Theoretical analysis of resonance states in 4H^{4}H, 4He^{4}He and 4Li^{4}Li above three-cluster threshold

The resonance states of $^{4}H$, $^{4}He$ and $^{4}Li$, embedded in the three-cluster $d+N+N$ continuum, are investigated within a three-cluster model. The model treats the Pauli principle exactly and incorporates the Faddeev components for proper description of the boundary conditions for the two- and three-body continua. The hyperspherical harmonics are used to distinguish and numerate channels of the three-cluster continuum. It is shown that the effective barrier, created by three-cluster configuration $d+N+N$, is strong enough to accommodate two resonance states.Comment: 20 page, 4 figure

Publishing H2O pluglets in UDDI registries

Interoperability and standards, such as Grid Services are a focus of current Grid research. The intent is to facilitate resource virtualization, and to accommodate the intrinsic heterogeneity of resources in distributed environments. It is important that new and emerging metacomputing frameworks conform to these standards, in order to ensure interoperability with other grid solutions. In particular, the H2O metacomputing system offers several benefits, including lightweight operation, user-configurability, and selectable security levels. Its applicability would be enhanced even further through support for grid services and OGSA compliance. Code deployed into the H2O execution containers is referred to as pluglets. These pluglets constitute the end points of services in H2O, services that are to be made known through publication in a registry. In this contribution, we discuss a system pluglet, referred to as OGSAPluglet, that scans H2O execution containers for available services and publishes them into one or more UDDI registries. We also discuss in detail the algorithms that manage the publication of the appropriate WSDL and GSDL documents for the registration process

Resource Pricing In A Dynamic Multi-Commodity Market For Computational Resources

The adoption of market-based principles in resource management systems for computational infrastructures such as grids and clusters allows for matching demand and supply for resources in a utility maximizing manner. As such, they offer a promise of producing more efficient resource allocations, compared to traditional system-centric approaches that do not allow consumers and providers to express their valuations for computational resources. In this paper, we investigate the pricing of resources in grids through the use of a computational commodity market of CPU resources, where resource prices are determined through the computation of a supply-and-demand equilibrium. In particular, we introduce several categories of CPUs characterized by their execution speed. These differ in cost and performance but may be used interchangeably in executing jobs and thus represent so-called substitutable resources. We investigate the performance of the algorithms for computing the supply-and-demand equilibrium in this multi-commodity setting under dynamically varying consumer and provider populations.Comment: 14 Pages, IJCNC Journa

Magnetic pulse welding

The contemporary construction industry is evolving with a rapid pace and is pushing technological boundaries. Together with that progress new requirements on joints and joining techniques are imposed. This paper describes our research concerning an advanced joining technique, the Magnetic Pulse Welding process (MPW). The first part of this article briefly describes the MPW process and summarizes the differences with respect to conservative welding techniques. Secondly an analytical model of the process will be investigated on accuracy. This model was developed by the manufacturer of the MPW machine used at the Belgian Welding Institute. Further a description is given of the methods which are used to investigate the experimental joints. After describing the recently performed experiments, finally an overview will be given depicting the work that will be carried out during the rest of this master thesi

Algebraic Model for scattering of three-s-cluster systems; 2, Resonances in the three-cluster continuum of 6He and 6Be

The resonance states embedded in the three-cluster continuum of 6He and 6Be are obtained in the Algebraic Version of the Resonating Group Method. The model accounts for a correct treatment of the Pauli principle. It also provides the correct three-cluster continuum boundary conditions by using a Hyperspherical Harmonics basis. The model reproduces the observed resonances well and achieves good agreement with other models. A better understanding for the process of formation and decay of the resonance states in six-nucleon systems is obtained

Taming the Yukawa potential singularity: improved evaluation of bound states and resonance energies

Using the tools of the J-matrix method, we absorb the 1/r singularity of the Yukawa potential in the reference Hamiltonian, which is handled analytically. The remaining part, which is bound and regular everywhere, is treated by an efficient numerical scheme in a suitable basis using Gauss quadrature approximation. Analysis of resonance energies and bound states spectrum is performed using the complex scaling method, where we show their trajectories in the complex energy plane and demonstrate the remarkable fact that bound states cross over into resonance states by varying the potential parameters.Comment: 8 pages, 2 tables, 1 figure. 2 mpg videos and 1 pdf table file are available upon request from the corresponding Autho

Numerical bifurcation analysis of pattern formation in a cell based auxin transport model

Transport models of growth hormones can be used to reproduce the hormone accumulations that occur in plant organs. Mostly, these accumulation patterns are calculated using time step methods, even though only the resulting steady state patterns of the model are of interest. We examine the steady state solutions of the hormone transport model of Smith et al (2006) for a one-dimensional row of plant cells. We search for the steady state solutions as a function of three of the model parameters by using numerical continuation methods and bifurcation analysis. These methods are more adequate for solving steady state problems than time step methods. We discuss a trivial solution where the concentrations of hormones are equal in all cells and examine its stability region. We identify two generic bifurcation scenarios through which the trivial solution loses its stability. The trivial solution becomes either a steady state pattern with regular spaced peaks or a pattern where the concentration is periodic in time.Comment: submitte