Circuit simulation has proven to be one of the most important computer aided design (CAD) methods for the analysis and validation of integrated circuit designs. A popular approach to describing circuits for simulation...
ISBN:
(纸本)9780769506678
Circuit simulation has proven to be one of the most important computer aided design (CAD) methods for the analysis and validation of integrated circuit designs. A popular approach to describing circuits for simulation purposes is to use a hardware description language such as VHDL. Similar efforts have also been carried out in the analog domain that has led to tools such as SPICE. However, with the growing trend of hardware designs that contain both analog and digital components, design environments that seamlessly integrate analog and digital circuitry are needed. simulation of such circuit is however, exacerbated by the higher resource (CPU and memory) demands that arise when analog and digital models are integrated in a mixed-mode (analog and digital) simulation. One solution to this problem is to use PDES algorithms on a distributed platform. However, a synchronization interface between the analog and digital simulation environment is required to achieve integrated mixed-mode simulation. In this paper, we present the issues involved in the construction of synchronization protocols which support mixed-mode simulation in a distributedsimulation environment. The proposed synchronization protocols provide an interface between an optimistic (Time Warp based) discrete-event simulation kernel and any continuous time simulation kernel. Empirical and formal analyses were conducted to ensure correctness and completeness of the protocols and the results of these analyses are also presented.
Computational Grids have become an important and popular computing platform for both scientific and commercial distributed computing communities. However, users of such systems typically find achievement of applicatio...
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Computational Grids have become an important and popular computing platform for both scientific and commercial distributed computing communities. However, users of such systems typically find achievement of application execution performance remains challenging. Although Grid infrastructures such as Legion and Globus provide basic resource selection functionality, work allocation functionality, and scheduling mechanisms, applications must interpret system performance information in terms of their own requirements in order to develop performance-efficient schedules. We describe a new high-performance scheduler that incorporates dynamic system information, application requirements, and a detailed performance model in order to create performance efficient schedules. While the scheduler is designed to provide improved performance for a magneto hydrodynamics simulation in the Legion Computational Grid infrastructure, the design is generalizable to other systems and other data-parallel, iterative codes. We describe the adaptive performance model, resource selection strategies, and scheduling policies employed by the scheduler. We demonstrate the improvement in application performance achieved by the scheduler in dedicated and shared Legion environments.
In a large-scale distributedsimulation with thousands of dynamic objects, efficient communication of data among these objects is an important issue. The broadcasting mechanism specified by the distributed Interactive...
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ISBN:
(纸本)9780769506678
In a large-scale distributedsimulation with thousands of dynamic objects, efficient communication of data among these objects is an important issue. The broadcasting mechanism specified by the distributed Interactive simulation (DIS) standards is not suitable for large scale distributed *** the High Level Architecture (HLA) paradigm, the Runtime Infrastructure (RTI) provides a set of services, such as data distribution management (DDM) among federates. The goal of the DDM module in RTI is to make the data communication more efficient by sending the data only to those federates that need the data, as opposed to the broadcasting mechanism employed by *** DDM schemes have appeared in the literature. In this paper, we discuss grid-based DDM and develop a DDM model that uses grids for matching the publishing/subscription regions, and for data filtering. We show that appropriate choice of the grid-cell size is crucial in obtaining good performance. We develop an analytical model and derive a formula for identifying the optimal cell size in grid-based DDM.
We have parallelized the Iowa Logic Simulator, a gate-level fine-grained discrete-event simulator, by employing an optimistic algorithm framework based on a global event queue implemented as a parallel heap. The origi...
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ISBN:
(纸本)9780769506678
We have parallelized the Iowa Logic Simulator, a gate-level fine-grained discrete-event simulator, by employing an optimistic algorithm framework based on a global event queue implemented as a parallel heap. The original code and the basic data structures of the serial simulator remained unchanged. Wrapper data structures for the logical processes (gates) and the events are created to allow rollbacks, all the earliest events at each logical processes are stored into the parallel heap, and multiple earliest events are simulated repeatedly by invoking the simulate function of the serial simulator. The parallel heap allowed extraction of hundreds to thousands of earliest events in each queue access. On a bus-based shared-memory multiprocessor, simulation of synthetic circuits with 250,000 gates yielding speedups of 3.3 employing five processors compared to the serial execution time of the Iowa Logic Simulator, and limited the number of rollbacks to within 2,000. The basic steps of parallelization are well-defined and general enough to be employable on other discrete-event simulators.
Load balancing is a crucial factor in achieving good performance for parallel discrete event simulations. In this paper, we present a load balancing scheme that combines both static partitioning and dynamic load balan...
ISBN:
(纸本)9780769506678
Load balancing is a crucial factor in achieving good performance for parallel discrete event simulations. In this paper, we present a load balancing scheme that combines both static partitioning and dynamic load balancing. The static partitioning scheme maps simulation objects to logical processes before simulation starts while the dynamic load balancing scheme attempt to balance the load during runtime. The static scheme involves two steps. First, the simulation objects that contribute to small lookahead are merged together by using a merging algorithm. Then a partitioning algorithm is applied. The merging is needed to ensure a consistent performance for our dynamic scheme. Our dynamic scheme is tailor-made for an asynchronous simulation protocol that does not rely on null messages. The performance study on a supply-chain simulation shows that the partitioning algorithm and dynamic load balancing are important in achieving good performance.
Power electronic systems are described by nonlinear differential equations, typically of high order. simulation of such systems increasingly requires the high speeds available only on multiprocessor computing systems....
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ISBN:
(纸本)0780365615
Power electronic systems are described by nonlinear differential equations, typically of high order. simulation of such systems increasingly requires the high speeds available only on multiprocessor computing systems. However, the traditional methods for partitioning the system are rather inconvenient, primarily because of the additional burden created by the current operation associated with distributed systems. The concepts and methods of structural modeling provide a way to overcome this difficulty. The essence of structural modeling is the assignment of some specific computing resource to each object of the simulated physical system. The simulation of each object then operates as a formal independent procedure, and interactions between objects are implemented on a data link level. This allows parallel execution of the separate procedures on the allocated multiprocessor computing hardware. This provides two advantages: (1) a decrease in simulation time, and (2) simplification of the programming process.
We consider a quantum computational algorithm that can be used to determine (probabilistically) how close a given signal is to one of a set of previously observed signals stored in the state of a quantum neurocomputio...
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We consider a quantum computational algorithm that can be used to determine (probabilistically) how close a given signal is to one of a set of previously observed signals stored in the state of a quantum neurocomputional machine. The realization of a new quantum algorithm for factorization of integers by Shor and its implication to cryptography has created a rapidly growing field of investigation. Although no physical realization of a quantum computer is available, a number of software systems simulating a quantum computation process exist. In light of the rapidly increasing power of desktop computers and their ability to carry out these simulations, it is worthwhile to investigate possible advantages as well as realizations of quantum algorithms in signal processing applications. The algorithm presented offers a glimpse of the potential of this approach. Neural networks (NN) provide a natural paradigm for parallel and distributed processing of a wide class of signals. Neural networks within the context of classical computation have been used for approximation and classification tasks with some success. We propose a model for quantum neurocomputation (QN) and explore some of its properties and potential applications to signal processing in an information theoretic context.
This paper introduces a hybrid Associative memory/SIMD parallel processor, APPLES, which has been specifically designed for logic simulation. Its reviews the computational structure which permits parallel execution of...
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ISBN:
(纸本)0769500595
This paper introduces a hybrid Associative memory/SIMD parallel processor, APPLES, which has been specifically designed for logic simulation. Its reviews the computational structure which permits parallel execution of logic gate evaluations in memory. This facilitates fine grain execution on a massive scale of the basic tasks inherent in VLSI logic simulation. Furthermore, unlike of her SIMD approaches the simulation is not limited to a unit delay model, complex delays such as inertial delays are permissible. The processor has been implemented in Verilog and assessed using ISCAS-85 benchmarks. Gate evaluation is executed in constant time, whereas updating fan-out lists expands with circuit size. However, the APPLES architecture enables this latter task to be parallelised subject to various system parameters. The most important constraint is identified as the fan-out memory access time relative to the scan rate of the associative memory.
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