27,308 research outputs found
A Graph Rewriting Approach for Transformational Design of Digital Systems
Transformational design integrates design and verification. It combines “correctness by construction” and design creativity by the use of pre-proven behaviour preserving transformations as design steps. The formal aspects of this methodology are hidden in the transformations. A constraint is the availability of a design representation with a compositional formal semantics. Graph representations are useful design representations because of their visualisation of design information. In this paper graph rewriting theory, as developed in the last twenty years in mathematics, is shown to be a useful basis for a formal framework for transformational design. The semantic aspects of graphs which are no part of graph rewriting theory are included by the use of attributed graphs. The used attribute algebra, table algebra, is a relation algebra derived from database theory. The combination of graph rewriting, table algebra and transformational design is new
Information technology as boundary object for transformational learning
Collaborative work is considered as a way to improve productivity and value generation in
construction. However, recent research demonstrates that socio-cognitive factors related to fragmentation of specialized knowledge may hinder team performance. New methods based on theories of practice are emerging in Computer Supported Collaborative Work and organisational learning to break these knowledge boundaries,
facilitating knowledge sharing and the generation of new knowledge through transformational learning. According to these theories, objects used in professional practice play a key role in mediating interactions. Rules and methods related to these practices are also embedded in these objects. Therefore changing collaborative
patterns demand reconfiguring objects that are at the boundary between specialized practices, namely boundary objects. This research is unique in presenting an IT strategy in which technology is used as a boundary object to facilitate transformational learning in collaborative design work
Object-based Control/Data-flow Analysis
Not only does a clear distinction between control and data flow enhance the readability of models, but it also allows different tools to operate on the two distinct parts of the model. This paper shows how the modelling based on control/data-flow analysis can benefit from an object-based approach. We have developed a translation mechanism that is faithful and gives an extra dimension (hierarchy) to the existing paradigm of control and data flow interacting in a model. Our methodology provides a comprehensible separation of these two parts, which can be used to feed another analysis or synthesis tools, while still being able to reason about both parts through formal methods of verification
PROSET — A Language for Prototyping with Sets
We discuss the prototyping language PROSET(Prototyping with Sets) as a language for experimental and evolutionary prototyping, focusing its attention on algorithm design. Some of PROSET’s features include generative communication, flexible exception handling and the integration of persistence. A discussion of some issues pertaining to the compiler and the programming environment conclude the pape
Capturing natural-colour 3D models of insects for species discovery
Collections of biological specimens are fundamental to scientific
understanding and characterization of natural diversity. This paper presents a
system for liberating useful information from physical collections by bringing
specimens into the digital domain so they can be more readily shared, analyzed,
annotated and compared. It focuses on insects and is strongly motivated by the
desire to accelerate and augment current practices in insect taxonomy which
predominantly use text, 2D diagrams and images to describe and characterize
species. While these traditional kinds of descriptions are informative and
useful, they cannot cover insect specimens "from all angles" and precious
specimens are still exchanged between researchers and collections for this
reason. Furthermore, insects can be complex in structure and pose many
challenges to computer vision systems. We present a new prototype for a
practical, cost-effective system of off-the-shelf components to acquire
natural-colour 3D models of insects from around 3mm to 30mm in length. Colour
images are captured from different angles and focal depths using a digital
single lens reflex (DSLR) camera rig and two-axis turntable. These 2D images
are processed into 3D reconstructions using software based on a visual hull
algorithm. The resulting models are compact (around 10 megabytes), afford
excellent optical resolution, and can be readily embedded into documents and
web pages, as well as viewed on mobile devices. The system is portable, safe,
relatively affordable, and complements the sort of volumetric data that can be
acquired by computed tomography. This system provides a new way to augment the
description and documentation of insect species holotypes, reducing the need to
handle or ship specimens. It opens up new opportunities to collect data for
research, education, art, entertainment, biodiversity assessment and
biosecurity control.Comment: 24 pages, 17 figures, PLOS ONE journa
Separating Control and Data Flow: Methodology and Automotive System Case Study
In this document we propose to study the control/data flow separation design methodology, using Scade and Mode-Automata, and its application in the design of an automotive system. This methodology allows to facilitate the specification of different kinds of systems and to have a better readability. It also separates the study of the different parts by using the most appropriate existing tools for each of them. To do that, we study a cruise control system with GPS which makes possible the control of a car speed depending on its position given by a GPS. This system combines both control and data processing and can be specified using our methodology. The goal of this work consists in presenting the application of our methodology on a real system and studing its advantages notably for formal verification
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