Software engineering challenges: Achieving zero carbon buildings by 2019

The planet Earth is warming up. There is an urgent need to reduce greenhouse gas emissions. Buildings account for almost 50% of UK carbon dioxide emissions. [1] The UK Government have set out a programme to make all new buildings zero carbon by 2019. This will require a paradigm shift in how buildings are designed, with an increased reliance on computational modelling of building performance early in the design process. This paper outlines how architects have traditionally worked, the available software and how it is used. It discusses the challenges faced by building designers in achieving zero carbon buildings and then outlines how software tools might develop to meet not only the zero carbon challenge but also take the concept further to help design sustainable buildings

Using Problem Frames and projections to analyze requirements for distributed systems

Subproblems in a problem frames decomposition frequently make use of projections of the complete problem context. One specific use of projec-tions occurs when an eventual implementation will be distributed, in which case a subproblem must interact with (use) the machine in a projection that represents another subproblem. We refer to subproblems used in this way as services, and propose an extension to projections to represent services as a spe-cial connection domain between subproblems. The extension provides signifi-cant benefits: verification of the symmetry of the interfaces, exposure of the machine-to-machine interactions, and prevention of accidental introduction of shared state. The extension’s usefulness is validated using a case study

Using Dynamic Aspects in Music Composition Systems

Aspect-oriented programming (AOP) attempts to modularise crosscutting concerns in software. Initial approaches to AOP have used static weaving techniques in which crosscutting implementation, encapsulated by aspects, is merged into . Research into dynamic aspects suggests various ways in which crosscutting implementations may be dynamically woven into code, enabling aspects to be defined and composed at run-time. It has been suggested, in [14], that AOP might be usefully applied at the end-user level in applications that support multidimensional creative processes, and in particular, of music composition. In this paper we extend this argument to suggest that dynamic aspects are essential to this application. We motivate our argument with a high-level description of crosscutting that exists within music composition, and ways in which these crosscutting concerns, and requirements for their management, have arisen from our initial use of static aspects in music composition. We then evaluate some of the ways in which current research into dynamic aspects might be utilised in addressing these requirements

Applying aspect-oriented programming to music computing

Computer programs for the composition, performance and analysis of music generally involve the tangled interaction of many dimensions of musical and extra-musical concern. In this paper we introduce the concepts of Aspect-Oriented Programming (AOP) to Music Computing and argue that AOP and related techniques and technologies form an appropriate solution to the separation and composition of such concerns. We motivate our argument with simple examples from the musical domain, but argue that the underlying principles may be applied to a wide and expressive range of musical application

Deriving security requirements from crosscutting threat descriptions

It is generally accepted that early determination of the stakeholder requirements assists in the development of systems that better meet the needs of those stakeholders. General security requirements frustrate this goal because it is difficult to determine how they affect the functional requirements of the system. This paper illustrates how representing threats as crosscutting concerns aids in determining the effect of security requirements on the functional requirements. Assets (objects that have value in a system) are first enumerated, and then threats on these assets are listed. The points where assets and functional requirements join are examined to expose vulnerabilities to the threats. Security requirements, represented as constraints, are added to the functional requirements to reduce the scope of the vulnerabilities. These requirements are used during the analysis and specification process, thereby incorporating security concerns into the functional requirements of the system

An introduction to aspect-oriented music representation

This paper introduces Aspect Oriented Music Representation (AOMR), and its application to create tools offering new kinds of flexibility to musicians. Psychologists have demonstrated the diversity of composers' approaches, but existing computer-based tools support this diversity poorly. Current tools generally require musicians to work with pre-established abstractions and operations. AOMR systematically allows composers to create and work with musical viewpoints of their choice. This paper uses simple case studies to analyse a prototype AOMR implementation and characterise the new kinds of flexibility it affords to musicians

Modelling the similarity of pitch collections with expectation tensors

Models of the perceived distance between pairs of pitch collections are a core component of broader models of music cognition. Numerous distance measures have been proposed, including voice-leading [1], psychoacoustic [2–4], and pitch and interval class distances [5]; but, so far, there has been no attempt to bind these different measures into a single mathematical or conceptual framework, nor to incorporate the uncertain or probabilistic nature of pitch perception. This paper embeds pitch collections in expectation tensors and shows how metrics between such tensors can model their perceived dissimilarity. Expectation tensors indicate the expected number of tones, ordered pairs of tones, ordered triples of tones, etc., that are heard as having any given pitch, dyad of pitches, triad of pitches, etc.. The pitches can be either absolute or relative (in which case the tensors are invariant with respect to transposition). Examples are given to show how the metrics accord with musical intuition

Gaia Data Release 1: Testing parallaxes with local Cepheids and RR Lyrae stars

Context. Parallaxes for 331 classical Cepheids, 31 Type II Cepheids, and 364 RR Lyrae stars in common between Gaia and the Hipparcos and Tycho-2 catalogues are published in Gaia Data Release 1 (DR1) as part of the Tycho-Gaia Astrometric Solution (TGAS). Aims. In order to test these first parallax measurements of the primary standard candles of the cosmological distance ladder, which involve astrometry collected by Gaia during the initial 14 months of science operation, we compared them with literature estimates and derived new period-luminosity (PL), period-Wesenheit (PW) relations for classical and Type II Cepheids and infrared PL, PL-metallicity (PLZ), and optical luminosity-metallicity (M V -[Fe/H]) relations for the RR Lyrae stars, with zero points based on TGAS. Methods. Classical Cepheids were carefully selected in order to discard known or suspected binary systems. The final sample comprises 102 fundamental mode pulsators with periods ranging from 1.68 to 51.66 days (of which 33 with σ Ω /Ω < 0.5). The Type II Cepheids include a total of 26 W Virginis and BL Herculis stars spanning the period range from 1.16 to 30.00 days (of which only 7 with σ Ω /Ω < 0.5). The RR Lyrae stars include 200 sources with pulsation period ranging from 0.27 to 0.80 days (of which 112 with σ Ω /Ω < 0.5). The new relations were computed using multi-band (V,I,J,K s ) photometry and spectroscopic metal abundances available in the literature, and by applying three alternative approaches: (i) linear least-squares fitting of the absolute magnitudes inferred from direct transformation of the TGAS parallaxes; (ii) adopting astrometry-based luminosities; and (iii) using a Bayesian fitting approach. The last two methods work in parallax space where parallaxes are used directly, thus maintaining symmetrical errors and allowing negative parallaxes to be used. The TGAS-based PL,PW,PLZ, and M V - [Fe/H] relations are discussed by comparing the distance to the Large Magellanic Cloud provided by different types of pulsating stars and alternative fitting methods. Results. Good agreement is found from direct comparison of the parallaxes of RR Lyrae stars for which both TGAS and HST measurements are available. Similarly, very good agreement is found between the TGAS values and the parallaxes inferred from the absolute magnitudes of Cepheids and RR Lyrae stars analysed with the Baade-Wesselink method. TGAS values also compare favourably with the parallaxes inferred by theoretical model fitting of the multi-band light curves for two of the three classical Cepheids and one RR Lyrae star, which were analysed with this technique in our samples. The K-band PL relations show the significant improvement of the TGAS parallaxes for Cepheids and RR Lyrae stars with respect to the Hipparcos measurements. This is particularly true for the RR Lyrae stars for which improvement in quality and statistics is impressive. Conclusions. TGAS parallaxes bring a significant added value to the previous Hipparcos estimates. The relations presented in this paper represent the first Gaia-calibrated relations and form a work-in-progress milestone report in the wait for Gaia-only parallaxes of which a first solution will become available with Gaia Data Release 2 (DR2) in 2018. © ESO, 2017

Evolution of aspects for legacy system security concerns

This paper shows how aspects can be successfully employed in the support of system evolution. The context is a case study on migrating a legacy client-server application to overcome the security problems associated with 'message tampering' attacks. The focus is on authorization issues in which aspects are used to add a security mechanism based on digital signatures. The approach provides for future evolution of the system. In particular, it is shown how factoring of aspectual concerns allows the scope of the security boundary to be varied, illustrating reuse of the aspects. Whilst the aspects are added non-intrusively, it is demonstrated how aspects can modify the control-flow behaviour of a server. We propose a programming idiom that conforms to Design by Contract