Successful bid preparation requires cooperation among specialists of different domains. Efficient cooperation between employees of different departments requires the use of a computerized system capable of supporting ...
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Successful bid preparation requires cooperation among specialists of different domains. Efficient cooperation between employees of different departments requires the use of a computerized system capable of supporting distributed processes on possibly different hardware platforms. This paper presents an approach for the development of a software system designed to support the pre-sales phase of companies producing capital goods. Within the ESPRIT project ''BIDPREP'' (No. 7131) enterprises, research institutes and a software vendor cooperate in order to develop a generally applicable solution. In order to coordinate the distributed work, a modularization concept has to be followed. The system architecture follows object-oriented principles. As its distribution mechanism, the Common Object Request Broker Architecture (CORBA) has been chosen. CORBA provides a high-level protocol for object distribution and communication that allows a precise module interface specification. The gained experiences and its benefits are described.
Erlang is a functional programming language developed by Ericsson Telecom, which is particularly well suited for implementing concurrent processes. In this paper we show how methods from the area of term rewriting are...
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Erlang is a functional programming language developed by Ericsson Telecom, which is particularly well suited for implementing concurrent processes. In this paper we show how methods from the area of term rewriting are presently used at Ericsson. To verify properties of processes, such a property is transformed into a termination problem of a conditional term rewriting system (CTRS). Subsequently, this termination proof can be performed automatically using dependency pairs. The paper illustrates how the dependency pair technique can be applied for termination proofs of conditional TRSs. Secondly, we present three refinements of this technique, viz. narrowing, rewriting, and instantiating dependency pairs. These refinements are not only of use in the industrial applications sketched in this paper, but they are generally applicable to arbitrary (C)TRSs. Thus, in this way dependency pairs can be used to prove termination of even more (C)TRSs automatically.
Three notations for concurrent programming are compared, namely CSP, Ada, and monitors. CSP is an experimental language for exploring structuring concepts in concurrent programming. Ada is a general-purpose language w...
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Three notations for concurrent programming are compared, namely CSP, Ada, and monitors. CSP is an experimental language for exploring structuring concepts in concurrent programming. Ada is a general-purpose language with concurrent programming facilities. Monitors are a construct for managing access by concurrent processes to shared resources. We start by comparing "lower-level" communication, synchronization, and nondeterminism in CSP and Ada and then examine "higher-level" module interface properties of Ada tasks and monitors.
Organizations today face increasing pressures to integrate their processes across disparate divisions and functional units, in order to remove inefficiencies as well as to enhance manageability. Process integration in...
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Organizations today face increasing pressures to integrate their processes across disparate divisions and functional units, in order to remove inefficiencies as well as to enhance manageability. Process integration involves two major types of changes to process structure: (1) synthesizing processes from separate but interdependent subprocesses, and (2) decomposing aggregate processes into distinct subprocesses that are more manageable. We present an approach to facilitate this type of synthesis and decomposition through formal analysis of process structure using a mathematical structure called a metagraph.
This paper is an exploration of the dynamics of technical change in medicine. We argue that innovation in medicine is a process that is distributed across time, space and epistemic and institutional domains;that it en...
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This paper is an exploration of the dynamics of technical change in medicine. We argue that innovation in medicine is a process that is distributed across time, space and epistemic and institutional domains;that it entails the entrepreneurial effort of creative individuals as well as the emergence of correlated understanding among heterogeneous agents whose rules of interaction are contingently instituted in socio-economic systems along unfolding scientific and technological trajectories. We illustrate our arguments through an in-depth analysis of a major ophthalmologic innovation - the intra-ocular lens - that has literally transformed the treatment of cataract in the developed world and has the potential to do so in many developing countries. We investigate the advancement of clinical knowledge about the disease, the development of effective technological capabilities and the co-evolution of the supply capacity and demand of a micro-innovation system emerged along a specific sequence of interrelated problems, and associated solutions, which engaged scientists, technicians, practitioners, regulators and patients alike over a period of around three decades. (c) 2005 Elsevier B.V. All rights reserved.
This article presents a new mathematical model of parallel programs that can be used, in particular, for verification of parallel programs presented on a certain subset of the MPI parallel programming interface. The m...
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This article presents a new mathematical model of parallel programs that can be used, in particular, for verification of parallel programs presented on a certain subset of the MPI parallel programming interface. The model is based on the concepts of sequential and distributed processes. A parallel program is modeled as a distributed process within which sequential processes communicate by asynchronously sending and receiving messages over channels. The main advantage of the proposed model is its capability of modeling and verifying parallel programs that generate an indefinite number of sequential processes. To illustrate the model's performance, an example of its application to verification of an MPI matrix multiplication program is described.
Recent hardware technology advances have made feasible the design of multiprocessor computer systems which have the philosophy of being ''available'' most of the time instead of being ''utilize...
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Recent hardware technology advances have made feasible the design of multiprocessor computer systems which have the philosophy of being ''available'' most of the time instead of being ''utilized'' most of the time. To realize the potential of such networks, it is necessary to have a discipline for concurrent programming which would allow the development of well-structured, reliable, and efficient concurrent *** communication port is a new language concept for writing high-quality efficient concurrent programs on distributed processor networks. Such a network can contain an arbitrary number of processors with private storage communicating via explicit message passing. The communication port encompasses 2 language properties: communication non-determinism and communication disconnect time. Figure.
Linking many independent microprocessors with distributed storage is frequently desirable. A requirement for successful linkage is a distributed programming language capable of being used in well-structured, reliable...
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Linking many independent microprocessors with distributed storage is frequently desirable. A requirement for successful linkage is a distributed programming language capable of being used in well-structured, reliable, and efficient programs. Guarded Procedure (GP), a new approach to distributed programming, specifies communication and synchronization among software components, enabling processes to proceed in parallel. Objectives in the design of GP are: 1. high system throughput, 2. the ability to call subroutines, and 3. simplicity for easy implementation. Examples of applications of GP are given in the solution of familiar programming exercises.
The cellular automata model was described by John von Neumann and his friends in the 1950s as a representation of information processing in multicellular tissue. With crystalline arrays of cells and synchronous activi...
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The cellular automata model was described by John von Neumann and his friends in the 1950s as a representation of information processing in multicellular tissue. With crystalline arrays of cells and synchronous activity, it missed the mark (Stark and Hughes, BioSystems 55:107-117, 2000). Recently, amorphous computing, a valid model for morphogenesis in multicellular information processing, has begun to fill the void. Through simple examples and elementary mathematics, this paper begins a computation theory for this important new direction.
Discussed is a distributed system based on communication among disjoint processes, where each process is capable of achieving a post-condition of its local space in such a way that the conjunction of local post-condit...
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