Ke-hsiung Chung

A performance comparison of event calendar algorithms: an empirical approach

We propose a suite of tests based on two‐state Markov chains for experimentally assessing the dynamic performance of a variety of simulation event calendar implementations. In contrast to previous studies based on the standard hold model for evaluation of performance statically, the proposed Markov hold model is more general and can be used to examine how different implementations respond dynamically to dependent sequences of insertion and deletion requests. The Markov hold model is used to conduct tests based on random, stressed, and correlated input sequences of requests, with performance measures including completion times, sensitivity to correlations, sensitivity to duplication, and efficiency of data‐handling. We apply these tests to fourteen different event calendar implementations. To demonstrate the utility of the proposed model, we also include a comparison of the event calendar algorithms on a token ring protocol with bursty Markovian packet‐traffic.

A simulation testbed based on lightweight processes

The Si lightweight‐process based system for simulating process interactions is an enhancement to the C programming languge in the form of library primitives with sets of predefined data structures. The Si system encapsulates an existing lightweight‐process library to provide a discrete‐event simulation environment supporting the process view. It was developed as a research testbed for investigating methods which support simulations efficiently. Easy extensions and modifications to the Si system are a major design objective, accomplished through modularity and layering. This paper describes the system, our experiences with its implementation, and its applicability to simulation modeling. We report on performance measurements of different implementations of the simulation scheduler, and of different algorithms for simulating service disciplines.

Efficient algorithms for simulating service disciplines

Abstract Efficient techniques for simulating the Round-Robin and Processor-Sharing service disciplines are presented. These schemes are general in that they can be applied in any discrete-event simulation view to improve execution performance. For the Round-Robin discipline, the proposed approach is based on computation instead of process switching. For the Processor-Sharing discipline, we introduce a lazy approach in combination with any efficient priority queue structure to reduce scheduling-relating computation. Using the S i simulation testbed for Simulating (process) i nteractions, the proposed algorithms are shown to be more efficient than the standard algorithms for simulating these service disciplines.

Computational Schemes For Efficient Simulation Of Service Disciplines

Eficient techniques for simulating the Round-Robin and Processor-Sharing service disciplines are presented. These schemes are general an that they can be applied in any discrete-event simulation view to improve execution performance. For the Round-Robin discipline, the proposed approach is based on computation instead of process switching. For the ProcessorSharing discipline, we introduce a lazy approach in combination with any eficient priority queue structure to reduce scheduling-related computation. Using the Si simulation testbed for Simulating (process) interactions, the proposed algorithms are shown to be more efficient than the standard algorithms for simulating these service disciplines.

Dynamic Performance Profiles Of Simulation Calendars

We propose a suite of tests based on two-state Markov chains for experimentally assessing the dynamic performance of a variety of simulation calendar implementations. In contrast to previous studies based on the standard hold model for evaluation of performance statically, the proposed Markov hold model is more general and can be used to examine how different implementations respond dynamically to dependent sequences of insertion and deletion requests. The Markov hold model is used to conduct tests based on random, stressed, and correlated input sequences of requests, with performance measures including completion times, sensitivity to correlations, sensitivity to duplication, and eficiency of data-handling. We apply these tests to fourteen different simulation calendar implementations.