In order to overcome the difficulties in analyzing complex physical systems with Petri nets, two new decomposition methods for structure-complex Petri net are presented based on an index function defined on the place ...
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In order to overcome the difficulties in analyzing complex physical systems with Petri nets, two new decomposition methods for structure-complex Petri net are presented based on an index function defined on the place and transition set respectively. The decomposition method based on the indexes of places is suitable for analyzing the behavior synchronization between systems, with which a structure- omplex Petri net is decomposed into a set of S-Nets. The decomposition method based on the indexes of transitions is suitable for analyzing the resource sharing between systems, with which a structure-complex Petri net is decomposed into a set of T-Nets. The relationships between the decomposition structure-simple subnets and the original structure-complex systems are proved, and the properties of the original system can be analyzed based on the structure- simple S-Nets or T-Nets.
Cellular Automata (CA) models, initially studied by John von Neumann, have been developed by numerous researchers and applied in both academic and scientific fields. Thanks to their local and independent rules, simula...
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We have designed a Compiler Algorithm Language (CAL) to provide compiler writers with a language which is close to actual algorithmic notation. In this work, we have developed an interpreter and debugger for CAL which...
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ISBN:
(纸本)9780889866560
We have designed a Compiler Algorithm Language (CAL) to provide compiler writers with a language which is close to actual algorithmic notation. In this work, we have developed an interpreter and debugger for CAL which can be used by researchers for algorithm testing. We also provide a compiler that can translate CAL programs to C code which can be plugged elsewhere. We have provided a Graphical User Interface to make it convenient for the user to use the interpreter and compiler. Another feature of our system is web-enabling of the entire project so that a remote user would not have to download the entire code. Altogether, we have attempted to save the compiler writers from the trouble of writing lengthy programs for their algorithms.
Summary form only given. This paper describes a parallel debugger and the related debugging support implemented for CHARM++, a data-driven parallel programming language. Because we build extensive debugging support in...
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Summary form only given. This paper describes a parallel debugger and the related debugging support implemented for CHARM++, a data-driven parallel programming language. Because we build extensive debugging support into the parallel runtime system, applications can be debugged at a very high level.
This paper identifies three categories of safety risks posed by allowing multiple users to engage with small Unmanned Aerial systems (sUAS) and offers five recommendations on how to reduce or mitigate these vulnerabil...
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Reprogramming is an essential service for wireless sensor networks. Authenticating reprogramming process is important as sensors need to verify that the code image is truly from a trusted source. There are two ways to...
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Reprogramming is an essential service for wireless sensor networks. Authenticating reprogramming process is important as sensors need to verify that the code image is truly from a trusted source. There are two ways to achieve authentication: public key based and symmetric key based. Although previous work has shown that public key authentication is feasible on sensor nodes if used sparingly, it is still quite expensive compared to symmetric key based approach. In this paper, we propose a symmetric key based protocol for authenticating reprogramming process. Our protocol is based on the secret instantiation algorithm from, which requires only O(log n) keys to be maintained at each sensor. We integrate this algorithm with the existing reprogramming protocol. Through simulation, we show that it is able to authenticate reprogramming process at very low communication cost, and has very short delay.
Over the academic year 2022–23, we discussed the teaching of software performance engineering with more than a dozen faculty across North America and beyond. Our outreach was centered on research-focused faculty with...
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ISBN:
(数字)9798350364606
ISBN:
(纸本)9798350364613
Over the academic year 2022–23, we discussed the teaching of software performance engineering with more than a dozen faculty across North America and beyond. Our outreach was centered on research-focused faculty with an existing interest in this course material. These discussions revealed an enthusiasm for making software performance engineering a more prominent part of a curriculum for computer scientists and engineers. Here, we discuss how MIT's longstanding efforts in this area may serve as a launching point for community development of a software performance engineering curriculum, challenges in and solutions for providing the necessary infrastructure to universities, and future directions.
Modern grids have become very complex by their size and their heterogeneity. It makes the deployment and maintenance of systems a difficult task requiring lots of efforts from administrators and programmers. Our goal ...
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Modern grids have become very complex by their size and their heterogeneity. It makes the deployment and maintenance of systems a difficult task requiring lots of efforts from administrators and programmers. Our goal is to investigate the concepts that underlie autonomic computing systems, especially for grid environment. We believe that peer-to-peer overlay networks are a valuable basis to support some of the main issues of autonomic computing in the particular case of grids. This article presents the construction of an autonomous, decentralized, scalable, and efficient grid monitoring system. The components of this application negotiate through a peer-to-peer network in order to provide autonomic behaviors and exchange data. We present a solution based on a gossip broadcast protocol upon a hierarchical, directed, and acyclic graph to rapidly diffuse information in the system while limiting the number of messages. The software architecture is detailed, and then the first results of its performance are presented and analyzed.
Optimal scheduling of tasks of a directed acyclic graph (DAG) onto a set of processors is a strong NP-hard problem. In this paper we present a scheduling scheme called TDS to schedule tasks of a DAG onto a heterogeneo...
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Optimal scheduling of tasks of a directed acyclic graph (DAG) onto a set of processors is a strong NP-hard problem. In this paper we present a scheduling scheme called TDS to schedule tasks of a DAG onto a heterogeneous system. This models a network of workstations, with processors of varying computing power. The primary objective of this scheme is to minimize schedule length and scheduling time itself. The existing task duplication based scheduling scheme is primarily done for totally homogeneous systems. We compare the performance of this algorithm with an existing scheduling scheme for heterogeneous processors called BIL. In initial simulations TDS has been observed to generate scheduling lengths shorter than that of BIL, for communication-to-computation cost ratios (CCR) of 0.2 to 1. Moreover TDS is far more superior than BIL as far as scheduling time is concerned.
Conventional approaches for implementing barrier synchronization in large scale systems result in long synchronization times due to memory and network contention. The authors present some applications of a very simple...
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Conventional approaches for implementing barrier synchronization in large scale systems result in long synchronization times due to memory and network contention. The authors present some applications of a very simple barrier hardware that allows barrier synchronizations to be performed within a few processor cycles. The low latency of this barrier synchronizer and its ability to allow dynamic participation permits several rather unconventional applications like low-latency software combining, scans and determination of extremum values in constant time. This paper presents these applications.< >
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