Supporting software maintenance with non-functional information

The paper highlights the role of non functional information (about efficiency, reliability and other software attributes) of software components in software maintenance, focusing in the component programming framework. Non functional information is encapsulated in modules bound to both definitions and implementations of software components and it is written as expressions in a classical programming language. It is shown with an example how this notation supports software maintenance, with the help of an algorithm which is able to select the best implementation of a software component in its context of use, meaning byPeer ReviewedPostprint (published version

A methodology for obtaining asymptotic estimates for the exponentially small splitting of separatrices to whiskered tori with quadratic frequencies

The aim of this work is to provide asymptotic estimates for the splitting of separatrices in a perturbed 3-degree-of-freedom Hamiltonian system, associated to a 2-dimensional whiskered torus (invariant hyperbolic torus) whose frequency ratio is a quadratic irrational number. We show that the dependence of the asymptotic estimates on the perturbation parameter is described by some functions which satisfy a periodicity property, and whose behavior depends strongly on the arithmetic properties of the frequencies.Comment: 5 pages, 1 figur

Construction of a taxonomy for requirements engineering commercial-off-the-shelf components

This article presents a procedure for constructing a taxonomy of COTS products in the field of Requirements Engineering (RE). The taxonomy and the obtained information reach transcendental benefits to the selection of systems and tools that aid to RE-related actors to simplify and facilitate their work. This taxonomy is performed by means of a goal-oriented methodology inspired in GBRAM (Goal-Based Requirements Analysis Method), called GBTCM (Goal-Based Taxonomy Construction Method), that provides a guide to analyze sources of information and modeling requirements and domains, as well as gathering and organizing the knowledge in any segment of the COTS market. GBTCM claims to promote the use of standards and the reuse of requirements in order to support different processes of selection and integration of components.Peer ReviewedPostprint (published version

An approach to reconcile the agile and CMMI contexts in product line development

Software product line approaches produce reusable platforms and architectures for products set developed by specific companies. These approaches are strategic in nature requiring coordination, discipline, commonality and communication. The Capability Maturity Model (CMM) contains important guidelines for process improvement, and specifies "what" we must have into account to achieve the disciplined processes (among others things). On the other hand, the agile context is playing an increasingly important role in current software engineering practices, specifying "how" the software practices must be addressed to obtain agile processes. In this paper, we carry out a preliminary analysis for reconciling agility and maturity models in software product line domain, taking advantage of both.Postprint (published version

Path-Planning for optimal coverage under security constraints

Treball fet a la Technische Universität Berlin. Fakultät Elektrotechnik und Informatik[ANGLÈS] In recent years, three-dimensional building reconstruction has been an active area of research, partly motivated by the spread of low cost unmanned aerial vehicles platforms. These permit exploiting the entire three-dimensional space as long as it is free of obstacles. Current approaches manually plan a set of viewpoints from which to conduct multiple scans of a target building, and then later select the best ones to use in a structure from motion system. This procedure often has two problems: some parts are covered with low detail or some parts are evenly uncovered. In these situations, an automatic view planner is necessary; it will completely cover a building surface, while reducing time and cost of the overall process. This thesis presents an automatic view planner for three-dimensional building reconstruction based on dividing edifices into several slices and for each one solve a two-dimensional problem. From a rough model of the environment and a desired detail level, both described in a cost function, the system computes a route in which there is a set of viewpoints to completely cover a target building surface of any shape, taking into account that there may be obstacles in the environment. The final route is proposed to be followed by an unmanned aerial vehicle equipped with a digital camera.[CASTELLÀ] En los últimos años, la reconstrucción 3D de edificios ha sido un área activa de investigación, en parte motivada por la difusión de plataformas económicas de unmanned aerial vehicles. Estos permiten explotar completamente el espacio 3D mientras esté libre de obstáculos. Las soluciones actuales planean manualmente una serie de puntos desde donde realizar escaneos de un edificio objetivo, para luego seleccionar los mejores para utilizar en un sistema structure from motion. Este procedimiento a menudo tiene dos grandes problemas: algunas partes del edificio se cubren con bajo detalle u otras partes incluso no se cubren. En estas situaciones un view planner automático es necesario. Este cubrirá completamente la superficie del edificio, a la vez que reducirá costes y tiempo en el proceso global. Este proyecto presenta un view planner automático para la reconstrucción 3D de edificios basado en dividir estos en rebanadas y para cada una resolver un problema en 2D. A partir de un modelo en bruto de la escena, y un detalle deseado, ambos descritos en una función de coste, el sistema calcula una ruta en la que hay una serie de puntos que cubren completamente la superficie de un edificio objetivo de cualquier forma, teniendo en cuenta que puede haber obstáculos en la escena. La idea es que un unmanned aerial vehicle equipado con una cámara digital siga el camino final diseñado.[CATALÀ] Els darrers anys, la reconstrucció 3D d’edificis ha estat una área activa de recerca, en part motivada per la difusió de plataformes econòmiques de unmanned aerial vehicles. Aquests permeten explotar completament l’espai 3D mentres estigui lliure d’obstacles. Les solucions actuals planegen manualment una sèrie de punts des don realitzar escanejos d’un edifici objectiu, per després seleccionar els millors per a utilitzar en un sistema structure from motion. Aquest procediment sovint té dos grans problemes: algunes parts de l’edifici es cobreixen amb baix detall o altres parts inclús no es cobreixen. En aquestes situacions un view planner automàtic es necessari. Aquest cobrirà completament la superfície de l’edifici, a la vegada que reduirà costos i temps en el procés global. Aquest projecte presenta un view planner automàtic per a la reconstrucció 3D d’edificis basat en dividir aquests en llesques i per a cada una resoldre un problema en 2D. A partir d’un model en brut de l’escena, i un detall desitjat, ambdós descrits en una funció de cost, el sistema calcula una ruta en la qual hi ha una serie de punts que cobriran completament la superfície d’un edifici objectiu de qualsevol forma, tenint en compte que hi poden haver obstacles a l’escena. La idea es que un unmanned aerial vehicle equipat amb una càmera digital segueixi el camí final dissenyat

Putting non-functional requirements into software architecture

This paper presents an approach for incorporating non-functional information of software system into software architectures. To do so, components present two distinguished slots: their non-functional specification, where non-functional requirements on components are placed, and their non-functional behaviour with respect to these requirements. Also, connector protocols may describe which non-functional aspects are relevant to component connections. We propose a notation to describe non-functionality in a systematic manner, and we use it to analyse two particular aspects of the meeting scheduler case study, user interaction and performance.Peer ReviewedPostprint (published version

Estimates on invariant tori near an elliptic equilibrium point of a Hamiltonian system

We give a precise statement for KAM theorem in a neighbourhood of an elliptic equilibrium point of a Hamiltonian system. If the frequencies of the elliptic point are nonresonant up to a certain order $K\ge4$, and a nondegeneracy condition is fulfilled, we get an estimate for the measure of the complement of the KAM tori in a neighbourhood of given radius. Moreover, if the frequencies satisfy a Diophantine condition, with exponent $\tau$, we show that in a neighbourhood of radius $r$ the measure of the complement is exponentially small in $(1/r)^{1/(\tau+1)}$. We also give a related result for quasi-Diophantine frequencies, which is more useful for practical purposes. The results are obtained by putting the system in Birkhoff normal form up to an appropiate order, and the key point relies on giving accurate bounds for its terms

Exponentially small splitting of separatrices for whiskered tori in Hamiltonian systems

We study the existence of transverse homoclinic orbits in a singular or weakly hyperbolic Hamiltonian, with $3$ degrees of freedom, as a model for the behaviour of a nearly-integrable Hamiltonian near a simple resonance. The example considered consists of an integrable Hamiltonian possessing a $2$-dimensional hyperbolic invariant torus with fast frequencies $\omega/\sqrt\varepsilon$ and coincident whiskers or separatrices, plus a perturbation of order $\mu=\varepsilon^p$, giving rise to an exponentially small splitting of separatrices. We show that asymptotic estimates for the transversality of the intersections can be obtained if $\omega$ satisfies certain arithmetic properties. More precisely, we assume that $\omega$ is a quadratic vector (i.e.~the frequency ratio is a quadratic irrational number), and generalize the good arithmetic properties of the golden vector. We provide a sufficient condition on the quadratic vector $\omega$ ensuring that the Poincar\'e--Melnikov method (used for the golden vector in a previous work) can be applied to establish the existence of transverse homoclinic orbits and, in a more restrictive case, their continuation for all values of $\varepsilon\to0$

Homoclinic orbits to invariant tori in Hamiltonian systems

We consider a perturbation of an integrable Hamiltonian system which possesses invariant tori with coincident whiskers (like some rotators and a pendulum). Our goal is to measure the splitting distance between the perturbed whiskers, putting emphasis on the detection of their intersections, which give rise to homoclinic orbits to the perturbed tori. A geometric method is presented which takes into account the Lagrangian properties of the whiskers. In this way, the splitting distance is the gradient of a splitting potential. In the regular case (also known as a priori-unstable: the Lyapunov exponents of the whiskered tori remain fixed), the splitting potential is well- approximated by a Melnikov potential. This method is designed as a first step in the study of the singular case (also known as a priori-stable: the Lyapunov exponents of the whiskered tori approach to zero when the perturbation tends to zero)

Splitting and melnikov potentials in hamiltonian systems

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