ALGORITHMS, MANUFACTURES, ENGINEERING, MANUFACTURING processes, NEW product development, BIOMEDICAL engineering, COMPUTER simulation, and VIRTUAL reality
This paper proposes a multi-material virtual prototyping (MMVP) system that integrates the virtual reality (VR) and the layered manufacturing (LM) technologies for digital fabrication of heterogeneous multi-material prototypes for advanced product development and biomedical engineering. The system consists mainly of two algorithms for sequential and concurrent multi-toolpath planning, and a virtual prototyping system. The algorithms adopt a topological hierarchy-sorting algorithm to establish the hierarchy relationship of multi-material slice contours for facilitating toolpath planning of multi-material layered manufacturing (MMLM). Subsequently, the sequential multi-toolpath planning algorithm generates sequential toolpaths that avoid redundant tool movements. To reduce build time further, the concurrent multi-toolpath planning algorithm generates collision-free concurrent toolpaths. Based on the hierarchy information, a bounding box can be adopted to approximate envelopes of contour families of the same material property to simplify detection of tool collisions. The algorithms are integrated to form the MMVP system for planning, stereoscopic simulation, and validation of multi-toolpaths for MMLM. [ABSTRACT FROM AUTHOR]
Cacace, Filippo, Ceri, Stefano, Tanca, Letizia, and Crespi-Reghizzi, Stefano
IEEE Transactions on Software Engineering. Jun92, Vol. 18 Issue 6, p534-546. 13p. 2 Color Photographs, 13 Diagrams.
COMPUTER programming, COMPUTER software, SOFTWARE engineering, ENGINEERING, and COMPUTER systems
This paper presents an environment and a methodology for the design and rapid prototyping of data-intensive software applications; i.e., applications which perform substantial retrieval and update activity on persistent data. In the proposed approach, the application is formally specified using Logres, a database language which combines object-oriented data modeling and rule-based programming. These specifications are translated into Algres, an extended relational algebra, thus yielding a rapid executable prototype. Finally, Algres programs embedded into a conventional programming language interface may be converted to conventional programs operating on a commercial relational system. This methodology helps automate the conversion from declarative requirements to imperative code, performing several tasks fully automatically and reducing the probability of human errors, while integrity constraints and application specifications are expressed in a declarative language, at a very high level of abstraction. [ABSTRACT FROM AUTHOR]
Jard, Claude, Monin, Jean-françois, and Groz, Roland
IEEE Transactions on Software Engineering. Mar88, Vol. 14 Issue 3, p339-352. 14p. 3 Color Photographs, 12 Diagrams.
DISTRIBUTED computing, COMPUTER algorithms, COMPUTER software, SOFTWARE engineering, ENGINEERING, and COMPUTER systems
We report our experience in developing a simulator, called Véda. Véda is a software tool to support designers in protocol modeling and validation. It is basically oriented towards the rapid prototyping of distributed algorithms, and has been available for more than two years. Algorithms are described using an ISO formal description technique, called Estelle. We first give an external view of Véda, and particularly how one can describe service properties and tracing, using a specific feature of Véda, called observation. Then, the development of Véda and its internal structure is presented, emphasizing the use of Prolog as a software engineering tool. Typical uses of Véda that have been made in the relatively large community of its users are sketched. We conclude with a critical analysis of the main features of Véda and how they may have contributed to its success. [ABSTRACT FROM AUTHOR]
DISTRIBUTED computing, PROGRAMMING languages, SOFTWARE engineering, ENGINEERING, COMPUTER software, COMPUTER systems, and PETRI nets
A formal semantics of a prototyping language for hard real-time systems, PSDL, is given. PSDL provides a data flow notation augmented by application-orientation timing and control constraints to describe a system as a hierarchy of networks of processing units communicating via data streams. The semantics of PSDL is defined in terms of algebraic high-level Petri nets. This formalism combines algebraic specifications of abstract data types with process and concurrency concepts of Petri nets. Its data abstraction facilities are used to define the meaning of PSDL data types, while high-level Petri nets serve to model the casual and timing behavior of a system. The net model exposes potential concurrency of computation and makes all synchronization needs implied by timing and control constraints explicit and precise. Time is treated as state of clocks, and clocks are modeled as ordinary system components. The net semantics provides the basis for applying analysis techniques and semantic tools available for high-level Petri nets. [ABSTRACT FROM AUTHOR]
SOFTWARE engineering, ENGINEERING, COMPUTER software, and COMPUTER systems
We explore the use of software transformations for software evolution. Meaning-preserving program transformations have been widely used for program development from a fixed initial specification. We consider a wider class of transformations to support development in which the specification evolves, rather than being fixed in advance. We present a new and general classification of transformations based on their effect on system interfaces, externally observable behavior, and abstraction level of a system description. This classification is used to rearrange chronological derivation sequences containing meaning-changing transformations into lattices containing only meaning-preserving transformations. This paper describes a process model for software evolution, utilizing prototyping techniques, and shows how this class of transformations can be used to support such a process. A set of examples illustrates our ideas. Software tool support and directions for future research are discussed. [ABSTRACT FROM AUTHOR]
DISTRIBUTED computing, COMPUTER software, ENGINEERING, SOFTWARE engineering, and ELECTRONIC systems
In this paper, we describe a specification model that is based on the finite state machine but is distributed. The model allows the user to decompose a large system into separate views. Each view is a complete system in itself, and reveals how the whole system would behave as seen from a certain angle. Put together, the combined views present a complete picture of the whole system. The complexity of a large centralized system is thus distributed and subdued. We then offer a simple execution scheme for our model. Using a high-level state-transition language called SXL, constructs in the model are expressed as pre- and postconditions of transitions. The execution scheme allows all the views in the model to proceed in a parallel but harmonius way, producing a working prototype for the modeled system. [ABSTRACT FROM AUTHOR]
Rapid prototyping and development of in-circuit and FPGA-based emulators as key accelerators for fast time-to-market has resulted in a need for efficient error correction mechanisms. Fabricated or emulated prototypes upon error diagnosis require an effective engineering change (EC). We introduce a novel design methodology which consists of pre- and post-processing techniques that enable EC with minimal perturbation. Initially, in a synthesis preprocessing step, the original design specification is augmented with additional design constraints which ensure flexibility for future correction. Upon alteration of the initial design, a new post-processing technique achieves the desired functionality with near-minimal perturbation of the initially optimized design. The key contribution is a constraint manipulation technique which enables the reduction of an arbitrary EC problem into its corresponding classical synthesis problem. As a result, in both pit- and post- processing for EC, classical synthesis algorithms can be used to enable flexibility and perform the correction process. We demonstrate the developed EC methodology on a set of behavioral and system synthesis tasks. [ABSTRACT FROM AUTHOR]
International Journal of Production Economics. Mar95, Vol. 38 Issue 2-3, p3-13. 11p.
CONCURRENT engineering, RAPID prototyping, JUST-in-time systems, TIME to market (New products), ENGINEERING, and UNCERTAINTY
The engineering process provides technical documents. It can be modeled by extending the Walrasian model. Concurrent engineering involves shortening of lead time and life cycle engineering. Shortening of lead rime can be done by choosing an uncertainty level and using an iterative algorithm to determine optimal concurrency. Cost uncertainty can be included by adding contingency. Cost and time uncertainty in a project can be catered for by providing risk buffers. [ABSTRACT FROM AUTHOR]
The article focuses on the use of the Epilog Legend 36EXT laser cutter by the engineering department of Edison Nation for prototyping products. The laser beam of the machine helps in cutting complex two dimensional shapes or engraving graphics or images. The cutting is achieved with the use of different software.
RAPID prototyping, MANUFACTURING processes, CONCURRENT engineering, ENGINEERING, and NEW product development
The article provides information on the developments surrounding rapid injection molding prototyping. Rapid injection molding is more than just a machine. rapid injection molding can save money as well. Some injection-molding providers furnish inspection services. Furthermore, it has been noted that the use of rapid anything is not slowing.
RAPID prototyping, MANUFACTURING processes, TECHNOLOGICAL innovations, ENGINEERING, and THREE-dimensional printing
The author explores his views on the implications of additive layer manufacturing or 3D printing. The technique's ability to use different materials from conventional manufacturing processes, and assemble them layer by layer into an intricate design derived digitally is highlighted. The technology is expected to change the way the engineers make things and change the things they make.