70,779 research outputs found
An R library for compositional data analysis in archaeometry
Compositional data naturally arises from the scientific analysis of the chemical
composition of archaeological material such as ceramic and glass artefacts. Data of this
type can be explored using a variety of techniques, from standard multivariate methods
such as principal components analysis and cluster analysis, to methods based upon the
use of log-ratios. The general aim is to identify groups of chemically similar artefacts
that could potentially be used to answer questions of provenance.
This paper will demonstrate work in progress on the development of a documented
library of methods, implemented using the statistical package R, for the analysis of
compositional data. R is an open source package that makes available very powerful
statistical facilities at no cost. We aim to show how, with the aid of statistical software
such as R, traditional exploratory multivariate analysis can easily be used alongside, or
in combination with, specialist techniques of compositional data analysis.
The library has been developed from a core of basic R functionality, together with
purpose-written routines arising from our own research (for example that reported at
CoDaWork'03). In addition, we have included other appropriate publicly available
techniques and libraries that have been implemented in R by other authors. Available
functions range from standard multivariate techniques through to various approaches to
log-ratio analysis and zero replacement. We also discuss and demonstrate a small
selection of relatively new techniques that have hitherto been little-used in
archaeometric applications involving compositional data. The application of the library
to the analysis of data arising in archaeometry will be demonstrated; results from
different analyses will be compared; and the utility of the various methods discussedGeologische Vereinigung; Institut dāEstadĆstica de Catalunya; International Association for Mathematical Geology; Patronat de lāEscola PolitĆØcnica Superior de la Universitat de Girona; FundaciĆ³ privada: Girona, Universitat i Futur; CĆ tedra LluĆs SantalĆ³ dāAplicacions de la MatemĆ tica; Consell Social de la Universitat de Girona; Ministerio de Ciencia i TecnologĆa
Graphical modelling language for spycifying concurrency based on CSP
Introduced in this (shortened) paper is a graphical modelling language for specifying concurrency in software designs. The language notations are derived from CSP and the resulting designs form CSP diagrams. The notations reflect both data-flow and control-flow aspects of concurrent software architectures. These designs can automatically be described by CSP algebraic expressions that can be used for formal analysis. The designer does not have to be aware of the underlying mathematics. The techniques and rules presented provide guidance to the development of concurrent software architectures. One can detect and reason about compositional conflicts (errors in design), potential deadlocks (errors at run-time), and priority inversion problems (performance burden) at a high level of abstraction. The CSP diagram collaborates with objectoriented modelling languages and structured methods
Integrating the common variability language with multilanguage annotations for web engineering
Web applications development involves managing a high diversity of files and resources like code, pages or style sheets, implemented in different languages. To deal with the automatic generation of
custom-made configurations of web applications, industry usually adopts annotation-based approaches even though the majority of studies encourage the use of composition-based approaches to implement
Software Product Lines. Recent work tries to combine both approaches to get the complementary benefits. However, technological companies are reticent to adopt new development paradigms
such as feature-oriented programming or aspect-oriented programming.
Moreover, it is extremely difficult, or even impossible, to apply
these programming models to web applications, mainly because of
their multilingual nature, since their development involves multiple
types of source code (Java, Groovy, JavaScript), templates (HTML,
Markdown, XML), style sheet files (CSS and its variants, such as
SCSS), and other files (JSON, YML, shell scripts). We propose to
use the Common Variability Language as a composition-based approach
and integrate annotations to manage fine grained variability
of a Software Product Line for web applications. In this paper, we (i)
show that existing composition and annotation-based approaches,
including some well-known combinations, are not appropriate to
model and implement the variability of web applications; and (ii)
present a combined approach that effectively integrates annotations
into a composition-based approach for web applications. We implement
our approach and show its applicability with an industrial
real-world system.Universidad de MĆ”laga. Campus de Excelencia Internacional AndalucĆa Tech
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Developing Integrated Waste Management Systems: Information Needs and the Role of Locally Based Data
No abstract available
Proceedings of International Workshop "Global Computing: Programming Environments, Languages, Security and Analysis of Systems"
According to the IST/ FET proactive initiative on GLOBAL COMPUTING, the goal is to obtain techniques (models, frameworks, methods, algorithms) for constructing systems that are flexible, dependable, secure, robust and efficient.
The dominant concerns are not those of representing and manipulating data efficiently but rather those of handling the co-ordination and interaction, security, reliability, robustness, failure modes, and control of risk of the entities in the system and the overall design, description and performance of the system itself.
Completely different paradigms of computer science may have to be developed to tackle these issues effectively. The research should concentrate on systems having the following characteristics: ā¢ The systems are composed of autonomous computational entities where activity is not centrally controlled, either because global control is impossible or impractical, or because the entities are created or controlled by different owners.
ā¢ The computational entities are mobile, due to the movement of the physical platforms or by movement of the entity from one platform to another.
ā¢ The configuration varies over time. For instance, the system is open to the introduction of new computational entities and likewise their deletion.
The behaviour of the entities may vary over time.
ā¢ The systems operate with incomplete information about the environment.
For instance, information becomes rapidly out of date and mobility requires information about the environment to be discovered.
The ultimate goal of the research action is to provide a solid scientific foundation for the design of such systems, and to lay the groundwork for achieving effective principles for building and analysing such systems.
This workshop covers the aspects related to languages and programming environments as well as analysis of systems and resources involving 9 projects (AGILE , DART, DEGAS , MIKADO, MRG, MYTHS, PEPITO, PROFUNDIS, SECURE) out of the 13 founded under the initiative. After an year from the start of the projects, the goal of the workshop is to fix the state of the art on the topics covered by the two clusters related to programming environments and analysis of systems as well as to devise strategies and new ideas to profitably continue the research effort towards the overall objective of the initiative.
We acknowledge the Dipartimento di Informatica and Tlc of the University of Trento, the Comune di Rovereto, the project DEGAS for partially funding the event and the Events and Meetings Office of the University of Trento for the valuable collaboration
The composition of Event-B models
The transition from classical B [2] to the Event-B language and method [3] has seen the removal of some forms of model structuring and composition, with the intention of reinventing them in future. This work contributes to thatreinvention. Inspired by a proposed method for state-based decomposition and refinement [5] of an Event-B model, we propose a familiar parallel event composition (over disjoint state variable lists), and the less familiar event fusion (over intersecting state variable lists). A brief motivation is provided for these and other forms of composition of models, in terms of feature-based modelling. We show that model consistency is preserved under such compositions. More significantly we show that model composition preserves refinement
SameSameButDifferent v.02 ā Iceland
The history of computer music is to a great extent the history of algorithmic composition. Here generative approaches are seen as an artistic technique. However, the generation of algorithmic music is normally done in the studio, where the music is aesthetically valued by the composer. The public only gets to know one, or perhaps few, variations of the expressive scope of the algorithmic system itself. In this paper, we describe a generative music system of infinite compositions, where the system itself is aimed for distribution and to be used on personal computers. This system has a dual structure of a compositional score and a performer that performs the score in real-time every time a piece is played. We trace the contextual background of such systems and potential future applications
Algorithms as scores: coding live music
The author discusses live coding as a new path in the evolution of the musical score. Live-coding practice accentu- ates the score, and whilst it is the perfect vehicle for the performance of algorithmic music it also transforms the compositional process itself into a live event. As a continuation of 20th-century artistic developments of the musical score, live-coding systems often embrace graphical elements and language syntaxes foreign to standard programming languages. The author presents live coding as a highly technologized artistic practice, shedding light on how non-linearity, play and generativity will become prominent in future creative media productions
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