Pub Date : 2000-01-19DOI: 10.1109/EMPDP.2000.823398
A. Puliafito, O. Tomarchio
Mobile agents represent a new communication paradigm which has recently obtained a great deal of attention from researchers and practitioners. Interesting applications exist in the fields of distributed systems management, mobility and information retrieval. Although widely recognized as a crucial point to be addressed, security has not been pursued in a satisfactory way yet. Most of all the existing software environments for agent programming do not offer security features or provide only partial implementations. We propose a security schema for mobile agents and describe its implementation inside the MAP platform. Some experimental results are also provided to evaluate the overhead introduced from the adoption of the proposed security mechanism.
{"title":"Security mechanisms for the MAP agent system","authors":"A. Puliafito, O. Tomarchio","doi":"10.1109/EMPDP.2000.823398","DOIUrl":"https://doi.org/10.1109/EMPDP.2000.823398","url":null,"abstract":"Mobile agents represent a new communication paradigm which has recently obtained a great deal of attention from researchers and practitioners. Interesting applications exist in the fields of distributed systems management, mobility and information retrieval. Although widely recognized as a crucial point to be addressed, security has not been pursued in a satisfactory way yet. Most of all the existing software environments for agent programming do not offer security features or provide only partial implementations. We propose a security schema for mobile agents and describe its implementation inside the MAP platform. Some experimental results are also provided to evaluate the overhead introduced from the adoption of the proposed security mechanism.","PeriodicalId":128020,"journal":{"name":"Proceedings 8th Euromicro Workshop on Parallel and Distributed Processing","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116165477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2000-01-19DOI: 10.1109/EMPDP.2000.823395
P. Dembinski
The paper describes a randomized distributed enumeration algorithm which (in contrast to deterministic solutions) works for all network topologies and with fully asynchronous communication. The algorithm correctness and efficiency are considered. The expected execution time is of the order of the time needed for a broadcast.
{"title":"Distributed and randomized enumeration","authors":"P. Dembinski","doi":"10.1109/EMPDP.2000.823395","DOIUrl":"https://doi.org/10.1109/EMPDP.2000.823395","url":null,"abstract":"The paper describes a randomized distributed enumeration algorithm which (in contrast to deterministic solutions) works for all network topologies and with fully asynchronous communication. The algorithm correctness and efficiency are considered. The expected execution time is of the order of the time needed for a broadcast.","PeriodicalId":128020,"journal":{"name":"Proceedings 8th Euromicro Workshop on Parallel and Distributed Processing","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122590351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2000-01-19DOI: 10.1109/EMPDP.2000.823394
A. N. Spyropoulos, J. Palyvos, A. Boudouvis
In the last decade distributed processing on clusters of PCs and workstations have become a popular alternative way for parallel computations due to their low cost compared to parallel supercomputers. The most important factor that limits the parallel efficiency of an algorithm running on a cluster is the low bandwidth and high latency of the network that interconnects the computers. Specially designed parallel algorithms must be applied that have low communication overhead. A parallel method on Galerkin/finite element computations on clusters of PCs and workstations is presented. This method is based on a parallel preconditioned Krylov-type iterative solver for the solution of large, sparse and nonsymmetric equation systems. Two important aspects of the method are addressed: the storage of the coefficient matrix of the system and of the preconditioning matrix, and the performance of the preconditioner. The matrix storage affects the parallel efficiency of the matrix vector product. The preconditioner contributes to the parallel efficiency and is of critical importance for the convergence rate of the iterative method. The performance of the method is analysed in terms of parallel speedup, storage efficiency and convergence rate.
{"title":"Finite element computations on cluster of PCs and workstations","authors":"A. N. Spyropoulos, J. Palyvos, A. Boudouvis","doi":"10.1109/EMPDP.2000.823394","DOIUrl":"https://doi.org/10.1109/EMPDP.2000.823394","url":null,"abstract":"In the last decade distributed processing on clusters of PCs and workstations have become a popular alternative way for parallel computations due to their low cost compared to parallel supercomputers. The most important factor that limits the parallel efficiency of an algorithm running on a cluster is the low bandwidth and high latency of the network that interconnects the computers. Specially designed parallel algorithms must be applied that have low communication overhead. A parallel method on Galerkin/finite element computations on clusters of PCs and workstations is presented. This method is based on a parallel preconditioned Krylov-type iterative solver for the solution of large, sparse and nonsymmetric equation systems. Two important aspects of the method are addressed: the storage of the coefficient matrix of the system and of the preconditioning matrix, and the performance of the preconditioner. The matrix storage affects the parallel efficiency of the matrix vector product. The preconditioner contributes to the parallel efficiency and is of critical importance for the convergence rate of the iterative method. The performance of the method is analysed in terms of parallel speedup, storage efficiency and convergence rate.","PeriodicalId":128020,"journal":{"name":"Proceedings 8th Euromicro Workshop on Parallel and Distributed Processing","volume":"40 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131471817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2000-01-19DOI: 10.1109/EMPDP.2000.823417
T. Andronikos, N. Koziris
The n-dimensional grid is one of the most representative patterns of data flow in parallel computation. Many scientific algorithms, which require nearest neighbor communication in a lattice space, are modeled by a task graph with the properties of a simple or enhanced grid. In this paper we consider an enhanced model of the n-dimensional grid by adding extra diagonal edges and allowing unequal boundaries for each dimension. First, we calculate the optimal makespan for the generalized UET-UCT (Unit Execution Time-Unit Communication Time) grid topology and then, we establish the minimum number of processors required, to achieve the optimal makespan. We present the optimal time schedule, using unbounded and bounded number of processors, without allowing task duplication. This paper proves that UET-UCT scheduling of generalized n-dimensional grids into fixed number of processors is low complexity tractable.
{"title":"Optimal scheduling for UET-UCT grids into fixed number of processors","authors":"T. Andronikos, N. Koziris","doi":"10.1109/EMPDP.2000.823417","DOIUrl":"https://doi.org/10.1109/EMPDP.2000.823417","url":null,"abstract":"The n-dimensional grid is one of the most representative patterns of data flow in parallel computation. Many scientific algorithms, which require nearest neighbor communication in a lattice space, are modeled by a task graph with the properties of a simple or enhanced grid. In this paper we consider an enhanced model of the n-dimensional grid by adding extra diagonal edges and allowing unequal boundaries for each dimension. First, we calculate the optimal makespan for the generalized UET-UCT (Unit Execution Time-Unit Communication Time) grid topology and then, we establish the minimum number of processors required, to achieve the optimal makespan. We present the optimal time schedule, using unbounded and bounded number of processors, without allowing task duplication. This paper proves that UET-UCT scheduling of generalized n-dimensional grids into fixed number of processors is low complexity tractable.","PeriodicalId":128020,"journal":{"name":"Proceedings 8th Euromicro Workshop on Parallel and Distributed Processing","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131772955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2000-01-19DOI: 10.1109/EMPDP.2000.823422
Paul-Jean Cagnard
We present a synchronous parallel programming model designed for massively parallel fine grained applications such as cellular automata, finite element methods or partial differential equations. In this model we assume that the number of parallel processes in a program is much larger than the number of processors of the machine on which it is run. We present the computational model and the communication model. We introduce the virtual cellular machine, an abstract machine implementing this programming model which requires means to simulate efficiently the execution of many processes on a single processor; and to use the available communication bandwidth efficiently. Finally, we show an example program written in a prototype language designed for programming the virtual machine.
{"title":"The parallel cellular programming model","authors":"Paul-Jean Cagnard","doi":"10.1109/EMPDP.2000.823422","DOIUrl":"https://doi.org/10.1109/EMPDP.2000.823422","url":null,"abstract":"We present a synchronous parallel programming model designed for massively parallel fine grained applications such as cellular automata, finite element methods or partial differential equations. In this model we assume that the number of parallel processes in a program is much larger than the number of processors of the machine on which it is run. We present the computational model and the communication model. We introduce the virtual cellular machine, an abstract machine implementing this programming model which requires means to simulate efficiently the execution of many processes on a single processor; and to use the available communication bandwidth efficiently. Finally, we show an example program written in a prototype language designed for programming the virtual machine.","PeriodicalId":128020,"journal":{"name":"Proceedings 8th Euromicro Workshop on Parallel and Distributed Processing","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128843063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2000-01-19DOI: 10.1109/EMPDP.2000.823424
J. Sahuquillo, A. Pont
As processor speed continues, the gap between the processor cycle and the memory subsystem cycle is expected to grow. One solution to this growing problem is to maximize the first level (LI) cache hit ratio, therefore the mean memory access time call decrease. Several studies have been made in order to manage more efficiently the LI data cache, both in uniprocessor and in multiprocessor systems. These studies seek two main objectives, to increase the LI hit ratio and to reduce the chip area occupied by these caches. In this work we present two new different approaches for increasing the LI hit ratio in multiprocessor systems and we compare with a conventional organization. Performance evaluation and hardware cost of these organizations are also calculated and compared with the cost incurred by the most common organization used.
{"title":"Two management approaches of the split data cache in multiprocessor systems","authors":"J. Sahuquillo, A. Pont","doi":"10.1109/EMPDP.2000.823424","DOIUrl":"https://doi.org/10.1109/EMPDP.2000.823424","url":null,"abstract":"As processor speed continues, the gap between the processor cycle and the memory subsystem cycle is expected to grow. One solution to this growing problem is to maximize the first level (LI) cache hit ratio, therefore the mean memory access time call decrease. Several studies have been made in order to manage more efficiently the LI data cache, both in uniprocessor and in multiprocessor systems. These studies seek two main objectives, to increase the LI hit ratio and to reduce the chip area occupied by these caches. In this work we present two new different approaches for increasing the LI hit ratio in multiprocessor systems and we compare with a conventional organization. Performance evaluation and hardware cost of these organizations are also calculated and compared with the cost incurred by the most common organization used.","PeriodicalId":128020,"journal":{"name":"Proceedings 8th Euromicro Workshop on Parallel and Distributed Processing","volume":"212 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128166560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2000-01-19DOI: 10.1109/EMPDP.2000.823404
K. Sandkuhl, Burkhard Messer
Standard groupware products do not fulfill the specific requirements of various application areas, due to technical restrictions, lack of flexibility or non-availability of adapted interfaces. In view of this situation, development of groupware products for specialized application areas will continue to be necessary. Our approach is to support this kind of software development project by providing: a reference architecture for groupware applications as a guideline for software developers; reusable components and services; and design and architecture patterns. This paper presents a view concept for software architectures, a global reference architecture for groupware applications and an example from the application field of Web-publishing.
{"title":"Towards reference architectures for distributed groupware applications","authors":"K. Sandkuhl, Burkhard Messer","doi":"10.1109/EMPDP.2000.823404","DOIUrl":"https://doi.org/10.1109/EMPDP.2000.823404","url":null,"abstract":"Standard groupware products do not fulfill the specific requirements of various application areas, due to technical restrictions, lack of flexibility or non-availability of adapted interfaces. In view of this situation, development of groupware products for specialized application areas will continue to be necessary. Our approach is to support this kind of software development project by providing: a reference architecture for groupware applications as a guideline for software developers; reusable components and services; and design and architecture patterns. This paper presents a view concept for software architectures, a global reference architecture for groupware applications and an example from the application field of Web-publishing.","PeriodicalId":128020,"journal":{"name":"Proceedings 8th Euromicro Workshop on Parallel and Distributed Processing","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129087441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2000-01-19DOI: 10.1109/EMPDP.2000.823405
T. Guinan, Gregory M. P. O'Hare, N. Doikov
We present the details of the ENTER (Environment which Totally Envelops the useR) system. The ENTER system seeks to provide a totally, immersive 3-dimensional environment which is highly, configurable and personalised based on the perceived needs of an individual user. The use of agent-oriented modelling and design techniques has lead to a versatile and flexible system within which the constituent agents collaborate to realise the system aims. The facility to dynamically reconfigure virtual worlds controlled by the agent entities lends to the technology being applicable for differing immersive environments. This system has in the first instance been cast in the arena of virtual shopping malls, but of course this represents but one potential application domain.
{"title":"ENTER: the personalisation and contextualisation of 3-dimensional worlds","authors":"T. Guinan, Gregory M. P. O'Hare, N. Doikov","doi":"10.1109/EMPDP.2000.823405","DOIUrl":"https://doi.org/10.1109/EMPDP.2000.823405","url":null,"abstract":"We present the details of the ENTER (Environment which Totally Envelops the useR) system. The ENTER system seeks to provide a totally, immersive 3-dimensional environment which is highly, configurable and personalised based on the perceived needs of an individual user. The use of agent-oriented modelling and design techniques has lead to a versatile and flexible system within which the constituent agents collaborate to realise the system aims. The facility to dynamically reconfigure virtual worlds controlled by the agent entities lends to the technology being applicable for differing immersive environments. This system has in the first instance been cast in the arena of virtual shopping malls, but of course this represents but one potential application domain.","PeriodicalId":128020,"journal":{"name":"Proceedings 8th Euromicro Workshop on Parallel and Distributed Processing","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125452464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2000-01-19DOI: 10.1109/EMPDP.2000.823434
Juan P. Castellano, David Cruz Sánchez Rodríguez, Onassis Cazorla, Álvaro Suárez Sarmiento
In the last years, multimedia systems are present in an ever increasing number of applications. A software implementation often can not satisfy system timing constraints. This problem can be solved by adding specific hardware to the system. Lately, it has been developed some design methodologies for this type of hardware/software systems. Our research group have developed a hardware/software codesign environment named GACSYS (GAC's Codesign System) for designing this type of systems. In this article, we present our Hw/Sw partitioning tool. Main contribution of our tool is the following: it supports process-level pipelining and takes into account system power consumption. Thus, system designer can explore the design space to make new latency, area and power trade-offs.
{"title":"Pipelining-based tradeoffs for hardware/software codesign of multimedia systems","authors":"Juan P. Castellano, David Cruz Sánchez Rodríguez, Onassis Cazorla, Álvaro Suárez Sarmiento","doi":"10.1109/EMPDP.2000.823434","DOIUrl":"https://doi.org/10.1109/EMPDP.2000.823434","url":null,"abstract":"In the last years, multimedia systems are present in an ever increasing number of applications. A software implementation often can not satisfy system timing constraints. This problem can be solved by adding specific hardware to the system. Lately, it has been developed some design methodologies for this type of hardware/software systems. Our research group have developed a hardware/software codesign environment named GACSYS (GAC's Codesign System) for designing this type of systems. In this article, we present our Hw/Sw partitioning tool. Main contribution of our tool is the following: it supports process-level pipelining and takes into account system power consumption. Thus, system designer can explore the design space to make new latency, area and power trade-offs.","PeriodicalId":128020,"journal":{"name":"Proceedings 8th Euromicro Workshop on Parallel and Distributed Processing","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126738264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2000-01-19DOI: 10.1109/EMPDP.2000.823390
Zdzislaw Szczerbinski, S. Kowalik
We present research into parallelizing the zone-parallel method of global optimization. The method belongs to the class of genetic algorithms and is briefly, described in the paper upon introduction to genetic algorithms, parallelization models for genetic algorithms are presented. The subsequent part of the paper is devoted to the global optimization problem of finding sources of tremors in coal mines. First, a short description of the S-P method for localizing hypocenters of tremors is given; the method requires minimizing the error function for hypocenter location. Next, a practical coal-mining example is given where data on a tremor are collected by seismometers and the location of the the hypocenter is found by employing the zone parallel method. Experimental results are presented which were obtained from implementing both the sequential and parallel versions of the zone-parallel method in a local area network of Sun Ultra workstations. The results show suitability of the island model of parallelization for this optimization method as well as disproving the usefulness of the master-slave model.
{"title":"Parallelizing a global optimization method in a distributed-memory environment","authors":"Zdzislaw Szczerbinski, S. Kowalik","doi":"10.1109/EMPDP.2000.823390","DOIUrl":"https://doi.org/10.1109/EMPDP.2000.823390","url":null,"abstract":"We present research into parallelizing the zone-parallel method of global optimization. The method belongs to the class of genetic algorithms and is briefly, described in the paper upon introduction to genetic algorithms, parallelization models for genetic algorithms are presented. The subsequent part of the paper is devoted to the global optimization problem of finding sources of tremors in coal mines. First, a short description of the S-P method for localizing hypocenters of tremors is given; the method requires minimizing the error function for hypocenter location. Next, a practical coal-mining example is given where data on a tremor are collected by seismometers and the location of the the hypocenter is found by employing the zone parallel method. Experimental results are presented which were obtained from implementing both the sequential and parallel versions of the zone-parallel method in a local area network of Sun Ultra workstations. The results show suitability of the island model of parallelization for this optimization method as well as disproving the usefulness of the master-slave model.","PeriodicalId":128020,"journal":{"name":"Proceedings 8th Euromicro Workshop on Parallel and Distributed Processing","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127787696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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