A model based approach to systems requirements for event driven enterprise architecture

Business and ICT strategic alignment remains an ongoing challenge facing organizations as they react to changing requirements by adapting or introducing new technologies to existing infrastructure. Activity around Enterprise Architecture (EA) has increasingly become relevant to these demands and as a consequence numerous methods and frameworks for pursuing EA have emerged. However these approaches remain bloated, time-consuming and lacking in precision. This paper proposes a light-weight method for enterprise architecture and introduces a language for representing EA components that lends itself to modeling “As Is” and “To Be” EA with a concrete aim to providing a simulation environment that delivers an un-ambiguous description to what changes need to be made to an EA with respect to emerging requirements. The LEAP method and the language is illustrated with a detailed case study of business change currently being addressed by UK higher education institutions

A method for enterprise architecture alignment

Business and ICT strategic alignment remains an ongoing challenge facing organizations as they react to changing requirements by adapting or introducing new technologies to existing infrastructure. Enterprise Architecture (EA) has increasingly become relevant to these demands and as a consequence numerous methods and frameworks have emerged. However these approaches remain bloated, time-consuming and lacking in precision. This paper proposes a light-weight method for EA called LEAP and introduces a language for EA simulation that is illustrated with a detailed case study of business change currently being addressed by UK higher education institutions

LEAP: a precise lightweight framework for enterprise architecture.

This paper proposes LEAP: a simple framework for Enterprise Architecture (EA) that views an organization as an engine that executes in terms of hierarchically decomposed communicating components. The approach allows all aspects of the architecture to be precisely dened using standard modelling notations. Given that the approach is simple and precisely dened it can form the basis for a wide range of EA analysis techniques including simulation, compliance and consistency checking. The paper denes the LEAP framework and shows that it can be used to represent the key features of ArchiMate whilst containing fewer orthogonal concepts. We also show that the precision of LEAP, achieved through the use of OCL, can be used to verify both the claims made for inter-layer relationships in EA models and for extensions to ArchiMate

Simulating enterprise architecture models

Business and ICT strategic alignment remains an ongoing challenge facing organizations as they react to changing requirements by adapting or introducing new technologies to existing infrastructure. Enterprise Architecture (EA) has increasingly become relevant to these demands and as a consequence numerous methods and frameworks for pursuing EA have emerged. However these approaches remain bloated, time-consuming and lacking in precision. This paper proposes a lightweight method for EA (LEAP) and introduces a language for representing EA components that lends itself to modelling as-is and to-be EA with a concrete aim to providing a simulation environment that delivers an unambiguous description of the required changes. The LEAP method and the language are illustrated with a detailed case study of business change currently being addressed by UK higher education institutions

An e-learning support toolkit for social work students on placement

Students of the social work professions generally are required to be placed in social work settings and to undergo assessment in the workplace during their training. These students are usually supported by qualified practice tutors who regularly meet with them and give feedback on their practice performance and progress. The support procedure sometimes is fragile and affects the quality of the students? learning experience. Through a user centered design approach, the Remora project aims to provide an integration of mobile software toolkits and social software applications to support work-based learning and assessment for social workers. Two main applications are created and deployed on two categories of portable devices to help practice workers in their administration, information sharing and collection of documents linking with competency learning resources. The applications are extendible to be applicable to any work-based learning situation

Transverse and secondary voltages in BSCCO single crystals

Multicontact configuration is one of the most powerful arrangements for electrical transport measurements applied to study vortex phase transition and vortex phase dimensionality in strongly anisotropic high-Tc superconducting materials. In this paper we present electrical transport measurements using a multiterminal configuration, which prove both the existence of guided vortex motion in BSCCO single crystals near the transition temperature and that secondary voltage in zero external magnetic field is induced by thermally activated vortex loop unbinding. The phase transition between the bound and unbound states of the vortex loops was found to be below the temperature where the phase coherence of the superconducting order parameter extends over the whole volume of the sample. We show experimentally that 3D/2D phase transition in vortex dimensionality is a length-scale-dependent layer decoupling process and takes place simultaneously with the 3D/2D phase transition in superconductivity at the same temperature.Comment: 8 pages, 5 figures, to be published in Physica

Dynamics of the magnetic flux trapped in fractal clusters of normal phase in a superconductor

The influence of geometry and morphology of superconducting structure on critical currents and magnetic flux trapping in percolative type-II superconductor is considered. The superconductor contains the clusters of a normal phase, which act as pinning centers. It is found that such clusters have significant fractal properties. The main features of these clusters are studied in detail: the cluster statistics is analyzed; the fractal dimension of their boundary is estimated; the distribution of critical currents is obtained, and its peculiarities are explored. It is examined thoroughly how the finite resolution capacity of the cluster geometrical size measurement affects the estimated value of fractal dimension. The effect of fractal properties of the normal phase clusters on the electric field arising from magnetic flux motion is investigated in the case of an exponential distribution of cluster areas. The voltage-current characteristics of superconductors in the resistive state for an arbitrary fractal dimension are obtained. It is revealed that the fractality of the boundaries of the normal phase clusters intensifies the magnetic flux trapping and thereby raises the critical current of a superconductor.Comment: revtex, 16 pages with 1 table and 5 figures; text and figures are improved; more detailed version with geometric probability analisys of the distribution of entry points into weak links over the perimeter of a normal phase clusters and one additional figure is published in Phys.Rev.B; alternative e-mail of author is [email protected]

Vortex Plastic Motion in Twinned Superconductors

We present simulations, without electrodynamical assumptions, of $B(x,y,H(t)), M(H(t))$, and $J_c(H(t))$, in hard superconductors, for a variety of twin-boundary pinning potential parameters, and for a range of values of the density and strength of the pinning sites. We numerically solve the overdamped equations of motion of up to 10^4 flux-gradient-driven vortices which can be temporarily trapped at $\sim 10^6$ pinning centers. These simulations relate macroscopic measurements (e.g., M(H), ``flame'' shaped $B(x,y)$ profiles) with the underlying microscopic pinning landscape and the plastic dynamics of individual vortices

Evidence for vortex staircases in the whole angular range due to competing correlated pinning mechanisms

We analyze the angular dependence of the irreversible magnetization of YBa$_2$Cu$_3$O$_7$ crystals with columnar defects inclined from the c-axis. At high fields a sharp maximum centered at the tracks' direction is observed. At low fields we identify a lock-in phase characterized by an angle-independent pinning strength and observe an angular shift of the peak towards the c-axis that originates in the material anisotropy. The interplay among columnar defects, twins and ab-planes generates a variety of staircase structures. We show that correlated pinning dominates for all field orientations.Comment: 9 figures, 4 figure

Spatio-temporal dynamics and plastic flow of vortices in superconductors with periodic arrays of pinning sites

We present simulations of flux-gradient-driven superconducting rigid vortices interacting with square and triangular arrays of columnar pinning sites in an increasing external magnetic field. These simulations allow us to quantitatively relate spatio-temporal microscopic information of the vortex lattice with typically measured macroscopic quantities, such as the magnetization $M(H)$. The flux lattice does not become completely commensurate with the pinning sites throughout the sample at the magnetization matching peaks, but forms a commensurate lattice in a region close to the edge of the sample. Matching fields related to unstable vortex configurations do not produce peaks in $M(H)$. We observe a variety of evolving complex flux profiles, including flat terraces or plateaus separated by winding current-carrying strings and, near the peaks in $M(H)$, plateaus only in certain regions, which move through the sample as the field increases