmetric under the exchange of parties can be found by examining a symmetrized polytope which is simpler than the full Bell polytope. As an illustration of our method, we generate 238 885 new Bell inequalities and 1085 new Svetlichny inequalities. We find, in particular, facet inequalities for Bell experiments involving two parties and two measurement settings that are not of the Collins-Gisin-Linden-Massar-Popescu type.
Symmetric normalisation for intuitionistic logic
DEFF Research Database (Denmark)
Guenot, Nicolas; Straßburger, Lutz
2014-01-01
We present two proof systems for implication-only intuitionistic logic in the calculus of structures. The first is a direct adaptation of the standard sequent calculus to the deep inference setting, and we describe a procedure for cut elimination, similar to the one from the sequent calculus......, but using a non-local rewriting. The second system is the symmetric completion of the first, as normally given in deep inference for logics with a DeMorgan duality: all inference rules have duals, as cut is dual to the identity axiom. We prove a generalisation of cut elimination, that we call symmetric...
Diagrams for symmetric product orbifolds
International Nuclear Information System (INIS)
Pakman, Ari; Rastelli, Leonardo; Razamat, Shlomo S.
2009-01-01
We develop a diagrammatic language for symmetric product orbifolds of two-dimensional conformal field theories. Correlation functions of twist operators are written as sums of diagrams: each diagram corresponds to a branched covering map from a surface where the fields are single-valued to the base sphere where twist operators are inserted. This diagrammatic language facilitates the study of the large N limit and makes more transparent the analogy between symmetric product orbifolds and free non-abelian gauge theories. We give a general algorithm to calculate the leading large N contribution to four-point correlators of twist fields.
Looking for symmetric Bell inequalities
Energy Technology Data Exchange (ETDEWEB)
Bancal, Jean-Daniel; Gisin, Nicolas [Group of Applied Physics, University of Geneva, 20 rue de l' Ecole-de Medecine, CH-1211 Geneva 4 (Switzerland); Pironio, Stefano, E-mail: jean-daniel.bancal@unige.c [Laboratoire d' Information Quantique, Universite Libre de Bruxelles (Belgium)
2010-09-24
Finding all Bell inequalities for a given number of parties, measurement settings and measurement outcomes is in general a computationally hard task. We show that all Bell inequalities which are symmetric under the exchange of parties can be found by examining a symmetrized polytope which is simpler than the full Bell polytope. As an illustration of our method, we generate 238 885 new Bell inequalities and 1085 new Svetlichny inequalities. We find, in particular, facet inequalities for Bell experiments involving two parties and two measurement settings that are not of the Collins-Gisin-Linden-Massar-Popescu type.
Symmetric autocompensating quantum key distribution
Walton, Zachary D.; Sergienko, Alexander V.; Levitin, Lev B.; Saleh, Bahaa E. A.; Teich, Malvin C.
2004-08-01
We present quantum key distribution schemes which are autocompensating (require no alignment) and symmetric (Alice and Bob receive photons from a central source) for both polarization and time-bin qubits. The primary benefit of the symmetric configuration is that both Alice and Bob may have passive setups (neither Alice nor Bob is required to make active changes for each run of the protocol). We show that both the polarization and the time-bin schemes may be implemented with existing technology. The new schemes are related to previously described schemes by the concept of advanced waves.
João Leão
2008-01-01
This paper examines the use of exclusive dealing agreements to prevent the entry of rival firms. An exclusive dealing agreement is a contract between a buyer and a seller where the buyer commits to buy a good exclusively from the seller. One main concern of the literature is to explain how an incumbent seller is able to persuade the buyers to sign an exclusive dealing agreement that deters the entry of a more efficient rival seller. We propose a new explanation when the buyers are downstream ...
Krein signature for instability of PT-symmetric states
Chernyavsky, Alexander; Pelinovsky, Dmitry E.
2018-05-01
Krein quantity is introduced for isolated neutrally stable eigenvalues associated with the stationary states in the PT-symmetric nonlinear Schrödinger equation. Krein quantity is real and nonzero for simple eigenvalues but it vanishes if two simple eigenvalues coalesce into a defective eigenvalue. A necessary condition for bifurcation of unstable eigenvalues from the defective eigenvalue is proved. This condition requires the two simple eigenvalues before the coalescence point to have opposite Krein signatures. The theory is illustrated with several numerical examples motivated by recent publications in physics literature.
Symmetric relations of finite negativity
Kaltenbaeck, M.; Winkler, H.; Woracek, H.; Forster, KH; Jonas, P; Langer, H
2006-01-01
We construct and investigate a space which is related to a symmetric linear relation S of finite negativity on an almost Pontryagin space. This space is the indefinite generalization of the completion of dom S with respect to (S.,.) for a strictly positive S on a Hilbert space.
Tilting-connected symmetric algebras
Aihara, Takuma
2010-01-01
The notion of silting mutation was introduced by Iyama and the author. In this paper we mainly study silting mutation for self-injective algebras and prove that any representation-finite symmetric algebra is tilting-connected. Moreover we give some sufficient conditions for a Bongartz-type Lemma to hold for silting objects.
Symmetric group representations and Z
Adve, Anshul; Yong, Alexander
2017-01-01
We discuss implications of the following statement about the representation theory of symmetric groups: every integer appears infinitely often as an irreducible character evaluation, and every nonnegative integer appears infinitely often as a Littlewood-Richardson coefficient and as a Kronecker coefficient.
Symmetric Key Authentication Services Revisited
Crispo, B.; Popescu, B.C.; Tanenbaum, A.S.
2004-01-01
Most of the symmetric key authentication schemes deployed today are based on principles introduced by Needham and Schroeder [15] more than twenty years ago. However, since then, the computing environment has evolved from a LAN-based client-server world to include new paradigms, including wide area
Quantum systems and symmetric spaces
International Nuclear Information System (INIS)
Olshanetsky, M.A.; Perelomov, A.M.
1978-01-01
Certain class of quantum systems with Hamiltonians related to invariant operators on symmetric spaces has been investigated. A number of physical facts have been derived as a consequence. In the classical limit completely integrable systems related to root systems are obtained
The symmetric longest queue system
van Houtum, Geert-Jan; Adan, Ivo; van der Wal, Jan
1997-01-01
We derive the performance of the exponential symmetric longest queue system from two variants: a longest queue system with Threshold Rejection of jobs and one with Threshold Addition of jobs. It is shown that these two systems provide lower and upper bounds for the performance of the longest queue
Strong orientational coordinates and orientational order parameters for symmetric objects
International Nuclear Information System (INIS)
Haji-Akbari, Amir; Glotzer, Sharon C
2015-01-01
Recent advancements in the synthesis of anisotropic macromolecules and nanoparticles have spurred an immense interest in theoretical and computational studies of self-assembly. The cornerstone of such studies is the role of shape in self-assembly and in inducing complex order. The problem of identifying different types of order that can emerge in such systems can, however, be challenging. Here, we revisit the problem of quantifying orientational order in systems of building blocks with non-trivial rotational symmetries. We first propose a systematic way of constructing orientational coordinates for such symmetric building blocks. We call the arising tensorial coordinates strong orientational coordinates (SOCs) as they fully and exclusively specify the orientation of a symmetric object. We then use SOCs to describe and quantify local and global orientational order, and spatiotemporal orientational correlations in systems of symmetric building blocks. The SOCs and the orientational order parameters developed in this work are not only useful in performing and analyzing computer simulations of symmetric molecules or particles, but can also be utilized for the efficient storage of rotational information in long trajectories of evolving many-body systems. (paper)
Symmetric imaging findings in neuroradiology
International Nuclear Information System (INIS)
Zlatareva, D.
2015-01-01
Full text: Learning objectives: to make a list of diseases and syndromes which manifest as bilateral symmetric findings on computed tomography and magnetic resonance imaging; to discuss the clinical and radiological differential diagnosis for these diseases; to explain which of these conditions necessitates urgent therapy and when additional studies and laboratory can precise diagnosis. There is symmetry in human body and quite often we compare the affected side to the normal one but in neuroradiology we might have bilateral findings which affected pair structures or corresponding anatomic areas. It is very rare when clinical data prompt diagnosis. Usually clinicians suspect such an involvement but Ct and MRI can reveal symmetric changes and are one of the leading diagnostic tool. The most common location of bilateral findings is basal ganglia and thalamus. There are a number of diseases affecting these structures symmetrically: metabolic and systemic diseases, intoxication, neurodegeneration and vascular conditions, toxoplasmosis, tumors and some infections. Malformations of cortical development and especially bilateral perisylvian polymicrogyria requires not only exact report on the most affected parts but in some cases genetic tests or combination with other clinical symptoms. In the case of herpes simplex encephalitis bilateral temporal involvement is common and this finding very often prompt therapy even before laboratory results. Posterior reversible encephalopathy syndrome (PReS) and some forms of hypoxic ischemic encephalopathy can lead to symmetric changes. In these acute conditions MR plays a crucial role not only in diagnosis but also in monitoring of the therapeutic effect. Patients with neurofibromatosis type 1 or type 2 can demonstrate bilateral optic glioma combined with spinal neurofibroma and bilateral acoustic schwanoma respectively. Mirror-image aneurysm affecting both internal carotid or middle cerebral arteries is an example of symmetry in
Definition of Exclusion Zones Using Seismic Data
Bartal, Y.; Villagran, M.; Ben Horin, Y.; Leonard, G.; Joswig, M.
- In verifying compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT), there is a motivation to be effective, efficient and economical and to prevent abuse of the right to conduct an On-site Inspection (OSI) in the territory of a challenged State Party. In particular, it is in the interest of a State Party to avoid irrelevant search in specific areas. In this study we propose several techniques to determine `exclusion zones', which are defined as areas where an event could not have possibly occurred. All techniques are based on simple ideas of arrival time differences between seismic stations and thus are less prone to modeling errors compared to standard event location methods. The techniques proposed are: angular sector exclusion based on a tripartite micro array, half-space exclusion based on a station pair, and closed area exclusion based on circumferential networks.
Parity-Time Symmetric Photonics
Zhao, Han
2018-01-17
The establishment of non-Hermitian quantum mechanics (such as parity-time (PT) symmetry) stimulates a paradigmatic shift for studying symmetries of complex potentials. Owing to the convenient manipulation of optical gain and loss in analogy to the complex quantum potentials, photonics provides an ideal platform for visualization of many conceptually striking predictions from the non-Hermitian quantum theory. A rapidly developing field has emerged, namely, PT symmetric photonics, demonstrating intriguing optical phenomena including eigenstate coalescence and spontaneous PT symmetry breaking. The advance of quantum physics, as the feedback, provides photonics with brand-new paradigms to explore the entire complex permittivity plane for novel optical functionalities. Here, we review recent exciting breakthroughs in PT symmetric photonics while systematically presenting their underlying principles guided by non-Hermitian symmetries. The potential device applications for optical communication and computing, bio-chemical sensing, and healthcare are also discussed.
Homotheties of cylindrically symmetric static spacetimes
International Nuclear Information System (INIS)
Qadir, A.; Ziad, M.; Sharif, M.
1998-08-01
In this note we consider the homotheties of cylindrically symmetric static spacetimes. We find that we can provide a complete list of all metrics that admit non-trivial homothetic motions and are cylindrically symmetric static. (author)
Maximally Symmetric Composite Higgs Models.
Csáki, Csaba; Ma, Teng; Shu, Jing
2017-09-29
Maximal symmetry is a novel tool for composite pseudo Goldstone boson Higgs models: it is a remnant of an enhanced global symmetry of the composite fermion sector involving a twisting with the Higgs field. Maximal symmetry has far-reaching consequences: it ensures that the Higgs potential is finite and fully calculable, and also minimizes the tuning. We present a detailed analysis of the maximally symmetric SO(5)/SO(4) model and comment on its observational consequences.
DEFF Research Database (Denmark)
Søndergaard, Dorte Marie
2017-01-01
Social exclusion anxiety is a term which builds on a social-psychological concept of human beings as existentially dependent on social embeddedness. This entry explores the concept in relation to bullying among children, which is a widespread and serious problem in schools and institutions. Social...... exclusion anxiety and longing for belonging are both central aspects of the affects and processes that enact and challenge social groups. Social exclusion anxiety should not be confused with ‘social phobia’, which is a concept within clinical psychology that focuses on the individual and refers to a phobic...... psychological condition. Social exclusion anxiety instead points to a distributed affect which circulates and smolders in all social groups. This is the result of an ever-present risk of someone being judged unworthy to belong to, or deemed not a legitimate participant in, a social group. Such anxiety may...
On symmetric structures of order two
Directory of Open Access Journals (Sweden)
Michel Bousquet
2008-04-01
Full Text Available Let (ω n 0 < n be the sequence known as Integer Sequence A047749 http://www.research.att.com/ njas/sequences/A047749 In this paper, we show that the integer ω n enumerates various kinds of symmetric structures of order two. We first consider ternary trees having a reflexive symmetry and we relate all symmetric combinatorial objects by means of bijection. We then generalize the symmetric structures and correspondences to an infinite family of symmetric objects.
Communication: Symmetrical quasi-classical analysis of linear optical spectroscopy
Provazza, Justin; Coker, David F.
2018-05-01
The symmetrical quasi-classical approach for propagation of a many degree of freedom density matrix is explored in the context of computing linear spectra. Calculations on a simple two state model for which exact results are available suggest that the approach gives a qualitative description of peak positions, relative amplitudes, and line broadening. Short time details in the computed dipole autocorrelation function result in exaggerated tails in the spectrum.
Graybill, George
2007-01-01
Just how simple are simple machines? With our ready-to-use resource, they are simple to teach and easy to learn! Chocked full of information and activities, we begin with a look at force, motion and work, and examples of simple machines in daily life are given. With this background, we move on to different kinds of simple machines including: Levers, Inclined Planes, Wedges, Screws, Pulleys, and Wheels and Axles. An exploration of some compound machines follows, such as the can opener. Our resource is a real time-saver as all the reading passages, student activities are provided. Presented in s
Baryon symmetric big bang cosmology
International Nuclear Information System (INIS)
Stecker, F.W.
1978-01-01
It is stated that the framework of baryon symmetric big bang (BSBB) cosmology offers our greatest potential for deducting the evolution of the Universe because its physical laws and processes have the minimum number of arbitrary assumptions about initial conditions in the big-bang. In addition, it offers the possibility of explaining the photon-baryon ratio in the Universe and how galaxies and galaxy clusters are formed. BSBB cosmology also provides the only acceptable explanation at present for the origin of the cosmic γ-ray background radiation. (author)
Symmetric functions and orthogonal polynomials
Macdonald, I G
1997-01-01
One of the most classical areas of algebra, the theory of symmetric functions and orthogonal polynomials has long been known to be connected to combinatorics, representation theory, and other branches of mathematics. Written by perhaps the most famous author on the topic, this volume explains some of the current developments regarding these connections. It is based on lectures presented by the author at Rutgers University. Specifically, he gives recent results on orthogonal polynomials associated with affine Hecke algebras, surveying the proofs of certain famous combinatorial conjectures.
Immanant Conversion on Symmetric Matrices
Directory of Open Access Journals (Sweden)
Purificação Coelho M.
2014-01-01
Full Text Available Letr Σn(C denote the space of all n χ n symmetric matrices over the complex field C. The main objective of this paper is to prove that the maps Φ : Σn(C -> Σn (C satisfying for any fixed irre- ducible characters X, X' -SC the condition dx(A +aB = dχ·(Φ(Α + αΦ(Β for all matrices A,В ε Σ„(С and all scalars a ε C are automatically linear and bijective. As a corollary of the above result we characterize all such maps Φ acting on ΣИ(С.
Indian Academy of Sciences (India)
his exclusion principle, the quantum theory was a mess. Moreover, it could ... This is a function of all the coordinates and 'internal variables' such as spin, of all the ... must remain basically the same (ie change by a phase factor at most) if we ...
Walczak, Marek
2016-01-01
I briefly introduce so-called central exclusive production. I mainly focus on the example analyses that have been performed in the CMS experiment at CERN. I conclude with ideas and perspectives for future work that will be done during Run 2 of the LHC. I pay special attention to the ultraperipheral collisions.
Ombuds' Corner: Social exclusion
Vincent Vuillemin
2012-01-01
In this special video edition of the Ombuds' Corner, Vincent Vuillemin takes a look at a social exclusion at CERN. Please note that the characters and situations appearing in this work are fictitious, and any resemblance to real persons or events is purely coincidental. Contact the Ombuds Early!
Annette Roest; Anne Marike Lokhorst; Cok Vrooman
2010-01-01
Original title: Sociale uitsluiting bij kinderen. Combating social exclusion of children is a subject that has received growing attention in Dutch government policy in recent years. To date, however, no analysis has been performed to ascertain the extent and origins of this phenomenon. This
Energy Technology Data Exchange (ETDEWEB)
Wathen, A. [Oxford Univ. (United Kingdom); Golub, G. [Stanford Univ., CA (United States)
1996-12-31
A simple fixed point linearisation of the Navier-Stokes equations leads to the Oseen problem which after appropriate discretisation yields large sparse linear systems with coefficient matrices of the form (A B{sup T} B -C). Here A is non-symmetric but its symmetric part is positive definite, and C is symmetric and positive semi-definite. Such systems arise in other situations. In this talk we will describe and present some analysis for an iteration based on an indefinite and symmetric preconditioner of the form (D B{sup T} B -C).
Probabilistic cloning of three symmetric states
International Nuclear Information System (INIS)
Jimenez, O.; Bergou, J.; Delgado, A.
2010-01-01
We study the probabilistic cloning of three symmetric states. These states are defined by a single complex quantity, the inner product among them. We show that three different probabilistic cloning machines are necessary to optimally clone all possible families of three symmetric states. We also show that the optimal cloning probability of generating M copies out of one original can be cast as the quotient between the success probability of unambiguously discriminating one and M copies of symmetric states.
... Han M, Partin AW. Simple prostatectomy: open and robot-assisted laparoscopic approaches. In: Wein AJ, Kavoussi LR, ... M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health ...
Spherically symmetric scalar field collapse
Indian Academy of Sciences (India)
2013-03-01
Mar 1, 2013 ... The very recent interest in scalar field collapse stems from a cosmological ... The objective of the present investigation is to explore the collapsing modes of a simple ..... The authors thank the BRNS (DAE) for financial support.
Classification of symmetric toroidal orbifolds
Energy Technology Data Exchange (ETDEWEB)
Fischer, Maximilian; Ratz, Michael; Torrado, Jesus [Technische Univ. Muenchen, Garching (Germany). Physik-Department; Vaudrevange, Patrick K.S. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)
2012-09-15
We provide a complete classification of six-dimensional symmetric toroidal orbifolds which yield N{>=}1 supersymmetry in 4D for the heterotic string. Our strategy is based on a classification of crystallographic space groups in six dimensions. We find in total 520 inequivalent toroidal orbifolds, 162 of them with Abelian point groups such as Z{sub 3}, Z{sub 4}, Z{sub 6}-I etc. and 358 with non-Abelian point groups such as S{sub 3}, D{sub 4}, A{sub 4} etc. We also briefly explore the properties of some orbifolds with Abelian point groups and N=1, i.e. specify the Hodge numbers and comment on the possible mechanisms (local or non-local) of gauge symmetry breaking.
Nonlinear PT-symmetric plaquettes
International Nuclear Information System (INIS)
Li Kai; Kevrekidis, P G; Malomed, Boris A; Günther, Uwe
2012-01-01
We introduce four basic two-dimensional (2D) plaquette configurations with onsite cubic nonlinearities, which may be used as building blocks for 2D PT-symmetric lattices. For each configuration, we develop a dynamical model and examine its PTsymmetry. The corresponding nonlinear modes are analyzed starting from the Hamiltonian limit, with zero value of the gain–loss coefficient, γ. Once the relevant waveforms have been identified (chiefly, in an analytical form), their stability is examined by means of linearization in the vicinity of stationary points. This reveals diverse and, occasionally, fairly complex bifurcations. The evolution of unstable modes is explored by means of direct simulations. In particular, stable localized modes are found in these systems, although the majority of identified solutions are unstable. This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical devoted to ‘Quantum physics with non-Hermitian operators’. (paper)
PT-symmetric planar devices for field transformation and imaging
International Nuclear Information System (INIS)
Valagiannopoulos, C A; Monticone, F; Alù, A
2016-01-01
The powerful tools of transformation optics (TO) allow an effective distortion of a region of space by carefully engineering the material inhomogeneity and anisotropy, and have been successfully applied in recent years to control electromagnetic fields in many different scenarios, e.g., to realize invisibility cloaks and planar lenses. For various field transformations, it is not necessary to use volumetric inhomogeneous materials, and suitably designed ultrathin metasurfaces with tailored spatial or spectral responses may be able to realize similar functionalities within smaller footprints and more robust mechanisms. Here, inspired by the concept of metamaterial TO lenses, we discuss field transformations enabled by parity-time (PT) symmetric metasurfaces, which can emulate negative refraction. We first analyze a simple realization based on homogeneous and local metasurfaces to achieve negative refraction and imaging, and we then extend our results to arbitrary PT-symmetric two-port networks to realize aberration-free planar imaging. (paper)
International Nuclear Information System (INIS)
Ponce, W.A.; Zepeda, A.
1987-08-01
We present the results obtained from our systematic search of a simple Lie group that unifies weak and electromagnetic interactions in a single truly unified theory. We work with fractionally charged quarks, and allow for particles and antiparticles to belong to the same irreducible representation. We found that models based on SU(6), SU(7), SU(8) and SU(10) are viable candidates for simple unification. (author). 23 refs
Relativistic fluids in spherically symmetric space
International Nuclear Information System (INIS)
Dipankar, R.
1977-12-01
Some of McVittie and Wiltshire's (1977) solutions of Walker's (1935) isotropy conditions for relativistic perfect fluid spheres are generalized. Solutions are spherically symmetric and conformally flat
"Exclusive Dealing Contract and Inefficient Entry Threat"
Noriyuki Yanagawa; Ryoko Oki
2008-01-01
This paper examines the effects of exclusive dealing contracts in a simple model with manufacturers-distributors relations. We consider entrants in both manufacturing and distribution sectors. It is well-known that a potential entry threat is welfare increasing under homogenous price competition, even though the potential entrant is less productive. This paper reexamines this intuition by employing the above model. We show that the entry threat of a less-productive manufacturer is welfare dec...
International Nuclear Information System (INIS)
Mueller, A.H.
1981-01-01
In this talk I concentrate on purely exclusive processes. In Sec. II form factors and exclusive decays of heavy quarkonium states will be discussed. In Sec. III elastic wide angle elastic scattering will be considered with emphasis placed on the energy dependence for a fixed angle. The x → 1 limit of structure functions is discussed in Sec. IV. This is a limit which matches on, in a rather complicated way, with transition form factors. In Sec. V the idea of intrinsic charm is considered, mostly from a conceptual viewpoint as to its definition and possible existence. In Sec. VI there is a brief discussion of calculations of matrix elements which occur in deeply inelastic scattering by use of a bag model. In Sec. VII wee parton cancellations and Sudakov corrections for μ-pair production are considered. Sec. VIII concerns soft particle production and the mutliplicity of hadrons in a jet. (orig./HSI)
Directory of Open Access Journals (Sweden)
Troy Jollimore
2008-02-01
Full Text Available Friendship and romantic love are, by their very nature, exclusive relationships. This paper suggests that we can better understand the nature of the exclusivity in question by understanding what is wrong with the view of practical reasoning I call the Comprehensive Surveyor View. The CSV claims that practical reasoning, in order to be rational, must be a process of choosing the best available alternative from a perspective that is as detached and objective as possible. But this view, while it means to be neutral between various value-bearers, in fact incorporates a bias against those value-bearers that can only be appreciated from a perspective that is not detached—that can only be appreciated, for instance, by agents who bear long-term commitments to the values in question. In the realm of personal relationships, such commitments tend to give rise to the sort of exclusivity that characterizes friendship and romantic love; they prevent the agent from being impartial between her beloved’s needs, interests, etc., and those of other persons. In such contexts, I suggest, needs and claims of other persons may be silenced in much the way that, as John McDowell has suggested, the temptations of immorality are silenced for the virtuous agent.
Comprehensive asynchronous symmetric rendezvous algorithm in ...
Indian Academy of Sciences (India)
Meenu Chawla
2017-11-10
Nov 10, 2017 ... Simulation results affirm that CASR algorithm performs better in terms of average time-to-rendezvous as compared ... process; neighbour discovery; symmetric rendezvous algorithm. 1. .... dezvous in finite time under the symmetric model. The CH ..... CASR algorithm in Matlab 7.11 and performed several.
Signed Young Modules and Simple Specht Modules
Danz, Susanne; Lim, Kay Jin
2015-01-01
By a result of Hemmer, every simple Specht module of a finite symmetric group over a field of odd characteristic is a signed Young module. While Specht modules are parametrized by partitions, indecomposable signed Young modules are parametrized by certain pairs of partitions. The main result of this article establishes the signed Young module labels of simple Specht modules. Along the way we prove a number of results concerning indecomposable signed Young modules that are of independent inter...
Symmetric splitting of very light systems
International Nuclear Information System (INIS)
Grotowski, K.; Majka, Z.; Planeta, R.
1985-01-01
Fission reactions that produce fragments close to one half the mass of the composite system are traditionally observed in heavy nuclei. In light systems, symmetric splitting is rarely observed and poorly understood. It would be interesting to verify the existence of the symmetric splitting of compound nuclei with A 12 C + 40 Ca, 141 MeV 9 Be + 40 Ca and 153 MeV 6 Li + 40 Ca. The out-of-plane correlation of symmetric products was also measured for the reaction 186 MeV 12 C + 40 Ca. The coincidence measurements of the 12 C + 40 Ca system demonstrated that essentially all of the inclusive yield of symmetric products around 40 0 results from a binary decay. To characterize the dependence of the symmetric splitting process on the excitation energy of the 12 C + 40 C system, inclusive measurements were made at bombarding energies of 74, 132, 162, and 185 MeV
Baryon symmetric big bang cosmology
Stecker, F. W.
1978-01-01
Both the quantum theory and Einsteins theory of special relativity lead to the supposition that matter and antimatter were produced in equal quantities during the big bang. It is noted that local matter/antimatter asymmetries may be reconciled with universal symmetry by assuming (1) a slight imbalance of matter over antimatter in the early universe, annihilation, and a subsequent remainder of matter; (2) localized regions of excess for one or the other type of matter as an initial condition; and (3) an extremely dense, high temperature state with zero net baryon number; i.e., matter/antimatter symmetry. Attention is given to the third assumption, which is the simplest and the most in keeping with current knowledge of the cosmos, especially as pertains the universality of 3 K background radiation. Mechanisms of galaxy formation are discussed, whereby matter and antimatter might have collided and annihilated each other, or have coexisted (and continue to coexist) at vast distances. It is pointed out that baryon symmetric big bang cosmology could probably be proved if an antinucleus could be detected in cosmic radiation.
Substring-Searchable Symmetric Encryption
Directory of Open Access Journals (Sweden)
Chase Melissa
2015-06-01
Full Text Available In this paper, we consider a setting where a client wants to outsource storage of a large amount of private data and then perform substring search queries on the data – given a data string s and a search string p, find all occurrences of p as a substring of s. First, we formalize an encryption paradigm that we call queryable encryption, which generalizes searchable symmetric encryption (SSE and structured encryption. Then, we construct a queryable encryption scheme for substring queries. Our construction uses suffix trees and achieves asymptotic efficiency comparable to that of unencrypted suffix trees. Encryption of a string of length n takes O(λn time and produces a ciphertext of size O(λn, and querying for a substring of length m that occurs k times takes O(λm+k time and three rounds of communication. Our security definition guarantees correctness of query results and privacy of data and queries against a malicious adversary. Following the line of work started by Curtmola et al. (ACM CCS 2006, in order to construct more efficient schemes we allow the query protocol to leak some limited information that is captured precisely in the definition. We prove security of our substring-searchable encryption scheme against malicious adversaries, where the query protocol leaks limited information about memory access patterns through the suffix tree of the encrypted string.
International Nuclear Information System (INIS)
Cooper, J.R.
2003-01-01
'Everyone in the world is exposed to radiation from natural and artificial sources. Any realistic system of radiological protection must have a clearly defined scope if it is not to apply to the whole of mankind's activities'. This quote, from ICRP Publication 60 (ICRP, 1991), remains apposite. The main tool for defining scope is the concept of exclusion: situations, sources or exposures that are excluded from the system of radiological protection are, to all intents and purposes, ignored. Sources and exposures that are not excluded are within the scope of the system of protection and by inference within regulatory systems implementing ICRP recommendations. These sources and exposures should be subject to appropriate authorization by the relevant regulatory authority. In order to avoid excessive regulatory procedures, however, provisions should be made for granting an exemption in cases where it is clear that regulatory provisions are unnecessary. Exemption is a regulatory tool intended to facilitate efficient use of regulatory resources. Nevertheless, the regulatory act of granting exemptions is, in itself, a form of authorization and the material or situation so exempted remains within the regulatory system. This distinction between exclusion and exemption is an important one. Historically, the concept of exclusion has been applied to sources or exposures that are essentially unamenable to control because of their widespread nature. The usually quoted examples are cosmic radiation at ground level and 40 K in the body. Clearly, many exposures from natural sources could fall into this category. The challenges are firstly to establish a sound basis for deciding which should be excluded and which should be controlled, and secondly to see if the concept could or should be applied to artificial sources and exposures. These two questions are the subject of this paper. (author)
Beig, Robert; Siddiqui, Azad A.
2007-11-01
It is known that spherically symmetric static spacetimes admit a foliation by flat hypersurfaces. Such foliations have explicitly been constructed for some spacetimes, using different approaches, but none of them have proved or even discussed the uniqueness of these foliations. The issue of uniqueness becomes more important due to suitability of flat foliations for studying black hole physics. Here, flat spherically symmetric spacelike hypersurfaces are obtained by a direct method. It is found that spherically symmetric static spacetimes admit flat spherically symmetric hypersurfaces, and that these hypersurfaces are unique up to translation under the timelike Killing vector. This result guarantees the uniqueness of flat spherically symmetric foliations for such spacetimes.
DEFF Research Database (Denmark)
Søndergaard, Dorte Marie
2014-01-01
. The concepts I work with are the need for belonging, social exclusion anxiety and the production of contempt and dignity by both children and adults. I develop a new definition of bullying, drawing upon Judith Butler’s (1999) concept of ‘abjection’ as well as Karen Barad’s concept of ‘intra-acting forces......’ (Barad 2007). My definition in this chapter contributed to the shorter definition of bullying in the Introduction (see page XX), but it is more fully developed here in relation to the types of mechanisms and processes involved. Barad’s term ‘intra-action’ helps draw attention to the mutually...
The Topology of Three-Dimensional Symmetric Tensor Fields
Lavin, Yingmei; Levy, Yuval; Hesselink, Lambertus
1994-01-01
We study the topology of 3-D symmetric tensor fields. The goal is to represent their complex structure by a simple set of carefully chosen points and lines analogous to vector field topology. The basic constituents of tensor topology are the degenerate points, or points where eigenvalues are equal to each other. First, we introduce a new method for locating 3-D degenerate points. We then extract the topological skeletons of the eigenvector fields and use them for a compact, comprehensive description of the tensor field. Finally, we demonstrate the use of tensor field topology for the interpretation of the two-force Boussinesq problem.
Social exclusion and education
Directory of Open Access Journals (Sweden)
Jokić Vesna
2009-01-01
Full Text Available Social exclusion is a process whereby certain individuals are pushed to the edge of society and prevented from participating fully by virtue of their poverty, or lack of basic competencies and lifelong learning opportunities or as a result of discrimination. This distances them from job, income and education opportunities as well as social and community networks and activities. Quality education (conditions and access/accessibility/availability is one of the factors that significantly influence the reduced social exclusion. In other words, education has is key role key role in ensuring social inclusion (equal opportunities and active social participation. At the same time, education and lifelong learning is established as the basis for achieving the goals of sustainable economic development (economy based on knowledge and to achieve social cohesion. Quality education is a prerequisite for progress, development and well-being of the community. Conditions and accessibility to education have become priorities of national reforms in most European countries. The subject of this paper is the educational structure of population of Serbia and the accessibility of education. The analysis covers the educational structure with regard to age, gender and type of settlement (city and other/villages settlements.
Stationary states of a PT symmetric two-mode Bose–Einstein condensate
International Nuclear Information System (INIS)
Graefe, Eva-Maria
2012-01-01
The understanding of nonlinear PT symmetric quantum systems, arising for example in the theory of Bose–Einstein condensates in PT symmetric potentials, is widely based on numerical investigations, and little is known about generic features induced by the interplay of PT symmetry and nonlinearity. To gain deeper insights it is important to have analytically solvable toy models at hand. In the present paper the stationary states of a simple toy model of a PT symmetric system previously introduced in [1, 2] are investigated. The model can be interpreted as a simple description of a Bose–Einstein condensate in a PT symmetric double well trap in a two-mode approximation. The eigenvalues and eigenstates of the system can be explicitly calculated in a straightforward manner; the resulting structures resemble those that have recently been found numerically for a more realistic PT symmetric double delta potential. In addition, a continuation of the system is introduced that allows an interpretation in terms of a simple linear matrix model. This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical devoted to ‘Quantum physics with non-Hermitian operators’. (paper)
Particle in a box in PT-symmetric quantum mechanics and an electromagnetic analog
Dasarathy, Anirudh; Isaacson, Joshua P.; Jones-Smith, Katherine; Tabachnik, Jason; Mathur, Harsh
2013-06-01
In PT-symmetric quantum mechanics a fundamental principle of quantum mechanics, that the Hamiltonian must be Hermitian, is replaced by another set of requirements, including notably symmetry under PT, where P denotes parity and T denotes time reversal. Here we study the role of boundary conditions in PT-symmetric quantum mechanics by constructing a simple model that is the PT-symmetric analog of a particle in a box. The model has the usual particle-in-a-box Hamiltonian but boundary conditions that respect PT symmetry rather than Hermiticity. We find that for a broad class of PT-symmetric boundary conditions the model respects the condition of unbroken PT symmetry, namely, that the Hamiltonian and the symmetry operator PT have simultaneous eigenfunctions, implying that the energy eigenvalues are real. We also find that the Hamiltonian is self-adjoint under the PT-symmetric inner product. Thus we obtain a simple soluble model that fulfills all the requirements of PT-symmetric quantum mechanics. In the second part of this paper we formulate a variational principle for PT-symmetric quantum mechanics that is the analog of the textbook Rayleigh-Ritz principle. Finally we consider electromagnetic analogs of the PT-symmetric particle in a box. We show that the isolated particle in a box may be realized as a Fabry-Perot cavity between an absorbing medium and its conjugate gain medium. Coupling the cavity to an external continuum of incoming and outgoing states turns the energy levels of the box into sharp resonances. Remarkably we find that the resonances have a Breit-Wigner line shape in transmission and a Fano line shape in reflection; by contrast, in the corresponding Hermitian case the line shapes always have a Breit-Wigner form in both transmission and reflection.
The symmetric extendibility of quantum states
International Nuclear Information System (INIS)
Nowakowski, Marcin L
2016-01-01
Studies on the symmetric extendibility of quantum states have become particularly important in the context of the analysis of one-way quantum measures of entanglement, and the distillability and security of quantum protocols. In this paper we analyze composite systems containing a symmetric extendible part, with particular attention devoted to the one-way security of such systems. Further, we introduce a new one-way entanglement monotone based on the best symmetric approximation of a quantum state and the extendible number of a quantum state. We underpin these results with geometric observations about the structures of multi-party settings which posses substantial symmetric extendible components in their subspaces. The impossibility of reducing the maximal symmetric extendibility by means of the one-way local operations and classical communication method is pointed out on multiple copies. Finally, we state a conjecture linking symmetric extendibility with the one-way distillability and security of all quantum states, analyzing the behavior of a private key in the neighborhood of symmetric extendible states. (paper)
Averaging in spherically symmetric cosmology
International Nuclear Information System (INIS)
Coley, A. A.; Pelavas, N.
2007-01-01
The averaging problem in cosmology is of fundamental importance. When applied to study cosmological evolution, the theory of macroscopic gravity (MG) can be regarded as a long-distance modification of general relativity. In the MG approach to the averaging problem in cosmology, the Einstein field equations on cosmological scales are modified by appropriate gravitational correlation terms. We study the averaging problem within the class of spherically symmetric cosmological models. That is, we shall take the microscopic equations and effect the averaging procedure to determine the precise form of the correlation tensor in this case. In particular, by working in volume-preserving coordinates, we calculate the form of the correlation tensor under some reasonable assumptions on the form for the inhomogeneous gravitational field and matter distribution. We find that the correlation tensor in a Friedmann-Lemaitre-Robertson-Walker (FLRW) background must be of the form of a spatial curvature. Inhomogeneities and spatial averaging, through this spatial curvature correction term, can have a very significant dynamical effect on the dynamics of the Universe and cosmological observations; in particular, we discuss whether spatial averaging might lead to a more conservative explanation of the observed acceleration of the Universe (without the introduction of exotic dark matter fields). We also find that the correlation tensor for a non-FLRW background can be interpreted as the sum of a spatial curvature and an anisotropic fluid. This may lead to interesting effects of averaging on astrophysical scales. We also discuss the results of averaging an inhomogeneous Lemaitre-Tolman-Bondi solution as well as calculations of linear perturbations (that is, the backreaction) in an FLRW background, which support the main conclusions of the analysis
Linac design algorithm with symmetric segments
International Nuclear Information System (INIS)
Takeda, Harunori; Young, L.M.; Nath, S.; Billen, J.H.; Stovall, J.E.
1996-01-01
The cell lengths in linacs of traditional design are typically graded as a function of particle velocity. By making groups of cells and individual cells symmetric in both the CCDTL AND CCL, the cavity design as well as mechanical design and fabrication is simplified without compromising the performance. We have implemented a design algorithm in the PARMILA code in which cells and multi-cavity segments are made symmetric, significantly reducing the number of unique components. Using the symmetric algorithm, a sample linac design was generated and its performance compared with a similar one of conventional design
Symmetric nuclear matter with Skyrme interaction
International Nuclear Information System (INIS)
Manisa, K.; Bicer, A.; Atav, U.
2010-01-01
The equation of state (EOS) and some properties of symmetric nuclear matter, such as the saturation density, saturation energy and incompressibility, are obtained by using Skyrme's density-dependent effective nucleon-nucleon interaction.
Performance limitations of translationally symmetric nonimaging devices
Bortz, John C.; Shatz, Narkis E.; Winston, Roland
2001-11-01
The component of the optical direction vector along the symmetry axis is conserved for all rays propagated through a translationally symmetric optical device. This quality, referred to herein as the translational skew invariant, is analogous to the conventional skew invariant, which is conserved in rotationally symmetric optical systems. The invariance of both of these quantities is a consequence of Noether's theorem. We show how performance limits for translationally symmetric nonimaging optical devices can be derived from the distributions of the translational skew invariant for the optical source and for the target to which flux is to be transferred. Examples of computed performance limits are provided. In addition, we show that a numerically optimized non-tracking solar concentrator utilizing symmetry-breaking surface microstructure can overcome the performance limits associated with translational symmetry. The optimized design provides a 47.4% increase in efficiency and concentration relative to an ideal translationally symmetric concentrator.
Symmetrical parahiliar infiltrated, cough and dyspnoea
International Nuclear Information System (INIS)
Giraldo Estrada, Horacio; Escalante, Hector
2004-01-01
It is the case a patient to who is diagnosed symmetrical parahiliar infiltrated; initially she is diagnosed lymphoma Hodgkin, treaty with radiotherapy and chemotherapy, but the X rays of the thorax demonstrated parahiliars and paramediastinals infiltrated
Introduction to left-right symmetric models
International Nuclear Information System (INIS)
Grimus, W.
1993-01-01
We motivate left-right symmetric models by the possibility of spontaneous parity breaking. Then we describe the multiplets and the Lagrangian of such models. Finally we discuss lower bounds on the right-handed scale. (author)
A cosmological problem for maximally symmetric supergravity
International Nuclear Information System (INIS)
German, G.; Ross, G.G.
1986-01-01
Under very general considerations it is shown that inflationary models of the universe based on maximally symmetric supergravity with flat potentials are unable to resolve the cosmological energy density (Polonyi) problem. (orig.)
Theorem on axially symmetric gravitational vacuum configurations
Energy Technology Data Exchange (ETDEWEB)
Papadopoulos, A; Le Denmat, G [Paris-6 Univ., 75 (France). Inst. Henri Poincare
1977-01-24
A theorem is proved which asserts the non-existence of axially symmetric gravitational vacuum configurations with non-stationary rotation only. The eventual consequences in black-hole physics are suggested.
When push comes to shove: Exclusion processes with nonlocal consequences
Almet, Axel A.; Pan, Michael; Hughes, Barry D.; Landman, Kerry A.
2015-11-01
Stochastic agent-based models are useful for modelling collective movement of biological cells. Lattice-based random walk models of interacting agents where each site can be occupied by at most one agent are called simple exclusion processes. An alternative motility mechanism to simple exclusion is formulated, in which agents are granted more freedom to move under the compromise that interactions are no longer necessarily local. This mechanism is termed shoving. A nonlinear diffusion equation is derived for a single population of shoving agents using mean-field continuum approximations. A continuum model is also derived for a multispecies problem with interacting subpopulations, which either obey the shoving rules or the simple exclusion rules. Numerical solutions of the derived partial differential equations compare well with averaged simulation results for both the single species and multispecies processes in two dimensions, while some issues arise in one dimension for the multispecies case.
Symmetric Imidazolium-Based Paramagnetic Ionic Liquids
2017-11-29
Charts N/A Unclassified Unclassified Unclassified SAR 14 Kamran Ghiassi N/A 1 Symmetric Imidazolium-Based Paramagnetic Ionic Liquids Kevin T. Greeson...NUMBER (Include area code) 29 November 2017 Briefing Charts 01 November 2017 - 30 November 2017 Symmetric Imidazolium-Based Paramagnetic Ionic ... Liquids K. Greeson, K. Ghiassi, J. Alston, N. Redeker, J. Marcischak, L. Gilmore, A. Guenthner Air Force Research Laboratory (AFMC) AFRL/RQRP 9 Antares
Pion condensation in symmetric nuclear matter
International Nuclear Information System (INIS)
Kabir, K.; Saha, S.; Nath, L.M.
1987-09-01
Using a model which is based essentially on the chiral SU(2)xSU(2) symmetry of the pion-nucleon interaction, we examine the possibility of pion condensation in symmetric nucleon matter. We find that the pion condensation is not likely to occur in symmetric nuclear matter for any finite value of the nuclear density. Consequently, no critical opalescence phenomenon is expected to be seen in the pion-nucleus interaction. (author). 20 refs
Pion condensation in symmetric nuclear matter
Kabir, K.; Saha, S.; Nath, L. M.
1988-01-01
Using a model which is based essentially on the chiral SU(2)×SU(2) symmetry of the pion-nucleon interaction, we examine the possibility of pion condensation in symmetric nucleon matter. We find that the pion condensation is not likely to occur in symmetric nuclear matter for any finite value of the nuclear density. Consequently, no critical opalescence phenomenom is expected to be seen in the pion-nucleus interaction.
Marginal Stability Diagrams for Infinite-n Ballooning Modes in Quasi-symmetric Stellarators
International Nuclear Information System (INIS)
Hudson, S.R.; Hegna, C.C.; Torasso, R.; Ware, A.
2003-01-01
By perturbing the pressure and rotational-transform profiles at a selected surface in a given equilibrium, and by inducing a coordinate variation such that the perturbed state is in equilibrium, a family of magnetohydrodynamic equilibria local to the surface and parameterized by the pressure gradient and shear is constructed for arbitrary stellarator geometry. The geometry of the surface is not changed. The perturbed equilibria are analyzed for infinite-n ballooning stability and marginal stability diagrams are constructed that are analogous to the (s; alpha) diagrams constructed for axi-symmetric configurations. The method describes how pressure and rotational-transform gradients influence the local shear, which in turn influences the ballooning stability. Stability diagrams for the quasi-axially-symmetric NCSX (National Compact Stellarator Experiment), a quasi-poloidally-symmetric configuration and the quasi-helically-symmetric HSX (Helically Symmetric Experiment) are presented. Regions of second-stability are observed in both NCSX and the quasi-poloidal configuration, whereas no second stable region is observed for the quasi-helically symmetric device. To explain the different regions of stability, the curvature and local shear of the quasi-poloidal configuration are analyzed. The results are seemingly consistent with the simple explanation: ballooning instability results when the local shear is small in regions of bad curvature. Examples will be given that show that the structure, and stability, of the ballooning mode is determined by the structure of the potential function arising in the Schroedinger form of the ballooning equation
Generalized exclusion and Hopf algebras
International Nuclear Information System (INIS)
Yildiz, A
2002-01-01
We propose a generalized oscillator algebra at the roots of unity with generalized exclusion and we investigate the braided Hopf structure. We find that there are two solutions: these are the generalized exclusions of the bosonic and fermionic types. We also discuss the covariance properties of these oscillators
Evaluating Alternatives to Exclusive "He."
Todd-Mancillas, William R.
A study was conducted to determine the effects on reading comprehension of the use of the exclusive pronoun "he" and more or less contrived alternatives. Subjects, 358 students enrolled in an introduction to human communication at a large northeastern university, read three different forms of the same essay. One essay form exclusively used "he,"…
The Pauli exclusion principle origin, verifications and applications
Kaplan, Ilya G
2017-01-01
This is the first scientific book devoted to the Pauli Exclusion Principle, which is a fundamental principle of quantum mechanics and is permanently applied in chemistry, physics, molecular biology and in physical astronomy. However, while the principle has been studied for more than 90 years, rigorous theoretical foundations still have not been established and many unsolved problems remain. Following an introduction and historical survey, this book discusses the still unresolved questions around this fundamental principle. For instance, why, according to the Pauli Exclusion Principle, are only symmetric and antisymmetric permutation symmetries for identical particles realized, while the Schrödinger equation is satisfied by functions with any permutation symmetry? Chapter 3 covers possible answers to this, while chapter 4 presents effective and elegant methods for finding the Pauli-allowed states in atomic, molecular and nuclear spectroscopy. Chapter 5 discusses parastatistics and fractional statistics, dem...
The Point Zoro Symmetric Single-Step Procedure for Simultaneous Estimation of Polynomial Zeros
Directory of Open Access Journals (Sweden)
Mansor Monsi
2012-01-01
Full Text Available The point symmetric single step procedure PSS1 has R-order of convergence at least 3. This procedure is modified by adding another single-step, which is the third step in PSS1. This modified procedure is called the point zoro symmetric single-step PZSS1. It is proven that the R-order of convergence of PZSS1 is at least 4 which is higher than the R-order of convergence of PT1, PS1, and PSS1. Hence, computational time is reduced since this procedure is more efficient for bounding simple zeros simultaneously.
Crossing-symmetric solutions to low equations
International Nuclear Information System (INIS)
McLeod, R.J.; Ernst, D.J.
1985-01-01
Crossing symmetric models of the pion-nucleon interaction in which crossing symmetry is kept to lowest order in msub(π)/msub(N) are investigated. Two iterative techniques are developed to solve the crossing-symmetric Low equation. The techniques are used to solve the original Chew-Low equations and their generalizations to include the coupling to the pion-production channels. Small changes are found in comparison with earlier results which used an iterative technique proposed by Chew and Low and which did not produce crossing-symmetric results. The iterative technique of Chew and Low is shown to fail because of its inability to produce zeroes in the amplitude at complex energies while physical solutions to the model require such zeroes. We also prove that, within the class of solutions such that phase shifts approach zero for infinite energy, the solution to the Low equation is unique. (orig.)
PT symmetric Aubry–Andre model
International Nuclear Information System (INIS)
Yuce, C.
2014-01-01
PT symmetric Aubry–Andre model describes an array of N coupled optical waveguides with position-dependent gain and loss. We show that the reality of the spectrum depends sensitively on the degree of quasi-periodicity for small number of lattice sites. We obtain the Hofstadter butterfly spectrum and discuss the existence of the phase transition from extended to localized states. We show that rapidly changing periodical gain/loss materials almost conserve the total intensity. - Highlights: • We show that PT symmetric Aubry–Andre model may have real spectrum. • We show that the reality of the spectrum depends sensitively on the degree of disorder. • We obtain the Hofstadter butterfly spectrum for PT symmetric Aubry–Andre model. • We discuss that phase transition from extended to localized states exists
PT symmetric Aubry–Andre model
Energy Technology Data Exchange (ETDEWEB)
Yuce, C., E-mail: cyuce@anadolu.edu.tr
2014-06-13
PT symmetric Aubry–Andre model describes an array of N coupled optical waveguides with position-dependent gain and loss. We show that the reality of the spectrum depends sensitively on the degree of quasi-periodicity for small number of lattice sites. We obtain the Hofstadter butterfly spectrum and discuss the existence of the phase transition from extended to localized states. We show that rapidly changing periodical gain/loss materials almost conserve the total intensity. - Highlights: • We show that PT symmetric Aubry–Andre model may have real spectrum. • We show that the reality of the spectrum depends sensitively on the degree of disorder. • We obtain the Hofstadter butterfly spectrum for PT symmetric Aubry–Andre model. • We discuss that phase transition from extended to localized states exists.
All-optical symmetric ternary logic gate
Chattopadhyay, Tanay
2010-09-01
Symmetric ternary number (radix=3) has three logical states (1¯, 0, 1). It is very much useful in carry free arithmetical operation. Beside this, the logical operation using this type of number system is also effective in high speed computation and communication in multi-valued logic. In this literature all-optical circuits for three basic symmetrical ternary logical operations (inversion, MIN and MAX) are proposed and described. Numerical simulation verifies the theoretical model. In this present scheme the different ternary logical states are represented by different polarized state of light. Terahertz optical asymmetric demultiplexer (TOAD) based interferometric switch has been used categorically in this manuscript.
Symmetry theorems via the continuous steiner symmetrization
Directory of Open Access Journals (Sweden)
L. Ragoub
2000-06-01
Full Text Available Using a new approach due to F. Brock called the Steiner symmetrization, we show first that if $u$ is a solution of an overdetermined problem in the divergence form satisfying the Neumann and non-constant Dirichlet boundary conditions, then $Omega$ is an N-ball. In addition, we show that we can relax the condition on the value of the Dirichlet boundary condition in the case of superharmonicity. Finally, we give an application to positive solutions of some semilinear elliptic problems in symmetric domains for the divergence case.
The Axially Symmetric One-Monopole
International Nuclear Information System (INIS)
Wong, K.-M.; Teh, Rosy
2009-01-01
We present new classical generalized one-monopole solution of the SU(2) Yang-Mills-Higgs theory with the Higgs field in the adjoint representation. We show that this solution with θ-winding number m = 1 and φ-winding number n = 1 is an axially symmetric generalization of the 't Hooft-Polyakov one-monopole. We construct this axially symmetric one-monopole solution by generalizing the large distance asymptotic solutions of the 't Hooft-Polyakov one-monopole to the Jacobi elliptic functions and solving the second order equations of motion numerically when the Higgs potential is vanishing. This solution is a non-BPS solution.
Symmetric splitting of very light systems
International Nuclear Information System (INIS)
Grotowski, K.; Majka, Z.; Planeta, R.
1984-01-01
Inclusive and coincidence measurements have been performed to study symmetric products from the reactions 74--186 MeV 12 C+ 40 Ca, 141 MeV 9 Be+ 40 Ca, and 153 MeV 6 Li+ 40 Ca. The binary decay of the composite system has been verified. Energy spectra, angular distributions, and fragment correlations are presented. The total kinetic energies for the symmetric products from these very light composite systems are compared to liquid drop model calculations and fission systematics
The theory of spherically symmetric thin shells in conformal gravity
Berezin, Victor; Dokuchaev, Vyacheslav; Eroshenko, Yury
The spherically symmetric thin shells are the nearest generalizations of the point-like particles. Moreover, they serve as the simple sources of the gravitational fields both in General Relativity and much more complex quadratic gravity theories. We are interested in the special and physically important case when all the quadratic in curvature tensor (Riemann tensor) and its contractions (Ricci tensor and scalar curvature) terms are present in the form of the square of Weyl tensor. By definition, the energy-momentum tensor of the thin shell is proportional to Diracs delta-function. We constructed the theory of the spherically symmetric thin shells for three types of gravitational theories with the shell: (1) General Relativity; (2) Pure conformal (Weyl) gravity where the gravitational part of the total Lagrangian is just the square of the Weyl tensor; (3) Weyl-Einstein gravity. The results are compared with these in General Relativity (Israel equations). We considered in detail the shells immersed in the vacuum. Some peculiar properties of such shells are found. In particular, for the traceless ( = massless) shell, it is shown that their dynamics cannot be derived from the matching conditions and, thus, is completely arbitrary. On the contrary, in the case of the Weyl-Einstein gravity, the trajectory of the same type of shell is completely restored even without knowledge of the outside solution.
Thermoacoustic focusing lens by symmetric Airy beams with phase manipulations
Liu, Chen; Xia, Jian-Ping; Sun, Hong-Xiang; Yuan, Shou-Qi
2017-12-01
We report the realization of broadband acoustic focusing lenses based on two symmetric thermoacoustic phased arrays of Airy beams, in which the units of thermoacoustic phase control are designed by employing air with different temperatures surrounded by rigid insulated boundaries and thermal insulation films. The phase delays of the transmitted and reflected units could cover a whole 2π interval, which arises from the change of the sound velocity of air induced by the variation of the temperature. Based on the units of phase control, we design the transmitted and reflected acoustic focusing lenses with two symmetric Airy beams, and verify the high self-healing focusing characteristic and the feasibility of the thermal insulation films. Besides, the influences of the bending angle of the Airy beam on the focusing performance are discussed in detail. The proposed acoustic lens has advantages of broad bandwidth (about 4.8 kHz), high focusing performance, self-healing feature, and simple structure, which enable it to provide more schemes for acoustic focusing. It has excellent potential applications in acoustic devices.
Markov Jump Processes Approximating a Non-Symmetric Generalized Diffusion
International Nuclear Information System (INIS)
Limić, Nedžad
2011-01-01
Consider a non-symmetric generalized diffusion X(⋅) in ℝ d determined by the differential operator A(x) = -Σ ij ∂ i a ij (x)∂ j + Σ i b i (x)∂ i . In this paper the diffusion process is approximated by Markov jump processes X n (⋅), in homogeneous and isotropic grids G n ⊂ℝ d , which converge in distribution in the Skorokhod space D([0,∞),ℝ d ) to the diffusion X(⋅). The generators of X n (⋅) are constructed explicitly. Due to the homogeneity and isotropy of grids, the proposed method for d≥3 can be applied to processes for which the diffusion tensor {a ij (x)} 11 dd fulfills an additional condition. The proposed construction offers a simple method for simulation of sample paths of non-symmetric generalized diffusion. Simulations are carried out in terms of jump processes X n (⋅). For piece-wise constant functions a ij on ℝ d and piece-wise continuous functions a ij on ℝ 2 the construction and principal algorithm are described enabling an easy implementation into a computer code.
Spherical aberration correction with threefold symmetric line currents.
Hoque, Shahedul; Ito, Hiroyuki; Nishi, Ryuji; Takaoka, Akio; Munro, Eric
2016-02-01
It has been shown that N-fold symmetric line current (henceforth denoted as N-SYLC) produces 2N-pole magnetic fields. In this paper, a threefold symmetric line current (N3-SYLC in short) is proposed for correcting 3rd order spherical aberration of round lenses. N3-SYLC can be realized without using magnetic materials, which makes it free of the problems of hysteresis, inhomogeneity and saturation. We investigate theoretically the basic properties of an N3-SYLC configuration which can in principle be realized by simple wires. By optimizing the parameters of a system with beam energy of 5.5keV, the required excitation current for correcting 3rd order spherical aberration coefficient of 400 mm is less than 1AT, and the residual higher order aberrations can be kept sufficiently small to obtain beam size of less than 1 nm for initial slopes up to 5 mrad. Copyright © 2015 Elsevier B.V. All rights reserved.
Problems of Chernobyl Exclusion Zone
International Nuclear Information System (INIS)
Kholosha, V.Yi.
2014-01-01
The collection comprises the results of researches and design activity in the ChNPP exclusion zone, aimed at the development of technologies, equipment and devices for radioactive waste management and ChNPP accident clean-up, at studying the composition and structure of the Exclusion zone soil activity solid bearers, form transformation of the fission products of fuel fallout radionuclide composition in the ChNPP near zone, the spatial distribution of radionuclides and other radioecological issues.. Much attention is paid to medical and biological aspects of the accident influence on the flora, fauna and people's health, labour conditions and incidence of the workers of the Exclusion zone
Small diameter symmetric networks from linear groups
Campbell, Lowell; Carlsson, Gunnar E.; Dinneen, Michael J.; Faber, Vance; Fellows, Michael R.; Langston, Michael A.; Moore, James W.; Multihaupt, Andrew P.; Sexton, Harlan B.
1992-01-01
In this note is reported a collection of constructions of symmetric networks that provide the largest known values for the number of nodes that can be placed in a network of a given degree and diameter. Some of the constructions are in the range of current potential engineering significance. The constructions are Cayley graphs of linear groups obtained by experimental computation.
Sobolev spaces on bounded symmetric domains
Czech Academy of Sciences Publication Activity Database
Engliš, Miroslav
Roč. 60, č. 12 ( 2015 ), s. 1712-1726 ISSN 1747-6933 Institutional support: RVO:67985840 Keywords : bounded symmetric domain * Sobolev space * Bergman space Subject RIV: BA - General Mathematics Impact factor: 0.466, year: 2015 http://www.tandfonline.com/doi/abs/10.1080/17476933. 2015 .1043910
Cuspidal discrete series for semisimple symmetric spaces
DEFF Research Database (Denmark)
Andersen, Nils Byrial; Flensted-Jensen, Mogens; Schlichtkrull, Henrik
2012-01-01
We propose a notion of cusp forms on semisimple symmetric spaces. We then study the real hyperbolic spaces in detail, and show that there exists both cuspidal and non-cuspidal discrete series. In particular, we show that all the spherical discrete series are non-cuspidal. (C) 2012 Elsevier Inc. All...
Exact solutions of the spherically symmetric multidimensional ...
African Journals Online (AJOL)
The complete orthonormalised energy eigenfunctions and the energy eigenvalues of the spherically symmetric isotropic harmonic oscillator in N dimensions, are obtained through the methods of separation of variables. Also, the degeneracy of the energy levels are examined. KEY WORDS: - Schrödinger Equation, Isotropic ...
Super-symmetric informationally complete measurements
Energy Technology Data Exchange (ETDEWEB)
Zhu, Huangjun, E-mail: hzhu@pitp.ca
2015-11-15
Symmetric informationally complete measurements (SICs in short) are highly symmetric structures in the Hilbert space. They possess many nice properties which render them an ideal candidate for fiducial measurements. The symmetry of SICs is intimately connected with the geometry of the quantum state space and also has profound implications for foundational studies. Here we explore those SICs that are most symmetric according to a natural criterion and show that all of them are covariant with respect to the Heisenberg–Weyl groups, which are characterized by the discrete analog of the canonical commutation relation. Moreover, their symmetry groups are subgroups of the Clifford groups. In particular, we prove that the SIC in dimension 2, the Hesse SIC in dimension 3, and the set of Hoggar lines in dimension 8 are the only three SICs up to unitary equivalence whose symmetry groups act transitively on pairs of SIC projectors. Our work not only provides valuable insight about SICs, Heisenberg–Weyl groups, and Clifford groups, but also offers a new approach and perspective for studying many other discrete symmetric structures behind finite state quantum mechanics, such as mutually unbiased bases and discrete Wigner functions.
Harmonic maps of the bounded symmetric domains
International Nuclear Information System (INIS)
Xin, Y.L.
1994-06-01
A shrinking property of harmonic maps into R IV (2) is proved which is used to classify complete spacelike surfaces of the parallel mean curvature in R 4 2 with a reasonable condition on the Gauss image. Liouville-type theorems of harmonic maps from the higher dimensional bounded symmetric domains are also established. (author). 25 refs
On isotropic cylindrically symmetric stellar models
International Nuclear Information System (INIS)
Nolan, Brien C; Nolan, Louise V
2004-01-01
We attempt to match the most general cylindrically symmetric vacuum spacetime with a Robertson-Walker interior. The matching conditions show that the interior must be dust filled and that the boundary must be comoving. Further, we show that the vacuum region must be polarized. Imposing the condition that there are no trapped cylinders on an initial time slice, we can apply a result of Thorne's and show that trapped cylinders never evolve. This results in a simplified line element which we prove to be incompatible with the dust interior. This result demonstrates the impossibility of the existence of an isotropic cylindrically symmetric star (or even a star which has a cylindrically symmetric portion). We investigate the problem from a different perspective by looking at the expansion scalars of invariant null geodesic congruences and, applying to the cylindrical case, the result that the product of the signs of the expansion scalars must be continuous across the boundary. The result may also be understood in relation to recent results about the impossibility of the static axially symmetric analogue of the Einstein-Straus model
The Mathematics of Symmetrical Factorial Designs
Indian Academy of Sciences (India)
The Mathematics of Symmetrical Factorial Designs. Mausumi Bose (nee Sen) obtained her MSc degree in. Statistics from the Calcutta. University and PhD degree from the Indian Statistical. Institute. She is on the faculty of the Indian. Statistical Institute. Her main field of research interest is design and analysis of experiments.
Symmetric intersections of Rauzy fractals | Sellami | Quaestiones ...
African Journals Online (AJOL)
In this article we study symmetric subsets of Rauzy fractals of unimodular irreducible Pisot substitutions. The symmetry considered is re ection through the origin. Given an unimodular irreducible Pisot substitution, we consider the intersection of its Rauzy fractal with the Rauzy fractal of the reverse substitution. This set is ...
Fourier inversion on a reductive symmetric space
Ban, E.P. van den
1999-01-01
Let X be a semisimple symmetric space. In previous papers, [8] and [9], we have dened an explicit Fourier transform for X and shown that this transform is injective on the space C 1 c (X) ofcompactly supported smooth functions on X. In the present paper, which is a continuation of these papers, we
A viewpoint on nearly conformally symmetric manifold
International Nuclear Information System (INIS)
Rahman, M.S.
1990-06-01
Some observations, with definition, on Nearly Conformally Symmetric (NCS) manifold are made. A number of theorems concerning conformal change of metric and parallel tensors on NCS manifolds are presented. It is illustrated that a manifold M = R n-1 x R + 1 , endowed with a special metric, is NCS but not of harmonic curvature. (author). 8 refs
Harmonic analysis on reductive symmetric spaces
Ban, E.P. van den; Schlichtkrull, H.
2000-01-01
We give a relatively non-technical survey of some recent advances in the Fourier theory for semisimple symmetric spaces. There are three major results: An inversion formula for the Fourier transform, a Palley-Wiener theorem, which describes the Fourier image of the space of completely supported
Fourier transforms on a semisimple symmetric space
Ban, E.P. van den; Schlichtkrull, H.
1994-01-01
Let G=H be a semisimple symmetric space, that is, G is a connected semisimple real Lie group with an involution ?, and H is an open subgroup of the group of xed points for ? in G. The main purpose of this paper is to study an explicit Fourier transform on G=H. In terms of general representation
Fourier transforms on a semisimple symmetric space
Ban, E.P. van den; Carmona, J.; Delorme, P.
1997-01-01
Let G=H be a semisimple symmetric space, that is, G is a connected semisimple real Lie group with an involution ?, and H is an open subgroup of the group of xed points for ? in G. The main purpose of this paper is to study an explicit Fourier transform on G=H. In terms of general representation
Capacity Bounds and Mapping Design for Binary Symmetric Relay Channels
Directory of Open Access Journals (Sweden)
Majid Nasiri Khormuji
2012-12-01
Full Text Available Capacity bounds for a three-node binary symmetric relay channel with orthogonal components at the destination are studied. The cut-set upper bound and the rates achievable using decode-and-forward (DF, partial DF and compress-and-forward (CF relaying are first evaluated. Then relaying strategies with finite memory-length are considered. An efficient algorithm for optimizing the relay functions is presented. The Boolean Fourier transform is then employed to unveil the structure of the optimized mappings. Interestingly, the optimized relay functions exhibit a simple structure. Numerical results illustrate that the rates achieved using the optimized low-dimensional functions are either comparable to those achieved by CF or superior to those achieved by DF relaying. In particular, the optimized low-dimensional relaying scheme can improve on DF relaying when the quality of the source-relay link is worse than or comparable to that of other links.
Waterbomb base: a symmetric single-vertex bistable origami mechanism
International Nuclear Information System (INIS)
Hanna, Brandon H; Lund, Jason M; Magleby, Spencer P; Howell, Larry L; Lang, Robert J
2014-01-01
The origami waterbomb base is a single-vertex bistable origami mechanism that has unique properties which may prove useful in a variety of applications. It also shows promise as a test bed for smart materials and actuation because of its straightforward geometry and multiple phases of motion, ranging from simple to more complex. This study develops a quantitative understanding of the symmetric waterbomb base's kinetic behavior. This is done by completing kinematic and potential energy analyses to understand and predict bistable behavior. A physical prototype is constructed and tested to validate the results of the analyses. Finite element and virtual work analyses based on the prototype are used to explore the locations of the stable equilibrium positions and the force–deflection response. The model results are verified through comparisons to measurements on a physical prototype. The resulting models describe waterbomb base behavior and provide an engineering tool for application development. (paper)
Exclusive Rights and State Aid
DEFF Research Database (Denmark)
Ølykke, Grith Skovgaard
2017-01-01
Exclusive rights are granted in order to regulate markets as one of several possible tools of public intervention. The article considers the role of State aid law in the regulation of exclusive rights. Whereas the right of Member States to organise markets as monopolies and the choice of provider...... are regulated by free movement rules and Article 106 TFEU, State aid law regulates the terms of the right to ensure that the beneficiary is not granted an economic advantage. Exclusive rights may be granted on various terms: for a payment, in combination with compensation or as compensation. The two former...... kinds of terms are regulated under State aid law which requires market terms. The granting of exclusive rights as compensation is analysed on the basis of the Eventech judgment, and it is found that when no financial transaction is included in the grant, it resembles a decision to organise a market...
Exclusive processes at Jefferson Lab
Indian Academy of Sciences (India)
There is no clear guidance from theory as to the limits of the transition region; .... behavior in exclusive photoreactions with hadrons in the final state at large t may provide .... The planned medium acceptance detector (MAD) system in Hall A.
Central Exclusive Production at LHCb
INSPIRE-00106463
2015-01-01
Central Exclusive Production is a unique QCD process in which particles are produced via colourless propagators. Several results have been obtained at LHCb for the production of single charmonia, pairs of charmonia, and single bottomonia.
Central Exclusive Production at LHCb
AUTHOR|(INSPIRE)INSPIRE-00392425
2017-01-01
The LHCb detector, with its excellent momentum resolution and flexible trigger strategy, is ideally suited for measuring particles produced exclusively. In addition, a new system of forward shower counters has been installed upstream and downstream of the detector, and has been used to facilitate studies of Central Exclusive Production. Such measurements of integrated and differential cross-section in both Run 1 and Run 2 of the LHC, are summarised here.
Exclusive Territories and Manufacturers’ Collusion
Salvatore Piccolo; Markus Reisinger
2010-01-01
This paper highlights the rationale for exclusive territories in a model of repeated interaction between competing supply chains. We show that with observable contracts exclusive territories have two countervailing effects on manufacturers' incentives to sustain tacit collusion. First, granting local monopolies to retailers distributing a given brand softens inter- and intrabrand competition in a one-shot game. Hence, punishment profits are larger, thereby rendering deviation more profitable....
Exclusion statistics and integrable models
International Nuclear Information System (INIS)
Mashkevich, S.
1998-01-01
The definition of exclusion statistics, as given by Haldane, allows for a statistical interaction between distinguishable particles (multi-species statistics). The thermodynamic quantities for such statistics ca be evaluated exactly. The explicit expressions for the cluster coefficients are presented. Furthermore, single-species exclusion statistics is realized in one-dimensional integrable models. The interesting questions of generalizing this correspondence onto the higher-dimensional and the multi-species cases remain essentially open
Weakly Interacting Symmetric and Anti-Symmetric States in the Bilayer Systems
Marchewka, M.; Sheregii, E. M.; Tralle, I.; Tomaka, G.; Ploch, D.
We have studied the parallel magneto-transport in DQW-structures of two different potential shapes: quasi-rectangular and quasi-triangular. The quantum beats effect was observed in Shubnikov-de Haas (SdH) oscillations for both types of the DQW structures in perpendicular magnetic filed arrangement. We developed a special scheme for the Landau levels energies calculation by means of which we carried out the necessary simulations of beating effect. In order to obtain the agreement between our experimental data and the results of simulations, we introduced two different quasi-Fermi levels which characterize symmetric and anti-symmetric states in DQWs. The existence of two different quasi Fermi-Levels simply means, that one can treat two sub-systems (charge carriers characterized by symmetric and anti-symmetric wave functions) as weakly interacting and having their own rate of establishing the equilibrium state.
A simple application of the Newman-Penrose spin coefficient formalism
International Nuclear Information System (INIS)
Davis, T.M.
1976-01-01
As a simple application of the Newman-Penrose spin coefficient formalism, useful for beginners, the vacuum symmetry (Schwarzschild) solution is found. The calculations also show that all spherically symmetric metrics are Petrov type D. (author)
Dynamics of non-Markovian exclusion processes
International Nuclear Information System (INIS)
Khoromskaia, Diana; Grosskinsky, Stefan; Harris, Rosemary J
2014-01-01
Driven diffusive systems are often used as simple discrete models of collective transport phenomena in physics, biology or social sciences. Restricting attention to one-dimensional geometries, the asymmetric simple exclusion process (ASEP) plays a paradigmatic role to describe noise-activated driven motion of entities subject to an excluded volume interaction and many variants have been studied in recent years. While in the standard ASEP the noise is Poissonian and the process is therefore Markovian, in many applications the statistics of the activating noise has a non-standard distribution with possible memory effects resulting from internal degrees of freedom or external sources. This leads to temporal correlations and can significantly affect the shape of the current-density relation as has been studied recently for a number of scenarios. In this paper we report a general framework to derive the fundamental diagram of ASEPs driven by non-Poissonian noise by using effectively only two simple quantities, viz., the mean residual lifetime of the jump distribution and a suitably defined temporal correlation length. We corroborate our results by detailed numerical studies for various noise statistics under periodic boundary conditions and discuss how our approach can be applied to more general driven diffusive systems. (paper)
Dynamics of non-Markovian exclusion processes
Khoromskaia, Diana; Harris, Rosemary J.; Grosskinsky, Stefan
2014-12-01
Driven diffusive systems are often used as simple discrete models of collective transport phenomena in physics, biology or social sciences. Restricting attention to one-dimensional geometries, the asymmetric simple exclusion process (ASEP) plays a paradigmatic role to describe noise-activated driven motion of entities subject to an excluded volume interaction and many variants have been studied in recent years. While in the standard ASEP the noise is Poissonian and the process is therefore Markovian, in many applications the statistics of the activating noise has a non-standard distribution with possible memory effects resulting from internal degrees of freedom or external sources. This leads to temporal correlations and can significantly affect the shape of the current-density relation as has been studied recently for a number of scenarios. In this paper we report a general framework to derive the fundamental diagram of ASEPs driven by non-Poissonian noise by using effectively only two simple quantities, viz., the mean residual lifetime of the jump distribution and a suitably defined temporal correlation length. We corroborate our results by detailed numerical studies for various noise statistics under periodic boundary conditions and discuss how our approach can be applied to more general driven diffusive systems.
Women in Chernobyl Exclusion Zone
International Nuclear Information System (INIS)
Balashevska, Y.; Kireev, S.; Navalikhin, V.
2015-01-01
Today, 29 years after the Chernobyl accident, the Exclusion Zone still remains an areal unsealed radiation source of around 2600 km"2. It is not just a gigantic radioactive waste storage facility (the amount of radioactive waste accumulated within the Zone, except for the Shelter, is estimated at about 2.8 million m"3), but also a unique research and engineering platform for biologists, radiologists, chemists and physicists. Taking into account the amount of the radionuclides released during the accident, it becomes quite understood that the radiological environment in the Exclusion Zone is far from favorable. However, among the Exclusion Zone personnel who numbers 5000, there are female workers. The poster represents the results of the research performed among the female employees of the largest enterprise of the Exclusion Zone, “Chornobyl Spetskombinat”. The survey was performed with the view to knowing what makes women work in the most radioactively contaminated area in Europe, and what their role is, to revealing their fears and hopes, and to estimating the chances of the brave women of Chernobyl Exclusion Zone to succeed in their careers. (author)
RELIGIOUS EXCLUSIVITY AND PSYCHOSOCIAL FUNCTIONING.
Gegelashvili, M; Meca, A; Schwartz, S J
2015-01-01
In the present study we sought to clarify links between religious exclusivity, as form of intergroup favoritism, and indices of psychosocial functioning. The study of in group favoritism has generally been invoked within Social Identity Theory and related perspectives. However, there is a lack of literature regarding religious exclusivity from the standpoint of social identity. In particular, the ways in which religious exclusivity is linked with other dimensions of religious belief and practice, and with psychosocial functioning, among individuals from different religious backgrounds are not well understood. A sample of 8545 emerging-adult students from 30 U.S. universities completed special measures. Measure of religious exclusivity was developed and validated for this group. The results suggest that exclusivity appears as predictor for impaired psychosocial functioning, low self-esteem and low psychosocial well-being for individuals from organized faiths, as well as for those identifying as agnostic, atheist, or spiritual/nonreligious. These findings are discussed in terms of Social Identity Theory and Terror Management Theory (TMT).
Representations of the infinite symmetric group
Borodin, Alexei
2016-01-01
Representation theory of big groups is an important and quickly developing part of modern mathematics, giving rise to a variety of important applications in probability and mathematical physics. This book provides the first concise and self-contained introduction to the theory on the simplest yet very nontrivial example of the infinite symmetric group, focusing on its deep connections to probability, mathematical physics, and algebraic combinatorics. Following a discussion of the classical Thoma's theorem which describes the characters of the infinite symmetric group, the authors describe explicit constructions of an important class of representations, including both the irreducible and generalized ones. Complete with detailed proofs, as well as numerous examples and exercises which help to summarize recent developments in the field, this book will enable graduates to enhance their understanding of the topic, while also aiding lecturers and researchers in related areas.
Symmetric, discrete fractional splines and Gabor systems
DEFF Research Database (Denmark)
Søndergaard, Peter Lempel
2006-01-01
In this paper we consider fractional splines as windows for Gabor frames. We introduce two new types of symmetric, fractional splines in addition to one found by Unser and Blu. For the finite, discrete case we present two families of splines: One is created by sampling and periodizing the continu......In this paper we consider fractional splines as windows for Gabor frames. We introduce two new types of symmetric, fractional splines in addition to one found by Unser and Blu. For the finite, discrete case we present two families of splines: One is created by sampling and periodizing...... the continuous splines, and one is a truly finite, discrete construction. We discuss the properties of these splines and their usefulness as windows for Gabor frames and Wilson bases....
Overlap-free symmetric D 0 Lwords
Directory of Open Access Journals (Sweden)
Anna Frid
2001-12-01
Full Text Available A D0L word on an alphabet Σ={0,1,…,q-1} is called symmetric if it is a fixed point w=φ(w of a morphism φ:Σ * → Σ * defined by φ(i= t 1 + i t 2 + i … t m + i for some word t 1 t 2 … t m (equal to φ(0 and every i ∈ Σ; here a means a mod q. We prove a result conjectured by J. Shallit: if all the symbols in φ(0 are distinct (i.e., if t i ≠ t j for i ≠ j, then the symmetric D0L word w is overlap-free, i.e., contains no factor of the form axaxa for any x ∈ Σ * and a ∈ Σ.
Young—Capelli symmetrizers in superalgebras†
Brini, Andrea; Teolis, Antonio G. B.
1989-01-01
Let Supern[U [unk] V] be the nth homogeneous subspace of the supersymmetric algebra of U [unk] V, where U and V are Z2-graded vector spaces over a field K of characteristic zero. The actions of the general linear Lie superalgebras pl(U) and pl(V) span two finite-dimensional K-subalgebras B and [unk] of EndK(Supern[U [unk] V]) that are the centralizers of each other. Young—Capelli symmetrizers and Young—Capelli *-symmetrizers give rise to K-linear bases of B and [unk] containing orthogonal systems of idempotents; thus they yield complete decompositions of B and [unk] into minimal left and right ideals, respectively. PMID:16594014
Factored Facade Acquisition using Symmetric Line Arrangements
Ceylan, Duygu
2012-05-01
We introduce a novel framework for image-based 3D reconstruction of urban buildings based on symmetry priors. Starting from image-level edges, we generate a sparse and approximate set of consistent 3D lines. These lines are then used to simultaneously detect symmetric line arrangements while refining the estimated 3D model. Operating both on 2D image data and intermediate 3D feature representations, we perform iterative feature consolidation and effective outlier pruning, thus eliminating reconstruction artifacts arising from ambiguous or wrong stereo matches. We exploit non-local coherence of symmetric elements to generate precise model reconstructions, even in the presence of a significant amount of outlier image-edges arising from reflections, shadows, outlier objects, etc. We evaluate our algorithm on several challenging test scenarios, both synthetic and real. Beyond reconstruction, the extracted symmetry patterns are useful towards interactive and intuitive model manipulations.
Commutative curvature operators over four-dimensional generalized symmetric
Directory of Open Access Journals (Sweden)
Ali Haji-Badali
2014-12-01
Full Text Available Commutative properties of four-dimensional generalized symmetric pseudo-Riemannian manifolds were considered. Specially, in this paper, we studied Skew-Tsankov and Jacobi-Tsankov conditions in 4-dimensional pseudo-Riemannian generalized symmetric manifolds.
Strangeness Suppression of qq ¯ Creation Observed in Exclusive Reactions
Mestayer, M. D.; Park, K.; Adhikari, K. P.; Aghasyan, M.; Pereira, S. Anefalos; Ball, J.; Battaglieri, M.; Batourine, V.; Bedlinskiy, I.; Biselli, A. S.; Boiarinov, S.; Briscoe, W. J.; Brooks, W. K.; Burkert, V. D.; Carman, D. S.; Celentano, A.; Chandavar, S.; Charles, G.; Colaneri, L.; Cole, P. L.; Contalbrigo, M.; Cortes, O.; Crede, V.; D'Angelo, A.; Dashyan, N.; De Vita, R.; Deur, A.; Djalali, C.; Doughty, D.; Dupre, R.; Alaoui, A. El; Fassi, L. El; Elouadrhiri, L.; Eugenio, P.; Fedotov, G.; Fleming, J. A.; Forest, T. A.; Garillon, B.; Garçon, M.; Ghandilyan, Y.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Goetz, J. T.; Golovatch, E.; Gothe, R. W.; Griffioen, K. A.; Guegan, B.; Guidal, M.; Hakobyan, H.; Hanretty, C.; Hattawy, M.; Holtrop, M.; Hughes, S. M.; Hyde, C. E.; Ilieva, Y.; Ireland, D. G.; Jiang, H.; Jo, H. S.; Joo, K.; Keller, D.; Khandaker, M.; Kim, A.; Kim, W.; Koirala, S.; Kubarovsky, V.; Kuleshov, S. V.; Lenisa, P.; Levine, W. I.; Livingston, K.; Lu, H. Y.; MacGregor, I. J. D.; Mayer, M.; McKinnon, B.; Meyer, C. A.; Mirazita, M.; Mokeev, V.; Montgomery, R. A.; Moody, C. I.; Moutarde, H.; Movsisyan, A.; Camacho, C. Munoz; Nadel-Turonski, P.; Niccolai, S.; Niculescu, G.; Niculescu, I.; Osipenko, M.; Ostrovidov, A. I.; Pappalardo, L. L.; Paremuzyan, R.; Peng, P.; Phelps, W.; Pisano, S.; Pogorelko, O.; Pozdniakov, S.; Price, J. W.; Protopopescu, D.; Puckett, A. J. R.; Raue, B. A.; Rimal, D.; Ripani, M.; Rizzo, A.; Rosner, G.; Roy, P.; Sabatié, F.; Saini, M. S.; Schott, D.; Schumacher, R. A.; Simonyan, A.; Sokhan, D.; Strauch, S.; Sytnik, V.; Tang, W.; Tian, Ye; Ungaro, M.; Vernarsky, B.; Vlassov, A. V.; Voskanyan, H.; Voutier, E.; Walford, N. K.; Watts, D. P.; Wei, X.; Weinstein, L. B.; Wood, M. H.; Zachariou, N.; Zhang, J.; Zhao, Z. W.; Zonta, I.; CLAS Collaboration
2014-10-01
We measured the ratios of electroproduction cross sections from a proton target for three exclusive meson-baryon final states: ΛK+, pπ0, and nπ+, with the CLAS detector at Jefferson Lab. Using a simple model of quark hadronization, we extract qq ¯ creation probabilities for the first time in exclusive two-body production, in which only a single qq ¯ pair is created. We observe a sizable suppression of strange quark-antiquark pairs compared to nonstrange pairs, similar to that seen in high-energy production.
Strangeness suppression of qq creation observed in exclusive reactions.
Mestayer, M D; Park, K; Adhikari, K P; Aghasyan, M; Pereira, S Anefalos; Ball, J; Battaglieri, M; Batourine, V; Bedlinskiy, I; Biselli, A S; Boiarinov, S; Briscoe, W J; Brooks, W K; Burkert, V D; Carman, D S; Celentano, A; Chandavar, S; Charles, G; Colaneri, L; Cole, P L; Contalbrigo, M; Cortes, O; Crede, V; D'Angelo, A; Dashyan, N; De Vita, R; Deur, A; Djalali, C; Doughty, D; Dupre, R; El Alaoui, A; El Fassi, L; Elouadrhiri, L; Eugenio, P; Fedotov, G; Fleming, J A; Forest, T A; Garillon, B; Garçon, M; Ghandilyan, Y; Gilfoyle, G P; Giovanetti, K L; Girod, F X; Goetz, J T; Golovatch, E; Gothe, R W; Griffioen, K A; Guegan, B; Guidal, M; Hakobyan, H; Hanretty, C; Hattawy, M; Holtrop, M; Hughes, S M; Hyde, C E; Ilieva, Y; Ireland, D G; Jiang, H; Jo, H S; Joo, K; Keller, D; Khandaker, M; Kim, A; Kim, W; Koirala, S; Kubarovsky, V; Kuleshov, S V; Lenisa, P; Levine, W I; Livingston, K; Lu, H Y; MacGregor, I J D; Mayer, M; McKinnon, B; Meyer, C A; Mirazita, M; Mokeev, V; Montgomery, R A; Moody, C I; Moutarde, H; Movsisyan, A; Camacho, C Munoz; Nadel-Turonski, P; Niccolai, S; Niculescu, G; Niculescu, I; Osipenko, M; Ostrovidov, A I; Pappalardo, L L; Paremuzyan, R; Peng, P; Phelps, W; Pisano, S; Pogorelko, O; Pozdniakov, S; Price, J W; Protopopescu, D; Puckett, A J R; Raue, B A; Rimal, D; Ripani, M; Rizzo, A; Rosner, G; Roy, P; Sabatié, F; Saini, M S; Schott, D; Schumacher, R A; Simonyan, A; Sokhan, D; Strauch, S; Sytnik, V; Tang, W; Tian, Ye; Ungaro, M; Vernarsky, B; Vlassov, A V; Voskanyan, H; Voutier, E; Walford, N K; Watts, D P; Wei, X; Weinstein, L B; Wood, M H; Zachariou, N; Zhang, J; Zhao, Z W; Zonta, I
2014-10-10
We measured the ratios of electroproduction cross sections from a proton target for three exclusive meson-baryon final states: ΛK(+), pπ(0), and nπ(+), with the CLAS detector at Jefferson Lab. Using a simple model of quark hadronization, we extract qq creation probabilities for the first time in exclusive two-body production, in which only a single qq pair is created. We observe a sizable suppression of strange quark-antiquark pairs compared to nonstrange pairs, similar to that seen in high-energy production.
Irreducible complexity of iterated symmetric bimodal maps
Directory of Open Access Journals (Sweden)
J. P. Lampreia
2005-01-01
Full Text Available We introduce a tree structure for the iterates of symmetric bimodal maps and identify a subset which we prove to be isomorphic to the family of unimodal maps. This subset is used as a second factor for a ∗-product that we define in the space of bimodal kneading sequences. Finally, we give some properties for this product and study the ∗-product induced on the associated Markov shifts.
A symmetric Roos bound for linear codes
Duursma, I.M.; Pellikaan, G.R.
2006-01-01
The van Lint–Wilson AB-method yields a short proof of the Roos bound for the minimum distance of a cyclic code. We use the AB-method to obtain a different bound for the weights of a linear code. In contrast to the Roos bound, the role of the codes A and B in our bound is symmetric. We use the bound
Symmetric voltage-controlled variable resistance
Vanelli, J. C.
1978-01-01
Feedback network makes resistance of field-effect transistor (FET) same for current flowing in either direction. It combines control voltage with source and load voltages to give symmetric current/voltage characteristics. Since circuit produces same magnitude output voltage for current flowing in either direction, it introduces no offset in presense of altering polarity signals. It is therefore ideal for sensor and effector circuits in servocontrol systems.
Resistor Networks based on Symmetrical Polytopes
Directory of Open Access Journals (Sweden)
Jeremy Moody
2015-03-01
Full Text Available This paper shows how a method developed by Van Steenwijk can be generalized to calculate the resistance between any two vertices of a symmetrical polytope all of whose edges are identical resistors. The method is applied to a number of cases that have not been studied earlier such as the Archimedean polyhedra and their duals in three dimensions, the regular polytopes in four dimensions and the hypercube in any number of dimensions.
Symmetric vs. asymmetric punishment regimes for bribery
Engel, Christoph; Goerg, Sebastian J.; Yu, Gaoneng
2012-01-01
In major legal orders such as UK, the U.S., Germany, and France, bribers and recipients face equally severe criminal sanctions. In contrast, countries like China, Russia, and Japan treat the briber more mildly. Given these differences between symmetric and asymmetric punishment regimes for bribery, one may wonder which punishment strategy is more effective in curbing corruption. For this purpose, we designed and ran a lab experiment in Bonn (Germany) and Shanghai (China) with exactly the same...
Symmetric scrolled packings of multilayered carbon nanoribbons
Savin, A. V.; Korznikova, E. A.; Lobzenko, I. P.; Baimova, Yu. A.; Dmitriev, S. V.
2016-06-01
Scrolled packings of single-layer and multilayer graphene can be used for the creation of supercapacitors, nanopumps, nanofilters, and other nanodevices. The full atomistic simulation of graphene scrolls is restricted to consideration of relatively small systems in small time intervals. To overcome this difficulty, a two-dimensional chain model making possible an efficient calculation of static and dynamic characteristics of nanoribbon scrolls with allowance for the longitudinal and bending stiffness of nanoribbons is proposed. The model is extended to the case of scrolls of multilayer graphene. Possible equilibrium states of symmetric scrolls of multilayer carbon nanotribbons rolled up so that all nanoribbons in the scroll are equivalent are found. Dependences of the number of coils, the inner and outer radii, lowest vibrational eigenfrequencies of rolled packages on the length L of nanoribbons are obtained. It is shown that the lowest vibrational eigenfrequency of a symmetric scroll decreases with a nanoribbon length proportionally to L -1. It is energetically unfavorable for too short nanoribbons to roll up, and their ground state is a stack of plane nanoribbons. With an increasing number k of layers, the nanoribbon length L necessary for creation of symmetric scrolls increases. For a sufficiently small number of layers k and a sufficiently large nanoribbon length L, the scrolled packing has the lowest energy as compared to that of stack of plane nanoribbons and folded structures. The results can be used for development of nanomaterials and nanodevices on the basis of graphene scrolled packings.
Is the Universe matter-antimatter symmetric
International Nuclear Information System (INIS)
Alfven, H.
1976-09-01
According to the symmetric cosmology there should be antimatter regions in space which are equally as large as the matter regions. The regions of different kind are separated by Leidenfrost layers, which may be very thin and not observable from a distance. This view has met resistance which in part is based on the old view that the dilute interstellar and intergalactic medium is more or less homogeneous. However, through space research in the magnetosphere and interplanetary space we know that thin layers, dividing space into regions of different magnetisation, exist and based on this it is concluded that space in general has a cellular structure. This result may break down the psychological resistance to the symmetric theory. The possibility that every second star in our galaxy consists of antimatter is discussed, and it is shown that this view is not in conflict with any observations. As most stars are likely to be surrounded by solar systems of a structure like our own, it is concluded that collisions between comets and antistars (or anticomets and stars) would be rather frequent. Such collisions would result in phenomena of the same type as the observed cosmic γ-ray bursts. Another support for the symmetric cosmology is the continuous X-ray background radiation. Also many of the observed large energy releases in cosmos are likely to be due to annihilation
Problems of Chernobyl exclusion zone
International Nuclear Information System (INIS)
1994-01-01
The collection reflects the results of researches and test-design activities in the exclusion area of the Chernobyl NPP directed to elaborate the equipment and devices for scientific researches and elimination of the accident after effects at the Chernobyl NPP and to study composition and structure of solid-phase bearers of the activity in the soil of the exclusion area, form transformation of decay products, radionuclide composition of the fuel precipitation in the nearest zone of the Chernobyl NPP. Special attention is paid to medical-biological problems of the accident after effects influence on flora, fauna and human health, labour conditions and sick rate of people working in the exclusion area
Unified Treatment of a Class of Spherically Symmetric Potentials: Quasi-Exact Solution
International Nuclear Information System (INIS)
Baradaran, M.; Panahi, H.
2016-01-01
We investigate the Schrödinger equation for a class of spherically symmetric potentials in a simple and unified manner using the Lie algebraic approach within the framework of quasi-exact solvability. We illustrate that all models give rise to the same basic differential equation, which is expressible as an element of the universal enveloping algebra of sl(2). Then, we obtain the general exact solutions of the problem by employing the representation theory of sl(2) Lie algebra.
On the harmonic starlike functions with respect to symmetric ...
African Journals Online (AJOL)
In the present paper, we introduce the notions of functions harmonic starlike with respect to symmetric, conjugate and symmetric conjugate points. Such results as coefficient inequalities and structural formulae for these function classes are proved. Keywords: Harmonic functions, harmonic starlike functions, symmetric points, ...
Problems of Chernobyl exclusion zone
International Nuclear Information System (INIS)
1996-01-01
The collection comprises the results of researches and design activity in the ChNPP exclusion zone with the aim to develop technology, equipment and instruments for RAW management and accident clean-up, studying of the composition and structure of the activity solid bearers in the soil of the exclusion zone and transformation of the radionuclides in the nearest zone of ChNPP. Much attention is paid to medical and biological problems of the accident influence on the flora, fauna and people's health labour conditions and incidence of the people involved
Problems of Chornobyl Exclusion Zone
International Nuclear Information System (INIS)
Kashparov, V.A.
2009-01-01
The collection comprises the results of researches and design activity in the ChNPP exclusion zone with the aim to develop technology, equipment and instruments for RAW management and accident clean-up, studying of the composition and structure of the activity solid bearers in the soil of the exclusion zone and transformation of the radionuclides in the nearest zone of ChNPP. Much attention is paid to medical and biological problems of the accident influence on the flora, fauna and people's health, labour conditions and incidence of the people involved.
Exclusion statistics and integrable models
International Nuclear Information System (INIS)
Mashkevich, S.
1998-01-01
The definition of exclusion statistics that was given by Haldane admits a 'statistical interaction' between distinguishable particles (multispecies statistics). For such statistics, thermodynamic quantities can be evaluated exactly; explicit expressions are presented here for cluster coefficients. Furthermore, single-species exclusion statistics is realized in one-dimensional integrable models of the Calogero-Sutherland type. The interesting questions of generalizing this correspondence to the higher-dimensional and the multispecies cases remain essentially open; however, our results provide some hints as to searches for the models in question
Dual formulation of covariant nonlinear duality-symmetric action of kappa-symmetric D3-brane
Vanichchapongjaroen, Pichet
2018-02-01
We study the construction of covariant nonlinear duality-symmetric actions in dual formulation. Essentially, the construction is the PST-covariantisation and nonlinearisation of Zwanziger action. The covariantisation made use of three auxiliary scalar fields. Apart from these, the construction proceed in a similar way to that of the standard formulation. For example, the theories can be extended to include interactions with external fields, and that the theories possess two local PST symmetries. We then explicitly demonstrate the construction of covariant nonlinear duality-symmetric actions in dual formulation of DBI theory, and D3-brane. For each of these theories, the twisted selfduality condition obtained from duality-symmetric actions are explicitly shown to match with the duality relation between field strength and its dual from the one-potential actions. Their on-shell actions between the duality-symmetric and the one-potential versions are also shown to match. We also explicitly prove kappa-symmetry of the covariant nonlinear duality-symmetric D3-brane action in dual formulation.
2017-01-01
top rotor superimposes an effective correlation time, τe, onto a symmetric top rotor to account for internal motion. 2. THEORY The purpose...specifically describe how simple 13C relaxation theory is used to describe quantitatively simple molecular 3 motions. More-detailed accounts ...of nuclear magnetic relaxation can be found in a number of basic textbooks (i.e., Farrar and Becker, 1971; Fukushima and Roeder, 1981; Harris, 1986
A simple and realistic triton wave function
International Nuclear Information System (INIS)
Lomnitz-Adler, J.; Pandharipande, V.R.
1980-01-01
We propose a simple triton wave function that consists of a product of three correlation operators operating on a three-body spin-isospin state. This wave function is formally similar to that used in the recent variational theories of nuclear matter, the main difference being in the long-range behavior of the correlation operators. Variational calculations are carried out with the Reid potential, using this wave function in the so-called 'symmetrized product' and 'independent pair' forms. The triton energy and density distributions obtained with the symmetrized product wave function agree with those obtained in Faddeev and other variational calculations using harmonic oscillator states. The proposed wave function and calculational methods can be easily generalized to treat the four-nucleon α-particle. (orig.)
Exclusive processes in quantum chromodynamics
International Nuclear Information System (INIS)
Brodsky, S.J.; Lepage, G.P.
1981-06-01
Large momentum transfer exclusive processes and the short distance structure of hadronic wave functions can be systematically analyzed within the context of perturbative QCD. Predictions for meson form factors, two-photon processes γγ → M anti M, hadronic decays of heavy quark systems, and a number of other related QCD phenomena are reviewed
Exclusive meson production at COMPASS
Pochodzalla, Josef; Moinester, Murray; Piller, Gunther; Sandacz, Andrzej; Vanderhaeghen, Marc; Pochodzalla, Josef; Mankiewicz, Lech; Moinester, Murray; Piller, Gunther; Sandacz, Andrzej; Vanderhaeghen, Marc
1999-01-01
We explore the feasibility to study exclusive meson production (EMP) in hard muon-proton scattering at the COMPASS experiment. These measurements constrain the off-forward parton distributions (OFPD's) of the proton, which are related to the quark orbital contribution to the proton spin.
A simple finite element method for linear hyperbolic problems
International Nuclear Information System (INIS)
Mu, Lin; Ye, Xiu
2017-01-01
Here, we introduce a simple finite element method for solving first order hyperbolic equations with easy implementation and analysis. Our new method, with a symmetric, positive definite system, is designed to use discontinuous approximations on finite element partitions consisting of arbitrary shape of polygons/polyhedra. Error estimate is established. Extensive numerical examples are tested that demonstrate the robustness and flexibility of the method.
Dijet rates with symmetric Et cuts
International Nuclear Information System (INIS)
Banfi, Andrea; Dasgupta, Mrinal
2004-01-01
We consider dijet production in the region where symmetric cuts on the transverse energy, E t , are applied to the jets. In this region next-to-leading order calculations are unreliable and an all-order resummation of soft gluon effects is needed, which we carry out. Although, for illustrative purposes, we choose dijets produced in deep inelastic scattering, our general ideas apply additionally to dijets produced in photoproduction or gamma-gamma processes and should be relevant also to the study of prompt di-photon E t spectra in association with a recoiling jet, in hadron-hadron processes. (author)
Covariant, chirally symmetric, confining model of mesons
International Nuclear Information System (INIS)
Gross, F.; Milana, J.
1991-01-01
We introduce a new model of mesons as quark-antiquark bound states. The model is covariant, confining, and chirally symmetric. Our equations give an analytic solution for a zero-mass pseudoscalar bound state in the case of exact chiral symmetry, and also reduce to the familiar, highly successful nonrelativistic linear potential models in the limit of heavy-quark mass and lightly bound systems. In this fashion we are constructing a unified description of all the mesons from the π through the Υ. Numerical solutions for other cases are also presented
Symmetric Logic Synthesis with Phase Assignment
Benschop, N. F.
2001-01-01
Decomposition of any Boolean Function BF_n of n binary inputs into an optimal inverter coupled network of Symmetric Boolean functions SF_k (k \\leq n) is described. Each SF component is implemented by Threshold Logic Cells, forming a complete and compact T-Cell Library. Optimal phase assignment of input polarities maximizes local symmetries. The "rank spectrum" is a new BF_n description independent of input ordering, obtained by mapping its minterms onto an othogonal n \\times n grid of (transi...
Elastic energy for reflection-symmetric topologies
International Nuclear Information System (INIS)
Majumdar, A; Robbins, J M; Zyskin, M
2006-01-01
Nematic liquid crystals in a polyhedral domain, a prototype for bistable displays, may be described by a unit-vector field subject to tangent boundary conditions. Here we consider the case of a rectangular prism. For configurations with reflection-symmetric topologies, we derive a new lower bound for the one-constant elastic energy. For certain topologies, called conformal and anticonformal, the lower bound agrees with a previous result. For the remaining topologies, called nonconformal, the new bound is an improvement. For nonconformal topologies we derive an upper bound, which differs from the lower bound by a factor depending only on the aspect ratios of the prism
Nanotribology of Symmetric and Asymmetric Liquid Lubricants
Directory of Open Access Journals (Sweden)
Shinji Yamada
2010-03-01
Full Text Available When liquid molecules are confined in a narrow gap between smooth surfaces, their dynamic properties are completely different from those of the bulk. The molecular motions are highly restricted and the system exhibits solid-like responses when sheared slowly. This solidification behavior is very dependent on the molecular geometry (shape of liquids because the solidification is induced by the packing of molecules into ordered structures in confinement. This paper reviews the measurements of confined structures and friction of symmetric and asymmetric liquid lubricants using the surface forces apparatus. The results show subtle and complex friction mechanisms at the molecular scale.
Unary self-verifying symmetric difference automata
CSIR Research Space (South Africa)
Marais, Laurette
2016-07-01
Full Text Available stream_source_info Marais_2016_ABSTRACT.pdf.txt stream_content_type text/plain stream_size 796 Content-Encoding ISO-8859-1 stream_name Marais_2016_ABSTRACT.pdf.txt Content-Type text/plain; charset=ISO-8859-1 18th... International Workshop on Descriptional Complexity of Formal Systems, 5 - 8 July 2016, Bucharest, Romania Unary self-verifying symmetric difference automata Laurette Marais1,2 and Lynette van Zijl1(B) 1 Department of Computer Science, Stellenbosch...
Characterisation of an AGATA symmetric prototype detector
International Nuclear Information System (INIS)
Nelson, L.; Dimmock, M.R.; Boston, A.J.; Boston, H.C.; Cresswell, J.R.; Nolan, P.J.; Lazarus, I.; Simpson, J.; Medina, P.; Santos, C.; Parisel, C.
2007-01-01
The Advanced GAmma Tracking Array (AGATA) symmetric prototype detector has been tested at University of Liverpool. A 137 Ce source, collimated to a 2 mm diameter, was scanned across the front face of the detector and data were acquired utilising digital electronics. Pulse shapes from a selection of well-defined photon interaction positions have been analysed to investigate the position sensitivity of the detector. Furthermore, the application of the electric field simulation software, Multi Geometry Simulation (MGS) to generate theoretical pulse shapes for AGATA detectors has been presented
How Symmetrical Assumptions Advance Strategic Management Research
DEFF Research Database (Denmark)
Foss, Nicolai Juul; Hallberg, Hallberg
2014-01-01
We develop the case for symmetrical assumptions in strategic management theory. Assumptional symmetry obtains when assumptions made about certain actors and their interactions in one of the application domains of a theory are also made about this set of actors and their interactions in other...... application domains of the theory. We argue that assumptional symmetry leads to theoretical advancement by promoting the development of theory with greater falsifiability and stronger ontological grounding. Thus, strategic management theory may be advanced by systematically searching for asymmetrical...
Characterisation of an AGATA symmetric prototype detector
Energy Technology Data Exchange (ETDEWEB)
Nelson, L. [Oliver Lodge Laboratory, University of Liverpool, Oxford Street, Liverpool L69 7ZE (United Kingdom)]. E-mail: ln@ns.ph.liv.ac.uk; Dimmock, M.R. [Oliver Lodge Laboratory, University of Liverpool, Oxford Street, Liverpool L69 7ZE (United Kingdom)]. E-mail: mrd@ns.ph.liv.ac.uk; Boston, A.J. [Oliver Lodge Laboratory, University of Liverpool, Oxford Street, Liverpool L69 7ZE (United Kingdom)]. E-mail: ajb@ns.ph.liv.ac.uk; Boston, H.C. [Oliver Lodge Laboratory, University of Liverpool, Oxford Street, Liverpool L69 7ZE (United Kingdom); Cresswell, J.R. [Oliver Lodge Laboratory, University of Liverpool, Oxford Street, Liverpool L69 7ZE (United Kingdom); Nolan, P.J. [Oliver Lodge Laboratory, University of Liverpool, Oxford Street, Liverpool L69 7ZE (United Kingdom); Lazarus, I. [CCLRC Daresbury Laboratory, Daresbury, Warrington WA4 4AD (United Kingdom); Simpson, J. [CCLRC Daresbury Laboratory, Daresbury, Warrington WA4 4AD (United Kingdom); Medina, P. [Institut de Recherches Subatomiques, Strasbourg BP28 67037 (France); Santos, C. [Institut de Recherches Subatomiques, Strasbourg BP28 67037 (France); Parisel, C. [Institut de Recherches Subatomiques, Strasbourg BP28 67037 (France)
2007-04-01
The Advanced GAmma Tracking Array (AGATA) symmetric prototype detector has been tested at University of Liverpool. A {sup 137}Ce source, collimated to a 2 mm diameter, was scanned across the front face of the detector and data were acquired utilising digital electronics. Pulse shapes from a selection of well-defined photon interaction positions have been analysed to investigate the position sensitivity of the detector. Furthermore, the application of the electric field simulation software, Multi Geometry Simulation (MGS) to generate theoretical pulse shapes for AGATA detectors has been presented.
Soft theorems for shift-symmetric cosmologies
Finelli, Bernardo; Goon, Garrett; Pajer, Enrico; Santoni, Luca
2018-03-01
We derive soft theorems for single-clock cosmologies that enjoy a shift symmetry. These so-called consistency conditions arise from a combination of a large diffeomorphism and the internal shift symmetry and fix the squeezed limit of all correlators with a soft scalar mode. As an application, we show that our results reproduce the squeezed bispectrum for ultra-slow-roll inflation, a particular shift-symmetric, nonattractor model which is known to violate Maldacena's consistency relation. Similar results have been previously obtained by Mooij and Palma using background-wave methods. Our results shed new light on the infrared structure of single-clock cosmological spacetimes.
Pion condensation in symmetric nuclear matter
International Nuclear Information System (INIS)
Shamsunnahar, T.; Saha, S.; Kabir, K.; Nath, L.M.
1991-01-01
We have investigated the possibility of pion condensation in symmetric nuclear matter using a model of pion-nucleon interaction based essentially on chiral SU(2) x SU(2) symmetry. We have found that pion condensation is not possible for any finite value of the density. Consequently, no critical opalescence phenomenon is likely to be seen in pion-nucleus scattering nor is it likely to be possible to explain the EMC effect in terms of an increased number of pions in the nucleus. (author)
Baryon symmetric big-bang cosmology
Energy Technology Data Exchange (ETDEWEB)
Stecker, F.W.
1978-04-01
The framework of baryon-symmetric big-bang cosmology offers the greatest potential for deducing the evolution of the universe as a consequence of physical laws and processes with the minimum number of arbitrary assumptions as to initial conditions in the big-bang. In addition, it offers the possibility of explaining the photon-baryon ratio in the universe and how galaxies and galaxy clusters are formed, and also provides the only acceptable explanation at present for the origin of the cosmic gamma ray background radiation.
Baryon symmetric big-bang cosmology
International Nuclear Information System (INIS)
Stecker, F.W.
1978-04-01
The framework of baryon-symmetric big-bang cosmology offers the greatest potential for deducing the evolution of the universe as a consequence of physical laws and processes with the minimum number of arbitrary assumptions as to initial conditions in the big-bang. In addition, it offers the possibility of explaining the photon-baryon ratio in the universe and how galaxies and galaxy clusters are formed, and also provides the only acceptable explanation at present for the origin of the cosmic gamma ray background radiation
... Solitary Kidney Your Kidneys & How They Work Simple Kidney Cysts What are simple kidney cysts? Simple kidney cysts are abnormal, fluid-filled ... that form in the kidneys. What are the kidneys and what do they do? The kidneys are ...
On the Relations between the Attacks on Symmetric Homomorphic Encryption over the Residue Ring
Directory of Open Access Journals (Sweden)
Alina V. Trepacheva
2017-06-01
Full Text Available The paper considers the security of symmetric homomorphic cryptosystems (HC over the residue ring. The main task is to establish an equivalence between ciphertexts only attack (COA and known plaintexts attack (KPA for HC. The notion of reducibility between attacks and sufficient condition of reducibility from COA to KPA are given for this purpose. The main idea is: to prove reducibility from COA to KPA we need to find a function over residue ring being efficiently computable and having a small image size comparing with the size of residue ring. The study of reducibility existence is important since it allows to understand better the security level of symmetric HC proposed in literature. A vulnerability against KPA has been already found for the majority of these HC. Thus the reducibility presence can demonstrate that cryptosystems under the study are not secure even against COA, and therefore they are totally insecure and shouldn’t be used in practice. We give an example of reducibility from COA to KPA for residue ring being a simple field. Based on this example we show an efficient COA on one symmetric HC for small field. Also we separately consider the case of residue ring composed using number n being hard-to-factor. For such n an efficient algorithm to construct an efficiently computable function with small image is unknown so far. So further work related to cryptanalysis of existing symmetric HC will be directed into study of functions properties over residue rings modulo numbers hard for factorization.
Parametric amplification and bidirectional invisibility in PT -symmetric time-Floquet systems
Koutserimpas, Theodoros T.; Alù, Andrea; Fleury, Romain
2018-01-01
Parity-time (PT )-symmetric wave devices, which exploit balanced interactions between material gain and loss, exhibit extraordinary properties, including lasing and flux-conserving scattering processes. In a seemingly different research field, periodically driven systems, also known as time-Floquet systems, have been widely studied as a relevant platform for reconfigurable active wave control and manipulation. In this article, we explore the connection between PT -symmetry and parametric time-Floquet systems. Instead of relying on material gain, we use parametric amplification by considering a time-periodic modulation of the refractive index at a frequency equal to twice the incident signal frequency. We show that the scattering from a simple parametric slab, whose dynamics follows the Mathieu equation, can be described by a PT -symmetric scattering matrix, whose PT -breaking threshold corresponds to the Mathieu instability threshold. By combining different parametric slabs modulated out of phase, we create PT -symmetric time-Floquet systems that feature exceptional scattering properties, such as coherent perfect absorption (CPA)-laser operation and bidirectional invisibility. These bidirectional properties, rare for regular PT -symmetric systems, are related to a compensation of parametric amplification due to multiple scattering between two parametric systems modulated with a phase difference.
Investigating the exclusive protoproduction of dileptons at high energies
International Nuclear Information System (INIS)
Machado, Magno V. T.
2008-01-01
Using the high energy color dipole approach, we study the exclusive photoproduction of lepton pairs γN→γ*(→l + l - )N (with N=p, A). We use simple models for the elementary dipole-hadron scattering amplitude that captures main features of the dependence on atomic number A, on energy and on momentum transfer t. This investigation is complementary to conventional partonic description of timelike Compton scattering, which considers quark handbag diagrams at leading order in α s and simple models of the relevant generalized parton distributions. These calculations are input in electromagnetic interactions in pp and AA collisions to measured at the LHC.
The exclusion problem in seasonally forced epidemiological systems.
Greenman, J V; Adams, B
2015-02-21
The pathogen exclusion problem is the problem of finding control measures that will exclude a pathogen from an ecological system or, if the system is already disease-free, maintain it in that state. To solve this problem we work within a holistic control theory framework which is consistent with conventional theory for simple systems (where there is no external forcing and constant controls) and seamlessly generalises to complex systems that are subject to multiple component seasonal forcing and targeted variable controls. We develop, customise and integrate a range of numerical and algebraic procedures that provide a coherent methodology powerful enough to solve the exclusion problem in the general case. An important aspect of our solution procedure is its two-stage structure which reveals the epidemiological consequences of the controls used for exclusion. This information augments technical and economic considerations in the design of an acceptable exclusion strategy. Our methodology is used in two examples to show how time-varying controls can exploit the interference and reinforcement created by the external and internal lag structure and encourage the system to 'take over' some of the exclusion effort. On-off control switching, resonant amplification, optimality and controllability are important issues that emerge in the discussion. Copyright © 2014 Elsevier Ltd. All rights reserved.
Problems of Chernobyl exclusion zone
International Nuclear Information System (INIS)
1996-01-01
The collection comprises the results of researches and design activity in the ChNPP exclusion zone with the aim to develop technology, equipment and instruments for RAW management and accident clean-up, studying of the composition and structure of the activity solid bearers in the soil of the exclusion zone and transformation of the radionuclides in the nearest zone of ChNPP. Much attention is paid to medical and biological problems of the accident influence on the flora, fauna and people's health, labour conditions and incidence of the people involved. The collection comprises the information for scientists, experts, postgraduates and students in gaged in ecology, radioecology, nuclear engineering, radiology, radiochemistry and radiobiology
Electroweak Baryogenesis in R-symmetric Supersymmetry
Energy Technology Data Exchange (ETDEWEB)
Fok, R.; Kribs, Graham D.; Martin, Adam; Tsai, Yuhsin
2013-03-01
We demonstrate that electroweak baryogenesis can occur in a supersymmetric model with an exact R-symmetry. The minimal R-symmetric supersymmetric model contains chiral superfields in the adjoint representation, giving Dirac gaugino masses, and an additional set of "R-partner" Higgs superfields, giving R-symmetric \\mu-terms. New superpotential couplings between the adjoints and the Higgs fields can simultaneously increase the strength of the electroweak phase transition and provide additional tree-level contributions to the lightest Higgs mass. Notably, no light stop is present in this framework, and in fact, we require both stops to be above a few TeV to provide sufficient radiative corrections to the lightest Higgs mass to bring it up to 125 GeV. Large CP-violating phases in the gaugino/higgsino sector allow us to match the baryon asymmetry of the Universe with no constraints from electric dipole moments due to R-symmetry. We briefly discuss some of the more interesting phenomenology, particularly of the of the lightest CP-odd scalar.
Exclusive photoreactions on light nuclei
International Nuclear Information System (INIS)
Maruyama, K.
1989-08-01
The mechanism of photon absorption on light nuclei in the Δ-resonance region is discussed. The present status of experimental results is briefly summarized. A recent data from 1.3-GeV Tokyo ES using a π sr spectrometer is introduced. Exclusive measurements of the photodisintegration of 3 He and 4 He may be a clear way to identify 2N, 3N and 4N absorptions. (author)
Gender, Marginalisation and Social Exclusion
DEFF Research Database (Denmark)
D. Munk, Martin
The paper is focused on the fact that marginalisation and social exclusion are gender-related in the EU. Even when boys and girls experience the same kinds of strain and social inheritance, they react socially different. Likewise women and men are marginalised in different ways. The differing...... access to the five ressources: cultural, financial, mental, social and powerrelated resources is highlighted. It is demonstrated how gender involves living in different realities, and requires different solutions to create equal possibilities....
Directory of Open Access Journals (Sweden)
Trond S. Ingebrigtsen
2012-03-01
Full Text Available This paper is an attempt to identify the real essence of simplicity of liquids in John Locke’s understanding of the term. Simple liquids are traditionally defined as many-body systems of classical particles interacting via radially symmetric pair potentials. We suggest that a simple liquid should be defined instead by the property of having strong correlations between virial and potential-energy equilibrium fluctuations in the NVT ensemble. There is considerable overlap between the two definitions, but also some notable differences. For instance, in the new definition simplicity is not a direct property of the intermolecular potential because a liquid is usually only strongly correlating in part of its phase diagram. Moreover, not all simple liquids are atomic (i.e., with radially symmetric pair potentials and not all atomic liquids are simple. The main part of the paper motivates the new definition of liquid simplicity by presenting evidence that a liquid is strongly correlating if and only if its intermolecular interactions may be ignored beyond the first coordination shell (FCS. This is demonstrated by NVT simulations of the structure and dynamics of several atomic and three molecular model liquids with a shifted-forces cutoff placed at the first minimum of the radial distribution function. The liquids studied are inverse power-law systems (r^{-n} pair potentials with n=18,6,4, Lennard-Jones (LJ models (the standard LJ model, two generalized Kob-Andersen binary LJ mixtures, and the Wahnstrom binary LJ mixture, the Buckingham model, the Dzugutov model, the LJ Gaussian model, the Gaussian core model, the Hansen-McDonald molten salt model, the Lewis-Wahnstrom ortho-terphenyl model, the asymmetric dumbbell model, and the single-point charge water model. The final part of the paper summarizes properties of strongly correlating liquids, emphasizing that these are simpler than liquids in general. Simple liquids, as defined here, may be
Rotor current transient analysis of DFIG-based wind turbines during symmetrical voltage faults
International Nuclear Information System (INIS)
Ling, Yu; Cai, Xu; Wang, Ningbo
2013-01-01
Highlights: • We theoretically analyze the rotor fault current of DFIG based on space vector. • The presented analysis is simple, easy to understand. • The analysis highlights the accuracy of the expression of the rotor fault currents. • The expression can be widely used to analyze the different levels of voltage symmetrical fault. • Simulation results show the accuracy of the expression of the rotor currents. - Abstract: The impact of grid voltage fault on doubly fed induction generators (DFIGs), especially rotor currents, has received much attention. So, in this paper, the rotor currents of based-DFIG wind turbines are considered in a generalized way, which can be widely used to analyze the cases under different levels of voltage symmetrical faults. A direct method based on space vector is proposed to obtain an accurate expression of rotor currents as a function of time for symmetrical voltage faults in the power system. The presented theoretical analysis is simple and easy to understand and especially highlights the accuracy of the expression. Finally, the comparable simulations evaluate this analysis and show that the expression of the rotor currents is sufficient to calculate the maximum fault current, DC and AC components, and especially helps to understand the causes of the problem and as a result, contributes to adapt reasonable approaches to enhance the fault ride through (FRT) capability of DFIG wind turbines during a voltage fault
A simple fluxgate magnetometer using amorphous alloys
International Nuclear Information System (INIS)
Ghatak, S.K.; Mitra, A.
1992-01-01
A simple fluxgate magnetometer is developed using low magnetostrictive ferromagnetic amorphous alloy acting as a sensing element. It uses the fact that the magnetization of sensing element symmetrically magnetized by a sinusoidal field contains even harmonic components in presence of dc signal field H and the amplitude of the second harmonic component of magnetization is proportional to H. The sensitivity and linearity of the magnetometer with signal field are studied for parallel configuration and the field ranging from 10 nT to 10 μT can be measured. The functioning of the magnetometer is demonstrated by studying the shielding and flux-trapping phenomena in high-Tc superconductor. (orig.)
Geometric inequalities for axially symmetric black holes
International Nuclear Information System (INIS)
Dain, Sergio
2012-01-01
A geometric inequality in general relativity relates quantities that have both a physical interpretation and a geometrical definition. It is well known that the parameters that characterize the Kerr-Newman black hole satisfy several important geometric inequalities. Remarkably enough, some of these inequalities also hold for dynamical black holes. This kind of inequalities play an important role in the characterization of the gravitational collapse; they are closely related with the cosmic censorship conjecture. Axially symmetric black holes are the natural candidates to study these inequalities because the quasi-local angular momentum is well defined for them. We review recent results in this subject and we also describe the main ideas behind the proofs. Finally, a list of relevant open problems is presented. (topical review)
A symmetric bipolar nebula around MWC 922.
Tuthill, P G; Lloyd, J P
2007-04-13
We report regular and symmetric structure around dust-enshrouded Be star MWC 922 obtained with infrared imaging. Biconical lobes that appear nearly square in aspect, forming this "Red Square" nebula, are crossed by a series of rungs that terminate in bright knots or "vortices," and an equatorial dark band crossing the core delimits twin hyperbolic arcs. The intricate yet cleanly constructed forms that comprise the skeleton of the object argue for minimal perturbation from global turbulent or chaotic effects. We also report the presence of a linear comb structure, which may arise from optically projected shadows of a periodic feature in the inner regions, such as corrugations in the rim of a circumstellar disk. The sequence of nested polar rings draws comparison with the triple-ring system seen around the only naked-eye supernova in recent history: SN1987A.
Minimal Left-Right Symmetric Dark Matter.
Heeck, Julian; Patra, Sudhanwa
2015-09-18
We show that left-right symmetric models can easily accommodate stable TeV-scale dark matter particles without the need for an ad hoc stabilizing symmetry. The stability of a newly introduced multiplet either arises accidentally as in the minimal dark matter framework or comes courtesy of the remaining unbroken Z_{2} subgroup of B-L. Only one new parameter is introduced: the mass of the new multiplet. As minimal examples, we study left-right fermion triplets and quintuplets and show that they can form viable two-component dark matter. This approach is, in particular, valid for SU(2)×SU(2)×U(1) models that explain the recent diboson excess at ATLAS in terms of a new charged gauge boson of mass 2 TeV.
Design and Analysis of Symmetric Primitives
DEFF Research Database (Denmark)
Lauridsen, Martin Mehl
. In the second part, we delve into the matter of the various aspects of designing a symmetric cryptographic primitive. We start by considering generalizations of the widely acclaimed Advanced Encryption Standard (AES) block cipher. In particular, our focus is on a component operation in the cipher which permutes...... analyze and implement modes recommended by the National Institute of Standards and Technology (NIST), as well as authenticated encryption modes from the CAESAR competition, when instantiated with the AES. The data processed in our benchmarking has sizes representative to that of typical Internet traffic...... linear cryptanalysis. We apply this model to the standardized block cipher PRESENT. Finally, we present very generic attacks on two authenticated encryption schemes, AVALANCHE and RBS, by pointing out severe design flaws that can be leveraged to fully recover the secret key with very low complexity...
Quasiaxially symmetric stellarators with three field periods
International Nuclear Information System (INIS)
Garabedian, P.; Ku, L.
1999-01-01
Compact hybrid configurations with two field periods have been studied recently as candidates for a proof of principle experiment at the Princeton Plasma Physics Laboratory. This project has led us to the discovery of a family of quasiaxially symmetric stellarators with three field periods that have significant advantages, although their aspect ratios are a little larger. They have reversed shear and perform better in a local analysis of ballooning modes. Nonlinear equilibrium and stability calculations predict that the average beta limit will be at least as high as 4% if the bootstrap current turns out to be as big as that expected in comparable tokamaks. The concept relies on a combination of helical fields and bootstrap current to achieve adequate rotational transform at low aspect ratio. copyright 1999 American Institute of Physics
Primordial two-component maximally symmetric inflation
Enqvist, K.; Nanopoulos, D. V.; Quirós, M.; Kounnas, C.
1985-12-01
We propose a two-component inflation model, based on maximally symmetric supergravity, where the scales of reheating and the inflation potential at the origin are decoupled. This is possible because of the second-order phase transition from SU(5) to SU(3)×SU(2)×U(1) that takes place when φ≅φcinflation at the global minimum, and leads to a reheating temperature TR≅(1015-1016) GeV. This makes it possible to generate baryon asymmetry in the conventional way without any conflict with experimental data on proton lifetime. The mass of the gravitinos is m3/2≅1012 GeV, thus avoiding the gravitino problem. Monopoles are diluted by residual inflation in the broken phase below the cosmological bounds if φcUSA.
Lovelock black holes with maximally symmetric horizons
Energy Technology Data Exchange (ETDEWEB)
Maeda, Hideki; Willison, Steven; Ray, Sourya, E-mail: hideki@cecs.cl, E-mail: willison@cecs.cl, E-mail: ray@cecs.cl [Centro de Estudios CientIficos (CECs), Casilla 1469, Valdivia (Chile)
2011-08-21
We investigate some properties of n( {>=} 4)-dimensional spacetimes having symmetries corresponding to the isometries of an (n - 2)-dimensional maximally symmetric space in Lovelock gravity under the null or dominant energy condition. The well-posedness of the generalized Misner-Sharp quasi-local mass proposed in the past study is shown. Using this quasi-local mass, we clarify the basic properties of the dynamical black holes defined by a future outer trapping horizon under certain assumptions on the Lovelock coupling constants. The C{sup 2} vacuum solutions are classified into four types: (i) Schwarzschild-Tangherlini-type solution; (ii) Nariai-type solution; (iii) special degenerate vacuum solution; and (iv) exceptional vacuum solution. The conditions for the realization of the last two solutions are clarified. The Schwarzschild-Tangherlini-type solution is studied in detail. We prove the first law of black-hole thermodynamics and present the expressions for the heat capacity and the free energy.
Polyhomogeneous expansions from time symmetric initial data
Gasperín, E.; Valiente Kroon, J. A.
2017-10-01
We make use of Friedrich’s construction of the cylinder at spatial infinity to relate the logarithmic terms appearing in asymptotic expansions of components of the Weyl tensor to the freely specifiable parts of time symmetric initial data sets for the Einstein field equations. Our analysis is based on the assumption that a particular type of formal expansions near the cylinder at spatial infinity corresponds to the leading terms of actual solutions to the Einstein field equations. In particular, we show that if the Bach tensor of the initial conformal metric does not vanish at the point at infinity then the most singular component of the Weyl tensor decays near null infinity as O(\\tilde{r}-3\\ln \\tilde{r}) so that spacetime will not peel. We also provide necessary conditions on the initial data which should lead to a peeling spacetime. Finally, we show how to construct global spacetimes which are candidates for non-peeling (polyhomogeneous) asymptotics.
From Symmetric Glycerol Derivatives to Dissymmetric Chlorohydrins
Directory of Open Access Journals (Sweden)
Gemma Villorbina
2011-03-01
Full Text Available The anticipated worldwide increase in biodiesel production will result in an accumulation of glycerol for which there are insufficient conventional uses. The surplus of this by-product has increased rapidly during the last decade, prompting a search for new glycerol applications. We describe here the synthesis of dissymmetric chlorohydrin esters from symmetric 1,3-dichloro-2-propyl esters obtained from glycerol. We studied the influence of two solvents: 1,4-dioxane and 1-butanol and two bases: sodium carbonate and 1-butylimidazole, on the synthesis of dissymmetric chlorohydrin esters. In addition, we studied the influence of other bases (potassium and lithium carbonates in the reaction using 1,4-dioxane as the solvent. The highest yield was obtained using 1,4-dioxane and sodium carbonate.
Bidding behavior in a symmetric Chinese auction
Directory of Open Access Journals (Sweden)
Mauricio Benegas
2015-01-01
Full Text Available This paper purposes a symmetric all-pay auction where the bidders compete neither for an object nor the object itself but for a lottery on receive. That lottery is determined endogenously through the bids. This auction is known as chance auction or more popularly as Chinese auction. The model considers the possibility that for some bidders the optimal strategy is to bid zero and to rely on luck. It showed that bidders become less aggressive when the lottery satisfies a variational condition. It was also shown that luck factor is decisive to determine if the expected payoff in Chinese auction is bigger or smaller than expected payoff in standard all-pay auction.
Canonical quantization of static spherically symmetric geometries
International Nuclear Information System (INIS)
Christodoulakis, T; Dimakis, N; Terzis, P A; Doulis, G; Grammenos, Th; Melas, E; Spanou, A
2013-01-01
The conditional symmetries of the reduced Einstein–Hilbert action emerging from a static, spherically symmetric geometry are used as supplementary conditions on the wave function. Based on their integrability conditions, only one of the three existing symmetries can be consistently imposed, while the unique Casimir invariant, being the product of the remaining two symmetries, is calculated as the only possible second condition on the wave function. This quadratic integral of motion is identified with the reparametrization generator, as an implication of the uniqueness of the dynamical evolution, by fixing a suitable parametrization of the r-lapse function. In this parametrization, the determinant of the supermetric plays the role of the mesure. The combined Wheeler – DeWitt and linear conditional symmetry equations are analytically solved. The solutions obtained depend on the product of the two ''scale factors''
Cryptanalysis of Some Lightweight Symmetric Ciphers
DEFF Research Database (Denmark)
Abdelraheem, Mohamed Ahmed Awadelkareem Mohamed Ahmed
In recent years, the need for lightweight encryption systems has been increasing as many applications use RFID and sensor networks which have a very low computational power and thus incapable of performing standard cryptographic operations. In response to this problem, the cryptographic community...... on a variant of PRESENT with identical round keys. We propose a new attack named the Invariant Subspace Attack that was specifically mounted against the lightweight block cipher PRINTcipher. Furthermore, we mount several attacks on a recently proposed stream cipher called A2U2....... of the international standards in lightweight cryptography. This thesis aims at analyzing and evaluating the security of some the recently proposed lightweight symmetric ciphers with a focus on PRESENT-like ciphers, namely, the block cipher PRESENT and the block cipher PRINTcipher. We provide an approach to estimate...
Cosmic ray antimatter and baryon symmetric cosmology
Stecker, F. W.; Protheroe, R. J.; Kazanas, D.
1982-01-01
The relative merits and difficulties of the primary and secondary origin hypotheses for the observed cosmic-ray antiprotons, including the new low-energy measurement of Buffington, et al. We conclude that the cosmic-ray antiproton data may be evidence for antimatter galaxies and baryon symmetric cosmology. The present bar P data are consistent with a primary extragalactic component having /p=/equiv 1+/- 3.2/0.7x10 = to the -4 independent of energy. We propose that the primary extragalactic cosmic ray antiprotons are most likely from active galaxies and that expected disintegration of bar alpha/alpha ban alpha/alpha. We further predict a value for ban alpha/alpha =/equiv 10 to the -5, within range of future cosmic ray detectors.
Symmetric alignment of the nematic matrix between close penetrable colloidal particles
International Nuclear Information System (INIS)
Teixeira, P I C; Barmes, F; Cleaver, D J
2004-01-01
A simple model is proposed for the liquid crystal matrix surrounding 'soft' colloidal particles whose separation is much smaller than their radii. We use our implementation of the Onsager approximation of density-functional theory (Chrzanowska et al 2001 J. Phys.: Condens. Matter 13 4715) to calculate the structure of a nanometrically thin film of hard Gaussian overlap particles of elongations κ = 3 and 5, confined between two solid walls. The penetrability of either substrate can be tuned independently to yield symmetric or hybrid alignment. Comparison with Monte Carlo simulations of the same system (Cleaver and Teixeira 2001 Chem. Phys. Lett. 338 1, Barmes and Cleaver 2004 in preparation) reveals good agreement in the symmetric case
Reaction mechanism for the symmetric breakup of 24Mg following an interaction with 12C
International Nuclear Information System (INIS)
Gyapong, G.J.; Watson, D.L.; Catford, W.N.; Clarke, N.M.; Bennett, S.J.; Freer, M.; Fulton, B.R.; Jones, C.D.; Leddy, M.; Murgatroyd, J.T.; Rae, W.D.M.; Simmons, P.
1994-01-01
Data on the yield of the symmetric breakup of 24 Mg as a function of beam energy are presented and compared with detailed calculations of the energy dependence. The 24 Mg states seen in symmetric breakup agree with previously observed breakup states having spin and parities J π =4 + ,(6 + ),8 + . The data allow the variations of yield for indivual states to be judged, as the beam energy is varied. The variation in the yield of the 4 + states is compared in detail with calculations assuming several possible compound nuclear or direct reaction mechanisms. It is concluded that a massive ( 12 C) transfer or a simple statistical compound process are unlikely mechanisms, but that each of several other mechanisms is consistent with the data. ((orig.))
Symmetrization of the beam-beam interaction in an asymmetric collider
International Nuclear Information System (INIS)
Chin, Y.H.
1990-07-01
This paper studies the idea of symmetrizing both the lattice and the beams of an asymmetric collider, and discusses why this regime should be within the parametric reach of the design in order to credibly ensure its performance. Also examined is the effectiveness of a simple compensation method using the emittance as a free parameter and that it does not work in all cases. At present, when there are no existing asymmetric colliders, it seems prudent to design an asymmetric collider so as to be similar to a symmetric one (without relying on a particular theory of the asymmetric beam-beam interaction that has not passed tests of fidelity). Nevertheless, one must allow for the maximum possible flexibility and freedom in adjusting those parameters that affect luminosity. Such a parameter flexibility will be essential in tuning the collider to the highest luminosity
Factors influencing knowledge and practice of exclusive ...
African Journals Online (AJOL)
Factors influencing knowledge and practice of exclusive breastfeeding in Nyando ... The overall objective of this study was to determine factors influencing the ... EBF and its benefits), pre lacteal feeds and exclusive breastfeeding consistency.
Symmetric Topological Phases and Tensor Network States
Jiang, Shenghan
Classification and simulation of quantum phases are one of main themes in condensed matter physics. Quantum phases can be distinguished by their symmetrical and topological properties. The interplay between symmetry and topology in condensed matter physics often leads to exotic quantum phases and rich phase diagrams. Famous examples include quantum Hall phases, spin liquids and topological insulators. In this thesis, I present our works toward a more systematically understanding of symmetric topological quantum phases in bosonic systems. In the absence of global symmetries, gapped quantum phases are characterized by topological orders. Topological orders in 2+1D are well studied, while a systematically understanding of topological orders in 3+1D is still lacking. By studying a family of exact solvable models, we find at least some topological orders in 3+1D can be distinguished by braiding phases of loop excitations. In the presence of both global symmetries and topological orders, the interplay between them leads to new phases termed as symmetry enriched topological (SET) phases. We develop a framework to classify a large class of SET phases using tensor networks. For each tensor class, we can write down generic variational wavefunctions. We apply our method to study gapped spin liquids on the kagome lattice, which can be viewed as SET phases of on-site symmetries as well as lattice symmetries. In the absence of topological order, symmetry could protect different topological phases, which are often referred to as symmetry protected topological (SPT) phases. We present systematic constructions of tensor network wavefunctions for bosonic symmetry protected topological (SPT) phases respecting both onsite and spatial symmetries.
The radiation chemistry of symmetric aliphatic polyesters
International Nuclear Information System (INIS)
Babanalbandi, A.; Hill, D.J.T.; Pomery, P.J.; Whittaker, A.K.
1996-01-01
Full text: Naturally occurring, symmetric polyesters, including polyglycolic acid, polylactic acid and polyhydroxybutyrate, have found biomedical applications in areas as diverse as the controlled release of pharmaceuticals and the manufacture of surgical sutures. As biomedical products, the materials require sterilization by high energy radiation. This has provided the motivation for the present work. D'Alelio et al. have reported that linear, asymmetric polyesters undergo scission on irradiation, but that branched polyesters containing a methyl group in the diol segments undergo crosslinking. However, for the symmetric polyhydroxybutyrate, Carswell-Pomerantz et al. have reported that only scission occurs on radiolysis, with the evolution of CO and CO 2 as a result of the loss of ester linkages. These workers also found that G(CO + CO 2 ) was approximately equal to G(S) for this polyester. By contrast, Collett et al. have reported that G(S) = 1.26 and G(X) = 0.53 for polylactic acid, which indicates that the polymer undergoes nett crosslinking on radiolysis to form a gel. They have also reported that poly(lactic-co-glycolic acid) should form a gel on radiolysis, since G(S) = 1.66 and G(X) = 0.65 for a 1:1 copolymer composition. In the present work the radiolysis of polylactic acid and poly(lactic-co-glycolic acid) have been reinvestigated in order to resolve the differences between the work of Collett et al. and that of Carswell-Pomerantz et al. In these studies, ESR has been used to study the radicals formed, GPC has been used to investigate scission and crosslinking, GC has been used to study the small molecule volatile products and NMR spectroscopy has been used to identify and measure the new chemical structures formed in the polymers
FFLP problem with symmetric trapezoidal fuzzy numbers
Directory of Open Access Journals (Sweden)
Reza Daneshrad
2015-04-01
Full Text Available The most popular approach for solving fully fuzzy linear programming (FFLP problems is to convert them into the corresponding deterministic linear programs. Khan et al. (2013 [Khan, I. U., Ahmad, T., & Maan, N. (2013. A simplified novel technique for solving fully fuzzy linear programming problems. Journal of Optimization Theory and Applications, 159(2, 536-546.] claimed that there had been no method in the literature to find the fuzzy optimal solution of a FFLP problem without converting it into crisp linear programming problem, and proposed a technique for the same. Others showed that the fuzzy arithmetic operation used by Khan et al. (2013 had some problems in subtraction and division operations, which could lead to misleading results. Recently, Ezzati et al. (2014 [Ezzati, R., Khorram, E., & Enayati, R. (2014. A particular simplex algorithm to solve fuzzy lexicographic multi-objective linear programming problems and their sensitivity analysis on the priority of the fuzzy objective functions. Journal of Intelligent and Fuzzy Systems, 26(5, 2333-2358.] defined a new operation on symmetric trapezoidal fuzzy numbers and proposed a new algorithm to find directly a lexicographic/preemptive fuzzy optimal solution of a fuzzy lexicographic multi-objective linear programming problem by using new fuzzy arithmetic operations, but their model was not fully fuzzy optimization. In this paper, a new method, by using Ezzati et al. (2014’s fuzzy arithmetic operation and a fuzzy version of simplex algorithm, is proposed for solving FFLP problem whose parameters are represented by symmetric trapezoidal fuzzy number without converting the given problem into crisp equivalent problem. By using the proposed method, the fuzzy optimal solution of FFLP problem can be easily obtained. A numerical example is provided to illustrate the proposed method.
Axially symmetric Lorentzian wormholes in general relativity
International Nuclear Information System (INIS)
Schein, F.
1997-11-01
The field equations of Einstein's theory of general relativity, being local, do not fix the global structure of space-time. They admit topologically non-trivial solutions, including spatially closed universes and the amazing possibility of shortcuts for travel between distant regions in space and time - so-called Lorentzian wormholes. The aim of this thesis is to (mathematically) construct space-times which contain traversal wormholes connecting arbitrary distant regions of an asymptotically flat or asymptotically de Sitter universe. Since the wormhole mouths appear as two separate masses in the exterior space, space-time can at best be axially symmetric. We eliminate the non-staticity caused by the gravitational attraction of the mouths by anchoring them by strings held at infinity or, alternatively, by electric repulsion. The space-times are obtained by surgically grafting together well-known solutions of Einstein's equations along timelike hypersurfaces. This surgery naturally concentrates a non-zero stress-energy tensor on the boundary between the two space-times which can be investigated by using the standard thin shell formalism. It turns out that, when using charged black holes, the provided constructions are possible without violation of any of the energy conditions. In general, observers living in the axially symmetric, asymptotically flat (respectively asymptotically de Sitter) region axe able to send causal signals through the topologically non-trivial region. However, the wormhole space-times contain closed timelike curves. Because of this explicit violation of global hyperbolicity these models do not serve as counterexamples to known topological censorship theorems. (author)
Gravitational collapse and topology change in spherically symmetric dynamical systems
Energy Technology Data Exchange (ETDEWEB)
Csizmadia, Peter; Racz, Istvan, E-mail: cspeter@rmki.kfki.h, E-mail: iracz@rmki.kfki.h [RMKI H-1121 Budapest, Konkoly Thege Miklos ut 29-33 (Hungary)
2010-01-07
A new numerical framework, based on the use of a simple first-order strongly hyperbolic evolution equations, is introduced and tested in the case of four-dimensional spherically symmetric gravitating systems. The analytic setup is chosen such that our numerical method is capable of following the time evolution even after the appearance of trapped surfaces, more importantly, until the true physical singularities are reached. Using this framework, the gravitational collapse of various gravity-matter systems is investigated, with particular attention to the evolution in trapped regions. It is verified that, in advance of the formation of these curvature singularities, trapped regions develop in all cases, thereby supporting the validity of the weak cosmic censor hypothesis of Penrose. Various upper bounds on the rate of blow-up of the Ricci and Kretschmann scalars and the Misner-Sharp mass are provided. In spite of the unboundedness of the Ricci scalar, the Einstein-Hilbert action was found to remain finite in all the investigated cases. In addition, important conceptual issues related to the phenomenon of topology changes are discussed.
Mechanisms and Management of Diabetic Painful Distal Symmetrical Polyneuropathy
Tesfaye, Solomon; Boulton, Andrew J.M.; Dickenson, Anthony H.
2013-01-01
Although a number of the diabetic neuropathies may result in painful symptomatology, this review focuses on the most common: chronic sensorimotor distal symmetrical polyneuropathy (DSPN). It is estimated that 15–20% of diabetic patients may have painful DSPN, but not all of these will require therapy. In practice, the diagnosis of DSPN is a clinical one, whereas for longitudinal studies and clinical trials, quantitative sensory testing and electrophysiological assessment are usually necessary. A number of simple numeric rating scales are available to assess the frequency and severity of neuropathic pain. Although the exact pathophysiological processes that result in diabetic neuropathic pain remain enigmatic, both peripheral and central mechanisms have been implicated, and extend from altered channel function in peripheral nerve through enhanced spinal processing and changes in many higher centers. A number of pharmacological agents have proven efficacy in painful DSPN, but all are prone to side effects, and none impact the underlying pathophysiological abnormalities because they are only symptomatic therapy. The two first-line therapies approved by regulatory authorities for painful neuropathy are duloxetine and pregabalin. α-Lipoic acid, an antioxidant and pathogenic therapy, has evidence of efficacy but is not licensed in the U.S. and several European countries. All patients with DSPN are at increased risk of foot ulceration and require foot care, education, and if possible, regular podiatry assessment. PMID:23970715
Symmetric co-movement between Malaysia and Japan stock markets
Razak, Ruzanna Ab; Ismail, Noriszura
2017-04-01
The copula approach is a flexible tool known to capture linear, nonlinear, symmetric and asymmetric dependence between two or more random variables. It is often used as a co-movement measure between stock market returns. The information obtained from copulas such as the level of association of financial market during normal and bullish and bearish markets phases are useful for investment strategies and risk management. However, the study of co-movement between Malaysia and Japan markets are limited, especially using copulas. Hence, we aim to investigate the dependence structure between Malaysia and Japan capital markets for the period spanning from 2000 to 2012. In this study, we showed that the bivariate normal distribution is not suitable as the bivariate distribution or to present the dependence between Malaysia and Japan markets. Instead, Gaussian or normal copula was found a good fit to represent the dependence. From our findings, it can be concluded that simple distribution fitting such as bivariate normal distribution does not suit financial time series data, whose characteristics are often leptokurtic. The nature of the data is treated by ARMA-GARCH with heavy tail distributions and these can be associated with copula functions. Regarding the dependence structure between Malaysia and Japan markets, the findings suggest that both markets co-move concurrently during normal periods.
Two updating methods for dissipative models with non symmetric matrices
International Nuclear Information System (INIS)
Billet, L.; Moine, P.; Aubry, D.
1997-01-01
In this paper the feasibility of the extension of two updating methods to rotating machinery models is considered, the particularity of rotating machinery models is to use non-symmetric stiffness and damping matrices. It is shown that the two methods described here, the inverse Eigen-sensitivity method and the error in constitutive relation method can be adapted to such models given some modification.As far as inverse sensitivity method is concerned, an error function based on the difference between right hand calculated and measured Eigen mode shapes and calculated and measured Eigen values is used. Concerning the error in constitutive relation method, the equation which defines the error has to be modified due to the non definite positiveness of the stiffness matrix. The advantage of this modification is that, in some cases, it is possible to focus the updating process on some specific model parameters. Both methods were validated on a simple test model consisting in a two-bearing and disc rotor system. (author)
Tartrazine exclusion for allergic asthma.
Ardern, K D; Ram, F S
2001-01-01
Tartrazine is the best known and one of the most commonly used food additives. Food colorants are also used in many medications as well as foods. There has been conflicting evidence as to whether tartrazine causes exacerbations of asthma with some studies finding a positive association especially in individuals with cross-sensitivity to aspirin. To assess the overall effect of tartrazine (exclusion or challenge) in the management of asthma. A search was carried out using the Cochrane Airways Group specialised register. Bibliographies of each RCT was searched for additional papers. Authors of identified RCTs were contacted for further information for their trials and details of other studies. RCTs of oral administration of tartrazine (as a challenge) versus placebo or dietary avoidance of tartrazine versus normal diet were considered. Studies which focused upon allergic asthma, were also included. Studies of tartrazine exclusion for other allergic conditions such as hay fever, allergic rhinitis and eczema were only considered if the results for subjects with asthma were separately identified. Trials could be in either adults or children with asthma or allergic asthma (e.g. sensitivity to aspirin or food items known to contain tartrazine). Study quality was assessed and data abstracted by two reviewers independently. Outcomes were analysed using RevMan 4.1.1. Ninety abstracts were found, of which 18 were potentially relevant. Six met the inclusion criteria, but only three presented results in a format that permitted analysis and none could be combined in a meta-analysis. In none of the studies did tartrazine challenge or avoidance in diet significantly alter asthma outcomes. Due to the paucity of available evidence, it is not possible to provide firm conclusions as to the effects of tartrazine on asthma control. However, the six RCTs that could be included in this review all arrived at the same conclusion. Routine tartrazine exclusion may not benefit most patients
Exclusive electroproduction of pion pairs
International Nuclear Information System (INIS)
Warkentin, N.; Schaefer, A.; Diehl, M.; Ivanov, D. Yu.
2007-01-01
We investigate electroproduction of pion pairs on the nucleon in the framework of QCD factorization for hard exclusive processes. We extend previous analyses by taking the hard-scattering coefficients at next-to-leading order in α s . The dynamics of the produced pion pair is described by two-pion distribution amplitudes, for which we perform a detailed theoretical and phenomenological analysis. In particular, we obtain constraints on these quantities by comparing our results with measurements of angular observables that are sensitive to the interference between two-pion production in the isoscalar and isovector channels. (orig.)
Exclusion Bounds for Extended Anyons
Larson, Simon; Lundholm, Douglas
2018-01-01
We introduce a rigorous approach to the many-body spectral theory of extended anyons, that is quantum particles confined to two dimensions that interact via attached magnetic fluxes of finite extent. Our main results are many-body magnetic Hardy inequalities and local exclusion principles for these particles, leading to estimates for the ground-state energy of the anyon gas over the full range of the parameters. This brings out further non-trivial aspects in the dependence on the anyonic statistics parameter, and also gives improvements in the ideal (non-extended) case.
Surfactant-aided size exclusion chromatography
Horneman, D.A.; Wolbers, M.; Zomerdijk, M.; Ottens, M.; Keurentjes, J.T.F.; Wielen, van der L.A.M.
2004-01-01
The flexibility and selectivity of size exclusion chromatog. (SEC) for protein purifn. can be modified by adding non-ionic micelle-forming surfactants to the mobile phase. The micelles exclude proteins from a liq. phase similar to the exclusion effect of the polymer fibers of the size exclusion
Magnetospectroscopy of symmetric and anti-symmetric states in double quantum wells
Marchewka, M.; Sheregii, E. M.; Tralle, I.; Ploch, D.; Tomaka, G.; Furdak, M.; Kolek, A.; Stadler, A.; Mleczko, K.; Zak, D.; Strupinski, W.; Jasik, A.; Jakiela, R.
2008-02-01
The experimental results obtained for magnetotransport in the InGaAs/InAlAs double quantum well (DQW) structures of two different shapes of wells are reported. A beating effect occurring in the Shubnikov-de Haas (SdH) oscillations was observed for both types of structures at low temperatures in the parallel transport when the magnetic field was perpendicular to the layers. An approach for the calculation of the Landau level energies for DQW structures was developed and then applied to the analysis and interpretation of the experimental data related to the beating effect. We also argue that in order to account for the observed magnetotransport phenomena (SdH and integer quantum Hall effect), one should introduce two different quasi-Fermi levels characterizing two electron subsystems regarding the symmetry properties of their states, symmetric and anti-symmetric ones, which are not mixed by electron-electron interaction.
International Nuclear Information System (INIS)
Bruckman, W.
1986-01-01
The inverse scattering method of Belinsky and Zakharov is used to investigate axially symmetric stationary vacuum soliton solutions in the five-dimensional representation of the Brans-Dicke-Jordan theory of gravitation, where the scalar field of the theory is an element of a five-dimensional metric. The resulting equations for the spacetime metric are similar to those of solitons in general relativity, while the scalar field generated is the product of a simple function of the coordinates and an already known scalar field solution. A family of solutions is considered that reduce, in the absence of rotation, to the five-dimensional form of a well-known Weyl-Levi Civita axially symmetric static vacuum solution. With a suitable choice of parameters, this static limit becomes equivalent to the spherically symmetric solution of the Brans-Dicke theory. An exact metric, in which the Kerr-scalar McIntosh solution is a special case, is given explicitly
Implementation of exclusive truck facilities
Energy Technology Data Exchange (ETDEWEB)
Fekpe, E. [Battelle Memorial Inst., Columbus, OH (United States). Transportation Market Sector
2007-07-01
This paper discussed the issue of highway congestion, safety, and efficiency in freight movement on highways, with particular reference to the challenge of supporting increasing capacity demand from truck traffic. Innovative and practical solutions are needed to address the growing need for more efficient freight movement while maintaining acceptable levels of safety on highways. The concept of exclusive truck facilities (ETFs) is becoming an attractive option as a feasible strategy to help stabilize traffic flow, reduce congestion, improve safety, enhance transportation system management, improve access to freight facilities, and improve efficiency in freight movement along corridors of national importance. ETFs can either be truck only lanes or truckways. Passenger cars may not use ETFs. However, the use of ETFs could involve high costs of construction, maintenance, and acquisition of additional right of way. A cost-benefit analysis was performed for alternative ETF configurations under different traffic and site characteristics. A set of criteria was then proposed for identifying suitable locations for exclusive truck lanes. It was proposed that ETFs are economically feasible at locations with traffic volume of 100,000 vehicles per day or more and with a truck volume of at least 25 per cent of the traffic. In addition, the rate of truck-involved fatal crashes and level of service should be used to prioritize preliminary candidate locations that satisfy the traffic criteria. Consideration should also be given to the existence of freight terminals, ports, processing centers or regional distribution centres that are close to highways. 11 refs., 1 tab.
Exclusive scattering off the deuteron
Energy Technology Data Exchange (ETDEWEB)
Amrath, D.
2007-12-15
Exclusive processes are a special class of processes giving insight into the inner structure of hadrons. In this thesis we consider two exclusive processes and compute their total cross sections as well as the beam charge and beam polarization asymmetries for different kinematical constraints. These calculations o er the opportunity to get access to the nonperturbative GPDs. Theoretically they can be described with the help of models. The rst process we investigate contains a GPD of the pion, which is basically unknown so far. We include different models and make predictions for observables that could in principle be measured at HERMES at DESY and CLAS at JLab. The second process we consider is electron-deuteron scattering in the kinematical range where the deuteron breaks up into a proton and a neutron. This can be used to investigate the neutron, which cannot be taken as a target due to its lifetime of approximately 15 minutes. For the calculation of the electron-deuteron cross section we implement models for the proton and neutron GPDs. Once there are experimental data available our calculations are ready for comparison. (orig.)
Is the world simple or complicated
Barrow, John D
1998-01-01
Stop some particle physicists in the street and they will soon be trying to persuade you that the world is altogether simple and symmetrical. But stop a biologist, an economist, or a social scientist and they will tell you quite the opposite: the world is a higgledy-piggledy collection of complexities that owes little to symmetry and displays precious little simplicity. So who is right : is the world really complicated or is it simple ? We shall look at the reasoning that leads to these different conclusions, show why we got different answers to our question, and look at some of the recent developments that have taken place in the study of systems from sand-piles to music on the border between order and chaos. We shall also look at some of the connections between our aesthetic sensibilities and the structure of scientific theories.
International Nuclear Information System (INIS)
Collins, T.
1985-08-01
A simple criterion governs the beam distortion and/or loss of protons on a fast resonance crossing. Results from numerical integrations are illustrated for simple sextupole, octupole, and 10-pole resonances
Energy Technology Data Exchange (ETDEWEB)
Collins, T.
1985-08-01
A simple criterion governs the beam distortion and/or loss of protons on a fast resonance crossing. Results from numerical integrations are illustrated for simple sextupole, octupole, and 10-pole resonances.
Exclusive Breastfeeding Determinants in Breastfeeding Mother
Directory of Open Access Journals (Sweden)
Ika Mustika
2017-04-01
Full Text Available Exclusive breastfeeding until 6 month is very important for baby. The proportion of mothers who exclusively breastfeed their babies up to 6 months remains low. Factors influencing the exclusive breastfeeding namely sociodemograph factors , factors pre / post delivery , and psychosocial factors. This aims of this study to identify determinant factors of exclusive breastfeeding on mother. This research method is a systematic review , by analyzing the various studies on exclusive breastfeeding. There are 17 studies. The results obtained occupational factors most studied with significant results ( median OR = 1.265 . Psychosocial factors that have significant relationship is support of her husband (average OR = 4.716 and family support ( average OR = 1.770 . Conclusions : factors influencing the exclusive breastfeeding is occupational factor. Socialization and support from people nearby, health workers, and all parties is needed for exclusive breastfeeding for six months can be achieved.
Entangling capabilities of symmetric two-qubit gates
Indian Academy of Sciences (India)
Com- putational investigation of entanglement of such ensembles is therefore impractical for ... the computational complexity. Pairs of spin-1 ... tensor operators which can also provide different symmetric logic gates for quantum pro- ... that five of the eight, two-qubit symmetric quantum gates expressed in terms of our newly.
SUSY formalism for the symmetric double well potential
Indian Academy of Sciences (India)
symmetric double well potential barrier we have obtained a class of exactly solvable potentials subject to moving boundary condition. The eigenstates are also obtained by the same technique. Keywords. SUSY; moving boundary condition; exactly solvable; symmetric double well; NH3 molecule. PACS Nos 02.30.Ik; 03.50.
A New Formulation for Symmetric Implicit Runge-Kutta-Nystrom ...
African Journals Online (AJOL)
In this paper we derive symmetric stable Implicit Runge-Kutta –Nystrom Method for the Integration of General Second Order ODEs by using the collocation approach.The block hybrid method obtained by the evaluation of the continuous interpolant at different nodes of the polynomial is symmetric and suitable for stiff intial ...
Crossing symmetric solution of the Chew-Low equation
International Nuclear Information System (INIS)
McLeod, R.J.; Ernst, D.J.
1982-01-01
An N/D dispersion theory is developed which solves crossing symmetric Low equations. The method is used to generate crossing symmetric solutions to the Chew-Low model. We show why the technique originally proposed by Chew and Low was incapable of producing solutions. (orig.)
Sparse symmetric preconditioners for dense linear systems in electromagnetism
Carpentieri, Bruno; Duff, Iain S.; Giraud, Luc; Monga Made, M. Magolu
2004-01-01
We consider symmetric preconditioning strategies for the iterative solution of dense complex symmetric non-Hermitian systems arising in computational electromagnetics. In particular, we report on the numerical behaviour of the classical incomplete Cholesky factorization as well as some of its recent
Stability of transparent spherically symmetric thin shells and wormholes
International Nuclear Information System (INIS)
Ishak, Mustapha; Lake, Kayll
2002-01-01
The stability of transparent spherically symmetric thin shells (and wormholes) to linearized spherically symmetric perturbations about static equilibrium is examined. This work generalizes and systematizes previous studies and explores the consequences of including the cosmological constant. The approach shows how the existence (or not) of a domain wall dominates the landscape of possible equilibrium configurations
Coupled dilaton and electromagnetic field in cylindrically symmetric ...
Indian Academy of Sciences (India)
The dilaton black hole solutions have attracted considerable attention for the ... theory and study the corresponding cylindrically symmetric spacetime, where .... where Йm and Йe are integration constants to be interpreted later as the ..... feature is apparent for the cylindrically symmetric spacetime in the presence of the dila-.
Radon transformation on reductive symmetric spaces: support theorems
Kuit, J.J.|info:eu-repo/dai/nl/313872589
2011-01-01
In this thesis we introduce a class of Radon transforms for reductive symmetric spaces, including the horospherical transforms, and study some of their properties. In particular we obtain a generalization of Helgason's support theorem for the horospherical transform on a Riemannian symmetric space.
New approach to solve symmetric fully fuzzy linear systems
Indian Academy of Sciences (India)
In this paper, we present a method to solve fully fuzzy linear systems with symmetric coefﬁcient matrix. The symmetric coefﬁcient matrix is decomposed into two systems of equations by using Cholesky method and then a solution can be obtained. Numerical examples are given to illustrate our method.
Synthesis & Characterization of New bis-Symmetrical Adipoyl ...
African Journals Online (AJOL)
Full Title: Synthesis and Characterization of New bis-Symmetrical Adipoyl, Terepthaloyl, Chiral Diimido-di-L-alanine Diesters and Chiral Phthaloyl-L-alanine Ester of Tripropoxy p-tert-Butyl Calix[4]arene and Study of Their Hosting Ability for Alanine and Na+. Bis-symmetrical tripropoxy p-tert-butyl calix[4]arene esters were ...
FACES WITH LARGE DIAMETER ON THE SYMMETRICAL TRAVELING SALESMAN POLYTOPE
SIERKSMA, G; TIJSSEN, GA
This paper deals with the symmetric traveling salesman polytope and contains three main theorems. The first one gives a new characterization of (non)adjacency. Based on this characterization a new upper bound for the diameter of the symmetric traveling salesman polytope (conjectured to be 2 by M.
Symmetric metamaterials based on flower-shaped structure
International Nuclear Information System (INIS)
Tuong, P.V.; Park, J.W.; Rhee, J.Y.; Kim, K.W.; Cheong, H.; Jang, W.H.; Lee, Y.P.
2013-01-01
We proposed new models of metamaterials (MMs) based on a flower-shaped structure (FSS), whose “meta-atoms” consist of two flower-shaped metallic parts separated by a dielectric layer. Like the non-symmetric MMs based on cut-wire-pairs or electric ring resonators, the symmetrical FSS demonstrates the negative permeability at GHz frequencies. Employing the results, we designed a symmetric negative-refractive-index MM [a symmetric combined structure (SCS)], which is composed of FSSs and cross continuous wires. The MM properties of the FSS and the SCS are presented numerically and experimentally. - Highlights: • A new designed of sub-wavelength metamaterial, flower-shaped structure was proposed. • Flower-shaped meta-atom illustrated effective negative permeability. • Based on the meta-atom, negative refractive index was conventionally gained. • Negative refractive index was demonstrated with symmetric properties for electromagnetic wave. • Dimensional parameters were studied under normal electromagnetic wave
Fenton, N.; Neil, M.; Lagnado, D.; Marsh, W.; Yet, B.; Constantinou, A.
2016-01-01
We show that existing Bayesian network (BN) modelling techniques cannot capture the correct intuitive reasoning in the important case when a set of mutually exclusive events need to be modelled as separate nodes instead of states of a single node. A previously proposed ‘solution’, which introduces a simple constraint node that enforces mutual exclusivity, fails to preserve the prior probabilities of the events, while other proposed solutions involve major changes to the original model. We pro...
efficient and convenient synthesis of symmetrical carboxylic
African Journals Online (AJOL)
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The product can be isolated by a simple extraction with organic solvent, and the catalyst ... reactant, either dissolved in water (liquid-liquid) or present in solid state ... solution was stirred for 16 h at 35 °C followed by filtration and washing with ...
Symmetric weak ternary quantum homomorphic encryption schemes
Wang, Yuqi; She, Kun; Luo, Qingbin; Yang, Fan; Zhao, Chao
2016-03-01
Based on a ternary quantum logic circuit, four symmetric weak ternary quantum homomorphic encryption (QHE) schemes were proposed. First, for a one-qutrit rotation gate, a QHE scheme was constructed. Second, in view of the synthesis of a general 3 × 3 unitary transformation, another one-qutrit QHE scheme was proposed. Third, according to the one-qutrit scheme, the two-qutrit QHE scheme about generalized controlled X (GCX(m,n)) gate was constructed and further generalized to the n-qutrit unitary matrix case. Finally, the security of these schemes was analyzed in two respects. It can be concluded that the attacker can correctly guess the encryption key with a maximum probability pk = 1/33n, thus it can better protect the privacy of users’ data. Moreover, these schemes can be well integrated into the future quantum remote server architecture, and thus the computational security of the users’ private quantum information can be well protected in a distributed computing environment.
Skyrmions and vector mesons: a symmetric approach
International Nuclear Information System (INIS)
Caldi, D.G.
1984-01-01
We propose an extension of the effective, low-energy chiral Lagrangian known as the Skyrme model, to one formulated by a non-linear sigma model generalized to include vector mesons in a symmetric way. The model is based on chiral SU(6) x SU(6) symmetry spontaneously broken to static SU(6). The rho and other vector mesons are dormant Goldstone bosons since they are in the same SU(6) multiplet as the pion and other pseudoscalars. Hence the manifold of our generalized non-linear sigma model is the coset space (SU(6) x SU(6))/Su(6). Relativistic effects, via a spin-dependent mass term, break the static SU(6) and give the vectors a mass. The model can then be fully relativistic and covariant. The lowest-lying Skyrmion in this model is the whole baryonic 56-plet, which splits into the octet and decuplet in the presence of relativistic SU(6)-breaking. Due to the built-in SU(6) and the presence of vector mesons, the model is expected to have better phenomenological results, as well as providing a conceptually more unified picture of mesons and baryons. 29 references
Randomized Symmetric Crypto Spatial Fusion Steganographic System
Directory of Open Access Journals (Sweden)
Viswanathan Perumal
2016-06-01
Full Text Available The image fusion steganographic system embeds encrypted messages in decomposed multimedia carriers using a pseudorandom generator but it fails to evaluate the contents of the cover image. This results in the secret data being embedded in smooth regions, which leads to visible distortion that affects the imperceptibility and confidentiality. To solve this issue, as well as to improve the quality and robustness of the system, the Randomized Symmetric Crypto Spatial Fusion Steganography System is proposed in this study. It comprises three-subsystem bitwise encryption, spatial fusion, and bitwise embedding. First, bitwise encryption encrypts the message using bitwise operation to improve the confidentiality. Then, spatial fusion decomposes and evaluates the region of embedding on the basis of sharp intensity and capacity. This restricts the visibility of distortion and provides a high embedding capacity. Finally, the bitwise embedding system embeds the encrypted message through differencing the pixels in the region by 1, checking even or odd options and not equal to zero constraints. This reduces the modification rate to avoid distortion. The proposed heuristic algorithm is implemented in the blue channel, to which the human visual system is less sensitive. It was tested using standard IST natural images with steganalysis algorithms and resulted in better quality, imperceptibility, embedding capacity and invulnerability to various attacks compared to other steganographic systems.
Triple symmetric key cryptosystem for data security
Fuzail, C. Md; Norman, Jasmine; Mangayarkarasi, R.
2017-11-01
As the technology is getting spreads in the macro seconds of speed and in which the trend changing era from human to robotics the security issue is also getting increased. By means of using machine attacks it is very easy to break the cryptosystems in very less amount of time. Cryptosystem is a process which provides the security in all sorts of processes, communications and transactions to be done securely with the help of electronical mechanisms. Data is one such thing with the expanded implication and possible scraps over the collection of data to secure predominance and achievement, Information Security is the process where the information is protected from invalid and unverified accessibilities and data from mishandling. So the idea of Information Security has risen. Symmetric key which is also known as private key.Whereas the private key is mostly used to attain the confidentiality of data. It is a dynamic topic which can be implemented over different applications like android, wireless censor networks, etc. In this paper, a new mathematical manipulation algorithm along with Tea cryptosystem has been implemented and it can be used for the purpose of cryptography. The algorithm which we proposed is straightforward and more powerful and it will authenticate in harder way and also it will be very difficult to break by someone without knowing in depth about its internal mechanisms.
Experimental pseudo-symmetric trap EPSILON
International Nuclear Information System (INIS)
Skovoroda, A.A.; Arsenin, V.V.; Dlougach, E.D.; Kulygin, V.M.; Kuyanov, A.Yu.; Timofeev, A.V.; Zhil'tsov, V.A.; Zvonkov, A.V.
2001-01-01
Within the framework of the conceptual project 'Adaptive Plasma EXperiment' a trap with the closed magnetic field lines 'Experimental Pseudo-Symmetric trap' is examined. The project APEX is directed at the theoretical and experimental development of physical foundations for stationary thermonuclear reactor on the basis of an alternative magnetic trap with tokamak-level confinement of high β plasma. The fundamental principle of magnetic field pseudosymmetry that should be satisfied for plasma to have tokamak-like confinement is discussed. The calculated in paraxial approximation examples of pseudosymmetric curvilinear elements with poloidal direction of B isolines are adduced. The EPSILON trap consisting of two straight axisymmetric mirrors linked by two curvilinear pseudosymmetric elements is considered. The plasma currents are short-circuited within the curvilinear element what increases the equilibrium β. The untraditional scheme of MHD stabilization of a trap with the closed field lines by the use of divertor inserted into axisymmetric mirror is analyzed. The experimental installation EPSILON-OME that is under construction for experimental check of divertor stabilization is discussed. The possibility of ECR plasma production in EPSILON-OME under conditions of high density and small magnetic field is examined. (author)
Left-right symmetric superstring supergravitation
International Nuclear Information System (INIS)
Burova, M.V.; Ter-Martirosyan, K.E.
1988-01-01
A left-right (L-R) symmetric model of four-dimensional supergravitation with a SO(10) gauge group obtained as the low-energy limit is superstring theory is considered. The spectrum of the gauge fields and their interactions are in agreement with the Weinberg-Salam theory. In addition, the model includes heavy W R ± and Z μ ' bosons. Beside the N g =3 generations of the 16-plets the SO(10) model includes the fragments of such generations which play the role of Higgs particles and also scalar chiral filds, the number of which exceeds by one the number of generations. As a result the neutrinos of each generation obtain a stable small Majorana mass. It is shown that the scalar field potential leads to spontaneous violation of the SU(2) R group and L-R symmetry and at low energies the standard Weinberg-Salam theory appears. However, reasonable values of X bosons masses M x and sun 2 Θ W (Θ W is the Weinberg angle) can be obtained in the model only in the case of high mass scale M R ∼10 10 -10 12 GeV of the right group SU(2) R violation
Symmetric charge transfer cross section of uranium
International Nuclear Information System (INIS)
Shibata, Takemasa; Ogura, Koichi
1995-03-01
Symmetric charge transfer cross section of uranium was calculated under consideration of reaction paths. In the charge transfer reaction a d 3/2 electron in the U atom transfers into the d-electron site of U + ( 4 I 9/2 ) ion. The J value of the U atom produced after the reaction is 6, 5, 4 or 3, at impact energy below several tens eV, only resonant charge transfer in which the product atom is ground state (J=6) takes place. Therefore, the cross section is very small (4-5 x 10 -15 cm 2 ) compared with that considered so far. In the energy range of 100-1000eV the cross section increases with the impact energy because near resonant charge transfer in which an s-electron in the U atom transfers into the d-electron site of U + ion. Charge transfer cross section between U + in the first excited state (289 cm -1 ) and U in the ground state was also obtained. (author)
Dynamics of an exclusion process with creation and annihilation
International Nuclear Information System (INIS)
Juhasz, Robert; Santen, Ludger
2004-01-01
We examine the dynamical properties of an exclusion process with creation and annihilation of particles in the framework of a phenomenological domain-wall theory, by scaling arguments and by numerical simulation. We find that the length and the time scales are finite in the maximum current phase for finite creation and annihilation rates as opposed to the algebraically decaying correlations of the totally asymmetric simple exclusion process (TASEP). Critical exponents of the transition to the TASEP are determined. The case where bulk creation and annihilation rates vanish faster than the inverse of the system size N is also analysed. We point out that shock localization is possible even for rates proportional to N -a , 1 < a < 2
Two-body relativistic scattering with an O(1,1)-symmetric square-well potential
International Nuclear Information System (INIS)
Arshansky, R.; Horwitz, L.P.
1984-01-01
Scattering theory in the framework of a relativistic manifestly covariant quantum mechanics is applied to the relativistic analog of the nonrelativistic one-dimensional square-well potential, a two-body O(1,1)-symmetric hyperbolic square well in one space and one time dimension. The unitary S matrix is explicitly obtained. For well sizes large compared to the de Broglie wavelength of the reduced motion system, simple formulas are obtained for the associated sequence of resonances. This sequence has equally spaced levels and constant widths for higher resonances, and linearly increasing widths for lower-lying levels
Z4-symmetric factorized S-matrix in two space-time dimensions
International Nuclear Information System (INIS)
Zamolodchikov, A.B.
1979-01-01
The factorized S-matrix with internal symmetry Z 4 is constructed in two space-time dimensions. The two-particle amplitudes are obtained by means of solving the factorization, unitarity and analyticity equations. The solution of factorization equations can be expressed in terms of elliptic functions. The S-matrix cotains the resonance poles naturally. The simple formal relation between the general factorized S-matrices and the Baxter-type lattice transfer matrices is found. In the sense of this relation the Z 4 -symmetric S-matrix corresponds to the Baxter transfer matrix itself. (orig.)
International Nuclear Information System (INIS)
Vicente Alvarez, J.J.; Balseiro, C.A.; Ceccatto, H.A.
1995-07-01
We consider the introduction of fluctuation corrections to saddle- point results in the symmetric treatment of a mixed pseudofermion-boson representation of correlated electrons. In our calculations we avoid the complications of working in the discrete imaginary-time formulation of the functional integral, a procedure recently advocated in the literature as mandatory for this problem. For a simple two-site model our approach leads to approximate results in remarkable agreement with the exact ones, and without the spurious nonanalyticities of other similar treatments. (author). 14 refs, 2 figs
Physical aspects of pseudo-Hermitian and PT-symmetric quantum mechanics
International Nuclear Information System (INIS)
Mostafazadeh, Ali; Batal, Ahmet
2004-01-01
For a non-Hermitian Hamiltonian H possessing a real spectrum, we introduce a canonical orthonormal basis in which a previously introduced unitary mapping of H to a Hermitian Hamiltonian h takes a simple form. We use this basis to construct the observables O α of the quantum mechanics based on H. In particular, we introduce pseudo-Hermitian position and momentum operators and a pseudo-Hermitian quantization scheme that relates the latter to the ordinary classical position and momentum observables. These allow us to address the problem of determining the conserved probability density and the underlying classical system for pseudo-Hermitian and in particular PT-symmetric quantum systems. As a concrete example we construct the Hermitian Hamiltonian h, the physical observables O α , the localized states and the conserved probability density for the non-Hermitian PT-symmetric square well. We achieve this by employing an appropriate perturbation scheme. For this system, we conduct a comprehensive study of both the kinematical and dynamical effects of the non-Hermiticity of the Hamiltonian on various physical quantities. In particular, we show that these effects are quantum mechanical in nature and diminish in the classical limit. Our results provide an objective assessment of the physical aspects of PT-symmetric quantum mechanics and clarify its relationship with both conventional quantum mechanics and classical mechanics
Iterative solution of the Grad-Shafranov equation in symmetric magnetic coordinates
International Nuclear Information System (INIS)
Brambilla, Marco
2003-01-01
The inverse Grad-Shafranov equation for axisymmetric magnetohydrodynamic equilibria is reformulated in symmetric magnetic coordinates (in which magnetic field lines look 'straight', and the geometric toroidal angle is one of the coordinates). The poloidally averaged part of the equilibrium condition and Ampere law takes the form of two first-order ordinary differential equations, with the two arbitrary flux functions, pressure and force-free part of the current density, as sources. The condition for the coordinates to be flux coordinates, and the poloidally varying part of the equilibrium equation are similarly transformed into a set of first-order ordinary differential equations, with coefficients depending on the metric, and explicitly solved for the radial derivatives of the coefficients of the Fourier representation of the Cartesian coordinates in the poloidal angle. The derivation exploits the existence of Boozer-White coordinates, but does not require to find these coordinates explicitly; on the other hand, it offers a simple recipe to perform the transformation to Boozer-White coordinates, if required. Use of symmetric flux coordinates is advantageous for the formulation of many problems of equilibrium, stability, and wave propagation in tokamak plasmas, since these coordinates have the simplest metric of their class. It is also shown that in symmetric flux coordinates the Lagrangian equations of the drift motion of charged particles are automatically solved for the time derivatives, with right-hand sides closely related to the coefficients of the inverse Grad-Shafranov equation
Comparison of eigensolvers for symmetric band matrices.
Moldaschl, Michael; Gansterer, Wilfried N
2014-09-15
We compare different algorithms for computing eigenvalues and eigenvectors of a symmetric band matrix across a wide range of synthetic test problems. Of particular interest is a comparison of state-of-the-art tridiagonalization-based methods as implemented in Lapack or Plasma on the one hand, and the block divide-and-conquer (BD&C) algorithm as well as the block twisted factorization (BTF) method on the other hand. The BD&C algorithm does not require tridiagonalization of the original band matrix at all, and the current version of the BTF method tridiagonalizes the original band matrix only for computing the eigenvalues. Avoiding the tridiagonalization process sidesteps the cost of backtransformation of the eigenvectors. Beyond that, we discovered another disadvantage of the backtransformation process for band matrices: In several scenarios, a lot of gradual underflow is observed in the (optional) accumulation of the transformation matrix and in the (obligatory) backtransformation step. According to the IEEE 754 standard for floating-point arithmetic, this implies many operations with subnormal (denormalized) numbers, which causes severe slowdowns compared to the other algorithms without backtransformation of the eigenvectors. We illustrate that in these cases the performance of existing methods from Lapack and Plasma reaches a competitive level only if subnormal numbers are disabled (and thus the IEEE standard is violated). Overall, our performance studies illustrate that if the problem size is large enough relative to the bandwidth, BD&C tends to achieve the highest performance of all methods if the spectrum to be computed is clustered. For test problems with well separated eigenvalues, the BTF method tends to become the fastest algorithm with growing problem size.
Survival and transmission of symmetrical chromosomal aberrations
International Nuclear Information System (INIS)
Savage, J.R.K.
1979-01-01
The interaction between the lesions to produce chromosomal structural changes may be either asymmetrical (A) or symmetrical (S). In A, one or more acentric fragments are always produced, and there may also be the mechanical separation problems resulting from bridges at anaphase, while S-changes never produce fragment, and pose no mechanical problem in cell division. If A and S events occur with equal frequency, it might be an indication that they are truly the alternative modes of lesion interaction. Unstimulated lymphocytes were irradiated with 2.68 Gy 250 kV X-ray, and metaphases were sampled at 50 h after the stimulation. Preparations were complete diploid cells, and any obvious second division cells were rejected. So far as dermal repair and fibroblast functions are concerned, aberration burden seems to have little consequence from the view-point of the long-term survival in vivo. Large numbers of aberrations (mainly S translocation and terminal deletion) were found in the samples taken up to 60 years after therapy. Skin biopsies were removed 1 day and 6 months after irradiation and cultured. In irradiated cells, reciprocal translocations dominated, followed by terminal deletions, then inversions, while no chromosome-type aberration was seen in the control cells. a) The relative occurrence of A : S changes, b) long-term survival in vivo, c) the possibility of in vivo repair, and d) some unusual features of translocation found in Syrian hamsters are reviewed. The relevance or importance of major S events is clearly dependent upon the cells, the tissues or the organisms in which they occur. (Yamashita, S.)
Exclusive Higgs production at the LHC
Energy Technology Data Exchange (ETDEWEB)
Dechambre, Alice [Universite de Liege, Institut d' Astrophysique et de Geophysique, Allee du 6 aout, 17 - Bat. B5c, B-4000 Liege 1 - Sart-Tilman (Belgium); Staszewski, Rafal [IRFU/SPP, CEA-Saclay, bat. 141, 91191 Gif-sur-Yvette Cedex (France); Henryk Niewodniczanski, Institute of Nuclear Physics - PAN, Polish Academy of Sciences, ul. Radzikowskiego 152, 31-342 Krakow (Poland); Royon, Christophe [IRFU/SPP, CEA-Saclay, bat. 141, 91191 Gif-sur-Yvette Cedex (France)
2010-07-01
After a brief description of the models of exclusive diffractive Higgs production, we first evaluate the theoretical uncertainties that affect the calculation of exclusive cross section (jets, Higgs...). In addition, in view of the recent measurement of exclusive di-jet at CDF and the new implementation of the corresponding cross section in FPMC (Forward Physics Monte-Carlo), we developed an analysis strategy that can be used to narrow down these uncertainties with the help of early LHC measurement. (authors)
Negotiations and Exclusivity Contracts for Advertising
Anthony Dukes; Esther Gal–Or
2003-01-01
Exclusive advertising on a given media outlet is usually profitable for an advertiser because consumers are less aware of competing products. However, for such arrangements to exist, media must benefit as well. We examine conditions under which such exclusive advertising contracts benefit both advertisers and media outlets (referred to as ) by illustrating that exclusive equilibria arise in a theoretical model of the media, advertisers, and consumers who participate in both the product and me...
Inclusive education and social exclusion
Directory of Open Access Journals (Sweden)
Maria Luisa Bissoto
2013-01-01
Full Text Available The aim of this paper is critically examining assumptions underlying the Inclusive Education concept, arguing that this can only be effectively considered when understood in a broader context of social inclusion and exclusion. Methodologically, this article relies on international documents and bibliographic references about Inclusive Education, that have been chosen by systematize and characterize different social and educational inclusive practices, encouraging the elaboration of a general overview on this topic. The results of this analysis conclude that it is essential for Inclusive Education that educational institutions review their goals and reasons of social existence. In the concluding remarks it is argued that education is better understood as the act of encouraging and welcoming the efforts of individuals in their attempts to engage in social networking, which sustains life. This includes the acceptance of other reality interpretations and understanding that educational action cannot be restricted by the walls of institutions. It requires the participation of the whole community. Action perspectives likely to promote social inclusion and inclusive education are suggested.
Perturbative QCD and exclusive processes
International Nuclear Information System (INIS)
Bennett, J.; Hawes, F.; Zhao, M.; Zyla, P.
1991-01-01
The authors discuss perturbation theory as applied to particle physics calculations. In particle physics one is generally interested in the scattering amplitude for a system going from some initial state to a final state. The intermediate state or states are unknown. To get the scattering amplitude it is necessary to sum the contributions from processes which pass through all possible intermediate states. Intermediate states involve the exchange of intermediate vector bosons between the particles, and with this interaction is associated a coupling constant α. Each additional boson exchange involves an additional contribution of α to the coupling. If α is less than 1, one can see that the relative contribution of higher order processes is less and less important as α falls. In QCD the gluons serve as the intermediate vector bosons exchanged by quarks and gluons, and the interaction constant is not really a constant, but depends upon the distance between the particles. At short distances the coupling is small, and one can assume perturbative expansions may converge rapidly. Exclusive scattering processes, as opposed to inclusive, are those in which all of the final state products are detected. The authors then discuss the application of perturbative QCD to the deuteron. The issues of chiral conservation and color transparancy are also discussed, in the scheme of large Q 2 interations, where perturbative QCD should be applicable
Exclusive processes in pp collisions in CMS
da Silveira, Gustavo G.; Collaboration, for the CMS
2013-01-01
We report the results on the searches of exclusive production of low- and high-mass pairs with the Compact Muon Solenoid (CMS) detector in proton-proton collisions at $\\sqrt{s}$ = 7 TeV. The analyses comprise the central exclusive $\\gamma\\gamma$ production, the exclusive two-photon production of dileptons, $e^{+}e^{-}$ and $\\mu^{+}\\mu^{-}$, and the exclusive two-photon production of $W$ pairs in the asymmetric $e^{\\pm}\\mu^{\\mp}$ decay channel. No diphotons candidates are observed in data and ...
Directory of Open Access Journals (Sweden)
J. Sembian Ruso
2016-05-01
Full Text Available In this paper, we describe a simple and convenient conversion of aryl aldehydes to symmetrical dibenzyl ethers through reductive etherification. Similarly, unsymmetrical dibenzyl ether was obtained from aryl aldehyde and TES-protected benzyl alcohol. Triethyl silane with catalytic amount of InCl3 was found to be an efficient condition for the reductive etherification. Moreover, it exhibits remarkable functional group compatibility with yield ranging from good to excellent.
Radon transformation on reductive symmetric spaces:Support theorems
DEFF Research Database (Denmark)
Kuit, Job Jacob
2013-01-01
We introduce a class of Radon transforms for reductive symmetric spaces, including the horospherical transforms, and derive support theorems for these transforms. A reductive symmetric space is a homogeneous space G/H for a reductive Lie group G of the Harish-Chandra class, where H is an open sub...... is based on the relation between the Radon transform and the Fourier transform on G/H, and a Paley–Wiener-shift type argument. Our results generalize the support theorem of Helgason for the Radon transform on a Riemannian symmetric space....
Nilpotent orbits in real symmetric pairs and stationary black holes
International Nuclear Information System (INIS)
Dietrich, Heiko; De Graaf, Willem A.; Ruggeri, Daniele; Trigiante, Mario
2017-01-01
In the study of stationary solutions in extended supergravities with symmetric scalar manifolds, the nilpotent orbits of a real symmetric pair play an important role. In this paper we discuss two approaches to determine the nilpotent orbits of a real symmetric pair. We apply our methods to an explicit example, and thereby classify the nilpotent orbits of (SL 2 (R)) 4 acting on the fourth tensor power of the natural 2-dimensional SL 2 (R)-module. This makes it possible to classify all stationary solutions of the so-called STU-supergravity model. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
Color symmetrical superconductivity in a schematic nuclear quark model
DEFF Research Database (Denmark)
Bohr, Henrik; Providencia, C.; da Providencia, J.
2010-01-01
In this letter, a novel BCS-type formalism is constructed in the framework of a schematic QCD inspired quark model, having in mind the description of color symmetrical superconducting states. In the usual approach to color superconductivity, the pairing correlations affect only the quasi-particle...... states of two colors, the single-particle states of the third color remaining unaffected by the pairing correlations. In the theory of color symmetrical superconductivity here proposed, the pairing correlations affect symmetrically the quasi-particle states of the three colors and vanishing net color...
Highly-dispersive electromagnetic induced transparency in planar symmetric metamaterials.
Lu, Xiqun; Shi, Jinhui; Liu, Ran; Guan, Chunying
2012-07-30
We propose, design and experimentally demonstrate highly-dispersive electromagnetically induced transparency (EIT) in planar symmetric metamaterials actively switched and controlled by angles of incidence. Full-wave simulation and measurement results show EIT phenomena, trapped-mode excitations and the associated local field enhancement of two symmetric metamaterials consisting of symmetrically split rings (SSR) and a fishscale (FS) metamaterial pattern, respectively, strongly depend on angles of incidence. The FS metamaterial shows much broader spectral splitting than the SSR metamaterial due to the surface current distribution variation.
Geometric characteristics of aberrations of plane-symmetric optical systems
International Nuclear Information System (INIS)
Lu Lijun; Deng Zhiyong
2009-01-01
The geometric characteristics of aberrations of plane-symmetric optical systems are studied in detail with a wave-aberration theory. It is dealt with as an extension of the Seidel aberrations to realize a consistent aberration theory from axially symmetric to plane-symmetric systems. The aberration distribution is analyzed with the spot diagram of a ray and an aberration curve. Moreover, the root-mean-square value and the centroid of aberration distribution are discussed. The numerical results are obtained with the focusing optics of a toroidal mirror at grazing incidence.
Path integral representation of the symmetric Rosen-Morse potential
International Nuclear Information System (INIS)
Duru, I.H.
1983-09-01
An integral formula for the Green's function of symmetric Rosen-Morse potential is obtained by solving path integrals. The correctly normalized wave functions and bound state energy spectrum are derived. (author)
The geometrical theory of diffraction for axially symmetric reflectors
DEFF Research Database (Denmark)
Rusch, W.; Sørensen, O.
1975-01-01
The geometrical theory of diffraction (GTD) (cf. [1], for example) may be applied advantageously to many axially symmetric reflector antenna geometries. The material in this communication presents analytical, computational, and experimental results for commonly encountered reflector geometries...
Symmetric Pin Diversion Detection using a Partial Defect Detector (PDET)
International Nuclear Information System (INIS)
Sitaraman, S.; Ham, Y.S.
2009-01-01
Since the signature from the Partial Defect Detector (PDET) is principally dependent on the geometric layout of the guide tube locations, the capability of the technique in detecting symmetric diversion of pins needs to be determined. The Monte Carlo simulation study consisted of cases where pins were removed in a symmetric manner and the resulting signatures were examined. In addition to the normalized gamma-to-neutron ratios, the neutron and gamma signatures normalized to their maximum values, were also examined. Examination of the shape of the three curves as well as of the peak-to-valley differences in excess of the maximum expected in intact assemblies, indicated pin diversion. A set of simulations with various symmetric patterns of diversion were examined. The results from these studies indicated that symmetric diversions as low as twelve percent could be detected by this methodology
Systems of Differential Equations with Skew-Symmetric, Orthogonal Matrices
Glaister, P.
2008-01-01
The solution of a system of linear, inhomogeneous differential equations is discussed. The particular class considered is where the coefficient matrix is skew-symmetric and orthogonal, and where the forcing terms are sinusoidal. More general matrices are also considered.
A Paley-Wiener theorem for reductive symmetric spaces
Ban, E.P. van den; Schlichtkrull, H.
2006-01-01
Let X = G/H be a reductive symmetric space and K a maximal compact subgroup of G. The image under the Fourier transform of the space of K-finite compactly supported smooth functions on X is characterized.
Report on the Dynamical Evolution of an Axially Symmetric Quasar ...
Indian Academy of Sciences (India)
retical arguments together with some numerical evidence. The evolution of the orbits is studied, as mass is transported from the disk to the nucleus. ... galaxies and non-axially symmetric quasar models (see Papadopoulos & Caranicolas.
first principles derivation of a stress function for axially symmetric
African Journals Online (AJOL)
HOD
governing partial differential equations of linear isotropic elasticity were reduced to the solution of the biharmonic ... The stress function was then applied to solve the axially symmetric ..... [1] Borg S.K.: Fundamentals of Engineering Elasticity,.
Symmetrization of mathematical model of charge transport in semiconductors
Directory of Open Access Journals (Sweden)
Alexander M. Blokhin
2002-11-01
Full Text Available A mathematical model of charge transport in semiconductors is considered. The model is a quasilinear system of differential equations. A problem of finding an additional entropy conservation law and system symmetrization are solved.
An algebraic approach to the non-symmetric Macdonald polynomial
International Nuclear Information System (INIS)
Nishino, Akinori; Ujino, Hideaki; Wadati, Miki
1999-01-01
In terms of the raising and lowering operators, we algebraically construct the non-symmetric Macdonald polynomials which are simultaneous eigenfunctions of the commuting Cherednik operators. We also calculate Cherednik's scalar product of them
Hardware Realization of Chaos Based Symmetric Image Encryption
Barakat, Mohamed L.
2012-01-01
This thesis presents a novel work on hardware realization of symmetric image encryption utilizing chaos based continuous systems as pseudo random number generators. Digital implementation of chaotic systems results in serious degradations
Experimental technique of calibration of symmetrical air pollution ...
Indian Academy of Sciences (India)
Based on the inherent property of symmetry of air pollution models, a Symmetrical Air Pollution. Model ... process is in compliance with air pollution regula- ..... Ground simulation is achieved through MATLAB package which is based on least-.
Hardware Realization of Chaos-based Symmetric Video Encryption
Ibrahim, Mohamad A.
2013-01-01
This thesis reports original work on hardware realization of symmetric video encryption using chaos-based continuous systems as pseudo-random number generators. The thesis also presents some of the serious degradations caused by digitally
Invariant subspaces in some function spaces on symmetric spaces. II
International Nuclear Information System (INIS)
Platonov, S S
1998-01-01
Let G be a semisimple connected Lie group with finite centre, K a maximal compact subgroup of G, and M=G/K a Riemannian symmetric space of non-compact type. We study the problem of describing the structure of closed linear subspaces in various function spaces on M that are invariant under the quasiregular representation of the group G. We consider the case when M is a symplectic symmetric space of rank 1
Symmetric coupling of four spin-1/2 systems
Suzuki, Jun; Englert, Berthold-Georg
2012-06-01
We address the non-binary coupling of identical angular momenta based upon the representation theory for the symmetric group. A correspondence is pointed out between the complete set of commuting operators and the reference-frame-free subsystems. We provide a detailed analysis of the coupling of three and four spin-1/2 systems and discuss a symmetric coupling of four spin-1/2 systems.
Multiple symmetrical lipomatosis (Madelung's disease) - a case report
International Nuclear Information System (INIS)
Vieira, Marcelo Vasconcelos; Abreu, Marcelo de; Furtado, Claudia Dietz; Silveira, Marcio Fleck da; Furtado, Alvaro Porto Alegre; Genro, Carlos Horacio; Grazziotin, Rossano Ughini
2001-01-01
Multiple symmetrical lipomatosis (Madelung's disease) is a rare disorder characterized by deep accumulation of fat tissue, involving mainly the neck, shoulders and chest. This disease is associated with heavy alcohol intake and it is more common in men of Mediterranean origin. This disease can cause severe aesthetic deformities and progressive respiratory dysfunction. We report a case of a patient with multiple symmetrical lipomatosis and describe the clinical and radiological features of this disorder. (author)
Symmetrized neutron transport equation and the fast Fourier transform method
International Nuclear Information System (INIS)
Sinh, N.Q.; Kisynski, J.; Mika, J.
1978-01-01
The differential equation obtained from the neutron transport equation by the application of the source iteration method in two-dimensional rectangular geometry is transformed into a symmetrized form with respect to one of the angular variables. The discretization of the symmetrized equation leads to finite difference equations based on the five-point scheme and solved by use of the fast Fourier transform method. Possible advantages of the approach are shown on test calculations
2010-01-01
... 10 Energy 4 2010-01-01 2010-01-01 false Exclusions. 1009.4 Section 1009.4 Energy DEPARTMENT OF ENERGY (GENERAL PROVISIONS) GENERAL POLICY FOR PRICING AND CHARGING FOR MATERIALS AND SERVICES SOLD BY DOE § 1009.4 Exclusions. This part shall not apply when the amount to be priced or charged is...
Fighting poverty and exclusion through social investment
DEFF Research Database (Denmark)
Kvist, Jon
The fight against poverty and social exclusion is at the heart of the Europe 2020 strategy for smart, sustainable and inclusive growth. With more than 120 million people in the EU at risk of poverty or social exclusion, EU leaders have pledged to bring at least 20 million people out of poverty an...
2010-04-01
... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Exclusions. 1308.3... General Matters § 1308.3 Exclusions. (a) This part does not apply to any TVA contract which does not contain a disputes clause. (b) Except as otherwise specifically provided, this part does not apply to any...
Subspace exclusion zones for damage localization
DEFF Research Database (Denmark)
Bernal, Dionisio; Ulriksen, Martin Dalgaard
2018-01-01
, this is exploited in the context of structural damage localization to cast the Subspace Exclusion Zone (SEZ) scheme, which locates damage by reconstructing the captured field quantity shifts from analytical subspaces indexed by postulated boundaries, the so-called exclusion zones (EZs), in a model of the structure...
Critical properties of some aliphatic symmetrical ethers
International Nuclear Information System (INIS)
Nikitin, Eugene D.; Popov, Alexander P.; Bogatishcheva, Nataliya S.
2014-01-01
Highlights: • Critical properties of simple aliphatic ethers were measured. • The ethers decompose at near-critical temperatures. • Pulse-heating method with short residence times was used. -- Abstract: The critical temperatures T c and the critical pressures p c of dihexyl, dioctyl, and didecyl ethers have been measured. According to the measurements, the coordinates of the critical points are T c = (665 ± 7) K, p c = (1.44 ± 0.04) MPa for dihexyl ether, T c = (723 ± 7) K, p c = (1.19 ± 0.04) MPa for dioctyl ether, and T c = (768 ± 8) K, p c = (1.03 ± 0.03) MPa for didecyl ether. All the ethers studied degrade chemically at near-critical temperatures. A pulse-heating method applicable to measuring the critical properties of thermally unstable compounds has been used. The times from the beginning of a heating pulse to the moment of reaching the critical temperature were from 0.06 to 0.46 ms. The short residence times provide little decomposition of the substances in the course of the experiments. The critical properties of the ethers investigated in this work have been discussed together with those of methyl to butyl ethers. The experimental critical constants of the ethers have been compared with those estimated by the group-contribution methods of Wilson and Jasperson and Marrero and Gani. The Wilson/Jasperson method provides a better estimation of the critical temperatures and pressures of simple aliphatic ethers in comparison with the Marrero/Gani method if reliable normal boiling temperatures are used in the method of Wilson and Jasperson
Simple models of equilibrium and nonequilibrium phenomena
International Nuclear Information System (INIS)
Lebowitz, J.L.
1987-01-01
This volume consists of two chapters of particular interest to researchers in the field of statistical mechanics. The first chapter is based on the premise that the best way to understand the qualitative properties that characterize many-body (i.e. macroscopic) systems is to study 'a number of the more significant model systems which, at least in principle are susceptible of complete analysis'. The second chapter deals exclusively with nonequilibrium phenomena. It reviews the theory of fluctuations in open systems to which they have made important contributions. Simple but interesting model examples are emphasised
Exact stationary state for an asymmetric exclusion process with fully parallel dynamics
Gier, J.C.|info:eu-repo/dai/nl/170218430; Nienhuis, B.
The exact stationary state of an asymmetric exclusion process with fully parallel dynamics is obtained using the matrix product ansatz. We give a simple derivation for the deterministic case by a physical interpretation of the dimension of the matrices. We prove the stationarity via a cancellation
International Nuclear Information System (INIS)
Fuchs, J.
1990-08-01
A complete classification of simple currents of WZW theory is obtained. The proof is based on an analysis of the quantum dimensions of the primary fields. Simple currents are precisely the primaries with unit quantum dimension; for WZW theories explicit formulae for the quantum dimensions can be derived so that an identification of the fields with unit quantum dimension is possible. (author). 19 refs.; 2 tabs
Cotangent bundles over all the Hermitian symmetric spaces
International Nuclear Information System (INIS)
Arai, Masato; Baba, Kurando
2016-01-01
We construct the N = 2 supersymmetric nonlinear sigma models on the cotangent bundles over all the compact and non-compact Hermitian symmetric spaces. In order to construct them we use the projective superspace formalism which is an N = 2 off-shell superfield formulation in four-dimensional space-time. This formalism allows us to obtain the explicit expression of N = 2 supersymmetric nonlinear sigma models on the cotangent bundles over any Hermitian symmetric spaces in terms of the N =1 superfields, once the Kähler potentials of the base manifolds are obtained. Starting with N = 1 supersymmetric Kähler nonlinear sigma models on the Hermitian symmetric spaces, we extend them into the N = 2 supersymmetric models by using the projective superspace formalism and derive the general formula for the cotangent bundles over all the compact and non-compact Hermitian symmetric spaces. We apply to the formula for the non-compact Hermitian symmetric space E 7 /E 6 × U(1) 1 . (paper)
Optomechanically induced absorption in parity-time-symmetric optomechanical systems
Zhang, X. Y.; Guo, Y. Q.; Pei, P.; Yi, X. X.
2017-06-01
We explore the optomechanically induced absorption (OMIA) in a parity-time- (PT -) symmetric optomechanical system (OMS). By numerically calculating the Lyapunov exponents, we find out the stability border of the PT -symmetric OMS. The results show that in the PT -symmetric phase the system can be either stable or unstable depending on the coupling constant and the decay rate. In the PT -symmetric broken phase the system can have a stable state only for small gain rates. By calculating the transmission rate of the probe field, we find that there is an inverted optomechanically induced transparency (OMIT) at δ =-ωM and an OMIA at δ =ωM for the PT -symmetric optomechanical system. At each side of δ =-ωM there is an absorption window due to the resonance absorption of the two generated supermodes. Comparing with the case of optomechanics coupled to a passive cavity, we find that the active cavity can enhance the resonance absorption. The absorption rate at δ =ωM increases as the coupling strength between the two cavities increases. Our work provides us with a promising platform for controlling light propagation and light manipulation in terms of PT symmetry, which might have potential applications in quantum information processing and quantum optical devices.
A cascaded three-phase symmetrical multistage voltage multiplier
International Nuclear Information System (INIS)
Iqbal, Shahid; Singh, G K; Besar, R; Muhammad, G
2006-01-01
A cascaded three-phase symmetrical multistage Cockcroft-Walton voltage multiplier (CW-VM) is proposed in this report. It consists of three single-phase symmetrical voltage multipliers, which are connected in series at their smoothing columns like string of batteries and are driven by three-phase ac power source. The smoothing column of each voltage multiplier is charged twice every cycle independently by respective oscillating columns and discharged in series through load. The charging discharging process completes six times a cycle and therefore the output voltage ripple's frequency is of sixth order of the drive signal frequency. Thus the proposed approach eliminates the first five harmonic components of load generated voltage ripples and sixth harmonic is the major ripple component. The proposed cascaded three-phase symmetrical voltage multiplier has less than half the voltage ripple, and three times larger output voltage and output power than the conventional single-phase symmetrical CW-VM. Experimental and simulation results of the laboratory prototype are given to show the feasibility of proposed cascaded three-phase symmetrical CW-VM
Eisenhardt, K M; Sull, D N
2001-01-01
The success of Yahoo!, eBay, Enron, and other companies that have become adept at morphing to meet the demands of changing markets can't be explained using traditional thinking about competitive strategy. These companies have succeeded by pursuing constantly evolving strategies in market spaces that were considered unattractive according to traditional measures. In this article--the third in an HBR series by Kathleen Eisenhardt and Donald Sull on strategy in the new economy--the authors ask, what are the sources of competitive advantage in high-velocity markets? The secret, they say, is strategy as simple rules. The companies know that the greatest opportunities for competitive advantage lie in market confusion, but they recognize the need for a few crucial strategic processes and a few simple rules. In traditional strategy, advantage comes from exploiting resources or stable market positions. In strategy as simple rules, advantage comes from successfully seizing fleeting opportunities. Key strategic processes, such as product innovation, partnering, or spinout creation, place the company where the flow of opportunities is greatest. Simple rules then provide the guidelines within which managers can pursue such opportunities. Simple rules, which grow out of experience, fall into five broad categories: how- to rules, boundary conditions, priority rules, timing rules, and exit rules. Companies with simple-rules strategies must follow the rules religiously and avoid the temptation to change them too frequently. A consistent strategy helps managers sort through opportunities and gain short-term advantage by exploiting the attractive ones. In stable markets, managers rely on complicated strategies built on detailed predictions of the future. But when business is complicated, strategy should be simple.
Robust Visual Tracking via Exclusive Context Modeling
Zhang, Tianzhu; Ghanem, Bernard; Liu, Si; Xu, Changsheng; Ahuja, Narendra
2015-01-01
appearances as linear combinations of dictionary templates that are updated dynamically. Learning the representation of each particle is formulated as an exclusive sparse representation problem, where the overall dictionary is composed of multiple {group
Exclusive hadronic processes and color transparency
Indian Academy of Sciences (India)
It is known that at asymptotically large momentum transfer certain exclusive hadronic ... indicates that the Brodsky–Lepage factorization scheme fails, independent of ..... A basic feature of *-initiated reactions is that most events are knocked out.
Exclusion, exemption, clearance European Union approach
International Nuclear Information System (INIS)
Janssens, A.
1997-01-01
The presentation overviews the following issues: Euratom Basic Safety Standards; administrative requirements; radiation protection of the population. Scope of the Standards: natural radiation sources; exclusion. Exemption; Clearance; Import of radioactive scrap metal
Exclusion of pneumothorax by radionuclide lung scan
International Nuclear Information System (INIS)
Weiss, P.E.
1986-01-01
A case is reported in which ventilation lung imaging was useful in excluding a large pneumothorax. This technique may be helpful in patients with emphysema in whom exclusion of pneumothorax by radiographic criteria might be difficult
Imaging partons in exclusive scattering processes
Energy Technology Data Exchange (ETDEWEB)
Diehl, Markus
2012-06-15
The spatial distribution of partons in the proton can be probed in suitable exclusive scattering processes. I report on recent performance estimates for parton imaging at a proposed Electron-Ion Collider.
Nonlinear Cross-Diffusion with Size Exclusion
Burger, Martin; Di Francesco, Marco; Pietschmann, Jan-Frederik; Schlake, Bä rbel
2010-01-01
The aim of this paper is to investigate the mathematical properties of a continuum model for diffusion of multiple species incorporating size exclusion effects. The system for two species leads to nonlinear cross-diffusion terms with double
Exclusion, Violence, and Community Responses in Central ...
International Development Research Centre (IDRC) Digital Library (Canada)
Personal
2015-05-13
May 13, 2015 ... similar conditions of social exclusion, different levels of violence can be explained because communities capacities to face violence. • Methodology: ... in El Salvador. • Mix of quantitative and qualitative techniques of research.
Exclusive processes at high momentum transfer
Radyushkin, Anatoly; Stoker, Paul
2002-01-01
This book focuses on the physics of exclusive processes at high momentum transfer and their description in terms of generalized parton distributions, perturbative QCD, and relativistic quark models. It covers recent developments in the field, both theoretical and experimental.
The "symmetrical turn" in the study of colective action
Directory of Open Access Journals (Sweden)
Israel Rodríguez Giralt
2008-11-01
Full Text Available Conceptualising and understanding forms of collective action is one of the historic preoccupations of social thought. Good evidence of this can be found in the long line of disputes and polemics that runs through the history of thought about these social phenomena. It shows the difficulty social sciences have faced, and continue to face, when it comes to defining, explaining and delineating a phenomena as ephemeral and liminal as this one.In this context, I propose that a discussion of the implications an STS focus could have for the analysis of contemporary collective action. The main hypothesis I develop states that the conceptual and methodological baggage that goes with the Actor-Network theory (ANT, and its shaping into what has been called the 'symmetrical turn' in the social sciences, become a fundamental resource for renewing and enriching the analysis of collective action. For this, I will bring together two main contributions: its alternative understanding of social action (to explain the social it is necessary to leave the exclusive concern with social relations aside and take into account the non-human actors, such as the technical procedures in which they are involved; and its original definition of the “collective” (the collective is basically an aggregate of humans and non-humans, without predefined borders, it is just the relational product created by the constant and precarious commitment between heterogeneous elements. Both contributions, I affirm, allow the opening of an interesting discussion about agency and the possibility of articulating a new theory of collective action that differs from the dominant traditions in that it considers and assumes the heterogeneous and relational character of all social actors, and, as such, it also assumes that all social action is the emergent effect, the interactive product of those hybrid collectives in action. To give an example of the fertility of this approach, I focus on an
Model of reversible vesicular transport with exclusion
International Nuclear Information System (INIS)
Bressloff, Paul C; Karamched, Bhargav R
2016-01-01
A major question in neurobiology concerns the mechanics behind the motor-driven transport and delivery of vesicles to synaptic targets along the axon of a neuron. Experimental evidence suggests that the distribution of vesicles along the axon is relatively uniform and that vesicular delivery to synapses is reversible. A recent modeling study has made explicit the crucial role that reversibility in vesicular delivery to synapses plays in achieving uniformity in vesicle distribution, so called synaptic democracy (Bressloff et al 2015 Phys. Rev. Lett. 114 168101). In this paper we generalize the previous model by accounting for exclusion effects (hard-core repulsion) that may occur between molecular motor-cargo complexes (particles) moving along the same microtubule track. The resulting model takes the form of an exclusion process with four internal states, which distinguish between motile and stationary particles, and whether or not a particle is carrying vesicles. By applying a mean field approximation and an adiabatic approximation we reduce the system of ODEs describing the evolution of occupation numbers of the sites on a 1D lattice to a system of hydrodynamic equations in the continuum limit. We find that reversibility in vesicular delivery allows for synaptic democracy even in the presence of exclusion effects, although exclusion does exacerbate nonuniform distributions of vesicles in an axon when compared with a model without exclusion. We also uncover the relationship between our model and other models of exclusion processes with internal states. (paper)
Association between Exclusive Breastfeeding and Child Development
Directory of Open Access Journals (Sweden)
Ghaniyyatul Khudri
2016-03-01
Full Text Available Background: Child development highly correlates with child’s quality. The fastest child development period is during the first three years, also called golden period. This research was aimed to discover correlation between exclussive breastfeeding and child development in Cipacing Village Jatinangor, district of Sumedang. Methods: This research was conducted using cross-sectional method in thirteen Pos Pelayanan Terpadu (Posyandu Cipacing Village in Jatinangor. One hundred and two children aged 12−24 months with their caregiver were recruited as respondents by using cluster sampling method. Hist ory of exclusive breastfeeding was assessed with questionnaire while child development status was assesed with Kuesioner Pra Skrining Perkembangan (KPSP in September 2013 after informed consent was obtained. Chi-square test analysis was performed to determine correlation between exclusive breastfeeding and child development status. Results: Overall, children in Cipacing Village had non-exclusive breastfeeding history (83.3%, and only 16.7% respondents had exclusive breastfeeding history. Meanwhile, 89.2% of children had normal development status, and 10.8% had delayed development status. Statistic analysis using chi-square test in the level of 95% confidence between exclusive breastfeeding and child development showed p=0.686 and odds ratio 2.133. Conclusions: There is no significant relationship between history of exclusive breastfeeding and child development status.
Decomposition of a symmetric second-order tensor
Heras, José A.
2018-05-01
In the three-dimensional space there are different definitions for the dot and cross products of a vector with a second-order tensor. In this paper we show how these products can uniquely be defined for the case of symmetric tensors. We then decompose a symmetric second-order tensor into its ‘dot’ part, which involves the dot product, and the ‘cross’ part, which involves the cross product. For some physical applications, this decomposition can be interpreted as one in which the dot part identifies with the ‘parallel’ part of the tensor and the cross part identifies with the ‘perpendicular’ part. This decomposition of a symmetric second-order tensor may be suitable for undergraduate courses of vector calculus, mechanics and electrodynamics.
Solitons in PT-symmetric potential with competing nonlinearity
International Nuclear Information System (INIS)
Khare, Avinash; Al-Marzoug, S.M.; Bahlouli, Hocine
2012-01-01
We investigate the effect of competing nonlinearities on beam dynamics in PT-symmetric potentials. In particular, we consider the stationary nonlinear Schrödinger equation (NLSE) in one dimension with competing cubic and generalized nonlinearity in the presence of a PT-symmetric potential. Closed form solutions for localized states are obtained. These solitons are shown to be stable over a wide range of potential parameters. The transverse power flow associated with these complex solitons is also examined. -- Highlights: ► Effect of competing nonlinearities on beam dynamics in PT-symmetric potentials. ► Closed form solutions for localized states are. ► The transverse power flow associated with these complex solitons is also examined.
Nilpotent orbits in real symmetric pairs and stationary black holes
Energy Technology Data Exchange (ETDEWEB)
Dietrich, Heiko [School of Mathematical Sciences, Monash University, VIC (Australia); De Graaf, Willem A. [Department of Mathematics, University of Trento, Povo (Italy); Ruggeri, Daniele [Universita di Torino, Dipartimento di Fisica (Italy); INFN, Sezione di Torino (Italy); Trigiante, Mario [DISAT, Politecnico di Torino (Italy)
2017-02-15
In the study of stationary solutions in extended supergravities with symmetric scalar manifolds, the nilpotent orbits of a real symmetric pair play an important role. In this paper we discuss two approaches to determine the nilpotent orbits of a real symmetric pair. We apply our methods to an explicit example, and thereby classify the nilpotent orbits of (SL{sub 2}(R)){sup 4} acting on the fourth tensor power of the natural 2-dimensional SL{sub 2}(R)-module. This makes it possible to classify all stationary solutions of the so-called STU-supergravity model. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
Tourist Demand Reactions: Symmetric or Asymmetric across the Business Cycle?
Bronner, Fred; de Hoog, Robert
2017-09-01
Economizing and spending priorities on different types of vacations are investigated during two periods: an economic downturn and returning prosperity. Two nation-wide samples of vacationers are used: one during a downturn, the other one at the start of the recovery period. Through comparing the results, conclusions can be drawn about symmetric or asymmetric tourist demand across the business cycle. The main summer holiday has an asymmetric profile: being fairly crisis-resistant during a recession and showing considerable growth during an expansion. This does not apply to short vacations and day trips, each having a symmetric profile: during a recession they experience substantial reductions and during expansion comparable growth. So when talking about tourist demand in general , one cannot say that it is symmetric or asymmetric across the business cycle: it depends on the type of vacation. Differences in tourist demand are best explained by the role of Quality-of-Life for vacationers.
Symmetric spaces and the Kashiwara-Vergne method
Rouvière, François
2014-01-01
Gathering and updating results scattered in journal articles over thirty years, this self-contained monograph gives a comprehensive introduction to the subject. Its goal is to: - motivate and explain the method for general Lie groups, reducing the proof of deep results in invariant analysis to the verification of two formal Lie bracket identities related to the Campbell-Hausdorff formula (the "Kashiwara-Vergne conjecture"); - give a detailed proof of the conjecture for quadratic and solvable Lie algebras, which is relatively elementary; - extend the method to symmetric spaces; here an obstruction appears, embodied in a single remarkable object called an "e-function"; - explain the role of this function in invariant analysis on symmetric spaces, its relation to invariant differential operators, mean value operators and spherical functions; - give an explicit e-function for rank one spaces (the hyperbolic spaces); - construct an e-function for general symmetric spaces, in the spirit of Kashiwara and Vergne's or...
Rings with involution whose symmetric elements are central
Directory of Open Access Journals (Sweden)
Taw Pin Lim
1980-01-01
Full Text Available In a ring R with involution whose symmetric elements S are central, the skew-symmetric elements K form a Lie algebra over the commutative ring S. The classification of such rings which are 2-torsion free is equivalent to the classification of Lie algebras K over S equipped with a bilinear form f that is symmetric, invariant and satisfies [[x,y],z]=f(y,zx−f(z,xy. If S is a field of char ≠2, f≠0 and dimK>1 then K is a semisimple Lie algebra if and only if f is nondegenerate. Moreover, the derived algebra K′ is either the pure quaternions over S or a direct sum of mutually orthogonal abelian Lie ideals of dim≤2.
Kinetic-energy distribution for symmetric fission of 236U
International Nuclear Information System (INIS)
Brissot, R.; Bocquet, J.P.; Ristori, C.; Crancon, J.; Guet, C.R.; Nifenecker, H.A.; Montoya, M.
1980-01-01
Fission fragment kinetic-energy distributions have been measured at the Grenoble high-flux reactor with the Lohengrin facility. Spurious events were eliminated in the symmetric region by a coherence test based on a time-of-flight measurement of fragment velocities. A Monte-Carlo calculation is then performed to correct the experimental data for neutron evaporation. The difference between the most probable kinetic energy in symmetric fission and the fission in which the heavy fragment is 'magic' (Zsub(H)=50) is found to be approximately =30 MeV. The results suggest that for the symmetric case the total excitation energy available at scission is shared equally among the fragments. (author)
The discrete dynamics of symmetric competition in the plane.
Jiang, H; Rogers, T D
1987-01-01
We consider the generalized Lotka-Volterra two-species system xn + 1 = xn exp(r1(1 - xn) - s1yn) yn + 1 = yn exp(r2(1 - yn) - s2xn) originally proposed by R. M. May as a model for competitive interaction. In the symmetric case that r1 = r2 and s1 = s2, a region of ultimate confinement is found and the dynamics therein are described in some detail. The bifurcations of periodic points of low period are studied, and a cascade of period-doubling bifurcations is indicated. Within the confinement region, a parameter region is determined for the stable Hopf bifurcation of a pair of symmetrically placed period-two points, which imposes a second component of oscillation near the stable cycles. It is suggested that the symmetric competitive model contains much of the dynamical complexity to be expected in any discrete two-dimensional competitive model.
Bound states for non-symmetric evolution Schroedinger potentials
Energy Technology Data Exchange (ETDEWEB)
Corona, Gulmaro Corona [Area de Analisis Matematico y sus Aplicaciones, Universidad Autonoma Metropolitana-Azcapotalco, Atzcapotzalco, DF (Mexico)). E-mail: ccg@correo.azc.uam.mx
2001-09-14
We consider the spectral problem associated with the evolution Schroedinger equation, (D{sup 2}+ k{sup 2}){phi}=u{phi}, where u is a matrix-square-valued function, with entries in the Schwartz class defined on the real line. The solution {phi}, called the wavefunction, consists of a function of one real variable, matrix-square-valued with entries in the Schwartz class. This problem has been dealt for symmetric potentials u. We found for the present case that the bound states are localized similarly to the scalar and symmetric cases, but by the zeroes of an analytic matrix-valued function. If we add an extra condition to the potential u, we can determine these states by an analytic scalar function. We do this by generalizing the scalar and symmetric cases but without using the fact that the Wronskian of a pair of wavefunction is constant. (author)
Solution of generalized shifted linear systems with complex symmetric matrices
International Nuclear Information System (INIS)
Sogabe, Tomohiro; Hoshi, Takeo; Zhang, Shao-Liang; Fujiwara, Takeo
2012-01-01
We develop the shifted COCG method [R. Takayama, T. Hoshi, T. Sogabe, S.-L. Zhang, T. Fujiwara, Linear algebraic calculation of Green’s function for large-scale electronic structure theory, Phys. Rev. B 73 (165108) (2006) 1–9] and the shifted WQMR method [T. Sogabe, T. Hoshi, S.-L. Zhang, T. Fujiwara, On a weighted quasi-residual minimization strategy of the QMR method for solving complex symmetric shifted linear systems, Electron. Trans. Numer. Anal. 31 (2008) 126–140] for solving generalized shifted linear systems with complex symmetric matrices that arise from the electronic structure theory. The complex symmetric Lanczos process with a suitable bilinear form plays an important role in the development of the methods. The numerical examples indicate that the methods are highly attractive when the inner linear systems can efficiently be solved.
Alabdulmohsin, Ibrahim M.
2018-03-07
We will begin our treatment of summability calculus by analyzing what will be referred to, throughout this book, as simple finite sums. Even though the results of this chapter are particular cases of the more general results presented in later chapters, they are important to start with for a few reasons. First, this chapter serves as an excellent introduction to what summability calculus can markedly accomplish. Second, simple finite sums are encountered more often and, hence, they deserve special treatment. Third, the results presented in this chapter for simple finite sums will, themselves, be used as building blocks for deriving the most general results in subsequent chapters. Among others, we establish that fractional finite sums are well-defined mathematical objects and show how various identities related to the Euler constant as well as the Riemann zeta function can actually be derived in an elementary manner using fractional finite sums.
Alabdulmohsin, Ibrahim M.
2018-01-01
We will begin our treatment of summability calculus by analyzing what will be referred to, throughout this book, as simple finite sums. Even though the results of this chapter are particular cases of the more general results presented in later chapters, they are important to start with for a few reasons. First, this chapter serves as an excellent introduction to what summability calculus can markedly accomplish. Second, simple finite sums are encountered more often and, hence, they deserve special treatment. Third, the results presented in this chapter for simple finite sums will, themselves, be used as building blocks for deriving the most general results in subsequent chapters. Among others, we establish that fractional finite sums are well-defined mathematical objects and show how various identities related to the Euler constant as well as the Riemann zeta function can actually be derived in an elementary manner using fractional finite sums.
Symmetric vs. asymmetric stem cell divisions: an adaptation against cancer?
Directory of Open Access Journals (Sweden)
Leili Shahriyari
Full Text Available Traditionally, it has been held that a central characteristic of stem cells is their ability to divide asymmetrically. Recent advances in inducible genetic labeling provided ample evidence that symmetric stem cell divisions play an important role in adult mammalian homeostasis. It is well understood that the two types of cell divisions differ in terms of the stem cells' flexibility to expand when needed. On the contrary, the implications of symmetric and asymmetric divisions for mutation accumulation are still poorly understood. In this paper we study a stochastic model of a renewing tissue, and address the optimization problem of tissue architecture in the context of mutant production. Specifically, we study the process of tumor suppressor gene inactivation which usually takes place as a consequence of two "hits", and which is one of the most common patterns in carcinogenesis. We compare and contrast symmetric and asymmetric (and mixed stem cell divisions, and focus on the rate at which double-hit mutants are generated. It turns out that symmetrically-dividing cells generate such mutants at a rate which is significantly lower than that of asymmetrically-dividing cells. This result holds whether single-hit (intermediate mutants are disadvantageous, neutral, or advantageous. It is also independent on whether the carcinogenic double-hit mutants are produced only among the stem cells or also among more specialized cells. We argue that symmetric stem cell divisions in mammals could be an adaptation which helps delay the onset of cancers. We further investigate the question of the optimal fraction of stem cells in the tissue, and quantify the contribution of non-stem cells in mutant production. Our work provides a hypothesis to explain the observation that in mammalian cells, symmetric patterns of stem cell division seem to be very common.
Niche-independent symmetrical self-renewal of a mammalian tissue stem cell.
Directory of Open Access Journals (Sweden)
Luciano Conti
2005-09-01
Full Text Available Pluripotent mouse embryonic stem (ES cells multiply in simple monoculture by symmetrical divisions. In vivo, however, stem cells are generally thought to depend on specialised cellular microenvironments and to undergo predominantly asymmetric divisions. Ex vivo expansion of pure populations of tissue stem cells has proven elusive. Neural progenitor cells are propagated in combination with differentiating progeny in floating clusters called neurospheres. The proportion of stem cells in neurospheres is low, however, and they cannot be directly observed or interrogated. Here we demonstrate that the complex neurosphere environment is dispensable for stem cell maintenance, and that the combination of fibroblast growth factor 2 (FGF-2 and epidermal growth factor (EGF is sufficient for derivation and continuous expansion by symmetrical division of pure cultures of neural stem (NS cells. NS cells were derived first from mouse ES cells. Neural lineage induction was followed by growth factor addition in basal culture media. In the presence of only EGF and FGF-2, resulting NS cells proliferate continuously, are diploid, and clonogenic. After prolonged expansion, they remain able to differentiate efficiently into neurons and astrocytes in vitro and upon transplantation into the adult brain. Colonies generated from single NS cells all produce neurons upon growth factor withdrawal. NS cells uniformly express morphological, cell biological, and molecular features of radial glia, developmental precursors of neurons and glia. Consistent with this profile, adherent NS cell lines can readily be established from foetal mouse brain. Similar NS cells can be generated from human ES cells and human foetal brain. The extrinsic factors EGF plus FGF-2 are sufficient to sustain pure symmetrical self-renewing divisions of NS cells. The resultant cultures constitute the first known example of tissue-specific stem cells that can be propagated without accompanying
Directory of Open Access Journals (Sweden)
Nan-Fu Chiu
2013-12-01
Full Text Available We report a novel design wherein high-refractive-index zinc oxide (ZnO intermediary layers are used in anti-symmetrically structured surface plasmon resonance (SPR devices to enhance signal quality and improve the full width at half maximum (FWHM of the SPR reflectivity curve. The surface plasmon (SP modes of the ZnO intermediary layer were excited by irradiating both sides of the Au film, thus inducing a high electric field at the Au/ZnO interface. We demonstrated that an improvement in the ZnO (002 crystal orientation led to a decrease in the FWHM of the SPR reflectivity curves. We optimized the design of ZnO thin films using different parameters and performed analytical comparisons of the ZnO with conventional chromium (Cr and indium tin oxide (ITO intermediary layers. The present study is based on application of the Fresnel equation, which provides an explanation and verification for the observed narrow SPR reflectivity curve and optical transmittance spectra exhibited by (ZnO/Au, (Cr/Au, and (ITO/Au devices. On exposure to ethanol, the anti-symmetrically structured showed a huge electric field at the Au/ZnO interface and a 2-fold decrease in the FWHM value and a 1.3-fold larger shift in angle interrogation and a 4.5-fold high-sensitivity shift in intensity interrogation. The anti-symmetrically structured of ZnO intermediate layers exhibited a wider linearity range and much higher sensitivity. It also exhibited a good linear relationship between the incident angle and ethanol concentration in the tested range. Thus, we demonstrated a novel and simple method for fabricating high-sensitivity, high-resolution SPR biosensors that provide high accuracy and precision over relevant ranges of analyte measurement.
Azzam, R M A
2015-12-01
Conditions for achieving equal and opposite angular deflections of a light beam by reflection and refraction at an air-dielectric boundary are determined. Such angularly symmetric beam splitting (ASBS) is possible only if the angle of incidence is >60° by exactly one third of the angle of refraction. This simple law, plus Snell's law, leads to several analytical results that clarify all aspects of this phenomenon. In particular, it is shown that the intensities of the two symmetrically deflected beams can be equalized by proper choice of the prism refractive index and the azimuth of incident linearly polarized light. ASBS enables a geometrically attractive layout of optical systems that employ multiple prism beam splitters.
Katz, Abbott
2011-01-01
Get the most out of Excel 2010 with Excel 2010 Made Simple - learn the key features, understand what's new, and utilize dozens of time-saving tips and tricks to get your job done. Over 500 screen visuals and clear-cut instructions guide you through the features of Excel 2010, from formulas and charts to navigating around a worksheet and understanding Visual Basic for Applications (VBA) and macros. Excel 2010 Made Simple takes a practical and highly effective approach to using Excel 2010, showing you the best way to complete your most common spreadsheet tasks. You'll learn how to input, format,
Mazo, Gary
2011-01-01
If you have a Droid series smartphone - Droid, Droid X, Droid 2, or Droid 2 Global - and are eager to get the most out of your device, Droids Made Simple is perfect for you. Authors Martin Trautschold, Gary Mazo and Marziah Karch guide you through all of the features, tips, and tricks using their proven combination of clear instructions and detailed visuals. With hundreds of annotated screenshots and step-by-step directions, Droids Made Simple will transform you into a Droid expert, improving your productivity, and most importantly, helping you take advantage of all of the cool features that c
International Nuclear Information System (INIS)
Sator, N.
2003-01-01
This article concerns the correspondence between thermodynamics and the morphology of simple fluids in terms of clusters. Definitions of clusters providing a geometric interpretation of the liquid-gas phase transition are reviewed with an eye to establishing their physical relevance. The author emphasizes their main features and basic hypotheses, and shows how these definitions lead to a recent approach based on self-bound clusters. Although theoretical, this tutorial review is also addressed to readers interested in experimental aspects of clustering in simple fluids
Thouzery, Michel
2014-01-01
Fondée par les producteurs du Syndicat Inter-Massifs pour la Production et l’Économie des Simples (S.I.M.P.L.E.S), l’association base son action sur la recherche et le maintien d’une production de qualité (herboristerie et préparations à base de plantes) qui prend en compte le respect de l’environnement et la pérennité des petits producteurs en zone de montagne. Actions de formation Stages de découverte de la flore médicinale sauvage, Stages de culture et transformation des plantes médicinale...
International Nuclear Information System (INIS)
Dobrzynski, L; Akjouj, A; Djafari-Rouhani, B; Al-Wahsh, H; Zielinski, P
2003-01-01
We present a simple multiplexing device made of two atomic chains coupled by two other transition metal atoms. We show that this simple atomic device can transfer electrons at a given energy from one wire to the other, leaving all other electron states unaffected. Closed-form relations between the transmission coefficients and the inter-atomic distances are given to optimize the desired directional electron ejection. Such devices can be adsorbed on insulating substrates and characterized by current surface technologies. (letter to the editor)
Some curvature properties of quarter symmetric metric connections
International Nuclear Information System (INIS)
Rastogi, S.C.
1986-08-01
A linear connection Γ ji h with torsion tensor T j h P i -T i h P j , where T j h is an arbitrary (1,1) tensor field and P i is a 1-form, has been called a quarter-symmetric connection by Golab. Some properties of such connections have been studied by Rastogi, Mishra and Pandey, and Yano and Imai. In this paper based on the curvature tensor of quarter-symmetric metric connection we define a tensor analogous to conformal curvature tensor and study some properties of such a tensor. (author)
Symmetric bends how to join two lengths of cord
Miles, Roger E
1995-01-01
A bend is a knot securely joining together two lengths of cord (or string or rope), thereby yielding a single longer length. There are many possible different bends, and a natural question that has probably occurred to many is: "Is there a 'best' bend and, if so, what is it?"Most of the well-known bends happen to be symmetric - that is, the two constituent cords within the bend have the same geometric shape and size, and interrelationship with the other. Such 'symmetric bends' have great beauty, especially when the two cords bear different colours. Moreover, they have the practical advantage o
Norm estimates of complex symmetric operators applied to quantum systems
International Nuclear Information System (INIS)
Prodan, Emil; Garcia, Stephan R; Putinar, Mihai
2006-01-01
This paper communicates recent results in the theory of complex symmetric operators and shows, through two non-trivial examples, their potential usefulness in the study of Schroedinger operators. In particular, we propose a formula for computing the norm of a compact complex symmetric operator. This observation is applied to two concrete problems related to quantum mechanical systems. First, we give sharp estimates on the exponential decay of the resolvent and the single-particle density matrix for Schroedinger operators with spectral gaps. Second, we provide new ways of evaluating the resolvent norm for Schroedinger operators appearing in the complex scaling theory of resonances
Exploring plane-symmetric solutions in f(R) gravity
Energy Technology Data Exchange (ETDEWEB)
Shamir, M. F., E-mail: farasat.shamir@nu.edu.pk [National University of Computer and Emerging Sciences, Department of Sciences and Humanities (Pakistan)
2016-02-15
The modified theories of gravity, especially the f(R) gravity, have attracted much attention in the last decade. This paper is devoted to exploring plane-symmetric solutions in the context of metric f(R) gravity. We extend the work on static plane-symmetric vacuum solutions in f(R) gravity already available in the literature [1, 2]. The modified field equations are solved using the assumptions of both constant and nonconstant scalar curvature. Some well-known solutions are recovered with power-law and logarithmic forms of f(R) models.
Characterization of Generalized Young Measures Generated by Symmetric Gradients
De Philippis, Guido; Rindler, Filip
2017-06-01
This work establishes a characterization theorem for (generalized) Young measures generated by symmetric derivatives of functions of bounded deformation (BD) in the spirit of the classical Kinderlehrer-Pedregal theorem. Our result places such Young measures in duality with symmetric-quasiconvex functions with linear growth. The "local" proof strategy combines blow-up arguments with the singular structure theorem in BD (the analogue of Alberti's rank-one theorem in BV), which was recently proved by the authors. As an application of our characterization theorem we show how an atomic part in a BD-Young measure can be split off in generating sequences.
Integrability and symmetric spaces. II- The coset spaces
International Nuclear Information System (INIS)
Ferreira, L.A.
1987-01-01
It shown that a sufficient condition for a model describing the motion of a particle on a coset space to possess a fundamental Poisson bracket relation, and consequently charges involution, is that it must be a symmetric space. The conditions a hamiltonian, or any function of the canonical variables, has to satisfy in order to commute with these charges are studied. It is shown that, for the case of non compact symmetric space, these conditions lead to an algebraic structure which plays an important role in the construction of conserved quantities. (author) [pt
Color-symmetric superconductivity in a phenomenological QCD model
DEFF Research Database (Denmark)
Bohr, Henrik; Providencia, C.; Providencia, J. da
2009-01-01
In this paper, we construct a theory of the NJL type where superconductivity is present, and yet the superconducting state remains, in the average, color symmetric. This shows that the present approach to color superconductivity is consistent with color singletness. Indeed, quarks are free...... in the deconfined phase, but the deconfined phase itself is believed to be a color singlet. The usual description of the color superconducting state violates color singletness. On the other hand, the color superconducting state here proposed is color symmetric in the sense that an arbitrary color rotation leads...
(Anti)symmetric multivariate exponential functions and corresponding Fourier transforms
International Nuclear Information System (INIS)
Klimyk, A U; Patera, J
2007-01-01
We define and study symmetrized and antisymmetrized multivariate exponential functions. They are defined as determinants and antideterminants of matrices whose entries are exponential functions of one variable. These functions are eigenfunctions of the Laplace operator on the corresponding fundamental domains satisfying certain boundary conditions. To symmetric and antisymmetric multivariate exponential functions there correspond Fourier transforms. There are three types of such Fourier transforms: expansions into the corresponding Fourier series, integral Fourier transforms and multivariate finite Fourier transforms. Eigenfunctions of the integral Fourier transforms are found
Positive projections of symmetric matrices and Jordan algebras
DEFF Research Database (Denmark)
Fuglede, Bent; Jensen, Søren Tolver
2013-01-01
An elementary proof is given that the projection from the space of all symmetric p×p matrices onto a linear subspace is positive if and only if the subspace is a Jordan algebra. This solves a problem in a statistical model.......An elementary proof is given that the projection from the space of all symmetric p×p matrices onto a linear subspace is positive if and only if the subspace is a Jordan algebra. This solves a problem in a statistical model....
Algorithms for sparse, symmetric, definite quadratic lambda-matrix eigenproblems
International Nuclear Information System (INIS)
Scott, D.S.; Ward, R.C.
1981-01-01
Methods are presented for computing eigenpairs of the quadratic lambda-matrix, M lambda 2 + C lambda + K, where M, C, and K are large and sparse, and have special symmetry-type properties. These properties are sufficient to insure that all the eigenvalues are real and that theory analogous to the standard symmetric eigenproblem exists. The methods employ some standard techniques such as partial tri-diagonalization via the Lanczos Method and subsequent eigenpair calculation, shift-and- invert strategy and subspace iteration. The methods also employ some new techniques such as Rayleigh-Ritz quadratic roots and the inertia of symmetric, definite, quadratic lambda-matrices
Determination of symmetrical index for 3H in river waters
International Nuclear Information System (INIS)
Jankovic, M.; Todorovic, D.; Jankovic, B.; Nikolic, J.; Sarap, N.
2011-01-01
The paper presents the results of determining the symmetric index, which describes the magnitude of the tritium content changes with time, for samples of Sava and Danube river waters and Mlaka creek water. The results cover the period from 2003 to 2008. It was shown that the value of the symmetric index is the highest for Mlaka samples, which is in accordance with the fact that in these samples the highest concentration of tritium was found in comparison with samples of the Sava and Danube. [sr
Flat synchronizations in spherically symmetric space-times
International Nuclear Information System (INIS)
Herrero, Alicia; Morales-Lladosa, Juan Antonio
2010-01-01
It is well known that the Schwarzschild space-time admits a spacelike slicing by flat instants and that the metric is regular at the horizon in the associated adapted coordinates (Painleve-Gullstrand metric form). We consider this type of flat slicings in an arbitrary spherically symmetric space-time. The condition ensuring its existence is analyzed, and then, we prove that, for any spherically symmetric flat slicing, the densities of the Weinberg momenta vanish. Finally, we deduce the Schwarzschild solution in the extended Painleve-Gullstrand-LemaItre metric form by considering the coordinate decomposition of the vacuum Einstein equations with respect to a flat spacelike slicing.
A simple application of the Newman-Penrose spin coefficient formalism
International Nuclear Information System (INIS)
Davis, T.M.
1976-01-01
A simple application of the Newman-Penrose formalism is given which can be used by those learning this theory. The spherically symmetric Einstein-Maxwell problem for the Reissner-Nordstrom solution is solved using the Newman-Penrose formalism. The calculation is carried out using a Minkowski null tetrad. (author)
Improved self-exclusion program: preliminary results.
Tremblay, Nicole; Boutin, Claude; Ladouceur, Robert
2008-12-01
The gambling industry has offered self-exclusion programs for quite a long time. Such measures are designed to limit access to gaming opportunities and provide problem gamblers with the help they need to cease or limit their gambling behaviour. However, few studies have empirically evaluated these programs. This study has three objectives: (1) to observe the participation in an improved self-exclusion program that includes an initial voluntary evaluation, phone support, and a mandatory meeting, (2) to evaluate satisfaction and usefulness of this service as perceived by self-excluders, (3) to measure the preliminary impact of this improved program. One hundred sixteen self-excluders completed a questionnaire about their satisfaction and their perception of the usefulness during the mandatory meeting. Among those participants, 39 attended an initial meeting. Comparisons between data collected at the initial meeting and data taken at the final meeting were made for those 39 participants. Data showed that gamblers chose the improved self-exclusion program 75% of the time; 25% preferred to sign a regular self-exclusion contract. Among those who chose the improved service, 40% wanted an initial voluntary evaluation and 37% of these individuals actually attended that meeting. Seventy percent of gamblers came to the mandatory meeting, which was a required condition to end their self-exclusion. The majority of participants were satisfied with the improved self-exclusion service and perceived it as useful. Major improvements were observed between the final and the initial evaluation on time and money spent, consequences of gambling, DSM-IV score, and psychological distress. The applicability of an improved self-exclusion program is discussed and, as shown in our study, the inclusion of a final mandatory meeting might not be so repulsive for self-excluders. Future research directives are also proposed.
DEFF Research Database (Denmark)
Rosendahl, Mads
2002-01-01
-like language. Our aim is to extract a simple notion of driving and show that even in this tamed form it has much of the power of more general notions of driving. Our driving technique may be used to simplify functional programs which use function composition and will often be able to remove intermediate data...
Dix, M. G.; Harrison, D. R.; Edwards, T. M.
1982-01-01
Bubble vial with external aluminum-foil electrodes is sensing element for simple indicating tiltmeter. To measure bubble displacement, bridge circuit detects difference in capacitance between two sensing electrodes and reference electrode. Tiltmeter was developed for experiment on forecasting seismic events by changes in Earth's magnetic field.
Eggen, Per-Odd
2009-01-01
This article describes the construction of an inexpensive, robust, and simple hydrogen electrode, as well as the use of this electrode to measure "standard" potentials. In the experiment described here the students can measure the reduction potentials of metal-metal ion pairs directly, without using a secondary reference electrode. Measurements…
International Nuclear Information System (INIS)
Blain, J.F.
1969-01-01
The results obtained by application to argon and sodium of the two important methods of studying the structure of liquids: scattering of X-rays and neutrons, are presented on one hand. On the other hand the principal models employed for reconstituting the structure of simple liquids are exposed: mathematical models, lattice models and their derived models, experimental models. (author) [fr
International Nuclear Information System (INIS)
De Luca, R; Faella, O
2014-01-01
Mathematical fireworks are reproduced in two dimensions by means of simple notions in kinematics and Newtonian mechanics. Extension of the analysis in three dimensions is proposed and the geometric figures the falling tiny particles make on the ground after explosion are determined. (paper)
African Journals Online (AJOL)
In the present study, 78 mapped simple sequence repeat (SSR) markers representing 11 linkage groups of adzuki bean were evaluated for transferability to mungbean and related Vigna spp. 41 markers amplified characteristic bands in at least one Vigna species. The transferability percentage across the genotypes ranged ...
Temiz, Burak Kagan; Yavuz, Ahmet
2015-01-01
This study was done to develop a simple and inexpensive wave driver that can be used in experiments on string waves. The wave driver was made using a battery-operated toy car, and the apparatus can be used to produce string waves at a fixed frequency. The working principle of the apparatus is as follows: shortly after the car is turned on, the…
International Nuclear Information System (INIS)
Xiao, D B; Li, Q S; Hou, Z Q; Wang, X H; Chen, Z H; Xia, D W; Wu, X Z
2016-01-01
This paper presents a novel differential capacitive silicon micro-accelerometer with symmetrical double-sided serpentine beam-mass sensing structure and glass–silicon–glass sandwich structure. The symmetrical double-sided serpentine beam-mass sensing structure is fabricated with a novel pre-buried mask fabrication technology, which is convenient for manufacturing multi-layer sensors. The glass–silicon–glass sandwich structure is realized by a double anodic bonding process. To solve the problem of the difficulty of leading out signals from the top and bottom layer simultaneously in the sandwich sensors, a silicon pillar structure is designed that is inherently simple and low-cost. The prototype is fabricated and tested. It has low noise performance (the peak to peak value is 40 μg) and μg-level Allan deviation of bias (2.2 μg in 1 h), experimentally demonstrating the effectiveness of the design and the novel fabrication technology. (paper)
Energy Technology Data Exchange (ETDEWEB)
Hod, Shahar [The Ruppin Academic Center, Emeq Hefer (Israel); The Hadassah Academic College, Jerusalem (Israel)
2017-12-15
It has recently been demonstrated that asymptotically flat neutral reflecting stars are characterized by an intriguing no-hair property. In particular, it has been proved that these horizonless compact objects cannot support spatially regular static matter configurations made of scalar (spin-0) fields, vector (spin-1) fields and tensor (spin-2) fields. In the present paper we shall explicitly prove that spherically symmetric compact reflecting stars can support stationary (rather than static) bound-state massive scalar fields in their exterior spacetime regions. To this end, we solve analytically the Klein-Gordon wave equation for a linearized scalar field of mass μ and proper frequency ω in the curved background of a spherically symmetric compact reflecting star of mass M and radius R{sub s}. It is proved that the regime of existence of these stationary composed star-field configurations is characterized by the simple inequalities 1 - 2M/R{sub s} < (ω/μ){sup 2} < 1. Interestingly, in the regime M/R{sub s} << 1 of weakly self-gravitating stars we derive a remarkably compact analytical equation for the discrete spectrum {ω(M,R_s, μ)}{sup n=∞}{sub n=1} of resonant oscillation frequencies which characterize the stationary composed compact-reflecting-star-linearized-massive-scalar-field configurations. Finally, we verify the accuracy of the analytically derived resonance formula of the composed star-field configurations with direct numerical computations. (orig.)
Nayak, Chaturbhuja; Oberai, Praveen; Varanasi, Roja; Baig, Hafeezullah; Ch, Raveender; Reddy, G R C; Devi, Pratima; S, Bhubaneshwari; Singh, Vikram; Singh, V P; Singh, Hari; Shitanshu, Shashi Shekhar
2013-04-01
To evaluate homeopathic treatment in the management of diabetic distal symmetric polyneuropathy. A prospective multi-centric clinical observational study was carried out from October 2005 to September 2009 by Central Council for Research in Homeopathy (CCRH) (India) at its five institutes/units. Patients suffering from diabetes mellitus (DM) and presenting with symptoms of diabetic polyneuropathy (DPN) were screened, investigated and were enrolled in the study after fulfilling the inclusion and exclusion criteria. Patients were evaluated by the diabetic distal symmetric polyneuropathy symptom score (DDSPSS) developed by the Council. A total of 15 homeopathic medicines were identified after repertorizing the nosological symptoms and signs of the disease. The appropriate constitutional medicine was selected and prescribed in 30, 200 and 1 M potency on an individualized basis. Patients were followed up regularly for 12 months. Out of 336 patients (167 males and 169 females) enrolled in the study, 247 patients (123 males and 124 females) were analyzed. All patients who attended at least three follow-up appointments and baseline curve conduction studies were included in the analysis.). A statistically significant improvement in DDSPSS total score (p = 0.0001) was found at 12 months from baseline. Most objective measures did not show significant improvement. Lycopodium clavatum (n = 132), Phosphorus (n = 27) and Sulphur (n = 26) were the medicines most frequently prescribed. Adverse event of hypoglycaemia was observed in one patient only. This study suggests homeopathic medicines may be effective in managing the symptoms of DPN patients. Further studies should be controlled and include the quality of life (QOL) assessment. Copyright © 2013 The Faculty of Homeopathy. Published by Elsevier Ltd. All rights reserved.
''Follow that quark!'' (and other exclusive stories)
International Nuclear Information System (INIS)
Carroll, A.S.
1987-01-01
Quarks are considered to be the basic constituents of matter. In a series of recent experiments, Carroll studied exclusive reactions as a means of determining the interactions between quarks. Quantum Chromo-dynamics (QCD) is the modern theory of the interaction of quarks. This theory explains how quarks are held together via the strong interaction in particles known as hadrons. Hadrons consisting of three quarks are called baryons. Hadrons made up of a quark and an antiquark are called mesons. In his lecture, Carroll describes what happens when two hadrons collide and scatter to large angles. The violence of the collision causes the gluons that bind the quarks in a particular hadron to temporarily lose their grip on particular quarks. Quarks scramble toward renewed unity with other quarks, and they undergo rearrangement, which generally results in additional new particles. A two-body exclusive reaction has occurred when the same number of particles exist before and after the collisions. At large angles these exclusive reactions are very rare. The labels on the quarks known as flavor enable the experimenter to follow the history of individual quarks in detail during these exclusive reactions. Carroll describes the equipment used in the experiment to measure short distance, hard collisions at large angles. The collisions he discusses occur when a known beam of mesons or protons collide with a stationary proton target. Finally, Carroll summarizes what the experiments have shown from the study of exclusive reactions and what light some of their results shed on the theory of QCD
Bilaterally symmetric Fourier approximations of the skull outlines of ...
Indian Academy of Sciences (India)
Present work illustrates a scheme of quantitative description of the shape of the skull outlines of temnospondyl amphibians using bilaterally symmetric closed Fourier curves. Some special points have been identified on the Fourier fits of the skull outlines, which are the local maxima, or minima of the distances from the ...
PEO nanocomposite polymer electrolyte for solid state symmetric
Indian Academy of Sciences (India)
Physical and electrochemical properties of polyethylene oxide (PEO)-based nanocomposite solid polymer electrolytes (NPEs) were investigated for symmetric capacitor applications. Nanosize fillers, i.e., Al2O3 and SiO2 incorporated polymer electrolyte exhibited higher ionic conductivity than those with filler-free composites ...
Symmetric approximations of the Navier-Stokes equations
International Nuclear Information System (INIS)
Kobel'kov, G M
2002-01-01
A new method for the symmetric approximation of the non-stationary Navier-Stokes equations by a Cauchy-Kovalevskaya-type system is proposed. Properties of the modified problem are studied. In particular, the convergence as ε→0 of the solutions of the modified problem to the solutions of the original problem on an infinite interval is established
Duality, phase structures, and dilemmas in symmetric quantum games
International Nuclear Information System (INIS)
Ichikawa, Tsubasa; Tsutsui, Izumi
2007-01-01
Symmetric quantum games for 2-player, 2-qubit strategies are analyzed in detail by using a scheme in which all pure states in the 2-qubit Hilbert space are utilized for strategies. We consider two different types of symmetric games exemplified by the familiar games, the Battle of the Sexes (BoS) and the Prisoners' Dilemma (PD). These two types of symmetric games are shown to be related by a duality map, which ensures that they share common phase structures with respect to the equilibria of the strategies. We find eight distinct phase structures possible for the symmetric games, which are determined by the classical payoff matrices from which the quantum games are defined. We also discuss the possibility of resolving the dilemmas in the classical BoS, PD, and the Stag Hunt (SH) game based on the phase structures obtained in the quantum games. It is observed that quantization cannot resolve the dilemma fully for the BoS, while it generically can for the PD and SH if appropriate correlations for the strategies of the players are provided
SUSY formalism for the symmetric double well potential
Indian Academy of Sciences (India)
Using first- and second-order supersymmetric Darboüx formalism and starting with symmetric double well potential barrier we have obtained a class of exactly solvable potentials subject to moving boundary condition. The eigenstates are also obtained by the same technique.
Initial value formulation for the spherically symmetric dust solution
International Nuclear Information System (INIS)
Liu, H.
1990-01-01
An initial value formulation for the dust solution with spherical symmetry is given explicitly in which the initial distributions of dust and its velocity on an initial surface are chosen to be the initial data. As special cases, the Friedmann universe, the Schwarzschild solution in comoving coordinates, and a spherically symmetric and radially inhomogeneous cosmological model are derived
Coupled dilaton and electromagnetic field in cylindrically symmetric ...
Indian Academy of Sciences (India)
An exact solution is obtained for coupled dilaton and electromagnetic ﬁeld in a cylindrically symmetric spacetime where an axial magnetic ﬁeld as well as a radial electric ﬁeld both are present. Depending on the choice of the arbitrary constants our solution reduces either to dilatonic gravity with pure electric ﬁeld or to that ...
PT-Symmetric Waveguides and the Lack of Variational Techniques
Czech Academy of Sciences Publication Activity Database
Krejčiřík, David
2012-01-01
Roč. 73, č. 1 (2012), s. 1-2 ISSN 0378-620X Institutional support: RVO:61389005 Keywords : Robin Laplacian * non-self-adjoint boundary conditions * complex symmetric operator * PT-symmetry * waveguides * discrete and essential spectra Subject RIV: BA - General Mathematics Impact factor: 0.713, year: 2012
Confining but chirally symmetric dense and cold matter
International Nuclear Information System (INIS)
Glozman, L. Ya.
2012-01-01
The possibility for existence of cold, dense chirally symmetric matter with confinement is reviewed. The answer to this question crucially depends on the mechanism of mass generation in QCD and interconnection of confinement and chiral symmetry breaking. This question can be clarified from spectroscopy of hadrons and their axial properties. Almost systematical parity doubling of highly excited hadrons suggests that their mass is not related to chiral symmetry breaking in the vacuum and is approximately chirally symmetric. Then there is a possibility for existence of confining but chirally symmetric matter. We clarify a possible mechanism underlying such a phase at low temperatures and large density. Namely, at large density the Pauli blocking prevents the gap equation to generate a solution with broken chiral symmetry. However, the chirally symmetric part of the quark Green function as well as all color non-singlet quantities are still infrared divergent, meaning that the system is with confinement. A possible phase transition to such a matter is most probably of the first order. This is because there are no chiral partners to the lowest lying hadrons.
Technical report: Electric field in not completely symmetric systems
International Nuclear Information System (INIS)
Vila, F.
1994-08-01
In this paper it is studied theoretically the electric field in the not completely symmetric system earthed metallic sphere-uniformly charged dielectric plan, for sphere surface points situated in the plan that contains sphere's center and vertical symmetry axe of dielectric plan. (author). 11 refs, 1 fig
Symmetrical waveguide devices fabricated by direct UV writing
DEFF Research Database (Denmark)
Færch, Kjartan Ullitz; Svalgaard, Mikael
2002-01-01
Power splitters and directional couplers fabricated by direct UV writing in index matched silica-on-silicon samples can suffer from an asymmetrical device performance, even though the UV writing is carried out in a symmetrical fashion. This effect originates from a reduced photosensitivity...
On the axially symmetric equilibrium of a magnetically confined plasma
International Nuclear Information System (INIS)
Lehnert, B.
1975-01-01
The axially symmetric equilibrium of a magnetically confined plasma is reconsidered, with the special purpose of studying high-beta schemes with a purely poloidal magnetic field. A number of special solutions of the pressure and magnetic flux functions are shown to exist, the obtained results may form starting-points in a further analysis of physically relevant configurations. (Auth.)
Symmetric structures of coherent states in superfluid helium-4
International Nuclear Information System (INIS)
Ahmad, M.
1981-02-01
Coherent States in superfluid helium-4 are discussed and symmetric structures are assigned to these states. Discrete and continuous series functions are exhibited for such states. Coherent State structure has been assigned to oscillating condensed bosons and their inter-relations and their effects on the superfluid system are analysed. (author)
Spectra of PT -symmetric Hamiltonians on tobogganic contours
Indian Academy of Sciences (India)
The term PT -symmetric quantum mechanics, although defined to be of a much broader use, was coined in tight connection with C. Bender's analysis of one- ... on the other hand, the other members of the family were strange Hamiltonians with imaginary potentials which do not appear physical at all. The aim of the.
Symmetrical and asymmetrical growth restriction in preterm-born children
Bocca-Tjeertes, Inger; Bos, Arend; Kerstjens, Jorien; de Winter, Andrea; Reijneveld, Sijmen
OBJECTIVE: To determine how symmetric (proportionate; SGR) and asymmetric (disproportionate; AGR) growth restriction influence growth and development in preterms from birth to 4 years. METHODS: This community-based cohort study of 810 children comprised 86 SGR, 61 AGR, and 663 non-growth restricted
Perception of the Symmetrical Patterning of Human Gait by Infants.
Booth, Amy E.; Pinto, Jeannine; Bertenthal, Bennett I.
2002-01-01
Two experiments tested infants' sensitivity to properties of point-light displays of a walker and a runner that were equivalent regarding the phasing of limb movements. Found that 3-, but not 5-month-olds, discriminated these displays. When the symmetrical phase-patterning of the runner display was perturbed by advancing two of its limbs by 25…
Rotationally symmetric numerical solutions to the sine-Gordon equation
DEFF Research Database (Denmark)
Olsen, O. H.; Samuelsen, Mogens Rugholm
1981-01-01
We examine numerically the properties of solutions to the spherically symmetric sine-Gordon equation given an initial profile which coincides with the one-dimensional breather solution and refer to such solutions as ring waves. Expanding ring waves either exhibit a return effect or expand towards...
Symmetrical Womanhood: The Educational Ideology of Activism at Wellesley.
Palmieri, Patricia Ann
1995-01-01
The ideology of higher education for women at Wellesley College in the late 19th and early 20th centuries is discussed in the context of feminism and the women's suffrage movement. "Symmetrical womanhood," a concept emphasizing balance of traditional roles and intellectual and community involvement, was a goal of Wellesley faculty of…
Normalizations of Eisenstein integrals for reductive symmetric spaces
van den Ban, E.P.; Kuit, Job
2017-01-01
We construct minimal Eisenstein integrals for a reductive symmetric space G/H as matrix coefficients of the minimal principal series of G. The Eisenstein integrals thus obtained include those from the \\sigma-minimal principal series. In addition, we obtain related Eisenstein integrals, but with
Analytic families of eigenfunctions on a reductive symmetric space
Ban, E.P. van den; Schlichtkrull, H.
2000-01-01
In harmonic analysis on a reductive symmetric space X an important role is played by families of generalized eigenfunctions for the algebra D (X) of invariant dierential operators. Such families arise for instance as matrix coeÆcients of representations that come in series, such as the (generalized)
Whittaker Vector of Deformed Virasoro Algebra and Macdonald Symmetric Functions
Yanagida, Shintarou
2016-03-01
We give a proof of Awata and Yamada's conjecture for the explicit formula of Whittaker vector of the deformed Virasoro algebra realized in the Fock space. The formula is expressed as a summation over Macdonald symmetric functions with factored coefficients. In the proof, we fully use currents appearing in the Fock representation of Ding-Iohara-Miki quantum algebra.
Plane Symmetric Cosmological Model with Quark and Strange ...
Indian Academy of Sciences (India)
Keywords. f(R,T) theory of gravity—plane symmetric space-time—quark and strange quark matter—constant deceleration parameter. 1. Introduction. Modern astrophysical observations point out that present expansion of the Universe is an accelerated epoch. The most fascinating evidence for this is found in measurements ...
Separator-Integrated, Reversely Connectable Symmetric Lithium-Ion Battery.
Wang, Yuhang; Zeng, Jiren; Cui, Xiaoqi; Zhang, Lijuan; Zheng, Gengfeng
2016-02-24
A separator-integrated, reversely connectable, symmetric lithium-ion battery is developed based on carbon-coated Li3V2(PO4)3 nanoparticles and polyvinylidene fluoride-treated separators. The Li3V2(PO4)3 nanoparticles are synthesized via a facile solution route followed by calcination in Ar/H2 atmosphere. Sucrose solution is used as the carbon source for uniform carbon coating on the Li3V2(PO4)3 nanoparticles. Both the carbon and the polyvinylidene fluoride treatments substantially improve the cycling life of the symmetric battery by preventing the dissolution and shuttle of the electroactive Li3V2(PO4)3. The obtained symmetric full cell exhibits a reversible capacity of ≈ 87 mA h g(-1), good cycling stability, and capacity retention of ≈ 70% after 70 cycles. In addition, this type of symmetric full cell can be operated in both forward and reverse connection modes, without any influence on the cycling of the battery. Furthermore, a new separator integration approach is demonstrated, which enables the direct deposition of electroactive materials for the battery assembly and does not affect the electrochemical performance. A 10-tandem-cell battery assembled without differentiating the electrode polarity exhibits a low thickness of ≈ 4.8 mm and a high output voltage of 20.8 V. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Is PT -symmetric quantum theory false as a fundamental theory?
Czech Academy of Sciences Publication Activity Database
Znojil, Miloslav
2016-01-01
Roč. 56, č. 3 (2016), s. 254-257 ISSN 1210-2709 R&D Projects: GA ČR GA16-22945S Institutional support: RVO:61389005 Keywords : quantum mechanics * PT-symmetric representations of observables * masurement outcomes Subject RIV: BE - Theoretical Physics
A New Symmetrical Unit for Breakwater Armour : First Tests
Salauddin, M.; Broere, A.; Van der Meer, J.W.; Verhagen, H.J.; Bijl, E.
2015-01-01
A new and symmetrical single layer armour unit, the crablock, has been designed in the UAE. One breakwater was reconstructed with crablock, but very limited testing had been performed. Just to become more acquainted with this new unit, pre-competitive research at a university has been performed,
Helically symmetric experiment, (HSX) goals, design and status
International Nuclear Information System (INIS)
Anderson, F.S.B.; Almagri, A.F.; Anderson, D.T.; Matthews, P.G.; Talmadge, J.N.; Shohet, J.L.
1995-01-01
HSX is a quasi-helically symmetric (QHS) stellarator currently under construction at the Torsatron-Stellarator Laboratory of the University of Wisconsin-Madison. This device is unique in its magnetic design in that the magnetic field spectrum possesses only a single dominant (helical) component. This design avoids the large direct orbit losses and the low-collisionality neoclassical losses associated with conventional stellarators. The restoration of symmetry to the confining magnetic field makes the neoclassical confinement in this device analogous to an axisymmetric q=1/3 tokamak. The HSX device has been designed with a clear set of primary physics goals: demonstrate the feasibility of construction of a QHS device, examine single particle confinement of injected ions with regard to magnetic field symmetry breaking, compare density and temperature profiles in this helically symmetric system to those for axisymmetric tokamaks and conventional stellarators, examine electric fields and plasma rotation with edge biasing in relation to L-H transitions in symmetric versus non-symmetric stellarator systems, investigate QHS effects on 1/v regime electron confinement, and examine how greatly-reduced neoclassical electron thermal conductivity compares to the experimental χ e profile. 3 refs., 4 figs., 1 tab
On the random geometry of a symmetric matter antimatter universe
International Nuclear Information System (INIS)
Aldrovandi, R.; Goto, M.
1977-05-01
A statistical analysis is made of the randon geometry of an early symmetric matter-antimatter universe model. Such a model is shown to determine the total number of the largest agglomerations in the universe, as well as of some special configurations. Constraints on the time development of the protoagglomerations are also obtained
A summary view of the symmetric cosmological model
International Nuclear Information System (INIS)
Aldrovandi, R.
1975-01-01
A brief analysis of cosmological models is done, beginning with the standard model and following with the symmetric model of Omnes. Some attempts have been made for the phase transition in thermal radiation at high temperatures, to the annihilation period and to coalescence. One model with equal amounts of matter and antimatter seems to be reasonable [pt
Compactons in PT-symmetric generalized Korteweg–de Vries ...
Indian Academy of Sciences (India)
... Lecture Workshops · Refresher Courses · Symposia · Live Streaming. Home; Journals; Pramana – Journal of Physics; Volume 73; Issue 2. Compactons in P T -symmetric generalized Korteweg–de Vries equations. Carl M Bender Fred Cooper Avinash Khare Bogdan Mihaila Avadh Saxena. Volume 73 Issue 2 August 2009 ...
New algorithms for the symmetric tridiagonal eigenvalue computation
Energy Technology Data Exchange (ETDEWEB)
Pan, V. [City Univ. of New York, Bronx, NY (United States)]|[International Computer Sciences Institute, Berkeley, CA (United States)
1994-12-31
The author presents new algorithms that accelerate the bisection method for the symmetric eigenvalue problem. The algorithms rely on some new techniques, which include acceleration of Newton`s iteration and can also be further applied to acceleration of some other iterative processes, in particular, of iterative algorithms for approximating polynomial zeros.
Strain-induced formation of fourfold symmetric SiGe quantum dot molecules.
Zinovyev, V A; Dvurechenskii, A V; Kuchinskaya, P A; Armbrister, V A
2013-12-27
The strain field distribution at the surface of a multilayer structure with disklike SiGe nanomounds formed by heteroepitaxy is exploited to arrange the symmetric quantum dot molecules typically consisting of four elongated quantum dots ordered along the [010] and [100] directions. The morphological transition from fourfold quantum dot molecules to continuous fortresslike quantum rings with an increasing amount of deposited Ge is revealed. We examine key mechanisms underlying the formation of lateral quantum dot molecules by using scanning tunneling microscopy and numerical calculations of the strain energy distribution on the top of disklike SiGe nanomounds. Experimental data are well described by a simple thermodynamic model based on the accurate evaluation of the strain dependent part of the surface chemical potential. The spatial arrangement of quantum dots inside molecules is attributed to the effect of elastic property anisotropy.
Mimoso, José Pedro; Mena, Filipe C
2010-01-01
We investigate spherically symmetric perfect fluid spacetimes and discuss the existence and stability of a dividing shell separating expanding and collapsing regions. We perform a 3+1 splitting and obtain gauge invariant conditions relating the intrinsic spatial curvature of the shells to the ADM mass and to a function of the pressure which we introduce and that generalises the Tolman-Oppenheimer-Volkoff equilibrium condition. We analyse the particular cases of the Lema\\^itre-Tolman-Bondi dust models with a cosmological constant as an example of a $\\Lambda$-CDM model and its generalization to contain a central perfect fluid core. These models provide simple, but physically interesting illustrations of our results.
Applying exclusion likelihoods from LHC searches to extended Higgs sectors
International Nuclear Information System (INIS)
Bechtle, Philip; Heinemeyer, Sven; Staal, Oscar; Stefaniak, Tim; Weiglein, Georg
2015-01-01
LHC searches for non-standard Higgs bosons decaying into tau lepton pairs constitute a sensitive experimental probe for physics beyond the Standard Model (BSM), such as supersymmetry (SUSY). Recently, the limits obtained from these searches have been presented by the CMS collaboration in a nearly model-independent fashion - as a narrow resonance model - based on the full 8 TeV dataset. In addition to publishing a 95 % C.L. exclusion limit, the full likelihood information for the narrowresonance model has been released. This provides valuable information that can be incorporated into global BSM fits. We present a simple algorithm that maps an arbitrary model with multiple neutral Higgs bosons onto the narrow resonance model and derives the corresponding value for the exclusion likelihood from the CMS search. This procedure has been implemented into the public computer code HiggsBounds (version 4.2.0 and higher). We validate our implementation by cross-checking against the official CMS exclusion contours in three Higgs benchmark scenarios in the Minimal Supersymmetric Standard Model (MSSM), and find very good agreement. Going beyond validation, we discuss the combined constraints of the ττ search and the rate measurements of the SM-like Higgs at 125 GeV in a recently proposed MSSM benchmark scenario, where the lightest Higgs boson obtains SM-like couplings independently of the decoupling of the heavier Higgs states. Technical details for how to access the likelihood information within HiggsBounds are given in the appendix. The program is available at http:// higgsbounds.hepforge.org. (orig.)
Lee, Myoung-Jae; Jung, Young-Dae
2018-05-01
The dispersion properties of surface dust ion-acoustic waves in a self-gravitating magnetized dusty plasma layer with the (r, q) distribution are investigated. The result shows that the wave frequency of the symmetric mode in the plasma layer decreases with an increase in the wave number. It is also shown that the wave frequency of the symmetric mode decreases with an increase in the spectral index r. However, the wave frequency of the anti-symmetric mode increases with an increase in the wave number. It is also found that the anti-symmetric mode wave frequency increases with an increase in the spectral index r. In addition, it is found that the influence of the self-gravitation on the symmetric mode wave frequency decreases with increasing scaled Jeans frequency. Moreover, it is found that the wave frequency of the symmetric mode increases with an increase in the dust charge; however, the anti-symmetric mode shows opposite behavior.
Testing the Pauli Exclusion Principle for Electrons
International Nuclear Information System (INIS)
Marton, J; Berucci, C; Cargnelli, M; Ishiwatari, T; Bartalucci, S; Bragadireanu, M; Curceanu, C; Guaraldo, C; Iliescu, M; Pietreanu, D; Piscicchia, K; Ponta, T; Vidal, A Romero; Scordo, A; Sirghi, D L; Bertolucci, S; Matteo, S Di; Egger, J-P; Laubenstein, M; Milotti, E
2013-01-01
One of the fundamental rules of nature and a pillar in the foundation of quantum theory and thus of modern physics is represented by the Pauli Exclusion Principle. We know that this principle is extremely well fulfilled due to many observations. Numerous experiments were performed to search for tiny violation of this rule in various systems. The experiment VIP at the Gran Sasso underground laboratory is searching for possible small violations of the Pauli Exclusion Principle for electrons leading to forbidden X-ray transitions in copper atoms. VIP is aiming at a test of the Pauli Exclusion Principle for electrons with high accuracy, down to the level of 10 −29 – 10 −30 , thus improving the previous limit by 3–4 orders of magnitude. The experimental method, results obtained so far and new developments within VIP2 (follow-up experiment at Gran Sasso, in preparation) to further increase the precision by 2 orders of magnitude will be presented
Digital exclusion in higher education contexts
DEFF Research Database (Denmark)
Khalid, Md. Saifuddin; Pedersen, Mette Jun Lykkegaard
2016-01-01
The integration and adoption of digital technologies have enabled improvements in the quality of and inclusion in higher education. However, a significant proportion of the population has either remained or become digitally excluded. This systematic literature review elucidates the factors...... underlying the concepts of “digital exclusion” and the “digital divide” in higher education. The identified factors are grouped into three categories: social exclusion (i.e., low income, ICT-avoidance as the norm, lack of motivation and commitment, and physical or mental disability), digital exclusion (i.......e., lack of hardware devices and Internet services) and accessibility (which include the division between rural and urban areas, as well as disparities in ICT literacy and information literacy). These factors are multi-tiered and overlapping. Studies on the digital divide, digital exclusion, and barriers...
Exclusive vector meson production at HERA
Energy Technology Data Exchange (ETDEWEB)
Szuba, Dorota [Hamburg University, Hamburg (Germany); Collaboration: H1 Collaboration; ZEUS Collaboration
2013-04-15
The exclusive photoproduction of {Upsilon} has been studied with the ZEUS detector in ep collisions at HERA. The exponential slope, b, of the |t|-dependence of the cross section, where t is the squared four-momentum transfer at the proton vertex, has been measured. This constitutes the first measurement of the |t|-dependence of the {gamma}p{yields}{Upsilon}p cross section. The differential crosssections as a function of t at lower energies of {gamma}p centre-of-mass has been studied in exclusive diffractive photoproduction of J/{psi} mesons with the H1 detector. The exclusive electroproduction of two pions has been measured by the ZEUS experiment. The two-pion invariant-mass distribution is interpreted in terms of the pion electromagnetic form factor, assuming that the studied mass range includes the contributions of the {rho}, {rho} Prime and . {rho}'' vector-meson states.
Exclusive vector meson production at HERA
International Nuclear Information System (INIS)
Szuba, Dorota
2013-01-01
The exclusive photoproduction of Υ has been studied with the ZEUS detector in ep collisions at HERA. The exponential slope, b, of the |t|-dependence of the cross section, where t is the squared four-momentum transfer at the proton vertex, has been measured. This constitutes the first measurement of the |t|-dependence of the γp→Υp cross section. The differential crosssections as a function of t at lower energies of γp centre-of-mass has been studied in exclusive diffractive photoproduction of J/ψ mesons with the H1 detector. The exclusive electroproduction of two pions has been measured by the ZEUS experiment. The two-pion invariant-mass distribution is interpreted in terms of the pion electromagnetic form factor, assuming that the studied mass range includes the contributions of the ρ, ρ′ and . ρ'' vector-meson states.
Cottrell, William; Montero, Miguel
2018-02-01
In this note we investigate the role of Lloyd's computational bound in holographic complexity. Our goal is to translate the assumptions behind Lloyd's proof into the bulk language. In particular, we discuss the distinction between orthogonalizing and `simple' gates and argue that these notions are useful for diagnosing holographic complexity. We show that large black holes constructed from series circuits necessarily employ simple gates, and thus do not satisfy Lloyd's assumptions. We also estimate the degree of parallel processing required in this case for elementary gates to orthogonalize. Finally, we show that for small black holes at fixed chemical potential, the orthogonalization condition is satisfied near the phase transition, supporting a possible argument for the Weak Gravity Conjecture first advocated in [1].
Unicameral (simple) bone cysts.
Baig, Rafath; Eady, John L
2006-09-01
Since their original description by Virchow, simple bone cysts have been studied repeatedly. Although these defects are not true neoplasms, simple bone cysts may create major structural defects of the humerus, femur, and os calcis. They are commonly discovered incidentally when x-rays are taken for other reasons or on presentation due to a pathologic fracture. Various treatment strategies have been employed, but the only reliable predictor of success of any treatment strategy is the age of the patient; those being older than 10 years of age heal their cysts at a higher rate than those under age 10. The goal of management is the formation of a bone that can withstand the stresses of use by the patient without evidence of continued bone destruction as determined by serial radiographic follow-up. The goal is not a normal-appearing x-ray, but a functionally stable bone.
Teenage pregnancy and exclusive breastfeeding rates.
Puapompong, Pawin; Raungrongmorakot, Kasem; Manolerdtewan, Wichian; Ketsuwan, Sukwadee; Wongin, Sinutchanan
2014-09-01
Teenage pregnancy is an important health issue globally and in Thailand Younger age mothers decide on the breastfeeding practices ofthe first 6-month. To find the rates of 6-month exclusive breastfeeding practices of teenage mothers and compare them with the rates of 6-month exclusive breastfeeding practices in mothers who are 20 years of age or more. Three thousand five hundred sixty three normal, postpartum women, who delivered without complications at the HRH Princess Maha Chakri Sirindhorn Medical Center in the Nakhon Nayok Province between 2010 and2013 were included in this study. At the second daypostpartum, the data of latch scores and the data of the practice of exclusive breastfeeding were collected Telephone follow-ups on the seventh, fourteenth, and forty-fifth postpartum days and at the second, fourth, and sixth month postpartum month were collected and used for exclusive breastfeeding data following discharge. Demographic data included the maternal age, parity, gestational age, marital status, occupation, religion, route ofdelivery, estimated blood loss, body mass index, nipple length, and the childs birth weight. The collected data was analyzed by the t-test, Chi-square, and odds ratio with 95% confidence interval. The percentage of teenage pregnancies was at 14.8% (527 cases). On postpartum day 2, the percentage of latch scores of 8 or less was 66.4%. At the seventh, fourteenth, and forty-fifth day and at the second, fourth, and sixth months postpartum, the exclusive breastfeeding rates were 88.5, 78.5, 57.6, 43.1, 32.9, and27.0%, respectively. Comparison of the 6-month exclusive breastfeeding rates between teenage mothers and mothers 20 years ofage or older were not statistically significant (pteenage mothers was at 27.0% and had no significant differences from the rates of mothers 20 years of age or more.
Barriers to Exclusive Breastfeeding among Urban Mothers
Directory of Open Access Journals (Sweden)
Lazina Sharmin
2016-05-01
Full Text Available Background: Breastfeeding is the unique source of nutrition and it plays an important role in the growth, development and survival of the infants. The initiation of breastfeeding within one hour and continuation of only breast milk up to six months ensure maximum benefits. The prevalence of exclusive breastfeeding in Bangladesh is 56% which is low. We designed this study to find out the factors influencing the duration of breastfeeding in Bangladeshi population. Objective: To study the factors influencing noncompliance to exclusive breastfeeding. Materials and Methods: This cross sectional study was conducted in Dhaka Shishu Hospital during the period January to June 2011. It includes 125 infant (1–12 months-mother pairs randomly selected from the inpatient and outpatient departments of Dhaka Shishu Hospital. Mother-infant pairs were divided into two groups based on continuation of only breastfeeding up to six months. Outcomes were compared between two groups. Results: In this study exclusive breastfeeding was found in 27.2% and nonexclusive breastfeeding was in 72.8% cases. It was found that in most cases (40% termination of breastfeeding was at 3--4 months. The study revealed that insufficient milk production due to poor position and attachment, social factors such as influence of husband and other family members, joining to service etc act as barrier to exclusive breastfeeding. Mass media and advice from health professionals had a higher influence on lower rate of exclusive breastfeeding. Women who were multiparous, housewives were more likely to maintain optimal breastfeeding. Conclusion: The present study reveals some important factors contributing to low rate of exclusive breastfeeding in Bangladesh.
Lambda Polarization in Exclusive Electro- and Photoproduction at CLAS
International Nuclear Information System (INIS)
Mestayer, M.D.
2003-01-01
The CLAS collaboration at JLab has recent results on Λ polarization for both electroproduction and photoproduction of K + Λ exclusive states. I note the striking phenomenological trends in the data and discuss the underlying physics which might give rise to these phenomena; both in the context of an e.ective Lagrangian formalism, where the degrees of freedom are intermediate mesons and baryons, and also in the context of a simple quark picture. The quark model argument leads to the conclusion that the s and (bar s) quarks are produced with spins anti-aligned, in apparent contradiction to the popular 3 P 0 model of quark pair creation in which the pair is created with vacuum quantum numbers (J=0 and positive parity), i.e. in an S=1, L=1, J=0 angular momentum state
Totally asymmetric exclusion processes with particles of arbitrary size
Lakatos, G
2003-01-01
The steady-state currents and densities of a one-dimensional totally asymmetric exclusion process (TASEP) with particles that occlude an integer number (d) of lattice sites are computed using various mean-field approximations and Monte Carlo simulations. TASEPs featuring particles of arbitrary size are relevant for modelling systems such as mRNA translation, vesicle locomotion along microtubules and protein sliding along DNA. We conjecture that the nonequilibrium steady-state properties separate into low-density, high-density, and maximal current phases similar to those of the standard (d = 1) TASEP. A simple mean-field approximation for steady-state particle currents and densities is found to be inaccurate. However, we find local equilibrium particle distributions derived from a discrete Tonks gas partition function yield apparently exact currents within the maximal current phase. For the boundary-limited phases, the equilibrium Tonks gas distribution cannot be used to predict currents, phase boundaries, or ...
Information technology made simple
Carter, Roger
1991-01-01
Information Technology: Made Simple covers the full range of information technology topics, including more traditional subjects such as programming languages, data processing, and systems analysis. The book discusses information revolution, including topics about microchips, information processing operations, analog and digital systems, information processing system, and systems analysis. The text also describes computers, computer hardware, microprocessors, and microcomputers. The peripheral devices connected to the central processing unit; the main types of system software; application soft
Modern mathematics made simple
Murphy, Patrick
1982-01-01
Modern Mathematics: Made Simple presents topics in modern mathematics, from elementary mathematical logic and switching circuits to multibase arithmetic and finite systems. Sets and relations, vectors and matrices, tesselations, and linear programming are also discussed.Comprised of 12 chapters, this book begins with an introduction to sets and basic operations on sets, as well as solving problems with Venn diagrams. The discussion then turns to elementary mathematical logic, with emphasis on inductive and deductive reasoning; conjunctions and disjunctions; compound statements and conditional
2013-09-11
... DEPARTMENT OF DEFENSE Department of the Army Notice of Intent To Grant an Exclusive, Partially..., 2012 Entitled ''Tie-Down and Jack Fitting Assembly for Helicopter'' AGENCY: Department of the Army, [email protected]us.army.mil . SUPPLEMENTARY INFORMATION: The patent application relates to the aviation platforms...
Exclusive B Decays to Charmonium Final States
Energy Technology Data Exchange (ETDEWEB)
Barrera, Barbara
2000-10-13
We report on exclusive decays of B mesons into final states containing charmonium using data collected with the BABAR detector at the PEP-II storage rings. The charmonium states considered here are J/{psi}, {psi}(2S), and {chi}{sub c1}. Branching fractions for several exclusive final states, a measurement of the decay amplitudes for the B{sup 0} {yields} J/{psi} K* decay, and measurements of the B{sup 0} and B{sup +} masses are presented. All of the results we present here are preliminary.
Exclusive hadronic and nuclear processes in QCD
International Nuclear Information System (INIS)
Brodsky, S.J.
1985-12-01
Hadronic and nuclear processes are covered, in which all final particles are measured at large invariant masses compared with each other, i.e., large momentum transfer exclusive reactions. Hadronic wave functions in QCD and QCD sum rule constraints on hadron wave functions are discussed. The question of the range of applicability of the factorization formula and perturbation theory for exclusive processes is considered. Some consequences of quark and gluon degrees of freedom in nuclei are discussed which are outside the usual domain of traditional nuclear physics. 44 refs., 7 figs
Exclusion Statistics in Conformal Field Theory Spectra
International Nuclear Information System (INIS)
Schoutens, K.
1997-01-01
We propose a new method for investigating the exclusion statistics of quasiparticles in conformal field theory (CFT) spectra. The method leads to one-particle distribution functions, which generalize the Fermi-Dirac distribution. For the simplest SU(n) invariant CFTs we find a generalization of Gentile parafermions, and we obtain new distributions for the simplest Z N -invariant CFTs. In special examples, our approach reproduces distributions based on 'fractional exclusion statistics' in the sense of Haldane. We comment on applications to fractional quantum Hall effect edge theories. copyright 1997 The American Physical Society
SIMPLE ESTIMATOR AND CONSISTENT STRONGLY OF STABLE DISTRIBUTIONS
Directory of Open Access Journals (Sweden)
Cira E. Guevara Otiniano
2016-06-01
Full Text Available Stable distributions are extensively used to analyze earnings of financial assets, such as exchange rates and stock prices assets. In this paper we propose a simple and strongly consistent estimator for the scale parameter of a symmetric stable L´evy distribution. The advantage of this estimator is that your computational time is minimum thus it can be used to initialize intensive computational procedure such as maximum likelihood. With random samples of sized n we tested the efficacy of these estimators by Monte Carlo method. We also included applications for three data sets.
Lu, Dianchen; Seadawy, Aly R.; Ali, Asghar
2018-06-01
In this current work, we employ novel methods to find the exact travelling wave solutions of Modified Liouville equation and the Symmetric Regularized Long Wave equation, which are called extended simple equation and exp(-Ψ(ξ))-expansion methods. By assigning the different values to the parameters, different types of the solitary wave solutions are derived from the exact traveling wave solutions, which shows the efficiency and precision of our methods. Some solutions have been represented by graphical. The obtained results have several applications in physical science.
Exclusive breastfeedingand postnatal changes in maternal ...
African Journals Online (AJOL)
To evaluate the impact of exclusive breastfeeding (EBFing) practice on maternal anthropometry during the first 6months of birth. Measurement of weight, height, triceps skin-fold thickness (TST), and mid-arm circumference (MAC) was carried out in a matched cohort of women practicing EBFing and those using other ...
Determinants of exclusive breastfeeding practices in Ethiopia ...
African Journals Online (AJOL)
Background: Despite the demonstrated benefits of breast milk, the prevalence of breastfeeding, in-particular exclusive breastfeeding (EBF), in many developing countries including Ethiopia is lower than the international recommendation of EBF for the first six months of life. Objective: To assess the practice of EBF and ...
2010-07-01
... treatment of domestic sewage in a treatment works. (i) Drinking water treatment sludge. This part does not... water or ground water used for drinking water. (j) Commercial and industrial septage. This part does not... DISPOSAL OF SEWAGE SLUDGE General Provisions § 503.6 Exclusions. (a) Treatment processes. This part does...
Sexism and Permanent Exclusion from School
Carlile, Anna
2009-01-01
Focussing on narratives collected during a two year participant observation research project in the children's services department of an urban local authority, this article addresses the intersection between incidents of permanent exclusion from school and assumptions made on the basis of a young person's gender. The article considers gendered…
Knowledge, Attitude and Practice Towards Exclusive Breast ...
African Journals Online (AJOL)
Knowledge, Attitude and Practice Towards Exclusive Breast-Feeding At Jimma, Ethiopia. Teklebrhan Tema. Abstract. No abstract - Available on PDF. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · AJOL African Journals Online. HOW TO USE AJOL.
Exclusive production of W pairs in CMS
INSPIRE-00002838
2014-01-01
We report the results on the search for exclusive production of $W$ pairs in the LHC with data collected by the Compact Muon Solenoid detector in proton-proton collisions at $\\sqrt{s}$~=~7~TeV. The analysis comprises the two-photon production of a $W$ pairs, ${pp\\to p\\,W^{+}W^{-}\\,p\\to p\\,\
Exclusive processes in pp collisions in CMS
Da Silveira, Gustavo Gil
2013-01-01
We report the results on the searches of exclusive production of low- and high-mass pairs with the Compact Muon Solenoid (CMS) detector in proton-proton collisions at $\\sqrt{s}$ = 7 TeV. The analyses comprise the central exclusive $\\gamma\\gamma$ production, the exclusive two-photon production of dileptons, $e^{+}e^{-}$ and $\\mu^{+}\\mu^{-}$, and the exclusive two-photon production of $W$ pairs in the asymmetric $e^{\\pm}\\mu^{\\mp}$ decay channel. No diphotons candidates are observed in data and an upper limit on the cross section is set to 1.18 pb with 95% confidence level for $E_{T}(\\gamma)>$ 5.5 GeV and $|\\eta(\\gamma)|$ 5.5 GeV and $|\\eta(e)|$ 11.5 GeV, $p_{\\textrm{T}}(\\mu)>$ 4 GeV and $|\\eta(\\mu)|$ 4 GeV, $|\\eta(\\mu)|$ 20 GeV. Moreover, the study of the tail of the dilepton transverse momentum distribution resulted in model-independent upper limits for the anomalous quartic gauge couplings, which are of the order of 10$^{-4}$.
Exclusive production of $W$ pairs in CMS
Da Silveira, Gustavo Gil; CMS
2014-01-01
We report the results on the search for exclusive production of $W$ pairs in the LHC with data collected by the Compact Muon Solenoid detector in proton-proton collisions at $\\sqrt{s}$~=~7~TeV. The analysis comprises the two-photon production of a $W$ pairs, ${pp\\to p\\,W^{+}W^{-}\\,p\\to p\\,\
Starvation-free mutual exclusion with semaphores
Hesselink, Wim H.; IJbema, Mark
The standard implementation of mutual exclusion by means of a semaphore allows starvation of processes. Between 1979 and 1986, three algorithms were proposed that preclude starvation. These algorithms use a special kind of semaphore. We model this so-called buffered semaphore rigorously and provide
Deadlocks and dihomotopy in mutual exclusion models
DEFF Research Database (Denmark)
Raussen, Martin
2005-01-01
spaces, the directed ($d$-spaces) of M.Grandis and the flows of P. Gaucher. All models invite to use or modify ideas from algebraic topology, notably homotopy. In specific semaphore models for mutual exclusion, we have developed methods and algorithms that can detect deadlocks and unsafe regions and give...
Counterfactual overdetermination vs. the causal exclusion problem.
Sparber, Georg
2005-01-01
This paper aims to show that a counterfactual approach to causation is not sufficient to provide a solution to the causal exclusion problem in the form of systematic overdetermination. Taking into account the truthmakers of causal counterfactuals provides a strong argument in favour of the identity of causes in situations of translevel, causation.
Factors associated with exclusive breastfeeding among mothers ...
African Journals Online (AJOL)
Conclusion: This study could help mothers, Ministry of Health and other nongovernmental organisations working with child health programmes, in likely interventions and supporting the ongoing child survival programmes, by taking appropriate steps in enhancing exclusive breastfeeding. As mothers attend antenatal and ...
46 CFR 504.4 - Categorical exclusions.
2010-10-01
... FEDERAL MARITIME COMMISSION GENERAL AND ADMINISTRATIVE PROVISIONS PROCEDURES FOR ENVIRONMENTAL POLICY ANALYSIS § 504.4 Categorical exclusions. (a) No environmental analyses need be undertaken or environmental... foreign country. (19) Action taken on special docket applications pursuant to § 502.271 of this chapter...
2010-01-01
... by the Department of Transportation; (d) Activities conducted under the Nuclear Waste Policy Act of... ENERGY NUCLEAR SAFETY MANAGEMENT § 830.2 Exclusions. This part does not apply to: (a) Activities that are regulated through a license by the Nuclear Regulatory Commission (NRC) or a State under an Agreement with...
Testing the exclusivity effect in location memory.
Clark, Daniel P A; Dunn, Andrew K; Baguley, Thom
2013-01-01
There is growing literature exploring the possibility of parallel retrieval of location memories, although this literature focuses primarily on the speed of retrieval with little attention to the accuracy of location memory recall. Baguley, Lansdale, Lines, and Parkin (2006) found that when a person has two or more memories for an object's location, their recall accuracy suggests that only one representation can be retrieved at a time (exclusivity). This finding is counterintuitive given evidence of non-exclusive recall in the wider memory literature. The current experiment explored the exclusivity effect further and aimed to promote an alternative outcome (i.e., independence or superadditivity) by encouraging the participants to combine multiple representations of space at encoding or retrieval. This was encouraged by using anchor (points of reference) labels that could be combined to form a single strongly associated combination. It was hypothesised that the ability to combine the anchor labels would allow the two representations to be retrieved concurrently, generating higher levels of recall accuracy. The results demonstrate further support for the exclusivity hypothesis, showing no significant improvement in recall accuracy when there are multiple representations of a target object's location as compared to a single representation.
Bitcoin and Beyond: Exclusively Informational Money
Bergstra, J.A.; de Leeuw, K.
2013-01-01
The famous new money Bitcoin is classified as a technical informational money (TIM). Besides introducing the idea of a TIM, a more extreme notion of informational money will be developed: exclusively informational money (EXIM). The informational coins (INCOs) of an EXIM can be in control of an agent
Urban violence and exclusion in the DRC
International Development Research Centre (IDRC) Digital Library (Canada)
support, children from impoverished households, many of whom are uneducated, are adding to the ... The goal of this study was to identify the dynamic interplay among poverty/exclusion ... The lack of public lighting and access points to water exposes girls to .... work together to develop more inclusive economic and social.
2010-07-01
... ACCIDENT PREVENTION PROVISIONS Regulated Substances for Accidental Release Prevention § 68.126 Exclusion. Flammable Substances Used as Fuel or Held for Sale as Fuel at Retail Facilities. A flammable substance... substance is used as a fuel or held for sale as a fuel at a retail facility. [65 FR 13250, Mar. 13, 2000] ...
The Exclusive Pursuit of Social Inclusion
Goodson, Ivor
2005-01-01
Despite its best intentions, social exclusion has grown rather than diminished under New Labour's education policies. In order to understand this, Ivor Goodson argues that we need to engage with the history of the formal curriculum and the long and continuing fight over what counts as proper knowledge. Taking science and environmental science as…
27 CFR 8.51 - Exclusion, in general.
2010-04-01
..., DEPARTMENT OF THE TREASURY LIQUORS EXCLUSIVE OUTLETS Exclusion § 8.51 Exclusion, in general. (a) Exclusion, in whole or in part occurs: (1) When a practice by an industry member, whether direct, indirect, or... tie or link between the industry member and retailer or by any other means of industry member control...
Dimensional analysis made simple
International Nuclear Information System (INIS)
Lira, Ignacio
2013-01-01
An inductive strategy is proposed for teaching dimensional analysis to second- or third-year students of physics, chemistry, or engineering. In this strategy, Buckingham's theorem is seen as a consequence and not as the starting point. In order to concentrate on the basics, the mathematics is kept as elementary as possible. Simple examples are suggested for classroom demonstrations of the power of the technique and others are put forward for homework or experimentation, but instructors are encouraged to produce examples of their own. (paper)
Applied mathematics made simple
Murphy, Patrick
1982-01-01
Applied Mathematics: Made Simple provides an elementary study of the three main branches of classical applied mathematics: statics, hydrostatics, and dynamics. The book begins with discussion of the concepts of mechanics, parallel forces and rigid bodies, kinematics, motion with uniform acceleration in a straight line, and Newton's law of motion. Separate chapters cover vector algebra and coplanar motion, relative motion, projectiles, friction, and rigid bodies in equilibrium under the action of coplanar forces. The final chapters deal with machines and hydrostatics. The standard and conte
Wooldridge, Susan
2013-01-01
Data Processing: Made Simple, Second Edition presents discussions of a number of trends and developments in the world of commercial data processing. The book covers the rapid growth of micro- and mini-computers for both home and office use; word processing and the 'automated office'; the advent of distributed data processing; and the continued growth of database-oriented systems. The text also discusses modern digital computers; fundamental computer concepts; information and data processing requirements of commercial organizations; and the historical perspective of the computer industry. The
Deane, Sharon
2003-01-01
ASP Made Simple provides a brief introduction to ASP for the person who favours self teaching and/or does not have expensive computing facilities to learn on. The book will demonstrate how the principles of ASP can be learned with an ordinary PC running Personal Web Server, MS Access and a general text editor like Notepad.After working through the material readers should be able to:* Write ASP scripts that can display changing information on a web browser* Request records from a remote database or add records to it* Check user names & passwords and take this knowledge forward, either for their
Hansen, Jean-Pierre
1986-01-01
This book gives a comprehensive and up-to-date treatment of the theory of ""simple"" liquids. The new second edition has been rearranged and considerably expanded to give a balanced account both of basic theory and of the advances of the past decade. It presents the main ideas of modern liquid state theory in a way that is both pedagogical and self-contained. The book should be accessible to graduate students and research workers, both experimentalists and theorists, who have a good background in elementary mechanics.Key Features* Compares theoretical deductions with experimental r
Leibo, Joel Z.; Liao, Qianli; Freiwald, Winrich A.; Anselmi, Fabio; Poggio, Tomaso
2017-01-01
SUMMARY The primate brain contains a hierarchy of visual areas, dubbed the ventral stream, which rapidly computes object representations that are both specific for object identity and robust against identity-preserving transformations like depth-rotations [1, 2]. Current computational models of object recognition, including recent deep learning networks, generate these properties through a hierarchy of alternating selectivity-increasing filtering and tolerance-increasing pooling operations, similar to simple-complex cells operations [3, 4, 5, 6]. Here we prove that a class of hierarchical architectures and a broad set of biologically plausible learning rules generate approximate invariance to identity-preserving transformations at the top level of the processing hierarchy. However, all past models tested failed to reproduce the most salient property of an intermediate representation of a three-level face-processing hierarchy in the brain: mirror-symmetric tuning to head orientation [7]. Here we demonstrate that one specific biologically-plausible Hebb-type learning rule generates mirror-symmetric tuning to bilaterally symmetric stimuli like faces at intermediate levels of the architecture and show why it does so. Thus the tuning properties of individual cells inside the visual stream appear to result from group properties of the stimuli they encode and to reflect the learning rules that sculpted the information-processing system within which they reside. PMID:27916522
International Nuclear Information System (INIS)
Khamlich, S.; Abdullaeva, Z.; Kennedy, J.V.; Maaza, M.
2017-01-01
Highlights: • A symmetric supercapacitor device based on NiF-G/ZHCNs composite materials electrodes was successfully fabricated. • The fabricated device exhibited high specific areal capacitance of 222 mF cm"−"2 at 1.0 mA cm"−"2 current density. • Excellent cycling performance with 96% specific capacitance retention after 5000 cycles was achieved. - Abstract: In this work, zinc hydroxychloride nanosheets (ZHCNs) were deposited on 3d graphene-nickel foam (NiF-G) by employing a simple hydrothermal synthesis method to form NiF-G/ZHCNs composite electrode materials. The fabricated NiF-G/ZHCNs electrode revealed a well-developed pore structures with high specific surface area of 119 m"2 g"−"1, and used as electrode materials for symmetric supercapacitor with aqueous alkaline electrolyte. The specific areal capacitance and electron charge transfer resistance (R_c_t) were 222 mF cm"−"2 (at current density of 1.0 mA cm"−"2) and 1.63 Ω, respectively, in a symmetric two-electrode system. After 5000 cycles with galvanostatic charge/discharge, the device can maintain 96% of its initial capacitance under 1.0 mA cm"−"2 and showed low R_c_t of about 9.84 Ω. These results indicate that NiF-G/ZHCNs composite is an excellent electrode material for electrochemical energy storage devices.
Probabilistic simple sticker systems
Selvarajoo, Mathuri; Heng, Fong Wan; Sarmin, Nor Haniza; Turaev, Sherzod
2017-04-01
A model for DNA computing using the recombination behavior of DNA molecules, known as a sticker system, was introduced by by L. Kari, G. Paun, G. Rozenberg, A. Salomaa, and S. Yu in the paper entitled DNA computing, sticker systems and universality from the journal of Acta Informatica vol. 35, pp. 401-420 in the year 1998. A sticker system uses the Watson-Crick complementary feature of DNA molecules: starting from the incomplete double stranded sequences, and iteratively using sticking operations until a complete double stranded sequence is obtained. It is known that sticker systems with finite sets of axioms and sticker rules generate only regular languages. Hence, different types of restrictions have been considered to increase the computational power of sticker systems. Recently, a variant of restricted sticker systems, called probabilistic sticker systems, has been introduced [4]. In this variant, the probabilities are initially associated with the axioms, and the probability of a generated string is computed by multiplying the probabilities of all occurrences of the initial strings in the computation of the string. Strings for the language are selected according to some probabilistic requirements. In this paper, we study fundamental properties of probabilistic simple sticker systems. We prove that the probabilistic enhancement increases the computational power of simple sticker systems.
Schilstra, Maria J; Martin, Stephen R
2009-01-01
Stochastic simulations may be used to describe changes with time of a reaction system in a way that explicitly accounts for the fact that molecules show a significant degree of randomness in their dynamic behavior. The stochastic approach is almost invariably used when small numbers of molecules or molecular assemblies are involved because this randomness leads to significant deviations from the predictions of the conventional deterministic (or continuous) approach to the simulation of biochemical kinetics. Advances in computational methods over the three decades that have elapsed since the publication of Daniel Gillespie's seminal paper in 1977 (J. Phys. Chem. 81, 2340-2361) have allowed researchers to produce highly sophisticated models of complex biological systems. However, these models are frequently highly specific for the particular application and their description often involves mathematical treatments inaccessible to the nonspecialist. For anyone completely new to the field to apply such techniques in their own work might seem at first sight to be a rather intimidating prospect. However, the fundamental principles underlying the approach are in essence rather simple, and the aim of this article is to provide an entry point to the field for a newcomer. It focuses mainly on these general principles, both kinetic and computational, which tend to be not particularly well covered in specialist literature, and shows that interesting information may even be obtained using very simple operations in a conventional spreadsheet.
Nonstandard jump functions for radically symmetric shock waves
International Nuclear Information System (INIS)
Baty, Roy S.; Tucker, Don H.; Stanescu, Dan
2008-01-01
Nonstandard analysis is applied to derive generalized jump functions for radially symmetric, one-dimensional, magnetogasdynamic shock waves. It is assumed that the shock wave jumps occur on infinitesimal intervals and the jump functions for the physical parameters occur smoothly across these intervals. Locally integrable predistributions of the Heaviside function are used to model the flow variables across a shock wave. The equations of motion expressed in nonconservative form are then applied to derive unambiguous relationships between the jump functions for the physical parameters for two families of self-similar flows. It is shown that the microstructures for these families of radially symmetric, magnetogasdynamic shock waves coincide in a nonstandard sense for a specified density jump function.
Random matrix ensembles for PT-symmetric systems
International Nuclear Information System (INIS)
Graefe, Eva-Maria; Mudute-Ndumbe, Steve; Taylor, Matthew
2015-01-01
Recently much effort has been made towards the introduction of non-Hermitian random matrix models respecting PT-symmetry. Here we show that there is a one-to-one correspondence between complex PT-symmetric matrices and split-complex and split-quaternionic versions of Hermitian matrices. We introduce two new random matrix ensembles of (a) Gaussian split-complex Hermitian; and (b) Gaussian split-quaternionic Hermitian matrices, of arbitrary sizes. We conjecture that these ensembles represent universality classes for PT-symmetric matrices. For the case of 2 × 2 matrices we derive analytic expressions for the joint probability distributions of the eigenvalues, the one-level densities and the level spacings in the case of real eigenvalues. (fast track communication)
Synthesis of novel symmetrical macrocycle via oxidative homocoupling of bisalkyne
Energy Technology Data Exchange (ETDEWEB)
Kamalulazmy, Nurulain; Hassan, Nurul Izzaty [School of Chemical Sciences and Food Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor Darul Ehsan (Malaysia)
2014-09-03
A novel symmetrical macrocycle has been synthesised via oxidative homocoupling of bisalkyne, diprop-2-ynyl pyridine-2,6-dicarboxylate mediated by copper (I) iodide (CuI) and 4-dimethylaminopyridine (DMAP). The precursor compound was synthesised from 2,6-pyridine dicarbonyl dichloride and propargyl alcohol in the presence of triethylamine. The reaction mixture was stirred overnight and further purified via column chromatograpy with 76% yield. Single crystal for X-ray study was obtained by recrystallization from acetone. Subsequently, a symmetrical macrocycle was synthesised from oxidative homocoupling of precursor compound in open atmosphere. The crude product was purified by column chromatography to furnish macrocycle compound with 5% yield. Both compounds were characterised by IR, {sup 1}H and {sup 13}C NMR and mass spectral techniques. The unusual conformation of the bisalkyne and twisted conformation of designed macrocycle has influence the percentage yield. This has been studied thoroughly by X-ray crystallography and electronic structure calculations.
Information Retrieval and Criticality in Parity-Time-Symmetric Systems.
Kawabata, Kohei; Ashida, Yuto; Ueda, Masahito
2017-11-10
By investigating information flow between a general parity-time (PT-)symmetric non-Hermitian system and an environment, we find that the complete information retrieval from the environment can be achieved in the PT-unbroken phase, whereas no information can be retrieved in the PT-broken phase. The PT-transition point thus marks the reversible-irreversible criticality of information flow, around which many physical quantities such as the recurrence time and the distinguishability between quantum states exhibit power-law behavior. Moreover, by embedding a PT-symmetric system into a larger Hilbert space so that the entire system obeys unitary dynamics, we reveal that behind the information retrieval lies a hidden entangled partner protected by PT symmetry. Possible experimental situations are also discussed.
Symmetrical and overloaded effect of diffusion in information filtering
Zhu, Xuzhen; Tian, Hui; Chen, Guilin; Cai, Shimin
2017-10-01
In physical dynamics, mass diffusion theory has been applied to design effective information filtering models on bipartite network. In previous works, researchers unilaterally believe objects' similarities are determined by single directional mass diffusion from the collected object to the uncollected, meanwhile, inadvertently ignore adverse influence of diffusion overload. It in some extent veils the essence of diffusion in physical dynamics and hurts the recommendation accuracy and diversity. After delicate investigation, we argue that symmetrical diffusion effectively discloses essence of mass diffusion, and high diffusion overload should be published. Accordingly, in this paper, we propose an symmetrical and overload penalized diffusion based model (SOPD), which shows excellent performances in extensive experiments on benchmark datasets Movielens and Netflix.
EXCEPTIONAL POINTS IN OPEN AND PT-SYMMETRIC SYSTEMS
Directory of Open Access Journals (Sweden)
Hichem Eleuch
2014-04-01
Full Text Available Exceptional points (EPs determine the dynamics of open quantum systems and cause also PT symmetry breaking in PT symmetric systems. From a mathematical point of view, this is caused by the fact that the phases of the wavefunctions (eigenfunctions of a non-Hermitian Hamiltonian relative to one another are not rigid when an EP is approached. The system is therefore able to align with the environment to which it is coupled and, consequently, rigorous changes of the system properties may occur. We compare analytically as well as numerically the eigenvalues and eigenfunctions of a 2 × 2 matrix that is characteristic either of open quantum systems at high level density or of PT symmetric optical lattices. In both cases, the results show clearly the influence of the environment on the system in the neighborhood of EPs. Although the systems are very different from one another, the eigenvalues and eigenfunctions indicate the same characteristic features.
Biophysical information in asymmetric and symmetric diurnal bidirectional canopy reflectance
Vanderbilt, Vern C.; Caldwell, William F.; Pettigrew, Rita E.; Ustin, Susan L.; Martens, Scott N.; Rousseau, Robert A.; Berger, Kevin M.; Ganapol, B. D.; Kasischke, Eric S.; Clark, Jenny A.
1991-01-01
The authors present a theory for partitioning the information content in diurnal bidirectional reflectance measurements in order to detect differences potentially related to biophysical variables. The theory, which divides the canopy reflectance into asymmetric and symmetric functions of solar azimuth angle, attributes asymmetric variation to diurnal changes in the canopy biphysical properties. The symmetric function is attributed to the effects of sunlight interacting with a hypothetical average canopy which would display the average diurnal properties of the actual canopy. The authors analyzed radiometer data collected diurnally in the Thematic Mapper wavelength bands from two walnut canopies that received differing irrigation treatments. The reflectance of the canopies varied with sun and view angles and across seven bands in the visible, near-infrared, and middle infrared wavelength regions. Although one of the canopies was permanently water stressed and the other was stressed in mid-afternoon each day, no water stress signature was unambiguously evident in the reflectance data.
Implications of the Cosmological Constant for Spherically Symmetric Mass Distributions
Zubairi, Omair; Weber, Fridolin
2013-04-01
In recent years, scientists have made the discovery that the expansion rate of the Universe is increasing rather than decreasing. This acceleration leads to an additional term in Albert Einstein's field equations which describe general relativity and is known as the cosmological constant. This work explores the aftermath of a non-vanishing cosmological constant for relativistic spherically symmetric mass distributions, which are susceptible to change against Einstein's field equations. We introduce a stellar structure equation known as the Tolman-Oppenhiemer-Volkoff (TOV) equation modified for a cosmological constant, which is derived from Einstein's modified field equations. We solve this modified TOV equation for these spherically symmetric mass distributions and obtain stellar properties such as mass and radius and investigate changes that may occur depending on the value of the cosmological constant.
Maximal slicing of D-dimensional spherically symmetric vacuum spacetime
International Nuclear Information System (INIS)
Nakao, Ken-ichi; Abe, Hiroyuki; Yoshino, Hirotaka; Shibata, Masaru
2009-01-01
We study the foliation of a D-dimensional spherically symmetric black-hole spacetime with D≥5 by two kinds of one-parameter families of maximal hypersurfaces: a reflection-symmetric foliation with respect to the wormhole slot and a stationary foliation that has an infinitely long trumpetlike shape. As in the four-dimensional case, the foliations by the maximal hypersurfaces avoid the singularity irrespective of the dimensionality. This indicates that the maximal slicing condition will be useful for simulating higher-dimensional black-hole spacetimes in numerical relativity. For the case of D=5, we present analytic solutions of the intrinsic metric, the extrinsic curvature, the lapse function, and the shift vector for the foliation by the stationary maximal hypersurfaces. These data will be useful for checking five-dimensional numerical-relativity codes based on the moving puncture approach.
Thermal properties of self-gravitating plane-symmetric configuration
Energy Technology Data Exchange (ETDEWEB)
Hara, T; Ikeuchi, S [Kyoto Univ. (Japan). Dept. of Physics; Sugimoto, D
1976-09-01
As a limiting case of rotating stars, thermal properties of infinite plane-symmetric self-gravitating gas are investigated. Such a configuration is characterized by surface density of the plane instead of stellar mass. In the Kelvin contraction, temperature of the interior decreases, if the surface density is kept constant. If the accretion of matter takes place, or if the angular momenta are transferred outward, the surface density will increase. In this case, the temperature of the interior may increase. When a nuclear burning is ignited, it is thermally unstable in most cases, even when electrons are non-degenerate. This thermal instability is one of the essential differences of the plane-symmetric configuration from the spherical star. Such instabilities are computed for different cases of nuclear fuels. This type of nuclear instability is the same phenomenon as thermal instability of a thin shell burning in a spherical star.
Continuous symmetric reductions of the Adler-Bobenko-Suris equations
International Nuclear Information System (INIS)
Tsoubelis, D; Xenitidis, P
2009-01-01
Continuously symmetric solutions of the Adler-Bobenko-Suris class of discrete integrable equations are presented. Initially defined by their invariance under the action of both of the extended three-point generalized symmetries admitted by the corresponding equations, these solutions are shown to be determined by an integrable system of partial differential equations. The connection of this system to the Nijhoff-Hone-Joshi 'generating partial differential equations' is established and an auto-Baecklund transformation and a Lax pair for it are constructed. Applied to the H1 and Q1 δ=0 members of the Adler-Bobenko-Suris family, the method of continuously symmetric reductions yields explicit solutions determined by the Painleve trancendents
Exotic fermions in the left-right symmetric model
International Nuclear Information System (INIS)
Choi, J.; Volkas, R.R.
1992-01-01
A systematic study is made of non-standard fermion multiplets in left-right symmetric models with gauge group SU(3) x SU(2) L x SU(2) R x U(1) BL . Constraints from gauge anomaly cancellation and invariance of Yukawa coupling terms are used to define interesting classes of exotic fermions. The standard quark lepton spectrum of left-right symmetric models was identified as the simplest member of an infinite class. Phenomenological implications of the next simplest member of this class are then studied. Classes of exotic fermions which may couple to the standard fermions through doublet Higgs bosons were also considered, then shown that some of these exotics may be used to induce a generalised universal see-saw mechanism. 12 refs., 1 tab
Long-term repetition priming with symmetrical polygons and words.
Kersteen-Tucker, Z
1991-01-01
In two different tasks, subjects were asked to make lexical decisions (word or nonword) and symmetry judgments (symmetrical or nonsymmetrical) about two-dimensional polygons. In both tasks, every stimulus was repeated at one of four lags (0, 1, 4, or 8 items interposed between the first and second stimulus presentations). This paradigm, known as repetition priming, revealed comparable short-term priming (Lag 0) and long-term priming (Lags 1, 4, and 8) both for symmetrical polygons and for words. A shorter term component (Lags 0 and 1) of priming was observed for nonwords, and only very short-term priming (Lag 0) was observed for nonsymmetrical polygons. These results indicate that response facilitation accruing from repeated exposure can be observed for stimuli that have no preexisting memory representations and suggest that perceptual factors contribute to repetition-priming effects.
Admissible perturbations and false instabilities in PT -symmetric quantum systems
Znojil, Miloslav
2018-03-01
One of the most characteristic mathematical features of the PT -symmetric quantum mechanics is the explicit Hamiltonian dependence of its physical Hilbert space of states H =H (H ) . Some of the most important physical consequences are discussed, with emphasis on the dynamical regime in which the system is close to phase transition. Consistent perturbation treatment of such a regime is proposed. An illustrative application of the innovated perturbation theory to a non-Hermitian but PT -symmetric user-friendly family of J -parametric "discrete anharmonic" quantum Hamiltonians H =H (λ ⃗) is provided. The models are shown to admit the standard probabilistic interpretation if and only if the parameters remain compatible with the reality of the spectrum, λ ⃗∈D(physical ) . In contradiction to conventional wisdom, the systems are then shown to be stable with respect to admissible perturbations, inside the domain D(physical ), even in the immediate vicinity of the phase-transition boundaries ∂ D(physical ) .
PT-symmetric ladders with a scattering core
Energy Technology Data Exchange (ETDEWEB)
D' Ambroise, J. [Department of Mathematics, Amherst College, Amherst, MA 01002-5000 (United States); Lepri, S. [CNR – Consiglio Nazionale delle Ricerche, Istituto dei Sistemi Complessi, via Madonna del piano 10, I-50019 Sesto Fiorentino (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Italy); Malomed, B.A. [Department of Physical Electronics, School of Electrical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv 69978 (Israel); Kevrekidis, P.G. [Department of Mathematics and Statistics, University of Massachusetts, Amherst, MA 01003-9305 (United States)
2014-08-01
We consider a PT-symmetric chain (ladder-shaped) system governed by the discrete nonlinear Schrödinger equation where the cubic nonlinearity is carried solely by two central “rungs” of the ladder. Two branches of scattering solutions for incident plane waves are found. We systematically construct these solutions, analyze their stability, and discuss non-reciprocity of the transmission associated with them. To relate the results to finite-size wavepacket dynamics, we also perform direct simulations of the evolution of the wavepackets, which confirm that the transmission is indeed asymmetric in this nonlinear system with the mutually balanced gain and loss. - Highlights: • We model a PT-symmetric ladder system with cubic nonlinearity on two central rungs. • We examine non-reciprocity and stability of incident plane waves. • Simulations of wavepackets confirm our results.
The inverse spatial Laplacian of spherically symmetric spacetimes
International Nuclear Information System (INIS)
Fernandes, Karan; Lahiri, Amitabha
2017-01-01
We derive the inverse spatial Laplacian for static, spherically symmetric backgrounds by solving Poisson’s equation for a point source. This is different from the electrostatic Green function, which is defined on the four dimensional static spacetime, while the equation we consider is defined on the spatial hypersurface of such spacetimes. This Green function is relevant in the Hamiltonian dynamics of theories defined on spherically symmetric backgrounds, and closed form expressions for the solutions we find are absent in the literature. We derive an expression in terms of elementary functions for the Schwarzschild spacetime, and comment on the relation of this solution with the known Green function of the spacetime Laplacian operator. We also find an expression for the Green function on the static pure de-Sitter space in terms of hypergeometric functions. We conclude with a discussion of the constraints of the electromagnetic field. (paper)
Entanglement of polar symmetric top molecules as candidate qubits.
Wei, Qi; Kais, Sabre; Friedrich, Bretislav; Herschbach, Dudley
2011-10-21
Proposals for quantum computing using rotational states of polar molecules as qubits have previously considered only diatomic molecules. For these the Stark effect is second-order, so a sizable external electric field is required to produce the requisite dipole moments in the laboratory frame. Here we consider use of polar symmetric top molecules. These offer advantages resulting from a first-order Stark effect, which renders the effective dipole moments nearly independent of the field strength. That permits use of much lower external field strengths for addressing sites. Moreover, for a particular choice of qubits, the electric dipole interactions become isomorphous with NMR systems for which many techniques enhancing logic gate operations have been developed. Also inviting is the wider chemical scope, since many symmetric top organic molecules provide options for auxiliary storage qubits in spin and hyperfine structure or in internal rotation states. © 2011 American Institute of Physics
Ltaief, Hatem; Luszczek, Piotr R.; Haidar, Azzam; Dongarra, Jack
2012-01-01
This paper proposes an efficient implementation of the generalized symmetric eigenvalue problem on multicore architecture. Based on a four-stage approach and tile algorithms, the original problem is first transformed into a standard symmetric
Complex group algebras of the double covers of the symmetric and alternating group
DEFF Research Database (Denmark)
Bessenrodt, Christine; Nguyen, Hung Ngoc; Olsson, Jørn Børling
2015-01-01
We prove that the double covers of the alternating and symmetric groups are determined by their complex group algebras......We prove that the double covers of the alternating and symmetric groups are determined by their complex group algebras...
Non-Abelian behavior of α bosons in cold symmetric nuclear matter
International Nuclear Information System (INIS)
Zheng Hua; Bonasera, Aldo
2011-01-01
The ground-state energy of infinite symmetric nuclear matter is usually described by strongly interacting nucleons obeying the Pauli exclusion principle. We can imagine a unitary transformation which groups four nonidentical nucleons (i.e., with different spin and isospin) close in coordinate space. Those nucleons, being nonidentical, do not obey the Pauli principle, thus their relative momenta are negligibly small (just to fulfill the Heisenberg principle). Such a cluster can be identified with an α boson. But in dense nuclear matter, those α particles still obey the Pauli principle since are constituted of fermions. The ground state energy of nuclear matter α clusters is the same as for nucleons, thus it is degenerate. We could think of α particles as vortices which can now braid, for instance making 8 Be which leave the ground state energy unchanged. Further braiding to heavier clusters ( 12 C, 16 O,...) could give a different representation of the ground state at no energy cost. In contrast d-like clusters (i.e., N=Z odd-odd nuclei, where N and Z are the neutron and proton number, respectively) cannot describe the ground state of nuclear matter and can be formed at high excitation energies (or temperatures) only. We show that even-even, N=Z, clusters could be classified as non-Abelian states of matter. As a consequence an α condensate in nuclear matter might be hindered by the Fermi motion, while it could be possible a condensate of 8 Be or heavier clusters.
Identifying compatibility of lithium salts with LiFePO4 cathode using a symmetric cell
Tong, Bo; Wang, Jiawei; Liu, Zhenjie; Ma, Lipo; Zhou, Zhibin; Peng, Zhangquan
2018-04-01
The electrochemical performance of lithium-ion batteries is dominated by the interphase electrochemistry between the electrolyte and electrode materials. A multitude of efforts have been dedicated to the solid electrolyte interphase (SEI) formed on the anode. However, the interphase on the cathode, namely the cathode electrolyte interphase (CEI), is left aside, partially due to the fact that it is hard to single out the CEI considering the complicated anode-cathode inter-talk. Herein, a partially delithiated lithium iron phosphate (Li0.25FePO4) electrode is used as the anode. Owing to a high voltage plateau (≈3.45 V vs. Li/Li+), negligible reduction reactions of electrolyte occur on the L0.25FePO4 anode. Therefore, the CEI can be investigated exclusively. Using a LiFePO4|Li0.25FePO4 symmetric cell configuration, we scrutinize the compatibility of the electrolytes containing a wide spectrum of lithium salts, Li[(FSO2)(Cm F2m+1SO2)N] (m = 0, 1, 2, 4), with the LiFePO4, in both cycling and calendar tests. It is found that the Li[(FSO2)(n-C4F9SO2)N] (LiFNFSI)-based electrolyte exhibits the highest compatibility with LiFePO4.
Procrustes Problems for General, Triangular, and Symmetric Toeplitz Matrices
Directory of Open Access Journals (Sweden)
Juan Yang
2013-01-01
Full Text Available The Toeplitz Procrustes problems are the least squares problems for the matrix equation AX=B over some Toeplitz matrix sets. In this paper the necessary and sufficient conditions are obtained about the existence and uniqueness for the solutions of the Toeplitz Procrustes problems when the unknown matrices are constrained to the general, the triangular, and the symmetric Toeplitz matrices, respectively. The algorithms are designed and the numerical examples show that these algorithms are feasible.
Superfield Lax formalism of supersymmetric sigma model on symmetric spaces
International Nuclear Information System (INIS)
Saleem, U.; Hassan, M.
2006-01-01
We present a superfield Lax formalism of the superspace sigma model based on the target space G/H and show that a one-parameter family of flat superfield connections exists if the target space G/H is a symmetric space. The formalism has been related to the existence of an infinite family of local and non-local superfield conserved quantities. A few examples have been given to illustrate the results. (orig.)
Two-parametric PT-symmetric quartic family
International Nuclear Information System (INIS)
Eremenko, Alexandre; Gabrielov, Andrei
2012-01-01
We describe a parametrization of the real spectral locus of the two-parametric family of PT-symmetric quartic oscillators. For this family, we find a parameter region where all eigenvalues are real, extending the results of Dorey et al (2007 J. Phys. A: Math Theor. 40 R205–83) and Shin (2005 J. Phys. A: Math. Gen. 38 6147–66; 2002 Commun. Math. Phys. 229 543–64). (paper)
Quantum cloning of mixed states in symmetric subspaces
International Nuclear Information System (INIS)
Fan Heng
2003-01-01
Quantum-cloning machine for arbitrary mixed states in symmetric subspaces is proposed. This quantum-cloning machine can be used to copy part of the output state of another quantum-cloning machine and is useful in quantum computation and quantum information. The shrinking factor of this quantum cloning achieves the well-known upper bound. When the input is identical pure states, two different fidelities of this cloning machine are optimal
Research on Characteristics of New Energy Dissipation With Symmetrical Structure
Ming, Wen; Huang, Chun-mei; Huang, Hao-wen; Wang, Xin-fang
2018-03-01
Utilizing good energy consumption capacity of arc steel bar, a new energy dissipation with symmetrical structure was proposed in this article. On the base of collection experimental data of damper specimen Under low cyclic reversed loading, finite element models were built by using ANSYS software, and influences of parameter change (Conduction rod diameter, Actuation plate thickness, Diameter of arc steel rod, Curved bars initial bending) on energy dissipation performance were analyzed. Some useful conclusions which can lay foundations for practical application were drawn.
Some problems in operator theory on bounded symmetric domains
Czech Academy of Sciences Publication Activity Database
Engliš, Miroslav
2004-01-01
Roč. 81, č. 1 (2004), s. 51-71 ISSN 0167-8019. [Representations of Lie groups, harmonic analysis on homogeneous spaces and quantization. Leiden, 07.12.2002-13.12.2002] R&D Projects: GA ČR GA201/03/0041 Institutional research plan: CEZ:AV0Z1019905 Keywords : homogeneous multiplication operators * bounded symmetric domains Subject RIV: BA - General Mathematics Impact factor: 0.354, year: 2004
${ \\mathcal P }{ \\mathcal T }$-symmetric interpretation of unstable effective potentials
Bender, Carl M.; Mavromatos, Nick E.; Sarkar, Sarben
2016-01-01
The conventional interpretation of the one-loop effective potentials of the Higgs field in the Standard Model and the gravitino condensate in dynamically broken supergravity is that these theories are unstable at large field values. A ${ \\mathcal P }{ \\mathcal T }$-symmetric reinterpretation of these models at a quantum-mechanical level eliminates these instabilities and suggests that these instabilities may also be tamed at the quantum-field-theory level.
Dp spaces on bounded symmetric domains of Cn
International Nuclear Information System (INIS)
Shi Jihuai.
1989-06-01
In this paper, the space D p (Ω) of functions holomorphic on bounded symmetric domain of C m is defined. We prove that H p (Ω) is contained in D p (Ω) if 0 p (Ω) is contained in H p (Ω) if p ≥2, and both inclusions are proper. Further we find that some theorems on H p (Ω) can be extended to the wider class D p (Ω) for 0 < p ≤ 2. (author). 12 refs
A time-symmetric Universe model and its observational implication
International Nuclear Information System (INIS)
Futamase, T.; Matsuda, T.
1987-01-01
A time-symmetric closed-universe model is discussed in terms of the radiation arrow of time. The time symmetry requires the occurrence of advanced waves in the recontracting phase of the Universe. The observational consequences of such advanced waves are considered, and it is shown that a test observer in the expanding phase can observe a time-reversed image of a source of radiation in the future recontracting phase
Time-symmetric universe model and its observational implication
Energy Technology Data Exchange (ETDEWEB)
Futamase, T.; Matsuda, T.
1987-08-01
A time-symmetric closed-universe model is discussed in terms of the radiation arrow of time. The time symmetry requires the occurrence of advanced waves in the recontracting phase of the Universe. We consider the observational consequences of such advanced waves, and it is shown that a test observer in the expanding phase can observe a time-reversed image of a source of radiation in the future recontracting phase.
Weaving and neural complexity in symmetric quantum states
Susa, Cristian E.; Girolami, Davide
2018-04-01
We study the behaviour of two different measures of the complexity of multipartite correlation patterns, weaving and neural complexity, for symmetric quantum states. Weaving is the weighted sum of genuine multipartite correlations of any order, where the weights are proportional to the correlation order. The neural complexity, originally introduced to characterize correlation patterns in classical neural networks, is here extended to the quantum scenario. We derive closed formulas of the two quantities for GHZ states mixed with white noise.