Forms and processes of information systems evolution

The way in which software evolves over time has been much studied and is now fairly well-understood. What has been less thoroughly studied are the processes by which information systems – containing software as one component, but also with significant human and organisational aspects – evolve. In many organisations, few information systems are built at all from scratch, but rather are modified from or built on top of existing ones or bolted together from third-party components. In practice, the old division between design, implementation and maintenance has largely disappeared. In this paper, I discuss the nature of IS evolution. I make a distinction between planned (intentional and strategic) evolution, for which we can formulate a clear process; and unplanned (emergent and externally-driven) evolution, where we can simply study the dynamics of the process and be ready for events

Conservation laws and normal forms of evolution equations

We study local conservation laws for evolution equations in two independent variables. In particular, we present normal forms for the equations admitting one or two low-order conservation laws. Examples include Harry Dym equation, Korteweg-de-Vries-type equations, and Schwarzian KdV equation. It is also shown that for linear evolution equations all their conservation laws are (modulo trivial conserved vectors) at most quadratic in the dependent variable and its derivatives.Comment: 16 page

Crypto-unitary forms of quantum evolution operators

For the description of quantum evolution, the use of a manifestly time-dependent quantum Hamiltonian $\mathfrak{h}(t) =\mathfrak{h}^\dagger(t)$ is shown equivalent to the work with its simplified, time-independent alternative $G\neq G^\dagger$. A tradeoff analysis is performed recommending the latter option. The physical unitarity requirement is shown fulfilled in a suitable ad hoc representation of Hilbert space.Comment: 15 p

Nonuniform Dichotomy Spectrum and Normal Forms for Nonautonomous Differential Systems

The aim of this paper is to study the normal forms of nonautonomous differential systems. For doing so, we first investigate the nonuniform dichotomy spectrum of the linear evolution operators that admit a nonuniform exponential dichotomy, where the linear evolution operators are defined by nonautonomous differential equations $\dot x=A(t)x$ in $\R^n$. Using the nonuniform dichotomy spectrum we obtain the normal forms of the nonautonomous linear differential equations. Finally we establish the finite jet normal forms of the nonlinear differential systems $\dot x=A(t)x+f(t,x)$ in $\R^n$, which is based on the nonuniform dichotomy spectrum and the normal forms of the nonautonomous linear systems.Comment: 28 page

Forms of Emergence and the Evolution of Economic Landscapes

Over the past two decades, the notion of ÔemergenceÕ has attracted increasing attention and controversy across the social sciences, as par of a growing interest in the applicability of complexity theory to socio-economic-political systems. Within this context, as economic geographers, our concern in this paper is with the usefulness of the idea of emergence for studying the economic landscape and its evolution. We examine three ÔordersÕ of emergence, and focus attention especially on the third type, Ôdevelopmental or evolutionaryÕ emergence. Despite its limitations, the notion of third order emergence is a potentially valuable organizing concept in economic geography. It provides a framework for exploring how it is that the spatial forms of the economy - clusters, regions, firm networks and so on Ð are recursively related to economic action.Emergence, Supervenience, Downward causation, Evolution, Economic landscape

A plausible mechanism for the evolution of helical forms in nanostructure growth

The observation of helices and coils in nano-tube/-fiber (NT/NF) syntheses is explained on the basis of the interactions between specific catalyst particles and the growing nanostructure. In addition to rationalizing nonlinear structure, the proposed model probes the interplay between thermodynamic quantities and predicts conditions for optimal growth. Experimental results on the effect of indium catalyst on affecting the coil pitch in NTs and NFs are presented

Evolution of Social assistance forms

У статті аналізуються особливості історичного розвитку соціальної допомоги як форми соціальної підтримки. Наводиться класифікація та основні етапи формування теперішнього поняття соціальної допомоги.The Social assistance historical development peculiarities as forms of social support are analyzed in the article. Here is given also the classification and main forming stages of modern term “social support