Using Pi-calculus to Model Dynamic Web Services Composition Based on the Authority Model

There are lots of research works on web service, composition, modeling, verification and other problems. Theses research works are done on the basis of formal methods, such as petri-net, pi-calculus, automata theory, and so on. Pi-calculus is a natural vehicle to model mobility aspect in dynamic web services composition (DWSC). However, it has recently been shown that pi-calculus needs to be extended suitably to specify and verify DWSC. In this paper, we considers the authority model for DWSC, extends pi-calculus in order to model dynamic attributes of system, and proposes a automatic method for modeling DWSC based on extended pi-calculus.Comment: 11 pages, 3 figure

A Condition for Hopf bifurcation to occur in Equations of Lotka - Volterra Type with Delay

It is known that Lotka - Volterra type differential equations with delays or distributed delays have an important role in modeling ecological systems. In this paper we study the effects of distributed delay on the dynamics of the harvested one predator - two prey model. Using the expectation of the distribution of the delay as a bifurcation parameter, we show that the equilibrium that was asymptotic stable becomes unstable and Hopf bifurcation can occur as the expectation crosses some critical values.Comment: 9 pages, in ver 2 added references and conclusion and further study, version 2 is accepted in JTP

Equiaffine Structure and Conjugate Ricci-symmetry of a Statistical Manifold

A condition for a statistical manifold to have an equiaffine structure is studied. The facts that dual flatness and conjugate symmetry of a statistical manifold are sufficient conditions for a statistical manifold to have an equiaffine structure were obtained in [2] and [3]. In this paper, a fact that a statistical manifold, which is conjugate Ricci-symmetric, has an equiaffine structure is given, where conjugate Ricci-symmetry is weaker condition than conjugate symmetry. A condition for conjugate symmetry and conjugate Ricci-symmetry to coincide is also given.Comment: 7 page

Suppression of DC term in Fresnel digital holography by sequence subtraction of holograms

An experimental method for suppression of DC term in the reconstructed images from Fresnel digital holograms is presented. In this method, two holograms for the same object are captured sequentially and subtracted. Since these two holograms are captured at different moments, they are slightly different from each other for fluctuations of noises. The DC term is suppressed in the image reconstructed from the subtraction hologram, while the two virtual and real images are successfully reconstructed. This method can be potentially used for the improvement of image quality reconstructed from Fresnel digital holograms

Computer simulation control of single crystal growth process by melt pulling method

In this paper, on the basis of the set of simplified model state equations to represent the dynamic features of melt pulling method growth process, we constructed a simulation control system of Matlab Simulink and analyzed control features of state variables for the total growth process including shoulder growth process and the constant diameter growth process of single crystals such as Si and LiNbO3.Comment: 22 figures, 7 page

Mixed eldfellite compounds \ce{Na(Fe_{1/2}M_{1/2})(SO4)2} (M = Mn, Co, Ni): A new family of high electrode potential cathodes for the sodium-ion battery

Natural abundance of sodium and its similar behavior to lithium triggered recent extensive studies of cost-effective sodium-ion batteries (SIBs) for large-scale energy storage systems. A challenge is to develop electrode materials with a high electrode potential, specific capacity and a good rate capability. In this work we propose mixed eldfellite compounds \ce{Na_x(Fe_{1/2}M_{1/2})(SO4)2} (M = Mn, Co, Ni) as a new family of high electrode potential cathodes of SIBs and present their material properties predicted by first-principles calculations. The structural optimizations show that these materials have significantly small volume expansion rates below 5\% upon Na insertion/desertion with negative Na binding energies. Through the electronic structure calculations, we find band insulating properties and hole (and/or electron) polaron hoping as a possible mechanism for the charge transfer. Especially we confirm the high electrode voltages over 4 V with reasonably high specific capacities. We also investigate the sodium ion mobility by estimating plausible diffusion pathways and calculating the corresponding activation barriers, demonstrating the reasonably fast migrations of sodium ions during the operation. Our calculation results indicate that these mixed eldfellite compounds can be suitable materials for high performance SIB cathodes

One approach for determining susceptibilities and order parameters in multi-band Hubbard model

We present an approach for determining susceptibilities and order parameters in multi-band Hubbard model within functional renormalization group method, and apply it to study various instabilities of the FeAs-based high temperature superconductor. First, we derive the formulae of susceptibilities and order parameters of superconducting parings, spin density waves and charge density waves with diverse wave vectors which could occur in multi-band Hubbard model. Second, we apply it to the FeAs-based high temperature superconductor and find an electronic-driven superconducting pairing instability within a five band model with pure repulsive interactions. Our study shows that for doping of our concern, there is competition between antiferromagnetic and superconducting instabilities. In addition, we show that for doping of 0.1, the susceptibility of extended s-wave pairing is dominant over others, while a staggered superconducting pairing with has the second largest value of susceptibility

k-Congruences on semirings

For any semiring, the concept of k-congruences is introduced, criteria for k-congruences are established, it is proved that there is an inclusion-preserving bijection between k-congruences and k-ideals, and an equivalent condition for the existence of a zero is presented with the help of k-congruences. It is shown that a semiring is k-simple iff it is k-congruence-simple, and that inclines are k-simple iff they have at most 2 elements. Lemma 2.12(i) in [Glas. Mat. 42(62) (2007) 301] is pointed out being false

Electronic Transport through QD in the whole temperature range including both the high- and the low-T limits with the equation-of-motion technique

We have studied theoretically the Kondo effect in the quantum dot(QD) within the whole range of temperature by using the equation-of-motion(EOM) technique based on the non-equilibrium Green function formalism. We have taken the finiteness of Coulomb correlation and the non-equilibrium effect into account by calculating the correlation terms emerged from the decoupling approximation using EOM method for the lesser Green function. We showed that the result is in good qualitative agreement with the results of NCA, NRG and NRPT, etc., even using EOM method which is being recognized as a 'conventional' method. The results are the generalization into the pseudo-equilibrium state of the Refs. 32,33 and can be used to describe a non-equilibrium state under the bias voltage which is not so large

Looking for Z' bosons in Supersymmetric E_6 Models through Electroweak Precision Data

We review constraints on additional Z' bosons predicted in supersymmetric (SUSY) E_6 models from electroweak experiments - Z-pole experiments, mW measurements and the low-energy neutral current (LENC) experiments. Four representative models - \chi,\psi, \eta, \nu models - are studied in some detail. We find that the improved data of parity violation in cesium atom, which is 2.2-\sigma away from the Standard Model (SM) prediction, could be explained by the exchange of the heavy mass eigenstate Z_2 in the intermediate state. The improvement over the SM can be found in \chi, \eta, \nu models, where the total \chi^2 of the fit to the 26 data points decreases by about five units, owing to the better fit to the atomic parity violation. Impacts of the kinetic mixing between the U(1)_Y and U(1)' gauge bosons on the \chi^2-analysis are studied. We find that the Z' model with (\beta_E, \delta)=(-\pi/4,0.2), where \beta_E is the mixing angle between Z_\chi and Z_\psi bosons and \delta denotes the kinetic mixing, shows the most excellent fit to the data: the total \chi^2 decreases by about seven units as compared to the SM. We introduce the effective mixing parameter \zeta, a combination of the mass and the kinetic mixing parameters. The 95% CL lower mass bound of Z_2 can be shown as a function of \zeta. A theoretical prediction on \zeta and the U(1)'gauge coupling g_E is studied for the \chi,\psi,\eta and \nu models by assuming the minimal particle content of the SUSY E_6 models.Comment: 20 pages, 3 figures. submitted to the Brief Review section of Mod.Phys.Lett.