35,472 research outputs found
A requirements engineering framework for integrated systems development for the construction industry
Computer Integrated Construction (CIC) systems are computer environments through which
collaborative working can be undertaken. Although many CIC systems have been developed to demonstrate the
communication and collaboration within the construction projects, the uptake of CICs by the industry is still
inadequate. This is mainly due to the fact that research methodologies of the CIC development projects are
incomplete to bridge the technology transfer gap. Therefore, defining comprehensive methodologies for the
development of these systems and their effective implementation on real construction projects is vital.
Requirements Engineering (RE) can contribute to the effective uptake of these systems because it drives the
systems development for the targeted audience. This paper proposes a requirements engineering approach for
industry driven CIC systems development. While some CIC systems are investigated to build a broad and deep
contextual knowledge in the area, the EU funded research project, DIVERCITY (Distributed Virtual Workspace
for Enhancing Communication within the Construction Industry), is analysed as the main case study project
because its requirements engineering approach has the potential to determine a framework for the adaptation of
requirements engineering in order to contribute towards the uptake of CIC systems
Instant restore after a media failure
Media failures usually leave database systems unavailable for several hours
until recovery is complete, especially in applications with large devices and
high transaction volume. Previous work introduced a technique called
single-pass restore, which increases restore bandwidth and thus substantially
decreases time to repair. Instant restore goes further as it permits read/write
access to any data on a device undergoing restore--even data not yet
restored--by restoring individual data segments on demand. Thus, the restore
process is guided primarily by the needs of applications, and the observed mean
time to repair is effectively reduced from several hours to a few seconds.
This paper presents an implementation and evaluation of instant restore. The
technique is incrementally implemented on a system starting with the
traditional ARIES design for logging and recovery. Experiments show that the
transaction latency perceived after a media failure can be cut down to less
than a second and that the overhead imposed by the technique on normal
processing is minimal. The net effect is that a few "nines" of availability are
added to the system using simple and low-overhead software techniques
Formal development and evaluation of narrow passageway system operations
This study applies a new intelligent transportation methodology for transforming informal operations
concepts for narrow passageway systems into system-level designs, which will formal enough to support
automated validation of anticipated component- and system-level behaviours. Models and specifications
of behaviour are formally designed as labelled transition systems. Each object is the management system
is assumed to have behaviour that can be defined by a finite state machine; thus, the waterway
management system architecture is modelled as a network of communicating finite state machines.
Architecture-level behaviours are validated using the Labelled Transition System Analyzer (LTSA). We
exercise the methodology by working step by step through the synthesis and validation of a high-level
behaviour model for a vessel passing through a waterway network (i.e., canal)
HLS-Based Methodology for Fast Iterative Development Applied to Elliptic Curve Arithmetic
International audienceHigh-Level Synthesis (HLS) is used by hardware developers to achieve higher abstraction in circuit descriptions. In order to shorten the hardware development time via HLS, we present an adjustment of the Iterative and Incremental Design (IID) methodology, frequently used in software development. In particular, our methodology is relevant for the development of applications with unusual complexity: the method was applied here to the development of large modular arithmetic, commonly used for cryptography applications (e.g., Elliptic Curves). Rapid feedback on circuit characteristics is used to evaluate deep architectural changes in short time, greatly reducing the time-to-market with respect to hand-made designs. In addition, our approach is highly flexible, since the same generic high-level description can be used to produce an entire set of circuits, each with different area/performance trade-offs. Thanks to the proposed approach, any change to the initial specification (e.g., the curve used) is also very fast, while it may require a large effort in the case of hand-made designs
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